Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
  • A61K47/30—Macromolecular organic or inorganic compounds, e.g. inorganic polyphosphates
  • A61K47/34—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyesters, polyamino acids, polysiloxanes, polyphosphazines, copolymers of polyalkylene glycol or poloxamers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K9/00—Medicinal preparations characterised by special physical form
  • A61K9/0012—Galenical forms characterised by the site of application
  • A61K9/0019—Injectable compositions; Intramuscular, intravenous, arterial, subcutaneous administration; Compositions to be administered through the skin in an invasive manner
  • A61K9/0024—Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/40—Polyamides containing oxygen in the form of ether groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/44—Polyester-amides
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G71/00—Macromolecular compounds obtained by reactions forming a ureide or urethane link, otherwise, than from isocyanate radicals in the main chain of the macromolecule
  • C08G71/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
  • C08L77/06—Polyamides derived from polyamines and polycarboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
  • C08L77/12—Polyester-amides
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G2230/00—Compositions for preparing biodegradable polymers

Definitions

• the invention relates, in general, to drug delivery systems and, in particular, to polymer compositions that can deliver a variety of different types of molecules in a controlled time release fashion.
• compositions that control the delivery profile of drugs either for sustained delivery or for rapid, but smooth, release, such as for delivery of cancer treatment and pain relief drugs.
• compositions as micro/nanospheres, liposomes, albumin conjugates, water-soluble prodrugs, cyclodextrin complexes and hydrogels have been attempted for such purposes, but with limited success due to a tendency of such compositions to release a large initial burst of drug with consequent failure of sustained delivery for a controlled time period.
• bioactive agents including peptides
• PEG polyethylene glycol
• the delivery profiles of such conjugates generally show that the half-life of the drug in circulation is proportional to the molecular weight of the PEG molecule used.
• the biokinetics and biodistribution of PEG have been shown to depend as well upon the size of the PEG molecules used.
• the present invention is based on the premise that oligo-ethylene glycol-containing (OEG-based) molecules can be introduced into the polymer backbone of poly(ester amide) (PEA), poly(ester urethane) (PEUR), and poly(ester urea) (PEU) polymers that contain at least one ⁇ -amino acid in the polymer backbone per repeat unit.
• PDA poly(ester amide)
• PEUR poly(ester urethane)
• PEU poly(ester urea)
• Such oligo-ethylene glycol- containing polymers are referred to herein as poly(ester ether amide) (PEEA), poly(ester ether urethane) (PEEUR) and poly(ester ether urea) (PEEU) and can be used to formulate biodegradable polymer compositions for rapid release of one or more dispersed bioactive agents in a consistent and reliable manner.
• PEEA poly(ester ether amide)
• PEEUR poly(ester ether urethane)
• PEEU poly(ester ether urea)
• biodegradable polymer compositions for rapid release of one or more dispersed bioactive agents in a consistent and reliable manner.
• such compositions can be used to release a bioactive agent contained therein with a smooth release rate profile within a period of about 24 hours.
• the invention provides an OEG-based composition in which a bioactive agent is dispersed in a biodegradable polymer.
• the polymer contains at least one of the following a) through f): a) a poly(ester ether amide) (PEEA) having a chemical formula described by structural formula (I),
• n ranges from about 15 to about 150; wherein, R 1 is independently selected from the group consisting of (C 2 - C 12 ) alkylene, (C 2 -C 12 ) alkenylene, and residues of ⁇ , ⁇ -dicarboxylates of formula (II), wherein R 5 in formula (II) is independently selected from the group consisting of (C 2 — C 4 ) alkylene and (C 2 -C 4 ) alkenylene and R 7 is independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, except that at least one R 1 in each polymer is the residue of a ⁇ , ⁇ - dicarboxylate of formula (II) wherein R 7 is (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; the R 3 s in individual n monomers are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkylene
• R 4 is independently selected from (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, (C 2 -C 20 ) alkylene, (C 2 -C 20 ) alkenylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic-fragment of a l,4:3,6-dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol, and combinations thereof; o o 9 9
• n ranges from about 15 to about 150, m ranges about 0.1 to 0.9: p ranges from about 0.9 to 0.1; wherein R 1 is independently selected from the group consisting Of(C 2 - C 12 ) alkylene, (C 2 -C 12 ) alkenylene, and residues of ⁇ , ⁇ -dicarboxylates of formula (II), wherein R 5 in formula (II) is independently selected from the group consisting of (C 2 — C 4 ) alkylene and (C 2 -C 4 ) alkenylene and R 7 is independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, except that at least one R 1 in each polymer is the residue of a ⁇ , ⁇ - dicarboxylate of formula (II) ) wherein R 7 is (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene;
• R 2 is independently selected from the group consisting of hydrogen, (C 1 -C 12 ) alkyl, (C 6 -C 10 ) aryl (C 1 -C 6 ) alkyl or a protecting group;
• R 3 S in individual m monomers are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) aryl (C 1 -C 6 ) alkyl, and-(CH 2 ) 2 SCH 3 ;
• R 4 is independently selected from (C 2 -C 6 ) alkyloxy (C 2 -Ci 2 ) alkylene, (C 2 -C 20 ) alkylene, (C 2 -C 20 ) alkenylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic-fragment of a l,4:3,6-dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol, and combinations thereof; and
• R 8 is independently (C 1 -C 20 ) alkyl or (C 2 -C 20 ) alkenyl; c) a poly(ether urethane) (PEEUR) having a chemical formula described by structural formula (V),
• n ranges from about 15 to about 150
• R 3 S within an individual n monomer are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) aryl (C 1 -C 6 ) alkyl, and -(CH 2 ) 2 SCH 3 ; and
• R 4 and R 6 are independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic fragment of a l,4:3,6-dianhydrohexitols of structural formula (III), a fragment of 1,4-anhydroerythritol and combinations thereof, except that at least one of R 4 and R 6 in each polymer is selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; d) a PEEUR having a chemical structure described by general structural formula (VI)
• n ranges from about 15 to about 150
• m ranges about 0.1 to about 0.9
• p ranges from about 0.9 to about 0.1 ;
• R 2 is independently selected from the group consisting of hydrogen, (C 1 -C 12 ) alkyl, (C 1 -C O ) alkyl (C 6 -C 10 ) aryl, and a protecting group;
• R 3 S within an individual m monomer are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) 3TyI(C 1 -C 6 ) alkyl, and -(CHb) 2 SCH 3 ;
• R 4 and R 6 are independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH) 5 a bicyclic fragment of a l,4:3,6-dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol and combinations thereof, except that at least one of R 4 and R in each polymer is selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; and
• R 8 is independently (C 1 -C 20 ) alkyl or (C 2 -C 20 ) alkenyl; e) a poly(ether urea) (PEEU) having a chemical formula described by general structural formula (VII):
• n is about 15 to about 150
• R 3 S within an individual n monomer are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) aryl (C 1 -C 6 ) alkyl, and -(CH 2 ) 2 SCH 3 ; and
• R 4 is independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 - C 12 ) alkylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic fragment of a 1,4:3,6- dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol, and combinations thereof, except that at least one R 4 in each polymer is selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; and f) Formula VIII is a PEEU having a chemical formula described by structural formula (VIII)
• R 2 is independently the group consisting of hydrogen, (C 1 -C 12 ) alkyl or (C 6 -C 10 ) aryl;
• R 3 S within an individual m monomer are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) aryl (C 1 - C 6 )alkyl, and -(CHj) 2 SCH 3 ;
• R is independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic fragment of a 1,4:3,6- dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol and combinations thereof, except that at least one R 4 in each polymer is selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; and
• R 8 is independently (C 1 -C 20 ) alkyl or (C 2 -C 20 ) alkenyl.
• the invention provides a biodegradable OEG-based polymer having a chemical structure described by Formula I, IV, V, VI, VII, or VIII, above.
• the invention provides biodegradable micelle-forming polymer compositions useful for delivery of bioactive agents dispersed therein.
• the composition includes a polymer with repeating alternating units of a) a hydrophobic section containing at least one invention biodegradable OEG-based polymer having a chemical structure described by structural formula I, IV, V, VI, VII, or VIII, above joined to b) a water soluble section.
• the water soluble section is made of repeating alternating units of i) polyethylene glycol having a Mw of 400 Dalton to about 200 Dalton, and ii) at least one ionizable or polar amino acid.
• the repeating alternating units have substantially similar molecular weights and the molecular weight of the polymer is in the range from about 15 kDa to 300 kDa.
• the invention provides methods for delivering a bioactive agent to a subject by administering to the subject in vivo an invention OEG-based polymer composition containing at least one bioactive agent dispersed in at least one or a blend of the invention OEG-based biodegradable polymers having chemical structures described by structural formula structural formula I, IV, V, VI, VII, or VIII, above.
• the composition can be formulated as a liquid dispersion of polymer particles with at least one bioactive agent disbursed therein. The particles biodegrade by enzymatic action at the surface thereof to release the bioactive agent with substantially zero-order release kinetics over a period of about 24 hours.
• Fig. 1 is a graph showing the effect of enzyme ( ⁇ -chymotrypsin) concentration on the weight loss kinetics of invention OEG-based PEA, AP3EG, at 37 0 C, and pH 7.4.
• PBS buffer serves as the control.
• (- ⁇ -) PBS buffer;
• (-•-) ⁇ -chymotrypsin at 0.05 mg/mL;
• (- A-) ⁇ -chymotrypsin at 0.10 mg/mL;
• (- ⁇ -) ⁇ -chymotrypsin at 0.20 mg/mL.
• Figs. 3 A-C are graphs showing in vitro lipase catalyzed biodegradation as compared with that in pure phosphate buffered medium in terms of weight loss in mg/cm of three invention PEEURs as compared with that of PEA 8-L-Leu-6, which contains no OEG segment.
• Fig. 3 A EG2-Leu-2;
• Fig. 3B EG3-Leu-2;
• Fig. 3C EG4-Leu-2.
• Curve a) lipase catalyzed phosphate buffered medium with pH 7.4, t 37°C; curve b) pure phosphate buffered medium; curve c) degradation of PEA 8-L-Leu-6 in lipase catalyzed phosphate buffered medium.
• the invention is based on the discovery that ⁇ -amino acid-containing PEA, PEUR and PEU polymers that contain backbone segments having one or more ester linkages between the amino acids are fully biodegradable so long as the OEG-based backbone segments upon biodegradation form OEGs with a molecular weight (Mw) in the range from about 44 (monoethyleneglycol) up to, but not including 400 Da.
• Mw molecular weight
• the at least one ester linkage in the polymer backbone is readily introduced in the diol components (and the di- acids in the case of PEEAs) used in polycondensation of the invention family of polymers.
• PEEA, PEEUR and PEEU polymers Due to structural properties of the invention PEEA, PEEUR and PEEU polymers, comnositions made using such polymers can be tailored to achieve a release rate of disbursed bioactive agents suitable to meet various therapeutic goals. For example, particles and films made using such polymers can be designed to biodegrade with a release rate similar to a twenty four hour infusion without a large initial burst of drug release and having a substantially zero-order release profile.
• the invention provides biodegradable polymer compositions containing at least one bioactive agent disbursed in at least one of a family of biodegradable polymers, which are referred to herein as poly(ether ester amide)s (PEEAs), poly(ether ester urethane)s (PEEURs) and poly(ether ester urea)s (PEEUs).
• PEEAs poly(ether ester amide)s
• PEEURs poly(ether ester urethane)s
• PEEUs poly(ether ester urea)s
• the polymers including the OEG-based segments thereof, are fully biodegradable without formation of irritants (R. Mehvar, J. Pharm Pharmaceut Sci (2000) 3(1): 125-136; and T. Yamaoka, J Pharm Sci (1994) Apr, 83(4):601-6).
• OEG segments of 400 Da or less are screened from the circulation by the endoreticular and renal system in mammals, the polymer degradation products and any bioactive agents that may have been dispersed in the polymers are cleared from the circulation upon enzymatic biodegradation.
• the invention PEEA, PEEUR and PEEU polymers are made by using at least one diol (or di-acid in the case of PEEAs) containing OEG-based segments with molecular weights of 400 Da or less during fabrication of the polymers. If only such diols and di-acids are used in fabrication, the PEEA, PEEUR and PEEU polymers produced are analogs of known PEG-containing polymers, but upon biodegradation the major breakdown products are ⁇ -amino acids, such as biological ⁇ -amino acids, and OEG segments of 44 up to, but less than 400 Da.
• the invention polymers and compositions based thereon are readily biodegraded by mammalian subjects without the irritation that results from break down of polymers containing OEG segments of greater molecular weight, such as is the case with polymers that form PEG breakdown products (i.e., those with a Mw of 400 Da or greater).
• the invention provides a composition comprising at least one bioactive agent dispersed in a biodegradable OEG-based polymer comprising at least one or a blend of the following a) through f): a) a poly(ester ether amide) (PEEA) having a chemical formula described by structural formula (I),
• n ranges from about 15 to about 150; wherein, R 1 is independently selected from the group consisting of (C 2 - C 12 ) alkylene, (C 2 -C 12 ) alkenylene, and residues of ⁇ , ⁇ -dicarboxylates of formula (II), wherein R 5 in formula (II) is independently selected from the group consisting of (C 2 — C 4 ) alkylene and (C 2 -C 4 ) alkenylene and R 7 is independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, except that at least one R 1 in each polymer is the residue of a ⁇ , ⁇ - dicarboxylate of formula (II) wherein R 7 is (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; the R 3 S in individual n monomers are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl,
• R 4 is independently selected from (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, (C 2 -C 20 ) alkylene, (C 2 -C 20 ) alkenylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic-fragment of a l,4:3,6-dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol, and combinations thereof;
• n ranges from about 15 to about 150, m ranges about 0.1 to 0.9: p ranges from about 0.9 to 0.1; wherein R 1 is independently selected from the group consisting of (C 2 - C 12 ) alkylene, (C 2 -C 12 ) alkenylene, and residues of ⁇ , ⁇ -dicarboxylates of formula (II), wherein R in formula (II) is independently selected from the group consisting of (C 2 - C 4 ) alkylene and (C 2 -C 4 ) alkenylene and R 7 is independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, except that at least one R 1 in each polymer is the residue of a ⁇ , ⁇ - dicarboxylate of formula (II) ) wherein R 7 is (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene;
• R 2 is independently selected from the group consisting of hydrogen, (C 1 -C 12 ) alkyl, (C 6 -C 1O ) aryl (C 1 -C 6 ) alkyl or a protecting group;
• R 3 S in individual m monomers are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) aryl (C 1 -C 6 ) alkyl, and-(CH 2 ) 2 SCH 3 ;
• R 4 is independently selected from (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, (C 2 -C 20 ) alkylene, (C 2 -C 20 ) alkenylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic-fragment of a l,4:3,6-dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol, and combinations thereof; and
• R 8 is independently (C 1 -C 20 ) alkyl or (C 2 -C 20 ) alkenyl; c) a poly(ether urethane) (PEEUR) having a chemical formula described by structural formula (V),
• n ranges from about 15 to about 150;
• R 3 S within an individual n monomer are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 1 Q) aryl (C 1 -C 6 ) alkyl, and -(CH 2 ) 2 SCH 3 ; and
• R 4 and R 6 are independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic fragment of a l,4:3,6-dianhydrohexitols of structural formula (III), a fragment of 1,4-anhydroerythritol and combinations thereof, except that at least one of R 4 and R 6 in each polymer is selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; d) a PEEUR having a chemical structure described by general structural formula (VI)
• n ranges from about 15 to about 150
• m ranges about 0.1 to about 0.9
• p ranges from about 0.9 to about 0.1
• R 2 is independently selected from the group consisting of hydrogen, (C 1 -C 12 ) alkyl, (C 1 -C 6 ) alkyl (C 6 -C 1 O) aryl, and a protecting group;
• R 3 S within an individual m monomer are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) 3TyI(C 1 -C 6 ) alkyl, and -(CH 2 ) 2 SCH 3 ;
• R 4 and R 6 are independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic fragment of a l,4:3,6-dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol and combinations thereof, except that at least one of R 4 and R 6 in each polymer is selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; and
• R is independently (C 1 -C 2O ) alkyl or (C 2 -C 20 ) alkenyl; e) a poly(ether urea) (PEEU) having a chemical formula described by general structural formula (VII):
• n is about 15 to about 150
• R 3 S within an individual n monomer are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) aryl (C 1 -C 6 ) alkyl, and -(CH 2 ) 2 SCH 3 ; and
• R 4 is independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 - C 12 ) alkylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic fragment of a 1,4:3,6- dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol, and combinations thereof, except that at least one R 4 in each polymer is selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; and f) a PEEU having a chemical formula described by structural formula
• n is about 15 to about 150;
• R 2 is independently the group consisting of hydrogen, (C 1 -C 12 ) alkyl or (C 6 -C 1O ) aryl;
• R s within an individual m monomer are independently selected from the group consisting of hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, (C 6 -C 10 ) aryl (C 1 - C 6 )alkyl, and -(CH 2 ) 2 SCH 3 ;
• R is independently selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene, CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH), a bicyclic fragment of a 1,4:3,6- dianhydrohexitol of structural formula (III), a fragment of 1,4-anhydroerythritol and combinations thereof, except that at least one R 4 in each polymer is selected from the group consisting of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene; and
• R 8 is independently (Ci-C 20 ) alkyl or (C 2 -C 20 ) alkenyl.
• the R 7 in each n monomer is (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene and R 4 is selected from the group consisting OfCH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH) and any one of (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene.
• the polymer will biodegrade to form from 15 to 300 OEGs having Mw of 44 up to, but not including, 400 Da.
• R 4 or R in each n monomer is selected from the group consisting of CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH) and (C 2 -C 6 ) alkyloxy (C 2 -C 12 ) alkylene.
• both R 4 and R in each n monomer are selected from the group consisting OfCH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH) and (C 2 -C 4 ) alkyloxy (C 2 -C 8 ) alkylene.
• the polymer will biodegrade to form from 15 to 300 OEGs having Mw of 44 up to, but not including, 400 Da.
• R 4 in each n monomer is selected from the group consisting Of CH 2 CH(OH)CH 2 , CH 2 CH(CH 2 OH) 5 and (C 2 -C 4 ) alkyloxy (C 2 -C 8 ) alkylene.
• the polymer will biodegrade to form from 15 to 300 OEGs having Mw of 44 up to, but not including, 400 Da.
• alkenyl refers to straight or branched chain hydrocarbyl groups having one or more carbon-carbon double bonds.
• alkynyl refers to straight or branched chain hydrocarbyl groups having at least one carbon-carbon triple bond.
• aryl refers to aromatic groups having in the range of 6 up to 14 carbon atoms.
• lysine monomer residues (ii) are linked either to themselves or to each other by a diacid monomer residue (iii) for PEEA, by a diol residue (iii) for PEEUR or carbonyl (iii) for PEEU.
• a diacid monomer residue (iii) for PEEA by a diol residue (iii) for PEEUR or carbonyl (iii) for PEEU.
• Each polymer chain is therefore a statistical, but non-random, string of monomer residues composed of integer numbers of monomers, i, ii and iii.
• the ratios of monomer residues "m" and "p” m formulas (IV, VI and VIII) will not be whole numbers (rational integers).
• the numbers of monomers i, ii and iii averaged over all of the chains i.e. normalized to the average chain length
• ratios can only take irrational values (i.e., any real number that is not a rational number).
• Irrational numbers are derived from ratios that are not of the form n/j, where n and j are integers.
• amino acid and ⁇ -amino acid mean a chemical compound containing an amino group, a carboxyl group and a pendent R group, such as the R 3 groups defined herein.
• biological ⁇ -amino acid means the amino acid(s) used in synthesis are selected from phenylalanine, leucine, glycine, alanine, valine, isoleucine, methionine, or a mixture thereof.
• adirectional amino acid means a chemical moiety within the polymer chain obtained from an ⁇ -amino acid, such that the R group (for example R 8 in formulas VI and VIII) is inserted within the polymer backbone.
• bioactive agent means a bioactive agent as disclosed herein that is dispersed in the polymer of the invention composition.
• dispersed is used to refer to bioactive agents means that the bioactive agent is mixed into, dissolved in, homogenized with, and/or covalently bound to a polymer, for example, attached to a functional group in the polymer of the composition or to the surface of a polymer particle.
• bioactive agents may include, without limitation, small molecule drugs, peptides, proteins, DNA, cDNA, RNA, sugars, lipids and whole cells.
• the bioactive agents can be administered in polymer particles having a variety of sizes and structures suitable to meet differing therapeutic goals and routes of administration.
• biodegradable as used herein to describe the invention OEG-based polymer compositions means the polymer used therein is capable of being broken down into innocuous products in the normal functioning of the body. This is particularly true when the amino acids used in fabrication of the invention polymers are biological L- ⁇ -amino acids and the diol and di-acids used in fabrication of the polymer form OEG segments of 44 up to, but not including 400 Da upon biodegradation.
• the polymers in the invention OEG-based polymer compositions include hydrolyzable ester and enzymatically cleavable amide linkages that provide biodegradability, and are typically chain terminated, predominantly with amino groups.
• the amino termini of the polymers can be acetylated or otherwise capped by conjugation to any other acid-containing, biocompatible molecule, to include without restriction organic acids, bioinactive biologies, and bioactive agents as described herein.
• the entire polymer composition, and any particles made thereof, is substantially biodegradable.
• At least one of the ⁇ -amino acids used in fabrication of the invention OEG-based polymers is a biological ⁇ -amino acid.
• the biological ⁇ -amino acid used in synthesis is L-phenylalanine.
• the polymer contains the biological ⁇ -amino acid, L- leucine.
• R 3 S By varying the R 3 S within monomers as described herein, other biological ⁇ -amino acids can also be used, e.g., glycine (when the R s are H), alanine (when the R s are CH 3 ), valine (when the R 3 S are CH(CH 3 ) 2 , isoleucine (when the R 3 S are CH(CH 3 )CH 2 CH 3 ), phenylalanine (when the R s are CH 2 C 6 H 5 ), or methionine (when the R s are (CH 2 ) 2 SCH 3 ), and combinations thereof.
• all of the various ⁇ -amino acids contained in the polymers used in making the invention OEG-based polymer compositions are biological ⁇ -amino acids, as described herein.
• the polymer compositions can be formulated to provide a variety of properties, m one embodiment, particles of the invention PEEA, PEEUR and PEEU polymers are sized to agglomerate in vivo forming a time-release polymer depot when injected in vivo for local delivery of bioactive agents dispersed therein to surrounding tissue/cells.
• the invention provides methods for delivering one or more bioactive agents to a local site in the body in a subject.
• the invention methods involve injecting into an in vivo site in the body of the subject an invention OEG-based polymer composition that has been formulated as polymer particles with at least one bioactive agent dispersed therein.
• the injected particles agglomerate to form a polymer depot of particles of increased size and the agglomeration will slowly release the individual particles, which will biodegrade by enzymatic action as described herein to release the dispersed bioactive agent(s).
• each polymer molecule After biodegradation, each polymer molecule also will release into the circulation from 15 to 300 oligo-ethylene glycol (OEG) molecules having a molecular weight of 44 up to, but not including 400 Da. As described herein, the number of oligo-ethylene glycol (OEG) molecules having a molecular weight of 400 Da or less released by biodegradation of any particular polymer will depend upon selection of the diols and di-acids used in fabrication of the polymer.
• a dispersion of the OEG-based PEEA, PEEUR or PEEU particles can be injected parenterally, for example subcutaneously, intramuscularly, or into an interior body site, such as an organ.
• Polymer particles of sizes capable of passing through pharmaceutical syringe needles ranging in size from about 19 to about 27 Gauge, for example those having an average diameter in the range from about 1 ⁇ m to about 200 ⁇ m can be injected into an interior body site, and will agglomerate to form particles of increased size that form a depot to dispense the dispersed bioactive agent(s) locally, hi other embodiments, the biodegradable polymer particles act as a carrier for the bioactive agent into the circulation for targeted and tuned release systemically.
• Invention polymer particles in the size range of about 10 nm to about 500 nm will enter directly into the circulation for such purposes.
• the biodegradable polymers used in the invention OEG-based polymer composition can be designed to tailor the rate of biodegradation of the polymer to result in controlled delivery of the bioactive agent over a period of time. For instance, typically, a thin disc of the invention composition will biodegrade by surface erosion in enzymatic solution (e.g., such as is found in vivo) so as to undergo a weight loss of about 81% to 56% weight loss within 24 hrs.
• the present invention utilizes biodegradable polymer particle-mediated delivery techniques to deliver a wide variety of bioactive agents in treatment of a wide variety of diseases and disease symptoms at a rate that can be engineered by selection of the polymer and particle size.
• Polymers suitable for use in the practice of the invention described by structural formula (I and IV-VIII) bear functionalities that allow facile covalent attachment of the bioactive agent(s) or covering molecule(s) to the polymer.
• a polymer bearing carboxyl groups can readily react with an amino moiety, thereby covalently bonding a peptide to the polymer via the resulting amide group.
• the biodegradable polymer and the bioactive agent may contain numerous complementary functional groups that can be used to covalently attach the bioactive agent to the biodegradable polymer.
• PEEURs synthesized by the polycondensation of active bis-carbonates (compounds 4a-c in Example 2) with oligo-ethylene glycol (OEG) based di-p-toluensulfonic acid salts (compound 2a-e below and in Example 2) can be useful as biodegradable analogs of PEGs for various chemical and biochemical applications:
• the monomers 2a-e can be synthesized by direct condensation of ⁇ -amino acids with OEG as are monomers described in the Examples below.
• ⁇ -amino acids of various hydrophobicities can be used for synthesizing the monomers 2a-e.
• the latter method will allow regulation of the hydrophilic/hydrophobic balance of the invention biodegradable OEG-based polymers.
• the properties and biological applications of the invention polymers and compositions can vary in a wide range.
• PEEAs, PEEURs and PEEUs like other polymers obtained via solution active polycondensation, contain two terminal groups that can be used to functionalize these polymers for their subsequent chemical / biochemical applications using methods known in the art and as described herein. Moreover, by interaction with mono- ethanol amine, the terminal active carbonate groups of the polymers can be transformed into oxy-ethyl urethane groups to enhance hydrophilicity of the polymers.
• terminal OH groups can be used for subsequent transformations, e.g. to attach acrylates.
• SH-terminated PEEURs can be synthesized by interaction with mercapto-amines.
• the SH-terminated PEEURs can be attached under mild conditions to polymers containing active double bond moieties, e.g. to fumaric acid based unsaturated PEAs, or can be used for subsequent transformations, as described below.
• PEEURs also can be used for chemical / photo-chemical grafting to other unsaturated polymers, e.g. to fumaric acid-based unsaturated PEAs, and the like, to render them hydrophilic or water soluble.
• PEEAs, PEEURs and PEEUs terminated with unsaturated maleimide cycles are of interest for the attachment of the polymers used in the invention compositions to HS- containing molecules, for example to proteins, enzymes, peptides, and the like, and can be synthesized in several ways.
• maleimide terminated polymers can be synthesized by interaction of terminal amino groups with excess of N.N'-alkylene-bis- maleimides or with active diester, e.g. N-maleimido- ⁇ -alanine.
• SH-terminated polymers formed as described above also can be used to synthesize maleimide terminated PEEAs, PEEURs and PEEUs by interaction of terminal amino groups with excess of N.N'-alkylene-bis-maleimides.
• the terminal active carbonate groups can be transformed into maleimide terminus according to the following scheme:
• the polymer in the invention OEG-based polymer composition plays an active role in the treatment processes at the site of local injection by holding the bioactive agent at the site of injection for a period of time sufficient to allow the individual's endogenous processes to interact with the bioactive agent, while releasing the particles or polymer molecules containing such agents during biodegradation of the polymer.
• the fragile bioactive agent is protected by the more slowly biodegrading polymer to increase half-life and persistence of the bioactive agent(s).
• the polymers disclosed herein upon enzymatic degradation, provide ⁇ -amino acids while the other breakdown products are either OEGs or, if not, are diols or di-acids that can be metabolized in the way that fatty acids and sugars are metabolized. Uptake of the polymer is safe: studies have shown that the subject can metabolize and clear the polymer degradation products.
• OEG-based polymer compositions are, therefore, substantially non-inflammatory to the subject both at the site of injection and systemically, apart from any trauma caused by injection itself.
• the PEEA, PEEUR and PEEU polymers useful in practicing the invention multiple different ⁇ -amino acids can be employed in a single polymer molecule.
• the polymers may comprise at least two different amino acids per repeat unit and a single polymer molecule may contain multiple different ⁇ -amino acids in the polymer molecule, depending upon the size of the molecule.
• the polymers described herein may also be used in a block co-polymer.
• the polymer is used as one block in di- or tri-block copolymers, which, for example, can be used to make micelles, as described below.
• the invention OEG-based polymer compositions and methods are members of the larger family of polyester amides (PEAs), polyester urethanes (PEURs) and polyester ureas (PEUs), many of which have built-in functional groups on side chains, and these built-in functional groups can react with other chemicals and lead to the incorporation of additional functional groups to expand the functionality of the polymers further.
• the OEG- based (i.e., PEEA, PEEUR or PEEU) polymers used in the invention methods are ready for reaction with other chemicals having a hydrophilic structure to increase water solubility and with bioactive agents and covering molecules, without the necessity of prior modification.
• OEG-based polymers used in the invention display minimal hydrolytic degradation when tested in a saline (PBS) medium, but in an enzymatic solution, such as lipase, chymotrypsin or CT, a uniform surface erosive behavior has been observed that forms a substantially zero-order release profile, as described herein.
• PBS saline
• Suitable protecting groups for use in the PEEA, PEEUR and PEEU polymers include ⁇ -butyl or another as is known in the art.
• Suitable l,4:3,6-dianhydrohexitols of general formula (III) include those derived from sugar alcohols, such as D-glucitol, D- mannitol, or L-iditol.
• Dianhydrosorbitol is the presently preferred bicyclic fragment of a l,4:3,6-dianhydrohexitol for use in the PEEA, PEEUR and PEEU polymers used in fabrication of the invention OEG-based polymer compositions.
• OEG Oletylene glycol
• OEG-containing (OEG-containing) moiety and oligo-ethylene glycol- based (OEG-based)” moiety are used herein to refer to polymer segments that release an OEG molecule upon enzymatic biodegradation of the polymer, which OEG may be either monodisperse or, more commonly, polydisperse with a polydispersity index in the range from about 1.05 up to 2.0.
• a polydisperse OEG molecule as described herein is characterized statistically by its weight average molecular weight )(Mw) and its number average molecular weight (Mn), the ratio of which is called the polydispersity index (Mw/Mn).
• the molecular weights and polydispersities herein are determined by gel permeation chromatography (GPC) using polystyrene standards. More particularly, number and weight average molecular weights (M n and M w ) are determined, for example, using a Model 510 gel permeation chromatography (Water Associates, Inc., Milford, MA) equipped with a high-pressure liquid chromatographic pump, a Waters 486 UV detector and a Waters 2410 differential refractive index detector. Tetrahydrofuran (THF), N,N-dimethylformamide (DMF) or N,N-dimethylacetamide (DMAc) is used as the eluent (1.0 mL/min). Polystyrene or poly(methyl methacrylate) standards having narrow molecular weight distribution were used for calibration.
• GPC gel permeation chromatography
• the ⁇ «- ⁇ , ⁇ -diamine is entered into a polycondensation reaction with a di-acid, such as adipic, sebacic or fumaric acid, or t ⁇ -activated esters, or bis-acyl chlorides, to obtain the final polymer having an OEG- containing moiety, as well as ester, ether and amide bonds (PEEA).
• a di-acid such as adipic, sebacic or fumaric acid, or t ⁇ -activated esters, or bis-acyl chlorides
• PEEA ester, ether and amide bonds
• an activated di-acid derivative e.g., bis-p ⁇ ra-nitrophenyl diester, can be used as an activated di-acid.
• a bis-di- carbonate such as bis(p-nitrophenyl) oligoether-containing dicarbonate
• a bis-di- carbonate such as bis(p-nitrophenyl) oligoether-containing dicarbonate
• a bis-di- carbonate such as bis(p-nitrophenyl) oligoether-containing dicarbonate
• ethylene oxide functionalities i.e., an OEG-containing moiety
• PEEUR polymers a final polymer is obtained having an OEG-containing moiety, as well as ester, ether and urethane bonds.
• OEG-containing di-acid-type compounds useful for active polycondensation according to the present invention are ⁇ , ⁇ -alkylene dicarboxylates of formula (III) composed of short aliphatic non toxic di-acids and OEGs as diols. [0053] These molecules inherently contain at least one ester group, which easily can be cleaved by biotic (enzymatic) and abiotic hydrolysis.
• PEEA, PEEUR and PEEU polymer compositions possess increased hydrophilicity and an increased number of ester groups in the backbone chain per unit as compared with previously known PEA, PEUR and PEU polymers, which ester groups in some cases confer more rapid biodegradability than polymers composed of aliphatic diols and di-acids with alkylene chains.
• the unsaturated PEEAs can be prepared by solution poly condensation of either (1) di-p-toluene sulfonic acid salt of bis( ⁇ -amino acid) di-ester of unsaturated diol and di-p- n iu - nn u ⁇ ⁇ ⁇ o+ er of saturated dicarboxylic acid or (2) di-p-toluene sulfonic acid salt of bis ( ⁇ - amino acid) diester of saturated diol and di-nitrophenyl ester of unsaturated dicarboxylic acid or (3) di-p-toluene sulfonic acid salt of bis( ⁇ -amino acid) diester of unsaturated diol and di- nitrophenyl ester of unsaturated dicarboxylic acid.
• at least one, and preferably all, of the diols and/or di-acids used in fabrication contains from one to eight ether functionalities.
• Salts of p-toluene sulfonic acids are known for use in synthesizing polymers containing amino acid residues.
• the aryl sulfonic acid salts are used instead of the free base because the aryl sulfonic salts of bis ( ⁇ -amino acid) diesters are easily purified through recrystallization and render the amino groups as unreactive ammonium tosylates throughout workup.
• the nucleophilic amino group is readily revealed through the addition of an organic base, such as triethylamine, so the polymer product is obtained in high yield.
• the di-p-nitrophenyl esters of unsaturated dicarboxylic acid can be synthesized from p-nitrophenyl and unsaturated dicarboxylic acid chloride, e.g., by dissolving triethylamine and p-nitrophenol in acetone and adding unsaturated dicarboxylic acid chloride dropwise with stirring at -78°C and pouring into water to precipitate product.
• Suitable acid chlorides included fumaric, maleic, mesaconic, citraconic, glutaconic, itaconic, ethenyl-butane dioic and 2-propenyl-butanedioic acid chlorides.
• dicarbonate monomers of general structure (X) are employed for polymers of structural formula (V) and (VI), wherein each R 10 is independently (C 6 -C 10 ) aryl optionally substituted with one or more nitro, cyano, halo, trifiuoromethyl, or trifiuoromethoxy; and R 6 can be as described above.
• the di-aryl sulfonic acid salts of diesters of ⁇ -amino acid and unsaturated diol can be prepared by admixing ⁇ -amino acid, e.g., p-aryl sulfonic acid monohydrate and saturated or unsaturated diol in toluene, heating to reflux temperature, until water evolution is minimal, then cooling.
• ⁇ -amino acid e.g., p-aryl sulfonic acid monohydrate
• saturated or unsaturated diol in toluene
• the unsaturated diols that do not contain ether functionalities include, for example, 2-butene-l,3-diol and l,18-octadec-9-en-diol.
• Saturated di-p-nitrophenyl esters of dicarboxylic acid and saturated di-p-toluene sulfonic acid salts of bis- ⁇ -amino acid esters can be prepared as described in U.S. Patent No. 6,503,538 Bl.
• Synthesis of the unsaturated poly(ester amide)s (UPEAs) useful as biodegradable polymers are known in the art (See e.g., U.S. Patent Nos. 5,516, 881; 6,476,204; 6,503,538).
• Synthesis of unsaturated PEEAs of the structural formula (I) is as disclosed above and as described in Example 1 herein.
• an amino substituted aminoxyl (N-oxide) radical bearing group e.g., 4- amino TEMPO
• carbonyldiimidazol or suitable carbodiimide
• Bioactive agents as described herein, can be attached via the double bond functionality. Hydrophilicity can be imparted by bonding to poly(ethylene glycol) diacrylate.
• the biodegradable PEEA, PEEUR and PEEU polymers can contain from one to multiple different ⁇ -amino acids per polymer molecule and preferably have weight average molecular weights ranging from 10,000 to 125,000 g/mol; these polymers and copolymers typically have intrinsic viscosities at 25 0 C, determined by standard viscosimetric methods, ranging from 0.3 to 3.0, for example, ranging from 0.5 to 1.5.
• an amino substituted aminoxyl (N-oxide) radical bearing group e.g., 4- amino TEMPO
• carbonyldiimidazole or suitable carbodiimide, as a condensing agent.
• the invention high Mw PEEUs having structural formula (VII) can be prepared inter-facially by using phosgene as a bis-electrophilic monomer in a chloroform/water system, as shown in the reaction scheme (II) below:
• a 20% solution of phosgene (highly toxic) in toluene, can be replaced either by diphosgene (trichloromethylchloroformate) or triphosgene (bis(trichloromethyl)carbonate).
• diphosgene trichloromethylchloroformate
• triphosgene bis(trichloromethyl)carbonate.
• Less toxic carbonyldiimidazole can be also used as a bis-electrophilic monomer instead of phosgene, di-phosgene, or tri-phosgene.
• PEU polymers fabricated have been obtained as solutions in chloroform and these solutions are stable during storage. However, some polymers, for example, l-Phe-4, become insoluble in chloroform after separation. To overcome this problem, PEEU polymers can be separated from chloroform solution by casting onto a smooth hydrophobic surface and allowing chloroform to evaporate to dryness. No further purification of obtained PEEUs is needed. General procedures to preparation of PEUs are described in published U. S application US2007/0128250-A1. [0067] Polymers useful in the invention OEG-based polymer compositions, such as PEEA, PEEUR and PEEU polymers, biodegrade by enzymatic action at the surface.
• the polymers for example particles thereof, administer the bioactive agent to the subject at a controlled release rate, for which the kinetics have been observed to be close to zero order.
• the invention OEG-based polymer compositions are substantially non-inflammatory. Even the OEGs incorporated therein are of such low Mw that they can be cleared from the body once liberated from the polymer after biodegradation.
• dispensersed means at least one bioactive agent as disclosed herein is dispersed, mixed, dissolved, homogenized, and/or covalently bound (“dispersed”) in a polymer particle, for example attached to the surface of the particle.
• bioactive agents can be dispersed within the polymer matrix without chemical linkage to the polymer carrier, it is also contemplated that the bioactive agent or a covering molecule can be covalently bound to the biodegradable polymers via a wide variety of suitable functional groups.
• the biodegradable polymer is a polyester
• the carboxyl group chain end can be used to react with a complimentary moiety on the bioactive agent or covering molecule, such as hydroxy, amino, thio, and the like.
• suitable reagents and reaction conditions are disclosed, e.g., in March 's Advanced Organic Chemistry, Reactions, Mechanisms, and Structure, Fifth Edition, (2001); and Comprehensive Organic Transformations, Second Edition, Larock (1999).
• a bioactive agent can be linked to the PEEA, PEEUR or PEEU polymers described herein through an amide, ester, ether, amino, ketone, thioether, sulfinyl, sulfonyl, disulfide linkage.
• Such a linkage can be formed from suitably functionalized starting materials using synthetic procedures that are known in the art.
• a polymer can be linked to the bioactive agent via an end or pendent carboxyl group (e.g., COOH) of the polymer.
• carboxyl group e.g., COOH
• a compound of structures, IV, VI and VIII can react with an amino functional group or a hydroxyl functional group of a bioactive agent to provide a biodegradable polymer having the bioactive agent attached via an amide linkage or carboxylic ester linkage, respectively.
• the carboxyl group of the polymer can be benzylated or transformed into an acyl halide, acyl anhydride/"mixed" anhydride, or active ester.
• the free -NH 2 ends of the polymer molecule can be acylated to assure that the bioactive agent will attach only via a carboxyl group of the polymer and not to the free ends of the polymer.
• PEG poly (ethylene glycol)
• PC phosphoryl choline
• polysaccharides including polysialic acid
• poly(ionizable or polar amino acids) including polyserine, polygluta
• the Mws of OEG molecules formed upon biodegradation of a single particle, including covering molecules can be substantially any Mw in the range from about 44 (monoethyleneglycol) up to, but not including 400 Da, so that the Mws of the various PEG molecules attached to the particle can be varied.
• the bioactive agent or covering molecule can be attached to the polymer via a linker molecule.
• a linker may be utilized to indirectly attach the bioactive agent to the biodegradable polymer, hi certain embodiments, the linker compounds include poly(ethylene glycol) having a Mw of about 44 up to 400 Da, preferably 200 up to 400; amino acids, such as serine; polypeptides with repeat number from 1 to 100; and any other suitable low molecular weight polymers.
• the linker typically separates the bioactive agent from the polymer by about 5 angstroms up to about 200 angstroms.
• alkyl refers to a straight or branched chain hydrocarbon group including methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, and the like.
• alkenyl refers to straight or branched chain hydrocarbyl groups having one or more carbon-carbon double bonds.
• alkynyl refers to straight or branched chain hydrocarbyl groups having at least one carbon-carbon triple bond.
• aryl refers to aromatic groups having in the range of 6 up to 14 carbon atoms.
• the linker may be a polypeptide having from about 2 up to about 25 amino acids.
• Suitable peptides contemplated for use include poly-L-glycine, poly- L-lysine, poly-L-glutamic acid, poly-L-aspartic acid, poly-L-histidine, poly-L-ornithine, poly-L-serine, poly-L-threonine, poly-L-tyrosine, poly-L-leucine, poly-L-lysine-L- phenylalanine, poly-L-arginine, poly-L-lysine-L-tyrosine, and the like.
• the bioactive agent covalently crosslinks the polymer, i.e. the bioactive agent is bound to more than one polymer molecule. This covalent crosslinking can be done with or without additional polymer-bioactive agent linker.
• bioactive agent molecule can also be incorporated into an intramolecular bridge by covalent attachment between two polymer molecules.
• a linear polymer polypeptide conjugate is made by protecting the potential nucleophiles on the polypeptide backbone and leaving only one reactive group to be bound to the polymer or polymer linker construct. Deprotection is performed according to methods well known in the art for deprotection of peptides (Boc and Fmoc chemistry for example).
• a polypeptide bioactive agent is presented as retro-inverso or partial retro-inverso peptide.
• the bioactive agent is mixed with a photocrosslinkable version of the polymer in a matrix, and after crosslinking the material is dispersed (ground) to an average diameter in the range from about 0.1 to about lO ⁇ m.
• the linker can be attached first to the polymer or to the bioactive agent or covering molecule.
• the linker can be either in unprotected form or protected form, using a variety of protecting groups well known to those skilled in the art.
• the unprotected end of the linker can first be attached to the polymer or the bioactive agent or covering molecule.
• the protecting group can then be de-protected using PdTH 2 hydrogenolysis, mild acid or base hydrolysis, or any other common de-protection method that is known in the art.
• the de-protected linker can then be attached to the bioactive agent or covering molecule, or to the polymer
• a polyester can be reacted with an amino-substituted aminoxyl (N-oxide) radical bearing group, e.g., 4-amino-2,2,6,6-tetramethylpiperidine-l-oxy, in the presence of N 9 N'- carbonyldiimidazole to replace the hydroxyl moiety in the carboxyl group at the chain end of the polyester with an amino-substituted aminoxyl-(N-oxide) radical bearing group, so that the amino moiety covalently bonds to the carbon of the carbonyl residue of the carboxyl group to form an amide bond.
• N-oxide amino-substituted aminoxyl
• the N,N'-carbonyl diimidazole or suitable carbodiimide converts the hydroxyl moiety in the carboxyl group at the chain end of the polyester into an intermediate product moiety which will react with the aminoxyl, e.g., 4-amino-2,2,6,6- tetramethylpiperidine-1-oxy.
• the aminoxyl reactant is typically used in a mole ratio of reactant to polyester ranging from 1:1 to 100: 1.
• the mole ratio of N,N'-carbonyl diimidazole to aminoxyl is preferably about 1:1.
• a typical reaction is as follows.
• a polyester is dissolved in a reaction solvent and reaction is readily carried out at the temperature utilized for the dissolving.
• the reaction solvent may be any in which the polyester will dissolve.
• the polyester is a polyglycolic acid or a poly(glycolide-L-lactide) (having a monomer mole ratio of glycolic acid to L-lactic acid greater than 50:50), highly refined (99.9+% pure) dimethyl sulfoxide at 115 0 C to 130 0 C or DMSO at room temperature suitably dissolves the polyester.
• polyester is a poly- L-lactic acid
• a poly-DL-lactic acid or a poly(glycolide-L-lactide) having a monomer mole ratio of glycolic acid to L-lactic acid 50:50 or less than 50:50
• tetrahydrofuran tetrahydrofuran
• dichloromethane DCM
• chloroform at room temperature to 40 ⁇ 50 0 C suitably dissolve the polyester.
• the polymers used to make the invention OEG-based polymer compositions as described herein have one or more bioactive agent directly linked to the polymer.
• the residues of the polymer can be linked to the residues of the one or more bioactive agents.
• one residue of the polymer can be directly linked to one residue of the bioactive agent.
• the polymer and the bioactive agent can each have one open valence.
• more than one bioactive agent, multiple bioactive agents, or a mixture of bioactive agents having different therapeutic or palliative activity can be directly linked to the polymer.
• the residue of each bioactive agent can be linked to a corresponding residue of the polymer, the number of residues of the one or more bioactive agents can correspond to the number of open valences on the residue of the polymer.
• a "residue of a polymer” refers to a radical of a polymer having one or more open valences. Any synthetically feasible atom, atoms, or functional group of the polymer (e.g., on the polymer backbone or pendant group) of the present invention can be removed to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a bioactive agent. Additionally, any synthetically feasible functional group (e.g., carboxyl) can be created on the polymer (e.g., on the polymer backbone or pendant group) to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a bioactive agent. Based on the linkage that is desired, those skilled in the art can select suitably functionalized starting materials that can be derived from the polymer of the present invention using procedures that are known in the art.
• a "residue of a compound of structural formula (*)” refers to a radical of a compound of polymer formulas (I) and (IV- VIII) as described herein having one or more open valences. Any synthetically feasible atom, atoms, or functional group of the compound (e.g., on the polymer backbone or pendant group) can be removed to provide the open valence, provided bioactivity is substantially retained when the radical is attached to a residue of a bioactive agent.
• any synthetically feasible functional group e.g., carboxyl
• any synthetically feasible functional group e.g., carboxyl
• any synthetically feasible functional group can be created on the compound of formulas (I) and (IV-VIII) (e.g., on the polymer backbone or pendant group) to provide the open valance, provided bioactivity is substantially retained when the radical is attached to a residue of a bioactive agent.
• suitably functionalized starting materials that can be derived from the compound of formulas (I) and (IV-VIII) using procedures that are known in the art.
• Such a linkage can be formed from suitably functionalized starting materials using synthetic procedures that are known in the art. Based on the linkage that is desired, those skilled in the art can select suitably functional starting material that can be derived from a residue of a compound of structural formula (I) or (IV) and from a given residue of a bioactive agent or adjuvant using procedures that are known in the art. The residue of the bioactive agent or adjuvant can be linked to any synthetically feasible position on the residue of a compound of structural formula (I) or (IV). Additionally, the invention also provides compounds having more than one residue of a bioactive agent or adjuvant bioactive agent directly linked to a compound of structural formula (I) or (IV).
• bioactive agents that can be linked to the polymer molecule can typically depend upon the molecular weight of the polymer. For example, for a compound of structural formula (I), wherein n is about 5 to about 150, preferably about 5 to about 70, up to about 150 bioactive agent molecules (i.e., residues thereof) can be directly linked to the polymer (i.e., residue thereof) by reacting the bioactive agent with side groups of the polymer, hi unsaturated polymers, the bioactive agents can also be reacted with double bonds in the polymer.
• PEEA, PEEUR and PEEU polymers described herein absorb water, (5 to 25 % w/w water up-take, on polymer film.) allowing hydrophilic molecules to readily diffuse therethrough. This characteristic makes these polymers suitable for use as an over coating on particles to control release rate. Water absorption also enhances biocompatibility of the polymers and the polymer composition based on such polymers.
• due to the hydrophilic properties of the PEEA, PEEUR and PEEU polymers when delivered in vivo the particles become sticky and agglomerate, particularly at in vivo temperatures. Thus the polymer particles spontaneously form polymer depots when injected subcutaneously or intramuscularly for local delivery, such as by subcutaneous needle or needle-less injection.
• Particles with average diameter range from about 1 micron to about 100 microns, which size will not circulate efficiently within the body, are suitable for forming such polymer depots in vivo.
• the GI tract can tolerate much larger particles, for example micro particles of about 1 micron up to about 1000 microns average diameter.
• OEG-based polymer compositions can be made using immiscible solvent techniques. Generally, these methods entail the preparation of an emulsion of two immiscible liquids.
• a single emulsion method can be used to make polymer particles that incorporate at least one hydrophobic bioactive agent, hi the single emulsion method, bioactive agents to be incorporated into the particles are mixed with polymer in solvent first, and then emulsified in water solution with a surface stabilizer, such as a surfactant.
• polymer particles with hydrophobic bioactive agent conjugates are formed and suspended in the water solution, in which hydrophobic conjugates in the particles will be stable without significant elution into the aqueous solution, but such molecules will elute into body tissue, such as muscle tissue.
• a double emulsion method can be used to make polymer particles with interior aqueous phase and hydrophilic bioactive agents dispersed within.
• aqueous phase or hydrophilic bioactive agents dissolved in water are emulsified in polymer lipophilic solution first to form a primary emulsion, and then the primary emulsion is put into water to emulsify again to form a second emulsion, in which particles are formed having a continuous polymer phase and aqueous bioactive agent(s) in the dispersed phase.
• Surfactant and additive can be used in both emulsifications to prevent particle aggregation.
• Chloroform or DCM which are not miscible in water, are used as solvents for PEA and PEUR polymers, but later in the preparation the solvent is removed, using methods known in the art.
• low water solubility means a bioactive agent that is less hydrophobic than truly lipophilic drugs, such as Taxol, but which are less hydrophilic than truly water-soluble drugs, such as many biologies.
• These types of intermediate compounds are too hydrophilic for high loading and stable matrixing into single emulsion particles, yet are too hydrophobic for high loading and stability within double emulsions.
• a polymer layer is coated onto particles made of polymer and drugs with low water solubility, by a triple emulsion process. This method provides relatively low drug loading (-10% w/w), but provides structure stability and controlled drug release rate.
• the first emulsion is made by mixing the bioactive agents into polymer solution and then emulsifying the mixture in aqueous solution with surfactant or lipid, such as di-(hexadecanoyl)phosphatidylcholine (DHPC; a short-chain derivative of a natural lipid).
• surfactant or lipid such as di-(hexadecanoyl)phosphatidylcholine (DHPC; a short-chain derivative of a natural lipid.
• DHPC di-(hexadecanoyl)phosphatidylcholine
• the second emulsion is formed by putting the first emulsion into a polymer solution, and emulsifying the mixture, so that water drops with the polymer/drug particles inside are formed within the polymer solution.
• Water and surfactant or lipid will separate the particles and dissolve the particles in the polymer solution.
• the third emulsion is then formed by putting the second emulsion into water with surfactant or lipid, and emulsifying the mixture to form the final particles in water.
• the resulting particle structure will have one or more particles made with polymer plus bioactive agent at the center, surrounded by water and surface stabilizer, such as surfactant or lipid, and covered with a pure polymer shell. Surface stabilizer and water will prevent solvent in the polymer coating from contacting the particles inside the coating and dissolving them.
• active agents with low water solubility can be coated with surface stabilizer in the first emulsion, without polymer coating and without dissolving the bioactive agent in water.
• water, surface stabilizer and active agent have similar volume or in the volume ratio range of (1 to 3):(0.2 to about 2):1, respectively.
• water is used, not for dissolving the active agent, but rather for protecting the bioactive agent with help of surface stabilizer.
• the double and triple emulsions are prepared as described above. This method can provide up to 50% drug loading.
• a bioactive agent in the single, double or triple emulsion methods described above, can be conjugated to the polymer molecule as described herein prior to using the polymers to make the particles.
• a bioactive agent can be conjugated to the polymer on the exterior of the particles described herein after production of the particles.
• the emulsifying procedure consists of dissolving polymer with the solvent, mixing with bioactive agent molecule(s), putting into water, and then stirring with a mixer and/or ultra-sonicator.
• Particle size can be controlled by controlling stir speed and/or the concentration of polymer, bioactive agent(s), and surface stabilizer.
• Coating thickness can be controlled by adjusting the ratio of the second to the third emulsion.
• Suitable emulsion stabilizers may include nonionic surface active agents, such as mannide monooleate, dextran 70,000, polyoxyethylene ethers, polyglycol ethers, and the like, all readily commercially available from, e.g., Sigma Chemical Co., St. Louis, Mo.
• the surface active agent will be present at a concentration of about 0.3% to about 10%, preferably about 0.5% to about 8%, and more preferably about 1% to about 5%.
• Rate of release of the at least one bioactive agent from the invention compositions can be controlled by adjusting the coating thickness, particle size, structure, and density of the coating. Density of the coating can be adjusted by adjusting loading of the bioactive agent conjugated to the coating. For example, when the coating contains no bioactive agent, the polymer coating is densest, and a bioactive agent from the interior of the particle elutes through the coating most slowly. By contrast, when a bioactive agent is loaded into (i.e. is mixed or "matrixed” with), or alternatively is conjugated to, polymer in the coating, the coating becomes porous once the bioactive agent has become free of polymer and has eluted out, starting from the outer surface of the coating.
• bioactive agent at the center of the particle can elute at an increased rate.
• the higher the bioactive agent loading in the coating the lower the density of the coating layer and the higher the elution rate.
• the loading of bioactive agent in the coating can be lower or higher than that in the interior of the particles beneath the exterior coating. Release rate of bioactive agent(s) from the particles can also be controlled by mixing particles with different release rates prepared as described above.
• the particles can be made into nanoparticles having an average diameter of about 20 nm to about 200 nm for delivery to the circulation.
• the nanoparticles can be made by the single emulsion method with the active agent dispersed therein, i.e., mixed into the emulsion or conjugated to polymer as described herein.
• the nanoparticles can also be provided as a micellar composition containing the polymers described herein, such as PEA and PEUR with the bioactive agents conjugated thereto.
• the micelles are formed in water, water soluble bioactive agents can be loaded into the micelles at the same time without solvent.
• the biodegradable micelles are formed of a hydrophobic polymer chain conjugated to a water soluble polymer chain.
• the outer portion of the micelle mainly consists of the water soluble ionized or polar section of the polymer, the hydrophobic section of the polymer mainly partitions to the interior of the micelles and holds the polymer molecules together.
• the biodegradable hydrophobic section of the polymer used to make micelles is made of PEEA, PEEUR or PEEU polymers, as described herein.
• the water soluble section of the polymer comprises repeating alternating units of i) polyethylene glycol having a Mw of at least 200 and less than, and b) at least one ionizable or polar amino acid, wherein the repeating alternating units have substantially similar molecular weights and wherein the Mw of the polymer is in the range from about 1 OkD to about 30OkD.
• the repeating alternating units may have substantially similar molecular weights in the range from about 300Da to about 700Da.
• at least one of the amino acid units is an ionizable or polar amino acid selected from serine, glutamic acid, aspartic acid, lysine and arginine.
• the units of ionizable amino acids comprise at least one block of ionizable poly(amino acids), such as glutamate or aspartate, can be included in the polymer.
• the invention micellar composition may further comprise a pharmaceutically acceptable aqueous media with a pH value at which at least a portion of the ionizable amino acids in the water soluble sections of the polymer are ionized.
• the molecular weight of the complete water soluble section of the polymer is in the range from about 5kDa to about 10OkDa.
• the micelles can be lyophilized for storage and shipping and reconstituted in the above-described aqueous media. However, it is not recommended to lyophilize micelles containing certain bioactive agents, such as certain proteins, that would be denatured by the lyophilization process.
• Particle size can be determined by, e.g., dynamic light scattering, using for example, a spectrometer incorporating a helium-neon laser. Generally, particle size is determined at room temperature and involves multiple analyses of the sample in question (e.g., 5-10 times) to yield an average value for the particle diameter. Particle size is also readily determined using scanning electron microscopy (SEM). In order to do so, dry particles are sputter-coated with a gold/palladium mixture to a thickness of approximately 100 Angstroms, and then examined using a scanning electron microscope.
• SEM scanning electron microscopy
• the polymer either in the form of particles or not, can be covalently attached directly to the bioactive agent, rather than incorporating bioactive agent therein ("loading) without chemical attachment, using any of several methods well known in the art and as described hereinbelow.
• the bioactive agent content is generally in an amount that represents approximately 0.1% to about 40% (w/w) bioactive agent to polymer, more preferably about 1% to about 25% (w/w) bioactive agent, and even more preferably about 2% to about 20% (w/w) bioactive agent.
• the percentage of bioactive agent will depend on the desired dose and the condition being treated, as discussed in more detail below.
• Bioactive agents for dispersion into and release from the invention biodegradable polymer compositions also include anti-proliferants, rapamycin and any of its analogs or derivatives, paclitaxel or any of its taxene analogs or derivatives, everolimus, Sirolimus, Tacrolimus, or any of its -limus named family of drugs, and statins such as simvastatin, atorvastatin, fluvastatin, pravastatin, lovastatin, rosuvastatin, geldanamycins, such as 17AAG (17-allylamino-17-demethoxygeldanamycin); Epothilone D and other epothilones, 17- dimethylammoemylamino-17-demethoxy-geldanamycin and other polyketide inhibitors of heat shock protein 90 (Hsp90), Cilostazol, and the like.
• statins such as simvastatin, atorvastatin, fluvastatin, pravastat
• Additional bioactive agents contemplated for dispersion in the polymers used in the invention OEG-based polymer compositions include agents that, when freed or eluted from the polymer particles during their degradation, promote endogenous production of a therapeutic natural wound healing agent, such as nitric oxide, which is endogenously produced by endothelial cells.
• a therapeutic natural wound healing agent such as nitric oxide
• the bioactive agents released from the polymers during degradation may be directly active in promoting natural wound healing processes by endothelial cells.
• bioactive agents can be any agent that donates, transfers, or releases nitric oxide, elevates endogenous levels of nitric oxide, stimulates endogenous synthesis of nitric oxide, or serves as a substrate for nitric oxide synthase or that inhibits proliferation of smooth muscle cells.
• Such agents include, for example, aminoxyls, furoxans, nitrosothiols, nitrates and anthocyanins; nucleosides such as adenosine and nucleotides such as adenosine diphosphate (ADP) and adenosine triphosphate (ATP); neurotransmitter/neuromodulators such as acetylcholine and 5-hydroxytryptamine (serotonin/5-HT); histamine and catecholamines such as adrenalin and noradrenalin; lipid molecules such as sphingosine-1- phosphate and lysophosphatidic acid; amino acids such as arginine and lysine; peptides such as the bradykinins, substance P and calcium gene-related peptide (CGRP), and proteins such as insulin, vascular endothelial growth factor (VEGF), and thrombin.
• nucleosides such as adenosine and nucleot
• bioactive agents such as targeting antibodies, polypeptides (e.g., antigens) and drugs, and the like
• Bioactive agents such as targeting antibodies, polypeptides (e.g., antigens) and drugs, and the like, can be covalently conjugated to the surface of the polymer particles.
• coating molecules such as polyethylene glycol (PEG) as a ligand for attachment of antibodies or polypeptides or phosphatidylcholine (PC) as a means of blocking attachment sites on the surface of the particles to prevent the particles from sticking to non-target biological molecules and surfaces in the patient may also be surface-conjugated.
• PEG polyethylene glycol
• PC phosphatidylcholine
• small proteinaceous motifs such as the B domain of bacterial Protein A and the functionally equivalent region of Protein G are known to bind to, and thereby capture, antibody molecules by the Fc region.
• proteinaceous motifs can be attached to the polymers, especially to the surface of the polymer particles.
• Such molecules will act, for example, as ligands to attach antibodies for use as targeting ligands or to capture antibodies to hold precursor cells or capture cells out of the patient's blood stream. Therefore, the antibody types that can be attached to polymer coatings using a Protein A or Protein G functional region are those that contain an Fc region.
• the capture antibodies will in turn bind to and hold precursor cells, such as progenitor cells, near the polymer surface while the precursor cells, which are preferably bathed in a growth medium within the polymer, secrete various factors and interact with other cells of the subject.
• precursor cells such as progenitor cells
• the precursor cells which are preferably bathed in a growth medium within the polymer, secrete various factors and interact with other cells of the subject.
• one or more bioactive agents dispersed in the polymer particles such as the bradykinins, may activate the precursor cells.
• bioactive agents for attaching precursor cells or for capturing progenitor endothelial cells (PECs) from the subject's blood are monoclonal antibodies directed against a known precursor cell surface marker.
• monoclonal antibodies directed against a known precursor cell surface marker For example, complementary determinants (CDs) that have been reported to decorate the surface of endothelial cells include CD31, CD34, CD102, CD105, CD106, CD109, CDwl30, CD141, CD142, CD143, CD 144, CDwI 45, CD 146, CD 147, and CD 166.
• CD31, CD34, CD102, CD105, CD106, CD109, CDwl30, CD141, CD142, CD143, CD 144, CDwI 45, CD 146, CD 147, and CD 166 CD31, CD34, CD102, CD105, CD106, CD109, CDwl30, CD141, CD142, CD143, CD 144, CDwI 45, CD 146, CD 147, and CD 166
• CDs 106, 142 and 144 have been reported to mark mature endothelial cells with some specificity.
• CD34 is presently known to be specific for progenitor endothelial cells and therefore is currently preferred for capturing progenitor endothelial cells out of blood in the site into which the polymer particles are implanted for local delivery of the active agents.
• antibodies include single-chain antibodies, chimeric antibodies, monoclonal antibodies, polyclonal antibodies, antibody fragments, Fab fragments, IgA, IgG, IgM, IgD, IgE and humanized antibodies.
• bioactive agents and small molecule drugs will be particularly effective for dispersion within the invention polymer particle compositions, whether sized to form a time release biodegradable polymer depot for local delivery of the bioactive agents, or sized for entry into systemic circulation, as described herein.
• the bioactive agents that are dispersed in the polymer particles used in the invention compositions and methods of treatment will be selected for their suitable therapeutic or palliative effect in treatment of a disease of interest, or symptoms thereof.
• the suitable bioactive agents are not limited to, but include, various classes of compounds that facilitate or contribute to wound healing when presented in a time-release fashion.
• Such bioactive agents include wound-healing cells, including certain precursor cells, which can be protected and delivered by the biodegradable polymer particles in the invention compositions.
• wound healing cells include, for example, pericytes and endothelial cells, as well as inflammatory healing cells.
• the polymer particles used in the invention compositions and methods of treatment can include ligands for such cells, such as antibodies and smaller molecule ligands, that specifically bind to "cellular adhesion molecules" (CAMs).
• CAMs cellular adhesion molecules
• Exemplary ligands for wound healing cells include those that specifically bind to Intercellular adhesion molecules (ICAMs), such as ICAM-I (CD54 antigen); ICAM-2 (CD 102 antigen); ICAM-3 (CD50 antigen); ICAM-4 (CD242 antigen); and ICAM-5; Vascular cell adhesion molecules (VCAMs), such as VCAM-I (CD106 antigen)]; Neural cell adhesion molecules (NCAMs) 3 such as NCAM-I (CD56 antigen); or NCAM-2; Platelet endothelial cell adhesion molecules PECAMs, such as PECAM-I (CD31 antigen); Leukocyte-endothelial cell adhesion molecules (ELAMs), such as LECAM-I; or LECAM-2 (CD62E antigen), and the like.
• ICAMs Intercellular adhesion molecules
• ICAM-I CD54 antigen
• ICAM-2 CD 102 antigen
• ICAM-3 CD50 antigen
• ICAM-4 CD242 antigen
• ICAM-5
• the suitable bioactive agents include extra cellular matrix proteins, macromolecules that can be dispersed into the polymer particles used in the invention compositions, e.g., attached either covalently or non-covalently.
• useful extra-cellular matrix proteins include, for example, glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., collagen; elastin; fibronectins and laminin).
• Bio-mimics of extra-cellular proteins can also be used. These are usually non- human, but biocompatible, glycoproteins, such as alginates and chitin derivatives. Wound healing peptides that are specific fragments of such extra-cellular matrix proteins and/or their bio-mimics can also be used as the bioactive agent.
• Proteinaceous growth factors are an additional category of bioactive agents suitable for dispersion in the polymer particles used in the invention compositions and methods of treatment described herein. Such bioactive agents are effective in promoting wound healing and other disease states as is known in the art.
• bioactive agents are effective in promoting wound healing and other disease states as is known in the art.
• PDGF-BB Platelet Derived Growth Factor-BB
• TNF- ⁇ Tumor Necrosis Factor-alpha
• EGF Epidermal Growth Factor
• KGF Keratinocyte Growth Factor
• Thymosin B4 and, various angiogenic factors such as vascular Endothelial Growth Factors (VEGFs), Fibroblast Growth Factors (FGFs), Tumor Necrosis Factor-beta (TNF -beta), and Insulin-like Growth Factor- 1 (IGF-I).
• VEGFs vascular Endothelial Growth Factors
• FGFs Fibroblast Growth Factors
• expression systems comprising vectors, particularly adenovirus vectors, incorporating genes encoding a variety of biomolecules can be dispersed in the polymer particles for timed release delivery.
• Method of preparing such expression systems and vector are well known in the art.
• proteinaceous growth factors can be dispersed into the invention polymer particles for administration of the growth factors either to a desired body site for local delivery by selection of particles sized to form a polymer depot or systemically by selection of particles of a size that will enter the circulation.
• the growth factors such as VEGFs, PDGFs, FGF, NGF, and evolutionary and functionally related biologies, and angiogenic enzymes, such as thrombin, may also be used as bioactive agents in the invention.
• Organic or inorganic chemical compounds "small molecule drugs” are an additional category of bioactive agents suitable for dispersion in the polymer particles used in the invention compositions and methods of treatment described herein.
• Such drugs include, for example, antimicrobials and anti-inflammatory agents as well as certain healing promoters, such as, for example, vitamin A and synthetic inhibitors of lipid peroxidation.
• antibiotics can be dispersed in the polymer particles used in the invention compositions to indirectly promote natural healing processes by preventing or controlling infection.
• Suitable antibiotics include many classes, such as aminoglycoside antibiotics or quinolones or beta-lactams, such as cefalosporins, e.g., ciprofloxacin, gentamycin, tobramycin, erythromycin, vancomycin, oxacillin, cloxacillin, methicillin, lincomycin, ampicillin, and colistin.
• cefalosporins e.g., ciprofloxacin, gentamycin, tobramycin, erythromycin, vancomycin, oxacillin, cloxacillin, methicillin, lincomycin, ampicillin, and colistin.
• Suitable antibiotics have been described in the literature.
• Suitable antimicrobials include, for example, Adriamycin PFS/RDF® (Pharmacia and Upjohn), Blenoxane® (Bristol-Myers Squibb Oncology/Immunology), Cerubidine® (Bedford), Cosmegen® (Merck), DaunoXome® (NeXstar), Doxil® (Sequus), Doxorubicin Hydrochloride® (Astra), Idamycin® PFS (Pharmacia and Upjohn), Mithracin® (Bayer), Mitamycin® (Bristol-Myers Squibb Oncology/Immunology), Nipen® (SuperGen), Novantrone® (Immunex) and Rubex® (Bristol-Myers Squibb Oncology/Immunology).
• the peptide can be a glycopeptide.
• glycopeptide refers to oligopeptide (e.g. heptapeptide) antibiotics, characterized by a multi-ring peptide core optionally substituted with saccharide groups, such as vancomycin.
• glycopeptides included in this category of antimicrobials may be found in "Glycopeptides Classification, Occurrence, and Discovery," by Raymond C. Rao and Louise W. Crandall, in Bioactive agents and the Pharmaceutical Sciences” Volume 63, edited by Ramakrishnan Nagarajan, published by Marcal Dekker, Inc.). Additional examples of glycopeptides are disclosed in U.S. Patent Nos.
• glycopeptides include those identified as A477, A35512, A40926, A41030, A42867, A47934, A80407, A82846, A83850, A84575, AB-65, Actaplanin, Actinoidin, Ardacin, Avoparcin, Azureomycin, Balhimyein, Chloroorientiein, Chloropolysporin, Decaplanin, N-demethylvancomycin, Eremomycin, Galacardin, Helvecardin, Izupeptin, Kibdelin, LL-AM374, Mannopeptin, MM45289, MM47756, MM47761, MM49721, MM47766, MM55260, MM55266, MM55270, MM56597, MM56598, OA-7653, Orenticin, Parvodicin, Ristocetin, Ristomycin, Synmonicin, Teicoplanin, UK-68597, UD-69542, UK-720
• glycopeptide or "glycopeptide antibiotic” as used herein is also intended to include the general class of glycopeptides disclosed above on which the sugar moiety is absent, i.e. the aglycone series of glycopeptides. For example, removal of the disaccharide moiety appended to the phenol on vancomycin by mild hydrolysis gives vancomycin aglycone.
• glycopeptide antibiotics synthetic derivatives of the general class of glycopeptides disclosed above, included alkylated and acylated derivatives. Additionally, within the scope of this term are glycopeptides that have been further appended with additional saccharide residues, especially aminoglycosides, in a manner similar to vancosamine.
• lipidated glycopeptide refers specifically to those glycopeptide antibiotics that have been synthetically modified to contain a lipid substituent.
• lipid substituent refers to any substituent contains 5 or more carbon atoms, preferably, 10 to 40 carbon atoms.
• the lipid substituent may optionally contain from 1 to 6 heteroatoms selected from halo, oxygen, nitrogen, sulfur, and phosphorous. Lipidated glycopeptide antibiotics are well known in the art. See, for example, in U.S. Patent Nos.
• Anti-inflammatory bioactive agents are also useful for dispersion in polymer particles used in invention compositions and methods.
• such anti-inflammatory bioactive agents include, e.g. analgesics (e.g., NSAIDS and salicyclates), steroids, antirheumatic agents, gastrointestinal agents, gout preparations, hormones (glucocorticoids), nasal preparations, ophthalmic preparations, otic preparations (e.g., antibiotic and steroid combinations), respiratory agents, and skin and mucous membrane agents.
• analgesics e.g., NSAIDS and salicyclates
• steroids e.g., antirheumatic agents
• gastrointestinal agents e.g., g., g., gastrointestinal agents, gout preparations, hormones (glucocorticoids), nasal preparations, ophthalmic preparations, otic preparations (e.g., antibiotic and steroid combinations), respiratory agents, and skin and mucous membrane agents.
• ophthalmic preparations e.
• the anti-inflammatory agent can include dexamethasone, which is chemically designated as (1 l ⁇ , 16I)-9-fluro- 11 , 17,21 -trihydroxy- 16-methylpregna- 1 ,4-diene-3 ,20-dione.
• the anti-inflammatory bioactive agent can be or include sirolimus (rapamycin), which is a triene macrolide antibiotic isolated from Streptomyces hygroscopicus.
• polypeptide bioactive agents included in the invention compositions and methods can also include "peptide mimetics.”
• Such peptide analogs referred to herein as “peptide mimetics” or “peptidomimetics,” are commonly used in the pharmaceutical industry with properties analogous to those of the template peptide (Fauchere, J. (1986) Adv. Bioactive agent Res., 15:29; Veber and Freidinger (1985) TINS, p. 392; and Evans et al. (1987) J. Med. Chem., 30:1229) and are usually developed with the aid of computerized molecular modeling.
• Such peptide mimetics may have significant advantages over natural polypeptide embodiments, including, for example: more economical production, greater chemical stability, enhanced pharmacological properties (half-life, absorption, potency, efficacy, etc.), altered specificity (e.g., a broad-spectrum of biological activities), reduced antigenicity, and others.
• substitution of one or more amino acids within a peptide may be used to generate more stable peptides and peptides resistant to endogenous peptidases.
• the synthetic polypeptides covalently bound to the biodegradable polymer can also be prepared from D-amino acids, referred to as inverso peptides.
• inverso peptides When a peptide is assembled in the opposite direction of the native peptide sequence, it is referred to as a retro peptide, hi general, polypeptides prepared from D-amino acids are very stable to enzymatic hydrolysis.
• compositions to be used in preventing or treating a wide variety of diseases or symptoms thereof can be used to prepare compositions to be used in preventing or treating a wide variety of diseases or symptoms thereof.
• composition can be lyophilized and the dried composition suspended in an appropriate media prior to administration.
• any suitable and effective amount of the at least one active agent can be released with time from the polymer particles (including those in a polymer depot formed in vivo) and will typically depend, e.g., on the specific polymer, type of particle or polymer/bioactive agent linkage, if present. Typically, up to about 100% of the polymer particles can be released from a polymer depot formed in vivo by particles sized to avoid circulation. Specifically, up to about 90%, up to 75%, up to 50%, or up to 25% thereof can be released from the polymer depot. Factors that typically affect the release rate from the polymer are the nature and amount of the polymer/bioactive agent, the types of polymer/bioactive agent linkage, and the nature and amount of additional substances present in the formulation.
• compositions are formulated for subsequent intrapulmonary, gastroenteral, subcutaneous, intramuscular, into the central nervous system, intraperitoneum or intraorgan delivery.
• the compositions will generally include one or more "pharmaceutically acceptable excipients or vehicles" appropriate for oral, mucosal or subcutaneous delivery, such as water, saline, glycerol, polyethylene glycol, hyaluronic acid, ethanol, and the like.
• pharmaceutically acceptable excipients or vehicles appropriate for oral, mucosal or subcutaneous delivery, such as water, saline, glycerol, polyethylene glycol, hyaluronic acid, ethanol, and the like.
• auxiliary substances such as wetting or emulsifying agents, pH buffering substances, flavorings, and the like, may be present in such vehicles.
• excipients such as detergents
• excipients may serve various purposes: as an emulsion stabilizer, modifier of interfacial tension or to increase the load of less soluble drug into particles.
• excipients suitable for use in the invention compositions include polyvinyl alcohol (PVA), TWEEN ® 80, Pluronic F-68, sodium dodecyl sulfate (SDS), Brij ® -35, and N-dodecyl- ⁇ -D-maltoside, octyl- ⁇ -D- glucopyranoside, IGEP AL ® CA-630, N-octanoyl-N-methylglucamine, N-nonanoyl-N- methylglucamine, N-decanoyl-N-methylglucamine, Nonidet ® P-40 substitute, Saponin, hexadecylmethyl ammonium bromide, CHAPS 3 EMPIGEN ® BB, and 3- (Dodecyld
• Intranasal and pulmonary formulations will usually include vehicles that neither cause irritation to the nasal mucosa nor significantly disturb ciliary function. Diluents such as water, aqueous saline or other known substances can be employed with the subject invention.
• the intrapulmonary formulations may also contain preservatives such as, but not limited to, chlorobutanol and benzalkonium chloride.
• a surfactant may be present to enhance absorption by the nasal mucosa.
• the vehicle used in the invention compositions may include traditional binders and carriers, such as, cocoa butter (theobroma oil) or other triglycerides, vegetable oils modified by esterification, hydrogenation and/or fractionation, glycerinated gelatin, polyalkaline glycols, mixtures of polyethylene glycols of various molecular weights and fatty acid esters of polyethylene glycol.
• traditional binders and carriers such as, cocoa butter (theobroma oil) or other triglycerides, vegetable oils modified by esterification, hydrogenation and/or fractionation, glycerinated gelatin, polyalkaline glycols, mixtures of polyethylene glycols of various molecular weights and fatty acid esters of polyethylene glycol.
• compositions of the present invention can be incorporated in or may include pessary bases, such as those including mixtures of polyethylene triglycerides, or suspended in oils such as corn oil or sesame oil, optionally containing colloidal silica. See, e.g., Richardson et al., Int. J. Pharm. (1995) 115:9-15.
• OEG-based polymer compositions are also intended for use hi veterinary treatment of a variety of mammalian patients, such as pets (for example, cats, dogs, rabbits, and ferrets), farm animals (for example, swine, horses, mules, dairy and meat cattle) and race horses.
• pets for example, cats, dogs, rabbits, and ferrets
• farm animals for example, swine, horses, mules, dairy and meat cattle
• compositions used in the invention methods optionally may comprise an "effective amount" of the bioactive agent(s) of interest dispersed in the invention OEG-based PE PEEA, PEEUR or PEEU polymer. That is, an amount of a bioactive agent may be included in the compositions that will cause the subject to produce a sufficient therapeutic or palliative response in order to prevent, reduce or eliminate symptoms.
• an amount of a bioactive agent may be included in the compositions that will cause the subject to produce a sufficient therapeutic or palliative response in order to prevent, reduce or eliminate symptoms.
• the exact amount necessary will vary, depending on the subject being treated; the age and general condition of the subject to be treated; the capacity of the subject's immune system, the degree of treatment desired; the severity of the condition being treated; the particular bioactive agent selected, and the mode of administration of the composition, among other factors.
• An appropriate effective amount can be readily determined by one of skill in the art.
• an effective amount will fall in a relatively broad range that can be determined through routine trials.
• an effective amount will typically range from about 1 ⁇ g to about 100 mg, for example from about 5 ⁇ g to about 1 mg, or about 10 ⁇ g to about 500 ⁇ g of the active agent delivered per dose.
• the invention OEG-based polymer compositions are administered orally, mucosally, or by subcutaneously or intramuscular injection, and the like, using standard techniques. See, e.g., Remington: The Science and Practice of Pharmacy, supra, for mucosal delivery techniques, including intranasal, pulmonary, vaginal and rectal techniques, as well as European Publication No. 517,565 and Ilium et al., J. Controlled ReI. (1994) 29:133-141, for techniques of intranasal administration.
• Dosage treatment may be a single dose of the invention OEG-based polymer composition, or a multiple dose schedule as is known in the art.
• the dosage regimen at least in part, will also be determined by the need of the subject and be dependent on the judgment of the practitioner.
• the polymer composition is generally administered prior to primary disease manifestation, or symptoms of the disease of interest. If treatment is desired, e.g., the reduction of symptoms or recurrences, the polymer compositions are generally administered subsequent to primary disease manifestation.
• the formulations can be tested in vivo in a number of animal models developed for the study of oral subcutaneous or mucosal delivery.
• the conscious sheep model is an art-recognized model for testing nasal delivery of substances See, e.g., Longenecker et al., J Pharm. ScI (1987) 76:351-355 and Ilium et al., J Controlled ReI. (1994) 29:133-141.
• the polymer composition generally in powdered, lyophilized form, is blown into the nasal cavity. Blood samples can be assayed for active agent using standard techniques, as known in the art.
• Ia di-p-Nitrophenyl Adipate (NA)
• x 4
• Ib di-p-Nitrophenyl Sebacate (NS)
• x 8
• Ic di-p-Nitrophenyl Fumarate (NF)
• AP3EG and SP3EG achieved the highest M n , M w and reduced viscosity r ⁇ red.
• the synthesized PEEAs had a lower T g than the corresponding saturated or unsaturated PEAs containing the residue of aliphatic diol (Katsasava, R. et al. JPolym Sci Pol Chem (1999) 37(4):391-407 and Guo et al, supra).
• an increase in the number of ether bonds led to a corresponding reduction in T g. and it appeared more pronounced in the saturated PEEA series than in unsaturated PEEAs.
• the lower Tg of the PEEAs was attributed to the presence of ether bonds, causing increased chain flexibility and promoting chain segmental movement.
• PEEURs To illustrate synthesis of the invention PEEURs, the following monomers - active bis-p-nitrophenyl carbonates containing ether blocks of various lengths—were synthesized as described in Example 2 herein. Individual ether diols, di-, tri-, tetra-ethyleneglycols, are commercially available and suitable for this task. Active bis-p-nitrophenyl carbonates were synthesized according to general scheme (VII)
• Weight average molecular weights of the synthesized PEEURs ranged within 31,400 - 51,000 g/mol, as estimated by GPC, (DMF, PMMA), with glass transition temperature in the range of 12-39°C.
• Lipase catalyzed biodegradation was conducted on LlEG based PEEURs. Results are illustrated in Figs. 3A-C, in which the data show that obtained PEEURs were not subjected to chemical hydrolysis in phosphate buffer. By contrast, rates of lipase catalyzed biodegradation were high and not dependent on the length of OEG fragment in R 6 of formulas V-VI.
• L-Phenylalanine (L-Phe), p-toluenesulfonic acid monohydrate (TosOH.H 2 O), sebacoyl chloride, adipoyl chloride, fumaryl chloride, di-ethylene glycol, tri-ethylene glycol and tetra-ethylene glycol (Alfa Aesar, Ward Hill, MA), and p-nitrophenol (J. T. Baker, Phillipsburg, NJ) were used without further purification. Triethylamine (Fisher Scientific, Fairlawn, NJ) was dried by refluxing with calcium hydride, and then distilled.
• N 5 N- Dimethylformamide (DMF) (Aldrich Chemical, Milwaukee, WI) was dried over calcium hydride and distilled.
• Other solvents such as toluene, trifluoroethanol (TFE), tetrahydrofuran (THF), ethyl acetate, acetone, acetonitrile, N,N-dimethylacetamide (DMA), and dimethyl sulfoxide (DMSO) were purchased from VWR Scientific (West Chester, PA) and were purified by standard methods before use.
• Unsaturated PEEA reaction mixtures (FP2EG9, FP3EG and FP4EG), were diluted with acetone to precipitate the product. The polymer was then washed by acetone twice, filtered and finally dried in vacuo for 48 hr.
• Saturated PEEAs were precipitated out in chilled ethyl acetate, products were filtered and further purified in a Soxhlet apparatus by circulating ethyl acetate for 48 h, and dried in vacuo for 48 hr.
• PEEA films were cast from 10% (wt/v) chloroform solution onto Teflon Petri dishes and allowed solvent to evaporate completely at room temperature. The films were further dried in vacuo at room temperature overnight and finally punched into small disc with diameter 12.5 mm.
• W 0 is the original weight of the dry PEEA film sample before immersion
• W t is the dry PEEA film sample weight after incubation for t hrs (with or without enzyme). The weight loss average of three specimens was recorded.
• the molecular weight changes of the PEEA polymers were also monitored by GPC.
• the surface hydrophilicity of the PEEA films was determined by using a MASS Contact Angle Analyzer in a conditioning room maintained at 65% relative humidity and 21 0 C. Distilled water was used as the spreading liquid and the contact angle at five randomly chosen surface areas of each PEEA film was measured. Two PEEA films of each sample type were tested.
• FIG. 2 The effect of on biodegradability of different length of diacid monomer la-b in the invention OEG-based PEEAs is shown in Fig. 2.
• the data summarized therein indicates that the tendency of AP3EG (derived from monomer Ia: di-p-nitrophenyl adipate with 4 methylene groups) to undergo ⁇ -chymotrypsin catalyzed hydrolysis is lower than that of SP3EG (derived from monomer Ib: di-p-nitrophenyl sebacate with 8 methylene groups).
• SP3EG In a 0.10 mg/mL ⁇ -chymotrypsin solution, SP3EG also showed biodegradation kinetics close to zero-order, and an even faster rate of biodegradation than that of AP3EG , 81% vs 56% weight loss within 24 hrs. This result may be attributed to the more hydrophobic PEEA, such as SP3EG, having a greater affinity for ⁇ -chymotrypsin and hence a higher rate of enzymatic hydrolysis than AP3EG.
• OEG-based PEEAs also showed much higher rates of ⁇ -chymotrypsin catalyzed biodegradation than similarly structured PEAs derived from linear aliphatic saturated and unsaturated diols. For example, within 24 hrs, weight loss for SP3EG was 81.3%, while weight loss for SPBU (from 2-butene-l,4-diol) was 13.8% and for SPB (derived from 1,4-butanediol) was 6.4% only. Therefore, incorporation of ether linkages into the backbones of OEG-based PEEA enhances enzymatic biodegradation as compared with that of similarly structured PEAs having aliphatic backbone segments (i.e. derived from aliphatic diols). Table 2
• the PEEA polymer films in the incubation media were also measured by GPC to study their biodegradation (Table 2). Although the weight loss showed significant biodegradation of AP3EG (34.9%) and SP3EG (64.8%) samples in 0.1 mg/mL ⁇ -chymotrypsin solution for 18 hrs, the GPC data showed very little change in molecular weight or molecular weight distribution, and proportional results occurred in lower (0.05 mg/mL, less weight loss), higher (0.20 mg/mL, more weight loss) ⁇ -chymotrypsin concentration and in PBS buffer (almost no weight loss).
• PEEURs saturated OEG-based PEURs
• PEEURs were soluble in DMF, chloroform, and THF.
• the leucine- based polymers were additionally soluble in ethanol.

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