WO2012169973A1 - Nanoparticule à cœur-écorce - Google Patents

Nanoparticule à cœur-écorce Download PDF

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Publication number
WO2012169973A1
WO2012169973A1 PCT/SG2012/000210 SG2012000210W WO2012169973A1 WO 2012169973 A1 WO2012169973 A1 WO 2012169973A1 SG 2012000210 W SG2012000210 W SG 2012000210W WO 2012169973 A1 WO2012169973 A1 WO 2012169973A1
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core
drug
polymer
nanoparticle
shell
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PCT/SG2012/000210
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English (en)
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Jackie Y Ying
Yong Wang
Nandanan Erathodiyil
Nor Lizawati IBRAHIM
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Agency For Science, Technology And Research
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Publication of WO2012169973A1 publication Critical patent/WO2012169973A1/fr

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K31/00—Medicinal preparations containing organic active ingredients
    • A61K31/70—Carbohydrates; Sugars; Derivatives thereof
    • A61K31/7028—Compounds having saccharide radicals attached to non-saccharide compounds by glycosidic linkages
    • A61K31/7034—Compounds having saccharide radicals attached to non-saccharide compounds by glycosidic linkages attached to a carbocyclic compound, e.g. phloridzin
    • A61K31/704—Compounds having saccharide radicals attached to non-saccharide compounds by glycosidic linkages attached to a carbocyclic compound, e.g. phloridzin attached to a condensed carbocyclic ring system, e.g. sennosides, thiocolchicosides, escin, daunorubicin
    • 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
    • A61K47/50—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/56—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an organic macromolecular compound, e.g. an oligomeric, polymeric or dendrimeric molecule
    • A61K47/58—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an organic macromolecular compound, e.g. an oligomeric, polymeric or dendrimeric molecule obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. poly[meth]acrylate, polyacrylamide, polystyrene, polyvinylpyrrolidone, polyvinylalcohol or polystyrene sulfonic acid resin
    • 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
    • A61K47/50—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/69—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit
    • A61K47/6921—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere
    • A61K47/6923—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being an inorganic particle, e.g. ceramic particles, silica particles, ferrite or synsorb
    • 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
    • A61K47/50—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/69—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit
    • A61K47/6921—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere
    • A61K47/6925—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 the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a microcapsule, nanocapsule, microbubble or nanobubble
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00—Preparations for testing in vivo
    • A61K49/06—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations
    • A61K49/18—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes
    • A61K49/1818—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes particles, e.g. uncoated or non-functionalised microparticles or nanoparticles
    • A61K49/1821—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes particles, e.g. uncoated or non-functionalised microparticles or nanoparticles coated or functionalised microparticles or nanoparticles
    • A61K49/1824—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes particles, e.g. uncoated or non-functionalised microparticles or nanoparticles coated or functionalised microparticles or nanoparticles coated or functionalised nanoparticles
    • A61K49/1827—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes particles, e.g. uncoated or non-functionalised microparticles or nanoparticles coated or functionalised microparticles or nanoparticles coated or functionalised nanoparticles having a (super)(para)magnetic core, being a solid MRI-active material, e.g. magnetite, or composed of a plurality of MRI-active, organic agents, e.g. Gd-chelates, or nuclei, e.g. Eu3+, encapsulated or entrapped in the core of the coated or functionalised nanoparticle
    • A61K49/1851—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes particles, e.g. uncoated or non-functionalised microparticles or nanoparticles coated or functionalised microparticles or nanoparticles coated or functionalised nanoparticles having a (super)(para)magnetic core, being a solid MRI-active material, e.g. magnetite, or composed of a plurality of MRI-active, organic agents, e.g. Gd-chelates, or nuclei, e.g. Eu3+, encapsulated or entrapped in the core of the coated or functionalised nanoparticle having a (super)(para)magnetic core coated or functionalised with an organic macromolecular compound, i.e. oligomeric, polymeric, dendrimeric organic molecule
    • A61K49/1854—Nuclear magnetic resonance [NMR] contrast preparations; Magnetic resonance imaging [MRI] contrast preparations characterised by a special physical form, e.g. emulsions, microcapsules, liposomes particles, e.g. uncoated or non-functionalised microparticles or nanoparticles coated or functionalised microparticles or nanoparticles coated or functionalised nanoparticles having a (super)(para)magnetic core, being a solid MRI-active material, e.g. magnetite, or composed of a plurality of MRI-active, organic agents, e.g. Gd-chelates, or nuclei, e.g. Eu3+, encapsulated or entrapped in the core of the coated or functionalised nanoparticle having a (super)(para)magnetic core coated or functionalised with an organic macromolecular compound, i.e. oligomeric, polymeric, dendrimeric organic molecule the organic macromolecular compound being obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. poly(meth)acrylate, polyacrylamide, polyvinylpyrrolidone, polyvinylalcohol
    • 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
    • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
    • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
    • A61K9/51—Nanocapsules; Nanoparticles
    • A61K9/5107—Excipients; Inactive ingredients
    • A61K9/5115—Inorganic compounds
    • 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
    • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
    • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
    • A61K9/51—Nanocapsules; Nanoparticles
    • A61K9/5107—Excipients; Inactive ingredients
    • A61K9/513—Organic macromolecular compounds; Dendrimers
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y5/00—Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery

Definitions

  • the present invention generally relates to a core- shell nanoparticle for drug delivery.
  • the present invention also relates to a process for forming a core-shell nanoparticle for drug delivery.
  • nanotechnology is strongly expressed in areas of medicine, especially drug carriers.
  • drug carriers One of the main uses of such carriers is in the treatment of cancer.
  • chemotherapeutic methods distribute their side effects throughout a body, affecting both targeted cancer and normal cells.
  • these carriers are less than lOOnm, and possess the ability to deliver selected drugs to disease sites by preferentially accumulating in tumors .
  • liposomes are vesicles with a core/shell type structure containing a single or multiple bilayered membrane structure of lipids.
  • albumin is used as a therapeutic carrier for the delivery of hydrophobic chemotherapeutics .
  • Dendrimers are well-defined and regularly-branched macromolecules generally synthesized from elements like sugars, nucleotides and amino acids.
  • Metallic nanoparticles commonly developed from inert metals like gold or titanium, are usually physically in the form of nanoshells.
  • Molecular targeted nanoparticles are based on the functionalization of the surfaces of these nanoparticles with ligands that may bind to tumor-specific surface markers.
  • vector surfaces have been functionalized with targeting ligands complementary to specific or over-expressed -receptors on cancer cells; at a macroscopic level, for instance, by means of an external magnetic field (e.g. in magnetic resonance imaging, MRI ) , and based on the association of a drug/magnetic nanoparticle combination.
  • the magnetic nanoparticles commonly used are based on non-toxic iron oxides.
  • Liposomes, emulsions and micelles have been used in incorporating both a therapeutic drug and an imaging probe.
  • the drug and imaging probe are contained physically. This may lead to a rapid release of the contained entities when introduced into a host and lead to instability of the nanoparticle-carrier and/or incongruence in the bio-distributions of the drug and imaging probe.
  • a core- shell nanoparticle for drug delivery comprising a polymeric shell encapsulating a core comprising a drug and an imaging agent .
  • the drug and imaging agent may be loaded within the core of the polymeric nanoparticle via chemical binding.
  • the drug and imaging agent may be loaded within the core of the polymeric nanoparticle via chemical binding.
  • the presence of the polymeric shell may protect the core contents from early and undesired release in the body.
  • the monomers making up the polymer may be tailored to protect the contents of the core from first pass metabolism or the RES as well as present functional groups for conjugating or binding with the drug and/or imaging agent.
  • the hydrophilic monomer present in the polymeric shell may protect the core contents from interaction with protein or other components in the blood and entrapment by the RES.
  • the presence of the polymeric shell may aid in prolonging the lifetime of the core-shell nanoparticles when circulating in the blood so that the core-shell nanoparticles are able to reach the target site such as tumour tissue.
  • the monomer and/or drug may contain a pH-sensitive linking group.
  • the pH-sensitive linking group may aid in delivering the core-shell nanoparticle to a targeted site such as a tumour. Since tumour tissues normally have a weak acidic environment, the presence of the pH-sensitive linking group may aid in the faster release of the drug in the weak acidic environment.
  • the core-shell nanoparticle may be stable at room temperature to moderately high temperature (such as from 20°C to 45°C) for months.
  • the core-shell nanoparticle may have strong passive targeting ability as a result of their stable and well-protected structure.
  • the core-shell nanoparticle may be capable of coordinated movement in vitro as well as in vivo. Due to the protection provided by the polymeric shell, the core-shell nanoparticle can circulate in the blood for a longer period of time such that the core-shell nanoparticle can- send the drug and imaging agent to a target site (such as tumour tissues) more efficiently as compared to prior art drug carriers.
  • a high loading of drug and/or imaging agent may be achieved in the core.
  • the drug and imaging agent such as a magnetic nanoparticle in the core
  • real-time monitoring of the therapeutic effect and magnetically guided targeting may be enabled.
  • the release of the core contents can be coordinated, giving rise to substantially similar biodistribution of the core contents. Accordingly, synergistic functions of the drug and imaging agent at the therapeutic site may be attainable.
  • a process for forming a . core-shell nanoparticle for drug delivery comprising the steps of: (a) conjugating a drug to a polymer comprising a hydrophilic monomer and an aromatic acid monomer; and (b) introducing an imaging agent to said conjugated drug-polymer under conditions to thereby form said core-shell nanoparticle having said drug and imaging agent in the core.
  • the process may optionally exclude physical methods of entrapping or encapsulating the drug and imaging agent togethe .
  • the process may allow for chemical binding of the drug and imaging agent to the polymer during formation of the core-shell nanoparticle.
  • the nanoparticle may be stable and may release the drug and imaging agent in a synergistic manner with substantially similar biodistribution.
  • conjugate is to be interpreted broadly to refer to the entity formed as a result of covalent attachment of a molecule, for example, a drug, to a corresponding monomeric molecule that has functional groups that can bind with the drug.
  • the formed entity can be termed as “conjugated drug-polymer” or “conjugated drug- monomer” (as appropriate) or variations thereof.
  • imaging agent is to be interpreted broadly to refer to any substance designed to target a physiological function in a subject in vivo or sample in vitro and which can be detected upon administration to the subject or test sample.
  • nano-sized is to be interpreted broadly to define a size range which is less than about lOOOnm, particularly less than about 200 nm, or more particularly between about 1 nm to about 100 nm.
  • nanoparticle is to be interpreted broadly to refer to a particle which has a dimension in the nano- size range, or less than about lOOOnm, particularly less than about 200 nm, or more particularly between about 1 nm to about 100 nm.
  • the above dimension may refer to the dimension of an equivalent spherical particle.
  • the dimension may refer to the diameter of the nanoparticle (or equivalent spherical particle thereof) .
  • the term "about”, in the context of concentrations of components of the formulations, typically means +/- 5% of the stated value, more typically +/- 4% of the stated value, more typically +/- 3% of the stated value, more typically, +/- 2% of the stated value, even more typically +/- 1% of the stated value,, and even more typically +/- 0..5% of the stated value.
  • the core-shell nanoparticle comprises a polymeric shell encapsulating a core comprising a drug and an imaging agent .
  • the process for forming the core-shell nanoparticle for .drug delivery comprises the steps of (a) conjugating a drug to a polymer comprising a hydrophilic monomer and an aromatic acid monomer; and (b) introducing an imaging agent to said conjugated drug-polymer under conditions to thereby form said core-shell nanoparticle having said drug and imaging agent in the core.
  • the polymeric shell may comprise a polymer.
  • the polymer may comprise a hydrophilic monomer.
  • the polymer may comprise an aromatic acid monomer.
  • the polymer may comprise an aromatic amide monomer capable of being conjugated to the drug (hereby termed "conjugated drug-monomer") .
  • the hydrophilic monomer may protect the polymeric nanoparticle from entrapment by the RES. Any monomer that confers a hydrophilic property to the resultant polymer may be used.
  • Exemplary hydrophilic monomer may be a monomer based on an alkenyl ether, an allyl ether, an alkylene glycol and/or a phenyl ether.
  • the hydrophilic monomer ay be selected from the group consisting of 4-vinylbenzyl methoxy triethylene glycol ether, hydroxypolyethoxy allyl ether, ethylene glycol, ethylene glycol linked to a styrene-containing monomer and allyl phenyl ether.
  • the aromatic acid monomer may , be any aromatic acid- containing monomer that is capable of conjugating with the drug as well as bind with the imaging agent.
  • the polymeric shell may comprise an aromatic acid monomer selected to chemically bond with the drug in said core.
  • the aromatic acid monomer may be benzoic acid such as 4-vinyl benzoic acid.
  • the polymer may be a di-block polymer comprising monomers of the hydrophilic monomer and the aromatic acid monomer.
  • the polymer may be a di-block polymer comprised of the alkenyl ether-based monomer (such as 4-vinylbenzyl methoxy triethylene glycol ether) and the aromatic acid monomer (such as 4-vinyl benzoic acid).
  • the mol% of the hydrophilic monomer in the resultant polymer may be in the range of about 60 to about 70 mol.% while the mol% of the aromatic acid monomer accounts for the remaining 30 to 40 mol% .
  • the diblock polymer may be synthesized via nitroxide-mediated radical polymerization.
  • the hydrophilic monomer may be added to an initiator in an appropriate solvent to initiate the hydrophilic monomer. Any unreacted monomer may be removed.
  • the obtained polymer (made up of poly (hydrophilic monomer)) in a suitable solvent ' may be used as a macroinitiator to initiate another monomer, such as the aromatic acid monomer, to build the diblock polymer (or the triblock polymer, as will be explained further below) .
  • the conjugated drug-monomer may be any monomer that has an amide group that can conjugate with a drug.
  • An exemplary conjugated drug-monomer is 4-vinylbenzoic amide conjugated with a drug.
  • the monomer may be 4-vinylbenzoic doxorubicin amide.
  • the polymer may be a tri-block polymer comprising the hydrophilic monomer, the aromatic acid monomer and - the conjugated drug-monomer.
  • the polymer may comprise a tri-block polymer comprised of- the alkenyl ether-based monomer (such as 4-vinylbenzyl methoxy triethylene glycol ether) , the aromatic acid monomer (such as 4-vinyl benzoic acid) and the conjugated drug-monomer (such as 4-vinylbenzoic amide conjugated with a drug) .
  • the moll of the hydrophilic monomer in the resultant polymer may be in the range of about 70 to about 90 mol%, the mol% of the aromatic acid monomer may be in the range of about 5 to 25 mol% and the mol% of the conjugated drug-monomer may be in the range of about 3 to about 5 mol%.
  • the di-block polymer may be reacted or polymerized with the conjugated drug-monomer.
  • poly (hydrophilic ether) as mentioned above may be mixed with the aromatic acid monomer and conjugated drug-monomer to form the tri-block polymer.
  • the tri-block polymer may be one which has the drug and the carboxylic acid groups in different portions of the polymer .
  • the drug of the core may be selected to be capable of being chemically bonded to monomers of the polymeric shell.
  • the drug may be a chemotherapeutic drug or an anti-cancer drug.
  • the drug may be an alkylating agent, an antimetabolite, an ⁇ anthracycline, a plant alkaloid, a topoisomerase inhibitor and other antitumor agents. It is to be noted that the choice of drug is not limited as long as it is able to conjugate or bind to one of the monomers in the polymer. It is also to be noted that the person skilled in the art would know what monomer should be used when considering the type of drug to be encapsulated in the core.
  • the drug may comprise moieties selected from the group consisting of amino groups, amine groups, ether groups and carbonyl groups, that can be conjugated via amidation reaction or hydrazine bonding to the monomer.
  • Other anti-cancer drugs can also be used as long as the drug can be conjugated to a monomer.
  • one or more of the amino groups or amine groups or carbonyl groups chemically bonds with the carboxylic acid moiety of the aromatic acid monomer.
  • the alkylating agent may be selected from the group consisting of cyclophosphamide, mechlorethamine , uramustine, melphalan, chlorambucil, ifosfamide, carmustine, lomustine, streptozocin, busulfan, thiotepa, cisplatin, carboplatin, nedaplatin, oxaliplatin, satraplatin, triplatin tetranitrate, procarbazine, altretamine, decarbazine, mitozolomide , temozolomide and analogues thereof.
  • the antimetabolite may be selected from the group consisting of- methotrexate, 5-fluorouracil , 6- mercaptopurine, 6-thioguanine and cytarabine.
  • the anthracycline may be selected from the group consisting of daunorubicin, doxorubicin, epirubicin, idarubicin, valrubicin, mitoxantrone .
  • the ' plant alkaloid may be selected from vincristine, vinblastine, vinorelbine, vindesine, paclitaxel and docetaxel .
  • the topoisomerase inhibitor may be selected from the group consisting of irinotecan, topotecan, amsacrine, etoposide, etoposide phosphate and teniposide. It is to be appreciated that a mixture of two or more of the above drugs can be conjugated to the polymer and hence be encapsulated in the core. In order to conjugate a mixture of drugs, the monomer or monomers should be chosen as appropriate in order to present functional groups or binding groups that can bind with the various types of drugs.
  • the drug may be linked with a pH-sensitive linking group (such as hydrazone or cis-aconityl group) .
  • the pH-sensitive linking group may aid in the release of the drug in an appropriate pH environment.
  • the pH environment may be a weakly acidic environment, which is normally found in tumor tissues.
  • the presence of the pH- sensitive linking group may aid in the release of the drug at a targeted site, such as tumour tissues.
  • the percentage release of the drug from the nanoparticle in the weakly acidic environment may be in the range of about 35% to about 60%.
  • the drug may be conjugated to the polymer by two approaches.
  • the first approach involves conjugation onto the diblock polymer directly by partial reaction of binding groups with the drug via a suitable reaction to obtain a diblock polymer with the drug randomly distributed on the aromatic acid monomer segment.
  • doxorubicin can be conjugated with the diblock polymer directly by partial reaction of carboxylic acid groups with doxorubicin via amidation to obtain a conjugated doxorubicin-diblock polymer in which doxorubicin may be randomly distributed on the aromatic acid monomer segment.
  • Suitable catalyst (s) for catalyzing the amidation reaction between the doxorubicin and diblock polymer may be used.
  • the catalysts may be N, W-dicyclohexylcarbodiimide, N-hydroxysuccinimide and triethylamine.
  • the second approach involves polymerizing the conjugated drug-monomer with either the diblock polymer or a mixture of poly (hydrophilic ether) and aromatic acid monomer to form the tri-block polymer as explained above.
  • the drug is then present in different parts of the triblock polymer.
  • the imaging agent may be selected from the group consisting of metals (such as transition metals), radioactive isotopes and radioopaque agents (e.g., gallium, technetium, indium, strontium, iodine, barium, bromine and phosphorus-containing compounds), radiolucent agents, contrast agents, dyes- (e.g., fluorescent dyes and chromophores ) and enzymes that catalyze a colorimetric or fluorometric reaction.
  • metals such as transition metals
  • radioactive isotopes and radioopaque agents e.g., gallium, technetium, indium, strontium, iodine, barium, bromine and phosphorus-containing compounds
  • radiolucent agents e.g., contrast agents, dyes- (e.g., fluorescent dyes and chromophores ) and enzymes that catalyze a colorimetric or fluorometric reaction.
  • the imaging agent of the core may be selected to be capable of being chemically bonded to monomers of the polymeric shell.
  • the imaging agent may be a MRI imaging agent, such as a magnetic nanoparticle.
  • the magnetic nanoparticle may comprise a transition metal of the Periodic Table of Elements.
  • the transition metal may be selected from the group consisting of cobalt, iron, platinum, gadolinium, manganese and mixtures thereof.
  • the magnetic nanoparticle may be selected from the group consisting of gadolinium (III) chelate, superparamagnetic iron oxide, ultrasmall superparamagnetic iron oxide, superparamagnetic iron platinum, paramagnetic managanese chelate, manganese iron oxide, iron cobalt, iron platinum and cobalt platinum.
  • the polymer may be loaded with the imaging agent such as magnetic nanoparticles via reaction of the magnetic nanoparticles with the carboxylic acid groups on the polymer.
  • the magnetic nanoparticles may be loaded in the polymeric nanoparticle by a -, dialysis procedure.
  • the dialysis procedure may be a three-step procedure.
  • the first dialysis may be carried out to exchange the fatty acid (such as oleic acid) that may be present on the magnetic nanoparticles with an aromatic hydrocarbon (such as toluene) .
  • the second dialysis may be carried out to remove the aromatic hydrocarbon and fatty acid by exchanging with an organosulphur compound (such as dimethyl sulphoxide).
  • the third dialysis may be carried out to remove the organosulphur compound by exchanging with water.
  • the loading of the drug within the core may be in the range selected from the group consisting of about 5 wt% to about 35 wt%, about 5 wt% to about 10 wt%, about 5 wt% to about 15 wt%, about 5 wt% to about 20 wt%, about 5 wt% to about 25 wt%, about 5 wt% to about 30 wt%, about 10. wt% to about 35 wt%, about 15 wt% to about 35 wt%, about 20 wt% to about 35 wt%, about 25 wt% to about 35 wt% and about 30 wt% to about 35 wt%.
  • the drug loading in the core is about 30 wt%. In another polymer, the drug loading in the core is about 8 wt% to about 9 wt% while in another polymer, the drug loading in the core is about 12 wt% to about 13 wt%.
  • the loading of the imaging agent within the core may be in the range selected from the group consisting of about 25 wt% to about 70 wt%, about 25 wt% to about 30 wt%, about 25 wt% to about 35 wt%, about 25 wt% to about 40 wt%, about 25 wt% to about 45 wt%, about 30 wt% to about 50 wt%, 25 wt% to about 55 wt%, 25 wt% to about 60 wt%, 25 wt% to about 65 wt%, about 35 wt% to about 70 wt%, about 40 wt% to about 70wt% and about 45 wt% to about 70wt%, 50 wt% to about 70 wt%, 55 wt% to about 70 wt%, 60 wt% to about 70 wt% and 65 t% to about 70 wt% .
  • the magnetic nanoparticle loading is in the range of about
  • the loaded nanoparticle may have a particle size in the range selected from the group consisting of about 90 nm to about 160 nm, 90 nm to about 100 nm, 90 nm to about 110 nm, 90 nm to about 120 nm, 90 nm to about 130 nm, 90 nm to about 150 nm, 100 nm to about 160 nm, 110 nm to about 160 nm, 120 nm to about 160 nm, 130 nm to about 160 nm, 140 nm to about 160 nm and 150 nm to about 160 nm.
  • the average particle size of the nanoparticle may be about 108 + 1 nm.
  • the average particle size of the nanoparticle may be about 104 + 2 nm while for a third specific polymer the average particle size of the nanoparticle may be about 154 + 2 nm.
  • the polymer may comprise a drug linked with a pH sensitive group.
  • the particle size of the resultant (loaded) nanoparticle formed from this polymer may be in the range of about 550 to about 600 nm. In one embodiment, the average particle size of this nanoparticle may be 574.1 + 3.6 nm.
  • the polydispersity of the polymer may be in the range selected from the group consisting of about 1.0 to about 2.0, about 1.0 to about 1.1, about 1.0 to about 1.2, about 1.0 to about 1.3, about 1.0 to about 1.4, about 1.0 to about 1.5, about 1.0 to about 1.6, about 1.0 to about 1.7, about 1.0 to about 1.8, about 1.0 to about 1.9, about 1.1 to about 2.0, about 1.2 to about 2.0, about 1.3 to about 2.0, about 1.4 to about 2.0, about 1.5 to about 2.0, about 1.6 to about 2.0, about 1.7 to about 2.0, about 1.8 to about 2.0 and about 1.9 to about 2.0.
  • the polydispersity may be about 1.22.
  • the core-shell nanoparticles Due to the narrow polydispersity of the polymer, better biodistribution of the core contents can be achieved so that almost all of the core-shell nanoparticles can reach the target site (such as a tumour tissue) in order to release the core contents in a targeted manner to the desired sites. This may aid in minimizing any side effects. This is in comparison to larger particles that are too big and can get entrapped in some particular organ, such as lung or liver, without reaching the target site.
  • the molecular weight of the polymer may be in the range selected from the group consisting of about 20 kDa to about 200 kDa, about 20 kDa to about 40 kDa, about 20 kDa to about 60 kDa, about 20 kDa to about 80 kDa, about 20 kDa to about 100 kDa, about 20 kDa to about 120 kDa, about 20 kDa to about 140 kDa, about 20 kDa to about 160 kDa, about 20 kDa to about 180 kDa, about 40 kDa to about 200 kDa, about 60 kDa to about 200 kDa, about 80 kDa to about 200 kDa, about 100 kDa to about 200 kDa, about 120 kDa to about 200 kDa, about 140 kDa to about 200 kDa, about 160 kDa to about 200 kDa, about 180 kDa to about 200
  • the molecular weight of a specific polymer may be about 34.1 kDa.
  • the molecular weight of another "specific polymer may be about 29.7 kDa while the molecular weight of a third specific polymer maybe about 67.4 kDa.
  • the number average molecular weight of the polymer may be in the range selected from the group consisting of about 20 kDa to about 200 kDa, about 20 kDa to about 40 kDa, about 20 kDa to about 60 kDa, about 20 kDa to about 80 kDa, about 20 kDa to about 100 kDa, about 20 kDa to about 120 kDa, about 20 kDa to about 140 kDa, about 20 kDa to about 160 kDa, about .
  • the molecular number of a specific polymer may be about 28.0 kDa.
  • the molecular number of another specific polymer may be about 24.0 kDa while the molecular number of a third specific polymer maybe about 37.4 kDa.
  • the nanoparticle may be stable at a temperature of about 20°C to about 45°C for months.
  • the nanoparticle may maintain ' high stability in neutral pH environments and may release completely in weakly acidic environments via hydrolysis in the long term.
  • Fig. 1 (a) is a reaction scheme of the three-step procedure to synthesize the initiator, 2 , 2 , 5-trimethyl-3- ( 1-phenylethoxy ) -4-phenyl-3-azahexane (TPPA) , in Example 1.
  • TPPA 5-trimethyl-3- ( 1-phenylethoxy ) -4-phenyl-3-azahexane
  • Fig. 2 shows the H NMR spectrum of Compound (1) obtained in Step 1 of Example 1.
  • Fig. 3 shows the 1 H NMR spectrum of Compound (2) obtained in Step 2 of Example 1.
  • Fig. ' 4 shows the 1 H NMR spectrum of Compound (3) (i.e. TPPA) obtained in Step 3 of Example 1.
  • Fig. 5 shows the 1 H NMR spectrum of TEGSt obtained in Example 2.
  • Fig. 6 shows the 1 H NMR spectrum of DOXSt obtained in Example 3.
  • Fig. 7 shows the 13 C NMR spectrum of DOXSt obtained in Example 3.
  • Fig. 8 shows a schematic diagram of the arrangement of the monomers of the four polymers A to D synthesized in Example .
  • Fig. 9 shows the ⁇ ⁇ NMR spectra of Polymer A (poly (TEGSt-co-VBA) obtained in Example 4.
  • Fig. 10 shows the 1 H NMR spectra of Polymer B (poly (TEGSt-co-VBA) -DOX) obtained in Example 4.
  • Fig. 11 shows the 1 ⁇ 2 NMR spectra of Polymer C (poly (TEGSt-co-VBA-co-DOXSt ) obtained in Example 4.
  • Fig. 12 shows the 1 H NMR spectra of Polymer D (poly (TEGSt-co-DOXSt-co-VBA) ) obtained in Example 4.
  • Fig. 13 shows the gel permeation chromatography (GPC) curves of Polymers A to D obtained in Example 4.
  • Figs. 16(a), (b) and (c) show the transmission electron microscopy (TEM) images as well as photographs and particle size distributions as measured by DLS of the magnetite nanocube (MN) -loaded Polymers B, C and D (referred to as B-MN, C-MN .and D-MN respectively) obtained in Example 7.
  • TEM transmission electron microscopy
  • Fig. 17 shows the thermal gravimetric analysis (TGA) of B-MN obtained in Example 7.
  • Figs. 18(a), (b) and (c) show graphs of the particle sizes of Polymers B, C and D compared against B-MN, C-MN and D-MN respectively referred to in Example 7.
  • Fig. 19(a) shows the X-ray diffraction (XRD) graph of the magnetite nanoparticles (top curve) as compared with B- MN (bottom curve) obtained in Example 7.
  • Fig. 19(b) shows the fluorescence of HepG2 cells of Example 8 after 15 min of incubation with application of a magnetic field (right) as compared to without application of a magnetic field (left) .
  • Fig. 20 shows the intensity of the toxicity .of Polymers A and B loaded with MNs (i.e. MN-P (TEGSt-co-VBA) and MN-P (TEGSt-co-VBA) -DOX respectively) against polymer concentration referred to in Example 8.
  • MNs i.e. MN-P (TEGSt-co-VBA) and MN-P (TEGSt-co-VBA) -DOX respectively
  • Fig. 21 shows the bio-distributions of doxorubicin and iron in the tumor, heart, kidney, liver, lung and spleen in balb/C mice referred to in Example 9 tracked via red fluorescence and Prussian staining.
  • the fluorescence images are shown in the first and third columns, while the Prussian staining images are shown in the second and fourth columns .
  • tri (ethylene glycol )monomethyl ether > 97%), 4-vinyl benzoic acid (VBA) , N, N' -dicyclohexylcarbodiimide (DCC) , triethylene amine, tert-nitrobutane, isobutyraldehyde, ammonium chloride, zinc powder, bromobenzene, brine, Na 2 S0 4 , NH 4 C1, NH 4 OH, Cu(OAc) 2 , NaHC0 3 , anisole and silica gel used for flash column chromatography were purchased from Merck & Co (New Jersey, United States of America (USA) ) .
  • the initiator, 2 , 2 5-trimethyl-3- ( 1-phenylethoxy) -4- phenyl-3-azahexane (TPPA) , was synthesized via a three-step procedure.
  • the three-step procedure is detailed in the following in accordance with the reaction scheme illustrated in Fig. 1(a).
  • Compound (1) was characterized by 1 H NMR spectroscopy (Bruker AVANCE 400 spectrometer, Bruker, Germany) at 400 MHz using the solvent CDCI 3 to determine the chemical shifts expressed in parts per million ( ⁇ ) values using residual protons in the solvent as the internal standard and the spectrum is shown in Fig. 2. As seen from Fig. 2, a peak from 6.58 ppm to 6.57 ppm represents (d, 1H) , a peak from 3.18 ppm to 3.06 ppm represents (m, 1H) , a peak at 1.42 ppm represents (s, 9H) and a peak from 1.05 to 1.03 represents (d, 6H) .
  • the Grignard reagent was then added dropwise to the mixture and stirred at room temperature overnight.
  • the excess Grignard reagent was quenched via the addition of 10 mL of saturated NH 4 C1 solution at 0°C. 30 mL of water was then added until all the solids were dissolved.
  • the aqueous layer was then extracted with 30 mL of Et 2 0 thrice, washed with 50 mL of brine, dried with Na2 S0 4 , filtered and concentrated to obtain a residue.
  • the residue was then treated with a mixture of 200 mL of methanol, 15 mL of NH 4 OH and Cu(OAc) 2 (0.459 g, 0.23 mmol) to give a pale yellow solution.
  • Compound (2) was characterized by ⁇ ⁇ NMR spectroscopy at 400 MHz using the solvent CDC1 3 to determine ⁇ values and the spectrum is shown in Fig. 3.
  • a peak from 7.70 ppm to 7.33 ppm represents (m, 5H)
  • a peak from 3.68 ppm to 3.61 ppm represents (m, 1H)
  • a peak from 2.13 ppm to 2.07 ppm represents (m, 1H)
  • a peak from 1.46 ppm to 1.32 ppm represents (d, 9H)
  • a peak from 1.11 ppm to 0.92 ppm represents (m, 6H) .
  • a peak from 7.46 ppm to 7.16 ppm represents (m, 10H)
  • a peak from 4.94 ppm to 4.89 ppm represents (qq, 1H)
  • a peak from 4.22 ppm to 4.02 ppm represents (m, 1H)
  • a peak from 3.44 ppm to 3.29 ppm represents (dd, 1H)
  • a peak from 2.37 ppm to 2.30 ppm represents (m, 1H)
  • a peak from 1.64 ppm to 1.63 ppm represents (d, 1H)
  • a peak from 1.561 ppm to 1.54 ppm represents (d, 3H)
  • a peak from 1.321 ppm to 1.31 ppm represents (d, 1H) , peaks at 1.05 ppm
  • a peak at 7.36 ppm represents (d, 2H)
  • a peak at 7.287 ppm represent (d, 2H)
  • a peak at 6.70 ppm represents (dd, 1H)
  • a peak at 5.72 ppm represents (dd, 1H)
  • a peak at 5.21 ppm represents (dd, 1H)
  • a peak at 4.54 ppm represents (s, 2H) .
  • the reaction was allowed to react for another 24 h under argon atmosphere and aluminum foil. Thereafter, the solution was filtered and precipitated in ether to harvest the dark red powder. The crude product was re-dissolved in dichloromethane and filtered to remove the unreacted doxorubicin residue. The solution was evaporated to obtain a red powder, DOXSt, for purification using silica gel column chromatography (100:5 of dichloromethane (DCM) /methanol) .
  • DCM dichloromethane
  • the red powder product was synthesized was characterized by 1 ⁇ 2 NMR spectroscopy at 400 Hz using the solvent d 6 -DMSO to determine ⁇ values, 13 C NMR spectroscopy at 400 Hz using dg-DMSO to determine ⁇ values and time-of- flight mass spectrometry (MS-TOF) using electrospray ionization (ESI) to determine mass-to-charge (m/z) ratio.
  • MS-TOF time-of- flight mass spectrometry
  • ESI electrospray ionization
  • a peak at 7.83 ppm represents (m, 2H)
  • a peak at 7.74 ppm represents (d 2H)
  • a peak at 7.57 ppm represents (m, 1H)
  • a peak at 7.48 ppm represents (dd, 2H)
  • a peak at 6.73 ppm represents (dd, 1H)
  • a peak at 5.88 ppm represents (dd, 1H)
  • a peak at 5.32 ppm represents (dd,lH)
  • a peak at 5.23 ppm represents (t, 1H)
  • a peak at 4.90 ppm represents (t, 1H)
  • a peak at 4.57 ppm represents (s, 2H)
  • a peak at 4.20 ppm represents (m, 2H)
  • a peak at 3.90 ppm represents (s, 3H)
  • a peak at 3.52 ppm represents (m, 1H)
  • a peak at 3.52 ppm represents (m, 1H)
  • the 13 C NMR spectrum is shown in Fig. 7. As seen from Fig. 7, the peak values are 213.0, 185.7, 185.6, 164.9, 159.9, 154.8, 153.2, 138.9, 135.0, 134.4, 133.7, 133.0,
  • polymers A to D were synthesized in this example in accordance with the schematic diagram in Fig. 8. As seen in Fig. 8, the monomers, used were 4-Vinylbenzoic acid (VBA) , TEGSt and DOXSt and the arrangement of the monomers differ in each of polymers A to D.
  • VBA 4-Vinylbenzoic acid
  • TEGSt TEGSt
  • DOXSt DOXSt
  • VBA was used as the monomer for building the block to bind the magnetite nanocubes and to randomly conjugate doxorubicin.
  • TEGSt synthesized from Example 2 was employed in building the hydrophilic segment and protecting against entrapment by the RES.
  • DOXSt synthesized from Example 3 was designed to conjugate doxorubicin.
  • the polymers synthesized were characterized by 1 H NMR spectroscopy and gel permeation chromatography (GPC) .
  • the 1 H NMR spectra of Polymer A (poly (TEGSt-co-VBA) , Polymer B (poly (TEGSt-co-VBA) -DOX) , Polymer C (poly (TEGSt-co-VBA-co- DOXSt) and Polymer D (poly (TEGSt-co-DOXSt-co-VBA) ) are shown in Figs. 9 to 12 respectively.
  • the GPC curves of Polymers A to D are shown in Fig. 13. Further, the loading of each monomer unit into each polymer synthesized is detailed in Table 1 further below.
  • Polymer A made up of the monomers TEGSt and VBA, was synthesized here. This diblock polymer was synthesized via a two-step procedure using a living polymerization reaction, nitroxide-mediated radical polymerization (NMRP) .
  • NMRP nitroxide-mediated radical polymerization
  • TEGSt (1.23 g, 4 mmol) was added into a 10-mL ampule bottle with a stirrer bar and was allowed to dissolve in 2 mL of anisole added with the TPPA obtained from Example 1 (13 mg, 0.043 mmol).
  • the solution in the ampule bottle was degassed by freeze-pump- backfilling with nitrogen for 6 times and sealed with a blow torch. After warming to room temperature, the ampule was placed in a 130°C oil bath and stirred overnight.
  • the TEGSt polymer product obtained ' was then dissolved in 5 ml of anisole and applied as a macroinitiator .
  • the macroinitiator was dissolved in anisole and added to a 10-mL ampule bottle with a stirrer bar. Thereafter, VBA (300 mg, 2 mmol) was added.
  • the solution in the ampule bottle was degassed by freeze-pump- refilling of nitrogen for 6 times and sealed with a blow torch. The ampule was warmed to room temperature, placed in a 130°C bath and stirred overnight.
  • the molar percentages of the two polymer blocks i.e. the TEGSt polymer product and the copolymer product of TEGSt and VBA, were estimated by analyzing the X H NMR spectrum shown in Fig. 9. Specifically, the ratio of the (CH)2-C3 ⁇ 4- peak at ⁇ 4.47 (equivalent to A T EGst/2) which was attributed to TEGSt, was compared with the aromatic peak at ⁇ 6-8 (equivalent to A T EGst + ⁇ ⁇ ⁇ ) which was attributed to the copolymer of TEGSt and VBA, to estimate the molar percentages of the two polymer blocks.
  • the content of TEGSt and VBA calculated from the 1 H NMR spectrum in Fig. 9 was 62 mol% and 38 mol%, respectively. About 96% of the monomers were incorporated into the polymer.
  • the polydispersity for polymer A was 1.22, which was much narrower than that of polymers obtained by other non-living polymerization methods (usually higher than 1.5).
  • the GPC curve in Fig. 13 of the Polymer A synthesized shows a shoulder peak, which is common for the NMRP reaction with high monomer to initiator ratio and high monomer conversion.
  • DOX was , introduced by conjugation onto Polymer A directly by partial reaction of the carboxylic acid groups with DOX via amidation to obtain polymer B, with DOX randomly distributed on the VBA segment as shown in Fig. 8.
  • Conjugation of DOX onto Polymer A, i.e. poly (TEGSt-co-VBA) was synthesized as follows.
  • DOX was introduced by a second method. Specifically, DOX was introduced by polymerizing DOXSt to obtain Polymer C, i.e. poly (TEGSt-co-VBA-co-DOXSt ) , as seen in Fig . 8.
  • VBA 200 mg was added to a 10-mL ampule containing 1 g of poly(TEGSt) in 2mL of anisole and stirred with a magnetic stirrer bar.
  • the ampule was degassed by a freeze- pump-nitrogen gas refilling procedure for 6 times and sealed with a blow torch. After reaction at 130°C overnight, the solution was precipitated twice in hexane . 1 g of dry product, i.e. poly (TEGSt-co-VBA) was obtained.
  • DOXSt was added to a 10-mL ampule containing poly (TEGSt-co-VBA) dissolved in 6 mL of anisole, degassed the same way as described above, and sealed. The system was allowed to react overnight at 130°C. The solution was diluted by DMSO, dialyzed against DMSO for one day and dialyzed against deionized water for another day. The dialysis tubing molecular weight cut-off. (MWCO) ⁇ used was 3500 Da. A product, i.e. poly (TEGSt-co-VBA-co-DOXSt ) , weighing 0.90 g was harvested by freeze drying.
  • poly (TEGSt-co-VBA-co-DOXSt ) weighing 0.90 g was harvested by freeze drying.
  • VBA was initiated successfully as shown in Fig. 11. From Fig. 11, the TEGSt incorporated into Polymer C is 72 mol%, the VBA incorporated was 24.4 mol% and the DOXSt incorporated was 3.6 mol% or 8.7 wt% . This is described in Table 1 further below.
  • DOX was introduced in the same way as for Polymer C, except that Polymer D carried DOXSt and VBA in a reversed manner as compared to Polymer C. As seen in Fig. 8, DOX was introduced by polymerizing DOXSt to obtain Polymer D, i.e. poly (TEGSt-co-DOXSt-co-VBA) .
  • DOXSt 200 mg was added to a 10-mL ampule with 1 g of poly(TEGSt) dissolved in 6 mL of anisole. After degassing with the freeze-pump-nitrogen gas refilling procedure for 6 times as described above and sealing, the reaction was allowed to take place overnight at 130 °C. The product was diluted, dialyzed against DMSO for one day and dialyzed against deionized water for another day. The dialysis tubing MWCO used was 3500 Da. The product was freeze-dried and redissolved in 6 mL of anisole before it was added to a 10-mL ampule. "
  • Polymer D was characterized by 1 H NMR spectroscopy as seen in Fig. 12. Referring, .to Fig. 12 and Table 1 below, the 1 H NMR spectrum showed that there were about 90 mol% of TEGSt, 5 mol% or 12.2 wt% of DOXSt and 5 mol% of VBA in Polymer D. Further, it can be seen from Fig. 12 that the DOXSt loading was much lower than the monomer added at a ratio of TEGSt to DOXSt of 1 g to 0.2 g.
  • Polymer D has a much broader polydispersity of 1.88 than the other three polymers .
  • the MWs of the polymers were determined by GPC (using Waters 2690, Waters Corporation, Massachusetts, USA)- with a differential refractometer detector (Waters 410). 10 mg of polymer was dissolved in 5 mL of THF and filtered. The mobile phase was THF with a flow rate- of 2 mL/min. Weight and number average molecular weights (Mw and Mn) were calculated from a calibration curve using a series of polystyrene standards (Polymer Laboratories, Inc., Massachusetts, USA) with molecular weights ranging from 1,300 to 30,000 Da.
  • the procedure is detailed in the following in accordance with the reaction scheme illustrated in Fig. 1(b). 581 mg (1.0 mmol) doxorubicin was allowed to react with 524.9 mg (5.0 mmol) hydrazine ⁇ 2HCL in 20 ml DMF overnight under protection of aluminum foil. 3 drops of trifluoroacetic acid (TFA) was added as catalyst. Next, DMF was removed by rotavapor and dried further in vacuum. Afterwards, the solid was washed by 10 mL of deionized (DI) water for four times carefully. The residue was dried again by vacuum.
  • DI deionized
  • Doxorubicin linked with hydrazone was conjugated to poly (TEGSt-co-VBA) as follows. 0.52 g of poly (TEGSt-co-VBA) with 56.74 mol% of VBA monomer units (1.44 mmol of VBA monomer units estimated by 1 H NMR) was dissolved in 10 mL of DMF and added with DCC (148.35 mg, 0.72 mmol), NHS (83.3 mg, 0.72 mmol) and 0.5 mL of triethylamine sequentially. Hydrazone linked doxorubicin (454 mg, 0.72 mmol) was added after 4 h and allowed to react overnight. Thereafter, the solution was filtered, dialyzed against DMSO for 2 days and dialyzed against DI water for another 2 days.
  • the percentage release of doxorubicin at different pH values of 4.6 and 7.4 was charted and the graph is shown in Fig. 14.
  • the pH value of 4.6 was achieved using 0.2 M of sodium acetate buffer and the pH value of 7.4 was achieved using phosphate buffered saline (PBS).
  • PBS phosphate buffered saline
  • the particle size of the nanoparticles obtained after dialysis was measured by dynamic light scattering (DLS) using ZetaPALS (from Brookhaven Instruments Corporation, New York, USA) equipped with a He-Ne laser beam at 658 nm having a scattering angle of 90° at different temperatures. Each DLS measurement in the examples was repeated 5 times and an average value was obtained from the five measurements.
  • DLS dynamic light scattering
  • the particle size of poly (TEGST-VBA) NNH-DOX measured by DLS is shown in Fig. 15. As seen in Fig. 15, the average particle size of the polymer is about 574.1 + 3.6 nm with a polydispersity of 0.225.
  • the relative intensity (or Rel . Int.) is 89.94, the cumulative intensity (or Cum. Int.) is 34.16 and the diameter (or diam. ) is 232.54 nm.
  • Magnetite nanoparticles were synthesized by thermal decomposition of iron oleate complex in this example.
  • Example 4 The polymers obtained from Example 4 were used in the co-delivery of cancer drug doxorubicin (DOX) via the reaction of carboxylic acid groups with magnetite (Fe 3 0 4 ) nanocubes. Reaction of Fe 3 0 4 nanocubes with Polymers B, C and D was achieved via a three-step dialysis procedure.
  • DOX cancer drug doxorubicin
  • polymer B 45 mg was dissolved in 15 mL of toluene by heating to 80°C, followed by the addition of 300 ⁇ of Fe30 4 nanocubes dispersed in 20 mg/mL of toluene.
  • the solution was added to a dialysis tubing from Spectra Pro ® (Spectrum Laboratories, Inc., California, USA) with, a MWCO of 3500 Da, and dialyzed against toluene for 24 h.
  • the toluene was changed four times to allow for the exchange of polymer with the oleic acid on the surface of Fe 3 0 4 nanocubes.
  • tubing was dialyzed against ' DMSO for another 24 h.
  • DMSO was changed more than six times to remove toluene and the oleic acid residue completely .
  • TGA using PerkinElmer TGA 7 was performed by examining the solid samples obtained by freeze drying under air flow, with a ramp of 5°C/min between room temperature and 500°C.
  • the particle morphologies were determined using transmission electron microscopy (TEM) . Specifically, a drop of solution of nanoparticles was placed on a carbon- coated copper grid and air dried overnight. TEM studies were performed using ⁇ a FEI TecnaiTM G 2 F20 electron microscope at 200 kV (from FEI Company, Oregon, USA) .
  • TEM transmission electron microscopy
  • Such a core of MNs was not formed with polymer C as seen in Fig. 16(b), possibly due to the position of carboxylic acid groups on this polymer.
  • polymer D With polymer D, several MNs were found to aggregate to ' form one polymeric nanoparticle as seen in Fig . 16(c).
  • TGA thermal gravimetric analysis
  • Polymer B has a relatively narrower polydispersity of 0.12, as compared to polymer C having a polydispersity of 0.28 and polymer D having a polydispersity of 0.28.
  • the average particle sizes were 108 ⁇ 1 nm, 104 ⁇ 2 nm and 154 ⁇ 2 nm for B-MN, C- N and D-MN, respectively, at 20 °C.
  • the particle sizes of Polymers B, C and D are compared against B-MN, C-MN and D-MN and the graphs are shown in Figs. 18(a), (b) and (c) respectively.
  • the particle size of Polymer D decreased when loaded with MNs.
  • the MN-loaded polymeric nanoparticles have excellent stability from 20°C to 45°C.
  • the magnetite nanoparticles in B-MN were analyzed by XRD and shown in Fig. 19(a) . As seen in Fig. 19(a), the crystalline structure of the Ns (top curve) did not change after loading into Polymer B (bottom curve) .
  • HepG2 cells were used in this example and were maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 2 mM of L- glutamine, 100 U/mL of penicillin and 100 g/mL of streptomycin at 37 °C under an atmosphere with 5% C0 2 using a 75-mL plastic flask.
  • DMEM Dulbecco's modified Eagle's medium
  • FBS fetal bovine serum
  • penicillin 100 U/mL
  • streptomycin 100 g/mL of streptomycin
  • Two 5-cm Petri dish were seeded with 50,000 HepG2 cells in 2 ml/dish of DMEM for 24 h. 2 ml of B-MN solution was then added to each dish. One dish was placed above a magnet, and the other dish was not placed above any magnet. The two dishes were both kept in the incubator for 15 min and then their culture media were removed.
  • MN-P TEGSt-co-VBA
  • MN-P TEGSt-co-VBA
  • TEGSt-co-VBA TEGSt-co-VBA
  • Fig. 20 MN-P (TEGSt-co-VBA) -DOX had a lower toxicity intensity as compared to MN-P (TEGSt-co-VBA) carrying no doxorubicin. Accordingly, it can be concluded that Polymer B with conjugation of doxorubicin effectively targeted and reduced tumour growth, thereby leading to lower toxicity.
  • Balb/C mice of from about 20-30 g were purchased from Singapore Animal Center and used for the in vivo study.
  • 4T1 cells were maintained in Roswell Park Memorial Institute (RPMI) 1640 medium supplemented with 10% FBS, 2 mM of L-glutamine, 100 unit/mL of penicillin and 100 ⁇ g mL of streptomycin at 37 °C under an atmosphere with 5% CO 2 .
  • the 4T1 cells were subcultured as above.
  • mice To harvest 4T1 cells for subcutaneous seeding in mice, the cells were rinsed with PBS and detached by trypsin. Thereafter, the medium containing the cells was neutralized by RMPI 1640 medium with 10% FBS and centrifuged at 1000 rpm for 5 min. The cells were then washed with PBS twice to remove the FBS completely. They were dispersed evenly in free RMPI 1640 medium without FBS and injected subcutaneously near the belly- of the mice.
  • the samples were rinsed with deionized water, covered with ' Jung tissue freezing medium and dissected into slices of 10—12 ⁇ thickness using Leica CM3050S cryostat (L ' eica Microsystems GmbH, Germany) . Two sequential intersectional slices of the samples were sent for fluorescence imaging and Prussian blue iron staining for the distributions of doxorubicin- and MNs, respectively.
  • doxorubicin imaging one slice of sample was hydrated in deionized water and then dehydrated quickly with alcohol and xylene before mounting onto glass slides for fluorescence imaging with green light excitation.
  • the other slice of sample was stained with Sigma- Aldrich Accustain iron staining kit (HT20) according to the vendor's protocols. Briefly, the sample was hydrated in deionized water, placed in the working iron staining solution for 10 min and rinsed with deionized water. It was then stained in the working pararosaniline solution for 3-5 min and rinsed with deionized water again. The sample was next dehydrated rapidly with alcohol and xylene and mounted for microscopy imaging.
  • Sigma- Aldrich Accustain iron staining kit HT20
  • the disclosed core-shell nanoparticle avails its internal core space to the containment of compounds such as the drug and magnetic nanoparticles via chemical binding.
  • the drug and magnetic nanoparticles within this core structure may be further protected by an outer shell structure such that leakages of the core contents cargo due to breakages may be substantially minimized.
  • the availability of cleavable bonds between the core contents and the polymeric shell may facilitate the release of the core contents (for instance, therapeutic drugs) at a locality of a disease site .
  • the core-shell nanoparticle may be advantageous over the indiscriminate targeting of cells (such as in dendrimer-based carriers) by making available the option of magnetically-guiding the carrier to the site targeted for drug-release possible.
  • the magnetic nanoparticle encapsulated in the core may be non-toxic, biocompatible iron-oxide nanoparticles, which would eventually break down to form blood hemoglobin.
  • the core-shell nanoparticle may display strong passive and/or active targeting of tumors and a coordinated bio- distribution of its released cargo- compounds.
  • the core- shell nanoparticle may allow for real-time monitoring of the drug distribution at the target tissue. Hence, ⁇ the effect of therapeutics may be monitored as the disease progresses.
  • the core-shell nanoparticle may be used in medicine.
  • the core-shell nanoparticle may provide a synergistic approach to controlled drug therapy, when combined with a suitable technique (e.g. magnetic resonance imaging) in guiding and tracking the contained magnetic nanoparticles.
  • a suitable technique e.g. magnetic resonance imaging
  • drug therapy can be in the form of administered chemotherapeutics for use in the treatment of cancer.
  • the core-shell nanoparticle will also be applicable in hyperthermia techniques of treating cancer. In such a method, hysteretic heating of magnetic nanoparticles with alternating magnetic frequencies can be used to treat cancer with little damage to normal tissues as it avoids the marrow suppression that results from many drugs or high levels of radiation.

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  • Biotechnology (AREA)
  • General Engineering & Computer Science (AREA)
  • Medical Informatics (AREA)
  • General Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Immunology (AREA)
  • Radiology & Medical Imaging (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Medicines Containing Antibodies Or Antigens For Use As Internal Diagnostic Agents (AREA)

Abstract

L'invention concerne une nanoparticule à cœur-écorce conçue pour la distribution de médicaments qui comprend une écorce polymère encapsulant un cœur comprenant un médicament et un agent d'imagerie.
PCT/SG2012/000210 2011-06-09 2012-06-11 Nanoparticule à cœur-écorce WO2012169973A1 (fr)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3169336A4 (fr) * 2014-07-17 2018-04-04 Ohio State Innovation Foundation Compositions pour le ciblage de macrophages et autres cellules à expression élevée de cd206 et méthodes de traitement et de diagnostic
US10806803B2 (en) 2014-07-17 2020-10-20 Ohio State Innovation Foundation Compositions for targeting macrophages and other CD206 high expressing cells and methods of treating and diagnosis
US12006339B2 (en) 2022-05-20 2024-06-11 Navidea Biopharmaceuticals, Inc. CD206 targeted drug delivery vehicles carrying novel bisphosphonate drug payloads via a degradable linker
US12005122B2 (en) 2016-10-07 2024-06-11 Navidea Biopharmaceuticals, Inc. Compounds and methods for diagnosis and treatment of viral infections

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1973832A (zh) * 2006-10-24 2007-06-06 中山大学 具有ct示踪效应的可生物降解纳米药物胶囊及其制备方法
EP2210616A1 (fr) * 2009-01-21 2010-07-28 Centre National de la Recherche Scientifique Nanoparticules furtives polyvalentes pour une utilisation biomédicale
WO2010104865A2 (fr) * 2009-03-09 2010-09-16 The Regents Of The University Of California Nanocapsules à protéine unique utilisées pour l'administration de protéines avec effet durable
WO2011001351A1 (fr) * 2009-07-01 2011-01-06 Koninklijke Philips Electronics N. V. Véhicules réactifs à des stimuli pour délivrance de médicaments guidée par mpi

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1973832A (zh) * 2006-10-24 2007-06-06 中山大学 具有ct示踪效应的可生物降解纳米药物胶囊及其制备方法
EP2210616A1 (fr) * 2009-01-21 2010-07-28 Centre National de la Recherche Scientifique Nanoparticules furtives polyvalentes pour une utilisation biomédicale
WO2010104865A2 (fr) * 2009-03-09 2010-09-16 The Regents Of The University Of California Nanocapsules à protéine unique utilisées pour l'administration de protéines avec effet durable
WO2011001351A1 (fr) * 2009-07-01 2011-01-06 Koninklijke Philips Electronics N. V. Véhicules réactifs à des stimuli pour délivrance de médicaments guidée par mpi

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
BLANCO, E ET AL.: "Mini Review: Multifunctional Micellar Nanomedicine for Cancer Therapy", EXPERIMENTAL BIOLOGY AND MEDICINE, vol. 234, 2009, pages 123 - 131 *
DATABASE WPI Derwent World Patents Index; AN 2007-847873 *
WANG, H. ET AL.: "Folate-targeting magnetic core-shell nanocarriers for selective drug release and imaging", INTERNATIONAL JOURNAL OF PHARMACEUTICS, vol. 430, 2012, pages 342 - 349 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3169336A4 (fr) * 2014-07-17 2018-04-04 Ohio State Innovation Foundation Compositions pour le ciblage de macrophages et autres cellules à expression élevée de cd206 et méthodes de traitement et de diagnostic
US10806803B2 (en) 2014-07-17 2020-10-20 Ohio State Innovation Foundation Compositions for targeting macrophages and other CD206 high expressing cells and methods of treating and diagnosis
US12005122B2 (en) 2016-10-07 2024-06-11 Navidea Biopharmaceuticals, Inc. Compounds and methods for diagnosis and treatment of viral infections
US12006339B2 (en) 2022-05-20 2024-06-11 Navidea Biopharmaceuticals, Inc. CD206 targeted drug delivery vehicles carrying novel bisphosphonate drug payloads via a degradable linker

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