DE10050870A1 - Biocompatible composite material for medical applications - Google Patents

Abstract

The invention relates to a protein-free, biocompatible and resorbable micro-composite material, its production and various uses in medicine. DOLLAR A The material or biomaterial consists of a matrix of poly-beta-hydroxyalkanoates, into which water-swellable microparticles, composed of natural polyelectrolytic biopolymers and / or polyelectrolyte components of polysaccharide origin, together with very easily water-soluble, pore-forming particles and together with them Polymer crystallization promoting nanoparticles are embedded. The pore-forming particles consist of the same substances that are used in the culture medium of cell cultivation. The biomaterial can preferably be used as a flat structure, but also as a compact biomaterial. As a flat structure, it has application-specific shaped micro and macro pores and / or slits. DOLLAR A The biomaterial is intended, for example, to cover large wound surfaces, to cultivate adhesive human and animal cells, to seal implantable vascular prostheses, as a barrier for separating organs, to prevent adhesions and as a transplant material.

Description

The micro-composite materials according to the invention consist of biological materials or of natural origin and can be used for very different medical applications gene can be used. So wounds can be covered with the composite material, to protect them from negative environmental influences and to heal through creation to promote a favorable physiological environment. It has long been known that a moist environment and a certain oxygen supply will heal the wound accelerated. The fabrics according to the invention are available in one embodiment The cover is particularly suitable for large wounds. Other uses are the separation of organs by fabrics, e.g. B. after abdominal surgery or at heart to prevent adhesions. Also for the sealing of textiles Vascular prostheses, for which autologous blood is often still used, can the composite material according to the invention can be used.

In addition, it can serve as a carrier material for animal and human cells, which are grown on or in the pores of the material and subsequently with it in organs or on the wound surfaces. For example, ephitel cells, Endothelial cells, Langerhans islet cells, liver cells, skin cells, divisionally active Hair root cells or keratinocytes are grown on or in the material. A preferred area of application is the difficult to heal chronic wounds and the extensive burns. By applying the invention, the tissue regeneration and ingrowth of implants in humans and animals improved. Tissue vascularization is stimulated. The composite material is absorbed without residue in the course of the healing process.

Animal and vegetable products are considered as biocompatible resorbable materials or biocompatible synthetic or semi-synthetic polymers are widely used. It gives a relatively large number of property rights.

A number of implant materials and wound coverings are based on polymers, Homopolymers and copolymers of resorbable polyglycolide / polylactide (US 3636956, US 3463658, US 3982543, RU 2125859).

Polyalkanoate esters like the poly-β-hydroxybutyrate are in the form of cast films as well used in the form of compact implant material. US 5641505 makes porous flexible membranes or tubes with wall thicknesses of approximately 10 µm to 1 mm and pores size between 0.1 and 30 µm from polyhydroxybutyrate, from a copolymer of poly β-hydroxybutyrate and poly-β-hydroxyvalerianate or combination of poly-β- Hydroxybutyrate with copolymers between the two polymers under protection. The Material is bioresorbable and contains pores with a pore diameter through which Water and salts are exchanged but cells cannot pass through. You will for proposed healing of soft tissue.

To make a stable from the physiologically advantageous water-soluble hyaluronic acid Material to be obtained are hyaluronic acid esters or chemically cross-linked Hyalu ronic acid or self-crosslinked hyaluronic acid (US 5,874,417, WO 9,707,833, EP 0.850.074, AU 6.930.096, WO 9.808.876, EP 0.922.060, US 5.939.323, US 4.957.744, IL 84.032, INI 170.801) proposed for medical and cosmetic applications.

Hyaluronic acid esters, e.g. B. with the brand name HYAFF (Fidia, Italy), is for Wound care (hyalgin, laserskin) offered. The films made from HYAFF are mechanically stable and can be provided with arrays of pores, the herge with laser be put. The pores are said to allow oxygen entry and drainage of wound fluid effect: Above all, however, they have the function that the skin cells pass through them len to the wound surface. WO 9.707.833, EP 0.850.074, AU 6.930.096, WO 9.808.876 and EP 0.922.060 use membranes made of hyaluronic acid esters or cross-linked  Hyaluronic acid derivatives to prevent postoperative adhesions.

The swellability and the hydrophilicity of the polyhydroxyalkanoate esters as well as the Hyalu ronic acid esters as the main criterion of biocompatibility are due to the hydro phobic character of these semi-synthetic materials is relatively low. Your use as a carrier material for animal and human cell cultures is in need of improvement.

There are various methods to increase the hydrophilicity in synthetic and semisynthetic polymers proposed.

US 5,849,368 describes a process to make non-polar or slightly polar, hydrophobic Plastic or rubber surfaces using plasma and subsequent To make coating with hydrophilic materials hydrophilic. The coatings from Medical products or implants with hyaluronic acid are described in WO 9.624.392 cited. A wound covering made of a hydrophobic porous membrane, which was coated hydrophilic with a nonionic surface-active substance, protects EP 0.470.007.

US 5,916,585 is concerned with hydrophobic biodegradable polymer material on the Surface a hydrophilic polymer was immobilized or chemically cross-linked.

To change the material properties, polymeric composite materials, consisting of microspheres embedded in a matrix, proposed Man expects the properties of the starting materials to be reflected in the material leave that. US 5,977,428, WO 9,828,013 expose hydrolytically labile microspheres cross-linked polysaccharides with diameters between 1-100 µm in a hydropho ben adhesive matrix material.

WO 0.037.124 and US 5,644,049 use a biodegradative network from Hyalu ronic acid esters in the form of a film, a membrane, a sponge, a hydrogel, a guide channel, thread, sponge, gauze or not woven, cross-linked hyaluronic acid as a carrier of mammalian cells, being as biological active component microspheres, sponge fragments, fibers and granules from Hyalu ronic acid derivatives are included. The material can be used in biomedical and sanitary Applications including dermatology, urology, orthopedics, otology microsurgery, plastic surgery and in the cardiovascular system.

U.S. 5,766,631 describes implant materials that contain bioabsorbable microspheres a diameter between 10 µ and 1,500 µ in a freeze-dried, very hydro contain phile and biocompatible collagen matrix and the poly lactide / polyglycolic acid copolymers, collagen, cross-linked collagen, hyaluronic acid and cross-linked hyaluronic acid, alginate and cellulose derivatives, collagen, polystyrene, dextran, Polyacrylamide, cellulose, calcium alginate, latex, polysulfone or glass can exist. A material made of polytetrafluoroethylene for vascular prostheses contains microspheres a biodegradable material (US 5,716,660).

WO 9.961.080 and AU 4.368.099 describe materials containing hyaluronic acid derivatives three-dimensional structures, including cavities, communicating pores or Na deln, contain fibers of the same material and for temporary tissue replacement serve.

Polymer microspheres with a diameter between 10 nm to 2 mm, consisting of a water-insoluble polylactide or from polyhydroxybutyrate and their preparation US 5,922,357 describes biomedical applications. The microspheres are with a water-soluble polymer such as dextran, chitosan, pectin, hyaluronic acid cellulose, Coat starch, pullulan, inulin, heparin and heparin-like synthetic polymers tet.

Hyaluronic acid in native form is a frequently used component of materials A formulation in the form of liquid, cream, gel gel, hydrogel, hydrocolloid or cover for the treatment of wounds contains hyaluronic acid and plasma fibronectin  as components of the amniotic fluid (US 5,604,200) which is a moist Environment as they exist in a fetus in the uterus, evokes and with the scald open wounds. Hyaluronic acid is because of its humani dental composition (WO 0.016.818 and US 4,813,942) of particular Significance for wound coverings.

A framework material derivatized with hyaluronic acid for various medical purposes Purposes such as tissue regeneration, tissue reconstruction and wound healing and one US 5,955,578 describes the method of production. The materials can be organic contain active molecules like BMP.

In addition to the human identity of hyaluronic acid and the associated high bio Compatibility is particularly the angiogenic effect, promoting wound healing as well generally of importance to the growth promotion of various cells. According to US 5,925,626 stimulate hyaluronic acid fractions with molecular weights from 50,000 D to 100,000 D wound healing is particularly good. US 5,644,049 describes materials made from an interpenetrating polymeric network, one component being a acidic polysaccharide such as hyaluronic acid or a derivative thereof, and which second component is a synthetic polymer.

In addition to the above Hydrophobic and hydrophilic materials become sulfated glycosa minglycane proposed as ingredients of wound coverings and implants. Other property rights use poorly soluble polyelectrolytes. According to US 5,902,798 the Accelerate wound healing with heparin or heparin sulfate in the presence of chitosan nigt. The use of carboxymethylchitosan for wound healing is described in US 5,679,658 proposed. US 5,929,050 describes compositions containing chondroitin sulfate and Contain glycosaminoglycans. US 4,570,629 provides hydrophilic bipolymeric copolyellek trolytic material from linear water-soluble anions such as keratin and an in Water soluble linear cationic biopolymer based on collagen and Glucosaminoglycan under protection. WO 0.016.817 describes a dermal scaffold Chitosan / collagen for wound healing, EP 0.477.979 mentions chitin / chitosan as wound healing the filling material of wounds.

WO 9.822.114 sets to accelerate tissue repair z. B. chitosan, chitin and Glucosamine, hyaluronic acid and sucrose octasulfate.

US 5,520,916 and US 5,824,335 use threads embedded in a matrix. The threads can be made of esters of hyaluronic acid or a combination of esters of Alginic acid exist.

The materials are used according to the state of the art depending on the application Pore.

So that the wound exudate can run off and air can get to the wound, pores become different sizes introduced into the material. A certain pore size should do that Allow cells to grow through to the base of the wound, on the other hand Materials that are supposed to prevent tissue growth by correspondingly small Pores are blocked from cell access. A mesh made of polyester (US 5,972,332) is used to transfer keratinocyte cell turf directly to the wound surface. Smaller pores are said to prevent microorganisms from growing through.

The disadvantage is that the physiologically very advantageous hyaluronic acid and its salts in Water are soluble and therefore not a mechanically stable material under moist conditions form. With the absorption of body fluids or wound exudate, one also forms increasing dilution less viscous liquid. To overcome this disadvantage to deal with it, the hyaluronic acid was crosslinked or derivatives such as the hyaluron acid ester used. The derivatives are sparingly or not soluble in water; your functional groups that produce beneficial physiological properties,  are blocked, however.

It is particularly disadvantageous that the semi-synthetic hyaluronic acid ester under physiological conditions not only in the physiologically very favorable hyaluronic acid but also breaks down into cell-toxic alcohols such as butanol. The latter leads to rapid absorption to local inflammatory reactions.

A disadvantage with the chemically cross-linked hyaluronic acids as well as with all others crosslinked materials is also used for crosslinking toxic crosslinking agents be set.

Polylactide films are also used for wound care and for closing Organ or tissue defects suggested. Polylactide is a mechanically stable, synthetically produced polymer that breaks down into lactic acid in the organism. they are somewhat less hydrophobic than the hyaluronic acid esters. The lactic acid leads to the Absorption in the body to local accumulations of lactic acid, which leads to tissue irritation lead.

Also the flexibility and softness of the films or Membra made from polylactate is often not sufficient.

Materials of animal origin such as collagen are no longer recommended, because they can transmit infectious material and are allergenic due to their protein structure can work.

In addition to the flexibility and softness of the fabrics, important properties are Adhesiveness and swellability of the surface. The surface is in direct contact with the cells or with the tissue and determines their physiological properties. On another key consideration in the development of new biomaterials is that the production should be done in a simple way or that the possibility of practi and commercial use. This is ge in many of the patent literature mentioned materials not the case.

The invention is based on the object of producing a new biodegradable material len, which can be used for a variety of medical applications. The Material is said to be of biological origin, but not from mammals and none Contain protein.

The desired material should be used in a variety of ways, e.g. B. in the cover or Sealing or sealing of organ and tissue defects, as a carrier in cell cultivation, for covering large wound surfaces, for sealing vessel walls and of implants and as a resorbable implant for separating organs. It is said to have a beneficial effect on the healing of organ and tissue defects and do not have the disadvantages of previous materials. In particular, they should combine good flexibility with high hydrophilicity and swellability of the surface.

In one version, the cultivar should be on the material or in the pores as a carrier Adhesive human or animal cells take place and the overgrown carrier for Tissue defects, especially chronic, difficult to treat desires the or from burns are used.

The cultivation of animal cells z. B. of keratinocytes on the support material preferably on flat surfaces. The carrier materials should be so flexible that they nestle against the irregular surfaces of the wound surface. The cells located on the carrier material are said to be larger through macropores, openings can grow through to the wound surface through 10 µm. The wound coverings or carrier materials should be degraded after a time and new tissue attached to it Place.

It must therefore be found a material that is completely biocompatible, in the  Body can remain without irritation and which within a certain Period without harmful side effects or occurrence of toxic products is broken down or absorbed. The surface should have swellable properties and the inside is said to be connected to the outside by pores. The mate rial should be easy to manufacture and commercially usable without much effort his.

The invention thus intends to overcome the disadvantages of the previously known resor avoidable biomaterials and plastics for implants. You should be at for example, the disadvantages of other biodegradable materials, especially theirs high hydrophobicity, their very low swellability and adherence and insufficient Do not have biocompatibility. The mechanical properties are said to be light Manageability for the attending physician. In addition, the areas should structures in a planar form but also in a form adapted to the organs or implants Shape can be produced in a simple way.

The scientifically technical object of the invention is one for diverse Applications in medicine suitable biocompatible and absorbable material to propose which also meets commercial requirements.

The object on which the invention is based is achieved in that the two per se known biocompatible, very different in their properties and not alone Types of biopolymers suitable for the intended applications polymeric micro-composite material are joined together.

According to the invention, the new composite material consists of hydrophobic polyalkanoate esters as a matrix, which microparticles consisting of one or more polysaccharide polyelectrolytes and / or their salts and / or their derivatives with spherical, fibrous or irregular shape with a diameter between 0.1 µm to 500 µm and / or easily water-soluble pore-forming particles and / or the polymer crystals Nanoparticles promoting stallite formation and, if necessary, auxiliary substances, active substances or medic contains chemicals and is provided with macropores or slit-shaped openings. The new material is a micro-composite material consisting of a hydrophobic matrix with hydrophilic fillers.

Poly-β-hydroxybutyrate is preferably more biological as the matrix-forming polyalkanoate ester Origin chosen.

The strength of the matrix-forming material is according to the invention by attached Affects nanoparticles that improve polymer crystallite formation.

Auxiliaries, active substances or medicaments present in the material according to the invention additionally influence the physiological properties of the material.

The polyelectrolytic microparticles according to the invention in the matrix should be as possible be small. A diameter smaller than 10 µm is preferred. The particles create one swellable, soft and biocompatible surface of the material. It is advantageous that the Material composites according to the invention have sufficient strength with a high biocompa exhibit flexibility. The surface and the interior of the material are hydrophilic Properties and a certain swellability by the inventive Microparticle is caused. It can be assumed that the polyelectrolytic Properties of the microparticles according to the invention in particular when water is ingress High osmotic swelling pressure arises in the area of the microparticles, which is important for the tissue similar mechanical properties of the surfaces of the composite material and the fabric made from it is responsible. Especially the polyanioni The biopolymers that make up the microparticles or those made of polyelectro lyt complexes released under physiological conditions have a great effect probably the swelling pressure via the repulsion of the chains of the same ionic charge.  

This also occurs with strong dilution with water. The fluid access in that Interior of the materials is due to macropores as well as the content of washable ren, or pore-forming particles guaranteed.

The mass ratio between polyalkanoate ester (PAE) and the polysaccharidic Polyelectrolytes, their salts or derivatives (PE) are according to the invention between PAE: PE = 0.3 to PAE: PE = 100.

In a preferred embodiment of the invention, the microparticles consist of the very easily and completely water-soluble polyanionic hyaluronic acid or in a another version made of pectic acid, xanthan and or their salts and / or their derivatives. Derivatives are the uronides of hyaluronic acid or pectic acid or the sulfated polysaccharides.

The uronides are broken down by the partial breakdown of hyaluronic acid with the enzyme Hyaluronate lyase or pectic acid obtained with the enzyme pectate lyase. Advantageous them is that because of the double bonds they are very intense radical trapping and possess angiogenic properties with limited swellability, properties that transfer them to the material. They promote cell growth and the healing process similar to natural hyaluronic acid. They become lighter than the high molecular ones Hyaluronic acid from the matrix surface by using water to form pores Pore sizes from 0.1 µm to 1 mm washed out.

Sulphated polyelectrolytic polymers, preferably sulphated hyaluronic acid with sulphation Degrees between 0.1 and 3.9, preferably 1 to 3, decrease due to their presence the adhesive behavior of blood and animal cells on the surface of the material. By their presence as a minor component can thus regulate the adhesion of the cells become. Their presence according to the invention in films which are used for Separation of organs after operations with the aim of avoiding guarding solutions or to seal textile vascular implants.

In another embodiment, the microparticles become heavier in water soluble, but water-swellable alkaline earth metal salts of alginic acid, which is only under slightly acidic pH conditions soluble polycationic chitosan or the poorly soluble Chen polyelectrolyte complexes of chitosan with the polyanioni according to the invention rule biopolymers, preferably with hyaluronic acid.

The material composed according to the invention is specific to the application Presence of other constituents or through special designs of the manufacturer development process varies.

The pore-forming, water-soluble particles are removed from the matrix when liquid enters detached and leave pores up to a size of 1 mm. The particles exist According to the invention preferably from crystals or aggregates of substances contained in the Culture media from cell culture are present such as glucose, sucrose, L-amino acids, Sodium bicarbonate, sodium or potassium phosphates, magnesium sulfate, potassium chloride or table salt. The diameter of the pore-forming particles determines the pores knife. Pores can appear in the material as open, closed or continuous cavities me be present.

It was known that pores were formed by leaching salt crystals Can produce water in cast films. What is new is an embodiment of the invention that leaching only during application of the cast films in an aqueous environment exercise as it exists in the human body or in a cell culture. So that will avoided the problem that an independent leaching step to unwanted Loss of polyelectrolytic polymers would result. The composition of the In its composition, the culture medium must also be leached taken into account constituents supplied. The pore-forming particles exist  according to the invention preferably from glucose, sucrose, L-amino acids, sodium bicarbo nate, sodium or potassium phosphates, magnesium sulfate, potassium chloride or table salt.

Furthermore, an embodiment of the invention is very effective for improving the porosity the materials that use an enzymatic leaching process.

According to the invention, materials containing hyaluronic acid or hyaluronic acid are used a leaching step with an aqueous solution which is between 1,000 and Contains 100,000 IU of the enzyme hyaluronate lyase. The surface near polymer particles and voids remain. In parallel also the pore-forming particles dissolved to form further cavities. Through this Embodiment of the invention is a strong porosity of the near-surface layer reached the material. In analogy, pectic acid and pectic acid are containing Treated materials.

Macro pores have sizes between 10 µm to 1 mm, micro pores are smaller than 10 µm.

According to the invention, in one embodiment, nanoparticles made of different Material, e.g. B. from titanium dioxide with particle sizes between 10 nm to 1 micron the Suspen sions added. It was found that the polymer crystallite formation of the Polyester matrix can be reinforced. It is advantageous for certain designs if the physika through increased polymer crystallite formation of the polyalkanoate matrix misch / mechanical properties of the matrix, such as tensile strength and Tear resistance can be improved.

According to the invention, a water-soluble plasticizer, preferably a Esters of citric acid are added in the manufacture of the material. The soft machiner prevents embrittlement of the material and increases flexibility. It is advantageous that water soluble plasticizers of the citric acid ester type by washing out can be easily removed and then unhindered cell growth takes place det.

Drugs or active ingredients can be present in the material according to the invention. For example, antiobiotics or anti-inflammatory or blood clotting inhibiting agents are used. The hyaluronic acid uronides and the sulfated polysaccharides, for example of the sulfated hyaluronic acid type have in addition to their structuring properties as material components Drug properties.

It was not to be expected that the composite material according to the invention would be surprisingly good would have physiological properties and such a pronounced biocompatibility. It turned out to be very advantageous that the microdisperse polyelectrolytic particles create a biocompatible hydrophilic outer and inner surface in the materials, which has mechanical properties similar to those of natural tissue. The use of hyaluronic acid, its salts and their is particularly advantageous Uronides as polyelectrolytic particles according to the invention. Have these connections outstanding wound healing, angiogenic and radical trapping properties in native form companies. These properties remain in the composite material according to the invention Contrary to the chemically cross-linked hyaluronic acids or the hyaluronic acid esters receive. It is advantageous that the composite material activates the macrophages, which the Release growth factors that promote cell growth.

The preferably used hyaluronic acid enclosed as microdisperse particles remains, although water soluble, essentially in the matrix of Material. It swells and regulates further water access. By swelling the cast films become very flexible. Due to the adherent surface are also flawed gel-shaped wound surfaces largely covered. For the same reason  the adherence of adherent cells is promoted.

The area around the macropores and the inner walls of the macropores proved to be as particularly suitable for cell cultivation. For example, keratinocytes colonize before moves this area. From here, they quickly grow on the wound surfaces Without restricting the invention, the invention is intended to be by some parameters and fro position variants are explained.

The suspension contains dissolved polyalkanoate esters, microparticles, pore-forming Particles and other constituents are suspended in an organic solvent. The Suspension is applied to a mold and by evaporating the organic Solvent or by precipitation with a suitable other solvent such as ethanol or solidified water on a mold in a manner known per se. Solvent for the Polyesters are, for example, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, Tetrahydrofuran, chloroform, methylene chloride, lactic acid ester or morpholine. Light volatile. Solvents such as chloroform are removed by evaporation. Involatile Solvents such as the lactic acid esters or morpholine can by water or by Water / ethanol are removed. The latter precipitation method leads to very porous ones Material.

In one version, the form consists of a flat surface, in another a textile knitted fabric, for example a vascular implant or has an irregularity moderately shaped surface. Flat structures or membranes according to the invention have a thickness of 1 µm to 500 µm, preferably 10 µm, depending on the application up to 20 µm.

Experience has shown that when flat fabrics or cast films or membranes are produced, the realizable area sizes are between the cm ² and m ² ranges. They can have continuous macropores, the opening width of which is approximately between 10 µm and 1.0 mm, or arrangements of slots with lengths between 1 and 10 mm. The latter are produced according to the invention by cutting with a cutting tool. Other macropores can be produced in a known manner by piercing with piercing tools or using laser beams. The macropore makes the material permeable to the cells cultivated on the film surface. The growth of the wound surface through divisible skin cells is made possible. In addition, the wound exudate can flow off when the cast films are used as a wound covering.

According to the invention, a micro- to macroporous structure is also produced by the a highly viscous suspension according to the invention with a content of at least 40 g / l, Polyhydroxyalkanoate is produced and in this solution an aqueous solution of Is suspended polyelectrolyte, which may have been mixed with an amount of ethanol, where the polyelectrolyte just doesn't fail yet. After evaporation, for example the Chloroforms form in the cast films depending on the size of the suspended particles Micro and macro pores.

The syrup-like, highly viscous state of the suspension prevents demineralization the organic and the suspended aqueous phase during the casting pro zesses.

According to the invention, a micro- to macroporous structure is also formed by the pore formation particles preformed and after washing them out with water or during the Cultivation with cells or formed after implantation. You are in the material as out washable, physiologically compatible, easily water-soluble particles contained in the matrix are suspended. The particles dissolve in the tissue fluid or after implantation during cell cultivation in the medium of cell cultivation with the formation of cavities. The According to the invention, material can also be used with hyaluronate lyase or pectin lyase solutions  be treated.

Other fabrics according to the invention are created by dipping shapes into the Suspension of the polyelectrolytic microparticle and the polyalkanoate ester in one organic solvent and subsequent evaporation of the solvent and given if repetition of the procedure. The fabric can then be of the shape removed or it can remain on the mold. Especially in the case of an Abdich That remains of natural tissues or porous, textile vascular implants Material as a thin film on the surface or between the meshes of the implant.

The culture of cells on and inside the material according to the invention takes place with Cells of different origins such as epithelial cells, endothelial cells, and Langer Hans' islet cells, liver cells, skin cells, dividing cells of the hair root and Keratinocytes. In order to colonize cells, the material becomes known with one cell culture medium overlaid and, if necessary, moved slowly. After about The pore-forming particles are washed out for 6 hours and the culture is carried over inoculates adherent cells. After overgrowth, the materials are removed and implanted under aseptic conditions or placed on wound surfaces.  

example 1 Fine cleaning of the 3-PHB

100 g of 3-polyhydroxybutyrate (3-PHB) with a molecular weight of 1,200 kD are combined with 50 g of silica gel 1020 P (chemical plant Bad Köstritz) mixed with 5 l of freshly distilled chloroform and 1 hour with heating to temperatures in the range of 62 ° C using a Reflux condenser stirred. The silica gel was previously at a temperature of 10 hours 180 ° C, heated in a drying oven to remove pyrogens. The suspension will by filtration at temperatures of about 50 ° C-60 ° C through a filter with a pore size filtered from 10 µm-25 µm (Seitz T 1500). The filtrate is mixed with 100 ml of chloroform and again mixed with 10 g of silica gel 1020 P (chemical plant Bad Köstritz) and with heating stirred at temperatures of about 60 ° C for 1 hour. Then the suspension is through a filter with a pore size of 3 µm-8 µm (Seitz T 500) at temperatures of 50 ° C Filtered 60 ° C. Then the 3-PHB is poured into 80% aqueous methanol precipitated. The 3-PHB is washed with ethanol and then at 40 ° C in a vacuum oven Dried cupboard. A purified 3-PHB is obtained which is used to prepare the Ver bundle materials are used according to the following examples.

Example 2 Casting a small-pore film (pore size 20 µm to 100 µm)

60 g of 3-PHB produced according to example 1 is fresh in one liter distilled chloroform dissolved. 4 g of an aqueous solution containing 20 g / l, Sodium salt of hyaluronic acid with a molecular weight in the range from 1,300 to 1,700 kD contains, as well as 3.2 ml of absolute ethanol and the solution stirred vigorously until the droplets Chen the aqueous phase are homogeneously suspended.

The suspension is spread with a squeegee on a glass plate. The distance of the Squeegee edge to the glass surface (gap width) is 500 µm. After drying the coating Glass plates under a fume hood to remove the chloroform and stand in the air under clean room conditions, the film is swollen with a little injection water and then lifted from their base. After drying the film in air at 56 ° C and Removing the water creates foils that are about 20 µm thick and have pores in the size range range from 10 µm to 100 µm.

Example 3 Pour a large pore film

A film is produced as in Example 2, but the addition of ethanol is omitted. It is formed Pores with pore sizes between 20 µm to 500 µm.

Example 4 Pour on a plastic band

The starting materials are prepared as in Example 2. The casting solution is on a tape-shaped film made of polyterephthalate and a width of 20 cm, which is with a Speed of 2 m / min moved uniformly under the stationary doctor blade, at a gap width of 300 microns applied. This is followed by drying under pure room conditions at 56 ° C to 58 ° C.  

Example 5 Pouring a non-porous film containing hydrocolloid particles

45 g / l 3-PHB in chloroform are mixed with 250 mg hyaluronic acid, which is a particle knife less than 5 microns, suspended with vigorous stirring. The resultant, equal moderately cloudy suspension is applied with a doctor blade spacing of 500 µm on glass plates painted. After drying in air at room temperature, foils with a Film thickness of 20 µm, which contains inclusions of the hyaluronic acid particles.

Example 6 Films with restricted pore size distribution

The procedure is as in Example 2. In addition to the 3-PHB / chloroform solution added sodium hyaluronate solution with 19 g / l, sodium hyaluronate with a molecular weight of 800-kD additionally phenylalanine added in a concentration of 1 g / l. After pouring and drying according to Example 2, a small-pore film is formed.

Example 7 Use of hyaluronic acid uronide in porous films

According to Example 3, the sodium salt is replaced by the sodium salt of hyaluronic acid of hyaluronic acid uronide with a molecular weight of 20 kD. After pouring and Drying according to example 2 produces a large-pore film.

In a parallel experiment, L-phenylalanine is added as described in Example 6. It many small pores form.

Example 8 Pour a very thin film

30 g / l, 3-PHB are poured as in Example 4 with a doctor blade spacing of 250 microns. The Film thickness of the films obtained after drying is 8 μm.

Example 9 Coating using a corona discharge

3-PHB film according to Example 4 is cast on a plastic tape made of polyterephthalate. The result is 3-PHB composite material films with a layer thickness of approximately 15 µm, which adheres to the plastic tape. After drying at 58 ° C, the film lying on the plastic tape is activated by passing the tape through a corona discharge. The film is then sprayed with an aqueous 1% sodium uronide solution. The amount applied is 1 ml to 3 ml per 100 cm ² . The molecular weight of the uronide is 15 kD.

Example 10 Foil containing plasticizers

A 45 g / l, 3-PHB containing chloroform solution and solid hyaluronic acid particles correspond According to Example 4, 100 μl of citric acid triethyl ester are added. With a squeegee spacing a film of 500 µm is cast according to Example 3. A stretchy one is created Foil with an average foil thickness of 12 µm.  

Example 11 Addition of glucose particles

In a film production according to Example 5, an additional 200 mg of glucose particles suspended in the solution with a particle diameter of about 30 microns. After manufacture of the films according to Example 5, films are formed which have no pores. After Einbrin The foils in a submerged cell culture medium are formed by dissolving out the glucose particles and the hyaluronate particle pores with a diameter of about 25 microns.

Example 12 Addition of saline particles

In a film production according to Example 5, an additional 200 mg of saline particles suspended with a particle diameter of about 30 microns. After making the slides according to Example 5, films are formed which have no pores. After the Foils in a submerged cell culture medium are formed by removing the saline particles and the hyaluronate particle has pores with a diameter of approximately 25 μm.

Example 13 Films containing hyaluronate and chitosan

0.01 g of chitosan are suspended in 10 ml of distilled water and stirred Add dropwise concentrated acetic acid until the chitosan has dissolved. In the Solution are given 5 ml of a solution containing 2 g / l sodium hyaluronate. The fancy lene gel-shaped polyelectrolyte complex consisting of chitosan and hyaluronic acid filtered off and washed with water. The gel is passed through a sieve with a pore size of 50 microns pressed and the resulting gel particles then in a 3 PHB / chloroform solution suspended. A film according to Example 4 is produced with the solution.

Example 14 Spray on acetic acid chitosan solution

A chitosan solution is sprayed onto a film strip produced in accordance with Example 4 in a second pass. To prepare the citosan solution, 0.05 g of chitosan is suspended in 1 l of distilled water and, while stirring, concentrated acetic acid is added dropwise until the chitosan has dissolved. The spray density is in the range of about 20 spray drops per mm ² with an average drop volume of 0.01 µl. The film is then dried at 58 ° C.

Example 15 Spraying hyaluronic acid solution on a chitosan-containing film

0.01 g of chitosan are suspended in 5 ml of distilled water and stirred Add dropwise concentrated acetic acid until the chitosan has dissolved. This Solution is suspended in 1 l of a 3-PHB / chloroform solution according to Example 2 and it foils are poured. After the films have dried, a solution of 0.05 g / l hyaluron acid sprayed as about 2 µm to 5 µm as a thin layer on the film. The sprayed foils are then dried at room temperature.

Claims (37)

1. Biocompatible, protein-free and resorbable micro-composite material for medical applications, characterized in that a matrix of polyalkanoate ester-embedded microparticles of one or more polysaccharidic polyelectrolytes and / or their salts and / or their derivatives with a diameter of 0.1 µm to 500 µm and / or easily water-soluble pore-forming particles and / or nanoparticles which promote polymer crystallite formation and optionally auxiliary substances, active substances or medicaments and that it is provided with pores or slit-shaped openings. 2. Micro-composite material according to claim 1, characterized in that the Matrix preferably consists of polyhydroxybutyrate (PHB). 3. Micro-composite material according to claims 1 and 2, characterized in that the mass ratio between polyalkanoate ester (PAE) and the polyelectro lytes, their salts or derivatives (PE) from PAE: PE = 0.3 to PAE: PE = 100 lies. 4. Micro-composite material according to claims 1 and 2, characterized in that the microparticles contain polycationic and / or polyanionic biopolymers. 5. Micro-composite material according to claims 1 and 2, characterized in that the microparticles are a polyelectrolyte complex consisting of a polyanionic and a polycationic biopolymer. 6. Micro-composite material according to claims 1 and 2, characterized in that the microparticles contain polyanionic, sulfate-containing biopolymers. 7. Micro-composite material according to claims 1 and 2, characterized in that the microparticles of sulfated hyaluronic acid with degrees of sulfation from 0.1 to 3.9, preferably from 1 to 3 included. 8. Micro-composite material according to claims 1 and 2, characterized in that the microparticles contain hyaluronic acid and / or its salts. 9. Micro-composite material according to claims 1 and 2, characterized in that the microparticles contain uronides of hyaluronic acid and / or their salt. 10. Micro-composite material according to claim 1, 2 and 9, characterized in that the hyaluronic acid-containing or hyaluronic acid-containing Materials with an aqueous solution containing the enzyme hyaluronate lyase, be treated. 11. Micro-composite material according to claim 1 and 2, characterized in that the Microparticles contain pectic acid and / or its salts. 12. Micro-composite material according to claims 1 and 2, characterized in that the microparticles contain uronides of pectic acid and / or their salts.   13. Micro-composite material according to claims 1, 2 and 12, characterized in that that the pectic acid-containing or pectic acid-containing materials with a aqueous solution containing the enzyme pectate lyase, are treated. 14. Micro-composite material according to claims 1 and 2, characterized in that the microparticles contain alginic acid and / or its salts. 15. Micro-composite material according to claims 1, 2 and 14, characterized in that that the microparticles contain calcium and / or magnesium salts of alginic acid th. 16. Micro-composite material according to claims 1 and 2, characterized in that the microparticles contain xanthan and / or its salts. 17. Micro-composite material according to claims 1 and 2, characterized in that which contain chitosan microparticles. 18. Micro-composite material according to claims 1 and 2, characterized in that the microparticles are a mixture of polycationic and polyanionic Contain polyelectrolytes. 19. Micro-composite material according to claims 1 and 2, characterized in that the microparticles are a polyelectrolyte complex consisting of chitosan and Contains hyaluronic acid and / or its uronides. 20. Micro-composite material according to claims 1 and 2, characterized in that the. Microparticle a polyelectrolyte complex consisting of chitosan and Xanthan. 21. Micro-composite material according to claims 1 and 2, characterized in that the matrix microparticle is a polyelectrolyte complex consisting of chitosan and Contains pectic acid and / or its uronides. 22. Micro-composite material according to claims 1 and 2, characterized in that the material as cast film in the form of a membrane with a thickness of 1 µm to 500 microns, preferably 10 microns to 20 microns is produced. 23. Micro-composite material according to claims 1, 2 and 22, characterized in that that the cast film contains water-soluble, biocompatible pore-forming particles. 24. Micro-composite material according to claims 1, 2 and 22, characterized in that that in a suspension according to the invention with a content greater than 40 g / l dissolved polyhydroxyalkanoate an aqueous or ethanol-containing aqueous solution one of the polyelectrolytes is suspended. 25. Micro-composite material according to claims 1, 2 and 23, characterized in that that the pore-forming particles preferably consist of glucose, sucrose, L-amino acids, sodium bicarbonate, sodium or potassium phosphates, Magnesium sulfate, potassium chloride and / or table salt exist.   26. Micro-composite material according to claims 1 and 2, characterized in that the micro-composite material is insoluble in organic solvents as nanoparticles Contains stimulator of polymer crystallite formation. 27. Micro-composite material according to claim 1 and 2, characterized in that the micro-composite material prefers water-soluble plasticizers Contains esters of citric acid. 28. Micro-composite material according to claims 1, 2 and 22, characterized in that that the cast film is used as a wound covering. 29. Micro-composite material according to claims 1, 2 and 22, characterized in that that the material is used as a cast film for the cultivation of skin cells. 30. Micro-composite material according to claims 1, 2 and 22, characterized in that that the material macro pores with a diameter between 10 microns and 1000 µm. 31. Micro-composite material according to claims 1, 2 and 22, characterized in that that macropores by piercing with a tool or with the help of Laser technology can be manufactured. 32. Micro-composite material according to claims 1, 2 and 22, characterized in that that the cast film macropores in the form of slots with a length between 0.5 mm to 10 mm. 33. micro-composite material according to claims 1, 2 and 22, characterized in that that the slots through incisions with cutting tools or with the help of laser technology. 34. Micro-composite material according to claims 1 and 2, characterized in that the materials by precipitating the suspensions in ethanol and / or Ethanol / water mixtures can be produced. 35. Micro-composite material according to claims 1, 2 and 22, characterized in that that membranes for the separation of tissue have pores smaller than 1 µm. 36. Micro-composite material according to claims 1 and 2, characterized in that textile vascular prostheses in a suspension consisting of those in one organic solvent dissolved material components are immersed in the adhering film then dried and the process, if necessary, several times is repeated. 37. micro-composite material according to claim 1 and 2, characterized in that Ephitel cells, endothelial cells, Langerhans islet cells, liver cells, skin cells or dividing cells of the hair root or Kerationozyten in the pores and / or cultivated on the material surface.