DE102009037479A1 - Process for the preparation of a biocompatible and biodegradable composite material, the composite material available thereafter and its use as a medical device - Google Patents

Abstract

A method is described for producing a biocompatible and biodegradable composite material that can be used as a medical device, whereby a) a hydrogel is provided, which contains at least one synthetic polymer and at least one natural polymer, b) an electric field is applied to the hydrogel, c) one Structuring of the hydrogel is induced, in particular with the formation of pores in the hydrogel, d) the hydrogel is subjected to a drying measure and e) the dried hydrogel is sterilized and cross-linked by chemical and / or physical measures to form the composite material. Also described is a composite material which can be obtained by this process and in particular has pores and / or pore channels into which substances which promote cell growth, cell colonization and / or cell adhesion can be introduced. This also results in an advantageous application of the composite material as a carrier for biological cells, in particular human, animal or plant cells, and as a tissue replacement in the human or animal body.

Description

The invention relates to a method for producing a compatible and biodegradable composite material which can be used as a medical device, to a composite material which can be obtained by this method, and to its use as a carrier for biological cells and as tissue replacement in the human or animal body. In this regard, the state of the art according to the WO 2005/044325 A1 directed.

in the medical field are becoming increasingly synthetic tissue carriers needed as a replacement for organs and tissues. This Domain is commonly referred to as tissue engineering. Of special Significance are tissue carriers that interact with the native organ or tissue in the biological, biochemical, biomechanical and structural characteristics are largely identical. For reconstructive and regenerative medicine, traumatology and orthopedics have been tissue carriers in recent years in the musculoskeletal area (replacement for bones, cartilage and tendons) has become particularly significant. The properties of currently available carriers correspond in many ways Not the native tissue, as often the natural one Morphology is not replicated and / or biochemical and / or Biomechanical properties do not match.

For Repair of osteochondral defects introduces tissue engineering a promising therapeutic approach dar introduced with a potential for cartilage formation in porous support materials and then directly or after in vitro precultivation in the chondral Defect used in vivo. Such carrier materials must have specific material properties for their use, especially with regard to dimensional stability, delayed Degradation, biocompatibility, cell adherence, chondrocontrol activity, fulfill. Of special medical and economic Meaning is the area of joint disease. In this area The most painful diseases are those that have cartilage and the underlying bone structure is destroyed. Cartilage has limited ability for regeneration and then usually has a lower quality on as the healthy cartilage. Numerous attempts have been made to transplant healthy cartilage and subchondral bone tissue or to keep in culture; however, so far no way in this way successful replacement.

In order to successfully use synthetic materials as cartilage replacement, many different properties of the natural system must be taken into account. These include biochemical composition, structural identity (mimicking zonal morphology) and biomechanical properties. As synthetic materials, porous foams based on natural and synthetic polymers of various authors have been proposed. A good overview of the technologies for the production of porous materials for tissue engineering is provided by Mikos et al., Electronic Journal of Biotechnology, Vol. 2, 2000 shown. The authors describe several methods for producing highly porous lattice structures. For example, lattice structures are created by forming a three-dimensional network of fibers of polyglycolic acid ("fiber bonding").

A certain progress compared to the state described above is the technical teaching, resulting from the WO 2005/044325 A1 results. This WO document discloses a method for producing a composite material from a natural polymer and an inorganic component, in particular calcium phosphate, which is intended to mimic the bone / cartilage transition. The preparation is based on a hydrogel containing at least one other component such as calcium carbonate or phosphate, which precipitates upon application of an electric field to the hydrogel or forms a solid phase. Subsequently, an electric field is applied to the hydrogel and structuring, in particular pore formation, induced in the hydrogel.

This The state of the art is understood by the term "hydrogel" Water-containing gel based on hydrophilic molecules, in particular polymers which are present as three-dimensional networks. In water, these networks swell under extensive conservation of form up to an equilibrium volume. The networking in water occurs mainly via chemical linkage the individual polymer chains, but is also physically by electrostatic, hydrophobic and / or dipole / dipole interactions between individual Segments of molecular chains possible. One after this composite obtained composite material is suitable as cartilage replacement, However, in order to improve the in vivo stability, it must be dried and chemically and / or thermally crosslinked. Optionally in addition, cell growth or cell colonization or cell adhesion promoting substance introduced become.

It has been found that the prior art last described is very satisfactory. However, it would be desirable if there was a possibility of stability in a suitable and advantageous manner in order to be able to tailor the in-vivo stability of the product to the intended use. Here is an object of the invention below. In addition, the composite material described later should be biocompatible and biodegradable in the broadest sense, so that a largely unrestricted possibility of use as a medical device is given. For this purpose, the composite material should have a near-natural tissue morphology and show an excellent match with native tissue, therefore be sufficiently biocompatible, and have the required biomechanical and biochemical properties. In particular, it should be suitable to mimic the zonal morphology of natural tissue material, in particular cartilage / bone tissue, in an excellent manner. The invention is also intended to suggest a particularly suitable method for producing such an advantageous medical device. Furthermore, advantageous possibilities of using such a composite material are to be proposed.

The The above object is achieved by a method for Production of a biocompatible medical device and biodegradable composite material characterized is that a) a hydrogel containing at least one synthetic polymer and at least one natural polymer is provided b) an electric field is applied to the hydrogel, c) a structuring of the hydrogel is induced, in particular under Formation of pores in the hydrogel, d) the hydrogel of a drying measure and e) the dried hydrogel by chemical and / or physical measures to form the composite material sterilized and crosslinked. Advantageous embodiments of the methodology result from the subclaims presented below 2 to 22.

object The invention is further a composite material, which after the Process of claims 1 to 22 is available. The following subclaims 24 to 30 relate to advantageous embodiments of the invention Composite material.

Further is attributable to the present invention complex the use of the designated composite material as a carrier for biological cells, in particular for human, animal or plant cells, or as a tissue replacement in the human or animal body.

The invention will be described in detail below:
The starting point of the invention according to the above-described measure a) is a hydrogel. What is meant by this in the context of the invention has already been described in connection with the prior art according to the WO 2005/044325 discussed what was referred to. In order to avoid extensive repetition, the statements made there are expressly to be regarded as a disclosure of the present invention. Furthermore, the term "gel" should also be mentioned: "Gels", as they are mentioned in the prior art and can also be used in connection with the invention described below, are dimensionally stable, easily deformable, of liquids and / or gases to understand rich disperse systems of at least two components, which consist mostly of a solid, colloid-divided substance with long or highly branched particles and a liquid (usually water) as a dispersant. As a rule, it is a solid, coherent substance which forms a spatial network in the dispersion medium. The particles adhere to one another at different points due to secondary or major valences. From "gels" in general, "hydrogels" are derived from "xerogels". These are to be understood as gels which have lost their fluid in some way, in particular by evaporation, squeezing or suction, whereby the spatial arrangement of the net may also change, so that the distances between the structural elements have different dimensions than in the hydrogel.

In light of the foregoing illustrations of the terminus "hydrogel", the present invention is to be understood as meaning that the hydrogel not only includes at least one natural polymer but also contains at least one synthetic polymer. One of ordinary skill in the art will provide this hydrogel of synthetic polymer and natural polymer. Thus, for example, he can pre-mix the synthetic polymer and the natural polymer in a suitable manner, and then by adding water, for example according to the specifications of WO 2005/044325 to make the hydrogel.

An advantageous embodiment of the method according to the invention is that in the described measure a) the hydrogel is provided by the at least one synthetic polymer and the at least one natural polymer at a suitable temperature, in particular in the temperature range from about 30 ° C to 100 ° C, preferably from about 40 ° C to 70 ° C and especially from about 50 ° C to 65 ° C, are dissolved or mixed in water and the mixture is then cooled until the gel state sets. In the practice of the present invention, it has proven to be expedient if polyglycolic acid, comonomers of lactic acid and glycolic acid are used as the synthetic polymer re, poly-ε-caprolactone, poly (β-hydroxybutyrate), poly (p-dioxanone). and / or polyanhydrides are used. The synthetic polymer can advantageously be used as a powder or granules and, in particular, is a powder dispersible homogeneously in an aqueous phase by milling / mixing processes.

Independently Of the above-described synthetic polymers, they can be unlimited and advantageously the following substances as a natural polymer can be used: proteins, especially collagen, gelatin, fibrin, Fibrinogen, albumin, silk proteins and / or casein and / or polysaccharides, in particular chitin, chitosan, cellulose and / or alginates.

The skilled person is free to select from the groups of the designated synthetic and / or natural polymers for the particular application, the appropriate combination. It has proved to be particularly advantageous if polylactide-co-glycolide is used as the synthetic polymer and gelatin as the natural polymer. Here, the skilled person will suitably determine the appropriate degree of polymerization or other essential properties. Thus, it has been shown that a gel strength of the gelatin used according to Bloom ( DIN EN ISO 9665 ) of about 20 to 450 g, especially about 250 to 300 g is particularly advantageous.

The advantageous weight ratio between that for the production of the hydrogel used synthetic polymer and natural Polymer may, depending on the contemplated use of the finished composite material be determined. It is preferred if on a part by weight synthetic polymer about 1 to 10, especially about 4 to 6 parts by weight natural polymer can be used.

In accordance with the prior art described above WO 2005/044325 A1 follows the described measure a), after which the hydrogel is prepared, the treatment according to measure b). In this case, an electric field is applied to the hydrogel. It is advantageous if a voltage of about 1 to 50 volts, in particular 25 to 30 volts applied to the hydrogel and / or a current flow of the strength of about 0.5 to 5 A is set by the hydrogel. The time frame for this is not critical. It is expedient if the measure b) is carried out over a period of about 1/2 minute to about 120 minutes. The previously designated voltage may be due to a DC voltage or an AC voltage. In an advantageous embodiment, an alternating voltage with a frequency of about 0.01 to 1 hertz, preferably about 0.05 to 0.1 hertz applied. The application of an electric field to the hydrogel used in accordance with the invention can be effected via electrodes of a type known per se. In a preferred embodiment, two electrodes are used which are positioned on opposite sides of the hydrogel and in electrically conductive connection therewith.

The both above measures a) and b) concludes a measure c), in which a structuring of the Hydrogels is induced, in particular to form pores, including pore channels. It is the expert taking into account the initially described state It is well known in the art how to create a structuring can. In particular, it is the measure of Freezing the hydrogel. The freezing measure preferably takes place of the hydrogel in a directional way, so that the training of cellular and / or dendritic structured ice crystals, and / or in a way governed by physical laws in solidification water-containing substances is given. The freezing step can also undirected. An example of an undirected one Freezing is a very fast solidification (shock freezing process), for example over a period of about 1 s-180 s, preferably from about 50 to 70 s, resulting in an amorphous vitreous Condition of the hydrogel leads.

In In some cases, it is advantageous if the ones described above Measures b) and c) performed superimposed over time become. The measures b) and c) can be timed coincide, but also separated one after the other or be carried out so that one of the two measures after the start of each other's action will be completed without the other measure being completed is.

It may also be appropriate if the hydrogel before the implementation of measures b) and / or c) is formed as a layer, which then the measures b) and / or c). This layer can after performing of measures b) and c) of the procedure.

The measures a) to c) described above are followed by a drying measure d). Here, too, can be proceeded purely expert, for example, can be adjusted by purging with air the required degree of drying. It has proven to be particularly advantageous if the drying measure d) is carried out in the form of a freeze-drying. It has been shown that the freeze-drying expediently a freezing of the hydrogel at a temperature of about -1 ° C to -196 ° C, esp In the range of about -10 ° C to -100 ° C, in particular, which takes place during a period of about 30 minutes to about 4 hours. After the material is largely frozen, then joins the freeze-drying. This is usually about 1 to 7 days, especially about 2 to 4 days. It is well known to those skilled in the art that freeze-drying always takes place by sublimation of the volatile constituents.

Around According to the invention for the described Application is to provide suitable composite material, is it is necessary to carry out the designated action (e). The dried hydrogel should by chemical and / or physical Measures sterilized and networked. The respectively set degree of crosslinking determined in the various applications the desired stability. It is, however, advantageous if the networking and sterilization at least overlapping or in particular at the same time. The majority of the following described measures provides this advantageous embodiment the invention safe. So it is in any case advantageous if the measure e) not only to the desired networking, but also leads to the required sterilization. This can be guaranteed if the measure e) is a dry heat treatment, which at a temperature of more than about 130 ° C takes place. Especially it is preferred that the dry heat treatment at a temperature of more than about 140 ° C and / or less than about 200 ° C performed becomes. The duration of the dry heat treatment has an influence on the degree of sterilization and networking. In general it is preferred if the dry heat treatment during a Duration of at least about 8 hours, in particular of at least about 24 hours, is performed. Here are also heat resistant pathogens are desirably killed.

A Another particularly advantageous embodiment of the measure e) for sterilization and crosslinking is to let act ionizing radiation, in particular UV rays, X-rays, gamma rays and / or electron / ion beams. In this case, the appropriate radiation intensity is expertly adjustable, as these also have an effect on the achieved degree sterilization and networking. In individual cases it may be appropriate, the designated measure e) to perform chemical sterilization and crosslinking. This can be done in particular by treatment with an aldehyde and / or ketone take place, in particular with formaldehyde. It may also be appropriate be the measure e) in the form of a combination of a chemical treatment and. a treatment with ionizing radiation make. With the chemical treatment is to be considered that remain in the crosslinked material toxic impurities can. This generally makes a subsequent action the removal of such impurities required. This can for example, in the case of the use of formaldehyde as a chemical Crosslinking agent carried out by subsequently several times with sterile saline (for example, about 1%) is washed to the aldehyde residues from the dried hydrogel to remove.

Of the The expert readily recognizes that the addressed networking within at least one polymer component to form covalent bonds between individual polymer molecules leads. It is beneficial if networking not only within the individual Polymer components takes place, but also between the different Polymer components. These can be synthetic and natural Polymers are formulated so that such crosslinking is possible. For example, both polymers carry the above referred to as beneficial combination of gelatin and polylactide-co-glycolide reactive groups resulting in the formation of ester and / or amide linkages can react. A crosslinking within the polymer components is by no means absolutely necessary. So one can not react Component, for example, by forming a melt phase at a thermal process step, to stabilize the composite material contribute. Of particular advantage is when the second component both as a reacting component and as an unresponsive one Component contributes to the stabilization of the composite material.

In Individual cases, it may be appropriate if the material resulting from measure d) is removed before the Process step e) is packaged and sealed and it during the implementation of the process step e) in the packaging remains. This has the advantage of a contamination of the material can be avoided in a later step.

Finally, the method according to the invention, also with regard to the desired process product in the form of the designated composite material, can be advantageously controlled by the fact that, in accordance with the disclosure of US Pat WO 2005/044325 A , a hydrogel according to measure a) is provided which contains an inorganic constituent which precipitates upon application of the electric field after the measure b) and forms a solid phase. There is no significant restriction here. Is required it alone that this additional component precipitates upon application of an electric field to the hydrogel or forms a solid phase. In particular, the following can be considered as inorganic constituents: calcium carbonate, calcium phosphate, in particular hydroxylapatite, tricalcium phosphate, brushite, octacalcium phosphate, amorphous calcium phosphate, tetracalcium phosphate, monetit, calcium-deficient hydroxylapatite and / or fluorine-containing calcium salt, in particular fluorinated hydroxyapatite.

Next The components described above may have more Components for forming the composite material come into question, if any special property by the inclusion of such Ingredient in the finished product. So It may be advantageous in individual cases, if at the Implementation of the method according to the invention a component is included that is electrically conductive is. Should such an ingredient be included, it could also this when applying an electric field to the hydrogel fail and form a solid phase.

The The other ingredients should be in the ultimately networked and sterilized hydrogel in the form of the composite material as possible be distributed homogeneously. In some cases disturbs one inhomogeneous distribution not.

As already stated, the invention is also a Composite material made in accordance with the above described in detail in accordance with the Invention is available. The structuring of the into the Composite material of overgrown hydrogel turns out in particular in that the composite material pores and / or channels or having pore channels. It is preferred, at a bonded crystalline and / or amorphous solid phase. At a preferred embodiment of the invention is in the designated crystalline and / or amorphous solid phase to a calcium compound, as mentioned above.

Of the Diameter of the designated pores or pore channels not critical. Advantageously the diameter of the pores or channels is about 50 to 500 μm, in particular 150 to 300 microns. If here of "pore size" in the Connection with the pore channels or channels is spoken, then below the mean pore channel diameter be understood.

Around to fulfill the overall purpose of the invention, namely, the composite material prepared in the above manner to use according to the invention as a medical device, The composite material can be used without further modifications become. It is useful if the composite material according to the invention in its pores and / or channels respectively.

pore channels cell growth, cell colonization and / or cell adhesion contains promotional substance. The inclusion of such Substances are advantageously carried out as follows: The substance to be introduced is dissolved in a suitable solvent or dispersed. With this solution, the dry composite material, having the pore or channel structure, impregnated. Subsequently a freeze-drying of the impregnated composite material, so that the introduced substance remains in the composite material.

It it is preferred that the at least one of cell growth, cell colonization and / or the cell adhesion promoting substance a growth factor or human or animal blood serum serum produced, preferably one produced from animal blood serum Serum, in particular serum derived from calf blood, or poly-L-lysine. The growth factor will be particular derived from substances of the TGF-β superfamily, in particular TGF-β1, existing group selected. Of special Advantage is it, if the at least one the cell growth, the Zellansiedlung and / or the cell adhesion promoting substance is a serum is, in particular, autogenic, synergenic, allogenic or xenogeneic Origin. Furthermore, it is advantageous if the inventive Composite material biological cells, especially human, animal and / or vegetable cells.

The above detailed according to the invention Composite material is, the task initially stated as Carriers for biological cells, in particular human, animal or plant cells, suitable. Here can be as specifically designate preferred cells: cartilage cells, bone cells, Cells of the blood system, skin and nerve tissue.

Of particular advantage is the use of the composite material according to the invention as a tissue replacement in the human or animal body. Tissue replacement particularly includes the applications for the healing of defects in the area of the articular cartilage, the bone, the skin and the nerve tissue. In particular, the described material is suitable for supporting cartilage formation in vivo and in vitro and may be used to advantage in mosaic sculptures on the knee, hip and / or meniscus. Furthermore, the described material, optionally in combination with a plaster, can advantageously be used as hemostatic material. It is expedient if collagen is used as the natural polymer because it is not decomposed sour like other products.

It Thus, it turns out that the invention, as described above in various Embodiments is presented, the task set dissolves in an excellent way. The case in particular highlighted stabilization, adapted to the respective application, is desirable to control. This is especially true on the additionally contained in the starting hydrogel synthetic Polymer back. Not just the synthetic polymer as such an influence, but also, as can be readily seen, the chosen ratio between the natural and synthetic polymer. Other ways of controlling the desired for the particular application Properties of the composite material are that, in particular the explained further ingredient in the form of an organic Materials can be used. This has the following advantages: Combination of a natural material component with optimal on the defect to be cured already existing properties with one synthetic material component with very selectively adjustable Property profile in terms of degradation rate and mechanical stability.

The Invention will be described below with reference to a detailed example be explained.

example 1

1. Preparation of a homogeneous gelatin-polylactide-co-glycolide (PLGA) solution

For Eight composite materials (scaffolds / samples) are each about 5 ml solution needed. 1. Preparation of the solution: This solution should contain per ml: 0.05 g of gelatin (50% w / v), 0.01 g of PLGA R503H (sold by Boehringer, Ingelheim, Germany), (1% w / v) and 1.0 ml of water. in this connection Specifically, the procedure is as follows: gelatin on weighing paper Weigh and place in a closable 50 ml tube. Pipette water and container to swell Place gelatine in a shaker for 10 minutes. Falcon for Place in the 60 ° C water bath for 10-15 minutes, until the gelatin is dissolved. Weigh PLGA on weighing paper and put in a mortar. 2-5 ml gelatin solution Add and mortar until the PLGA is very finely distributed (at least 10 minutes). The solution in the mortar eventually Heat in a water bath and transfer to a new one with the 1 ml pipette Pipette the sealable container. The Tube several times for about 5 sec in an ultrasonic bath hold. Shake or vortex in between. The finished one Solution as needed in a water bath at about 40 ° C warm up (but not above 50 ° C). The lockable container dry well, Wipe with isopropanol and back into the shaker put.

2. Freeze the scaffolds

One forming vessel (sample form) consisting of a shaping silicone lid, a metal plate and two platinum electrodes is provided and connected to suitable temperature sensors. The electrolysis voltage is set to 20 V. The sample form is subsequently mixed with the gelatin-PLGA solution so filled that a contact with both platinum electrode exists and allows electrolysis. To freeze will a Peltier element is used on which the sample mold rests. The Temperature is set to -5.5 ° C. After that The temperature is reduced so that a cooling with 0.1-0.3 ° C / min is achieved. It becomes the electrolysis voltage turned off and the anode removed. After complete Freezing the samples becomes the sample shape of the Peltier element away. The samples are carefully detached from the sample mold and for at least 4 hours in a freezer (-80 ° C) in suitable Teflon vessels stored.

3. Freeze-drying

The Teflon tubes are removed from the freezer taken and covered with autoclaving paper, sealed and in a freeze drier (Modulyo, BOC Edwards, United Kingdom) freeze-dried for at least 3 days.

4. Sterilization and cross-linking of scaffolds

The Scaffolds are cut with a suitable knife in about 8 × 2 mm large cylinder cut and then double welded in a hot air sterilization bag. The bags are kept at a temperature of 140 ° C for 24 hours networked and laid in a drying oven. This treatment leads to the desired sterilization and crosslinking.

Example 2 (introduction of cell growth, promote cell colonization and / or cell adhesion Substance)

Poly-L-lysine is crushed together with PLGA and as in Example 1 further processed together with the gelatin solution. By the high melting point of poly-L-lysine (about 170 ° C) and the even higher decomposition temperature of the lysine monomer, is assumed to have a significant residual activity.

Example 3 (detection of non-toxicity gelatin and gelatin-PLGA based composite material)

• Anmerkung: Die Tabelle entspricht 1

A composite prepared according to Example 1 was tested for cytotoxicity with specialized cells in an external, certified and accredited testing laboratory (Neutral Red Test). As a comparison, negative controls and positive controls were used. The reduction of cell vitality is in the range of the requirements of the DIN EN ISO 10993-5 , The results of the external testing are in 1 and Table 1. Table 1 Optical density (mean) Cell Vitality (Percent) Normalized to Negative Control Negative control (n = 9) 1,194 ± 0.035 100 Positive control (n = 9) 0.054 ± 0.004 4.56 Invention (n = 12) 0.999 ± 0.029 83,64

• Note: The table is equivalent 1

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2005/044325 A1 [0001, 0005, 0017]
• WO 2005/044325 [0011, 0012]
• WO 2005/044325 A [0026]

Cited non-patent literature

• Mikos et al., Electronic Journal of Biotechnology, Vol. 2, 2000 [0004]
• - DIN EN ISO 9665 [0015]
• - DIN EN ISO 10993-5 [0043]

Claims (32)

A method for producing a biocompatible and biodegradable composite material useful as a medical device, characterized by providing a) a hydrogel containing at least one synthetic polymer and at least one natural polymer, b) applying an electric field to the hydrogel, c) a Structuring of the hydrogel is induced, in particular to form pores in the hydrogel, d) the hydrogel is subjected to a drying measure and e) the dried hydrogel is sterilized and crosslinked by chemical and / or physical measures to form the composite material. Method according to claim 1, characterized in that in that measure a) provides the hydrogel thereby is that the at least one synthetic polymer and the at least a natural polymer at a suitable temperature in water be dissolved or mixed and then cooled so far until a gel state sets. Method according to claim 1 or 2, characterized that as a synthetic polymer polyglycolic acid, comonomers lactic acid and glycolic acid, poly-ε-caprolactone, Poly (β-hydroxybutyrate), poly (p-dioxanone) and / or polyanhydrides, in particular in the form of powders or granules. Method according to claim 3, characterized that the synthetic polymer used as a powder or granules is, in particular as a by grinding / mixing processes homogeneous in an aqueous. Phase dispersible powder. Method according to one of claims 1 to 3, characterized in that as natural polymer proteins, especially collagen, gelatin, fibrin, fibrinogen, albumin, silk proteins, and / or casein and / or polysaccharides, in particular chitin, chitosan, Cellulose and / or alginates, are used. Method according to at least one claims 1 to 4, characterized in that as a synthetic polymer Polylactide-co-glycolide and as a natural polymer gelatin be used. Method according to claim 5, characterized in that the gel strength of the gelatin according to Bloom (DIN EN ISO 9665) about 20 to 450 g, in particular about 250 to 300 g. Method according to at least one of the preceding Claims, characterized in that on a part by weight synthetic polymer about 1 to 10, especially about 4 to 6 parts by weight natural polymer can be used. Method according to at least one of the preceding Claims, characterized in that in measure b) a voltage of 1 to 50 volts, in particular about 25 to 30 Volt, is applied to the hydrogel, in particular over a period of about half a minute to about 120 minutes. Method according to at least one of the preceding Claims, characterized in that the measure c) carried out by a freezing process of the hydrogel becomes. Method according to at least one of the preceding Claims, characterized in that the measures b) and c) are superimposed. Method according to at least one of the preceding Claims, characterized in that the drying measure d) is a freeze-drying. Method according to claim 12, characterized in that that freeze-drying by freezing the hydrogel in a Temperature of about -1 ° C to -196 ° C, especially during a period of about 30 minutes up to about 4 hours, followed by sublimation becomes. Method according to at least one of the preceding claims, characterized in that in the measure e) the sterilization and crosslinking are carried out simultaneously, in particular by a dry heat treatment at a temperature greater than about 130 ° C. Method according to claim 14, characterized in that that the dry heat treatment at a temperature of more than about 140 ° C and / or less than about 200 ° C performed becomes. Method according to claim 14 or 15, characterized that the dry heat treatment during a period of time of at least about 8 hours, especially at least about 24 hours, is performed. Method according to at least one of the claims 1 to 13, characterized in that the sterilizing and crosslinking in the case of measure e) with ionizing radiation, in particular with UV rays, X-rays, gamma rays and / or Electron / ion beams is performed. Method according to at least one of the claims 1 to 13, characterized in that in the measure e) the sterilization and crosslinking are carried out chemically be, in particular by treatment with an aldehyde and / or Ketone. Method according to at least one of the claims 1 to 13, 17 and 18, characterized in that in the measures e) a chemical treatment and treatment with ionizing Steel is performed. Method according to at least one of the preceding Claims, characterized in that the composite material before process step e) is packed and sealed and during the implementation of the process step e) in the packaging remains. Method according to at least one of the preceding Claims, characterized in that a hydrogel after the measure a) is provided, which is an inorganic Component contains, when applying the electric field after the measure b) fails and a solid phase forms. Method according to claim 21, characterized that the inorganic constituent is selected from the group of calcium salts, in particular of calcium carbonate, calcium phosphate, in particular Hydroxyapatite, tri-calcium phosphate, brushite, octacalcium phosphate, amorphous calcium phosphate, tetracalcium phosphate, monetite and / or Calcium-deficient hydroxyapatite, containing fluorine Calcium salt, in particular fluorinated hydroxyapatite existing Group is selected. Composite material made by a process according to at least one of the preceding claims. Composite material according to claim 23, characterized that it has pores and / or channels, in particular a crystalline and / or amorphous solid phase is bound. Composite material according to one of the claims 23 or 24, characterized in that the pores or the channels a diameter of about 50 to 500 microns, in particular about 150 to 300 microns, have. Composite material according to at least one of the claims 23 to 25, characterized in that the crystalline and / or amorphous solid phase based on a calcium phosphate. Composite material according to at least one of the claims 23 to 26, characterized in that it is in the pores or channels cell growth, cell colonization and / or cell adhesion contains promotional substance. Composite material according to claim 27, characterized that the at least one cell growth or cell colonization or the cell adhesion promoting substance is a growth factor or a serum produced from human or animal blood serum, in particular a serum produced from calf blood, or poly-L-lysine is, the growth factor in particular from the substances the TGF-β superfamily, especially TGF-β1, existing Group is selected. Composite material according to claim 28, characterized in that that at least one of cell growth, cell colonization and / or the cell adhesion promoting substance is serum, in particular autogenic, synergenic, allogeneic or xenogeneic origin. Composite material according to at least one of the claims 23 to 29, characterized in that it further includes biological cells, in particular human, animal and / or plant cells contains. Use of a composite material after at least one of claims 23 to 30 as a carrier for biological Cells, especially human, animal or plant cells. Use of a composite material after at least one of claims 23 to 30 as a tissue replacement in the human or animal body.

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