Porous microspheres of calcium and magnesium biophosphate with adjusted particle size for bone tissue regeneration
SUBSTANCE: invention refers to porous microsphere granules with the adjusted particle size for bone tissue regeneration. The above microspheres have a size within the range of 1-1000 mcm, have through pores of the size of 1-100 mcm and total porosity 40-75%. The declared microsphere granules are prepared by granulation by electrospinning, and heat-treated. A mixture used to form the granules by electrospinning contains a mixture of magnesium orthophosphate and biological hydroxyapatite of bovine demineralised bones in ratio 0.5:1.0, as well as 1-3% sodium alginate in distilled water and a hardener representing saturated calcium chloride.
EFFECT: invention provides preparing the microsphere granules possessing biocompatibility, biodegradation, osteoinduction and osteoconduction properties and able to be substituted by the bone tissue.
The invention relates to the field biophosphate ceramic materials for medicine, namely to traumatology, orthopedics, reconstructive surgery, cosmetology, dentistry and to the system of drug delivery.
Calcium phosphates are the main elements of the bone and are widely used as materials for bone regeneration and production of solid bone implants used in orthopedic, maxillofacial surgery, etc. To the most used in medicine to calcium phosphates include tricalcium phosphate - CA3(PO4)2(TCP) and hydroxyapatite - CA5(PO4)3HE (HA) or bi-phase materials based on the system TKF-HA. Biological and mechanical properties of calcium phosphate ceramics are determined by the phase composition and structure, which mainly depend on the firing temperature and the size of the original particles of the ceramic powder. One method to improve mechanical properties and reduce the sintering temperature of ceramics is the use of ceramic ultrafine powders with a particle size less than 1 micron.
(A. Tampieri, G. Celotti, F. Szontagh and Landi "Sistering and characterization of HA and TCP bioceramics with control of their strebght and phase purity". J. of Materials in Medicine 8 (1997 29-37) were obtained calcium phosphate materials based on TCP and HA powders with cf who ne the crystal size of 0.5 μm. The obtained materials were characterized by a crystalline structure with an average crystal size of 1-2 microns, a porosity of less than 7%. The disadvantage of this material was high firing temperature 1220-1300°C. in Addition, at temperatures above 1250°C, the decrease of the strength and partial decomposition of HA with the formation of toxic calcium oxide.
Also known calcium phosphate-based materials system tricalcium phosphate-hydroxyapatite (S. Raynaud, E. Champion, D. Bemache-Assollant "Calcium phosphate appatites with variable Ca/P atomic ratio is 2. Calcination and sistering", Biomaterials 23 (2002) 1073-1080)obtained by sintering of nanocrystalline powders at a temperature of 1100-1150°C. In this work to reduce the sintering temperature managed through the use of nanocrystalline powders and method of hot pressing. This has resulted in bi-phase materials system TKF-HA, which was characterized by a fine structure with an average crystal 200 nm. The disadvantage of this pottery is a high firing temperature and the application of the method of hot pressing, resulting in a considerable rise in prices of finished products.
From RU 2359708, 27.06.2009 other known calcium phosphate ceramic material intended for the manufacture of bone implants and/or replacement of defects in various bone pathologies.
Material sostoi is from tricalcium phosphate-hydroxiapatite ceramics with additives of potassium carbonate, and/or lithium carbonate, or calcium carbonate in the following ratio of components in ceramics, wt.%:
|hydroxyapatite and/or tricalcium phosphate||- 80-99,5|
|one of the above additives||of 0.5 to 20.0|
Known ceramic material has a particle size of not more than 100 nm and the porosity (open) less than 4% after annealing up to 700°C.
The material does not have the necessary osteoinductive and osteoconductive properties.
It is known that the magnesium phosphate is included in the composition of bone tissue. Magnesium acts as a regulator of cell growth that is necessary at all stages of the synthesis of protein molecules. Magnesium is an essential element of the triad CA, P, Mg, currency are closely interrelated. He takes part in the metabolism of phosphorus, energy metabolism, synthesis of the enzyme, metabolism of carbohydrates, regulates glycolysis, involved in the construction of bone tissue, providing functional capacity of the nervous and muscular tissues.
Like calcium, it takes part in many metabolic processes. The enzymes in the composition of the active catalytic center which includes magnesium ion plays an important role in providing energy to the body, the transport of various substances through cell membranes, synthesis be the Cove and nucleic acids. Magnesium plays an important role in osteogenesis, can directly affect the function of bone cells.
From RU 2292868, 10.02.2007 known material for filling bone maxillofacial and dental defects. The material is made on the basis of the reaction-hardening mixture of powders, contains hydroxyapatite and tricalcium phosphate, as shuts the fluid used in the solution of magnesium phosphate and phosphate in phosphoric acid at a certain quantitative content of them shuts the liquid, the quantity shuts fluid to the number of reaction-hardening mixture is 0,25-0,65. Budget source components and high strength allow a wide use of this material for the correlation of the fragments of the alveolar ridge, closing cavities in the bone tissues and treatment of various traumatic fractures of Genesis.
Known material has limited use and does not provide all the necessary properties, namely the necessary biocompatibility, biodegradation, necessary osteoinductive and osteoconductive properties.
It can be selected as the closest analogue to the total number of similar features.
The technical purpose of this invention to provide a material in the form of microspheres granules based biophosphate the calcium and magnesium with adjustable particle size, possessing biocompatibility by biodegradation, osteoinductive and osteoconductive properties, is able to completely replaced by bone tissue.
The goal of the project and achieved technical result is achieved by a porous granules microspheres with controlled particle size for the regeneration of bone tissue and is characterized by the fact that have a size in the range of 1-1000 μm, the through pores of a size of 1-100 microns and a total porosity of 40-75%, granular method of electrospinning, heat treated and obtained from a mixture containing a powder of magnesium orthophosphate and biological hydroxyapatite powder from demineralized bone of cattle at a ratio of 0.5-1.0, and 1-3%solution in distilled water of sodium alginate to obtain a plastic mass, the ratio of powder, liquid phase and hardener, a saturated solution of calcium chloride, 0.5 to 1.5:2-5:5-20, respectively.
According to the prior art it was found that interaction of calcium and magnesium will be optimal when the ratio in the body 1:0,5-0,7 respectively. Otherwise, the calcium will interfere with the absorption of magnesium. Therefore, we chose the ratio of powder orthophosphate magnesium and biological hydroxyapatite 0.5 to 1.0. These ratios are optimal. Below these values the resulting mixture of orthophosphate mage is Oia, hydroxyapatite adding a solution of sodium alginate is very liquid and the time to expiration of the needle when the applied voltage is so fast that the granules do not have time to form. Above these values the resulting mixture is so viscous that it cannot be pushed through the needle.
The heat treatment of the pellets within 60 minutes at a temperature of 850°C. Using the method of electrospinning to obtain pellets allows to produce very small particles of biophosphates, changing the applied voltage.
Electrospinning at the moment can be called the most advanced and fastest way to obtain granules. Electrospinning is a dispersion of liquid and the formation of granules from a viscous medium under the influence of an electric field. The process is quite simple and does not require high temperatures, which makes it extremely attractive. The essence of the method consists in the following:
To drop viscous solution is applied a high voltage of 15-20 kV, in this case, the liquid acquires a charge, the electrostatic force of repulsion between the molecules begin to counteract the forces of surface tension and the drop is drawn. In this case, selected a certain ratio of sodium alginate and biophosphates on the basis of calcium and magnesium, and also the voltage going to the ILO elektrorazpredelenie fluid. Depending on the applied voltage, it is possible to obtain granules of different sizes. When voltage is less than 15 kV are obtained granules than 1 μm, and the increase in voltage of more than 20 kV impractical from the standpoint of safety and economy. The droplets are sprayed into the tub with a hardener containing a saturated solution of calcium chloride. The obtained granules prokalyvayutsya for 60 minutes at a temperature of 850°C and sieved through sieves to obtain fractions with a specific granule size.
Installation for electrospinning consists of nozzles (syringe needle)connected to the high voltage source, a pump and a grounded collector. The syringe is placed in a liquid: a solution of sodium alginate and biophosphates on the basis of calcium and magnesium; the liquid is then pumped is extruded at a rate of 1 drop per second at the tip of the needle.
The powder used in the invention biological hydroxyapatite obtained as follows. First get biological hydroxyapatite from the bones of cattle by demineralization of bone tissue in 1 M hydrochloric acid solution and subsequent precipitation of hydroxyapatite precipitator, for example 5 M sodium hydroxide solution, filtration, heat treatment at a temperature of 830°C.
The obtained hydroxyapatite is crushed to obtain powder particles of the size of the ROM is not more than 40 μm. This method allows you to obtain a fine powder of hydroxyapatite and trace element composition, as close as possible to the composition of human bone tissue. To enhance osteogenic properties of the material in their composition is administered magnesium orthophosphate.
Powder orthophosphate magnesium is prepared by mixing magnesium oxide and 70% orthophosphoric acid in the ratio of 1:1,18. The resulting orthophosphate magnesium were ground in a ball mill and sifted through a sieve with a mesh size not more than 40 μm. Prepared in this way the orthophosphate magnesium gives the granules plastic properties.
It was established experimentally that the receipt of the particles larger than 40 microns is not possible to enter them through an insulin syringe under the skin or in small bone defects. In addition, particles with a size not more than 40 μm, as is known from the prior art, have high specific surface area of about 80 m2/g, which is one of the key factors of their bioactivity.
Below is a specific example of production of porous microspheres granules of biophosphates calcium and magnesium with adjustable size particles for bone tissue regeneration according to the invention. This example illustrates the invention but does not limit it.
The fractions obtained powders of magnesium orthophosphate and biological hydroxyapatite mixed in zootoxin and 0.5 to 1.0 and mixed in a ball mill for 30 minutes. Then prepare a plastic mass containing 1-3% solution of sodium alginate dissolved in distilled water and the mixture orthophosphate magnesium and biological hydroxyapatite granules are formed by using the method of electrospinning. As the hardener used a saturated solution of calcium chloride. The ratio of components as follows: a mixture of powders of magnesium orthophosphate and biological hydroxyapatite 0,5: a solution of sodium alginate 2; solution of calcium chloride 5.
The fractions obtained powders of magnesium orthophosphate and biological hydroxyapatite mixed in the ratio of 0.5-1.0 and mixed in a ball mill for 30 minutes. Then prepare a plastic mass containing 1-3% solution of sodium alginate dissolved in distilled water and the mixture of powders of magnesium orthophosphate and biological hydroxyapatite granules are formed by using the method of electrospinning. As the hardener used a saturated solution of calcium chloride. The ratio of components as follows: a mixture of powders of biophosphates calcium and magnesium to 1.5: solution of sodium alginate 5: a solution of calcium chloride 20.
So, the method used for electrospinning, namely, the method of electrocapillary fluid at a voltage of 15-20 kV, followed by their capture in the tub with hardener calcium chloride and heat the processing of the granules at a temperature of 830°C.
Grinding the obtained powders is carried out in a ball mill for 30 minutes to obtain a particle size of not more than 40 μm. Such particle size of the powder is optimal for the subsequent process of obtaining microspheres.
The heat treatment of the pellets within 60 minutes. The microspheres contain through-pore size of 1-100 μm, the total porosity of 40-75%.
Used heat treatment temperature sufficient to completely remove the organic component and complete crystallization of the amorphous forms of calcium phosphate compounds and, in addition, necessary and sufficient for the formation of the pore space in the microspheres.
The selected ratio of the components (between calcium phosphate and magnesium phosphate and other components) is necessary for optimal leakage of the fluid through the needle, and get biophosphate microspheres containing the through pores of a certain size.
Formed pore space in the microspheres provides the germination of tissues deep into the pore space.
Based on numerous research on the medical use of ceramic materials is established that biophosphate belong to the class of bioactive materials with surface-active properties and high biocompatibility. The most convenient form for use in medicine are microspheres. For example, the cosmetology with the introduction of the material (because the introduction is insulin syringe, the microspheres should be no more than 30-35 μm) in the dermis of the microspheres of biophosphates stimulate fibroblasts and starts the process of neocollagenesis. In the case of the introduction of microspheres under the periosteum, particles biophosphates stimulate osteoblasts and start the process of osteosynthesis.
The production of granules synthesized hydroxyapatite now well enough developed on a large scale. Obtaining granules of biophosphates calcium and magnesium naturally expects to increase biocompatibility and osteogenic properties.
To study the properties of biocompatibility, biodegradation, as well as the ability to osteoinductive and osteoconductive material studies have been conducted on 20 rats female breed "Wistar" at the age of 3 months. In order to identify systemic reactions of the body of the material was carried out laboratory studies, including the necessary biological indicators were carried out x-ray studies of CT and also prepared and studied histological preparations surrounding the tissue material. Research has conclusively proven that the material has a well-defined biocompatible, biodegradable properties. Furthermore, the material showed high osteoinductive and osteoconductive ability, confirm that the Deno x-ray, histological and biochemical methods.
In addition, there was a higher concentration of calcium in serum, in comparison with the control group of animals that is the most important predictor of successful osteogenesis.
Porous granules-microspheres with controlled particle size for the regeneration of bone tissue, and is characterized by the fact that have a size in the range of 1-1000 μm, have continuous pores with a size of 1-100 microns and a total porosity of 40-75%, granular method of electrospinning and comb, and obtained from a mixture containing a powder of magnesium orthophosphate and biological hydroxyapatite from demineralized bone of cattle at a ratio of 0.5:1.0, and also 1-3%solution of sodium alginate in distilled water to obtain a plastic mass, the ratio of powder, liquid phase and hardener, a saturated solution of calcium chloride as of 0.5-1.5:2-5:5-20, respectively.
SUBSTANCE: invention refers to medicine and tissue engineering, namely to cardiovascular surgery and may be used in coronary artery bypass surgery, as well as in surgical reconstruction of peripheral vessels. What is described is a method for making a porous tubular matrix of a vascular graft of a biodegradable polymer by two-phase electric spinning, with biologically active molecules stimulating the vascular regeneration being incorporated into a matrix wall matrix incorporated biologically active molecules.
EFFECT: creating the tissue-engineered high-patency and durability small-diameter vascular graft for biological re-modelling of the damaged vessels in vivo.
2 cl, 1 ex
SUBSTANCE: invention refers to medicine. What is described is an implanted multilayer chondral reparation flap showing biological compatibility and physiological resorption, and what is also described is a method providing surgical management in situ for intra-articular regeneration of cartilaginous tissue in joint damages and/or defects. The chondral reparation flap comprises a first external cell-impermeable layer and a second external cell-permeable layer adapted for placement in an immediate proximity from a subchondral bone on a wound portion, and also a cartilage-forming matrix located between the first and second layers. The cartilage-forming matrix represents an accepting medium for diffusion of autologous stem cells and contains chemical components promoting formation of a hyaline-like cartilage in the presence of said autologous stem cells. The method prevents a fibrous cartilaginous replacement tissue from forming within the injury region.
EFFECT: method provides autologous compositions which when used in a combination with the reparation flap form the medical system for formation of the replacement hyaline-like intra-articular cartilage.
17 cl, 7 dwg, 1 ex
SUBSTANCE: porous matrix based on biocompatible polymer or polymer mix for tissue engineering is obtained by compression of polymer and sodium chloride particle mix with defined particle size, and further removal of sodium chloride by dissolution. Porosity grade of matrix lies within 93 to 98%, its pores fall into different sizes, with definite pore distribution by size within certain limits.
EFFECT: obtained matrices are free-shaped yet pertain stability and hardness characteristics required to withstand surgical implantation methods and counteract mechanical forces applied at the implantation point.
40 cl, 2 tbl, 8 ex
SUBSTANCE: present group of inventions concerns medicine, more specifically coated implants and devices. There is offered ceramic composition-precursor for making high-strength bio-elements used as an absorbable or partially absorbable biomaterial where the composition contains at least one silicate with Ca as a base cation with the absorption rate less or equal to the bone growth rate, and this at least one silicate acts as a base binding phase in a biomaterial, and this at least one silicate Ca is present in amount 50 wt % or more, and all other components if any are presented by additives, such as an inert phase, and/or additives which make a biomaterial to be radiopaque. There is offered hardened ceramic material which is based on the ceramic composition-precursor and is in the hydrated form. There is offered a medical implant, application of the medical implant, and also a device or a substrate coated with the uncured ceramic composition-precursor and/or hardened ceramic material.
EFFECT: invention provides a biomaterial having initial and constant durability which is dissolved in due time and reacts with an organism to generate a new tissue.
29 cl, 1 ex, 3 tbl
SUBSTANCE: invention relates to field of medicine. Claimed is composition with hyaluronic acid (HA), which includes gel particles of bound water-insoluble hydrated HA. HA includes bindings, represented with the following structural formula: HK'-U-R2-U-TK'. Where each group HA' represents the same or other molecule of bound HA'; each U independently represents optionally substituted 0-acylisourea or N-acylurea; and R2 represents optionally substituted alkyl, alkenyl, alkinyl, alkoxy, cycloalkyl, cycloalkenyl, cycloalkinyl, aryl, heteroaryl, heterocyclic radical, cycloaliphatic alkyl, aralkyl, heteroaralkyl or heterocyclolalkyl. Also claimed is method of developing tissues in individual, including introduction of needle into individual in place where development of tissues is necessary, needle is connected to syringe filled with composition with HA, and applying force to syringe in order to supply composition with HA to individual. Method of obtaining composition with HA includes formation of water-insoluble dehydrated particles of bound HA, separating insoluble in water particles by their average diameter, selection of subset of particles by average diameter and hydration of subset of dehydrated particles by means of physiologically compatible water solution. Other method of obtaining composition with bound HA includes binding precursor of bound HA by means of bis-carbodiimide in presence of pH buffer and dehydration of bound HA. Also included is method of developing tissues in individual that needs tissue development. Method of stabilisation of bound HA includes hydration of water-insoluble dehydrated bound HA by means of physiologically compatible water solution which includes local anesthetic, so that value of elasticity module G' for stabilised composition constitutes not less than approximately 110% from value G' for non-stabilised composition.
EFFECT: claimed composition of hyaluronic acid and method of preparation and application of HA composition are efficient for development of tissue and/or drug delivery.
27 cl, 22 ex, 2 tbl, 7 dwg
SUBSTANCE: effect is achieved by using compositions based on different stereoregular amorphous biodegradable polymers - polylactides and copolymers of lactides with glycolides (18-72 mass ratio) as the second component of biocompatible mineral filler - hydroxyapatite with particle size of the main fraction of 1-12 mcm (8-41 mass ratio), as well as an organic solvent with boiling temperature equal to or higher than softening temperature by 3-20°C (20-41 mass ratio). After preparation of a homogenous mixture, the composition is undergoes thermal treatment at 80-130°C in a vacuum in a shaping vessel with the required shape. A porous product is obtained due to removal of solvent. Density of the obtained porous product is about 0.4-0.8 g/cm3.
EFFECT: design of a method of obtaining porous biodegradable composite polymer products based on polylactides or copolymers of lactides and gylcolides.
3 cl, 3 ex
SUBSTANCE: described are implants based on biodegradable thixotropic compound with pseudo-plastic properties and implant injected under skin or into skin in fibrous tissue. Containing microparticles of at least one biocompatible ceramic compound in suspension, in at least one liquid carrier containing at least one compound based hyaluronic acid and at least one biodegradable thixotropic compound with pseudo-plastic properties. Also disclosed is kit for preparation such implants directly before application, as well as implant production and using for filling of crinkles, and/or skin cavity, and/or cicatrices.
EFFECT: implants of simplified injection.
14 cl, 4 ex
SUBSTANCE: invention relates to medicine, namely to ophthalmosurgery, and in particular to scleroplasty. Transplant for scleroplasty has polymeric base, covered with porous layer of the same polymer. As polymer base, transplant includes layer, made from porous stretched polytetrafluoroethylene, which has nodular-fibrillar structure. As porous layer, it includes layer of porous polytetrafluoroethylene, which has volume fraction of void space 15-40%, specific surface of void space 0.25-0.55 mcm2/mcm3, average distance between voids in volume 25-30 mcm and average chord volume 8-25 mcm, with the total width of transplant constituting 0.15-0.35 mm (first version). Transplant for scleroplasty can also include porous layer of polymer, whose surface is processed to add compatibility with sclera tissue. Transplant surface is processed by application of allogenic dermal fibroblasts of 3-5 passages of culturing, with the total width of transplant being 0.15-0.35 mm (second version).
EFFECT: chemically and biologically inert transplant, which ensures effect of invasion of sclera tissues, is obtained.
SUBSTANCE: invention relates to chemical-pharmaceutical industry and represents artificial dura mater, produced from electrospinning layers by technology of electorspinning, with electrospinning layer, consisting of, at least, hydrophobic electrospining layer, which is produced from one or several hydrophobic polymers, selected from polylatic acid and polycaprolactone.
EFFECT: invention ensures creation of artificial dura mater, which has good tissue compatibility, anti-adhesiveness and possibility of introducing medications, preventing cerebrospinal fluid outflow during regeneration of person's own dura mater.
30 cl, 7 ex, 11 dwg
SUBSTANCE: invention refers to medicine, particularly to ophthalmic and maxillofacial surgery, and aims at repairing post-traumatic defects and deformations of the eye-pit bottom and walls. What is described is an implant in the form of a solid perforated plate which is formed by photocuring of a light curing composition; when heated the implant (a cure temperature 70-90°C) keeps the shape after self-cooling that provides high strength and biocompatible properties of the material. The cure temperature of the material is much higher than a temperature of a human body that ensures maintaining the physical and mechanical properties of the implant inserted in the human body, namely the material remains strong, when fixed it shows no cutting and breaking. Before the implantation, the plate is heated to the required temperature and bent so that it is congruently repeats the eye-pit shape in a place of the defect, overlaps the defect and supports the eye in the right anatomical position.
EFFECT: reducing the likelihood of graft rejection and reducing a quantity of various complications by improving the biocompatible properties of the material.
1 tbl, 5 ex
SUBSTANCE: group of inventions refers to medicine. In a method for making an antimicrobial silver-containing endoprosthesis according to the 1 version, a mesh material is made of synthetic polymer fibres with a silver-containing composition in a solution, dried; the endoprosthesis made of polyvinylidene fluoride monofilaments of the diameter of 0.09-0.15 mm in the form of a form-stable combined weaved knitted cloth at surface density of the endoprosthesis 80-200 g/m2, processed for 2-4 hours in 3-15% silver nitrate solution in dimethylsulphoxide, dried in air for 17-20 hours, processed again, dried, additionally processed in the composition consisting of 4-8 wt % of aqueous sodium hydroxide, 6-10 wt % of aqueous ammonium and 0.3-0.7 wt % of aqueous glucose in proportions 100:4:4, at temperature 20-25°C, and then washed in water, and dried. According to the 2 version, the endoprosthesis made of polypropylene monofilaments of the diameter of 0.07-0.15 mm, at surface density 20-120 g/m2, processed in 5-15% silver nitrate solution in dimethylsulphoxide, dried for 5-8 hours, processed again, dried, processed in the composition (as provided by the first version) in proportions 100:7:9 at temperature 20-25°C, and then washed in water, and dried.
EFFECT: group of inventions provides prolonged antimicrobial action of the endoprosthesis.
2 cl, 2 tbl, 3 dwg
SUBSTANCE: invention refers to medicine, particularly traumatology and orthopedics, and can find application in treating false joints of long bones. What is described is a method for preparing a non-toxic porous implant of polylactic acid with controlled pore size for building of long bone defects involving melting the polylactic acid granules in a melting pot immersed in thermally stable oil with porogen presented by sodium chloride crystals 100-250 nm to be washed out by aqueous solutions of antiseptics. The implant is prepared with no toxic solvents added and has a pre-set pore diameter.
EFFECT: improved efficiency of the method.
SUBSTANCE: invention relates to a method of producing composite material from titanium nickelide-based alloys. The disclosed method involves process connection of a basic semi-finished product and porous components via self-propagating high-temperature synthesis, wherein titanium nickelide is additionally introduced into the structure of the composite material on selected areas of the semi-finished product. Titanium nickelide is a powder with the following grain-size distribution: 50-100 mcm - 60 wt %, 100-150 mcm - 40 wt %, and is introduced into said structure by sintering at 1260-1280°C for 1-5 minutes.
EFFECT: widening the pore size interval towards small values.
4 dwg, 1 ex
SUBSTANCE: invention relates to field of medicine. Described is method of biocompatible coating on implant surface which lies in precipitation on implant surface of polysilicon film in reactor. Obtained polysilicon film is subjected to chemical etching to form nanostructured superficial layer of porous polysilicon. Etching of polysilicon film nis carried out submerging implant into mixture which contains 50-55% water solution of tetrafluoroboric acid (HBF4), 70-90% water solution of nitric acid (HNO3) and anionic surface active substance on the basis of ammonium salt of perfluorsulfonic acid RfSO3NH4 in amount 5·10-3-10-2 (wt %), where Rf - C8F17 or C2F5OC3F6OC2F4, or C6F13CH2CH2. Used are water solution of acids with ratio of their volume parts: HBF4:HNC3, as (100-800):(1:1.1), with further washing of implant with deionised water and drying.
EFFECT: extension of technological possibilities of the method irrespective of materials used and constructive abilities of implants.
2 cl, 1 dwg, 2 ex
SUBSTANCE: group of inventions refers to medicine, and can be used for production of transplantable tissues. A method for cell-free organic tissue preparation for living cell reimplantation involves cell-free tissue preparation on a substantially flat surface and creation of a number of holes on the surface, spaced along the whole surface mentioned above and arranged so that they penetrate deep down at least a portion of thickness of said tissue with the holes designed for keeping the reimplanted living cells. Said number of the holes is created by means of one or more metal needles connected to a power supply which on each needle point induces current flow of such intensity and of such waveform to provide adequate energy for destruction of molecular couplings comprising organic tissue near to the needle point mentioned above. Each hole is formed by current flow and is great enough that the needle point mentioned above could penetrate into a space formed by opening of the molecular couplings. The group of inventions also refers to cell-free organic tissue for living cell reimplantation produced by said method.
EFFECT: group of inventions enables reducing time of producing transplantation tissue and provides living cell penetration along the whole thickness of cell-free tissue.
24 cl, 4 dwg
SUBSTANCE: invention refers to medicine and concerns composites for waxed reconstruction of the injured bone tissues. High-porous elastic chitosan-gelatin matrixes of porosity 90 % or more consist of chitosan and contain gelatin up to 60 wt % and sodium lauryl sulphate up to 0.2-0.4 wt %. The porous structure is produced by introducing the additives, freezing and sublimation drying.
EFFECT: due to elasticity and high porosity, said sponges fill bone defects with a minimum clearance that promotes the uniform formation of bone tissue throughout the defect; high solubility of matrixes provides fast bone tissue genesis.
1 tbl, 1 ex
SUBSTANCE: invention relates to field of medicine and deals with composite materials for plastic reconstruction of damaged bone tissues. Obtained is porous composite chitosan-gelatin sponge containing octacalcium phosphate in form of powder or granules. Introduction of gelatin increases sponge plasticity, which makes it possible to fill in bone defects of various form and size, as well as increases sponge solubility.
EFFECT: octacalcium phosphate contained in sponge demonstrates osteoinductive properties, which in combination with chitosan creates favourable conditions for formation of natural human bone tissue.
1 tbl, 9 ex
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention refers medicine, namely to preparing biological hydroxyapatite. What is described is a method for preparing biological hydroxyapatite involving pre-cleaning of bones, grinding, dissolving of bone tissue in hydrochloric acid, hydroxyapatite precipitation using a precipitant, filtration, heat treatment and deposit grinding; bones are ground to a particle size of 2.5-5 cm; bone tissue is dissolved hydrochloric acid of the concentration of 0.5-2M; that is followed by separating a liquid fraction of the suspension by filtration with the filtered solution added with chitosan of the concentration of 1.5-2 wt % at constant mixing until completely dissolved. The hydroxyapatite precipitant is 3-5M sodium hydroxide or potassium hydroxide added at constant mixing to ensure pH 7.0-7.5 of the reaction mixture; the filtered precipitation is heat treated by calcination at temperature 830°C for at least 40 minutes
EFFECT: fine hydroxyapatite powder of the particle size of 5 nm having the composition of microelements being as close as possible to that of human bone tissue.
SUBSTANCE: invention relates to medicine, namely to method of obtaining biocompatible bone-substituting material; powder of biological hydroxyapatite with particle size not more than 40 mcm is obtained from cattle bones, powder of hydroxyapatite is mixed with magnesium phosphate powder with particle size not more than 40 mcm with their ratio 1.0:0.25, water suspension of 2-amino-5-guanidine valeric acid is added to obtained mixture of powders with their further mixing for 40-50 minutes and drying at 50-60°C. Obtained mixture is combined with liquid, containing chitosane solution in 3% water solution of succinic acid and 2% water solution of sodium alginate with their ratio 0.3:0.7, ratio between liquid and powder mixture being 1.0:0.5. Before application hardening agent 5-10% water solution of calcium chloride is added to obtained plastic mass with ratio 1.0:0.3.
EFFECT: obtained material has through pores 0,7-100 mcm, general porosity 50-85%, is biocompatible, biodegradable and contains conditions, which eliminate necessity of t bone tissue transplantation and reoperation.
2 cl, 1 ex
SUBSTANCE: invention relates to composite materials based on calcium phosphate ceramic with improved strength properties and can be used in filling bone defects in traumatology and orthopaedics, maxillofacial surgery and dental surgery. To obtain reinforced porous composite materials based on hydroxyapatite and tricalcium phosphate, a porous ceramic matrix of a calcium phosphate ceramic with the ratio Ca/P ranging from 1.5 to 1.67 is saturated with 1-5% solution of average molecular or high molecular chitosan in 8% acetic acid at residual pressure of 0.1 to 0.3 Pa and holding for 10 to 30 minutes, followed by drying at room temperature for 24 hours.
EFFECT: invention increases strength of the composite material 8-9-fold.
3 ex, 1 tbl