Method for preparing non-toxic porous implant of polylactic acid for building of long bone defects
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.
The invention relates to medicine and can be used, in particular, in trauma and orthopaedic practice for full reparation of defects bones when diastasis up to 2-2,5 cm, in particular during the formation of the defect after resection of false joints of long bones. Upon the occurrence of traumatic defects or other situations associated with the planned resection of the pathological part of this bone, one of the promising methods is the replacement of bone defect biodegradiruemym implant.
Of the proposed methods recently drew the attention of the manufacturer of the implant from polylactic acid. The advantage of this material is reactively living tissues, hypoallergenic, long enough degradation, absence of toxic products during enzymatic depolymerization in tissues (lactic acid enters the Krebs cycle).
It must be porous (pore Diameter of 100-200 nm (Cima, L.G., Vacanti, J.P., Vacanti, C., et al. Tissue engineering by cell transplantation using degradable polymer substrates. J. Biomech. Eng. Str, 143, 1991), the pores must be connected, which promotes germination of granulation tissue, migration of fibroblasts by transforming them into osteoblasts on the walls of the pores of the matrix and subsequent biodegradation.
Following the venture is the event of obtaining a porous material of polylactic acid:
- Leaching of the particles of the evaporated or lyophilized polymer solution (A.G. Mikos, and other Preparation and characterization of polylactic acid foams. Polymer, No. 35, page 1035, 1994), in which dissolve the polymer in an appropriate organic solvent (xylene, chloroform, methylene chloride), then added to a solution of the corresponding particles of porogen, insoluble in this solvent (soluble salts and others), then remove the organic solvent and remove particles of porogen by dissolving in a polar solvent (water and others). The advantage of this method is that when using 70% of porogen by weight relative to the weight of the polymer formed pores are highly interconnected. The use of toxic organic solvents with a probability of incomplete removal of their porous structure material is a disadvantage of this method.
The foaming gas under high or ultra high pressure (Novel approach to fabricate porous sponges of poly(-lactic-co-glycolic acid) without the use of organic solvents. David J. Mooney, Daniel F. Baldwin, Nam P. Suh, Joseph P. Vacanti and Robert Langer. Biomaterials Volume 17, Issue 14, July 1996, Pages 1417-1422), requires a long time and/or equipment to create a high-pressure neutral gas.
- Phase separation, spinodal decomposition or emulsification followed by lyophilization, uses toxic organic high-molecular solvents (naphtha is in, phenol, 1,4-dioxane) or, using the techniques of emulsification and subsequent cryolipolysis obtained pore size usually does not exceed 10-30 nm, which negatively affects the dynamics of biodegradation of the polymer matrix in vivo and does not promote migration of cells into the pores of the matrix.
- Casting and after making porogen in the melt, where as porogen use gelatin - biologically reinerton substance complex protein structure (Cima, L.G., Vacanti, J.P., Vacanti, C., et al. Tissue engineering by cell transplantation using degradable polymer substrates. J. Biomech. Eng. Str, 143, 1991. Thomson, Robert C.1; Yaszemski, Michael J.2; Powers, John M.3; Mikos, Antonios G. Journal of Biomaterials Science, Polymer Edition, Volume 7, Number 1, 1996, p.23-38)having antigenic activity.
The objective of the invention is to develop methods of obtaining porous implant of polylactic acid without the use of toxic solvents with a given diameter of pores connected.
The problem is solved in that in the method of obtaining non-toxic porous implant made of polylactic acid for replacement of defects of the long bones, including the melting of the granules polylactic acid in a metal crucible with the addition of porogen, as porogen use crystals of salt the size of 100-250 nm, followed by washing in distilled water with the addition of antiseptics, while the ü immersed in a heated heat-resistant mineral oil.
The method is as follows.
Take a sample of pellets of polylactic acid in the amount of 30 grams of salt crystals in the amount of 15 grams, the size of the crystals of 100-250 nm, placed in a stainless steel crucible. The crucible is heated to a temperature transition of the polymer to a viscous state (185-190°C). Heat transfer to the crucible from the heating element of an electric furnace with thermostat is performed by immersion of the crucible in a heat-resistant mineral oil. Temperature control is immersed in mineral oil sensor of the electronic thermometer. Upon reaching the desired temperature (~190°C) and viscosity of the contents of the crucible mechanically stirred until a homogeneous state. The resulting mass is put in a cylindrical or other configuration of the metal mold and cool it. Then, after cooling, salt remove from the finished implant by means of washing with aqueous solutions of antiseptics.
The proposed method for obtaining highly porous implant of polylactic acid allows to obtain non-toxic implant, easy to use, does not require complicated hardware design.
The method allows evenly without combustion to melt granules of the polymer and to obtain a porous material with controlled pore size, dependent on the particle size of porogen, with a predictable degree of interconnectivity of the pores, not zag is ananny organic solvents.
The method of obtaining non-toxic porous implant made of polylactic acid for replacement of bone defects in long bones, including the melting of the granules polylactic acid in a metal crucible, immersed in a heat-resistant mineral oil, with the addition of porogen, characterized in that as porogen use crystals of salt the size of 100-250 nm, followed by washing them with aqueous solutions of antiseptics.
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
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: invention concerns medicine, namely to reconstructive surgery, traumatology-orthopedy, maxillofacial surgery, stomatology and can be applied at osteo-plastic operations. For delivery of medical products immediately in a zone of defect and their prolonged influence in the centre of a lesion medicinal preparations are dissolved in a normal saline solution in a dose providing local effect, collagen-containing component is added to a solution in the ratio 9-20 g: 100 ml of a solution also admix with the carrier from dispersed allotransplants in the ratio of 1:1-3.
EFFECT: method allows lowering a dose necessary for reception of medical effect in 10 times, and also allows accelerating reparative processes in a defect zone.
SUBSTANCE: invention concerns medicine, particularly composition for bioactive microporous material, including medical glass reduced to powder, hydroxyapatite powder and carbonate porophore, with addition of zeolite for micropore structure generation and enhancement of durability of ceramic glass materials and articles.
EFFECT: efficient method of obtaining bioactive ceramic glass materials based on claimed composition and applicable in prosthetics of osseous tissues, teeth or their fragments of complex form or mixed porosity structure.
12 cl, 6 ex, 1 tbl
SUBSTANCE: described is material for closing osteal defects at reparative-plastic operations, manufacturing osteal implants, replacement of defects at various osteal pathologies. The material is made of calcium phosphate, represents particles of carbon-replaced hydroxyapatite with the general formula: Ca10(PO4)x(OH)y(CO3)z where 5<X<6, 0<Y<2, 0<Z<1, contains of 0.6 to 6.0 wt % CO3 2- groups, with an adjustable nuclear ratio of calcium/phosphorus of 1.5 to 2.1. The material is made in the form of porous spherical granules with diameter of 100 to 1000 microns, having a rough microrelief of an external surface, with the size of pores from 0.5 to 15.0 mcm at the general open porosity of 50 to 80% and a specific surface of 0.3 to 0.6 m2/g. The material possesses the following properties: high adhesion in relation to cells; combination of osteoconductivity properties and osteoinductance; affinity of chemical and phase structure of implanted material to structure of replaced tissue; adjustability of rate of dissolution at its replacement by an osteal tissue; possibility of three-dimensional uniform filling of the osteal defect repeating its form. The material can be saturated with autologous mesenchymal stem cells.
EFFECT: improved properties of the material.
2 cl, 1 tbl, 6 dwg
SUBSTANCE: described method of implant material production on basis of pored polytetrafluorethylene includes processing of base surface which serves as a substrate, deposition of surface layer modified with alloying elements onto processed substrate by magnetron deposition of one of targets selected from the following metals: titanium, zirconium, hafnium, niobium, tantalum, mainly titanium, carbides of mentioned metals, mainly titanium carbide of TiC0.5; compound ceramic materials from the following group: TiC0.5+10 mass.% CaO; TiC0.5+10 mass.% CaO+2 mass.% KMnO4; TiC0.5+10 mass.% ZrO2; TiC0.5+10 mass.% hydroxyapatite (Ca10(PO4)6(OH)2, deposition of one of mention targets at that is carried out at pressure 1-2x10-1 Pa, at substrate temperature between 150-170°C, in argon or argon and nitrogen medium at nitrogen partial pressure 14%. Implant material includes base of polytetrafluorethylene of porosity 3.0-40.0%, and surface layer of thickness not less than 50 nm modified with alloying elements composing mentioned targets. Surface layer at deposition of metal target in argon medium contains mentioned metal as alloying element mainly titanium. Surface layer at deposition of metal carbide in argon and nitrogen medium contains Ti-C-N as alloying elements. Surface layer at deposition of ceramic target TiC0.5+10 mass.% CaO in argon and nitrogen medium contains Ti-Ca-C-O-N as alloying elements. Surface layer at deposition of ceramic target TiC0.5+10 mass.% CaO+2 mass.% KMpO4 in argon and nitrogen medium contains Ti-Ca-Mn-K-C-0-N as alloying elements. Surface layer at deposition of ceramic target TiC0.5+10 mass.% ZrO2 in argon and nitrogen medium contains Ti-Zr-C-O-N as alloying elements. Surface layer at deposition of ceramic target TiC0.5+10 mass.% (Ca10(PO4)6(OH)2, in argon and nitrogen medium contains Ti-Ca-P-C-O-N as alloying elements.
EFFECT: method of implant materials production as a substrate for hybrid implants characterized by improved physicochemical, biomechanical properties and enhanced biological activity to biotissues.
10 cl, 1 dwg
SUBSTANCE: invention refers to medicine. There are described medical implanted devices made of a polymer material and a separation agent wherein the device is a cast reservoir implant, while the separation agent has a molecular weight (M.w.) of min. 1000. The separation agent can be presented by a non-ionic surfactant, such as Bridge-35, polyoxyethylene (20) sorbitan trioleate, Tween 20, Tween 80, vitamin E TPGS, and a mixture of any two or more of them. The hydrated implants can have a surface area of approximately 500 mm2 or more.
EFFECT: used separation agents causes no undesired reactions with cartridge polymer and are safely introducible in a patient.
29 cl, 5 tbl, 3 ex
SUBSTANCE: invention refers to medicine. High antimicrobial activity and desired smoothness providing high thromboresistance are ensured by modifying a product surface, e.g. a polyurethane polyurethane with chlorhexidine and/or its salts with the modification procedure ensured by applying 0.5-4% polyurethane of molecular weight 10000 to 40000 units. in tetrahydrofurane containing chlorhexidine and/or its salts in the amount 0.25-5% (wt) in relation to polyurethane weight that is followed by tetrahydrofurane evaporation.
EFFECT: what is described is a polyurethane catheter with antimicrobial coating, the method for preparing the antimicrobial coating on polyurethane products and the method for producing the polyurethane catheters with the antimicrobial coating.
3 cl, 1 tbl
SUBSTANCE: invention concerns medicine, particularly neurosurgery. What is disclosed is a biocompatible, biostatic, non-toxic, translucent, however imaginable, elastic, strong, reliably fastened duraplasty graft made of a spatially cross-linked polymer prepared by photopolymerisation of methacrylic oligomers. A graft represents an elastic translucent double-layer film with one layers being relieved, while the other one is smooth. The relief is blue-coloured. Such colour provides intraoperative imaging of the graft for a surgeon. At the same time, the unit dimensions of the relief drawing are such that the graft is translucent enough to control the hemostasis efficiency. The layer adjoining the brain is smooth. A roughness degree of the smooth layer ranges within 10 to 20 nanometers to eliminate the adjoining tissue ingrowth into the graft and its opacity on service.
EFFECT: improved graft performance.
7 cl, 3 dwg, 3 ex
SUBSTANCE: invention relates to field of medicine, in particular, to ophthalmology. For intraocular lens applied are soft, with high coefficient of reflection acrylic materials, which contain arylacrylic monomer as single main element-forming monomer, as well as macromer additive for reduction of adhesiveness.
EFFECT: invention ensures application of claimed materials in intraocular lens, as well as other ophthalmological or otolaryngological elements, such as contact lens, keratoprostheses, corneal rings, implants, otolaryngological ventilation tubes and nasal implants.
19 cl, 4 tbl, 10 ex
SUBSTANCE: invention relates to medicine, specifically to surgical material and means for replacement of bone tissue defects. Surgical material contains biodegradable and biocompatible copolymer of 3-hydroxybutyrate and 3-hydroxyvaleriate (3-PHB/3-PHV) and calcium phosphate substances, with the following component ratio, in wt %: copolymer 65-90 and calcium phosphate substances 10-35. According to second version, surgical material, contains biodegradable and biocompatible copolymer, calcium phosphate substances and antibiotic, selected from group which consists of tienam, gentamicin, sulperazon and rubomycinum, with the following component ratio, wt %: copolymer 65-89; calcium phosphate substances 10-35; antibiotic 1-5.
EFFECT: obtaining biodegradable and high-strength surgical material for reconstruction of bone tissue defects of various etiology, which has high osteoinductive and antimicrobial properties.
21 cl, 5 dwg, 3 tbl
FIELD: medicine, pharmaceutics.
SUBSTANCE: invention relates to application in biomedicine, cell technologies, substituting and restorative surgery, in particular for manufacturing matrix-carrier, implanted together with cells into human organism in order to restore functioning of affected organ. Method lies in preparation of solution of polyoxybutirate-polyoxyvalerate (POB/POV) in dichloroethane, after which into solution introduced is icy acetic acid with the following component ratio, g: POB/POV - 1-2, dichloroethane- 10-12, icy acetic acid - 10-15; obtained solution is frozen in form at temperature minus (25-30)°C and sublimation drying of obtained semi-product of matrix is performed in vacuum chamber. Freezing of solution and sublimation drying of obtained semi-product of matrix are performed on padding, made from polytetrafluorethylene fiber and plate from water ice. Thickness of water ice plate is selected on condition of its complete sublimation during drying in vacuum chamber, sublimation drying of matrix semi-product on padding being performed on mesh from plastic threads. Initial pressure in vacuum chamber must be not lower than 100 Torr, and after dichloroethane evaporation from matrix semi-product pressure in vacuum chamber is reduced to ~0.01 Torr. Polymer matrix with bimodal structure of simply connected pores is produced.
EFFECT: simplification and cheapening of technology due to refuse from low temperature of performing vacuum sublimation drying.
7 cl, 4 dwg
SUBSTANCE: invention refers to medicine, specifically to hernia surgery. A synthetic prosthesis made of monofilament fibres with a coat containing 2% chitosan of molecular weight 80000 Da, polyvinyl alcohol, a cephalosporin antibiotic or two compatible or synergistic antibiotics mixed, glycerin in a certain proportions is fixed on an aponeurosis.
EFFECT: use of the invention provides effective antibacterial agents delivery into a plasty zone and prolonged intake into the tissues, applicability of monofilament meshes as explants, reduced pyoinflammatory wound complications and recurrent hernias.
SUBSTANCE: invention relates to a photocurable composition for a three-dimensional article containing the following in wt %: (a) a cation-curable component containing an oxetane compound 35-80; (b) a free-radical active component containing poly(meth)acrylate, which is not dipentaerythritol hexaacrylate 15-60; (c) an antimony-free cationic photoinitiator 0.1-10; (d) a free-radical photoinitiator 0.01-10; (e) one or more additives which increase impact resistance 0.01-40. The photocurable composition can be cured under the effect of actinic radiation and optionally heating, which enables to obtain three-dimensional articles which can be used in various aerospace fields and in methods of casting with consumable patterns. Described also is a method of producing a non-toxic photocurable composition by mixing all components and a method of making a three-dimensional article which is free from antimony.
EFFECT: obtaining solid components having sufficient strength, stable resin viscosity, improved impact resistance and elasticity of components.
25 cl, 45 tbl, 85 ex
SUBSTANCE: connecting element (10) is described, in particular a suture material for surgical application, which contains the first material (12) which is substantially rigid when its opposite sides are affected with respectively short-term tensile load, and the second material (11) connected with first material. The second material is substantially rigid when its opposite sides are affected with tensile load, and is made with the ability for slow shortening during the second period of time, longer than the first period of time.
EFFECT: connecting element shrinks over long periods of time and is rigid at short-term fast-increasing loads.
23 cl, 22 dwg
SUBSTANCE: there is described composition, which includes thermoplastic polymer, speed modifying agent and biologically active agent, which is suitable as implant for medication delivery with slow release into human or animal organism and which can be introduced in organism in liquid form.
EFFECT: characteristics of release and biodegradation of polymeric system with slow release are considerably improved.
2 tbl, 2 ex, 9 cl
SUBSTANCE: invention refers to medicine, namely orthopaedic dentistry, and may be used in making intraosseous implants by coating their metal substrate with plasma layers to be exposed to ion-beam modification. The presented method for making the intraosseous implant involves sandblasting of the implant surface by aluminium oxide particles, layered by plasma deposition on the implant substrates of the system of biocompatible coatings of various dispersion and thickness consisting of five layers: first two ones of titanium or titanium hydride, the next two layers of mixed titanium or titanium hydride and calcium hydroxyapatite differing by the contents of the components in the layers, and the fifth layer of calcium hydroxyapatite; then the multilayer system of biocompatible coatings is radiated in the vacuum medium of hydrocarbon gas by high-energy ions of inert gas with energy 40-130 keV and a radiation dose of 2000-5000mcKl/cm2.
EFFECT: method provides higher bioactivity and mechanical strength of the implant.
2 tbl, 2 dwg