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Th e problem of scientifi c investigations in the selection of fi xators for osteosynthesis in treating ailments with fractures and deformities of the facial skeleton bones, which will require reconstructive surgery, is considered. Literature data on the use of various types of materials for osteosynthesis are given. It was established that the development of new biologically active composite materials for the production of bone plates for osteosynthesis, which would meet the basic requirements of bone surgery: biocompatibility, strength, fl exibility, ability to biodegrade, stimulation of tissue regeneration and prolonged therapeutic action, is an urgent direction of modern science and practical medicine. To solve this problem, the use of fi xation structures for osteosynthesis based on biodegraded epoxy polyurethane (EPU) composite material with bioactive action (EPU-HAP-LEV) is proposed. Biological activity is ensured by the presence of hydroxyapatite and levamisole fi llers in the EPU composite. Representative results of physical-mechanical, physicalchemical, and medical-biological studies, which preceded clinical trials of the composite material EPU–HAP–LEV in the form of osseous plates for osteosynthesis, are given. According to the obtained results, the EPU–HAP–LEV composite material is non-toxic, biocompatible and bioactive, capable of biodegradation and prolonged release of levamisole, has the necessary strength characteristics (fl exural strength - 27.1 MPa, tensile strength - 24 MPa, relative elongation at break 5.3 MPa), which made it possible to manufacture fi xators for osteosynthesis in the maxillofacial area and allowed to recommend them for clinical use. In the clinic, 76 patients with facial skull fractures were treated with polymer plates with screws, which are made of the EPU-HAP-LEV composition. An example of the clinical use of bone plates for osteosynthesis made of EPU-LEV-HAP is presented and their compliance with the medical purpose, eff ectiveness in the surgical treatment of maxillofacial fractures in areas that do not bear a signifi cant masticatory load, as well as in biomechanically stable fractures is established. [ABSTRACT FROM AUTHOR]

A series of polymeric composites based on polyurethanes with copolymer fragments of poly(vinyl butyral-vinyl acetate-vinyl alcohol) and 1,6-hexamethylenediamine filled with modified precipitated silica were synthesized. The content of silver in the nanocomposites was 0.1–0.2 and of copper – 0.14 and 0.2 mmol per 1 g of SiO2 (02AgCu; AgCu and 01Ag samples). The content of silver-containing silica filler in the polymer composites was 0.1, 0.5 and 1.0 wt. %. By means of the IR spectroscopy, it has been found that a physical immobilization of modified silica in the polymeric matrix takes place due to the presence of intermolecular hydrogen bonds. The influence of fillers on the structure and properties of polymer materials, in particular, on thermophysical properties and physico-mechanical parameters (tensile strength and relative elongation at rupture), were investigated. The results of physicomechanical tests indicate that the strength characteristics of polyurethane depend on the content and concentration of fillers. It has been found that the polymeric sample filled with 02AgCu nanocomposite (0.2 mmol of Ag and Cu per 1 g of SiO2) has the highest strength of the rupture. It has been shown that the introduction of modified silica leads to a reduction of relative elongation at rupture of polymeric nanocomposite. The highest values showed the sample filled with AgCu (0.1 and 0.12 mmol Ag and Cu, respectively, per 1 g of SiO2). The introduction of silver-containing silica nanocomposites into a polyurethane, containing polyvinylbutiral copolymer fragments, leads to an increase in tensile strength and reduction of relative elongation at rupture. Polymeric composite with 0.5 wt. % of filler had the highest values of physico-mechanical parameters. It has been shown that the thermosphysical characteristics depend on the concentration and composition of the fillers and have a nonlinear character. The synthesized nanocomposites can be effectively used as biomedical materials. [ABSTRACT FROM AUTHOR]

A number of polyurethane ureas (PUUs) containing 1,8-diamino-3,6-dioxooctane (DOODA) in their structure as a macrochain extender were synthesized with a different molar ratio of 4,4'-diaminodiphenylmethane (DADPh) to DOODA as 30:70; 50:50; 70:30. Synthesized polymers are elastic, transparent films with a thickness of 0.3 mm. According to the results of physical and mechanical tests, the tensile strength of the synthesized PUUs is in the range of (0.7-2.0) MPa, and the relative elongation at break is in the range of (73.9-584.7)%. The best physical and mechanical characteristics have the polymer synthesized with a ratio of DADPh:DOODA as 0.3:0.7 with a tensile strength of 2.0 MPa and a relative elongation of 522%. The formation of PUUs was confirmed by the method of IR-spectroscopy. Thermophysical properties synthesized by DSC, TGA methods were studied. It was established that the glass transition temperature (Tg) in a number of synthesized PUUs with DOODA is in the range from (minus) 18.50 °C to (minus) 34.52 °C. An increase in the content of 1,8-Diamino-3,6-dioxaoctane in the PUUs structure leads to a decrease in Tg and a slight increase in ΔCp during the second heating. According to the TGA, the heat resistance characteristics of the synthesized PUUs depend on the content of DOODA. When entering the structure of the PUUs DOODA, a decrease of the temperature of the start of the decomposition (T0) and the temperature of the maximal speed of the decomposition (Tmax), which is non-linear nature. T0 of the synthesized PUUs is in the range (275.16-289.8)°C and is accompanied by a slight loss of mass (0.007-0.093)%. Synthesized PUUs are heat-resistant to a temperature of 275.16 °C, which makes it possible to carry out dry sterilization of samples without changing their characteristics. Synthesized PUUs are promising materials for the immobilization of medicinal substances for further use in medicine. [ABSTRACT FROM AUTHOR]

Developed a new composite material with Dacarbazine based on polyurethane foam (PPUS) The content of the drug substance Dacarbazine (DAC) in the composition was 0.5 wt. % and 1.0 wt.%. PPUS was obtained on the basis of a mixture of oligourethane diisocyanates (OUDIC) synthesized on the basis of 2,4-;2,6-toluene diisocyanate and polyoxypropylene glycols (POPG) MM 1002 and MM 2002 in a ratio of 1:1. Comparative physical and mechanical tests were performed. According to the obtained results, PPUS with DAC in the amount of 1 wt.% have physical and mechanical parameters (σ = 7.8, MPa, ε = 100% and σadhesion = 4.5 MPa), that will meet the requirements for replacement implants for ophthalmology. According to the results of IR spectroscopy, the possibility of chemical immobilization of Dacarbazine on the selected polymeric carrier was established. The thermophysical properties of the synthesized PPUS with Dacarbazine by DSC and TGA methods were studied. It was found that the glass transition temperature (Tg) is practically independent of the content of DAC. Tg PPUS with 0.5 wt.% DAC - (minus) 49.70 °C, Tg PPUS with 1.0 wt.% DAC - (minus) 50.09 °C. According to TGA, the obtained materials are characterized by the same heat resistance characteristics and practically do not depend on the content of DAC. The onset temperature of thermal decomposition (To) is in the range (290,96-298,61) °C and is accompanied by a slight weight loss (0.02-0.04 %). The temperature of maximum decomposition rate (Tmax) is in the range (331.93-333.95) °C. According to the results of the dynamics of Dacarbazine release study from PPUS samples with a DAC content in the composition of 0.5 and 1.0 wt. % found that the composition of PPUS with a content of DAC 1 wt. % have a higher percentage of medicine, which on day 14 is ~ 64 %. The developed PPUS with Dacarbazine are promising materials for use as implants for ophthalmological surgery. [ABSTRACT FROM AUTHOR]

The basis of the technology for obtaining polymers for medical purposes is the synthesis of the polymeric base and the introduction into it of various active substances, taking into account properties of the components. The article is devoted to the synthesis and research of biologically active polyurethane foams. New polyurethane foams have been created with a cycloserine, which in the future can be used as polymeric materials for the treatment of wounds and burns. The obtained polymeric materials were investigated by physicochemical and biological methods. Also, the new polymer materials obtained were investigated by electron micrography. Studies using IR spectroscopy have shown that cycloserine is immobilized on a polymer matrix by physical bonds. When the cycloserine is introduced into the polymer matrix, the adhesive properties are improved and the structure of the polymeric composite material becomes more porous. The obtained results testify to the prospect of using the created polymeric materials in medical practice. [ABSTRACT FROM AUTHOR]

Synthetic polymers are increasingly used in medical practice. Modification of polymers with biologically active substances, which can stimulate regenerative processes, is an urgent task. Conjugation of folic acid to ferrocene is resulted in a new compound, which may combine biological activity of folic acid and immune-boosting properties of ferrocene. The purpose of the study was to obtain polyurethane ureas with folate-derivative of ferrocene for medicine, research and assessment of their biocompatibility and biological activity. Toxicological, biochemical and histological studies were undertaken. It has been shown that folate-derivative of ferrocene entered to the tissue culture activates cellular elements of fibroblastic and macrophage rows. Folate-derivative of ferrocene entered to polymer material during implantation into the body of experimental animals stimulated monocytemacrophage elements at the early stages and formation occurred of the fibrous capsule around the implant. Cellular reactions around the implanted polymeric samples were typical for aseptic inflammation and did not lead to the development of acute and chronic inflammation. Consequently, obtained polymeric materials with folate-derivative of ferrocene may be recommend for clinical trials. [ABSTRACT FROM AUTHOR]

Up-to-date literary data concerning of biologically active composites on basis of polyurethane and epoxides of useing at medicinal practice for bone defects reconstructing. It is shown that for today one of perspective materials for useing in surgical stomatology and maxillofacial surgery for production the under-bone plates for an osteosynthesis are biologically active epoxy polyurethane composites. Development of the direction of creation of new constructional materials for an osteosynthesis on the basis of biocompatible and biologically active epoxy polyurethanes is presented. [ABSTRACT FROM AUTHOR]

The article is devoted to the development and research of the structure and properties of polyurethane foam (PUF) composite materials with the antibacterial enzyme lysozyme. A series of PUF composite materials with lysozyme of various concentrations (1, 3 and 5 wt %) were obtained. It is established that the immobilization of lysozyme occurs due to intermolecular hydrogen bonds by the method of IR spectroscopy. According to the results of physical-mechanical tests the adhesive strength of polyurethane foam compositions with lysozyme is in the range of 0,82–1,16 MPa. Th e introduction of lysozyme into the composition of polyurethane foams and an increase its amount causes a decrease in the values of adhesion strength by 18,1– 29,3 %. According to differential scanning calorimetry the tested systems are single-phase with a glass transition temperature in the range of -49,20 to -49,86°C. The introduction of lysozyme into the composition causes an increase heating capacity at the glass transition, which can be associated with a decrease of the packing density of macrochains resulting in an increase in free volume, which leads to an increase molecular mobility. According to the results of the analysis of transmission optical microscopy micrographs the studied PUF have a microporous structure, which depends on the content of filler in their composition. It was found that the presence of lysozyme in the composition of composite materials leads to a decrease in the percentage of porosity, an increase in the number of pores with a diameter of up to 300 μm, which is 76,7–82,4 % (while for PUF – 69,5 %) and the absence of pores with a diameter larger than 990 μm. Thermogravimetric characteristics indicate the heat resistance of the synthesized PUF to a temperature of 179,95°C, which allows dry sterilization of samples without changing their characteristics. PUF composite materials with lysozyme are promising materials that can be used in medical practice as polymer compositions for the treatment of wounds and burns. [ABSTRACT FROM AUTHOR]

PUU was obtained on the basis of DPP, GMDA and PVB copolymer for different ratios of DA to PVB as 30:70; 50:50; 70:30 and a number of composite materials with lysozyme were obtained (enzyme content 1 wt.%). The data of IR-spectroscopy studies confirm that the immobilization of lysozyme occurs due to intermolecular hydrogen bonds (physical immobilization). It is established that with increasing amount of PVB copolymer in the structure of polymeric materials, there is an increase in tensile strength and elongation at break. The tensile strength of a series of PUU with increasing PVB are in the range of 1.74-2.29 MPa, and the indices of the elongation at break are in the range of 97-204 %. According to the results of physical-mechanical studies, the introduction of the enzyme into the PUU leads to an improvement of their properties. For compositions with Lysozyme, the tensile strength is 1.43-2.84MPa and the elongation at break is 104-212 %. The intrinsic viscosity of the polymers is in the range 0.46-0.97 dl/g. For PUU, synthesized at a percentage of GMDA:PVB of 70:30 and 30:70, the introduction of lysozyme leads to a slight decrease in the glass transition temperature compared to samples without lysozyme, for PUU synthesized at a percentage of GMDA:PVB of 50:50, leads to increase the glass transition temperature. It was established that the systems under study are single-phase. [ABSTRACT FROM AUTHOR]

The influence of the BM 199 model environment on the structure and properties of composite materials with Doxorubicin based on polyurethanes (PU) with isocyanurate branching nodes, in which the content of 2,4,6-triisocyanate(trishex amethylene)isocyanurate (HDT-90) was 0.25.0, 5, 0.75 mol, and the content of the drug Doxorubicin is 0.5% wt. It was found that the obtained materials exhibit the ability to biodegradation in vitro. In a study by IR spectroscopy of changes in the structure of polyurethane composites with Doxorubicin under the influence of BM 199, it was found that, in the series of polyurethanes, with an increase in the residence time in the model environment, a decrease in the number of weakly bound (νNH 3516 cm-1) and strongly bound bonds of NH groups (νNH 3515 cm-1), which can occur both due to the biodegradation of the polymer base, and as a result of the release of Doxorubicin. For all the samples under study, during their stay in the biological medium, there is a decrease in the strength at break by 1.5-1.9 times and an increase in the relative elongation by 1.1-1.4 times. According to the data of physical-mechanical tests for all studied materials, the process of biodegradation in vitro is accompanied by an increase in elasticity during the entire study period. According to the results of the study of the dynamics release of Doxorubicin, it was found that from polyurethane composites with isocyanurate branching nodes containing 0.75 mol of HDT-90 in the structure, Doxorubicin is released within 21 days in an amount of 17.6%, which is 4 times more than for samples compositions with 0.5 mole of HDT-90, from which 4.4% of Doxorubicin is released, which may be related to the packing density of the macrochain of the polymer base. Composite materials based on polyurethanes with izocyanurate fragments and Doxorubicin can be proponated for medical and biological tests as material for stem implantation of tissue with prolong medicinal action. [ABSTRACT FROM AUTHOR]

Synthesized polyurethane with isocyanurate fragments (PU) based on polyoxypropylene glycol (POPG 1000), TDI (2,4; 2,6: toluene diisocyanate) and 2,4,6-triisocyanate (trishexamethylene) socyanurate (ICC, Tolonate ™ HDT-LV, MM 1200) with a ratio of NCO: OH = 1: 1 in N,N'-dimethylacetamide (DMAA). The tensile strength (σ) of the synthesized PU was 2.6 ± 0.2 MPa; elongation at break (ε) - 58.0 ± 5.5%. The immobilization of Ifosfamide (IFO) on isocyanurate-containing polyurethane was carried out by introducing a solution of IFO in DMAA into the reaction mixture at the rate of 1 mg of IFO per 1 cm2 of PU fi lm. The synthesized polymer (PU+IFO) is characterized by σ = (3.4 ± 0.3) MPa; ε = (53.0 ± 6.6)%. It was found that the modification of PU synthesized at a molar ratio of POPG: ICC = 3: 2, Iphosphamide does not lead to significant changes in physical and mechanical properties. According to IR spectroscopy, an IFO is immobilized on a polymer matrix due to intermolecular hydrogen interactions. The biodegradability of isocyanurate-containing polyurethane compositions with IFO was studied by changing the structure and properties under the influence of biological medium 199 (BM 199) for 1 and 6 months. It was found that during incubation in BM 199, samples of PU and PU+IFO are not subject to signifi cant structural changes. The biodegradation of PU+IFO samples aft er 6 months of incubation is accompanied by a slight increase in the microsegregation of fl exible (polyester) and rigid (urethane, isocyanurate) blocks, which leads to an increase in the mobility of the fl exible block, respectively, to an increase in the number of hydrogen bonds and, as a result, to an increase in the glass transition temperature. A study of tissue cytotoxicity of isocyanurate-containing polyurethanes with Iphosphamide by tissue culture allows us to conclude that there is no histotoxic eff ect of IFO in the composition of PU on the growth and development of tissue culture. According to the express toxicology assessment method, composite materials with ifosfamide are biocompatible. [ABSTRACT FROM AUTHOR]

The influence of the model biological environment 199 (BS 199) on the structure and properties of composite materials with lysozyme on the basis of polyurethane-urea (PUU) with fragments copolymer poly-vinyl butyral, vinyl acetate with vinyl alcohol (PVB) has been studied. Infrared spectroscopic and physical-mechanical investigations of polyurethane urea with lysozyme have been performed, which predict the structure of fragments of PVB copolymer after incubation in a biological medium 199. It was established that under the influence of BS 199 biodegradation of the studied PUU and compositions with lysozyme on their basis is accompanied by the structuring of the polymer matrix by destroying and redistributing the network of intermolecular hydrogen bonds to form a more perfect physical interactions grid. The method of spectrophotometry has established that the developed composite materials are capable of prolonged release of an antibacterial preparation of lysozyme, that for the PUU, synthesized for the ratio of GMDA:PVB as 70:30 for 4 days is 75.0 %. [ABSTRACT FROM AUTHOR]