Publications (19) View all
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Article: Materials from Titanium—Cobalt Alloys for Hybrid Implants
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ABSTRACT: We proposed a new method to increase the biocompatibility of porous materials that were synthesized from titanium and cobalt allows by the method of self-propagating high-temperature synthesis. This method suggested the introduction of calcium hydroxyapatite into the reaction mixture. Administration of calcium hydroxyapatite into the reaction mixture had a modifying effect on the structure and surface of the pore space and biocompatibility of composite materials. Administration of calcium hydroxyapatite crystals was followed by a significant decrease in the size of pores and appearance of water-soluble fractions, which inhibited the activity of cells. However, treatment with amorphous nanodispersed calcium hydroxyapatite increased the biocompatibility and adhesiveness of materials for mesenchymal stem cells. The pore space and mechanical characteristics of materials obtained with amorphous nanodispersed calcium hydroxyapatite were similar to the properties of natural bone. Moreover, these materials surpassed titanium—cobalt allows in biocompatibility. Our results indicate that the introduction of amorphous nanodispersed calcium hydroxyapatite into the reaction mixture during self-propagating high-temperature synthesis has a modifying effect on the pore space of composite materials and increases their biocompatibility and adhesiveness for cells. We conclude that these materials may be used as a carrier of stem cells and progenitor cells in hybrid implants.Bulletin of Experimental Biology and Medicine 04/2012; 147(1):160-165. · 0.27 Impact Factor -
Article: Evaluation of collagen gel microstructure by scanning electron microscopy.
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ABSTRACT: We performed qualitative comparison of freeze drying and chemical drying as methods of preparing 3D wet specimens for scanning electron microscopy. Human fibroblasts immobilized in collagen gel were used as a model system. Specimens fixed with glutaraldehyde were frozen in liquid nitrogen and freeze-dried at low temperature in high vacuum. In parallel experiments, glutaraldehyde-fixed samples were dehydrated in ascending ethanol solutions, absolute ethanol, and 100% hexamethyldisilazane and then dried at room temperature. Scanning electron microscopy microphotographs of collagen fibers and cells were characterized by high resolution and the absence of collapsed or deformed structures even at high magnification (×50,000) for both chemical drying and high-vacuum freeze drying. However, high-vacuum freeze drying is superior to chemical drying for the investigation of the internal space of 3D scaffolds, because sample fracture can be prepared directly in liquid nitrogen. These techniques are a part of the sample preparation process for scanning electron microscopy and can also be used for studies of cell adhesion, morphology, and arrangement in wet specimens (3D gels and flexible tissue engineering scaffolds).Bulletin of Experimental Biology and Medicine 07/2010; 150(1):153-6. · 0.27 Impact Factor -
Article: Bactericidal effects of non-thermal argon plasma in vitro, in biofilms and in the animal model of infected wounds.
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ABSTRACT: Non-thermal (low-temperature) physical plasma is under intensive study as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. The purpose of this study was to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma and to measure the effectiveness of plasma treatments against bacteria in biofilms and on wound surfaces. Overall, Gram-negative bacteria were more susceptible to plasma treatment than Gram-positive bacteria. For the Gram-negative bacteria Pseudomonas aeruginosa, Burkholderia cenocepacia and Escherichia coli, there were no survivors among the initial 10(5) c.f.u. after a 5 min plasma treatment. The susceptibility of Gram-positive bacteria was species- and strain-specific. Streptococcus pyogenes was the most resistant with 17 % survival of the initial 10(5) c.f.u. after a 5 min plasma treatment. Staphylococcus aureus had a strain-dependent resistance with 0 and 10 % survival from 10(5) c.f.u. of the Sa 78 and ATCC 6538 strains, respectively. Staphylococcus epidermidis and Enterococcus faecium had medium resistance. Non-ionized argon gas was not bactericidal. Biofilms partly protected bacteria, with the efficiency of protection dependent on biofilm thickness. Bacteria in deeper biofilm layers survived better after the plasma treatment. A rat model of a superficial slash wound infected with P. aeruginosa and the plasma-sensitive Staphylococcus aureus strain Sa 78 was used to assess the efficiency of argon plasma treatment. A 10 min treatment significantly reduced bacterial loads on the wound surface. A 5-day course of daily plasma treatments eliminated P. aeruginosa from the plasma-treated animals 2 days earlier than from the control ones. A statistically significant increase in the rate of wound closure was observed in plasma-treated animals after the third day of the course. Wound healing in plasma-treated animals slowed down after the course had been completed. Overall, the results show considerable potential for non-thermal argon plasma in eliminating pathogenic bacteria from biofilms and wound surfaces.Journal of Medical Microbiology 01/2011; 60(Pt 1):75-83. · 2.50 Impact Factor -
Article: Porous materials from titanium-cobalt alloys for hybrid implants.
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ABSTRACT: We proposed a new method to increase the biocompatibility of porous materials that were synthesized from titanium and cobalt allows by the method of self-propagating high-temperature synthesis. This method suggested the introduction of calcium hydroxyapatite into the reaction mixture. Administration of calcium hydroxyapatite into the reaction mixture had a modifying effect on the structure and surface of the pore space and biocompatibility of composite materials. Administration of calcium hydroxyapatite crystals was followed by a significant decrease in the size of pores and appearance of water-soluble fractions, which inhibited the activity of cells. However, treatment with amorphous nanodispersed calcium hydroxyapatite increased the biocompatibility and adhesiveness of materials for mesenchymal stem cells. The pore space and mechanical characteristics of materials obtained with amorphous nanodispersed calcium hydroxyapatite were similar to the properties of natural bone. Moreover, these materials surpassed titanium-cobalt allows in biocompatibility. Our results indicate that the introduction of amorphous nanodispersed calcium hydroxyapatite into the reaction mixture during self-propagating high-temperature synthesis has a modifying effect on the pore space of composite materials and increases their biocompatibility and adhesiveness for cells. We conclude that these materials may be used as a carrier of stem cells and progenitor cells in hybrid implants.Bulletin of Experimental Biology and Medicine 02/2009; 147(1):160-5. · 0.27 Impact Factor -
Article: Localization of green fluorescent protein in mouse preimplantation embryos.
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ABSTRACT: The localization of enhanced green fluorescent protein (EGFP) was studied in preimplantation embryos obtained from reciprocal mating of hemizygous C57Bl/6-Tgn (ACTbEGFP)1Osb/J mice with C57Bl/6 mice. Specific fluorescence of EGFP was observed in all oocytes and embryos obtained from transgenic females during all preimplantation stages and in embryos inheriting the EGFP gene from transgenic males starting from the 8 blastomere stage during the compactization period. EGFP mRNA or EGFP synthesized during oogenesis can be retained in embryos during the entire preimplantation period, while expression of EGFP gene transferred from the father coincides with the onset of compactization. The possibility of using these embryos in experimental mammalian embryology is discussed.Bulletin of Experimental Biology and Medicine 02/2008; 145(1):146-50. · 0.27 Impact Factor
