Physical and chemical properties and biocompatibility of nanostructured porous bone implants

The problem of bone repair is characterized by the growing relevance and high socio-economic importance. The known osteoplastic materials both naturally and artificial origin are not perfect. Therefore, the search for and development of new effective osteoplastic materials for reconstructive surgery is an urgent problem. The purpose of the study was to examine the physical and chemical properties, biocompatibility and osteogenic properties of developed collagen-hydroxyapatite biocomposite material having porous matrix, sufficient strength, biocompatibility and osteoconductive properties. The method for obtaining the material, methods for studying the properties of the material are mentioned in the paper. The structure of the material was demonstrated by ultrasonic microscopy and scanning electron microscopy, as well as by vapor adsorption isotherm of nitrogen. Also, methods for investigation the properties of strength of biocomposite samples, cell culture methods for evaluation of biocompatibility of the material, and cranial defect model in rats for evaluation of osteogenic properties were used in the study. Histology of bone defects filled with the material and without the material after 1, 4 and 8 weeks following defect forming were performed. The results obtained have shown porous structure of material (macropores of 100 - 200 mkm, large pores of 10 - 50 mkm, small pores in the range of 1 mkm and nano-pores of 50 - 200 nm). The composition of the mineral component of the material is close to the native bone in the ratio of collagen to hydroxyapatite amounts. The material is neutral on the pH and highly hydrophilic. Term of resorption of the material is close to the maturity of the bone formation. Studies have shown that the material is biocompatible, does not have an inflammatory and local irritating action. Osteogenesis in bone defects filled with material was significantly more active compared to control material-free defects.

The results indicate the prospects of the developed material for repair of fractured bone tissue.