We compared the structure of lamellar bone in anterolateral zones of vertebral bodies in adult and senile subjects in health and osteoporosis. The appearance of structural signs of age-related osteopenia and enlargement of coplanar consolidations of the bone matrix crystals were noted. Osteopenia was more pronounced in osteoporosis, while the structural organization of the mineral component did not differ from that in age-matched controls.

Cultures of human and mammalian cells presenting 4 types of differentiation (normal human fibroblasts and myoblasts, human and Syrian hamster hepatoma cells, and mouse/mouse hybridoma cells) were used in a panel biotest system. This system allowed to evaluate the cytotoxic and stimulatory effect of bioactive compounds by determining the dose-effect relationships and some quantitative parameters including LD(50). Examination of some biolactive compounds of different nature (sangviritrin, escin, deltostim, cycloheximide, dexamethasone) confirmed high efficacy of this biotest system.

Three groups of biostable composite materials were studied. The initial binder polymers (polymethylmethacrylate, polyamide-12, superhigh-molecular-weight polyethylene) and hydroxyapatite-containing composites on the basis of these polymers were tested. Biostable polymers, including those containing hydroxyapatite, were nontoxic for fibroblasts and mesenchymal stem cells: the adhesion parameters for these cells were maximum for polyamide-12 and superhigh-molecular-weight polyethylene and did not depend on the presence of hydroxyapatite. Cell adhesion to "pure" polymethylmethacrylate was significantly lower than to other composites, but increased after integration of hydroxyapatite. The efficiency of proliferation of fibroblast and mesenchymal stem cell on the surface of polyamide-12 and superhigh-molecular-weight polyethylene was maximum and did not depend on the presence of hydroxyapatite. The efficiency of cell proliferation on the surface of "pure" polymethylmethacrylate was low, but increased significantly if it was combined with hydroxyapatite, particularly in areas of mineral particles accumulation. It seems that the presence of high amounts of hydroxyapatite in polymethylmethacrylate samples promotes cell adhesion and proliferation.