Cell cultures in biocompatibility assessment of new materials for bone implants

The extended life expectancy and the increasing number of overweight people place bone diseases among the most serious health and social problems of our time. To meet this challenge there is a need for advanced new ma­terials for bone implants that maximally resemble the properties and behaviour of natural bones as well as ex­perimental designs to evaluate their biological activity. The aim of our study was to assess the cytocompatibili­ty of different classes of scaffolds for bone implants, including fine calcium phosphate powders, composite ma­terials, cements, and bacterial cellulose-based materials. Murine (bone marrow cells, cell cultures from bone ex­plants, BALB/c 3T3 and L929 fibroblasts) and human (Lep-3 and MRC-5 fibroblasts) cells were used as model sys­tems in our investigations. The effect of the materials on cell viability and proliferation was evaluated in direct (the cells were seeded on the material surface) and/or indirect (the cells were cultured in a medium where the ma­terials were incubated for various periods of time) experiments by the MTT test (the gold standard for cytotox­icity assessment), neutral red uptake cytotoxicity assay, double staining with acridine orange and propidium io­dide, SEM, Comet assay, Annexin V (FITC assay, alkaline phosphatase activity assay, alizarin red staining. The results obtained revealed that: the cell cultures used as model systems in our investigations have different advan­tages and disadvantages and provide complementary information on the biological activity of materials. Some of the examined scaffolds show promising biocompatibility and require additional studies on their osteoinductivi­ty and osteoconductivity