Formation of osteoconductive biograft with bioorganic scaffold, human mesenchymal stromal cells, and platelet-rich plasma with its evaluation in vitro

Complex graft bioengineering is an actual topic in bone defects' repairing. For those, different scaffolds may be seeded with mesenchymal stromal cells and growth / differentiation factors. Natural role of platelet's factors in reparative processes justifies the possibility of its usage for mesenchymal stromal cells proliferation and differentiation into osteoblasts in vitro in terms of the scaffold-based bioengineering. To develop and evaluate in vitro biocompatibility and osteoconductivity of a complex biograft based on bioorganic scaffold seeded with human bone marrow mesenchymal stromal cells and saturated with growth and differentiation factors of allogeneic platelet rich plasma. The properties of viability and adhesion of human bone marrow mesenchymal stromal cells in four types of bioorganic scaffolds were evaluated with biochemical and immunomorphological methods. Scaffold with the least cytotoxicity was used as a basis for complex biograft formation, so as a carrier for cells and platelet-derived factors. Then, cells proliferation activity and osteogenic differentiation were estimated with biochemical, morphological, histochemical and molecular-biological methods. Study showed high viability of cells in all bioorganic scaffolds but least cytotoxicity had the one based on xenogeneic collagen sponge. We also found that allogeneic platelet rich plasma positively affects the proliferation and osteogenic differentiation of bone marrow mesenchymal stromal cells in a complex biograft in vitro. The properties of the developed complex biograft characterize its biocompatibility and osteoconductivity and make it potentially suitable for regenerative medicine, particularly for reconstructive surgery of bone defects.