Background Cerium-containing materials have wide applications in the biomedical field, because of the mimetic catalytic activities of cerium. The study aims to deeply estimate the biocompatibility of different scaffolds based on Ce-doped nanobioactive glass, collagen, and chitosan using the first passage of rabbit bone marrow mesenchymal stem cells (BM-MSCs) directed to osteogenic lineage by direct and indirect approach. One percentage of glass filler was used (30 wt. %) in the scaffold, while the percentage of CeO2 in the glass was ranged from 0 to 10 mol. %. Cytotoxicity was evaluated by monitoring of cell morphological changes and reduction in cell proliferation activity of BMMSCs maintained under osteogenic condition using proliferation assays, MTT assay for the direct contact of cells/scaffolds twice in a week, trypan blue and hemocytometer cell counting for indirect contact of cells/scaffolds extracts at day 7. Cell behaviors growth, morphology characteristics were monitored daily under a microscope and cell counting were conducted after 1 week of the incubation of the cells with the extracts of the four composite scaffolds in the osteogenic medium at the end of the week. Results Showed that at 24 h after direct contact with composite scaffold, all scaffolds showed proliferation of cells > 50% and increased in cell density on day 7. The scaffold of the highest percentage of CeO2 in bioactive glass nanoparticles (sample CL/CH/C10) showed the lowest inhibition of cell proliferation (< 25%) at day 7. Moreover, the indirect cell viability test showed that all extracts from the four composite scaffolds did not demonstrate a toxic effect on the cells (inhibition value < 25%). Conclusion The addition of CeO2 to the glass composition improved the biocompatibility of the composite scaffold for the proliferation of rabbit bone marrow mesenchymal stem cells directed to osteogenic lineage.

This research aims to evaluate cerium-doped nanobioactive glass/collagen/chitosan composites scaffolds with osteoblast mineralization of normal rabbit bone marrow mesenchymal stem cells (rBM-MSCs) and cancer osteosarcoma cells. The non-cellular in vitro bioactivity test was performed in simulated body fluids for periods 1, 3, 10, 20 and 30 d by measuring the calcium and phosphate ion concentrations by SEM/EDX analysis. While, the bioactivity of expanded and differentiated osteoblast cells derived from isolated rBM-MSCs by flowcytometric analysis was studied by histochemical staining with Alizarin Red and von Kossa to confirm the osteogenic differentiation process. Also, cell viability assay by MTT was used to measure the number of viable osteoblast cells cultured with scaffolds extracts. Also, the antitumor activity of the scaffolds was studied against cancer osteosarcoma cell lines using Sulforhodamine B (SRB) assay. The results showed that addition of cerium-doped nanobioactive glass to the composite scaffolds was triggered an increase in cell growth, proliferation and mineralization markers of osteoblast cells that increased with time as the highest concentrations of CeO 2 in nanobioactive glass (sample CL/CH/C10). Cell viability proved also that all scaffolds and their extracts showed proliferation inhibition with time < 25% reference to final cell number of control cells. Among the composites, having CL/CH/C5 showed the highest cytotoxic effect and reduced survival rate of osteosarcoma cells to 75.68% after 24 h. The subsequent increase of CeO 2 concentration was also effective but its effect was less than CL/CH/C5 sample. Finally, cerium-doped nanobioactive glass/collagen/chitosan composites scaffolds were exhibited good biocompatibility on normal cells and increased cytotoxicity on cancer osteosaroma cells.