INFLUENCE OF DONOR AGE ON OSTEOGENIC DIFFERENTIATION AND CELL SHEET FORMATION IN BONE MARROW-DERIVED MESENCHYMAL STEM CELLS

Abstract

This study aimed to compare the in vitro osteogenic differentiation potential and cell sheet-forming capacity of rat bone marrow-derived mesenchymal stem cells (rBMSCs) isolated from 4-week-old (wk-old) and 14-wk-old Wistar rats. rBMSCs were obtained from tibias and femurs and characterized by flow cytometry. Osteogenic differentiation potential was assessed by alkaline phosphatase (ALP) activity and Alizarin Red staining. rBMSCs from both groups were cultured on temperature-responsive plates to develop cell sheets. Sheet structure and detachment were assessed. Over 95% of adherent rBMSCs were positive for CD29, CD44, and CD90, and negative for CD45. rBMSCs from 4-wk-old rats exhibited significantly higher osteogenic differentiation potential, as indicated by increased ALP activity (P < 0.05) and mineralized nodules formation, whereas rBMSCs from 14-wk-old rats showed no mineralization. In contrast, only 14-wk-old rBMSCs successfully formed intact and detachable cell sheets, while 4-wk-old rBMSCs did not form cohesive sheets. In conclusion, donor age significantly influences rBMSC behavior. 4-wk-old rBMSCs exhibit enhanced osteogenic differentiation potential, whereas 14-wk-old rBMSCs demonstrate superior cell sheet formation efficacy. Further studies are needed to optimize sheet formation of younger donors.