Physical characteristics and biocompatibility of biomaterials and mesenchymal stromal cell (MSC) proliferation on the different biomaterials. (a) Representative scanning electron microscopy images of 'Calciresorb' (BMA) and 'Calciresorb bone like' (BMF) biomaterial surfaces are shown. MSCs were loaded on these two biomaterials and grown in platelet lysate (PL) medium. MSC colonization on the various biomaterials was evaluated by scanning electron microscopy at 14 days of culture. Arrows indicate cells on biomaterials. (b) MSCs loaded on the various biomaterials at low cell seeding density (100 × 103 cells per biomaterial) were grown in PL medium for 14 days. The number of cells on the different biomaterials was evaluated at days 4, 7, and 14. The data are expressed as mean ± standard error of the mean. A statistically significant difference between individual conditions was revealed by analysis-of-variance test followed by Student Newman-Keuls test. **P <0.01, ****P <0.0001. d, day.