PGCAP improves osteogenic differentiation of mesenchymal stromal cells (MSCs) loaded on biomaterials. Total RNAs were extracted from ni-MSCs and i-MSCs loaded on BMA and BMF at high cell seeding density (200 × 103 cells per biomaterial) embedded or not in PGCAP and grown for 21 days. Quantifications of osteopontin, type I collagen, Runx2, osteonectin, osteocalcin, and alkaline phosphatase mRNA expression were analyzed by real-time quantitative-polymerase chain reaction. Transcript levels in arbitrary units are expressed as mean ± standard error of the mean. A statistically significant difference between individual conditions or groups of condition was revealed by analysis-of-variance test followed by Student Newman-Keuls test. Osteopontin: group of ni-MSCs and i-MSCs loaded on BMA embedded in PGCAP was compared with other conditions ($*P <0.05). Type I collagen: individual comparisons, *P <0.05, **P <0.01, ***P <0.001. Runx2, Osteonectin: group with ni-MSCs embedded in PGCAP (loaded in both biomaterials) was compared with other conditions with i-MSCs (#*P <0.05). Osteocalcin: comparison of group osteogenic-induced or not (£*P <0.05). Alkaline phosphatase: group with i-MSCs without PGCAP (loaded in both biomaterials) was compared with other conditions with ni-MSCs (§**P <0.01). i-MSC, not osteogenic induced-mesenchymal stromal cell; ni-MSC, not induced-mesenchymal stromal cell; PGCAP, platelet glue obtained from cryoprecipitation of apheresis platelet products.