Cumulative population doublings of MSC after culture in FBS, HPLF or HPLO.

MSC were cultured in culture media supplemented with 10% of FBS, platelet lysate from fresh platelet concentrates (HPLF) or lysate from expired platelet concentrates (HPLO). Population doubling assay was performed at the end of every passage for a total of six passages (P1–P6, n = 3). MSC cultured in either HPLF or HPLO consistently had higher numbers of population doublings at the end of every passage compared to MSC cultured in FBS. By the end of the sixth passage cumulative population doublings were 13.77±0.77 CPD for HPLO, 12.77±0.12 CPD for HPLF and 9.50±1.14 CPD for FBS supplemented cultures, respectively.