Comparative study of the effect of fresh platelet lysate and lyophilized platelet lysate on human mesenchymal stem cell proliferation and apoptosis

Abstract

Mesenchymal stem cells (MSCs) can differentiate into a wide range of cell types. MSCs hold significance in cell therapy and regenerative medicine. FBS has been the main supplement in MSC culture but there are several issues with FBS usage including undefined composition, allergic reactions, and prion/zoonotic transmission possibility.Human platelet lysate (hPL) is an alternative to FBS as a source of different growth factors that can promote MSC proliferation but there are many drawbacks to using fresh hPL, including poor stability, challenging shipping, and storage conditions. The recommended solution is to freeze-dry fresh hPL. Aims:This study compares the impact of fresh and lyophilized hPL on hMSC proliferation and apoptosis after six months. Methods:Fresh PL was prepared from PRP via consecutive freeze-thaw cycles, and then fresh PL was lyophilized to prepare lyophilized PL. SDS-PAGE and silver nitrate staining were used to assess the impact of different numbers of consecutive freeze-thaw cycles and also lyophilization effects on the PL proteins. The following MTT assays were used to determine the impact of fresh/frozen, lyophilized PL on the viability of MSCs. Also, annexin V/PI staining and flow cytometric analysis were used to compare the anti-apoptotic effects of them on MCSs.Results: Three consecutive freeze-thaw cycles are sufficient to produce platelet lysate.PL proteins' physical integrity was maintained by freeze-drying.Lyophilized forms of PL samples were more effective in promoting the proliferation of MSCs than the frozen samples after six months. All PL samples, aside from frozen PL in PBS, enhanced MSC proliferation either more than or similarly to FBS after six months of storage. Also, different forms of PL didn't have significant differences in inducing anti-apoptotic effects on cells. Conclusion:According to the results, freeze-drying can be a suitable method for industrial-scale production of PL.