Platelet lysates promote mesenchymal stem cell expansion: A safety substitute for animal serum in cell-based therapy applications

TLDR

Mesenchymal stem cells are widely used for tissue repair and are conventionally expanded with fetal calf serum, which poses potential prion or viral contamination risks. The study aimed to evaluate platelet lysates as a safe, growth‑factor–rich alternative to fetal calf serum for expanding mesenchymal stem cells. Human MSCs were cultured and subcultured in media supplemented with either fetal calf serum (with or without bFGF) or platelet lysate. Platelet lysate–supplemented medium, rich in growth factors, accelerated MSC expansion, shortened confluence time, increased CFU‑F size, and preserved osteogenic, chondrogenic, adipogenic differentiation and immunosuppressive functions. © 2005 Wiley‑Liss, Inc.

Abstract

Mesenchymal stem cells (MSCs) are considered as emergent "universal" cells and various tissue repair programs using MSCs are in development. In vitro expansion of MSCs is conventionally achieved in medium containing fetal calf serum (FCS) and is increased by addition of growth factors. However, for widespread clinical applications, contact of MSCs with FCS must be minimized since it is a putative source of prion or virus transmission. Therefore, because platelets are a natural source of growth factors, we sought to investigate in vitro MSC expansion in response to platelet lysates (PL) obtained from platelet-rich plasma. Human MSCs were expanded in FCS (±bFGF)- or PL-supplemented medium through a process of subculture. We demonstrated that PL-containing medium is enriched by growth factors (platelet-derived growth factors (PDGFs), basic fibroblast growth factor (bFGF), transforming growth factor (TGF-β), insulin-like growth factor-1 (IGF-1) …) and showed that PL is able to promote MSC expansion, to decrease the time required to reach confluence, and to increase CFU-F size, as compared to the FCS medium. Furthermore, we demonstrated that MSCs cultured in the presence of PL maintain their osteogenic, chondrogenic, and adipogenic differentiation properties and retain their immunosuppressive activity. Therefore, we propose that PL may be a powerful and safe substitute for FCS in development of tissue- and cellular-engineered products in clinical settings using MSCs. © 2005 Wiley-Liss, Inc.