Controlled release of PRP-derived growth factors promotes osteogenic differentiation of human mesenchymal stem cells.

Platelet-rich plasma (PRP) has been gaining increasing popularity in orthopedics and oral and maxillofacial surgery because of its potential efficacy in enhancing bone regeneration. To maximally augment bone healing using PRP and to control the bioavailability of the relevant growth factors, we have designed an alginate hydrogel-based PRP-delivery system. The bioactivity of the growth factors released from PRP carriers was evaluated by determining the ability of these factors to induce osteogenic differentiation of human mesenchymal stem cells (hMSCs). Specifically, monolayers of hMSCs were incubated with the PRP-containing hydrogel carriers over a two-week culture period. Osteoblast-like cells treated with the hydrogel carriers served as controls. The growth and osteogenic differentiation (alkaline phosphatase activity and mineralization) of hMSCs was determined. The results showed that PRP-derived growth factors released from hydrogel carriers stimulated the osteogenic differentiation of hMSCs and most significantly, the cellular response was carrier type-dependent. Future studies will focus on in vitro and in vivo testing of the efficacy of hydrogel-based PRP release systems.