Genipin stabilized fibrin microbeads: Carrying cytokines to form niches for stem cell differentiation

Niches, which are combinations of extracellular matrix and cytokines, play essential roles in the stem cell biology. In this study, genipin stabilized fibrin microbeads (gFMBs) were prepared through oil emulsion method. Then, sonic hedgehog (SHH) was crosslinked to the surface of gFMBs by using genipin. These gFMBs were designated as gFMB@SHH since SHH was attached to their surface. Moreover, ectomesenchymal stem cells (EMSCs) were cultured, characterized, and used to test gFMB@SHH. Genipin not only changed the color of fibrin microbeads (FMBs) to deep blue, but also stabilized FMBs by delaying their degradation in vitro. In addition to the nontoxic and proliferation promoting effects of gFMB@SHH on EMSCs, gFMBs@SHH could induce neural differentiation of EMSCs by stimulating the SHH/Gli pathway. Therefore, genipin stabilized fibrin microbeads might be a promising structure to construct niches for in vitro stem cell researches.