Amylopectin Multiple Aldehyde Crosslinked Hydrogel as an Injectable and Self-Healing Cell Carrier for Bone Tissue Engineering

Despite excellent processing and biological properties of gelatin for use as a cell carrier, none of the gelatin-based hydrogel cell carriers reported to date offer all characteristics including quick formation, injectability, self-healing, and durability, which are simultaneously required for an ideal system. Here, a gelatin-based hydrogel with dynamic Schiff base linkages, so-called dynamic hydrogel, as an injectable cell carrier consisting of gelatin and amylopectin multiple aldehyde (AMPA), with all the required characteristics is reported. Biocompatibility and osteoinductivity of the hydrogel are verified through the culture of human bone marrow-derived mesenchymal stem cells (hBMSCs). As live/dead results show, hBMSCs are alive and highly viable approximate to 85-90% within the hydrogel after 5 days. According to bromodeoxyuridine cell proliferation assay, a significant increase in the number of the cells seeded in the hydrogel confirms its clinical significance for cell therapy. Most importantly, histological visualization using Mason's Trichrome staining indicates secretion of extracellular matrix around the cells loaded in the hydrogel and also expression level evaluation of the crucial osteogenic markers, confirms that the hydrogel can provide osteoinductive support for osteocyte differentiation of hBMSCs after 14 days. Therefore, this hydrogel provides more progress on the path toward bone tissue engineering and further treatment of bone diseases.