Self-assembled nanocomposite hydrogels driven by bisphosphonate-Mg~(2+) coordination regulate the differentiation of encapsulated stem cells and promote in-situ bone regeneration

摘要

Collectively, we demonstrate a self-assembled nanocomposite hydrogel driven by the bisphosphonate-Mg~(2+) coordination. The in situ self-assembled Ac-BP-Mg nanoparticles formed by this dynamic coordination function as effective multivalent crosslinkers, and the obtained hydrogels exhibit enhanced mechanical properties as well as excellent injectability and self-healing characteristics. Such hydrogels can be further crosslinked via the photopolymerization of acrylate groups on the surface of the embedded Ac-BP-Mg NPs, resulting in increased stiffness and crosslinking density. Furthermore, we investigate the response of encapsulated hMSCs to the dynamic stiffening of hydrogels, and we find that the early introduction of this secondary crosslinking inhibits cell spreading and osteogenesis. Finally, such hydrogels can promote the osteogenic differentiation of hMSCs as well as in situ bone regeneration.