3D printed step‐gradient composite hydrogels for directed migration and osteogenic differentiation of human bone marrow‐derived mesenchymal stem cells

Abstract

With the aid of a 3D printing technique, we create a 3D printed step‐gradient (nano)composite scaffold (GradS). GradS is generated by spatially connecting different (nano)composite hydrogel precursors varying in their concentrations of GelMA, alginate, and functional nanomaterials [DexPMO‐PDL = dexamethasone (Dex)‐ and poly‐d‐lysine (PDL)‐functionalized periodic mesoporous organosilicas (PMO)]. GradS not only allows for improving the viability of human bone marrow‐derived mesenchymal stem cells (hBM MSC), but GradS is also applied to direct the migration of hBM MSC toward the higher concentration of GelMA and nanomaterials (NMs) within the 3D gradient porous hydrogel network. Furthermore, we demonstrate that the osteogenic differentiation capacity of hBM MSC is promoted by an increase in the content of GelMA and DexPMO‐PDL; increasing concentrations of GelMA and DexPMO‐PDL within the GradS regulates the migration and subsequent osteogenic differentiation of hBM MSC within the 3D gradient hydrogel network.