Molecularly Imprinted Macroporous Hydrogel Promotes Bone Regeneration via Osteogenic Induction and Osteoclastic Inhibition.

Macroporous hydrogels offer physical supportive spaces and bio-instructive environment for the seeded cells, where cell-scaffold interactions directly influence cell fates and subsequently affect tissue regeneration post-implantation. Effectively modifying bioactive motifs at the inner pore surface provides appropriate niches for cell-scaffold interactions. A molecular imprinting method and sacrificial templates are introduced to prepare inner pore surface modification in the macroporous hydrogels. In detail, acrylated bisphosphonates (Ac-BPs) chelating to templates (CaCO particles) are anchored on the inner pore surface of the methacrylated gelatin (GelMA)-methacrylated hyaluronic acid (HAMA)-poly (ethylene glycol) diacrylate (PEGDA) macroporous hydrogel (GHP) to form a functional hydrogel scaffold (GHP-int-BP). GHP-int-BP, but not GHP, effectively crafts artificial cell niches to substantially alter cell fates, including osteogenic induction and osteoclastic inhibition, and promote in situ bone regeneration. These findings highlight that molecular imprinting on the inner pore surface in the hydrogel efficiently creates orthogonally additive bio-instructive scaffolds for bone regeneration.