Biomimetically Mineralized Hydrogel Coating Functionalized with Calcium Phosphate Oligomers Enhances Osteogenic Differentiation

The complex pathological environment of osteoporotic bone defects makes the induction of bone regeneration challenging. This study proposes an organic–inorganic composite hydrogel coating for modifying the surface of poly(aryl ether sulfone ketone) (PPESK) implants. The hydrogel coating, which mainly comprises organic acrylamide monomers with calcium phosphate oligomers (CPOs) introduced to interact with organic matter, was prepared via biomimetic mineralization in a simulated body fluid containing strontium. The introduction of CPOs significantly enhanced the mineralization capacity of the hydrogel coating, forming a dense apatite layer and achieving deep mineralization throughout the hydrogel matrix. In vitro experiments demonstrated that the hydrogel coating could significantly promote the proliferation of MC3T3-E1 cells on a chemically modified PPESK surface and the expression of osteogenesis-related genes. The proposed hydrogel coating exhibited good osteogenic activity and effectively promoted bone regeneration, demonstrating promising application prospects for PPESK bone implants in the field of osteoporotic bone defect repair.