3D-printed porous calcium silicate scaffolds with hydroxyapatite/graphene oxide hybrid coating for guided bone regeneration

Calcium silicate (CS) is a suitable bone repair material due to its bioactivity and biocompatibility. However, its rapid degradation rate and poor cell response affect the bone regeneration process. Surface modification of implants represents a potent strategy for enhancing the performance of biomaterials. Here, we present a novel method combining hydrothermal treatment and chemical grafting to tailor the surface morphology and composition of 3D-printed calcium silicate porous scaffolds. The resulting scaffold surface features hydroxyapatite (HA) nanosheets and graphene oxide (GO) sheet structures. Surface modification significantly reduced the degradation rate of CS scaffolds and decreased the Si ion concentration after PBS immersion, which was more conducive to cell survival. Our findings reveal that the CS/HA/GO scaffold exhibits superior biocompatibility and significantly enhances cell adhesion, proliferation, and osteogenic differentiation. In vivo studies demonstrate that the CS/HA/GO scaffold markedly promotes the regeneration of defective bone tissue. This work highlights the potential of HA and GO coatings on interconnected porous scaffolds to induce bone tissue regeneration, offering a promising strategy for orthopedic applications.