Graphene Oxide and Adiponectin-Functionalized Sulfonated Poly(etheretherketone) with Effective Osteogenicity and Remotely Repeatable Photodisinfection

Biomaterial-associated infection (BAI) is a serious threat to patients' health. In general, bacteriostatic agents are loaded on the surface of biomaterials to eliminate BAI; however, the excessive usage of these agents leads to the emergence of drug-resistant bacteria and inadequacy of tissue repair. To address this issue, here, we create a photoresponsive and osteopromotive coating that consists of graphene oxide (GO) nanosheets, polydopamine (pDA) nanolayers, and adiponectin (APN) protein on bioinert sulfonated poly(etheretherketone) (sPEEK/GO/APN). The functionalized samples display superior cytocompatibility and in vitro osteogenicity regarding cell reproduction, spreading, alkaline phosphatase activity, extracellular matrix calcification, and osteo-associated genes expression, outperforming sPEEK/GO and sPEEK/APN samples. The in vivo evaluation using a rabbit femur defect model demonstrates that the multifunctional coating significantly boosts bone regeneration and osseointegration. More importantly, the GO/pDA complex bonded together through pi-pi stacking and electrostatic interactions gives rise to robust cyclic photothermal bacteria-killing ability toward both Gram-positive and Gram-negative bacteria. Such a surface engineering platform may enable biomedical implants with enhanced osteogenetic ability and remotely recyclable photodisinfection, holding great potential in the treatment of incurable infective bone loss.