Bioinspired nano-painting on orthopedic implants orchestrates periprosthetic anti-infection and osseointegration in a rat model of arthroplasty

Periprosthetic joint infection (PJI) is the most serious and catastrophic complication after artificial arthroplasty. The bacteria-mediated immunosuppressive microenvironment adversely affects the osseointegration of orthopedic implants, which can lead to implant malfunction even failure. Herein we developed a PJI self-sensitive bioinspired nano-painting on the orthopedic implant for combating the bacterial infection and promoting osseointegration. The house-made CaO2 nanoparticles were first polyphenol-functionalized with tannic acid (TA) and deposited on titanium implant by interfacial molecular interactions of mussel-bioinspired adhesion, and then interparticle-locked in a Cu2+ ion-facilitated metal-phenolic network. Once infection occurred, the bioinspired nano-painting on the implant rapidly disassembled upon the triggering of the acidic niche that induced by the bacterial metabolism. The CaO2-initiated O2 release relieved the hypoxia in the infected microenvironment, and induced pro-inflammatory polarization of locoregional macrophages through synergizing with Cu2+ ions. Our data demonstrated that the bioinspired nano-painting significantly prevented periprosthetic joint infection and promoted the peri-implant osteogenesis through aborting the immunosuppressive milieu in an arthroplasty rat model. The bioinspired nano-painting technology may therefore provide a practical approach for orchestrating the prevention of periprosthetic joint infection and the osseointegration for patients that undergo artificial arthroplasty.