Interfacial Confined Oxidation‐Assisted Construction of Black Bioceramic Coating on Metal Implants for Therapy and Regeneration by On‐Demand Remodeling Pathological Microenvironment

Abstract The commonly used metal bone implants fail to specifically modulate pathological microenvironments to exert therapeutic or reparative efficacy in tricky diseases such as osteosarcoma. Herein, a novel “Interfacial confined oxidation” (ICO) strategy has been proposed to construct black bioceramic coating on various metal implants for ondemand remodeling of osteosarcoma pathological microenvironment. The ICO strategy leverages the confined oxidation of liquified bioactive glass with low transition temperature to in situ construct black bioceramic coating composed of metal suboxides and bioactive oxides without high‐vacuum reducing atmosphere conditions. The as‐prepared black bioceramic coating could generate an alkaline microenvironment containing bioactive ions to promote bone formation. In addition, the alkalinity of the microenvironment generated by this coating can be enhanced by near‐infrared light stimulation, which exhibits potent tumor inhibition through apoptosis induction and immune activation, and antibacterial activity via interfering with ATP synthesis and triggering oxidative stress. This study provides a simple and universal strategy for the construction of black bioceramic coating for therapy and regeneration, which has a prominent clinical application prospect on the modification of metal implants.