Universal Manufacturing of Multifunctional Composite Coatings with Integrated Anticorrosion, Super-Lubrication, and Antibacterial Properties for Diverse Metallic Substrates

The manufacture of biocompatible multifunctional medical metal materials constitutes a frontier challenge. Meanwhile, surface modification offers substantial potential for enhancing their functionality and broadening their application scope. Nevertheless, it remains crucial to customize and modify the surface of medical metal materials to endow them with multiple functionalities, including anticorrosive, antibacterial, and wear-resistance properties. In this study, we designed a new concept and realized the successful manufacture of a multifunctional composite coating with a hierarchical structure on diverse medical metal substrates, including CoCrMo, Ti6Al4V, and 316L. This composite coating system consists of a hard diamond-like carbon (DLC) layer serving as a corrosion barrier, an intermediate silica sol layer incorporating both reactive initiators and antibacterial agents for load-bearing, and a top-soft hydration layer composed of polysulfobetaine methacrylate (PSPMA) brush for friction reduction. The as-manufactured composite coating exhibits superior hydrophilicity, excellent corrosion resistance, as well as durable super-lubrication properties in diverse media. This manufacture concept has been validated on curved 316L artificial hip joint femoral head. Notably, the composite coating can even maintain a stable and super-low coefficient of friction (COF: ∼0.0035) on the surface of three kinds of metal substrates after encountering 50,000 friction sliding cycles, as well as ignorable wear. Furthermore, the composite coating demonstrates outstanding antibacterial performance against Gram-positive Staphylococcus aureus (S. aureus). This work presents a novel manufacture strategy for the design and development of multifunctional implantable/interventional metallic materials and devices, holding great promise for biomedical engineering applications.