Graphene Oxide and Lysozyme Ultrathin Films with Strong Antibacterial and Enhanced Osteogenesis

There is a great demand worldwide for bone-related implant materials. The drawbacks of chronic infections and poor bone healing of current implant materials have limited their clinical applications. Functionalizing the implant surfaces with antibacterial and osteogenic films on implant materials provides new opportunities for fabricating novel implant materials. In the present study, an ultrathin (GO/Lys)8 film of several tens of nanometers was fabricated using a layer-by-layer (LBL) technique with alternative deposition of graphene oxide (GO) and lysozyme (Lys). The deposition of the (GO/Lys) n film exhibited a successive growth as supported by ellipsometry, UV-vis, and Fourier transform infrared data, and the physical properties (morphology, roughness, and stiffness) of this film were characterized with an atomic force microscope. The ultrathin films exhibited a great effect on bacterium sterilization of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli and enhanced osteogenic differentiation efficiency, showing the potential application in bone implant coatings. We believe that this LBL assembling strategy will pave the way for fabricating dual-functional surfaces and guide the design of the implanted surfaces in the future.