Lactoferrin network with MC3T3-E1 cell proliferation, auxiliary mineralization, antibacterial functions: A multifunctional coating for biofunctionalization of implant surfaces

Developing biocompatible, low-immunoreactive, and antibacterial implants are challenging yet fundamental to osteosynthesis. In this study, mineralization-stimulative and antibacterial networking nanostructures are assembled via amyloid-like aggregation of lactoferrin (LF) triggered by reducing the intramolecular disulfide bonds. Due to the adhesive property of their rich β-sheet architecture, the LF networks are amenable to the deposition upon the surface of various implant materials, functionalizing the implants with cell-proliferative, mineralization-stimulative, and antibacterial properties. Specifically, the abundant functional groups and amino acids exposed on the surface of LF networks provide abundant functional microdomains for subsequent mineralization of different forms of calcium ions and promote the formation of hydroxyapatite (HAp) crystals in simulated body fluids. We further demonstrate that the LF network inherits the innate antibacterial properties of LF and exerts a synergistic antibacterial ability with surface-enriched positively charged and hydrophobic amino acid residues, disrupting bacterial biofilm formation, enhancing microbial cell wall perturbation, and ultimately leading to microbial death. The results underscore the feasibility of the LF network as a multifunctional coating on bioscaffold surfaces, which may provide insight into its future applications in next-generation artificial bone implants with bacterial/biofilm clearance and bone tissue remodeling capabilities.