A Universal and Ultrastable Mineralization Coating Bioinspired from Biofilms

A simple and universal method for manufacturing a mineralization coating on various surfaces is developed using a biofilm‐based material obtained from engineered curli nanofibers. The amyloid protein (CsgA) is the main proteinaceous component in the Escherichia coli (E. coli) biofilm, which can withstand detergents in the harsh environment. The peptide sequence DDDEEK is bioinspired from salivary acquired pellicles in the dental plaque biofilm, having a strong ability to absorb mineral ions and induce the formation of biominerals. The bioinspired coating is successfully secreted by the engineered E. coli, which is transformed with a recombinant plasmid for expression with T7 promoter (PET), namely PET‐22b‐CsgA‐DDDEEK plasmid. The uniform coating can bear shear force and stay on virtually any type of material surface for at least one month. Moreover, the coated slices had a good mineralization performance and better stability than hydroxyapatite (HA)‐spray slices. Furthermore, MG63 cells on the bioactive HA layer induced by the coating possess a better growth capacity than those on the commercial product Matrigel. The animal experiment results suggest that the coated Ti6Al4V screws with induced HA present better osteogenicity and osseointegration than HA‐sprayed screws after 12 weeks, as well as no extra immunogenicity. Thus, the coating is highly promising for biomedical applications. CsgA‐DDDEEK is successfully expressed by BL21‐Gold (DE3) to form an amyloid fiber complex coating on diverse surfaces. The coated slices have a better mineralization performance. The bioactive hydroxyapatite layer induced by the coating can improve MG63 adhesion, proliferation, and osteodifferentiation. It can also promote the osteogenicity and osseointegration of bone screws.