The pits and fissures of teeth have high caries susceptibility, and sealing these areas is considered as an effective method to prevent caries. However, long-term caries prophylaxis cannot be maintained because of the negative effects derived from the technical sensitivity and disadvantages of sealing materials. Herein, a new strategy is proposed to occlude fossae by amyloid-mediated biomimetic remineralization. In contrast to conventional inward blocking from the outside of fossae, amyloid-mediated biomimetic mineralization delivers an amyloid-like protein nanofilm into the deepest zone of the fossae and induces the formation of remineralized enamel inside. Such assembly from lysozyme conjugated with poly (ethylene glycol) enriches the interface with strongly bonded ionsand directs in situ nucleation to achieve enamel epitaxial growth. Not only is the structure of the enamel-like crystalline hydroxyapatite layer but also its mechanical stability is similar to that of natural enamel. Furthermore, the layer shows good biocompatibility and antibacterial properties. On the basis of the findings, it is demonstrated that amyloid-like protein aggregation may provide an enamel remineralization strategy to modify the current clinically available methods of pit and fissure sealing and shows great promise in preventing caries.

The extensive use of detergents in modern life and industry has seriously impeded ecologically sustainable development. Facing this unresolved global challenge, we herein propose a CAW (coating at will) concept to endow virtually arbitrary surfaces with underwater superoleophobicity that supports the fast and easy removal of oily stains by mere use of water. The key selling point of this CAW concept is its ability to sustainably regenerate the coating throughout an infinite life cycle. The foundation of this concept is to make use of rapid amyloid-like aggregation of lysozyme (Lyz) conjugated with zwitterionic poly(sulfobetaine methacrylate) (pSBMA). The resultant phase-transitioned Lyz-pSBMA (PTL-pSBMA) could quickly prime versatile surfaces to afford a robust colourless ultrathin nanofilm on surfaces with high hydrophilicity. As a result, the hydrophilic PTL-pSBMA layer endows materials with excellent underwater superoleophobicity and provides outstanding detergent-free cleaning efficiency to remove oily stains (e.g., greater than 95% on silk surfaces and 99% on dishes). With excellent optical transparency, biocompatibility and negligible effects on wearing comfort, the PTL-pSBMA further showed extraordinary cost-effectiveness ($675/ton) and great savings on water and energy by 40%-50%. Overall, this work proposes an ingenious CAW design that breaks down the long-standing surfactant contamination barriers in the traditional detergent industry. Such surfactant-free water washing strategy holds great promise towards scale-up application to replace commercial detergents in the removal of common stains from fabrics and kitchenware surfaces, thereby greatly inhibiting the negative environmental pressures caused by surfactant emissions and providing a transformative response to ecosystems and water resource protection on Earth.

Proteins have been adopted by natural living organisms to create robust bioadhesive materials, such as biofilms and amyloid plaques formed in microbes and barnacles. In these cases, β-sheet stacking is recognized as a key feature that is closely related to the interfacial adhesion of proteins. Herein, we challenge this well-known recognition by proposing an α-helix-mediated interfacial adhesion model for proteins. By using bovine serum albumin (BSA) as a model protein, it was discovered that the reduction of disulfide bonds in BSA results in random coils from unfolded BSA dragging α-helices to gather at the solid/liquid interface (SLI). The hydrophobic residues in the α-helix then expose and break through the hydration layer of the SLI, followed by the random deposition of hydrophilic and hydrophobic residues to achieve interfacial adhesion. As a result, the first assembled layer is enriched in the α-helix secondary structure, which is then strengthened by intermolecular disulfide bonds and further initiates stepwise layering protein assembly. In this process, β-sheet stacking is transformed from the α-helix in a gradually evolving manner. This finding thus indicates a valuable clue that β-sheetfeaturing amyloid may form after the interfacial adhesion of proteins. Furthermore, the finding of the α-helix-mediated interfacial adhesion model of proteins affords a unique strategy to prepare protein nanofilms with a well-defined layer number, presenting robust and modulable adhesion on various substrates and exhibiting good resistance to acid, alkali, organic solvent, ultrasonic, and adhesive tape peeling.

A poor seal of the titanium implant–soft tissue interface provokes bacterial invasion, aggravates inflammation, and ultimately results in implant failure. To ensure the long‐term success of titanium implants, lactoferrin‐derived amyloid is coated on the titanium surface to increase the expression of cell integrins and hemidesmosomes, with the goal of promoting soft tissue seal and imparting antibacterial activity to the implants. The lactoferrin‐derived amyloid coated titanium structures contain a large number of amino and carboxyl groups on their surfaces, and promote proliferation and adhesion of epithelial cells and fibroblasts via the PI3K/AKT pathway. The amyloid coating also has a strong positive charge and possesses potent antibacterial activities against Staphylococcus aureus and Porphyromonas gingivalis. In a rat immediate implantation model, the amyloid‐coated titanium implants form gingival junctional epithelium at the transmucosal region that resembles the junctional epithelium in natural teeth. This provides a strong soft tissue seal to wall off infection. Taken together, lactoferrin‐derived amyloid is a dual‐function transparent coating that promotes soft tissue seal and possesses antibacterial activity. These unique properties enable the synthesized amyloid to be used as potential biological implant coatings.

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