Design of a genetically programmed barnacle-curli inspired living-cell bioadhesive

In nature, barnacles and bacterial biofilms utilize self-assembly amyloid to achieve strong and robust interface adhesion. However, there is still a lack of sufficient research on the construction of macroscopic adhesives based on amyloid-like nanostructures through reasonable molecular design. Here, we report a genetically programmed self-assembly living-cell bioadhesive inspired by barnacle and curli system. Firstly, the encoding genes of two natural adhesion proteins (CsgA and cp19k) derived from E. coli curli and barnacle cement were fused and expressed as a fundamental building block of the bioadhesive. Utilizing the natural curli system of E. coli, fusion protein can be delivered to cell surface and self-assemble into an amyloid nanofibrous network. Then, the E. coli cells were incorporated into the molecular chain network of xanthan gum (XG) through covalent conjugation to produce a living-cell bioadhesive. The shear adhesive strength of the bioadhesive to the surface of the aluminum sheet reaches 278 ​kPa. Benefiting from living cells encapsulated inside, the bioadhesive can self-regenerate with adequate nutrients. This adhesive has low toxicity to organisms, strong resistance to the liquid environment in vivo, easy to pump, exhibiting potential application prospects in biomedical fields such as intestinal soft tissue repair.