Bioinspired Design of an Underwater Adhesive Based on Tea Polyphenol-Modified Silk Fibroin

Adhesives have garnered significant interest recently due to their application in the field of biomedical applications. Nonetheless, developing adhesives that exhibit robust underwater adhesion and possess antimicrobial properties continues to pose a significant challenge. In this study, motivated by the adhesive mechanism observed in mussels in aquatic environments, dopamine (DA) was added to modify the silk fibroin (SF) solution. Subsequently, tea polyphenol (TP) was incorporated to form a sticky mixture, resulting in a biomimetic adhesive (TP-DA/SF). TP-DA/SF demonstrated rapid, robust, and indiscriminate adhesion to a wide array of substrates and even biological tissues (39 kPa). TP-DA/SF exhibits the ability to replicate the mussel adhesion mechanism of mussels underwater thanks to its biomimetic design. This characteristic provides the material with robust adhesion (40 kPa), notable reusability (at least 10 times), and long-lasting stability, especially in aquatic settings. It is worth noting that TP-DA/SF also demonstrated high adhesion in various water environments, even in solutions with a pH of 7.4 and buffered saline (PBS), which is one of the most widely used buffers in biochemistry research, offering salt-balancing and adjustable pH buffering capabilities. Meanwhile, TP-DA/SF exhibits excellent antibacterial and antioxidant properties due to its tea polyphenol content. After 15 days of wound closure in SD rats, the healing rate in the experimental group reached 93.4%, compared to 83.9% in the control group. Thus, the TP-DA/SF adhesive holds promising potential for biomedical applications, including sutureless wound closure and tissue adhesion.