Bovine Serum Albumin Crosslinked Hydrogels with Enhanced Mechanical Properties for Skin Bioelectronics

The applications of hydrogel in the field of skin bioelectronics are rapidly expanding, and the development of hydrogels with both superior mechanical properties and strong adhesion is critical for facilitating their clinical translation. Here, a protein crosslinking strategy is reported, in which modified bovine serum albumin (BM) is used as a crosslinker to synthesize highly stretchable and strongly adhesive protein hydrogels. On the one hand, BM molecules form dual physical and chemical crosslinking interactions, and the secondary structures within BM can establish a spring-like energy dissipation mechanism, thereby significantly enhancing the mechanical properties of the hydrogel. On the other hand, BM provides abundant functional groups, including amino, carboxyl, and hydroxyl groups, which can effectively improve the adhesion of the hydrogel to biological tissues and various solid surfaces. Furthermore, BM is applicable to multiple hydrogel systems, demonstrating a certain degree of universality. Leveraging the hydrogel's high stretchability and strong adhesion, its effectiveness has been demonstrated in skin bioelectronics including strain sensors, electrocardiogram/electromyogram monitoring, and electrical stimulation therapy, due to the conductivity, transparency, and biocompatibility. This series of studies expands the clinical application scope of hydrogels, provides inspiration for the integration of treatment and intelligent monitoring, and enhances the everyday practicality of hydrogels.