Charge-Conversion-Induced Complexation Toughening of Adaptive and Degradable Protein Optical Fibers for Interventional Cancer Therapy

Protein hydrogel fibers hold great promise for diverse applications. However, the challenge lies in developing rapid and straightforward methods for the one-step fabrication of high-performance protein-based hydrogel optical fibers. Here, we present a general charge-conversion-induced complexation toughening (CCICT) strategy for preparing protein hydrogel fibers in 15 s. The in situ introduction of polyelectrolyte–micelle complexes enhances the fibers’ mechanical, antiswelling, and antibacterial properties. The protein components confer biocompatibility, enzymatic degradability, and strong tissue adhesion to the hydrogel fibers. Furthermore, the as-prepared fibers demonstrate excellent optical transmission with minimal attenuation of 0.15–0.50 dB cm^–1 across various wavelengths. The hierarchical multinetwork structure imparts outstanding adaptability and stability in mechanical and optical performance. Also, the protein fibers effectively deliver light for interventional photothermal cancer therapy beneath the skin of mice. Their rapid degradation in physiological environments promotes efficient wound healing. Therefore, this developed CCICT approach and these high-performance protein fibers are anticipated to have broad applications.