Design of strong and tough biofibers and their biomedical applications

Strong and tough biofibers, which have comparable mechanical performances with conventional synthetic fibers derived from petrochemicals, have demonstrated superior advantages in sustainability and biocompatibility and have provided innovative solutions for various areas over synthetic fibers. Studies on strong and tough biofibers have addressed the growing demand for sustainable products and biomedical applications. Here, recent advances in strong and tough biofibers are summarized and discussed, including their materials, spinning methods, strengthening strategies, and various applications. Four natural materials commonly used for biofibers are introduced first, including spider silk, silkworm silk, chitin, and cellulose, and then four different spinning techniques developed to prepare strong and tough biofibers are summarized, including dry spinning, wet spinning, 3D printing, and microfluidic spinning. Strengthening strategies, such as dual crosslinking and post treatment, are applied to further improve the mechanical performances of biofibers, and their applications, especially in clothing, suture, would dressing, tissue engineering, and sensor, are discussed in detail. Continuous innovations in strong and tough biofibers hold a great promise for driving further advancements and offering solutions to related global challenges.