LAUSR

Silk sericin has excellent features of antioxidant ability and good cytocompatibility; however, high water solubility and poor mechanical properties have restricted its application in biomedical fields. In this study, aimed at improving the mechanical properties of a regenerated silk sericin, the primary hydroxy groups in silk sericin were enzymatically oxidized by using laccase and 2,2',6,6'‐tetramethylpiperidine‐N‐oxyl (TEMPO), and the generated reactive groups then reacted further with the amino groups in the sericin chains. The efficacy of the enzymatic cross‐linking was evaluated by means of determination of amino groups, SDS polyacrylamide gel electrophoresis, Fourier transform infrared (FTIR) spectroscopy, and size exclusion chromatography. The results indicated that either laccase/TEMPO incubation or laccase treatment alone incurred a noticeable increase in the molecular weight of the sericin. FTIR analysis revealed that there was small change in the structure of the silk sericin after laccase/TEMPO treatment, and the obtained air‐dried sericin membrane exhibited remarkably improved mechanical properties relative to those of the uncross‐linked sericin membrane. In addition, the biocompatibility of the sericin membrane was at an acceptable level according to the cell viability of NIH/3T3 cells. The present work provides a novel method for the preparation of sericin‐based biomaterials.