Fabrication, Structural Characteristics, and Properties of Sericin-Coated Wool Nonwoven Fabrics.

Recently, nonwoven fabrics from natural silk have attracted considerable attention for biomedical and cosmetic applications because of their good mechanical properties and cytocompatibility. Although these fabrics can be easily fabricated using the binding character of sericin, the high cost of silk material may restrict its industrial use in certain areas. In this study, sericin was added as a binder to a cheaper material (wool) to prepare wool-based nonwoven fabrics and investigate the effect of the amount of sericin added on the structural characteristics and properties of the wool nonwoven fabric. It was found using SEM that sericin coated the surface of wool fibers and filled the space between them. With an increase in sericin addition, the porosity, moisture regain, and the contact angle of the sericin-coated wool nonwoven fabric decreased. The maximum stress and initial Young's modulus of the nonwoven fabric increased with the increase in sericin amount up to 32.5%, and decreased with a further increase in the amount of sericin. Elongation at the end steadily decreased with the increase in sericin addition. All of the nonwoven fabrics showed good cytocompatibility, which increased with the amount of sericin added. These results indicate that sericin-coated wool-based nonwoven fabrics may be successfully prepared by adding sericin to wool fibers, and that the properties of these fabrics may be diversely controlled by altering the amount of sericin added, making them promising candidates for biomedical and cosmetic applications.

Structural Characteristics and Properties of Redissolved Silk Sericin.

Silk sericin has garnered the attention of researchers as a promising biomaterial because of its good biocompatibility and high water retention. However, despite its useful properties, the poor storage stability of sericin has restricted its extensive use in biorelated applications. This study extracted sericin from silkworm cocoon, dried and stored it as a solid, and then dissolved it in hot water conditions to improve the storage stability of sericin for its use. The dissolution behavior of the extracted sericin solids was examined in conjunction with the structural characteristics and properties of dissolved sericin. Consequently, the results of solution viscosity, gel strength, crystallinity index, and thermal decomposition temperature indicated that the molecular weight (MW) of the dissolved sericin remained constant until a dissolution time of 5 min, following which deterioration was observed. The optimum condition of dissolution of the extracted sericin solid was 5 min at 90 °C. Conclusively, the extracted sericin could be stored in a dry state and dissolved to prepare redissolved sericin aqueous solution with the same MW as extracted sericin, thereby improving the storage stability of the sericin aqueous solution.