Aqueous-based electrospinning of regenerated Antheraea pernyi silk fibroin

Antheraea pernyi silk fibroin (ASF) nanofibers, with good biocompatibility and biodegradability, have promising potential for biomaterial applications. However, the concentration processing of ASF solution for improving spinnability to achieve aqueous-based electrospinning remains a challenge. In this study, to avoid complicated concentration processing we demonstrated that lyophilized ASF possesses good water-solubility to generate highly concentrated ASF solution. The lyophilized ASF can be stored for a long time without structural changes and was able to re-dissolve to form reconstituted solution, providing a facile approach for the preparation of high concentration ASF solution. To avoid the gelation, refrigeration at 4 oC can keep reconstituted ASF solution stable for long-term storage before electrospinning. It was found that the reconstituted ASF solution from lyophilized ASF solid exhibited good spinnability for uniform nanofiber formation when the concentration reached to 28.6 wt%, and a lower environmental temperature is preferential for prolonged electrospinning. Although a low concentration ASF aqueous solution was not electrospun into nanofibers, the solution could be fabricated into microspheres by electrospraying in a liquid nitrogen bath. The simple aqueous-based electrospining of ASF provides useful options for the fabrication of ASF biomaterials.