Mechanisms and Control of Silk-Based Electrospinning

Abstract

Silk fibroin (SF) nanofibers, formed through electrospinning, have attractive utility in regenerative medicine due to the biocompatibility, mechanical properties and tailorable degradability. The mechanism of SF electrospun nanofiber formation was studied to gain new insight into the formation and control of nanofibers. SF electrospinning solutions with different nanostructures (nanospheres or nanofilaments) were prepared by controlling the drying process during the preparation of regenerated SF films. Compared to SF nanospheres in solution, SF nanofilaments had better spinnability with lower viscosity when the concentration of silk protein was below 10%, indicating a critical role for SF morphology, and in particular, nanostructures for the formation of electrospun fibers. More interesting, the diameter of electrospun fibers gradually increased from 50 nm to 300 nm as the increase in concentration of SF nanofilaments in the solution from 6% to 12%, implying size control by simply adjusting SF nanostructure and concentration. Aside from process parameters investigated in previous studies, such as SF concentration, viscosity and electrical potential, the present mechanism emphasizes significant influence of SF nanostructure on spinnability and diameter control of SF electrospun fibers, providing a controllable option for the preparation of silk-based electrospun scaffolds for biomaterials, drug delivery and tissue engineering needs.

Silk Reconstitution Disrupts Fibroin Self-Assembly

“…All natural spider and silkworm silks appear to display a nanofibrillar substructure, and there is ample evidence that these fibrils contribute significantly to the prodigious mechanical properties of silks. 64,65 Assembly of RSF into fibrils with native-like structure has been demonstrated; 34,[38][39][40][41]43,44,54,57 however, while such fibrillar artificial silks are relatively robust compared to other biological materials and promise a novel range of properties in composite applications, 38,44 their mechanical properties still fall short of their natural silk counterparts. 9,38,40,43,44,54,57 The diminished capability of RSF to self-assemble is in line with past studies that have revealed deviations in the structure and bonding character of the RSF molecule.…”

Preparation of regenerated silk fibroin/silk sericin fibers by coaxial electrospinning

“…Recently, the electrospinning process has been developed to prepare SF-based biomaterials with a submicron diameter. In most of prior studies about the electrospinning of SF solution, the SF spinning dopes were also formed by using organic solvents [11][12][13][14], or further blending with poly (ethylene oxide), chitosan, collagen and other synthetic or nature polymers [15][16][17]. Only few researches were implemented using water as solvent and pure SF aqueous solution as spinning dope [18][19][20].…”

A novel method to prepare tussah/Bombyx mori silk fibroin-based films

“…[15][16][17] The as-cast BSF and TSF lms are water soluble due to their random coil structure, post-treatment using organic solvents is required, such as methanol, ethanol. 18,19 To develop highly biocompatible silk broin material, using less toxic solvents is an important direction.…”