B. mori silk fibroin (SF) protein is a biopolymer naturally synthesized and spun into a microfiber by the Bombyx mori silkworms. It is composed of a (GAGAGS)n backbone, that tend to self-assemble into nanofibrillar structural organization, similarly to $\beta$-sheet rich amyloid assembly, under the action of shear forces, particularly elongational flow. Due to the intrinsic characteristics of fibroin protein in its soluble state as well as a spun fiber, such as biocompatibility, biodegradability and low cytotoxicity [1], and combined with its natural mechanical properties of high tensile strength and flexibility, this substrate is of particular interest for materials for tissue engineering and regeneration applications [2]. Such usage has been registered in different forms, including films, hydrogels, scaffolds etc [3].

With a complex charge distribution on its monomers, electric fields can induce fibril orientation and even alter chain bonding. Therefore, in this work, we investigate the effect of electric fields (EF) in the context of being used as a tool for controlled self-assembly of SF proteins and films. SF was produced by the standard degumming method [4].

Preliminary results show a difference in $\beta$-sheet content regarding samples produced with an electric field from the control untreated samples, with a higher effect on more concentrated films. Furthermore, AFM analysis show an indication of fiber orientation in the EF films. SEM and AFM images of SF solutions deposited on glass clearly shows an orientation regarding the AC EF application.

References
[1] X.-L. Lin, L.-L. Gao, R.-X. Li, W. Cheng, C.-Q. Zhang, X.-Z. Zhang Materials Science and Engineering: C, 2019, 105, 110018.
[2] G. Li, S. Sun Molecules, 2022, 27(9), 2757.
[3] A. Solomonov, A. Kozell, U. Shimanovich Angewandte Chemie International Edition, 2024, e202318365.
[4] D. N. Rockwood, R.C. Preda, T. Yucel, X. Wang, M.L. Lovett, D.L. Kaplan Nature Protocols, 2011, 6, 1612-1631.