Alcohol‐triggered silk fibroin hydrogels having random coil and β‐turn structures enhanced for cytocompatible cell response

Abstract

Alcohol additive is one of the stimulants that induces the fast gelation of silk fibroin solution. Based on our previous report, different alcohol types influence the gelation kinetic and the properties of resulting silk fibroin hydrogels. Here, the effects of alcohol concentrations on the silk fibroin gelation and cell response were reported. All fibroin hydrogels prepared with various alcohol additives showed cell biocompatibility, especially the fibroin hydrogel prepared with 10 wt % n‐butanol. Results on the mechanical properties of hydrogels, n‐butanol additive enhanced a higher compressive modulus up to ~ 22 times in comparison to non‐alcoholic fibroin hydrogel. Fourier transform infrared analysis and peak deconvolution showed a possible formation of more β‐turn linkage and random coil structure of fibroin segments in alcoholic fibroin hydrogel. So, the micro‐segmental structure of fibroin hydrogel caused the higher compressive modulus, prolonged deformation of the hydrogels, and efficient cell growth on the fibroin hydrogel. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48731.

A study on source dependent batch to batch variations in silk fibroin films for potential applications in corneal tissue engineering

“…Subsequent MTT assays showed about 100% cell viability in the test samples (KL, TN, and TS). The ISO 10993‐5 standard was previously explored for determining the cytotoxicity of silk biomaterials in various forms (hydrogels, 26,27 films, 5 nanofibrous mat, 28 etc. ), wherein the cell viability was found to be greater than 70%—which was the acceptable limit as per the said standard.…”

Silk fibroin hydrogels for biomedical applications

“…Notably, different alcohols show diverse induction effects on fibroin gelation. Alcohols containing longer fatty segments, such as n‐butanol, induce ß ‐sheet formation in a milder manner 60 . Although with rapid and easy processing, solvents' presence is one of the factors limiting cell applications (especially in situ cell encapsulation).…”

“…To accelerate the physical gelation process, alcohols can usually be introduced to induce the ß-sheet formation in silk fibroin hydrogels. [60][61][62][63][64] The polarity of the solvent plays a significant role during the gelation process of silk fibroin using the mechanism that the polar reagents use to capture water molecules from the silk molecular chains, resulting in the formation of ß-sheet nucleation sites. 53 Notably, different alcohols show diverse induction effects on fibroin gelation.…”

Self-assembled silk fibroin hydrogels: from preparation to biomedical applications

“…In Table propanediol, and glycerol) on the SF gelation at 25 °C (Figure 5a). 84 They used 5 wt % fibroin solutions, and the alcohol content of the solutions was fixed at 10 wt %. The gelation of the system was monitored by optical density analysis.…”

“…In their another study, Kaewprasit et al prepared a series of SF hydrogels via alcohol-induced self-assembly. 85 Methanol, butanol, and glycerol were used as triggers to induce self-assembly. They conducted cell attachment and proliferation tests with L929 cell lines on hydrogels produced with different alcohol types.…”