Orientational behaviors of silk fibroin hydrogels

Abstract

In this study, a novel shear‐induced silk fibroin (SF) hydrogel with three‐dimensional (3D) anisotropic and oriented gel skeleton/network morphology is presented. Amphipathic anionic and nontoxic sodium surfactin is blended with the SF to decrease its gelation time during the mechanical shearing process. The fibroin/surfactin blended solutions undergo a facial shearing process to accomplish a sol–gel transition within 1 hour. The dynamic sol–gel transition kinetic analysis, gel skeleton/network morphology, and mechanical property measurements are determined in order to visualize the fibroin/surfactin sol–gel transition during the shearing process and its resulting hydrogel. The results demonstrate that there is significant β‐sheet assembly from random coil conformations in the fibroin/surfactin blended system during the facile shearing process. The SF β‐sheets further transform into a fibrous large‐scale aggregation with orientational and parallel arrangements to the shearing direction. The shear‐induced fibroin/surfactin hydrogel exhibits notable anisotropic and oriented 3D skeleton/network morphology and a significant mechanical compressive strength in proportion to the shearing stress, compared with the control fibroin/surfactin hydrogel undergoing no shearing process. Due to its oriented gel skeleton/network structure and significantly enhanced mechanical properties, the shear‐induced fibroin/surfactin gel may be suitable as a biomaterial in 3D oriented tissue regeneration, including for nerves, the cultivation of bone cells, and the repair of defects in muscle and ligament tissues. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45050.

Bioactive silk hydrogels with tunable mechanical properties

“…Although multiple cues such as stiffness, compositions and nanostructures have significant influence on cell proliferation, the cell culture results on RSF-SNF hydrogels indicated that the introduction of SNF resulted in a better niche for cell response in vitro , which is similar to several studies that revealed an enhanced influence of nanofibrous SF materials on cell compatibility. 28,47–49…”

Tunable High-Molecular-Weight Silk Fibroin Polypeptide Materials: Fabrication and Self-Assembly Mechanism

“…Dynamic molecular conformation of HSF samples (5 mg/mL) at 50 °C was measured using a circular dichroism (CD) spectrometer (JASCO, Japan). − After incubation at 50 °C, the samples were added into a quartz cuvette with a thickness of 0.1 mm, and the ultraviolet polarizing spectrum was scanned in the wavelength range of 190–250 nm. The measurement temperature was 25 °C, the broadband was 1.00 nm, the wavelength step was 0.20 nm, and the response time was 0.33 s. The CD of deionized water was also determined under the same experimental conditions, and the value was subtracted from the final result.…”

3D Printable Hydrogel Bioelectronic Interfaces for Healthcare Monitoring and Disease Diagnosis: Materials, Design Strategies, and Applications

“…Owing to the unique temperature-dependent gelation properties, gelatin, and GelMA are widely used for 3D printing applications. For GelMA, by introducing and regulating photoinitiators and employing light exposure (such as UV light, blue light, or white light), the methacrylamide and methacrylate [100][101][102] Copyright 2018, Wiley-VCH; Copyright 2018, American Chemical Society; Copyright 2018, Wiley-VCH. d) Fabrication of graphene/silk fibroin-based conductive hydrogels under electric field stimulation.…”