Electrospinning Device: Stretchable hydrogels

Background

Silk fibroin (SF) extracted from silkworms has unique properties, including biodegradability, biocompatibility, and ease of processing. Hydrogels derived from SF are attractive soft materials for biomedical applications, such as drug delivery and tissue engineering. They are usually prepared by inducing β-sheet formation in aqueous SF solutions via several triggering factors, such as SF concentration, solvent quality, pH, temperature, cations, vortices, electric fields, or by chemical cross-linking reactions of natural or chemically modified SF. However, the SF hydrogels reported so far are usually brittle when stretched, limiting their load-bearing applications.

Study on the improvement of mechanical properties of silk fibroin hydrogels

Introduction of PDMAA to enhance mechanical properties: Flexible poly(N,N-dimethylacrylamide) (PDMAA) was synthesized in situ by adding N,N-dimethylacrylamide (DMAA) monomer and ammonium persulfate (APS) initiator to an aqueous solution of silk fibroin (SF) containing 1,4-butanediol diglycidyl ether (BDDE) and N,N,N'-tetramethylethylenediamine (TEMED). PDMAA chains interconnect spherical SF molecules through their vinyl side groups to form an interconnected SF/PDMAA network, thereby enhancing the mechanical properties of SF hydrogels.

Adjusting the β-sheet content: The mechanical properties of SF hydrogels can be adjusted by adjusting the amount of polymethyl methacrylate incorporated to adjust the β-sheet content in the SF network. The higher the pH of the reaction system, the lower the β-sheet content and the lower the modulus G'. By controlling the β-sheet content, the mechanical properties of SF hydrogels can be optimized to show better toughness and ductility when stretched.

Application of electrospinning equipment in the preparation of silk fibroin hydrogels

Preparation of nanofiber structures: Electrospinning equipment can prepare silk fibroin nanofibers with specific structures and properties. These nanofibers can be used to construct finer hydrogel structures and further optimize their mechanical properties. For example, silk fibroin nanofibers prepared by electrospinning technology can be compounded with PDMAA to form composite materials with better mechanical properties and biocompatibility.

Regulating the microstructure of hydrogels: Electrospinning technology can precisely control the diameter and morphology of nanofibers by adjusting parameters such as the concentration, viscosity, and electric field strength of the spinning solution. This allows the pore structure and pore size of silk fibroin hydrogels to be precisely regulated, thereby better meeting the requirements of mechanical properties and biocompatibility.

Loading bioactive substances: Electrospinning equipment can prepare nanofiber hydrogels loaded with bioactive molecules. For example, growth factors and drugs that promote tissue repair are loaded into silk fibroin nanofibers, and the release rate is controlled to achieve the continuous effect of bioactive substances in the hydrogel. This can not only enhance the biological function of the hydrogel, but also further improve its effect in biomedical applications.

Summary

In summary, the improvement of the mechanical properties of silk fibroin hydrogels makes it possible for them to achieve a wider range of applications, and electrospinning equipment provides strong technical support for their preparation. Through electrospinning technology, nanofiber hydrogels with specific structures and properties can be prepared, and the mechanical properties and biocompatibility of silk fibroin hydrogels can be further optimized, thereby improving their application effects in the biomedical field.

Electrospinning Nanofibers Article Source:

https://doi.org/10.1016/j.ijbiomac.2020.08.040