Journal Article

An Injectable Enzymatically Crosslinked and Mechanically Tunable Silk Fibroin/Chondroitin Sulfate Chondro‐Inductive Hydrogel

Redl, Heinz, Mirzadeh, Hamid, Herbert Teuschl, Anderaes, Farokhi, Maryam, Solouk, Atefeh

2023

Overview

An injectable hybrid hydrogel is synthesized, comprising silk fibroin (SF) and chondroitin sulfate (CS) through di‐tyrosine formation bond of SF chains. CS and SF are reported with excellent biocompatibility as tissue engineering scaffolds. Nonetheless, the rapid degradation rate of pure CS scaffolds presents a challenge to effectively recreate articular cartilage. As CS is one of the cartilage extracellular matrix (ECM) components, it has the potential to enhance the biological activity of SF‐based hydrogel in terms of cartilage repair. Therefore, altering the CS concentrations (i.e., 0 wt%, 0.25 wt%, 0.5 wt%, 1 wt%, and 2 wt%), which are interpenetrated between SF β‐sheets and chains, can potentially adjust the physical, chemical, and mechanical features of these hybrid hydrogels. The formation of β‐sheets by 30 days of immersion in de‐ionized (DI) water can improve the compression strength of the SF/CS hybrid hydrogels in comparison with the same SF/CS hybrid hydrogels in the dried state. Biological investigation and observation depicts proper cell attachment, proliferation and cell viability for C28/I2 cells. Gene expression of sex‐determining region YBox 9 (SOX9), Collagen II α1, and Aggrecan (AGG) exhibits positive C3H10T1/2 growth and expression of cartilage‐specific genes in the 0.25 wt% and 0.5 wt% SF/CS hydrogels. In the current study, an injectable hybrid hydrogel containing silk fibroin (SF) and chondroitin sulfate (CS) is prepared and characterized through di‐tyrosine formation bonds between SF chains using horse radish peroxide (HRP) and hydrogen peroxide (H2O2). In fact, altering CS amounts, which are interpenetrated between SF β‐sheets and chains adjusts the physical, chemical, and biological features of these hybrid hydrogels.

• Publisher: John Wiley & Sons, Inc,Wiley-VCH
• Subject: Aggrecan / Biocompatibility / Biological activity / Cartilage / Cartilage (articular) / Cell adhesion / Cell proliferation / Cell viability / Chains / Chondroitin sulfate / Collagen (type II) / compression strength / Compressive strength / enzymatic crosslinking / Extracellular matrix / Gene expression / Hydrogels / injectable hydrogels / Scaffolds / Sheets / Silk / Silk fibroin / Sox9 protein / Tissue engineering / Tyrosine