Sea-Island Micelle Structured Hydrogel Scaffold: A Dual-Action Approach to Combat Cartilage Damage under RA Conditions

Rheumatoid arthritis (RA) is a common autoimmune joint disease characterized by persistent synovial inflammation and cartilage damage. The current clinical treatments primarily utilize drugs such as triptolide (TP) to address inflammation, yet they are unable to directly repair damaged cartilage. Furthermore, the persistent inflammation often undermines the effectiveness of traditional cartilage repair strategies, preventing them from achieving optimal outcomes. To tackle this challenge, this study successfully developed a drug-loaded polyurethane hydrogel-oriented porous scaffold, designed to address persistent inflammation and facilitate cartilage repair under RA conditions. A drug-loaded hydrogel was formed via solvent-induced polyurethane-gelatin, resulting in the scaffold TP@GSPU. The sea-island micelle structure of TP@GSPU enables efficient loading of TP. The release of TP in the in vivo environment regulates the expression of inflammatory factors in macrophages, thereby improving the inflammatory microenvironment within the joint cavity. Additionally, the gelatin component of the scaffold provides robust support for cartilage regeneration. The efficacy of the TP@GSPU in regulating the inflammatory microenvironment and facilitating cartilage repair under RA conditions, which was demonstrated through cartilage damage repair experiments conducted in a rat collagen-induced arthritis (CIA) model. The design scheme of this material offers a potential approach to cartilage repair in the conditions of RA.