Trimethylamine N-oxide (TMAO)-grafted silicone hydrogels for anti-fibrosis

Abstract

The foreign body reaction (FBR) induced by the host immune system leads to fibrous encapsulation, which significantly impairs the functionality of implanted medical devices and can trigger complications. Zwitterionic polymers derived from trimethylamine N-oxide (TMAO) demonstrate particularly remarkable hydrophilicity and antifouling capabilities due to the direct connection between their positive and negative charges. In this study, based on the unique molecular structure of TMAO, a polysiloxane with TMAO and carbon–carbon double bonds as side chains was designed and synthesized. Subsequently, under the combined action of a photoinitiator and ultraviolet (UV) irradiation, a hydrogel with a Si–O–Si backbone was fabricated. In vitro tests demonstrated that the trimethylamine N-oxide-grafted silicone (TMAO-Si) hydrogel exhibits excellent resistance to protein adsorption and cell adhesion, while also exhibiting good biocompatibility. Building on these findings, we implanted the hydrogel in mice. The results indicated a significant reduction in the adhesion of inflammatory cells to the surface of the TMAO-Si hydrogel, with collagen fiber deposition thickness markedly lower than that observed in PEG hydrogels, thereby demonstrating superior anti-fibrotic encapsulation effects. Consequently, the TMAO-Si hydrogel shows promising potential as an implant material that minimizes interference from FBRs, offering a new technical approach for the development of long-lasting in vivo implant materials.