Therapeutic effects of methotrexate encapsulated in hyaluronic acid-coated exosomes derived from Wharton's jelly mesenchymal stem cells in a rat model of rheumatoid arthritis.

BACKGROUND

Methotrexate (MTX) is widely used for treating rheumatoid arthritis (RA); however, its clinical application is limited because of its nonspecific distribution and significant long-term adverse effects. We developed a hyaluronic acid (HA)-modified exosome (Exo) encapsulating MTX to enhance therapeutic efficacy in a rat RA model.

METHODS

Exosomes were isolated from Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) and loaded with MTX, then coated with HA. Exo/MTX/HA characterized using UV-visible spectrophotometry, and Fourier transform infrared (FTIR) spectroscopy. Encapsulation efficiency, in vitro drug release, and cytotoxicity were assessed. Serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-17 (IL-17), transforming growth factor-beta (TGF-β), aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), C-reactive protein (CRP), and rheumatoid factor (RF) were measured by ELISA and commercial kits. Gene expression of T-bet, GATA3, Foxp3, RORγt, matrix metalloproteinases (MMPs), lincRNA-p21, and MALAT1 was quantified by real-time PCR.

RESULTS

The Exo/MTX/HA treatment group showed significantly decreased serum levels of TNF-α, IL-17, CRP, and RF but increased TGF-β levels (p < 0.001). Furthermore, Exo/MTX/HA significantly downregulated T-bet, RORγt, MALAT1, MMP-9, and MMP-13, and upregulated Foxp3, GATA3, and LncRNA-p21 expression (p < 0.001). Hematoxylin and Eosin (H&E) staining revealed that, compared with the other treatments, Exo/MTX/HA markedly reduced joint cell infiltration (p < 0.01). Safety assessments showed no hepatotoxicity in the Exo/MTX/HA, Exo/MTX, or Exo/HA groups compared to the MTX group.

CONCLUSION

This study presents a method to improve the therapeutic effect of methotrexate against rheumatoid arthritis using the Exo/MTX/HA.