Folate-conjugated hydrophobicity modified glycol chitosan nanoparticles for targeted delivery of methotrexate in rheumatoid arthritis

Background: Targeted delivery to the Rheumatoid arthritis (RA) which is characterized by destruction and degeneration of bones due to chronic inflammation is of great need. RA being a chronic autoimmune disorder might result in severe disability and morbidity. A targeted delivery system is designed to deliver methotrexate (MTX) for RA. Methods: Here, we synthesized folic acid (FA) conjugated hydrophobically modified glycol chitosan (GC) self-assembled nanoparticles (FA-GC-SA) for the targeted delivery of MTX to RA. The FA conjugation and hydrophobic modification of GC by stearic acid (SA) was confirmed by Fourier-transform infrared spectroscopy (FTIR). The FA-GC-SA was exploited for developing targeted nanoparticles encapsulating MTX by the ionic gelation method. The particles were characterized and evaluated for their targeting potential in in vitro cell culture studies. Further their in vivo efficacy in arthritis induced rats using collagen was also evaluated. Results: FTIR confirms the successful modification of GC-SA and FA-GC-SA. The FA-GC-SA-MTX of size 153 +/- 9 nm were prepared with high encapsulation efficiency of MTX. The FA-GC-SA-MTX size was further confirmed by transmission electron microscopy (TEM). In vitro cell studies revealed the superior efficacy of FA-GC-SA-MTX in cell cytotoxicity. Also, significantly higher cellular uptake of FA functionalized FA-GC-SA-MTX was observed in comparison to non-functionalized GC-SA-MTX attributed to folate receptors (FRs) mediated endocytosis. In vivo results confirms the potential of FA-GC-SA-MTX which reduces reduces the pro-inflammatory cytokines, paw thickness, and arthritis score in collagen induced rats. Conclusion: The results shows that FRs targeted FA-GC-SA-MTX has superior efficacy in the treatment of RA.