Drug targeting to arthritic region via folic acid appended surface-engineered multi-walled carbon nanotubes.

This study was aimed at developing and investigating folate anchored carbon nanotubes for targeting an anti-arthritic drug, Methotrexate (MTX) to inflammatory arthritic region. The folic acid (FA) was conjugated to amidated multi-walled carbon nanotubes (MWCNTs) and confirmed by Fourier transform infrared (FTIR), (1)H NMR spectroscopy and X-ray diffraction analysis. The MTX was loaded into the pristine and functionalized-MWCNTs and extensively characterized in vitro and in vivo studies. The drug entrapment efficiency was found high in folate conjugated MWCNTs. In vitro drug release in PBS (pH 7.4) from pristine MWCNTs and folate conjugated MWCNTs formulation was found to be 66.35 ± 2.3 and 56.88 ± 1.9% in 24 h, respectively. Folate conjugated MWCNTs significantly increased (p < 0.005) the percentage inhibition of arthritis, biological half-life and volume of distribution of MTX as compared to MTX-loaded naked MWCNTs as well as free MTX. In in vivo biodistribution studies, MTX was found to be significantly higher (p < 0.005) in arthritic joints from folate functionalized MWCNTs as compared to free drug as well as drug-loaded naked MWCNTs. The present outcomes highlights the propensity of drug-loaded functionalized MWCNTs to alter the pharmacokinetics as well as sustained and targeted drug delivery system as well.