Nanostructured lipid carrier mediates effective delivery of methotrexate to induce apoptosis of rheumatoid arthritis via NF-κB and FOXO1.

Present study was designed to develop novel nano-structured lipid carriers (NLCs) formulated by lipid mixture and chemical permeation enhancer-based hydrogel for an effective transdermal delivery of methotrexate (MTX). The prepared NLCs were optimized with different preparative variables such as particle size <200 nm, poly-dispersity index (PDI) <0.2, and entrapment efficiency ∼85%. The drug incorporated into NLCs-gel base showed excellent spread ability without any grittiness during rheological behavior and texture profile analysis. The in vitro release showed biphasic release pattern with initial fast release of drug (>50%) in 8h followed by sustained release (up to 85%) by the end of 48thh. NLCs showed greater uptake in human hyper-proliferative keratinocyte cell line (HaCaT). NLCs showed increased expression of inflammatory mediators as well asapoptosis in U937 monocytic cells. The greater expression of pro-apoptotic gene Bim regulated by NF-κB-IkB and FOXO1 is supported by fold regulations calculated for various apoptotic and pro-inflammatory biomarkers carried out by RT-PCR. The immunocytochemistry to detect IL-6 expression and immunofluorescence assay suggested that induced apoptosis occurs in experimentally induced in vitro arthritis model treated with NLCs-MTX. We saw reduced inflammation and triggered apoptosis through NF-κB & FOXO1 pathways induced by MTX loaded NLCs in rheumatoid arthritic cells. In addition, formulated NLCs exhibit better skin permeation with higher permeation flux & enhancement ratio as shown by confocal laser scanning microscopy (CLSM). Moreover, histopathological examinations of skin are suggestive of safety potential of NLCs.