Oral administration of colitis tissue-accumulating porous nanoparticles for ulcerative colitis therapy

To improve the penetration and accumulation of anti-inflammatory drugs in colitis tissue, we functionalized the surface of porous poly(lactic-co-glycolic acid) nanoparticles (NPs) using pluronic F127 (PF127) and loaded curcumin (CUR) into the resulting NPs to obtain porous PF127-functionalized CUR-loaded NPs (porous PF127-NPs). These NPs had an average hydrodynamic diameter of about 270 nm with a highly monodisperse size distribution, slightly negative surface charge and controllable CUR release profile. It was found that they had good biocompatibility and yielded a much higher cellular uptake rate of CUR than porous CUR-loaded NPs without PF127 modification (porous NPs). In addition, porous PF127-NPs showed a greater capacity to inhibit the major pro-inflammatory cytokines (IL-6, IL-12 and TNF-α) secreted from lipopolysaccharide-activated macrophages than porous NPs and non-porous PF127-NPs. In vivo experiments suggested that porous PF127-NPs achieved the best therapeutic outcomes against ulcerative colitis (UC) in mice compared with porous NPs and non-porous PF127-NPs. Our results clearly demonstrate that these fabricated porous PF127-NPs show a great promise as an efficient CUR nanocarrier for UC therapy.