Toxicological evaluation and targeting tumor cells through folic acid modified guar gum nanoparticles of curcumin

Abstract

The investigation was aimed for designing pH-sensitive, polymeric surface modified Guar Gum Nanoparticles (GgNP) with Folic acid (FA) loaded with curcumin (CU), a natural anti-cancer agent, for the treatment of colon cancer with the objective to enhance the bioavailability of CU, concurrently reducing the required dose through selective targeting to colon. The CU loaded FA functionalized GgNP (CU-FA-GgNP) has been prepared by emulsion cross linking method. These surface modified nanoparticles were compared with unmodified CU loaded GgNP (CU-GgNP). Various process parameters were optimized and the optimized formulation was evaluated for particle size distribution, % drug entrapment and in vitro drug release in simulated gastrointestinal fluids (SGIF). IR spectroscopy confirms the successful modification of CU-FA-GgNP and TEM confirms the surface morphology. Anti-cancer potential of the formulation was demonstrated by MTT assay in Caco-2 cells line. The average size of CU-FA-GgNP was found to be 245 nm in diameter having polydispersity index (PDI) 0.165 indicating mono-disperse particles. The zeta potential of the particles was found to be - 38.1 mV. The CU-FA-GgNP protects the release of CU in upper gastrointestinal tract while maximum release of CU occurred in simulated colonic fluids of pH 6.8. The nanoparticles (NP) were found to be non-toxic at the dose equivalent to 2000 mg/kg of body weight of CU in the acute-toxicity study. Sub-acute-toxicity study proved the safety of the formulation for prolonged administration at the commonly used therapeutic dose of 100 mg/kg of body weight of CU. These studies provide evidences that CU-FA-GgNP holds promise to address colorectal cancer over-expressing folate receptors and they were found to be safe for oral administration for a short as well as a prolonged duration.