A comparison between plain eugenol and eugenol-loaded chitosan nanoparticles for prevention of in vitro selenite-induced cataractogenesis

The purpose of this work was to improve the antioxidant and anticataractogenic potential of eugenol by encapsulating it within chitosan nanoparticles via an emulsion–ionic gelation crosslinking method. Various ratios of chitosan to eugenol (1:0.75, 1:1 and 1:1.25) were optimized by encapsulation efficiency, loading capacity, drug-releasing profile, and in-vitro antioxidant potential. Synthesized eugenol-loaded chitosan nanoparticles (ECNP 1:1) and plain chitosan nanoparticles (CNPs) were characterized by UV–visible spectrometry, dynamic light scattering (DLS), X-ray powder diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and atomic force microscopy (AFM). The range of sizes of ECNPs, as determined by the AFM and DLS methods, was approximately 200–600 nm. 3–4,5-(dimethyl-thyazol-2-yl)-2,5-diphenyltetrazolium (MTT) analysis revealed that ≥ 50% of cultured human lenticular epithelial (HLE-B3) cells remained viable when exposed to an ECNP concentration of 150 μM or less. These ECNPs were evaluated for efficacy in preventing experimental in-vitro selenite-induced cataractogenesis. Encapsulation of eugenol within chitosan nanoparticles appeared to improve the antioxidant capacity of plain eugenol; this could conceivably improve the anticataractogenic potential of eugenol.