Ocular delivery of cyanidin-3-glycoside in liposomes and its prevention of selenite-induced oxidative stress

Context: Cataracts have become the leading cause of blindness around the world, which is mainly mediated by oxidative stress.Objective: N-trimethyl chitosan (TMC)-coated liposomes of cyanidin-3-glycoside (C3G) (C3G-TCL) were prepared to attenuate oxidative stress induced by selenite sodium in rats.Materials and methods: C3G-TCL were prepared by reverse-phase evaporation method and then coated with self-synthesized TMC. The physicochemical properties were determined. A gamma-scintigraphy study was employed to evaluate the precorneal elimination of the radioactive preparations. The transcorneal visualization for fluorescence-labeled samples was determined by confocal laser scanning microscopy (CLSM). The in vivo anti-oxidative study using C3G-TCL was carried out in rats with selenite-induced cataracts by topical administration.Results: The sphere-like morphological characterization of the vesicles was confirmed by TEM, with a size of 158.32.8nm and a zeta potential of 31.7mV. The encapsulation efficiency was (53.7 +/- 0.2) % as measured by ultrafiltration. C3G-TCL showed a 3.3-fold increment in precorneal residence time when compared with that of the Tc-99m-solution. A TMC coating enhanced the transepithelial transport of liposomes to a depth of 40-m in the cornea. Moreover, C3G-TCL could significantly elevate the activity of superoxide dismutase and catalase in lens and also show a considerable reversal of reduced glutathione activity. The lipid peroxidation in lens was strongly prevented when compared with that of groups treated with uncoated C3G-loaded liposomes.Discussion and conclusion: The coating material TMC for liposomes helps improve the anti-oxidative effect of C3G in vivo through prolonged residence time on the cornea and improved permeability in the corneal epithelium.