Nanoparticles as a novel delivery system for vitamin C administration in aquaculture

Abstract

Abstract The potential of chitosan-based nanoencapsulation as a tool for delivering ascorbic acid (AA) to marine and freshwater organisms was investigated. Polymeric non-loaded and loaded vitamin C nanoparticles (NPs) were made by ionic gelation and the particles were characterized. In vitro performance of nanoparticles was evaluated in a zebrafish liver cell-line (ZFL) and in vivo studies were carried out in fish (post-metamorphic larvae of Solea senegalensis) and rotifers (Brachionus plicatilis) to assess the potential use of these NPs to be used as a tool in nutritional aquaculture studies. The results showed that NPs are suitable to trap hydrosoluble compounds such as AA by forming positively charged complexes (30–35 mV), in a nanosize range ( 90% of loaded AA remained within nanoparticles after 2 h in seawater). The potential cytotoxicity of the NPs was evaluated in ZFL cells and no decrease in cell viability was noted up to 2.5 mg/ml of nanoparticle concentration. The NP uptake was analyzed in ZFL cells by FACS cytometry and confocal laser scanning microscopy (CLSM). Time course and dose–response experiments were performed using fluorescein isothiocyanate labeled NPs (FITC-NPs). The in vitro endocytosis assays with ZFL cells showed a maximum uptake after 6 h of incubation and a dose-dependent increase of fluorescence intensity directly proportional to the FITC-NP concentration. The antioxidant properties of vitamin C nanoparticles (AA-NPs) were also analyzed in ZFL cell extracts. Lipopolysaccharide (LPS) was added to ZFL cells to induce oxidative stress. The total antioxidant capacity of the AA-NP-treated cells showed a statistically significant increase with respect to the control with non-loaded nanoparticles (71.00 ± 9.6 and 25.36 ± 3.96 μM Trolox equivalent; p