Delivery of Grouper Interferon by Chitosan-Modified Poly(lactic-co-glycolic acid) Nanoparticles to Protect Nervous Necrosis Virus Infection

Abstract

The outbreaks of viral disease including nervous necrosis virus (NNV) have become major problems in aquaculture and cause massive mortalities of grouper larvae, leading to enormous economic losses for farms and hatcheries. Interferons (IFNs) are potent antiviral cytokines that enhance a grouper larva innate immune system by triggering various antiviral proteins. In this study, we utilized ultra-sonication to nano-encapsulate grouper IFN (gIFN) using chitosan modified poly(lactic-co-glycolic acid) (PLGA) as a carrier. Sample obtained was expressed as PLGA-gIFN NP expecting to protect IFN from the damage in a fish gastrointestinal tract. The results showed that nanoparticles (NPs) loaded with gIFN were monodisperse with sizes ranged around 150 nm and successfully achieved an acceptable encapsulation efficiency of 65.5%. Particles were stable during storage with an initial burst release in the first 4 h and shown a low cumulative release rate only of 18% which limited an anti-NNV effect of IFN in the animal test. However, with a dosage increasing from 0.05 to 0.1 mu g of PLGA-gIFN/fish in oral administration, the relative percent survival (RPS) increased by 12.38 to 46.67, that seemed to be better in an increasing rate compare to the non-encapsulated one (RPS rose to 60.59 from 34.07). It is deduced that this nano-encapsulation technique could protect IFNs from damage in a fish gastrointestinal tract and performed its functionality when been uptaken into cells. Since NPs are able to approach easily using sonication, the less cytotoxic PLGAg-IFN NPs could be produced commercially as a reliable and promising aquaculture pharmaceutical product for disease prevention and treatment in fish fries.