Alginate Microencapsulation for Oral Immunisation

Authors: Bikramjit Ghosh Barbara F Nowak Andrew R Bridle

Publish Date: 2015/09/26

Volume: 17, Issue: 6, Pages: 841-853

PDF Link

Abstract

This study examined the feasibility of alginate microcapsules manufactured using a lowimpact technology and reagents to protect orally delivered immunogens for use as immunoprophylactics for fish Physical characteristics and protein release kinetics of the microcapsules were examined at different pH and temperature levels using a microencapsulated model protein bovine serum albumin BSA Impact of the microencapsulation process on contents was determined by analysing change in bioactivity of microencapsulated lysozyme Feasibility of the method for oral immunoprophylaxis of finfish was assessed using FITClabelled microcapsules These were applied to distal intestinal explants of Atlantic salmon Salmo salar to investigate uptake ex vivo Systemic distribution of microcapsules was investigated by oral administration of FITClabelled microcapsules to Atlantic salmon fry by incorporating into feed The microcapsules produced were structurally robust and retained surface integrity with a modal size distribution of 250–750 nm and a tendency to aggregate Entrapment efficiency of microencapsulation was 512  for BSA and 432  in the case of lysozyme Microcapsules demonstrated controlled release of protein which increased with increasing pH or temperature and the process had no significant negative effect on bioactivity of lysozyme Uptake of fluorescentlabelled microcapsules was clearly demonstrated by intestinal explants over a 24h period Evidence of microcapsules was found in the intestine spleen kidney and liver of fry following oral administration Amenability of the microcapsules to intestinal uptake and distribution reinforced the strong potential for use of this microencapsulation method in oral immunoprophylaxis of finfish using sensitive immunogenic substances

Keywords: