Chitosan–Alginate Microcapsules for Oral Delivery of Egg Yolk Immunoglobulin (IgY): Effects of Chitosan Concentration

Abstract

In our previous study, chitosan-alginate microcapsules were developed to protect egg yolk immunoglobulin (IgY) from gastric inactivation. The present study was undertaken to determine the effect of chitosan concentration (0-0.8%; w/v) on various properties of the microcapsules in order to produce the optimum chitosan-alginate microcapsules for use in the oral delivery of IgY. The properties investigated included microcapsule morphology, loading capacity for IgY (expressed as the IgY loading percentage, w/w, of microcapsules), encapsulation efficiency (EE%), in vitro gastroresistance, and IgY release. IgY loading percentage and EE% were both highest at 0.2% (w/v) chitosan, and, above this level, further increases were not observed. The stability of IgY in simulated gastric fluid (pH 1.2) was significantly improved by encapsulation in alginate microcapsules (IgY retained 43.5% of its activity) and was further improved by including chitosan at any of the chitosan concentrations assessed (IgY retained an average of 69.4% activity) although there was no difference in protection of gastric inactivation among concentrations of chitosan varying from 0.05% to 0.8% (w/v). Higher chitosan concentrations (i.e., >/=0.2%; w/v) prolonged the release of IgY from the microcapsules during simulated intestinal fluid incubation (pH 6.8). However, above the 0.2% (w/v) level, no significant differences were observed. We conclude that the optimum chitosan concentration for microencapsulation is 0.2% (w/v).

Nano Functional Food: Opportunities, Development, and Future Perspectives

“…The principle is to evenly disperse the core material in the wall material solution and then add another substance or solvent to condense the wall material mixture and form microcapsules around the core material [110]. Li et al successfully used sodium alginate and chitosan to microencapsulate yolk immunoglobulin and found that sodium alginate/chitosan microcapsules can effectively protect yolk immunoglobulin from the killing effect of gastric juice [111]. The phase separation method is a very effective microencapsulation technology with a relatively simple process, and the embedding rate is 85%~90%.…”

Egg Yolk Antibodies for Passive Immunity

“…The macroencapsulation of IgY using enteric-coated gelatin capsules has also been examined and was found to significantly improve antibody stability (Akita & Nakai 2000). The use of a pH-sensitive methacrylic acid copolymer (Kovacs-Nolan & Mine 2005), chitosan-alginate microcapsules (Li et al 2007(Li et al , 2009a, and whey protein-based microcapsules (Cho et al 2005) have also been shown to increase IgY stability to gastric conditions, both in vitro and in vivo. Recently, Xun et al (2010) described the use of the cytoprotective agent sucralfate and found that it could improve IgY resistance to low pH and pepsin treatment, as well as enhance storage stability, in a dose-dependent manner.…”

Chitosan-based polyelectrolyte complexes as pharmaceutical excipients

“…In a more recent report, the same team showed that an initial chitosan solution of 0.2% (w/v) resulted in maximal microcapsules production efficiency, IgY protection against SGF for at least 2 h, and effective release of IgY in SIF (Li et al, 2009c). The encapsulation of IgY by chitosan-alginate significantly improved the stability of IgY compared with encapsulation by alginate (69% of IgY activity vs. 44%).…”

“…This complexation reduces the porosity of alginate particles and prevents the fast release of formulated drugs (Murata et al, 1993;Polk et al, 1994;Sezer and Akbuga, 1999). In this case, the calcium ions, because of their low molecular weight, diffuse more rapidly than chitosan into the alginate core to form a gel core (Li et al, 2009c). The first procedure is a one-step method whereby the alginate solution is dropped into a chitosan solution containing calcium chloride.…”