Effects of tremella-alginate-liposome encapsulation on oral delivery of inactivated H5N3 vaccine

In this study, we evaluated a system for oral vaccine delivery, consisting of liposomes coated first with a layer of tremella and then with an outer layer of acid-induced alginate. In vitro release studies showed that the triple layer of alginatetremellaliposomes was more resistant to an acidic pH and modulated the release profiles at an alkaline pH. Transepithelial electrical resistance (TEER) studies revealed that liposomes or tremella-coated liposomes were able to open tight junctions of the Caco-2 cell monolayer. In mice, although serum immunoglobulin G (IgG) was not expected to increase and haemagglutination inhibition showed that antibody levels were still too low to provide sufficient protection, alginatetremellaliposomes encapsulated virus-induced intestinal secretory immunoglobulin A (s-IgA) production to provide protection against virus infection. In conclusion, an oral virus vaccine entrapped in alginatetremellaliposomes improved the mucosal antiviral s-IgA response. This system may have potential use as a carrier for oral vaccine delivery.