Preparation of liposomes containing protein extract form Pasteurella multocida

Abstract

Liposomes containing protein extract from Pasteurella multocida prepared by double emulsion technique were studied on the effect of molar ratio of egg yolk lecithin to cholesterol on their physiconchemical properties and stability. The molar ratio of egg yolk lecithin to cholesterol used were 1:0, 7:2, and 1:1. The particle size and entrapping efficiency depended on the cholesterol content, 1:1 molar ratio of lecithin to cholesterol liposomes which was cholesterol rich liposomes gave the large particle sizes (5.92 µm) and high entrapping efficiency (45.26+1.25%). Moreover, the higher cholesterol content gave a more stability of liposomes. In this study, CM-Cellulose and CM-Chitosan in concentration of 0.02%, 0.2% and 0.5% w/v were used to stabilize liposomes. The physicochemical properties and stability of polymer coated liposomes were investigated. These polymers form mesh like layer around liposome vesicles. They do not disturb the structure of bilayer and entrapping efficiency. The more increasing concentrations of polymers, the stability of liposomes was increased in PBS pH 7.4 at 37℃. The percent of released protein from 0.5% w/v carboxymethylchitosan coated liposomes were reduced about 60% within 10 hours (from 99.05% to 33.02%). The polymer coated liposomes were kept in the closed seal containers, they could remain the protein content over 90% at 4℃ for 3 months.