Preparation of Liposomal Microcapsules by Proliposome Method with Soybean Lecithin

Liposomal encapsulation was carried out with soybean and egg yolk lecithins. Bovine serum albumin (BSA) was encapsulated by proliposome and dehydration-rehydration (DR) method. Highest encapsulation efficiency (41.9%) was achieved by prolipsome method with soybean lecithin. Encapsulation eficiency of BSA by proliposome-capsules was determined under the pH of 3,5 and 7. Degradation of the capsules was observed at pH 3 and BSA was released from the capsules. To stabilize proloposome-capsules under acidic conoditions, ethanol-soluble fraction of soybean lecithin was used to prepare the capsules. The capsules showed high stablity at pH3 and encapsulated BSA was retained 74.5% after incubation at 37℃ for 2h. In addition, the prolisome-capsules with ethanol-soluble fraction of soybean lecithin exhibited high resistance against the simulated gastric solution (pH 1.2), while the capsules were readily degrated by Hofmann bile salt solution. These results suggest that the prolisome-capsules would be useful for targeted delivery of function food ingredients acted in the intestial tract

Liposomal Microcapsulation of Enzymes by Proliposome Method with Chitosan-Coating

Liposomal microcapsulation containing enzymes were prepared by proliposome method to improve a stability of enzymes under acidic conditions. Two model enzymes, β-galactosidase and alkaline phosphatase, were encapsulated by a method with soybean lecithin (β-galactosidase; 57.3%, alkaline phosphatase; 53.0%) . However, the microcupsules did not exhibit the stabilizing effect for β-galactosidase at pH 3. Chitosan-coating was made for proloposome-capsules to keep enzymatic activity under acidic conditions. The mictocupsules coated with >0.5% of chitosan 10 showed high stability at pH3, and encapsulated β-galactosidase was retained 80.7% of its activity. Similarly, alkaline phosphatase was highly stabilized by the encapsulation with chitosan-coating at pH5 for 60min, while uncapsulated one lost 53.3% of its activity. The activity of encapsulated alkaline phosphatase was kept 20.1 and 59.2% for 60 min at pH3 and 4, respectively, while uncapsulated alkaline phosphatase was completely inactivated at these pHs