Incorporation of ovalbumin into ISCOMs and related colloidal particles prepared by the lipid film hydration method

TY - JOUR

T1 - Incorporation of ovalbumin into ISCOMs and related colloidal particles prepared by the lipid film hydration method

AU - Demana, Patrick H

AU - Davies, Nigel M

AU - Berger, Bianca

AU - Rades, Thomas

PY - 2004/7/8

Y1 - 2004/7/8

N2 - The aim of this study was to investigate the incorporation of a model antigen, fluorescently labelled ovalbumin (FITC-OVA), into various colloidal particles including immune stimulating complexes (ISCOMs), liposomes, ring and worm-like micelles, lamellae and lipidic/layered structures that are formed from various combinations of the triterpene saponin Quil A, cholesterol and phosphatidylethanolamine (PE) following hydration of PE/cholesterol lipid films with aqueous solutions of Quil A. Colloidal dispersions of these three components were also prepared by the dialysis method for comparison. FITC-OVA was conjugated with palmitic acid (P) and PE to produce P-FITC-OVA and PE-FITC-OVA, respectively. Both P-FITC-OVA and PE-FITC-OVA could be incorporated in all colloidal structures whereas FITC-OVA was incorporated only into liposomes. The incorporation of PE-FITC-OVA into all colloidal structures was significantly higher than P-FITC-OVA (P <0.05). The degree of incorporation of protein was in the order: ring and worm-like micelles <liposomes and lipidic/layered structures <ISCOMs and lamellae. The incorporation of protein into the various particles prepared by the lipid film hydration method was similar to those for colloidal particles prepared by the dialysis method (provided both methods lead to the formation of the same colloidal structures). In the case of different colloidal structures arising due to the preparation method, differences in encapsulation efficiency were found (P <0.05) for formulations with the same polar lipid composition. This study demonstrates that the various colloidal particles formed as a result of hydrating PE/cholesterol lipid films with different amounts of Quil A are capable of incorporating antigen, provided it is amphipathic. Some of these colloidal particles may be used as effective vaccine delivery systems.

AB - The aim of this study was to investigate the incorporation of a model antigen, fluorescently labelled ovalbumin (FITC-OVA), into various colloidal particles including immune stimulating complexes (ISCOMs), liposomes, ring and worm-like micelles, lamellae and lipidic/layered structures that are formed from various combinations of the triterpene saponin Quil A, cholesterol and phosphatidylethanolamine (PE) following hydration of PE/cholesterol lipid films with aqueous solutions of Quil A. Colloidal dispersions of these three components were also prepared by the dialysis method for comparison. FITC-OVA was conjugated with palmitic acid (P) and PE to produce P-FITC-OVA and PE-FITC-OVA, respectively. Both P-FITC-OVA and PE-FITC-OVA could be incorporated in all colloidal structures whereas FITC-OVA was incorporated only into liposomes. The incorporation of PE-FITC-OVA into all colloidal structures was significantly higher than P-FITC-OVA (P <0.05). The degree of incorporation of protein was in the order: ring and worm-like micelles <liposomes and lipidic/layered structures <ISCOMs and lamellae. The incorporation of protein into the various particles prepared by the lipid film hydration method was similar to those for colloidal particles prepared by the dialysis method (provided both methods lead to the formation of the same colloidal structures). In the case of different colloidal structures arising due to the preparation method, differences in encapsulation efficiency were found (P <0.05) for formulations with the same polar lipid composition. This study demonstrates that the various colloidal particles formed as a result of hydrating PE/cholesterol lipid films with different amounts of Quil A are capable of incorporating antigen, provided it is amphipathic. Some of these colloidal particles may be used as effective vaccine delivery systems.

KW - Cholesterol

KW - Colloids

KW - Drug Delivery Systems

KW - Fluorescein-5-isothiocyanate

KW - Fluorescent Dyes

KW - ISCOMs

KW - Ovalbumin

KW - Phosphatidylethanolamines

KW - Saponins

KW - Technology, Pharmaceutical

U2 - 10.1016/j.ijpharm.2004.03.021

DO - 10.1016/j.ijpharm.2004.03.021

M3 - Journal article

C2 - 15196631

SN - 0378-5173

VL - 278

SP - 263

EP - 274

JO - International Journal of Pharmaceutics

JF - International Journal of Pharmaceutics

IS - 2

ER -