POLYMERIZED LIPOSOMES AS POTENTIAL ORAL VACCINE CARRIERS - STABILITY AND BIOAVAILABILITY

The potential of polymerized liposomes as oral vaccine carriers is eva luated. The stability of polymerized liposomes is demonstrated in mous e gastrointestinal tracts using dual-labeled liposomes. Similar transi t kinetics displayed by the two labels of different hydrophobicity ind icate the intactness of the polymerized liposomes inside the gastroint estinal tract. Uptake of liposomes from mouse gastrointestinal tract b y Peyer's patches is quantified by measuring the amount of radiolabele d liposomes retained in the tissues following liposome oral administra tion. Bioavailability of liposomal contents is examined in macrophage cultures with calcein-containing liposomes. Liberation of calcein in c ells suggests the breakdown of liposomal membranes and the intracellul ar release of their encapsulated materials.