Modelling of drug encapsulation using vesicles

Abstract

Aggregates of surface-active molecules consisting of one or more bilayers arranged in a hollow, closed, usually spherical geometry are termed ‘‘vesicles’’. The objective of this study was modelling of drug encapsulation using vesicles. We have investigated the distribution of cytochrome-C protein in both SOS/CTAB and DMPC/DMPG systems at different concentrations. The results were observed spectrophotometrically. Cytochrome-C containing vesicles were isolated from the protein in the bulk by ultrafiltration of vesicle samples through 30, 100, and 300 kDa filters. Two different types of filters were used in ultrafiltration experiments. Ultrafiltration of samples was repeated for 10 times. Ultrafiltration of SOS/CTAB containing cytochrome-C was unsuccessful because vesicle aggregation was observed during the ultrafiltration. DMPC/DMPG vesicles were also prepared with cholesterol in their bilayers. Ultrafiltration of DMPC/DMPG/protein with/without cholesterol could not be carried on with filter having polyethersulfone (PES) membrane but satisfactory results were obtained from the one with regenerated cellulose (RC) membrane. Breakdown of DMPC/DMPG vesicles containing cytochrome-C after ultrafiltration process was done with the addition of bile salt, sodium cholate. After the breakdown, it was observed that there was no protein released, suggesting that no protein was trapped in the DMPC/DMPG vesicles without cholesterol. On the other hand, a considerable cytochrome-C signal was observed from the disintegrated DMPC/DMPG vesicles with cholesterol, suggesting that protein encapsulation was successful.