Liposomes evolved into lipid vesicles that are lipid membrane artificial cells

Bangham first reported the preparation of liposomes each consisting of microspheres of hundreds of concentric lipid bilayers — multi-lamellar (Fig. 11.4) (Bangham et al., 1965). They used these as a membrane model for basic membrane research. Back in the 1960s, I encouraged a

Polylactide artificial cells containing insulin

Polylactide artificial cells containing insulin

Very slow release

TIME (HRS)

Fig. 11.10. Biodegradable membrane artificial cells have been prepared to contain enzymes, hormones, vaccines, and other biologicals (Chang, 1976a). This figure summarizes the result of polylactide artificial cells prepared using the double emulsion method (Appendix II). Variations in the molecular weight of polylactide and thickness of the membrane can result in artificial cells that release insulin at different rates. Faster release occurs during encapsulation of insulin solution at high concentration, while very slow release occurs during encapsulation of insulin crystals. (Chang, 1976a).

newly graduated McGill Ph.D., Gregoriadis, to look into different ways of forming artificial cells for the delivery of biologics. His subsequent research in England resulted in the first report on the use of liposomes as drug delivery systems that has opened a whole new approach (see 1976 book edited by Gregoriadis). The large amount of lipid in the original multi-lamellar liposome limits the amount of water soluble drugs that can be enclosed. Thus, the basic principle and method of preparing artificial cells using ether as the dispersing phase (Chang 1957, 1964) was extended by researchers into what they called an "ether evaporation method" to form single bilayer (unilamellar) lipid membrane liposomes (Deamer DW and Bangham AD, 1976). These lipid membrane artificial cells, i.e. lipid vesicles, have since been extensively studied for use as drug delivery systems (Torchilin, 2005).

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