Bohdana M. Discher

TL;DR: The results suggest a new class of synthetic thin-shelled capsules based on block copolymer chemistry, and both the membrane bending and area expansion moduli of electroformed polymersomes (polymer-based liposomes) fell within the range of lipid membrane measurements.

TL;DR: The stealthiness introduced to liposomes through PEGylation is extended here with completely synthetic polymersomes, which are vesicles composed entirely of PEG-based block copolymer amphiphiles that are not only more proportionately designed, but also have already been shown to considerably broaden the range of vesicle properties.

Abstract: Vesicles made completely from diblock copoly- mers—polymersomes—can be stably prepared by a wide range of techniques common to liposomes. Pro- cesses such as film rehydration, sonication, and ex- trusion can generate many-micron giants as well as monodisperse, ~100 nm vesicles of PEO-PEE (polyethyl- eneoxide-polyethylethylene) or PEO-PBD (polyethyl- eneoxide-polybutadiene). These thick-walled vesicles of polymer can encapsulate macromolecules just as lipo- somes can but, unlike many pure liposome systems, these polymersomes exhibit no in-surface thermal tran- sitions and a subpopulation even survive autoclaving. Suspension in blood plasma has no immediate ill-effect on vesicle stability, and neither adhesion nor stimulation of phagocytes are apparent when giant polymersomes are held in direct, protracted contact. Proliferating cells, in addition, are unaffected when cultured for an ex- tended time with an excess of polymersomes. The ef- fects are consistent with the steric stabilization that PEG-lipid can impart to liposomes, but the present single-component polymersomes are far more stable mechanically and are not limited by PEG-driven micell- ization. The results potentiate a broad new class of tech- nologically useful, polymer-based vesicles. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 135-145, 2001.

TL;DR: A diblock copolymer of poly(ethylene oxide)-polybutadiene that has a hydrophilic weight fraction like that of lipids and forms robust fluid phase membranes in water and implies defect-free membranes many microns-squared in area is described.

TL;DR: In this paper, it was shown that the universal thickness of 3-4 nm, which is well known for natural lipid vesicles, reflects no physical limitation on the amphiphilic assembly at the nano-scale.