Polymersomes: Tough Vesicles Made from Diblock Copolymers

• Published in: Science (American Association for the Advancement of Science) Vol. 284; no. 5417; pp. 1143 - 1146
• Main Authors: Discher, Bohdana M., Won, You-Yeon, Ege, David S., James C-M. Lee, Bates, Frank S., Discher, Dennis E., Hammer, Daniel A.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 14.05.1999; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Applied sciences; Aspiration; Block copolymers; Cell membranes; Chemical Phenomena; Chemistry, Physical; Copolymers; Electrodes; Exact sciences and technology; Lipid bilayers; Lipid Bilayers - chemistry; Lipids; Liposomes; Membranes; Membranes, Artificial; Molecular chains; Molecular Weight; Molecules; Organic Chemistry; Organic polymers; Osmotic Pressure; P branes; Permeability; Phospholipids; Phospholipids - chemistry; Physicochemistry of polymers; Polyethylenes - chemistry; Polymers; Polymers - chemistry; Properties and characterization; Solution and gel properties; Surface Tension; Water; Vesicle; Molecular assembly; Morphology; Diblock copolymer; Mechanical properties; Butadiene derivative copolymer; Aqueous solution; Ethylene oxide copolymer; Experimental study; Amphiphilic polymer
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.284.5417.1143

Vesicles were made from amphiphilic diblock copolymers and characterized by micromanipulation. The average molecular weight of the specific polymer studied, polyethyleneoxide-polyethylethylene (EO$_{40}$-EE$_{37}$), is several times greater than that of typical phospholipids in natural membranes. Both the membrane bending and area expansion moduli of electroformed polymersomes (polymer-based liposomes) fell within the range of lipid membrane measurements, but the giant polymersomes proved to be almost an order of magnitude tougher and sustained far greater areal strain before rupture. The polymersome membrane was also at least 10 times less permeable to water than common phospholipid bilayers. The results suggest a new class of synthetic thin-shelled capsules based on block copolymer chemistry.