title: A novel method for the encapsulation of biomolecules into polymersomes via direct hydration.
abstract: One of the major engineering challenges for the implementation of block copolymer vesicles, or polymersomes, as therapeutic drug carriers is obtaining high encapsulation efficiencies for biomolecules. Here we present a novel method for encapsulation of proteins with high encapsulation efficiency within polymersomes formed from block copolymers of poly(ethylene glycol)-bl-poly(propylene sulfide). By formulation of the neat block copolymer with a low molecular weight poly(ethylene glycol), direct hydration of the formulated mixture yielded polymersomes. We were able to achieve encapsulation efficiencies for ovalbumin at 37%, bovine serum albumin at 19%, and bovine gamma-globulin at 15% when the proteins were included in the hydration solution. The formulation process and the dispersion of polymersomes from the preparation in phosphate-buffered saline were characterized using confocal microscopy, cryogenic transmission electron microscopy, and fluorimetry. We were also successful in the encapsulation of proteinase K, a proteolytic enzyme, and demonstrated by SDS-PAGE that the enzyme was contained inside polymersomes when dispersed in a solution of ovalbumin.
authors.affiliation: Institute for Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 15, CH-1015 Lausanne, Switzerland.
authors.forename: Conlin P
authors.initials: CP
authors.lastname: O'Neil
authors.forename: Tomoake
authors.initials: T
authors.lastname: Suzuki
authors.forename: Davide
authors.initials: D
authors.lastname: Demurtas
authors.forename: Andrija
authors.initials: A
authors.lastname: Finka
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Hubbell
mesh_terms: D000818:Animals; D002214:Capsules / Q000737:chemistry*; D002417:Cattle; D018613:Microscopy, Confocal; D049329:Nanostructures / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D002214:Capsules; D011108:Polymers; D014867:Water; D012710:Serum Albumin, Bovine