title: 1H NMR spectroscopy as a tool for determining the composition of poly(hydroxyethyl-L-asparagine)-coated liposomes.
abstract: Liposomes coated with the poly(amino acid) poly(hydroxyethyl-L-asparagine) (PHEA) show long-circulation properties comparable to the frequently used PEG-liposomes. The pharmacokinetic characteristics of long-circulating liposomes are dependent on the density of the shielding polymer on the liposome surface. Therefore, it is necessary to know the exact composition of the liposomes including the amount of coating polymer present on the liposome surface. In this study, a 1H NMR method to establish the composition of liposomes coated with PHEA was developed and validated.
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands.
authors.forename: Birgit
authors.initials: B
authors.lastname: Romberg
authors.forename: J Jantina
authors.initials: JJ
authors.lastname: Kettenes-van den Bosch
authors.forename: Tom
authors.initials: T
authors.lastname: de Vringer
authors.forename: Gert
authors.initials: G
authors.lastname: Storm
authors.forename: Wim E
authors.initials: WE
authors.lastname: Hennink
mesh_terms: D001216:Asparagine / Q000031:analogs & derivatives* / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015394:Molecular Structure; D011522:Protons; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D008055:Lipids; D008081:Liposomes; D011522:Protons; C511917:poly(hydroxyethyl-L-asparagine); D001216:Asparagine