title: Evaluation of multifunctional liposomes in human blood serum by light scattering.
abstract: To overcome the limited functionality of "stealth" lipids based on linear poly(ethylene glycol) (PEG) chains, hyperbranched polyether-based lipids that bear multiple hydroxyl groups for further chemical modification may be a suitable replacement. This study focuses on the development and characterization of "stealth" liposomes modified with a novel hyperbranched polyglycerol lipid (cholesterol-PEG30-hbPG23). An emphasis was placed on the stability of these liposomes in comparison to those containing a linear PEG derivative (cholesterol-PEG44) directly in human blood serum, characterized via dynamic light scattering (DLS). Polymer lipid contents were varied between 0 and 30 mol %, resulting in liposomes with sizes between 150 and 80 nm in radius, depending on the composition. DLS analysis showed no aggregation inducing interactions between serum components and liposomes containing 10-30 mol % of the hyperbranched lipid. In contrast, liposomes functionalized with comparable amounts of linear PEG exhibited aggregate formation in the size range of 170-330 nm under similar conditions. In addition to DLS, cryo-transmission electron microscopy (TEM) was employed for all liposome samples to prove the formation of unilamellar vesicles. These results demonstrate the outstanding potential of the introduction of hyperbranched polyglycerol into liposomes to stabilize the assemblies against aggregation while providing additional functionalization sites.
authors.affiliation: Institute of Physical Chemistry, Johannes Gutenberg University Mainz , Welderweg 11, 55128 Mainz, Germany.
authors.forename: Kristin
authors.initials: K
authors.lastname: Mohr
authors.forename: Sophie S
authors.initials: SS
authors.lastname: Müller
authors.forename: Laura K
authors.initials: LK
authors.lastname: Müller
authors.forename: Kristiane
authors.initials: K
authors.lastname: Rusitzka
authors.forename: Sabine
authors.initials: S
authors.lastname: Gietzen
authors.forename: Holger
authors.initials: H
authors.lastname: Frey
authors.forename: Manfred
authors.initials: M
authors.lastname: Schmidt
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D002784:Cholesterol / Q000737:chemistry; D005990:Glycerol / Q000737:chemistry*; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes / Q000097:blood* / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*
chemical_list: D008055:Lipids; D008081:Liposomes; D011108:Polymers; C043941:polyglycerol; D002784:Cholesterol; D005990:Glycerol