Liposomes for drug delivery - Surface modifications & screening for compositions at the edge of stability
Date issued
Authors
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
License
Abstract
First, increasing amounts and molecular weights of liposome surface modifications as poly-(ethylene) glycol (PEG) or hyperbranched polyglycerol (hbPG) resulted in an overall decrease of liposome diameter and a qualitative increase in blood circulation times in vivo. The cellular uptake of hbPG modified liposomes by macrophages was considerably higher in vitro and in vivo than of PEGylated liposomes independently from the protein corona.
Second, liposomes ‘at the edge’ of stability were desired and systematically screened for by incorporation of laurdan as membrane stability indicator. Identified lipid compositions were optimized for storage stability using cholesteryl hemisuccinate and complied a moderately high drug release under late endosomal conditions while for the most part retaining their drug upon storage. In vitro and in vivo experiments confirmed increased release capability of identified liposomes in comparison to conventional liposomes, even upon modification of candidate liposomes with pH-sensitive ketal- or vinylether-PEG.