Keywords: Drug delivery; DSPE-PEG; PEG-ylated liposomes; Monolayers
Due to the growing importance of controlled drug delivery systems (DDS), the main task of nanotechnology is to develop stable, effective and non-toxic nanocarriers in which the drug can be encapsulated and delivered to a specific diseased site in the patient's body. Currently, one of the most popular ways to improve the pharmacokinetic and physicochemical properties of liposomes is introducing into their structure poly(ethylene glycol) chains conjugated with 1,2-disteroil-sn-glycero-3-phosphoethanolamine (DSPE) molecules. Because the research so far does not give an unequivocal answer which length of PEG chains is more beneficial for liposomes properties, the aim of this work was to investigate the influence of this parameter (DSPE-PEG350, DSPE-PEG750 and DSPE-PEG2000) on model DPPC membrane. The studies were performed on monolayer and bilayer systems and were related to the surface pressure measurements, Brewster angle microscopy experiments, Grazing Incidence X-ray Diffraction studies, dynamic light scattering and zeta potential measurements and the experiments with the calcein release and steady-state fluorescence anisotropy of DPH. The obtained results proved that the molecular organization of the DPPC membrane strongly depends on the length of poly(ethylene glycol) chains conjugated with DSPE. Moreover, the addition of different lengths of polymer chains changes the properties of formulated liposomes, especially their stability, permeability, size and surface charge. (C) 2021 The Authors. Published by Elsevier B.V.
