title: Preparation, stability and cytocompatibility of magnetic/PLA-PEG hybrids.
abstract: Hybrid nanocolloids based on biodegradable polymers of poly(lactide) (PLA) or poly(lactide)-block-poly(ethylene glycol) (PLA-PEG) and hydrophobic iron oxide magnetic nanoparticles (MNPs) of ca. 5 nm are prepared via a self-assembly route. The magnetic nanoparticles are organized in superclusters inside the hydrophobic core of PLA-PEG micelles or cholate-stabilized PLA nanospheres. The hydrodynamic diameter of MNPs-loaded PLA nanospheres is approximately 250 nm, whereas that of MNPs-loaded PLA-PEG micelles is much lower (approximately 100 nm) and thus compatible with applications where prolonged blood circulation is required. The PLA-PEG micelles exhibit high encapsulation efficiency for the MNPs, imparting a saturation magnetization value to the hybrid of 8.4 emu g(-1). Both hybrid colloids display magnetic properties of a non-interacting assembly of superparamagnetic particles and a low blocking temperature, both of which are key attributes for colloidally stable ferrofluids. Furthermore, the PLA-PEG magnetic hybrids display remarkable colloidal stability at high ionic strength, temperature and in human blood plasma, while the estimated critical micelle concentration of ca. 2 x 10(-5) mM (0.3 mg L(-1)) indicates the low probability of the colloids dissociation in the blood compartment. They were also found to be non-toxic to human cells in vitro. The results underline the potential of the magnetic/PLA-PEG hybrids and encourage further research for their in vivo biomedical applications.
authors.affiliation: Materials Science Department, School of Natural Sciences, University of Patras, Rio 26504, Patras, Greece.
authors.forename: Aristides
authors.initials: A
authors.lastname: Bakandritsos
authors.forename: George
authors.initials: G
authors.lastname: Mattheolabakis
authors.forename: Radek
authors.initials: R
authors.lastname: Zboril
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Bouropoulos
authors.forename: Jiri
authors.initials: J
authors.lastname: Tucek
authors.forename: Dimitrios G
authors.initials: DG
authors.lastname: Fatouros
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Avgoustakis
mesh_terms: D006801:Humans; D007501:Iron / Q000737:chemistry; D007773:Lactates / Q000737:chemistry*; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry; D008823:Micelles; D009994:Osmolar Concentration; D010087:Oxides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D013696:Temperature
chemical_list: D007773:Lactates; D008823:Micelles; D010087:Oxides; C088513:poly(lactic acid-ethylene glycol); D011092:Polyethylene Glycols; D007501:Iron