From encapsulation efficiency to molecular motion rate: A detailed characterization of magnetoliposomes.

This paper describes a detailed characterization of simple magnetoliposomes (MLPs), in relation to the design, production and economic accessibility of magnetic-triggered antitumoral systems. It focuses on the effect of maghemite nanoparticles (Fe2O3 NPs) on the lipidic parameters of MLPs. Magnetometry studies have shown that the saturation magnetization of MLPs was around 16% lower than the one related to Fe2O3 NPs. Dynamic light scattering (DLS) analyses demonstrated that the size variation of MLPs, stored between 20 and 50 days, corresponded to half of the one related to liposomes. ζ-potential values higher than -30 mV were obtained in this period. Small angle X-ray spectroscopy (SAXS) indicated that the presence of Fe2O3 NPs preserved the number, spacing and thickness of the lipid bilayers. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC) data indicated that Fe2O3 NPs restrict the lipid motions of MLPs. Correlations between the structural events, lipid motion, and stability of MLPs were found and performed.