Preparation of magnetoliposomes with a green, low-cost, fast and scalable methodology and activity study against S. Aureus and C. Freundii bacterial strains

Abstract

A novel, fast, low-cost and scalable methodology to prepare stable magnetoliposomes (MGLs), without the use of organic solvents, is described. The concept of the work is based on the dual use of soy lecithin associated to a new liposome preparation methodology. Soy lecithin was used to coat the nanoparticles of magnetite (Fe3O4@lecithin) and for encapsulation of Fe3O4@lecithin (Lip-Fe3O4@lecithin). Liposomes with size less than 160 nm, polydispersity index of 0.25 and zeta potential of -41 mV, were prepared with the use of autoclave and sonication. The liposomal formulations containing magnetite and stigmasterol (Lip-Fe3O4@lecithin, Lip-Stigma and Lip-Stigma-Fe3O4@lecithin) were shown to be promising for the application as antibacterial. The liposomal formulation and magnetite were characterized by the following techniques: conventional and high-resolution transmission electron microscopy (TEM/HRTEM), energy-filtered transmission electron microscopy (EFTEM), proton nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), dynamic light scattering (DLS) and zeta potential. The Lip-Fe3O4@lecithin had a minimum inhibitory concentration (MIC) of 8.4 μg mL-1 in the presence of 200 Oe magnetic field against S. aureus.