EFFECT OF COBALT FERRITE MAGNETIC NANOPARTICLES IN HYDROPHILIC COATING ON THE CONDUCTIVITY OF BILAYER LIPID MEMBRANES

Abstract

Magnetic nanoparticles are widely used in medical applications, for example, as contrast agents for magnetic resonance imaging, to enhance hyperthermia, for targeted drug delivery, theranostics (therapy + diagnostics). When used in vivo, magnetic nanoparticles require a special coating that promotes biocompatibility and minimizes potential toxicity under physiological conditions. Human serum albumin or polyethylene glycol can be used as a coating. In this work, the interactions of magnetic cobalt ferrite nanoparticles (12 and 27 nm size) with diphitanoylphosphatidylcholine bilayer lipid membranes were investigated. The conductivity of membranes varied over a wide range – two groups of membranes can be distinguished – membranes, the conductivity of which (after the addition of nanoparticles) remained practically unchanged compared to the control, and membranes, the conductivity of which, upon the addition of nanoparticles, changed abruptly and increased in a wide range by 0.5–2 orders of magnitude. Significant differences between the conductivities upon the addition of the same volume of 12 and 27 nm nanoparticles surrounded by human serum albumin were not found. When adding nanoparticles with a coating of polyethylene glycol, the conductivity increased much weaker than when adding nanoparticles with a coating of human serum albumin. The results suggest that hydrophilic coated magnetic nanoparticles interact with the membranes, which can lead to the appearance of metastable conducting pores, which, in turn, increase the integral conductivity of the membranes.