Effects of magnetic cobalt ferrite nanoparticles on biological and artificial lipid membranes

Abstract

Barbara Drašler,1 Damjana Drobne,1–3 Sara Novak,1 Janez Valant,1 Sabina Boljte,1,4 Lado Otrin,1 Michael Rappolt,5,6 Barbara Sartori,5 Aleš Iglic,7 Veronika Kralj-Iglic,8 Vid Šuštar,9 Darko Makovec,3,10 Sašo Gyergyek,10 Matej Hocevar,11 Matjaž Godec,11 Jernej Zupanc11University of Ljubljana, Biotechnical Faculty, Department of Biology, Ljubljana, 2Centre of Excellence in Advanced Materials and Technologies for the Future, Ljubljana, 3Centre of Excellence in Nanoscience and Nanotechnology, Ljubljana, 4Institute of Microbial Sciences and Technologies, Ljubljana, Slovenia; 5Institute of Inorganic Chemistry, Graz University of Technology, Basovizza, Italy; 6School of Food Science and Nutrition, University of Leeds, Leeds, UK; 7Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, 8Faculty of Health Sciences, Laboratory of Clinical Biophysics, University of Ljubljana, Ljubljana 9Laboratory of Clinical Biophysics, Chair of Orthopaedics, Faculty of Medicine, University of Ljubljana, Ljubljana, 10Institute Jožef Stefan, Ljubljana, 11Institute of Metals and Technology, Ljubljana, SloveniaBackground: The purpose of this work is to provide experimental evidence on the interactions of suspended nanoparticles with artificial or biological membranes and to assess the possibility of suspended nanoparticles interacting with the lipid component of biological membranes.Methods: 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid vesicles and human red blood cells were incubated in suspensions of magnetic bare cobalt ferrite (CoFe2O4) or citric acid (CA)-adsorbed CoFe2O4 nanoparticles dispersed in phosphate-buffered saline and glucose solution. The stability of POPC giant unilamellar vesicles after incubation in the tested nanoparticle suspensions was assessed by phase-contrast light microscopy and analyzed with computer-aided imaging. Structural changes in the POPC multilamellar vesicles were assessed by small angle X-ray scattering, and the shape transformation of red blood cells after incubation in tested suspensions of nanoparticles was observed using scanning electron microscopy and sedimentation, agglutination, and hemolysis assays.Results: Artificial lipid membranes were disturbed more by CA-adsorbed CoFe2O4 nanoparticle suspensions than by bare CoFe2O4 nanoparticle suspensions. CA-adsorbed CoFe2O4-CA nanoparticles caused more significant shape transformation in red blood cells than bare CoFe2O4 nanoparticles.Conclusion: Consistent with their smaller sized agglomerates, CA-adsorbed CoFe2O4 nanoparticles demonstrate more pronounced effects on artificial and biological membranes. Larger agglomerates of nanoparticles were confirmed to be reactive against lipid membranes and thus not acceptable for use with red blood cells. This finding is significant with respect to the efficient and safe application of nanoparticles as medicinal agents.Keywords: CoFe2O4, nanoparticles, agglomerates, human red blood cells, lipid vesicles