Authors: L.I. Privalova, B.A. Katsnelson, S.V. Kuzmin, T.D. Degtyareva, M.P. Sutunkova, O.S. Yeremenko, M.Y. Khodos, A.N. Kositsina, N.A. Malakhova, J.A. Glazyrina
Affilation: Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Russian Federation
Pages: 550 - 552
Keywords: magnetite nanoparticles, cytotoxicity, alveolar macrophages, neutrophil leukocytes
It is often maintained that nanoparticles are poorly recognized by host’s defence mechanisms and, specifically, cause weak attraction of phagocytes and are therefore removed from lungs ineffectively. However, intratracheal instillation of water-suspended magnetite nanoparticles caused a higher increase in alveolar macrophages (AM) and neutrophil leukocytes (NL) count of bronchoalveolar lavage fluid (BALF) than instillation of microparticles of the same substance. Judging by NL/AM ratio, cytotoxicity of 10 nm particles for AM is higher than that of 50 nm particles, while they both are much more cytotoxic than 1 um particles. Both AMs and NLs were more « loaded» with visible particles in BALF of lungs instilled with 10 nm magnetite as compared with those instilled with 50 nm one, while nanoparticles of both sizes were engulfed much more avidly than microparticles. In a separate comparative experiment it was demonstrated that magnetite nanoparticles are more cytotoxic as compared with titanium dioxide and quartz suspensions having particle size distribution typical of workroom dusts. Cosidered all, we believe that the concept of quasi-defenselessness of organism against nanoparticles should be critically re-evaluated. In the same time, our results confirm that nanoparticles of a substance can be indeed more biologically aggressive than their micrometric counterpart.