Sterilization on Dextran-Coated Iron Oxide Nanoparticles: Effects of Filtration, Autoclaving, and Ethanol Treatment

Abstract

Dextran-coated iron oxide magnetic nanoparticles (DMNPs) have attracted significant attention for their applications in biomedical area. For this purpose, DMNPs must be sterile, and several terminal sterilization methods can be used. However, very little is known regarding the effect of sterilization methods on the properties of DMNPs. We studied the influences of autoclaving on DMNPs colloids and investigated the effects of sterile filtration and chemical sterilization with ethanol by using TEM, UV-Vis spectroscopy, FT-IR spectroscopy, DLS, VSM, and in vitro cytotoxicity study. Our results indicate caution must be taken on the sterilization methods for DMNPs. Filter sterilization reduced the amount of DMNPs significantly. Autoclaving affected the physical properties of DMNPs, increasing their hydrodynamic sizes dramatically, and decreasing their saturation magnetization. The ethanol sterilization did not exhibit any effect on the DMNPs and it is more suitable to sterilize DMNPs.