The mean diameters measured from approximately 100 randomly selected particles from each group were found to be 24.2 ± 3.6, 20.0 ± 3.6, 15.8 ± 3.6, and 10.5 ± 2.4 nm for groups A, B, C, and D, respectively. As the rotational speed

increased, the MNP diameters decreased, with significant differences between Selleck SN-38 adjacent groups (P < 0.01). The hydrodynamic diameter distributions of the MNPs in the four groups were Gaussian-like, with values of 65.5 ± 14.0, 38.9 ± 9.1, 23.1 ± 6.0, and 18.5 ± 4.4 nm (Figure 2a) and volume ratios of 29%, 48%, 13%, and 10% for groups A to D, respectively. Further, from the measured volume ratios in Figure 2a, the highest MNP volume was observed for group B; groups C and D could also provide an adequate quantity of

uniform-sized MNPs for use in applications that require very small sized (approximately 10 nm) MNPs. The amount www.selleckchem.com/products/eft-508.html of synthesized MNPs from group D was approximately 0.5 g, which could be easily scaled-up using a larger reaction vessel. Figure 1 TEM images of the four MNP groups. The TEM images show that the particles were well dispersed and size-regulated according to the group. The mean diameters for the four groups were 24.2 ± 3.6, 20.0 ± 3.6, 15.8 ± 3.6, and 10.5 ± 2.4 nm, for groups a to d, respectively. Figure 2 Relative size distributions of separated MNP groups and correlation between DLS and TEM results. Selleck A-769662 Relative size distributions of separated MNP groups in aqueous solution measured by DLS (a) and a graph showing correlation between DLS and TEM results (b). The mean DLS diameters for the four groups, A to D, were 65.5 ± 14.0, 38.9 ± 9.1, 23.1 ± 6.0, and 18.5 ± 4.4 nm, respectively, with relative volumes of 29% (A), 49% (B),

12% (C), and 10% (D) as measured by integration of the DLS spectra. The mean diameter of the MNPs, as measured by TEM and DLS, decreased selleck kinase inhibitor as the centrifugation speed decreased (Figure 2b), indicating that the MNP particles synthesized by the coprecipitation method were well separated and clearly resolved into the four groups by the different centrifugation speeds. Using the organometallic method reported by others, the particle size of MNPs can be easily controlled, with a narrower diameter distribution achievable in comparison to the combined coprecipitation and centrifugation methods described here. However, the amount of MNPs that can be synthesized in a single process is quite small, and these have the added disadvantage of being hydrophobic. A coating is therefore necessary in order to render these MNPs hydrophilic and to enable them to be used for functions such as drug loading, targeting, or imaging probes (PET or fluorescence). Even though the size distribution of MNPs synthesized by the coprecipitation method was large, huge amounts of size-controlled MNPs were obtained by combining the method with a simple centrifugation process.