Various methods have been employed to synthesize SPIONs with controllable size, such as controlled co-precipitation of GSI-IX in vitro Fe(II) and Fe(III) ions at an elevated temperature [17], successive reduction-oxidation process in a reverse micelle system [18], thermal decomposition [19], and a hydrothermal method under higher pressures [20].

To make SPIONs with good water dispersity and desired surface functionality for biomedical applications, surfactant molecules [21, 22], silane agents [23–25] or other small molecular ligands [9, 26–28], polyethylene glycol (PEG) derivatives [29, 30], and dendrimers [15, 31, 32] have been used to modify SPIONs using either in situ modifications or post-modification approaches. In our previous work, we adopted

a simple one-step 3-aminopropyltrimethoxysilane (APTS)-assisted hydrothermal approach to synthesize click here APTS-coated Fe3O4 NPs with reactive surface amine groups [33]. The APTS modification endowed Fe3O4 NPs with an excellent water dispersibility and colloidal stability. Additionally, these APTS-coated Fe3O4 NPs can be further functionalized with acetyl groups with neutral surface potential following the reaction of the surface APTS amines with acetic anhydride. Our results suggest that the presence of APTS molecules not only enables efficient APTS coating of the particles with reactive amine groups but also significantly limits the particle growth. This prior success led us to hypothesize that acetylated APTS-coated Fe3O4 NPs may serve as a labeling

agent for MR imaging of cancer cells both in www.selleckchem.com/ATM.html vitro and in vivo. In the present study, we synthesized acetylated APTS-coated Fe3O4 NPs with a mean diameter of 6.5 nm, similar to our previous report [33]. The formed acetylated APTS-coated Fe3O4 NPs were used as a labeling agent for in vitro and in vivo MR imaging of C6 glioma cells. The cellular uptake of the acetylated APTS-coated Fe3O4 NPs was confirmed by Prussian blue staining and transmission electron microscopy (TEM) imaging. Combined morphological observation of the cells, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay of cell viability, and flow cytometric Chlormezanone analysis of the cell cycle were used to evaluate the cytotoxicity of the acetylated APTS-coated Fe3O4 NPs. Methods Materials Ferrous chloride tetrahydrate (FeCl2 · 4H2O >99%), ammonia (28% to 30% NH3 in aqueous solution), triethylamine, acetic anhydride, and dimethyl sulfoxide (DMSO) were purchased from Sinopharm Chemical Reagent Co., Ltd (Shanghai, China). The APTS and acetic anhydride were from Acros Organics (Geel, Belgium). C6 glioma cells (a rat C6 glioma cell line) were purchased from the Institute of Biochemistry and Cell Biology at the Chinese Academy of Sciences (Shanghai, China).