Dear Editor, Nanosized particulate systems combining better cancer diagnosis with therapeutic effect are being designed based on the merging of nanotechnology with cellular and molecular techniques. The surface of these nanoscale carriers is often functionalized with biological molecules for stabilization and targeted delivery. The combinations of nano-core and associated functional molecules can cross the cell membrane [1], and the surface of nanomaterials （including coating and associated functional molecules） plays a critical role in determining the outcome of their interactions with cells [2, 3]. Studying the potential effects of nanomaterials in biological systems often requires the administration of nanoparticles into a cell culture system or into living organisms in vivo. It should be noted, however, that under such conditions nanopaticles are known to adsorb proteins from the biological system,
We described a simple one-step process for the synthesis of oleic acid-capped magnetite nanoparticles using the dimethyl sulfoxide(DMSO) to oxidize the precursor Fe^(2+) at 140℃.By adjusting the alkalinity of the reaction system,magnetite nanoparticles with two sizes of 4 and 7 nm could be easily achieved.And the magnetite nanoparticles coated by oleate were well-monodispersed in organic solvent.
Wang, Chun YuHong, Jian MingChen, GongZhang, YuGu, Ning
Encapsulated gas microbubbles are well known as ultrasound contrast agents (UCAs) for medical ultrasound (US) imaging. With the development of shell materials and preparation technologies, the application of microbubbles has been enormously popular in molecular imaging, drug delivery and targeted therapy, etc. The objective of this study is to develop Fe3O4 nanoparticle-inclusion microbubble construct. The in vitro US imaging experiment indicates that the Fe3O4 nanoparticle-inclusion microbubbles have higher US enhancement than those without Fe3O4 nanoparticle-inclusion. According to the microbubble dynamic theory, the acoustic scattering properties can be quantified by scattering cross-section of the shell. The scattering study on Fe3O4 nanoparticle-inclusion microbubbles of different concentration shows that within a certain range of concentration, the scattering cross-section of microbubble increases with the addition of Fe3O4 nanoparticles. When exceeding the concentration range, the ultrasonic characteristic of microbubbles is damped. On the other hand, since Fe3O4 nanoparticles can also serve as the Magnetic Resonance Imaging (MRI) contrast agent, they can be potentially used as contrast agents for the double-modality (MRI and US) clinical studies. However, it is important to control the concentration of Fe3O4 nanoparticles in the shell in order to realize the combined functions of US and MRI.
