Superparamagnetic Nanoparticles as High Efficiency Magnetic Resonance Imaging T Contrast Agent.

Nanoparticle-based magnetic resonance imaging T negative agents are of great interest, and much effort is devoted to increasing cell-loading capability while maintaining low cytotoxicity. Herein, two classes of mixed-ligand protected magnetic-responsive, bimetallic gold/iron nanoparticles (Au/Fe NPs) synthesized by a two-step method are presented. Their structure, surface composition, and magnetic properties are characterized.

Electrical method to quantify nanoparticle interaction with lipid bilayers.

Understanding as well as rapidly screening the interaction of nanoparticles with cell membranes is of central importance for biological applications such as drug and gene delivery. Recently, we have shown that "striped" mixed-monolayer-coated gold nanoparticles spontaneously penetrate a variety of cell membranes through a passive pathway. Here, we report an electrical approach to screen and readily quantify the interaction between nanoparticles and bilayer lipid membranes.

Erythrocyte incubation as a method for free-dye presence determination in fluorescently labeled nanoparticles.

The field of nanotheranostics encompasses the integration of nanosized carriers in cancer imaging, diagnosis, and therapy. The use of nanomedicines for theranostic application typically depends on direct visualization of the nanocarriers. Normally fluorescent probes are attached to nanocarriers for biodistribution measurement through fluorescence imaging.

Dynamic cellular uptake of mixed-monolayer protected nanoparticles.

Nanoparticles (NPs) are gaining increasing attention for potential application in medicine; consequently, studying their interaction with cells is of central importance. We found that both ligand arrangement and composition on gold nanoparticles play a crucial role in their cellular internalization. In our previous investigation, we showed that 66-34OT nanoparticles coated with stripe-like domains of hydrophobic (octanethiol, OT, 34%) and hydrophilic (11-mercaptoundecane sulfonate, MUS, 66%) ligands permeated through the cellular lipid bilayer via passive diffusion, in addition to endo-/pino-cytosis.