Introduction High resolution MRI has a low sensitivity for the visualization of low cell numbers in vivo. This is circumvent by the internalization of high concentrations of superparamagnetic iron oxide particles resulting in potential cytotoxic effects or affecting cell biology like differentiation, formation of ROS etc. [1]. In addition, the ability to monitor iron oxide labelled cells in viv...

INTRODUCTION Overproduction of reactive oxygen species (ROS) and decreased antioxidant defense system may contribute to numerous brain disorders such as stroke, epilepsy, Parkinson’s disease, and Alzheimer’s disease. Non-invasive evaluation and visualization of oxidative stress is important to elucidate the role of ROS in brain diseases. In order to visualize the effect of ROS in vivo, nitroxid...

Following the footprint of porphyrin-mediated photodynamic therapy (PDT), paramagnetic metalloporphyrins were originated as tumor seeking contrast agents (CAs) for magnetic resonance imaging (MRI). However, serial research has disproved their tumor selectivity, identified nonviable tissues as their real targets, and eventually elicited new applications in myocardial infarction delineation, tiss...

Time-resolved MRI has had enormous impact in cognitive science and may become a significant tool in basic biological research with the application of new molecular imaging agents. In this paper, we examine the temporal characteristics of MRI contrast agents that could be used in dynamic studies. We consider "smart" T1 contrast agents, T2 agents based on reversible aggregation of superparamagnet...

Angiogenesis has long been accepted as a vital process in the growth and metastasis of tumors. As a result it is the target of several novel anti-cancer medications. Consequently, there is an urgent clinical need to develop accurate, non-invasive imaging techniques to improve the characterization of tumor angiogenesis and the monitoring of the response to anti-angiogenic therapy. Macromolecular...

We report the nanoscale loading and confinement of aquated Gd3+n-ion clusters within ultra-short single-walled carbon nanotubes (US-tubes); these Gd3+n@US-tube species are linear superparamagnetic molecular magnets with Magnetic Resonance Imaging (MRI) efficacies 40 to 90 times larger than any Gd3+-based contrast agent (CA) in current clinical use.

Contrast in MRI relies on differences in the local environment of water and is often enhanced by using contrast agents. We present a simple model for evaluating the minimal contrast agent concentration required to produce "satisfactory" contrast enhancement in magnetic resonance images. Previous strategies have been based largely on empirical results for specific systems. The present tissue con...

Introduction Chemically synthesized magnetic nanoparticles[1], dendrimers[2], and micrometer-sized particles of iron oxide (MPIOs)[3,4] are becoming increasingly popular as T2 * MRI contrast agents. Among them, the larger microparticles are proving useful for labeling single cells for in vivo imaging[5-7]. In particular, the large magnetic moments of MPIOs means that even individual particles c...

Covalent attachment, through a phosphonate anchor, of hydrophilic pegylated dendrons on iron oxide nanoparticles results in versatile, robust, and highly relaxing MRI contrast agents.