References http://genesdev.cshlp.org/content/17/5/545.full.html#related-urls Article cited in: http://genesdev.cshlp.org/content/17/5/545.full.html#ref-list-1 This article cites 228 articles, 79 of which can be accessed free at: service Email alerting click here top right corner of the article or Receive free email alerts when new articles cite this article sign up in the box at the Collections Topic (33 articles) Molecular Physiology and Metabolism  (98 articles) Cancer and Disease Models  Articles on similar topics can be found in the following collections

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Molecular imaging in living subjects: seeing fundamental biological processes in a new light

Size and shape effects in the biodistribution of intravascularly injected particles.

Tens of millions of contrast-enhanced magnetic resonance imaging (MRI) exams are performed annually around the world. The contrast agents, which improve diagnostic accuracy, are almost exclusively small, hydrophilic gadolinium(III) based chelates. In recent years concerns have arisen surrounding the long-term safety of these compounds, and this has spurred research into alternatives. There has also been a push to develop new molecularly targeted contrast agents or agents that can sense pathological changes in the local environment. This comprehensive review describes the state of the art of clinically approved contrast agents, their mechanism of action, and factors influencing their safety. From there we describe different mechanisms of generating MR image contrast such as relaxation, chemical exchange saturation transfer, and direct detection and the types of molecules that are effective for these purposes. Next we describe efforts to make safer contrast agents either by increasing relaxivity, increasing resistance to metal ion release, or by moving to gadolinium(III)-free alternatives. Finally we survey approaches to make contrast agents more specific for pathology either by direct biochemical targeting or by the design of responsive or activatable contrast agents.

Chemistry of MRI Contrast Agents: Current Challenges and New Frontiers

Nanoparticles in cellular drug delivery.

Nanoparticles are tiny materials (<1000 nm in size) that have specific physicochemical properties different to bulk materials of the same composition and such properties make them very attractive for commercial and medical development. However, nanoparticles can act on living cells at the nanolevel resulting not only in biologically desirable, but also in undesirable effects. In contrast to many efforts aimed at exploiting desirable properties of nanoparticles for medicine, there are limited attempts to evaluate potentially undesirable effects of these particles when administered intentionally for medical purposes. Therefore, there is a pressing need for careful consideration of benefits and side effects of the use of nanoparticles in medicine. This review article aims at providing a balanced update of these exciting pharmacological and potentially toxicological developments. The classes of nanoparticles, the current status of nanoparticle use in pharmacology and therapeutics, the demonstrated and potential toxicity of nanoparticles will be discussed.

https://bpspubs.onlinelibrary.wiley.com/doi/pdf/10.1038/sj.bjp.0707130

Nanoparticles: pharmacological and toxicological significance.

Manganese-based MRI contrast agents: past, present and future.

Targeted ultrasonic contrast agents for molecular imaging and therapy.

Targeted acoustic contrast agents are designed to enhance the sensitivity and specificity of ultrasonic diagnoses. We have previously developed a ligand targeted ultrasonic contrast system that is a lipid-encapsulated, liquid-perfluorocarbon emulsion. The emulsion particles are small (250 nm) and have inherently low echogenicity unless bound to a surface by a pretargeted ligand through avidin-biotin interactions. We have recently proposed a simple acoustic transmission line model that treats the emulsion particles as a thin layer over the targeted surface. In this model, the acoustic reflectivity of the sample increases for perfluorocarbons with smaller velocities of longitudinal sound or lower densities. In this study, we measure and report the velocity of longitudinal sound for 20 perfluorocarbons using a broadband phase spectroscopic approach for estimating phase velocities. Experimentally determined velocities ranged from 520/spl plusmn/2 m/sec (perfluorohexane) to 705/spl plusmn/5 m/s (perfluorodecalin). No measurable dispersion was observed over the useful bandwidth of 2 to 22 MHz. Increasing carbon backbone chain length and fluorine substitution with halogens of greater atomic weight increased the measured speed of sound. Our experimental data were consistent (R=0.87) with a published empirical model that predicts velocity as a function of molecular structure. These data provide a rational basis for optimizing targeted perfluorocarbon-based contrast agents and offer further insight into the physical mechanisms responsible for the observed enhancement of surface acoustic reflectivity.

Experimental determination of phase velocity of perfluorocarbons: Applications to targeted contrast agents

Compositions which comprise emulsions of nanoparticles for delivery of membrane-integrating peptides are described. The nanoparticles comprise a liquid hydrophobic core coated with a lipid/surfactant layer which contains the membrane-integrating peptides. Methods to use such compositions are also described.

S.A. Wickline

Papers

Manganese-based MRI contrast agents: past, present and future.

Targeted ultrasonic contrast agents for molecular imaging and therapy.

Targeted ultrasonic contrast agents for molecular imaging and therapy.

Experimental determination of phase velocity of perfluorocarbons: Applications to targeted contrast agents

Nanoparticle delivery systems comprising a hydrophobic core and a lipid/surfactant layer comprising a membrane-lytic peptide