Cholesterol and Nanoparticles

Posted on February 22, 2010 by Robert Oszakiewski

We are all familiar, at this point in time, with the concept of "good" (HDL) and "bad" (LDL)cholesterol and with the effects of a build up of "bad" cholesterol on the walls of arteries and other blood vessels. Cardiovascular disease is now the leading cause of death in the United States, ahead of cancer.

According to an article published in late November in the New York Times, research at Northwestern University, under the direction of Drs. C. Shad Thaxton and Chad A. Mirkin, and at the Mount Sinai School of Medicine under the direction of Dr. Willem J.M. Mulder, may lead to new  tools for the diagnosis and treatment of cardiovascular disease.

Drs. Thaxton and Mirkin's work has focused on creating synthetic versions of the HDL (good cholesterol) molecule using gold nanoparticles to replace the fatty core usually found in the HDL molecule. The altered HDL molecule has been demonstrated in a pilot study to be effective in removing plaque build-ups from blood vessels, by absorbing the LDL cholesterol, just as naturally occurring HDL molecules would.

The research at Mt. Sinai has focused on developing HDL-like nanoparticles for use in different types of imaging; gold nanocrystals were most effective when used in computer tomography while iron oxide nanocrystals were more effective with MRIs. The goal of Dr. Mulder's research is to improve the imaging of hardening of the arteries due to the build-up of plaques

The potential for using the HDL-nanoparticles as treatment for cardiovascular disease, according to Dr. William O'Neill, Executive Dean for Clinical Affairs at the Miller School of Medicine at the University of Miami, "Could revolutionize cardiology".

However, as both Dr. Andre Nel, Director of the Center for Environmental Implications of Nanotechnology at UCLA and Professor Vincent M. Rotello a the University of Massachusetts at Amherst, caution, further study on the possible effects of nanoparticle accumulation in the body need to be done before wide spread use the nano-HDL in treatment for cardiovascular disease, along with exercise, diet changes etc can occur.

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Micelle, my micelle

Posted on June 19, 2009 by Robert Oszakiewski

There's been a sort of a medical theme running through this week's entries, so, to close out medical week, we turn to an article by David Peters et al,  advanced published on PNAS website, "Targeting atherosclerosis by using modular, multifunctional micelles". Much as other nanoparticles may be targeted at tumors (see "Targeting Tumors"), so micelles may be targeted at plaque in blood vessels.

As the article describes, lab mice fed a high fat diet were treated for plaque formation using micelles with peptides that would seek out and attach themselves at the weakest point of the plaque, delivering anticoagulants to reduce the formations. The results of the experiments

Micelles coated with the CREKA peptide were able to specifically target diseased vasculature in ApoE-null mice. . . . micelles targeted with the CREKA peptide present a potentially useful approach to targeting atherosclerotic plaques.

. . .  the CREKA micelle platform may be useful in reducing the clotting tendency in plaques and could potentially also reduce the risk of thrombus formation on plaque rupture. Also the targeting makes it possible to lower the dose, which should reduce the risk of bleeding complications.

This study, along with earlier ones on targeting nanoparticles to seek out tumors to more effectively deliver chemotherapy treatments, seems to indicate that the best use of nanoparticles in medicine is as delivery systems.

And for anyone below a certain age who didn't get the reference in the title, take a look here. Ah, Lennon and McCartney. They just don't write them like this anymore.

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