Nontoxic nanoparticle can deliver and t...(own to inhibit cell growth associated wi...),Health

Several drugs have been shown in cultures to be promising for reducing hardening of the arteries and narrowing of blood vessels after balloon angioplasty. The problem has been in delivering any of these drugs to a target, Butler says.

Ceramide, a chemotherapeutic molecule that initiates cell death in cancer cells, has the ability to slow growth in healthy cells.

Mark Kester, professor of pharmacology, and Jong Yun, associate professor of pharmacology, both at Penn State College of Medicine, have optimized ceramide for both cancer and vascular disease.

Their groups found that by using human vascular smooth muscle cells in vitro, ceramide encapsulated in calcium phosphate nanoparticles reduced growth of muscle cells by up to 80 percent at a dose 25 times lower than ceramide administered freely, without damaging the cells.

The calcium phosphate nanoparticles were developed by James Adair, professor of materials science and engineering, and his students. The nanoparticles have several benefits other drug delivery systems do not, according to lead author Thomas Morgan, graduate student in chemistry.

Unlike quantum dots, which are composed of toxic metals, calcium phosphate is a safe, naturally occurring mineral that already is present in substantial amounts in the bloodstream.

"What distinguishes our method are smaller particles (for uptake into cells), no agglomeration (particles are dispersed evenly in solution), and that we put drugs or dyes inside the particle where they are protected, rather than on the surface," says Morgan. "For reasons we don't yet understand, fluorescent dyes encapsulated within our nanoparticles are four times brighter than free dyes.

"Drugs and dyes are expensive," he continues, "but an advantage of encapsulation is that you need much less of them. We can make high concentrations in the lab, and dilute them way down and still be effective. We eve
'/>"/>