Nanocarriers Could Help Drug Overdose Victims

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Nanocarriers Could Help Drug Overdose Victims

Hospitals routinely treat patients suffering from drug overdoses. However, in many cases antidotes to the drug do not exist and patients need to have their stomachs pumped or undergo other painful, invasive procedures. Now, a scientist in Canada has proposed using nanoparticles to detoxify tissues using a method that involves intravenously injecting the particles into the body. The nanomaterials would circulate in the bloodstream, bind to the drug and then be safely eliminated, mainly by the kidneys or liver depending on their size.

Drug overdoses account for a staggering 40% of toxic exposures in humans. Unfortunately, antidotes only exist for a relatively small number of drugs and treatments mainly consist of pumping the stomach or irrigating the bowel, administering activated charcoal and removing toxins by haemodialysis. All such treatments are invasive and require specialized equipment.

There could be an alternative though: nanoparticles injected into the bloodstream. "At the moment we are testing different types of nanocarriers (nanovesicles and nanocapsules) for drug detoxification applications," Jean-Christophe Leroux of the University of Montreal told nanotechweb.org. "So far we have shown that appropriately designed nanocarriers can extract overdosed drugs from tissues after a simple intravenous injection." The particles, with their cargo of bound drugs, would then exit the body after degradation.

Tailored particles

Thanks to their small size of between 50 and 100nm, the nanoparticles can circulate in the bloodstream without blocking blood vessels. Once in the bloodstream, they travel into organs and tissues. The particles can be tailored to selectively bind to a particular drug and lower its concentration in the intoxicated area. They can also be designed to take up more than one drug at once, making them useful for removing several different compounds.

Leroux says that he has tested the technique in an ex vivo model of heart intoxication to an antidepressant. He demonstrated that the recovery is much faster when the heart is perfused with a solution of nanocarrier compared to a buffer solution without nanoparticles.

Potential limitations include interactions of the nanoparticles with other drugs that might have been given to the patient to treat symptoms caused by the overdose.

Leroux now plans to test the technique in larger animal models, such as pigs, in which real-life overdose conditions can be mimicked.

This work was originally reported in Nature Nanotechnology.

Source: http://www.nanowerk.com/

Story posted: 24th January 2008