Tiny Drugs, Bursts of Light

Glioblastoma multiforme treatment using photodynamic theranostics

(RxWiki News) Cancers are greedy little cells, consuming more than their fair share of everything available. A treatment recently developed takes advantage of that, and then uses special, focused light to destroy tumors.

Scientists in the past decade have developed a field they call theranostics, combining the word therapy and diagnostic to refer to a treatment that also helps doctors understand better what disease they are currently dealing with.

"Ask your oncologist about theranostics."

Researchers from Case Western University outlined a two stage process to treat an aggressive brain cancer called glioblastoma multiforme, using nanotechnology to destroy cancer cells. 

The first stage delivers a nanometer-sized drug that accumulates in the tumor. The second stage activates the drug, causing widespread tumor death.

While the treatment is still in the experimental stages of development in the laboratory, testing has shown that the concept works well. The tumor cells were able to be targeted to the brain tumor, easily crossing the blood brain barrier that stops most cancer drugs in their tracks.

The technique works by attaching miniscule particles of gold to each molecule of drug, allowing it to cross the blood brain barrier.

Once the drug filters into the brain, it begins to build up in the tumor a lot more quickly than in other parts of the brain.

During brain surgery, surgeons shine a special type of light on the tumor, which activates the drug phthalocyanine 4 (Pc 4), avoiding the need to perform surgery directly on the brain itself.

So far the researchers state they have been able to target tumors specifically, meaning that normal brain cells would be far less affected by this treatment, especially in comparison to traditional surgery.

By combining the accumulation of the drug with the light activation, tumor destruction becomes very specific, an important quality in any surgery dealing with brain tissue. Further development of this light-activated nanoparticle drug would be a step up from current treatments.

Currently, drastic treatments for glioblastoma multiforme have used viruses to kill the tumor, or intense amounts of chemotherapy, and radiation, but so far scientists have been unable to stop this very aggressive stage of brain cancer for very long. 

Research presented at conferences is considered preliminary until published in a peer-reviewed journal.

No financial disclosures were made by the study authors.

Review Date: 
May 17, 2012