Improving chemotherapy: Combo of 'popping' nanoballoons, lasers can effectively treat cancer

Chemotherapy: One of the most effective weapons doctors have against cancer is also one of the most toxic.

Although chemotherapy drugs can successfully stop or slow the growth of cancer cells in the body, they can also harm healthy cells in the process – leading to unwanted side effects, such as fatigue, nausea and hair loss.

But now, there may be a way of providing patients with a more focused form of chemotherapy – by using innovative “nanoballoons” and lasers. Developed by researchers at the University at Buffalo, these miniscule particles can deliver anti-cancer medications straight to the tumor itself, without causing unwanted damage along the way.

“In the past 10 or 20 years, there’s been a lot of interest in using nanoparticles in order to carry drugs to the tumor, and part of the hope is it reduces some of the toxic side effects of the drugs,” corresponding author Jonathan Lovell, assistant professor of biomedical engineering at the University of Buffalo, told “…That’s the problem [now]: Only a very small fraction of the drugs that you actually give to a patient ends up in the tumor – so if you’re lucky, it’ll be a few percent, but maybe even less than that.”

Harnessing this nanoparticle concept, Lovell and his team developed their own nanoballoons – also referred to as PoP-liposomes.  Approximately 1,000 times smaller than a human hair, the balloons are comprised of chlorophyll, an organic pigment found in green plants, and phospholipid, a fat similar to vegetable oil.  Because of this unique composition, the nanoballoons are capable of completely encapsulating anti-cancer drugs, shielding them from other healthy bodily systems.

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Once the drugs are trapped inside these containers, the tiny balloons are injected into the bloodstream and diffuse throughout the body.  Then, the researchers hit the PoP-liposomes with a red laser right at the site of the targeted tumor – triggering the balloons to “pop” open and release the chemotherapy drugs.

Lovell noted that the researchers are still not entirely sure how the lasers generate this popping response, but they believe it all revolves around the balloons’ chlorophyll component.

“One thing we’re sure of in this research paper is it’s not related to heat at all. There have been somewhat similar approaches to this done – trying to use heat to pop open similar types of containers. But this one is purely based on light,” Lovell said.  “Probably when the nanoballoons are absorbing all that light…the actual electrons [in the chlorophyll] go into a different electronic state.  When that occurs, the nanoballoons just become prone to opening up.”

Conversely, once the red laser is turned off, the nanoballoons close back up, trapping many of the proteins and molecules in their surrounding environment.  The researchers hope to retrieve the nanoballoons by drawing blood or taking a biopsy – and analyze their contents to get a “chemical snapshot” of the tumor.

To demonstrate the effectiveness of this method, Lovell and his team tested their invention on mice that had tumors growing on the surface of their skin.  Using their laser/nanoballoon combination, the mice were completely cured of their cancers after a few treatments.  And, since the chemotherapy drugs did not affect the rest of the body’s systems, the researchers did not need to use as much of the drug to get their desired results.

Given the study’s success, Lovell believes their drug delivery technique could have a very significant effect on the future of cancer treatment.

“I think the most immediate impact would be affecting people who are suffering from conditions where a tumor cannot be removed, but that tumor is causing extreme quality of life issues, such as bowel blockages and things like pancreas malfunction,” Lovell said. “…And eventually, if there are other tumors that are locally advanced, but haven’t spread to distant places, this may be a good treatment to treat a big tumor before it spreads.”

Perhaps most importantly, Lovell said the nanoballoons will decrease drug toxicity in cancer patients exponentially and give physicians greater control over the administration of cancer treatment.

“It would allow you to have a mini submarine [full of drugs], and you can open the door on command and close the door on command.”

The research was published April 3 in the journal Nature Communications.