Combining light-activated and chemical treatments, new nanoparticles are more effective against tumors

Wellman's Tayyaba Hasan

A team of researchers in Massachusetts is developing a two-in-one nanoparticle that delivers both a photodynamic therapy (PDT) and a molecular therapy to treat highly resistant tumors--such as those associated with pancreatic cancer--with decreased toxicity.

The researchers, who hail from the Wellman Center for Photomedicine at Massachusetts General Hospital, created a nanoliposome loaded with the drug cabozantinib. What makes it unique is that the liposomal membrane contains the photosensitizer benzoporphyrin derivative, which, when activated by a specific wavelength of light, can damage tumors and their blood supply. The work was published in Nature Nanotechnology.

The combination of the photodynamic and molecular elements of the overall treatment allows for a complementary reaction. The PDT is effective enough, but can also stimulate molecular signaling pathways that can support tumor survival, so that alone is problematic at times. With the chemotherapy contained within the nanoparticle, however, the treatment is more likely to eradicate tumor cells and their source.

"Right now we can say this approach has tremendous potential for patients with locally advanced pancreatic cancer, for whom surgery is not possible," says lead investigator Tayyaba Hasan. "In our Phase I/II clinical studies with PDT alone, tumor destruction was achieved in all cases, and we've seen at least one case where PDT alone induced enough tumor shrinkage to enable follow-up surgery. The more robust tumor reduction and suppression of escape pathways possible with [photoactivable multi-inhibitor nanoliposomes] might enable curative surgery or improve the outcome of chemotherapy to enhance patient survival. But while we are encouraged by these results, this combination in a new nanoconstruct needs more validation before becoming a clinical treatment option."

- here's the release
- get the journal abstract