It’s an adhesive patch that is way more than a Band-Aid. And it’s not just one of those medicated patches that are used to deliver nicotine, a contraceptive, or a pain killer. This patch is a triple-threat aimed straight at cancer. Once it is slapped on a tumor, it delivers a combination of drug, gene, and light-based therapy.
The patch, which was developed by scientists based at MIT, represents a new kind of cancer treatment, which typically involves the use of systemic, or whole-body, approaches such as chemotherapeutics. By delivering therapy locally, releasing tiny amounts of drug to a tumor site, the new patch can avoid the side effects that often accompany systemic treatments. And though the amounts of drug delivered may be said to be “tiny,” they are, effectively, more concentrated.
Thus far, the patch has been used in an animal model of colon cancer, which is often treated surgically, even though surgical interventions often fail to remove tumors completely, leaving open the possibility of recurrence and metastasis. While many patients remain cancer-free for months or even years after surgery, tumors are known to recur in up to 50% of cases.
To prevent the recurrence of tumors after surgery, conventional therapies such as chemotherapy fail to differentiate sufficiently between healthy and cancerous cells. Hence the adverse side effects. Also, with systemically administered treatments, only a small portion of the drug reaches the tumor site itself, meaning that the primary tumor is not treated as effectively as it should be.
“[We tend to treat] both the source of the cancer—the tumor—and the metastases resulting from that source, in a suboptimal manner,” said Natalie Artzi, Ph.D., a research scientist at MIT's Institute for Medical Engineering and Science (IMES) and an assistant professor of medicine at Brigham and Women's Hospital, who led the effort to develop the new patch. “That is what prompted us to think a little bit differently, to look at how we can leverage advancements in materials science, and in particular nanotechnology, to treat the primary tumor in a local and sustained manner.”
Dr. Artzi and her colleagues described their work in an article that appeared July 25 in the journal Nature Materials, in an article entitled, “Local Triple-Combination Therapy Results in Tumour Regression and Prevents Recurrence in a Colon Cancer Model.” The article detailed how the researchers used a prophylactic hydrogel patch to deliver a combination of gene, drug, and phototherapy in a colon cancer mouse model. The patch, the scientists reported, led to “complete tumour remission when applied to nonresected tumours and to the absence of tumour recurrence when applied following tumour resection.”
“The adhesive hydrogel patch enhanced the stability and provided local delivery of embedded nanoparticles,” the authors added. “Spherical gold nanoparticles were used as a first wave of treatment to deliver siRNAs against Kras, a key oncogene driver, and rod-shaped gold nanoparticles mediated the conversion of near-infrared radiation into heat, causing the release of a chemotherapeutic as well as thermally induced cell damage.”
The researchers envision that a clinician could remove the tumor, and then apply the patch to the inner surface of the colon, to ensure that no cells that are likely to cause cancer recurrence remain at the site. As the patch degrades, it will gradually release the various therapies.
Dr. Artzi asserted that the patch can also serve as a neoadjuvant, a therapy designed to shrink tumors prior to their resection.
When the researchers tested the treatment in mice, they found that in 40% of cases where the patch was not applied after tumor removal, the cancer returned. But when the patch was applied after surgery, the treatment resulted in complete remission. Indeed, even when the tumor was not removed, the triple-combination therapy alone was enough to destroy it.
Their local, triple-combination approach to cancer therapy, the MIT scientists concluded, can be adapted to other cancer cell types and to molecular targets associated with disease progression. “This administration modality would enable, at least in early-stage cancer patients, the avoidance of open field surgery and colon resection,” emphasized Dr. Artzi. “Local application of the triple therapy could thus improve patients' quality of life and therapeutic outcome.”