A patch that delivers drug, gene, and light-based therapy to tumor sites.

Its estimated that one in 20 people will develop colorectal cancer in their lifetime, making it the third-most prevalent form of the disease in the U.S. In Europe, it is the second-most common form of cancer. The most widely used first line of treatment is surgery, but this can result in incomplete removal of the tumor. Cancer cells can be left behind, potentially leading to recurrence and increased risk of metastasis. Indeed, while many patients remain cancer-free for months or even years after surgery, tumors are known to recur in up to 50 percent of cases. Conventional therapies used to prevent tumors recurring after surgery do not sufficiently differentiate between healthy and cancerous cells, leading to serious side effects. A research published in the journal Nature Materials shows how researchers at MIT describe an adhesive patch that can stick to the tumor site, either before or after surgery, to deliver a triple-combination of drug, gene, and photo (light-based) therapy. The patch has a triple combination therapy locally at the tumor site, and this will increase the efficacy of the treatment. The general approach to cancer treatment is the use of systemic, therapies such as chemotherapy drugs, but the lack of specificity of anticancer drugs means they produce undesired side effects when systemically administered.This coupled with the fact that only a small portion of the drugs reaches the tumor site makes this approach ineffective. The researchers made a triple-therapy hydrogel patch, which can be used to treat tumors locally. This is particularly effective as it can treat not only the tumor itself but any cells left at the site after surgery, preventing the cancer from recurring or metastasizing in the future. Firstly, the patch contains gold nanorods, which heat up when near-infrared radiation is applied to the local area. This is used to thermally kill or destroy, the tumor.These nanorods are also equipped with a chemotherapy drug, which is released when they are heated, to target the tumor and its surrounding cells. Finally, gold nanospheres that do not heat up in response to the near-infrared radiation are used to deliver RNA, or gene therapy to the site, in order to silence an important oncogene in colorectal cancer. Oncogenes are genes that can cause healthy cells to transform into tumor cells. 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. The patch can also serve as a neoadjuvant, a therapy designed to shrink tumors prior to their resection. When the treatment was done in mice, 40 % of cases where the patch was not applied after tumor removal, the cancer returned. When the patch was applied after surgery, the treatment resulted in complete remission,and even when the tumor was not removed, the triple-action therapy alone was enough to destroy it.