The first step in many cancer treatments is to surgically remove the tumorous tissue, however this often isn't enough in itself. As long as a few cells of cancer remain the tumors often grow back, but an innovative new spray gel designed to be administered onto a cancerous site during surgery may help prevent the tumors recurring.

Led by a team of scientists from UCLA, the researchers developed a novel gel designed to help the body's immune system better target, and kill, cancer cells that remain after surgery. The gel is loaded with nanoparticles made up of calcium carbonate, designed to slowly dissolve in human tissue.

The nanoparticles are filled with antibodies that inhibit a specific protein the cancer cells use to hide from our immune system. CD47 is a protein important in a range of different cellular processes across the human body. It is often euphemistically referred to as the "don't-eat-me" signal, helping our immune system avoid attacking things it shouldn't.

However, cancer cells often cleverly over-express CD47 as a way to avoid immune detection. By directly applying a gel with CD47 antibodies onto a site after removing a tumor, our body's immune system can better find and eliminate any remaining cancerous cells.

"This sprayable gel shows promise against one of the greatest obstacles in curing cancer," says Zhen Gu, a professor of bioengineering at the UCLA Samueli School of Engineering and one of the researchers on the project. "One of the trademarks of cancers is that it spreads. In fact, around 90 percent of people with cancerous tumors end up dying because of tumor recurrence or metastasis. Being able to develop something that helps lower this risk for this to occur and has low toxicity is especially gratifying."

Initial tests in mice have been extremely promising, with the gel preventing tumor regrowth and increasing long-term survival rates in 50 percent of the animals. Interestingly, these early animal trials also revealed the gel seems to prevent the cancer from metastasizing across the body as well as stifling local regrowth.

"We also learned that the gel could activate T cells in the immune system to get them to work together as another line of attack against lingering cancer cells," explains Qian Chen, lead author on the study.

There is still some work to be done before the research can move to human trials with the gel. Refinements are planned to optimize the nanoparticles and find the most effective dose. Nevertheless, this is potentially an exciting new tool that could be invaluable in helping doctors more effectively control cancer regrowth after surgery and limit metastatic developments.

The research was published in the journal Nature Nanotechnology.

Source: UCLA