Sprayable gel may prevent cancer recurrence after surgery

Despite the best efforts of oncologists and surgeons, cancer sometimes comes back after surgery. And surgery is a common treatment for some types of cancer. For example, about 95 percent of early-diagnosed breast cancer requires surgery. It is also often the first line of treatment for brain tumors.

A group of researchers with University of California, Los Angeles (UCLA) have developed a spray gel that contains immune-stimulating drugs. In a study published in the journal Nature Nanotechnology, the gel was effective about 50 percent of the time in stimulating laboratory animals’ immune systems to stop cancer from recurring and inhibiting its metastases.

 “This sprayable gel shows promise against one of the greatest obstacles in curing cancer,” stated lead researcher Zhen Gu, professor of bioengineering at the UCLA Samueli School of Engineering and member of the Jonsson Comprehensive Cancer Center. “One of the trademarks of cancer 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.”

Zhen Gu tested the gel in mice that had advanced melanoma tumors surgically removed. The gel cut the growth of the tumors that remained post-surgery, which led to lower recurrences. After treatment, 50 percent of the mice survived for at least 60 days without tumor regrowth.

The spray gel inhibited recurrence in the area of the body where the tumor was removed, but also in other parts of the body.

The gel isn’t yet ready for human testing. The active ingredient used was an antibody designed to block CD47. In other words, the gel used a checkpoint inhibitor loaded into nanoparticles. The nanoparticles were constructed of calcium carbonate, the primary component of egg shells and in rocks. Calcium carbonate gradually dissolves in surgical wound sites, which are slightly acidic. Calcium carbonate also stimulates the activity of a macrophage that helps remove foreign invaders from the body.

Qian Chen, lead author of the study and a postdoctoral researcher in Zhen Gu’s laboratory, stated, “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.”

The researchers will continue to test the gel in animals to determine optimal dosing, appropriate treatment frequency, and the best combination of nanoparticles before it can be tested on human patients.

Source: biospace.com

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