New hydrogel eliminates intractable brain tumors

With a newly developed hydrogel, researchers hope to treat a type of brain tumor called glioblastoma, which is usually associated with very low chances of survival.

The hydrogel is injected directly into the surgical hole after the surgeon has removed the tumor.

The gel releases active substances that help the body fight cancer cells, which may still be hiding in the surrounding tissues.

If the treatment proves effective, it may reduce the need for chemotherapy or radiation after surgery and may also be used against other intractable forms of cancer, such as breast cancer.

Difficult to remove surgically

What makes glioblastoma so problematic is that it is difficult to completely remove tumors by surgery, so cancer stem cells can remain around the removed tumor.

Cancer often returns already two months after surgery.

Thus, the chance of survival is only 25 percent after one year, and after five years, the chance of survival has fallen to less than five percent.

It kills the remaining cancer cells

Once the hydrogel fills the surgical hole, it slowly begins to release its content of nanoparticles, which penetrate and reprogram a type of immune cell called macrophages.

Normally, the job of macrophages is to counter inflammation in the body, but in the context of cancer, macrophages can change their character, suppressing the immune system and promoting tumor growth rather than the other way around.

During the surgical removal of a glioblastoma, inflammation occurs, which causes an influx of macrophages to the surgical site.

At that point, the immune-boosting hydrogel targets its nanoparticles with new instructions for misprogrammed macrophages, so that they no longer favor cancer cells but attack them.

Effective in experiments with mice

Hydrogel nanoparticles target a glycoprotein called CD133, which is a marker of cancer stem cells. At the same time, the nanoparticles contain a special antibody (CD47), which shortens the mechanism that causes macrophages to leave cancer cells alone.

The researchers previously demonstrated in experiments in mice how the hydrogel can cause macrophages in the affected area to wipe out remaining stem cells, which could have developed into new tumors.

The next step will be to test whether the hydrogel therapy also works in humans.