The team tested this potentially groundbreaking treatment in mice, but they add that clinical trials in human cancer patients could start by fall 2022. The tiny implants continuously deliver a high dose of interleukin-2 to the tumor region in the patient. Interleukin-2 is a natural compound which activates the immune system's white blood cells to fight the cancer.

Researchers say these drug-producing beads are capable of being implanted in a minimally invasive surgery. The bioengineers also designed the implants with a protective shell that prevents the immune system from mistakenly attacking the drug factories. They also used components that scientists already know are safe for use in humans to hopefully speed up the time it will take to get this treatment through the testing phase.

"We just administer once, but the drug factories keep making the dose every day, where it's needed until the cancer is eliminated," says study co-author Omid Veiseh in a university release. "Once we determined the correct dose — how many factories we needed — we were able to eradicate tumors in 100% of animals with ovarian cancer and in seven of eight animals with colorectal cancer."