Tiny Melatonin-Filled Bubbles May Enhance Cancer Treatment

Nanostructured lipid carriers (NLCs) filled with melatonin can increase the efficacy of breast cancer chemotherapy.

In a study published in Colloids and Surfaces B: Biointerfaces, researchers used melatonin as an adjuvant to the commonly used chemotherapy drug tamoxifen because of its ability to help kill cancer cells. However, melatonin breaks down quickly and needs to be taken again every few hours.

Although tamoxifen is a common form of treatment, it comes with serious side effects, such as increased risk of stroke, pulmonary embolism, uterine cancer, and vision problems. The most common side effects are hot flashes, weight loss, and an irregular menstruation cycle.

Cancer cells can also develop a resistance to the chemotherapy. To overcome these hurdles, researchers developed NLCs, which are tiny bubbles able to slowly release the melatonin over a period of time.

This enables cancer cells to be continuously destroyed throughout treatment, without having to take any new doses of melatonin.

“We tried to solve both issues by putting melatonin into nanostructures so they can help the chemotherapeutic agent kill more cells,” said corresponding author Nasser Samadi. “By doing this, you can decrease the dose of tamoxifen needed, reducing the severity of the side effects.”

Researchers tested the newly developed NLCs on lab cells, which showed that the NLCs filled with melatonin can more effectively inhibit cancer cell growth compared with melatonin used alone.

Researchers discovered that empty NLCs could not kill the cancer cells without the melatonin; however, they did not cause toxicity to the surrounding tissue.

“Lots of nanostructures these days are toxic to the body or to other cells, but we found no significant toxicity in the empty NLCs,” Samadi said. “The characteristics are very suitable for applying to these kinds of treatments.”

Although the research is still in the early phases, the research team plans to test NLCs on other forms of cancer before using them on animal models.