New cancer treatment uses cells and magnets

There are a lot of things that magnets have inspired - compasses, hard disk drives, and even those promotional fridge magnets that come with Chinese takeout. In the popular X-Men series, arch-villain Magneto has the power to control magnetic fields.

A team of Korean scientists are developing ways to use magnetic fields to combat cancer.

Supported by the Ministry of Science, ICT and Future Planning, a team at Chonnam National University developed 20-micrometer-sized robots that fight cancer cell. They are controlled by magnetic fields outside a patient’s body.

Although dubbed “robots,” they are actually macrophages, white blood cells that engulf and digest pathogens, part of the human immune system. Using this property, scientists let macrophages devour nanoparticles previously injected with anti-cancer drugs, creating cancer combatants.

The macrophages were also loaded with iron oxides that would enable them to be controlled with magnetic fields.

Under chemotherapy, treating malignant, cancerous tumors is difficult because blood vessels formed by tumors are abnormal. Drug molecules can’t travel very well in these blood vessels because they are not structurally differentiated like normal arteries, veins and capillaries. They are irregular and exist to let the tumor extract nutrition from the body to grow in size.

Magnetic fields can allow the anti-cancer macrophages to infiltrate even the central region of a tumor, which normally lacks blood vessels through which drug molecules may travel.

According to a research article, the magnetic field can “physically guide the therapeutic drugs to target disease region.” Another positive effect of the treatment is that it “reduces the side effects of chemotherapy by low drug concentration of other organs.”

Professor Park Suk-ho, who led the research team, said, “24 hours after we introduced the micro robots into cancerous organs, 45 percent of colorectal cancer cells and 40 percent of breast cancer cells have diminished.” He explained that in addition to the macrophages attacking cancer cells, anti-cancer drugs stored in them also played a role.

This research was published online on June 27 in Scientific Reports, an open access journal published by the Nature. It followed another team of engineers from Chonnam National University led by Park Jong-oh, which developed bacteria-based microrobots, or bacteriobots, in an effort to fight cancerous tumors.

Outside of Korea, a team of scientists from Israel’s Bar-Ilan University began human trials including drug-delivering nano-size robots, or nanobots, earlier this year. They are made of DNA that plays the role of a vessel for cancer-treating drugs. Unlike chemotherapy and radiation therapy, which cause damage to healthy and cancerous cells alike, DNA nanobots can attack selectively and precisely.

BY MOON HEE-CHUL, LEE DONG-EUN [lee.dongeun@joongang.co.kr]