Researchers create a way to place living cells inside the body under surveillance

Researchers at King Abdullah University of Science and Technology (KAUST) have learned how to noninvasively track in real-time over many days living cells inside a living organism. The technique they developed uses magnetic core-shell iron nanowire as non-toxic contrast agents that can be implanted in the living cells. They can determine those cells' locations inside a living organism when scanned by an MRI.The researchers believe that the technique could have applications ranging from studying and treating cancer to tracking live-cell medical treatments, such as stem cell therapies. Researchers were also able to show that the core-shell iron nanowires can selectively kill cancer cells with a combination attack that delivers an anticancer drug into the target cells while puncturing the cell's membrane and unleashing a blast of heat.

In collaboration with other researchers, the team has shown that the same type of iron core, iron-oxide shell nanowires, can be used for noninvasive medical imaging. Nanowires can potentially be used as "theranostic" agents that can identify, track, and target cells.

The nanowires perform well as MRI contrast agents, even at very low concentrations. The magnetic response can be tuned by altering the thickness of the nanowire shell. The biocompatibility of the wires enables long-term tracking of the live cells.

Researchers say that the nanowires interacted with cells without compromising their survival, functionality, or capacity to proliferate. Labeled cells were able to be tracked in cell cultures or once injected into a living animal. The strong magnetization of the nanowires enabled the tracing of the exact location of ten labeled cells inside the brain of a mouse. The nanowires can also be guided to a specific location using magnetic systems to carry drugs and can be heated with a laser.