ILLUSTRATION BY RAISSA MACASIEB-LUDWIG
Microswimmers Deliver Targeted Cancer Solutions
A
Mason Engineering researcher has discovered that artificial microswimmers accumulate where their speed is minimized, an idea that could have implications for improving the efficacy of targeted cancer therapy.
Jeff Moran, an assistant professor of mechanical engineering in the College of Engineering and Computing, and colleagues from the University of Washington in Seattle studied self-propelled half-platinum/half-gold rods that “swim” in water using hydrogen peroxide as a fuel. The more peroxide there is, the faster the swimming; without peroxide in pure water, the rods don’t swim. In this work, the researchers set out to understand what happens when these artificial microswimmers are placed in a fluid reservoir containing a gradient of hydrogen peroxide— lots of peroxide on one side, not much on the other side.
16 COLLEGE OF ENGINEERING AND COMPUTING ANNUAL REPORT 2021
They found that, predictably, the microswimmers swam faster and in random directions in regions with a high peroxide concentration, says Moran, whose research was published in Scientific Reports. In contrast, in low-concentration regions, the rods slowed down and accumulated in these regions over the course of a few minutes. The results suggest a simple strategy to make microswimmers passively accumulate in specific regions, an idea that might have useful, practical applications, he says. Living cells can autonomously swim toward regions of high chemical concentration, a process called chemotaxis. “For example, your immune cells use chemotaxis to detect and swim toward sites of injury, so they can initiate tissue repair,” Moran says.
