shape-changing microrobots deliver chemo drugs directly to cancer cells

Nov 18, 2021

researchers have developed a way of transporting chemotherapy drugs directly to cancer cells via microrobots. at present, most patients undergoing chemotherapy treatment receive the cancer-killing drugs either intravenously or orally, both of which cause a range of unpleasant side effects. this new technology, tested by jiawen li, li zhang, dong wu and colleagues, could revolutionize cancer treatment by delivering drugs only where they’re needed.

in a proof-of-concept study, the scientists tested three microrobots shaped as different tiny animals: a fish, a crab, and a butterfly. the microrobots were 4D printed from pH-responsive hydrogel using a femtosecond laser. using the same principles as 3D printing, 4D printing creates a three-dimensional object that can morph its shape. in this case, the microscopic ‘animals’ changed their form when exposed to a change in pH level—cancer cells are generally more acidic than normal cells.

the researchers also needed a method of guiding the little robots. to achieve this, they submerged the microrobots in a suspension of iron oxide nanoparticles, making them magnetic. guided by a magnet, the ‘fish’ was steered through a petri dish filled with artificial blood vessels. when the fish came to a more acidic part of the solution, it reacted by opening its mouth to release a chemo drug, which killed the cells closest to it.

before the microrobots make it to an actual patient, they need to be made even smaller to navigate real blood vessels, and a suitable imaging method must be identified to track their movements in the body.

the research was published in a paper titled ‘environmentally adaptive shape-morphing microrobots for localized cancer cell treatment’ in journal ACS nano.