In a so-called proof-of-concept study, scientists developed fish-shaped microbots that can help deliver drugs to cancer cells.
As indicated in a ScienceDaily report, the newly invented microbots are guided with magnets to cancer cells "where a pH change" stimulates them to open their mouths and discharge their chemotherapy cargo.
Essentially, chemotherapy is a successful treatment for various cancer forms, although the side effects can inflict disorder on the rest of the body. More so, drug delivery directly to cancer cells could help alleviate disturbing symptoms.
Researchers have previously developed microscale robots that can manipulate very small objects, although most of them cannot change the shapes to carry out multi-faceted tasks like releasing drugs, for one.
4D-Printed Microbots
Some groups have developed 4D-printed objects, although they usually carry out only simple actions, and their movement cannot be remotely regulated or controlled.
Jiawen Li, Li Zhang, Dong Wu, and colleagues, in a step toward these devices' biomedical applications, wanted to create shape-morphing microbots that a magnet could lead to particular areas for the delivery of treatments.
Since tumors exist in acidic microenvironments, the researchers decided to make the microbots change form in reaction to lowered pH.
So, the team 4D printed microbots in the form of a fish, butterfly, or crab, using a pH-responsive hydrogel.
PH-Responsive Shape
By adjusting printing density at certain areas of the shape, such as the edges of the crab's claws or the wings of a butterfly, the researchers encoded pH-responsive shape morphing.
By adjusting the printing density at certain areas of the shape, such as the edges of the crab's claws or the butterfly's wings, the team encoded pH-responsive shape morphing. Next, they made their inventions magnetic by putting them in a suspension of iron oxide nanoparticles.
In their study published in ACS Nano, the study investigators demonstrated different capabilities of the microbots in different tests.
For instance, a fish-shaped microbot was developed with an adjustable mouth that could open and close. The researchers showed that they could steer the fish through replicated blood vessels to reach cancer cells at a particular area of a petri dish.
When the pH of the surrounding solution was lowered, the fish-shaped microbot opened its mouth to release a chemotherapy drug, killing the cells nearby.
This research may be a "promising proof of concept," but the microbots should be developed even tinier to be able to navigate actual blood vessels.
More so, an appropriate imaging method should be identified to track their movements in the body, explained the researchers.
Magnetic Microbots Combating Cancer
This is not the first time that microbots have been developed in the fight against cancer. In 2006, IEEE Spectrum reported said the development of a microbot.
Here, engineers encased medicine in liposomes and had them attached to the bodies of bacteria, as exhibited in the scanning electron microscope image.
Then, they loaded the bacteria into a micelle sack or vesicle. To lead the bacteria-packed bot through an artery, they plotted waypoints on a digitized image of the vessel.
Report about the shape-morphing microbots is shown on the American Chemical Society's YouTube video below:
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