Shape-morphing microrobots deliver drugs to cancer cells

Date:
November 17, 2021
Source:
American Chemical Society
Summary:
Chemotherapy successfully treats many forms of cancer, but the
side effects can wreak havoc on the rest of the body. Delivering
drugs directly to cancer cells could help reduce these unpleasant
symptoms.

Now, in a proof-of-concept study, researchers have made fish-shaped
microrobots that are guided with magnets to cancer cells, where
a pH change triggers them to open their mouths and release their
chemotherapy cargo.



FULL STORY ========================================================================== Chemotherapy successfully treats many forms of cancer, but the side
effects can wreak havoc on the rest of the body. Delivering drugs directly
to cancer cells could help reduce these unpleasant symptoms. Now,
in a proof-of-concept study, researchers reporting in ACS Nano made
fish-shaped microrobots that are guided with magnets to cancer cells,
where a pH change triggers them to open their mouths and release their chemotherapy cargo.


========================================================================== Scientists have previously made microscale (smaller than 100 mym)
robots that can manipulate tiny objects, but most can't change their
shapes to perform complex tasks, such as releasing drugs. Some groups
have made 4D-printed objects (3D-printed devices that change shape in
response to certain stimuli), but they typically perform only simple
actions, and their motion can't be controlled remotely. In a step toward biomedical applications for these devices, Jiawen Li, Li Zhang, Dong Wu
and colleagues wanted to develop shape- morphing microrobots that could
be guided by magnets to specific sites to deliver treatments. Because
tumors exist in acidic microenvironments, the team decided to make the microrobots change shape in response to lowered pH.

So the researchers 4D printed microrobots in the shape of a crab,
butterfly or fish using a pH-responsive hydrogel. 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. Then, they made the microrobots magnetic by placing them
in a suspension of iron oxide nanoparticles.

The researchers demonstrated various capabilities of the microrobots in
several tests. For example, a fish-shaped microrobot had an adjustable
"mouth" that opened and closed. The team showed that they could steer the
fish through simulated blood vessels to reach cancer cells at a specific
region of a petri dish. When they lowered the pH of the surrounding
solution, the fish opened its mouth to release a chemotherapy drug,
which killed nearby cells. Although this study is a promising proof of
concept, the microrobots need to be made even smaller to navigate actual
blood vessels, and a suitable imaging method needs to be identified to
track their movements in the body, the researchers say.

The authors acknowledge funding from the National Natural Science
Foundation of China, the National Key R&D Program of China,
Major Scientific and Technological Projects in Anhui Province, the
Fundamental Research Funds for the Central Universities, the Youth
Innovation Promotion Association of the Chinese Academy of Sciences,
the Hong Kong Research Grants Council, CAS- Croucher Funding Scheme for
Joint Laboratories, the Hong Kong Special Administrative Region of the
People's Republic of China Innovation and Technology Commission and the Multi-scale Medical Robotics Center.

========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Related Multimedia:
* Video_of_the_microrobots ========================================================================== Journal Reference:
1. Chen Xin, Dongdong Jin, Yanlei Hu, Liang Yang, Rui Li, Li Wang,
Zhongguo
Ren, Dawei Wang, Shengyun Ji, Kai Hu, Deng Pan, Hao Wu, Wulin Zhu,
Zuojun Shen, Yucai Wang, Jiawen Li, Li Zhang, Dong Wu, Jiaru Chu.

Environmentally Adaptive Shape-Morphing Microrobots for Localized
Cancer Cell Treatment. ACS Nano, 2021; DOI: 10.1021/acsnano.1c06651 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/11/211117103858.htm

--- up 6 days, 2 hours, 55 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)