in mice, where it inhibited the growth and spread of tumors that had metastasized to the lungs, thereby boosting survival rates compared to control treatments. These microrobots have the potential to revolutionize cancer treatment by targeting tumors with precision and minimizing the side effects of traditional chemotherapy. The study, published in Science Robotics, marks a significant step forward in the field of nanomedicine and paves the way for further research and development of this groundbreaking technology.The findings were published in a study on June 12 in Science Advances. The microrobots are a combination of biology and nanotechnology resulting from a collaboration between professors Joseph Wang and Liangfang Zhang, both from the Aiiso Yufeng Li Family Department of Chemical and Nano Engineering at the UC San Diego Jacobs School of Engineering. In mice, the microrobots inhibited the growth and spread of tumors that had metastasized to the lungs, thereby increasing survival rates compared to control treatments. The researchers chemically attached drug-fResearchers have attached drug-filled nanoparticles to the surface of green algae cells to create microrobots that can swim around in the lungs and deliver drugs to tumors. The nanoparticles are made of biodegradable polymer spheres loaded with doxorubicin and coated with red blood cell membranes, which protect them from the immune system and allow them to stay in the lungs longer to fight tumors. Study co-first author Zhengxing L described the membrane as acting like a camouflage.As a nanoengineering Ph.D. student in both Wang and Zhang’s research groups, I am working on a coating for nanoparticles that mimics the appearance of red blood cells to avoid triggering an immune response. The algae-carrying nanoparticle formulation is deemed safe, with biocompatible materials used in the nanoparticles and the use of U.S. FDA-approved green algae, Chlamydomonas reinhardtii. This study is an extension of previous research by Wang and Zhang’s teams, who used microrobots to treat deadly pneumonia in mice.Microrobots are set to be tested in live animal lungs for safety, according to Wang. In earlier research, the microrobots were used to combat pneumonia-causing bacteria with a different drug and cell membrane combination for the nanoparticles. Now, the team has modified the microrobots to target the spread of cancer cells in the lungs. Zhang stated, “We show that this technology can effectively deliver treatments to fight various deadly lung diseases.” The current research involves mice with melanoma.Mice with lung metastases were given treatment using microrobots, which were delivered to the lungs through a small tube inserted into the windpipe. The treated mice had a median survival time of 37 days, an improvement over the 27-day median survival time of untreated mice and mice that received either the drug alone or drug-filled nanoparticles without algae.
Li stated, “The active swimming motion of the microrobots significantly improved distribution of the drug to the deep lung tissue, while prolonging retention time. This enhanced distribution and prolonged retention time allowed us to reduce the required dose of the drug, minimizing potential side effects.”The team has developed a biohybrid microrobot that can deliver drug-loaded nanoparticles to target lung metastasis. This innovative approach could potentially reduce side effects while maintaining high survival rates. The team is now focusing on testing this treatment in larger animals, with the aim of eventually conducting human clinical trials. The study, titled “Biohybrid microrobots locally and actively deliver drug-loaded nanoparticles to inhibit the progression of lung metastasis,” was co-authored by Fangyu Zhang, Zhongyuan Guo, Zhengxing Li, Hao Luan, Yiyan Yu, Audrey T. Zhu, Shichao Ding, Weiwei Gao, and Ronnie H. Fang. The authors noted that the biohybrid microrobot treatment has the potential to be a game-changer in cancer therapy.The HDTRA1-21-1-0010, which is part of the Defense Threat Reduction Agency’s Joint Science and Technology Office for Chemical and Biological Defense, is collaborating with the National Institutes of Health on the R21AI175904 project.
