Microrobots deliver cancer drugs to lung tumors in mice
Engineers at the University of California San Diego have created tiny microrobots that can swim through the lungs to deliver cancer-fighting drugs directly to tumors. This method reduced tumor growth and spread in mice, improving survival rates. These microrobots are a blend of biology and nanotechnology, developed by the labs of professors Joseph Wang and Liangfang Zhang at UC San Diego.
Researchers created microrobots by attaching drug-filled nanoparticles to green algae cells. The algae help the microrobots move around the lungs and deliver the drugs to tumors. These nanoparticles are biodegradable polymer spheres loaded with the cancer drug doxorubicin and coated with red blood cell membranes.
This coating protects them from the immune system, allowing them to stay in the lungs and fight tumors effectively. “It acts as a camouflage,” explained Zhengxing Li, a nanoengineering Ph.D. student involved in the study.
The researchers noted that the nanoparticle-carrying algae are safe. The nanoparticles are biocompatible, and the green algae used, Chlamydomonas reinhardtii, are FDA-approved. This study builds on previous work by Wang and Zhang’s teams using similar microrobots to treat pneumonia in mice.
Those earlier microrobots were the first to be safely tested in animal lungs. By modifying the drug and cell membrane components, the team has adapted the microrobots to fight lung cancer cells. This platform can efficiently deliver treatments throughout the lungs for various deadly diseases.
In the study, mice with melanoma that had spread to the lungs were treated with microrobots delivered via a small tube into the windpipe. Treated mice had a median survival of 37 days, compared to 27 days for untreated mice and those receiving only the drug or drug-filled nanoparticles without algae.
The microrobots’ active swimming improved drug distribution and retention in lung tissue, allowing for lower drug doses and potentially fewer side effects. The team aims to advance this treatment to more extensive animal trials and, eventually, human clinical trials.
In conclusion, swimming microrobots successfully delivered cancer-fighting drugs to metastatic lung tumors in mice, improving survival rates by enhancing drug distribution and retention in lung tissue. This promising approach may lead to more effective cancer treatments with fewer side effects, and the researchers aim to advance to more extensive animal trials and, eventually, human clinical trials.
Journal reference:
- FANGYU ZHANG, ZHONGYUAN GUO et al. Biohybrid microrobots locally and actively deliver drug-loaded nanoparticles to inhibit the progression of lung metastasis. Science Advances. DOI: 10.1126/sciadv.adn6157.
