Swimming microrobots deliver cancer-fighting drugs to metastatic lung tumors in mice

Engineers at the University of California San Diego have developed microscopic robots, known as microrobots, capable of swimming through the lungs to deliver cancer-fighting medication directly to metastatic tumors.

This approach has shown promise 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.

The microrobots are an ingenious combination of biology and nanotechnology. To create the microrobots, researchers chemically attached drug-filled nanoparticles to the surface of green algae cells.

The algae, which provide the microrobots with their movement, enable the nanoparticles to efficiently swim around in the lungs and deliver their therapeutic payload to tumors.

The nanoparticles are made of tiny biodegradable polymer spheres, which are loaded with the chemotherapeutic drug doxorubicin and coated with red blood cell membranes. This coating serves a critical function: it protects the nanoparticles from the immune system, allowing them to stay in the lungs long enough to exert their anti-tumor effects.

This formulation of nanoparticle-carrying algae is safe, the researchers noted. The materials used to make the nanoparticles are biocompatible while the green algae employed, Chlamydomonas reinhardtii, are recognized as safe for use by the U.S. Food and Drug Administration.

Image source: Zhengxing Li.