Engineers on the College of California San Diego have developed microscopic robots, often called microrobots, able to swimming via the lungs to ship cancer-fighting medicine on to metastatic tumors. This strategy has proven promise in mice, the place it inhibited the expansion and unfold of tumors that had metastasized to the lungs, thereby boosting survival charges in comparison with management therapies.
The findings are detailed in a paper printed on June 12 in Science Advances.
The microrobots are an ingenious mixture of biology and nanotechnology. They’re a joint effort between the labs of Joseph Wang and Liangfang Zhang, each professors within the Aiiso Yufeng Li Household Division of Chemical and Nano Engineering on the UC San Diego Jacobs Faculty of Engineering.
To create the microrobots, researchers chemically connected drug-filled nanoparticles to the floor of inexperienced algae cells. The algae, which give the microrobots with their motion, allow the nanoparticles to effectively swim round within the lungs and ship their therapeutic payload to tumors.
The nanoparticles are made from tiny biodegradable polymer spheres, that are loaded with the chemotherapeutic drug doxorubicin and coated with pink blood cell membranes. This coating serves a important operate: it protects the nanoparticles from the immune system, permitting them to remain within the lungs lengthy sufficient to exert their anti-tumor results. “It acts as a camouflage,” stated examine co-first creator Zhengxing Li, who’s a nanoengineering Ph.D. pupil in each Wang and Zhang’s analysis teams. “This coating makes the nanoparticle appear to be a pink blood cell from the physique, so it won’t set off an immune response.”
This formulation of nanoparticle-carrying algae is secure, the researchers famous. The supplies used to make the nanoparticles are biocompatible whereas the inexperienced algae employed, Chlamydomonas reinhardtii, are acknowledged as secure to be used by the U.S. Meals and Drug Administration.
This examine builds on prior work by Wang and Zhang’s groups utilizing related microrobots to deal with lethal pneumonia in mice. “These have been the primary microrobots to be safely examined within the lungs of reside animals,” stated Wang.
In earlier work, the microrobots fought the unfold of pneumonia-causing micro organism utilizing a special drug and cell membrane mixture for the nanoparticles. By tweaking these elements, the staff has now tailor-made the microrobots to struggle the unfold of most cancers cells within the lungs. “We show that this can be a platform know-how that may actively and effectively ship therapeutics all through your entire lung tissue to fight several types of lethal illnesses within the lungs,” stated Zhang.
Within the present examine, mice with melanoma that had metastasized to the lungs have been handled with the microrobots, which have been administered to the lungs via a small tube inserted into the windpipe. Handled mice skilled a median survival time of 37 days, an enchancment over the 27-day median survival time noticed in untreated mice, in addition to mice that acquired both the drug alone or drug-filled nanoparticles with out algae.
“The energetic swimming movement of the microrobots considerably improved distribution of the drug to the deep lung tissue, whereas prolonging retention time,” stated Li. “This enhanced distribution and extended retention time allowed us to scale back the required drug dosage, doubtlessly decreasing unwanted effects whereas sustaining excessive survival efficacy.”
Shifting ahead, the staff is engaged on advancing this microrobot therapy to trials in bigger animals, with the last word objective of human medical trials.
