Fangyu Zhang

Fangyu Zhang, 34, engineered single-cell, self-propelled microalgae into a swarm of swimming biorobots that can be used to treat bacterial pneumonia and other infections before being dissolved naturally by the body. Now he’s working on similar treatments for cancer.

This new approach has advantages over intravenous antibiotics and chemotherapy. In the case of lung infections, which Zhang and his team studied in a mouse model, the antibiotic dose needed to treat pneumonia was reduced by over 99.9%. And targeting cancer cells with chemotherapy-laden biorobots could produce fewer side effects than intravenous treatments while boosting the odds of successful cures.

Zhang’s breakthrough depends on a few steps. First, he and his team created drug-infused nanocoatings that could survive being passed through the stomach or exposed to the lungs. Next, they attached the drug-delivery coatings to the surface of a microscopic green alga, Chlamydomonas reinhardtii, that moves around by flapping its two tail-like structures, or flagella. The rest is up to nature: The armor-wearing, drug-coated biorobots are applied in the trachea or esophagus, where they can swim toward a precise target. 

“In the lung area,” says Zhang, “it then takes about 72 hours for the microalgae to totally dissolve.” 

Zhang’s approach isn’t really a single treatment; he’s created a biorobot platform. “The algae surface has a lot of functional groups,” he says, “so we can target specific cells.” Some of those functional groups—think of modules that can be swapped out to change what the biorobot sticks to, or avoids—could help the algae bond with very narrow targets, like tumor cells, while avoiding a patient’s healthy cells.