As a masters student in India, Shiladitya Sengupta developed an anti-inflammatory gel thats now sold in India under the brand name Nimulid. During his doctoral studies at the University of Cambridge, he revealed how a protein that causes liver regeneration promotes blood vessel growth, and cofounded Dynamic Biosystems to turn the discovery into treatments for chronic wounds such as pressure sores. But a childs toy – several small balloons encapsulated in a bigger one – inspired what may be his greatest innovation: a nanoscale device to treat cancer. Senguptas drug delivery device, developed during his postdoc at MIT, consists of a lipid sphere about 200 nanometers wide surrounding smaller, biodegradable polymer spheres. These nanocells home in on cancers based on the unique characteristics of tumor blood vessels. The outer shells then dissolve, releasing a drug that destroys the vessels. As the cancer cells starve for oxygen, they secrete enzymes that break up the inner spheres, dispensing a standard chemotherapy agent. The nanocells have the potential both to treat tumors more effectively than existing regimes and to reduce side effects. The nanocells have proved effective in mouse models of melanoma and lung cancer. Because Sengupta designed them using polymers and drugs already approved for human use, doctors can quickly move them into clinical trials. Now an assistant professor at Harvard Medical School and Brigham and Womens Hospital, Sengupta is extending the concept to treat other diseases.