Lina Mercedes Gonzalez

Lina Mercedes GonzalesSite-Specific Drug Delivery

Lina Mercedes Gonzalez (Hunter College, 2009, who is earning a Ph.D. in mechanical engineering at Carnegie Mellon University, is one of five CUNY students to win 2011 awards under the National Science Foundation Graduate Research Fellowship Program. It is geared to assuring the vitality and diversity of America’s scientific and engineering workforce.

Her research is part of a broad quest to deliver drugs to the specific site where they’re needed. The NSF granted her $90,000 over three years to work on a “swimmer” drug-delivery vehicle. The swimmer – measured in micrometers (hundredths of a centimeter) – is made of polydimethylsiloxane, or PDMS, a silicon-based organic polymer that’s used in everything from contact lenses to shampoos. Call it a nanobot, a tiny robot that can be injected into the body to perform medical procedures.

To work, the swimmer needs two systems – guidance and propulsion.

For guidance, Gonzalez turns to infinitesimally small magnetic particles that are naturally manufactured by magnetotactic bacteria. She extracts these particles and inserts them into the swimmer. Once the swimmer is in the body, it can be guided by external magnets.

For propulsion, she is working on a “pea whistle” system that’s roughly analogous to a basketball coach’s whistle; when it’s blown, air is forced into a chamber and exits through a slot; a “pea” bounces in the chamber, producing a warbling sound. Gonzalez said that in the swimmer, a microscale pressure tank will do the blowing and provide the propulsion. (Other researchers take a different tack to nanobot propulsion, trying to emulate flagella, the tail-like parts of many types of cells.)

Gonzalez conducts her research with Carnegie Mellon professor Philip R. LeDuc and professor William C. Messner, who are collaborating on ways to probe cellular mechanics using microfluidics, mechanatronics and control theory. Gonzalez, who expects to earn her doctorate within three years, intends to become a professor with her own lab. “The math, physics and chemistry I took at Hunter have helped a lot,” she said. She particularly credits Hunter physics professor Steven G. Greenbaum “for guiding me throughout my undergraduate career.” Among other things, he encouraged her to twice work at Caltech, where she “interacted with mechanical engineers and bioengineers, and that helped me make a decision to pursue a career as a mechanical engineer.”