Q&A With Bioengineer Tejal Desai
PHOTO: Tejal Desai
Prof. Tejal Desai is a leader in a field with a big name—biological microelectromechanical systems (BioMEMS)—that deals with very small items. She uses the tools of semiconductor manufacturing to make minuscule medical devices, such as a miniature artificial pancreas and scaffolding for tissue regeneration. She’s been widely recognized as one of the top young scientists in the country, having won distinctions such as the National Academy of Engineering Frontiers in Engineering Award in 2001. Desai, an IEEE member since 1997, recently spoke with IEEE Spectrum from her offices at the University of California, San Francisco.
What can semiconductor manufacturing techniques do for medicine?
From our point of view, the most exciting aspect about MEMS technology for medicine is the ability to achieve control over chemical structure, over topographical structure, over device size and scale. And to do that at a size scale that interfaces exquisitely well with the size scale of biological entities, such as cells, proteins and subcellular structures.
What kinds of products are actually in use right now?
Right now BioMEMS or microtechnology has mostly been used commercially in the diagnostic arena—things like lab-on-a-chip systems, sensors, microfluidics. These have been very useful in actually increasing the speed and accuracy as well as the sensitivity of a lot of diagnostic assays that are available. What isn’t there is sort of the therapeutic end of things. That’s mostly in the domain of academic research, where people are using these techniques for things like drug delivery, tissue engineering, and delivering therapies for disease conditions.
What are you currently working on?
We do a lot of work in diabetes, in how we can deliver cells or deliver drugs to the appropriate place and control or modulate their release. And again, it’s because we can control the size scale of our features that we can get control over the immunological response. We can control the release rate of hormones or other therapeutic products. We can use the techniques to design a device that’s going to target or adhere to certain cell types. And we couldn’t do that previously because we didn’t have this control over creating structures that were on the order of 100 microns or less.
What made you decide to move to UCSF to head up its Therapeutic Micro and Nanotechnology Laboratory?
One of the prime motivations was being able to really interface with the clinical component and bring this microengineering and nanoengineering to the basic sciences as well as the medical field, to be able to really push some of these technologies out there— rather than just doing the exercise of creating these things for engineers, actually going to the people who are going to use them in the clinic. That’s one reason why this is an exciting place to be.
How long do you think it will be before there are BioMEMS products out there that can be used for therapies?
I think we’re certainly getting there with certain drug types as well as platforms for cell cultures. So I think within the next two to five years we’ll really see some products that deal in that.
Are any companies developing your ideas?
A company, iMEDD [intelligent Microengineered Drug Delivery], is developing the diabetes platform as well as the general concept of using intelligent microengineering for drug delivery.
Are there research benefits from collaborating with industry?
I certainly think so. I think for us, the nice thing is that we have a way to scale up our ideas and actually make them so that they’re feasible. We can do very elegant, fun work in the lab, but a lot of times it’s not practical. A lot of times in working with industry, we realize we need to address issues that have to do with getting approval from the FDA, moving things forward to the clinical community, how surgeons are going to interface with a device, how patients can be compliant using something like this. There are a number of issues that we learn about, as well as some that they learn about from us. So with that going back and forth we’ve been able to push things forward at a much more rapid pace.