PHOTO: Tejal Desai
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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.
“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.”
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.