While many recognize the need for future biomedical research projects to be conducted by interdisciplinary teams, our conventional science and engineering educational programs do little to prepare students to contribute in such environments. The goal of this project was to prepare students from engineering and the physical sciences to work at the interfaces between those disciplines and biology in areas such as bionanotechnology. We devised four programs to meet this challenge: a summer academy for high school students, freshman seminars in bionanotechnology, a biology course for physical scientists and engineers, and a summer internship program for engineers and physicists.
The high school summer academy targeted students at the predominantly Hispanic Science Academy of South Texas as well as inner-city schools in Houston. Students were engaged in interdisciplinary research early on, paired with graduate students conducting research in bionanotechnology for hands-on exposure to the research environment, and attended lectures and field trips. The goal of this program was to increase the pipeline of qualified students pursuing careers in science and engineering.
The freshmen seminars in bionanotechnology were held for both science and nonscience majors at Rice University. The courses were taught by postdoctoral fellows to allow very small class sizes for interactive discussions, with the goal of sparking interest in interdisciplinary science topics early in the educational process and elucidating the linkages between disciplines. The postdoctoral fellows involved in this program were engaged in a teacher training program before and during their time in the classroom.
A single-semester accelerated course taught key concepts of modern cell and molecular biology to undergraduates at Rice University majoring in engineering, computer science, mathematics, physics, or chemistry. The goal was to enable students with expertise in nanotechnology or related technological disciplines to apply their knowledge to biological or medical problems. The course was taught using numerous technology case studies to provide examples of bionanotechnology and help these students understand how concepts in their field of study can be applied within the biological sciences.
The summer internship program for undergraduates majoring in engineering and the physical sciences, especially women and underrepresented minorities, consisted of a three-week intensive biology lecture and laboratory course teaching cell culture, basic molecular biology, and protein biochemistry. The course was intended to provide students arriving with little knowledge of biology with a background and laboratory skill base sufficient to allow them to start to participate as part of a team conducting interdisciplinary research in bionanotechnology. The course was followed by eight weeks of bionanotechnology research within laboratories at Rice University. This program recruited students nationwide.
Our ever-improving understanding of the progression of most pathologies has come primarily from imaging and histologic studies with fundamental resolution limits at the micron scale and above. At the same time, molecular studies, generally at the sub-nanometer scale, have elucidated many key biochemical pathways. I believe that major advances in both diagnostics and therapeutics can be achieved by working at the length scale that bridges these domains—the nanoscale. Of particular interest to me is the diagnosis and treatment of cancer. Nanotechnology may offer new options for earlier and more accurate detection of cancer as well as more effective therapies.
One of the projects in my laboratory involves development of a cancer therapy based on a new class of nanomaterials called gold nanoshells that can be targeted to tumor sites and that rapidly and locally heat upon exposure to near infrared light. Nanoshells are a new type of nanoparticle composed of a dielectric (for instance, silica) core coated with an ultrathin metallic (for instance, gold) layer. Gold nanoshells possess physical properties similar to gold colloid, in particular, a strong optical absorption due to the collective electronic response of the metal to light. The optical absorption of gold colloid yields a brilliant red color that has been of considerable utility in consumer-related medical products, such as home pregnancy tests. In contrast, the optical response of gold nanoshells depends dramatically on the relative size of the nanoparticle core and the thickness of the gold shell. By varying the relative core and shell dimensions, the color of gold nanoshells can be varied across a broad range of the optical spectrum that spans the visible and the most of the infrared spectral regions. Of particular interest is the ability to design nanoshells with extinction in the near infrared (600-900 nm) where penetration of light through tissue is maximal. Gold nanoshells can be made to either preferentially absorb or scatter light at their plasmon resonance by varying the size of the particle relative to the wavelength of the light at their optical resonance, enabling both therapeutic (photothermal ablation) and diagnostic (near infrared imaging) applications.
In another project, I have recently started to develop nanoparticle-based strategies for in vivo characterization of the molecular hallmarks of tumor invasiveness and metastatic potential by monitoring the activity of certain proteolytic enzymes like MMP2 within a tissue. We have fabricated nanoparticles that consist of a fluorescent quantum dot core nanoparticle, conjugated to small gold colloid particles via peptide linkers that are degradation substrates for MMP2 (or other proteolytic enzymes of interest). When the gold particles are close to the surface of the quantum dot (within a few nanometers), the fluorescence is largely quenched. Once the peptide linker is cleaved, the gold colloid can separate from the quantum dot, resulting in a dramatic increase in fluorescence that can be imaged in vivo. Further, it should be possible to simultaneously monitor the activity of multiple proteolytic enzymes simply by forming conjugates of different colored quantum dots (including multiple NIR wavelengths) and gold, each with a peptide sequence targeted for degradation by a different protease. This could possibly allow very detailed profiling of metastatic potential, thus guiding the physician's choice of treatment strategies. Drugs can also be attached to the proteolytically-sensitive peptides such that drug release from the nanoparticles is induced within the tumor sites via increased proteolytic activity.
Last updated September 2006