Highlight
Measuring Mechanical Forces Across Sheets of Living Cells
Achievement/Results
IGERT Fellow Jessica Zimberlin and Professor Alfred Crosby (Dept. of Polymer Science & Engineering) have developed a new measurement technique that epitomizes the strength of interdisciplinary research efforts fostered by the UMass IGERT Program in Nanotechnology Innovation. The fundamental goal of Ms. Zimberlin’s research is understanding the mechanics related to the early stages of tissue formation of biological cells.
Over the past 20 years or more, significant advances in the fields of biology and tissue engineering have clearly demonstrated the importance of mechanical properties in guiding the development of healthy cells, but this work has largely focused on single, isolated cellular responses. To date, the ability to measure the strains and stresses exerted by confluent cell sheets, which depend strongly on cell-cell interactions, has been limited by a lack of sensitive, simple measurement techniques that do not severely alter native cellular processes.
Ms. Zimberlin and Prof. Crosby have developed a novel polymer surface that combines micro-scale patterning and the controlled buckling of nanoscale polymer films to measure these stress-strain responses for confluent cell sheets and are developing quantitative models to relate these measurements to the cytoskeletal components and associated biological processes. The development of these models and the design of future experiments builds upon a very strong collaboration with Professor Patricia Wadsworth from the Biology Department at UMass. In addition to using these nanofabricated surfaces to learn about the details of cell sheet mechanics, they also offer novel routes to advanced applications. For example, as the surfaces buckle due to cellular stresses, an array of microlenses is formed on the materials surface. These microlenses have been demonstrated to focus light and images, and truly represent a “living” technology. This imaging ability combined with their quantitative measurement of tissue mechanics makes these surfaces extremely attractive for a range of technologies, from personalized chemical and biological sensors to high-throughput screening devices for different cell-based ailments.
The first manuscript describing this technique is currently under review for publication. A University of Massachusetts public technology disclosure listing Jessica Zimberlin as co-inventor is at http://amherst.cvip-umass.net/users/pdfs/NCTDUMA08-02.pdf.
Address Goals
This accomplishment highlights interdisciplinary research involving a fruitful collaboration between two distinguished UMass Amherst research teams led by Prof. Crosby of Polymer Science and Engineering and by Prof. Wadsworth of Biology. Prof. Crosby’s research group has well-established expertise in the study of adhesion and friction of patterned interfaces, properties of polymer/nanoparticle composites, and mechanics of biomaterial structures, as well as in the development of unique classes of materials and material interfacial/surface structures useful for various commercial applications. Prof. Wadsworth’s research group specializes in the study of cell division, including both the assembly of the mitotic spindle and cytokinesis. IGERT Trainee Jessica Zimberlin has bridged the two disciplines in her research, in the process generating five conference papers or posters (including posters at a Gordon Research Conference in 2007), one submitted journal article, and co-inventorship with Profs. Crosby and Wadsworth on a provisional patent application.
These are notable accomplishments considering that the domains of polymer science and engineering (artificial materials) and biology (living tissues) often don’t share much in common. With regard to the learning dimension of this experience, it should be noted that Jessica has sought out interesting learning opportunities for her research, doing a three-month summer research project on cell sheet engineering at Tokyo Women’s Medical University in 2006 just prior to becoming an IGERT Fellow. She spoke on the topic of Living Microlenses at the Young Women in Science summer program in 2007 at Simon’s Rock College, and has been instrumental in organizing our IGERT trainees in group settings for serious discussion and fun activities. We view Jessica’s project as an outstanding example of the interdisciplinary learning/research experience that the IGERT program seeks to engender for all participants.
