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Lifechips trainee Isaac Janson's poster paper
Achievement/Results
NSF funded IGERT-Lifechips student Isaac Janson from the department of Chemical Engineering and Materials Science participated in the 2nd International Symposium on Lifechips 09 that took place at University of California, Irvine in January 9th and 10th of 2009. His poster was one of the many shown at the symposium. His poster title is “Interactions between osteogenic cells and nano-featured poly (methylmethcrylate) substrates and the potential role of surface wettability.” He worked on this paper with his advisor and other faculty members including Yen Peng Wong, Chirag B. Khatiwala, Andrew J. Putnam, and Albert F. Yee from UC Irvine.
Isaac Janson discusses his poster paper that they have explored an alternative approach to controlling the wetting characteristics of the cell-material interface by introducing well-defined surface topographies at the nanoscale. With this approach, the chemical and physical properties of material surfaces are linked, such that the conformations and biological activities of extracellular matrix proteins can change dependent on surface interactions. Isaac and his advisors continued to explore the approach further by using a model system in which pre-osteoblastic cells were seeded on smooth and nano-featured poly (methylmethacrylate) PMMA films.
Isaac’s methods include using nanoimprint lithographic techniques to imprint three sets of PMMA films with gratings. They designed the substrates as smooth, G90, or G300 based on their topographical features. AFM was used to characterize the topographical features of the substrates. Isaac also used four metrics to determine topographical differences. The surface roughness was also determined for comparisons between lined and smooth film surfaces. Also, the static contact angle measurements were made on each set of PMMA substrates.
Isaac discusses in his conclusion that the osteogenic cells seeded on G300 differentiated and produced more bone in comparison to the other substrates. The G300 substrates were more hydrophilic and also had a greater line height in comparison to G90 substrates. Their results indicate that hydrophilicity and line height may be coupled. Previously, little explanation has been given; line geometry that is hydrophilic may induce protein alignment, exposing adhesion sites in such a way that cells attach via specific integrins. Hydrophilic surface chemistries produce a similar result. For future work, Isaac will look into decoupling the line height and wettability and protein conformation changes and subsequent influences on integrin-mediated cell adhesion downstream cell function will also be investigated.
Address Goals
Lifechips trainee Isaac Janson’s involvement in conferences reflects Lifechips program’s goal of fostering for disciplinary research by supporting and providing the students with opportunities and platforms such as the symposium, where they can share and discuss more about their work. The networking is very important also because through talking and getting to know more about one another’s work, there are chances for research collaborations.
