Karissa Tilbury, Ph.D.
University of Maine
Nonlinear optical imaging microscopies have revolutionized our ability to explore the extracellular matrix of normal and diseased states. The Tilbury Lab at the University of Maine employs two distinct non-linear imaging techniques: 2-photon fluorescence and Second Harmonic Generation (SHG). Both techniques require 2-photon interaction; however, the fundamental physical processes are unique and offer complementary information without the need of fluorescent labels. The state of cellular metabolism can be investigated at a single-cell level by comparison of the intensities from NAD(P) and FAD, two autofluorescent co-enzymes involved in cellular respiration. The extracellular matrix fibrillar collagens are specifically probed with SHG. Collectively, these techniques provide a label-free approach to specifically interrogate 3-dimensional alterations of cellular metabolism and the extracellular matrix in diseased states with micron resolution. More recently the Tilbury lab has explored diffuse optical imaging techniques to provide both tissue-level metabolism and structure. The combination of non-linear and diffuse optical techniques allows a single tissue to be interrogated across multiple size-scales. These techniques are currently being used to investigate cancer and neurological disorders to diagnose and provide early indicators of positive response to therapies.