Seminar on
Modern Optics and Spectroscopy


Tom Foster, University of Rochester

Optical signatures of response to photodynamic therapy

December 5 , 2006

12:00 noon - 1:00 p.m. Grier Room 34-401


Abstract:

Photodynamic therapy (PDT) is a photochemical strategy to treat local diseases including a variety of cancers, pre-cancers, microbial infections, and macular degeneration.  Because the therapy is initiated by light, it lends itself naturally to optical monitoring.  We are currently investigating a number of optical spectroscopic and imaging approaches to monitoring cell and tissue responses to PDT.  In a clinical study at nearby Roswell Park Cancer Institute, we are monitoring the fluorescence photobleaching of protoporphyrin IX and photoproduct accumulation in the skin of patients treated for superficial basal cell carcinoma.  The results are guiding the choice of optimal treatment parameters for this patient population.  In pre-clinical cancer models, we are interested in the use of fluorescence imaging to evaluate the microscopic heterogeneity of photosensitizer distribution in vivo and of gene expression in response to photodynamic insult.  In cell systems, light scattering is very sensitive to PDT-mediated perturbations of specific organelle populations.  In particular, angle-resolved light scattering detects mitochondrial swelling and disruption of lysosomes.  PDT photosensitizers have also proven to be useful in more basic biophysical studies of the refractive indices of intracellular organelles.

TUESDAYS, 12:00-1:00, GRIER ROOM (34-401)
Refreshments served following the seminar

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Co-sponsored by the George R. Harrison Spectroscopy Laboratory,
the Department of Electrical Engineering and Computer Science and
the School of Science, Massachusetts Institute of Technology.