The large variability in key tissue optical properties, such as refractive index, scattering coefficient, and absorption coefficient, in biological media has been of major interest for achieving reliable optical diagnoses of disease and for quantifying specific features in the tissues. One of the key advantages of the optical imaging is its minimal invasiveness, which allows for safe practices and enables progressive in vivo optical diagnostics and treatment. In addition, optical imaging modalities are complementary to conventional radiation imaging techniques as a broad range of optical techniques are readily available to the study of biochemical processes in a complex biological environment. However, there are shortcomings in reference tissue optical properties and validated biomarker signatures, making it difficult to enable quantitative studies of the disease specific biochemical processes.
This project involves research activities to (1) develop, evaluate, and apply quantitative optical imaging technologies to correlate optical contrast in field-imaging data (e.g., surgical scenes and biomarker molecular signatures in vivo), using label-free imaging techniques based on auto-fluorescence, absorption, scattering, and vibrational characteristics with statistics-based image analysis techniques; (2) manipulate and evaluate optical contrast of tissue-mimicking phantoms and physiologically relevant in vitro 3D cell cultures with controlled expressions of endogenous biomarkers towards the development of quantitative label-free hyperspectral imaging in the clinic and optical diagnosis and therapy such as drug delivery and targeting for photodynamic therapy and hyperthermia treatment; (3) develop optical measurement techniques and standards for quantitative characterization of biochemical properties (e.g. affinity, specificity, diffusivity, etc.) of endogenous molecular probes (e.g, oxy- and deoxy-hemoglobin, cytochrome-C, lipofuscin, etc.) involving tumor and infectious diseases; and (4) develop, evaluate, and model label-free contrast imaging in emerging optical technologies including quantitative Doppler imaging in optical coherence tomography, hyperspectral confocal microscopy, hyperspectral dark-field scatter imaging, quantitative oximetric imaging, photoacoustic imaging, and near-infrared auto-fluorescence imaging.
Equipment and facilities available for this project include the following: (1) Leica SP5X hyperspectral confocal microscopy with a white-light pulsed laser and a Ti:Sapphire laser, spectrograph-coupled photon-counting detectors, and single Pico-quant photon counting correlation spectroscopy; (2) hyperspectral dark-field imaging station to enable spectroscopic scatter imaging; (3) aspectral-domain optical coherence tomography with open source code signal processing algorithms; (4) a variety of computational and modeling software packages including Finite-Difference Time-Domain (FDTD) simulation software for electromagnetic field calculation, COMSOL Multiphysics numerical simulation package, Gaussian electronic structure calculation program, and IDL/ENVI software for the analysis of hyperspectral image data; (5) a BSL2 laboratory with a 3D printer for 3D cell culture and a variety of analytical chemistry equipment including fluorometer, UV-VIS spectrometer, circular dichroism spectrometer, etc.
Biophotonics; Photonics; Optical imaging; Medical imaging; Label-free imaging; Tissue-mimicking phantom, 3D cell culture; Hyperspectral imaging;