Nonlinear label free optical imaging for morpho-functional cellular and tissue diagnosis.
imaging lies in the heart of patient care. In fact, cyto-histopathological diagnostic
imaging, through the microscopic examination of cellular and tissue samples, is
considered an essential component of clinical care as a diagnostic and pathognomonic
aid. Traditional pathology is inherently invasive as it de facto requires the removal of
the biological sample from the human b... read moreody. Moreover, the necessary incorporation of
processing steps, including those with fixatives and staining agents, not only delays
the diagnostic outcome, but also introduces biochemical artifacts such as loss of tissue
components, tissue shrinkage and constituent cross-linking. It is thus evident that
standard cyto-histopathological evaluation, despite its undisputable contributions to
patient care, is unable to study the dynamic nature of physiological and
pathophysiological processes in an unperturbed, real-time, in situ manner. Novel optical
imaging modalities offer the unique opportunity to obviate the need for tissue excision
and enable non-destructive, in-vivo morpho-functional analysis. Nonlinear optical
imaging (NLO) embodies an assortment of powerful microscopy techniques that generate
high-contrast, high-resolution, three-dimensional imaging by exploiting nonlinear,
high-order light-matter processes. The application potential of NLO multi-photon
microscopy (MPM), through two-photon excited fluorescence (TPEF), fluorescence Lifetime
Microscopy (FLIM) and second harmonic generation (SHG) imaging, represents the emphasis
of this dissertation. Numerous applications are explored in the context of
characterizing intracellular or extracellular morpho-functional changes for diagnostic,
monitoring and treatment related biomedical applications in a noninvasive, label-free,
unperturbed manner in situ. These cover complex and heterogeneous spatiotemporal
biological systems in vitro, ex vivo and in vivo and ultimately lead to the diagnostic
evaluation of all levels of cancerous progression (pre-cancer, invading cancer,
metastasis) in human tissues. Ultimately this dissertation aims to highlight that the
knowledge gained from elucidating the morpho-functional interplay of tissue homeostasis
and disease progression through noninvasive NLO multi-photon imaging, may play a
transformative role in the pathophysiological mechanistic understanding of tissue
biology and in the development of improved diagnostic systems and therapeutic regimens
in a broad range of biomedical and clinical
Thesis (Ph.D.)--Tufts University, 2018.
Submitted to the Dept. of Biomedical Engineering.
Advisor: Irene Georgakoudi.
Committee: Bruce Tromberg, Sergio Fantini, and Thomas Schnelldorfer.
Keywords: Biomedical engineering, and Optics.read less