Oral cancer has a poor five-year survival rate and has not improved much in the past two decades which is due to late diagnosis. In current clinical practice analysis of Haematoxylin Eosin stained tissue biopsy is considered as a golden standard which is rather painful and routine check is not possible. In this regard, native fluorescence spectroscopy has been considered to discriminate cancer tissue based on relative alterations in the level of tryptophan. To estimate relative variations of tryptophan at different layers of tissue fluorescence polarization gating technique has been adopted which is based on the principle that the light from the superficial layer of tissue partially retain the polarization plane of incident light as they are less scattered while light from the deeper layer is completely depolarized due to multiple scattering. Integrated intensity of tryptophan was quantified, and subsequent statistical analysis has been carried out to evaluate the diagnostic potentiality of the proposed technique. It was found that the fractional variation of tryptophan in the superficial layer to the deeper layer was found to be statistically more significant in discriminating oral cancer than cumulative tryptophan in both layers.
Fluorescence labelling is one of the significant properties for optical bioimaging and biosensing applications. The development in the field of nanotechnology has created enormous conveniences in biomedical research. The fluorescence enhancement of mammalian cell in presence of zinc nitride colloidal nanoparticle was imaged using multiphoton confocal microscope. The statistical significance in the presence and absence of nanoparticle evidenced the fluorescence intensity enhancement in the cells. In order to suppress the background signal and increase the penetration depth, the multiphoton technique is utilized by 740 nm excitation to examine the enhancement potential of Zn3N2 colloidal nanoparticles towards cell structures. Hence, we suggest that, the unique feature of inorganic nanomaterial is a promising material for probing cells for future diagnostic applications.
Urinary tract infections (UTI) are one of the frequently encountered infections in clinical practice. As there are different strains of bacteria responsible for UTI, the identification of types of bacterial is necessary to administer a proper antibiotic. Conventional staining and biochemical methods for the identification of bacteria are time-consuming and it usually leads to administer patients with broad-spectrum antibiotics which are less effective and expensive. In this regard, Multiphoton fluorescence imaging based on the distribution of NADH and FAD in several bacterial species isolated from UTI is carried out. Metabolic imaging based on fluorescence enables to analyze both biochemical distribution and their conformation. Spectral deconvolution method is used to isolate fluorescence emission from the coenzymes NADH and FAD to generate redox imaging. Further, redox imaging of bacteria was analyzed using different machine learning algorithms to improve the accuracy of classification. The results of this study revealed that the proposed technique of redox imaging was found to discriminate bacterial species. As the proposed method is both effective and less time consuming, the proposed method may be considered for real-time classification of bacterial species in the clinical setup.
Metabolic imaging of live cell may allow in understanding the molecular level changes in cells under various diseased state, including cancer. The intrinsic fluorophores, Nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are crucial for electron transfer in the oxidation-reduction reactions in the cell. Metabolic imaging based on fluorescence polarization enables to analyze both biochemical distribution and their conformation. In this study, multiphoton fluorescence polarization imaging of NADH and FAD from cancer and normal cell lines of epithelial origin were carried out. Spectral deconvolution method was adopted to isolate fluorescence emission from different coenzymes NADH and FAD. The observed heterogeneity of the multiphoton autofluorescence in live cells was used in intensity-toconcentration image conversion. The multiphoton autofluorescence exhibits anisotropy features at the cellular level, that directly indicate the presence of NADH and FAD in two differing conformation states viz; free and protein-bound. Mapping of anisotropy of cellular autofluorescence enables to probe the distribution of population fractions of free and bound forms of NADH and FAD. Further, the redox ratio between normal and cancer cell lines confirms the changes in the metabolic activities between them. These molecular-level studies demonstrate the potential of probing cellular metabolism associated with cancer, without the need for cell destruction as in the case of conventional biochemical assays.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.