In-vivo NIR autofluorescence imaging of rat mammary tumors
ABSTRACT We investigate in vivo detection of mammary tumors in a rat model using autofluorescence imaging in the red and far-red spectral regions. The objective was to explore this method for non-invasive detection of malignant tumors and correlation between autofluorescence properties of tumors and their pathologic status. Eighteen tumor-bearing rats, bearing eight benign and seventeen malignant tumors were imaged. Autofluorescence images were acquired using spectral windows centered at 700-nm, 750-nm and 800-nm under laser excitation at 632.8-nm and 670- nm. Intensity in the autofluorescence images of malignant tumors under 670-nm excitation was higher than that of the adjacent normal tissue. whereas intensity of benign tumors was lower compared to normal tissue.
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ABSTRACT: Fluorescence imaging in diffusive media locates tumors tagged by injected fluorescent markers in NIR wave-lengths. For deep embedded markers, natural autofluorescence of tissues comes to be a limiting factor to tumor detection and accurate FDOT reconstructions. A spectroscopic approach coupled with Non-negative Matrix Factorization source separation method is explored to discriminate fluorescence sources according to their fluorescence spectra and remove unwanted autofluorescence. We successfully removed autofluorescence from acquisitions on living mice with a single subcutaneous tumor or two capillary tubes inserted at different depths.Proceedings of SPIE - The International Society for Optical Engineering 02/2011; DOI:10.1117/12.874594 · 0.20 Impact Factor
Article: Two-photon imaging of stem cells[Show abstract] [Hide abstract]
ABSTRACT: A variety of human and animal stem cells (rat and human adult pancreatic stem cells, salivary gland stem cells, dental pulpa stem cells) have been investigated by femtosecond laser 5D two-photon microscopy. Autofluorescence and second harmonic generation have been imaged with submicron spatial resolution, 270 ps temporal resolution, and 10 nm spectral resolution. In particular, NADH and flavoprotein fluorescence was detected in stem cells. Major emission peaks at 460nm and 530nm with typical mean fluorescence lifetimes of 1.8 ns and 2.0 ns, respectively, were measured using time-correlated single photon counting and spectral imaging. Differentiated stem cells produced the extracellular matrix protein collagen which was detected by SHG signals at 435 nm.Proceedings of SPIE - The International Society for Optical Engineering 03/2008; DOI:10.1117/12.762734 · 0.20 Impact Factor
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ABSTRACT: Although there are many articles focused on in vivo or ex vivo Raman analysis for cancer diagnosis, to the best of our knowledge its potential to predict the aggressiveness of tumor has not been fully explored yet. In this work Raman spectra in the finger print region of ex vivo breast tissues of both healthy mice (normal) and mice with induced mammary gland tumors (abnormal) were measured and associated to matrix metalloproteinase-19 (MMP-19) immunohistochemical exam. It was possible to verify that normal breast, benign lesions, and adenocarcinomas spectra, including the subtypes (cribriform, papillary and solid) could have their aggressiveness diagnosed by vibrational Raman bands. By using MMP- 19 exam it was possible to classify the samples by malignant graduation in accordance to the classification results of Principal Component Analysis (PCA). The spectra NM /MH were classified correctly in 100% of cases; CA/CPA group had 60 % of spectra correctly classified and for PA/AS 54% of the spectra were correctly classified.Proceedings of SPIE - The International Society for Optical Engineering 02/2012; DOI:10.1117/12.909159 · 0.20 Impact Factor