Spectral and lifetime domain measurements of rat brain tumors

Haidar, Darine Abi; Leh, B.; Zanello, Marc; Siebert, R.

doi:10.1364/boe.6.001219

Cited by 40 publications

(60 citation statements)

References 33 publications

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“…In addition, by calculating the integral under the curve of the emission spectra of NADH, FAD and the porphyrins, using a Matlab program developed by our team 17 , we obtained two different ratios under 405 nm and 375 nm excitation wavelengths 11 , 18 . …”

Section: Resultsmentioning

confidence: 99%

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Optical properties, spectral, and lifetime measurements of central nervous system tumors in humans

Poulon¹,

Mehidine²,

Juchaux³

et al. 2017

Sci Rep

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A key challenge of central nervous system tumor surgery is to discriminate between brain regions infiltrated by tumor cells and surrounding healthy tissue. Although monitoring of autofluorescence could potentially be an efficient way to provide reliable information for these regions, we found little information on this subject, and thus we conducted studies of brain tissue optical properties. This particular study focuses on the different optical quantitative responses of human central nervous system tumors and their corresponding controls. Measurements were performed on different fixed human tumoral and healthy brain samples. Four groups of central nervous system tumors (glioblastoma, diffuse glioma, meningioma and metastasis) were discriminated from healthy brain and meninx control tissues. A threshold value was found for the scattering and absorption coefficient between tumoral and healthy groups. Emission Spectra of healthy tissue had a significant higher intensity than tumoral groups. The redox and optical index ratio were thenn calculated and these also showed significant discrimination. Two fluorescent molecules, NADH and porphyrins, showed distinct lifetim values among the different groups of samples. This study defines several optical indexes that can act as combinated indicators to discriminate healthy from tumoral tissues.

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Section: Resultsmentioning

confidence: 99%

“…At 375 nm, the calculated ratio has negative values because NADH is more present in brain tissues than FAD at the excitation wavelength 17 , 19 . As shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Optical properties, spectral, and lifetime measurements of central nervous system tumors in humans

Poulon¹,

Mehidine²,

Juchaux³

et al. 2017

Sci Rep

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“…It was a bi-fiber setup, one fiber to excite the fluorophore at 345nm and 405nm and the other one to collect the intensity of fluorescence and send it to the spectrometer or to the Photo Multiplier Tube for lifetime measurement analysis. This set-up has been previously published [3]. 2) Multimodal wide-field excitation imaging: one and twophotons: At the IMNC laboratory, samples were imaged using a Leica TCS SP8-FLIM microscope on PIMPA platform.…”

Section: B Set-upsmentioning

confidence: 99%

“…We could also measure SHG at 445 nm using 890 nm excitation wavelength. We developed a Matlab script to fit these different fluorophores [3], we will use it here to fit the spectra and observe the change in the mean intensity of fluorescence between fresh and fixed samples. Fig.…”

Section: A Two Photon Spectral Analysismentioning

confidence: 99%

Comparison between fresh and fixed human biopsies using spectral and lifetime measurements: Fluorescence analysis using one and two photon excitations

Poulon¹,

Zanello

Ibrahim³

et al. 2015

2015 International Conference on Advances in Biomedical Engineering (ICABME)

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International audienceThe purpose of this study is to make a comparison between the fluorescence emissions of fresh extracted human biopsies and fixed human biopsies, in order to evaluate the impact of fixation on autofluoresence signal. Our group is developing an endo-microscope to image brain tissues in-vivo, however to date, in order to validate our technology the easiest type of samples we can access are fixed samples. However, the fixation is still challenging. For that, we aim through this study to determine whether we should pursue to work on fixed samples or we should shift to work on fresh biopsies. Data were collected on spectroscopic, lifetime measurement and fluorescence imaging setups with visible and two-photon excitations wavelengths. Five fresh and five fixed samples are involved in the experiment. Endogenous fluorescence of fixed biopsies were calculated. Experimental results reveal that at 405 nm and 810 nm, the fresh samples have an intensity of fluorescence two times higher than that of fixed samples. However, for each fluorophore and each excitation wavelength, the lifetime for fresh samples is shorter than that for fixed samples. Still, further studies and investigations involving the comparison between different samples are required to strengthen our findings

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“…Optical tomography in the near IR region is now a reality, 67 and it has proven possible to use fluorescence lifetime measurements to distinguish between healthy and unhealthy cells. 68 An interesting challenge for chemists and biochemists is to be able to tag fluorophores or other radiative molecules to enable them to access specific cells or even specific regions once inside a cell. 69 The higher their specificity, the more useful these molecules will be for diagnostics and therapy.…”

Section: Photobiology: Beyond the Human Bodymentioning

confidence: 99%

What We Talk About When We Talk About Light

Forbes

2015

ACS Cent. Sci.

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UNESCO (the United Nations Educational, Scientific, and Cultural Organization) has declared 2015 the “International Year of Light and Light-Based Technologies”. In celebration of this proclamation, this Outlook provides a general history of light and its applications, from the earliest moments of the Big Bang through its present impact on all forms of life on the planet. Special emphasis is placed on fundamental advances in the generation and use of artificial light, as well as the harvesting and use of light from the Sun and other natural sources. During the past century, the role of light in the fields of physics, chemistry, and biology has expanded to include emerging fields such as environmental engineering, agriculture, materials science, and biomedicine. In this regard, future research challenges and new potential applications in these areas, in the context of “the central science”, are presented and discussed.

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Spectral and lifetime domain measurements of rat brain tumors

Cited by 40 publications

References 33 publications

Optical properties, spectral, and lifetime measurements of central nervous system tumors in humans

Optical properties, spectral, and lifetime measurements of central nervous system tumors in humans

Comparison between fresh and fixed human biopsies using spectral and lifetime measurements: Fluorescence analysis using one and two photon excitations

What We Talk About When We Talk About Light

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