TITLE:
Non-Invasive Second Harmonic Generation (SHG) in Macroscopy (MacroSHG) as Bio-Diagnosis to Image Collagen Network Organization in Extracellular Matrix
AUTHORS:
Dominique Dumas, Elisabeth Werkmeister, Sebastien Hupont, Céline Huselstein, Natalia De Isla, Marthe Rousseau, Patrick Menu, Didier Mainard
KEYWORDS:
Multiphoton Macroscopy, Second Harmonic Generation, Collagen, Extracellular Matrix
JOURNAL NAME:
Engineering,
Vol.6 No.8,
July
21,
2014
ABSTRACT: In this work, we have considered a new multimodality imaging for
macroscopy based on Second Harmonic Generation (SHG) method to monitor
invasivelessly the matrix collagen. As the triple helicoidally structure of
collagen molecules appearing as not centrosymetric, very organized and
spatially oriented, collagen fibrils give rise to a very strong SHG signal and
can be imaged without any exogenous dye. To integrate a multidimensional scale
with a large field of view (non-sliced samples), we have adapted and validated
an instrumental coupling between a two photon excitation laser and a macroscope
to collect cartography of SHG signal. We introduced an index (F-SHG) based on
decay time response measured by TCSPC for respectively Fluorescence (F) and
Second Harmonic Generation (SHG) values. For various sample where protein
collagen is the major component of extracellular matrix (vessel, skin, carotide
vessel, rat femoral head cartilage, mouse tumor, human wharton’s jelly and rat
tendon) or not (nacre), we compared the index distribution obtained with
MacroSHG. In this work, we showed for the first time that multiscale large
field imaging (Macroscopy) combined to Multimodality approaches (SHG-TCSPC)
could be an innovative and non-invasive technique to detect and identify some
biological interest molecules (collagen) in biomedical topics.