Label-free imaging of collagen as a potential diagnostic marker for detection of gliomas

The collagen in glioma is changed due to remodeling of the extracellular matrix during the malignant process and plays an important role in the progression of human gliomas. In this paper, multiphoton microscopy (MPM) based on twophoton excited fluorescence (TPEF) and second harmonic generation (SHG) was introduced to image the changes of collagen in normal human brain and gliomas. What's more, together with the image analysis, the collagen content was quantitatively measured. It was found that in gliomas the collagen content significantly increased compared to normal brain tissue. These results suggest that MPM has the capability to provide collagen signature as a potential diagnostic marker for detection of gliomas.