Evaluation of optical features of fibronectin fibrils by backscattering polarization imaging

Abstract

Polarization imaging provides an effective and convenient approach for examining the structural and optical features of scattering media. The present study utilizes a backscattering polarization imaging system to evaluate and compare the polarization features of three different fibronectin (FN) samples: (1) fibronectin-free in phosphate-buffered saline (PBS) solution, (2) fibronectin protein (PFN), and (3) fibrillated fibronectin (FFN). It is shown that the three samples can be qualitatively discriminated via a simple naked-eye observation of the Mueller matrix imaging results. Furthermore, a more quantitative evaluation of the polarization properties of the three samples can be obtained from an inspection of the Mueller Matrix Transformation (MMT) parameters and Frequency Distribution Histogram (FDH) statistics for the pixel intensities of the Mueller matrix elements. The results show that the PFN and PBS samples have isotropic properties, while the FFN sample has anisotropic properties. Overall, the results confirm that the proposed backscattering polarization imaging system provides a feasible means of differentiating between different fibronectin-containing biological samples. It thus has significant potential for various biomedical diagnosis applications, including early-stage cancer detection.