Anisotropy of bovine nasal cartilage measured by Fourier transform infrared imaging

Fourier transform infrared imaging (FTIRI) can be used to obtain the composition and structure information of sample. Here, FTIRI combined with spectral polarization analysis method was applied to investigate the fine anisotropy of bovine nasal cartilage (BNC). The upper BNC tissue was sliced into a three-dimensional (3D) block with three planes (XY, YZ, and XZ) parallel to horizontal section, forward section, and lateral section, respectively. The anisotropy of collagen fiber in BNC was represented by the absorbance of amide II (1590–1500 cm−1) at different polarization directions. It was found that collagen fiber showed little anisotropy in plane XY, XZ, and along the direction Z in plane YZ. It was more important that collagen fiber showed strong anisotropy along direction Y in plane YZ (transverse axis) of BNC, possibly including arched or wavy fiber orientation even a mixture of both in nasal septum top end. Two anisotropic deflections ranging from 600 to 930 μm and from 2680 to 2980 μm were quantitatively calculated. This study is of important significance for further understanding the physiological structure of nasal septum and provides remarkable experimental support for being a good transplant material in cartilage reshaping studies.