Infrared microspectroscopic determination of collagen cross-links in articular cartilage.


Collagen forms an organized network in articular cartilage to give tensile stiffness to the tissue. Due to its long half-life, collagen is susceptible to cross-links caused by advanced glycation end-products. The current standard method for determination of cross-link concentrations in tissues is the destructive high-performance liquid chromatography (HPLC). The aim of this study was to analyze the cross-link concentrations nondestructively from standard unstained histological articular cartilage sections by using Fourier transform infrared (FTIR) microspectroscopy. Half of the bovine articular cartilage samples ( n = 27 ) were treated with threose to increase the collagen cross-linking while the other half ( n = 27 ) served as a control group. Partial least squares (PLS) regression with variable selection algorithms was used to predict the cross-link concentrations from the measured average FTIR spectra of the samples, and HPLC was used as the reference method for cross-link concentrations. The correlation coefficients between the PLS regression models and the biochemical reference values were r = 0.84 ( p < 0.001 ), r = 0.87 ( p < 0.001 ) and r = 0.92 ( p < 0.001 ) for hydroxylysyl pyridinoline (HP), lysyl pyridinoline (LP), and pentosidine (Pent) cross-links, respectively. The study demonstrated that FTIR microspectroscopy is a feasible method for investigating cross-link concentrations in articular cartilage.

DOI: 10.1117/1.JBO.22.3.035007

Cite this paper

@article{Rieppo2017InfraredMD, title={Infrared microspectroscopic determination of collagen cross-links in articular cartilage.}, author={Lassi Rieppo and Harri T. Kokkonen and Katariina A.M Kulmala and Vuokko Kovanen and Mikko J. Lammi and Juha T{\"{o}yr{\"a}s and Simo Saarakkala}, journal={Journal of biomedical optics}, year={2017}, volume={22 3}, pages={35007} }