Infrared Spectroscopy to Measure Collagen and Elastin in Aorta Using Multivariate Analysis

Pathological changes in extracellular matrix (ECM) occur in the context of abdominal aortic aneurysm disease. The objective of this study is to assess the capability of Fourier transform infrared spectroscopy (FTIR) to differentiate major aorta ECM components. Two partial least squares (PLS) models were developed using mixtures of matrix components in potassium bromide pellets. In the first model collagen and elastin powders were mixed in varying percentages. In the second model, pig aorta specimens were selectively degraded by enzymatic treatment of either collagen or elastin and used to prepare pellets. The results of the PLS model showed the ability of FTIR methodology for differentiation of elastin and collagen. These results lay the foundation for application of the methodology to assess the progression of AAA pathology.