Study of the Development of Carotid Artery Atherosclerosis upon Oxidative Stress using Infrared Spectroscopy and Scanning Electron Microscopy

Abstract

In the present study, Fourier-transform infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) were used to investigate the formation and development of carotid artery atherosclerosis. The FTIR spectra showed that with the progression of atheromatic plaque formation, the collagen changed its native structure from ɑ-helix to random coil, amyloid, and cross-links. The infrared spectra and SEM analysis of carotid arteries showed that higher than 65% of the atheromatic plaque in patients with stenosis consisted of calcium carbonate, which lies inside foam cells. However, as the stenosis progresses, these deposits of calcium phosphate become more prevalent. A thorough analysis of the SEM images highlighted that mineral deposits preferred the carboxyl groups of amino acids. The intensity and shape changes in FT-IR spectra in the region of 1200-900 cm-1 were related to elevated serum glucose and uric acid levels, the formation of advanced glycation end products (AGEs), and the involvement of free radicals during atherosclerosis.