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<sup>-1</sup> 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.

Infrared Spectral Digital Imaging and Bone Cancer Diagnostic

“…confirming the suggestion that oxidative modification of proteins by ROS (reactive oxygen species) took place upon cancer development [47][48][49][50]. The intensity of this particular band is also related to the presence of inflammation.…”

The Effect of Irradiation on the Skin upon Breast Cancer Radiotherapy Studied by FTIR Spectroscopy

“…In the next important spectral region between 3000-2850 cm -1 are shown the stretching vibration bands of asymmetric and symmetric vibrations of methyl (vas,sCH3) and methylene (vas,sCH2) groups mainly from membrane lipids and phospholipids [28][29][30][31][32][33][34][35]. After skin irradiation, the asymmetric and symmetric vibrations of methyl (vas,sCH3) almost disappeared and the corresponding intensities of methylene stretching vibration bands (vas,sCH2) increased in intensity, concerning the increasing lipophilicity of the membrane environment [26-35, 40, 41].…”

“…Fourier Transform Infrared (FT-IR) spectroscopy is an appropriate method to study the changes induced by irradiation on skin tissues. FT-IR spectroscopy is a non-invasive physicochemical method, that is reproducible, extremely rapid, and does not require any special treatment or labeling of the samples as in histopathology [28][29][30][31][32][33][34][35]. The method is based on the interactions of infrared radiation taking place within the matter and the obtained spectrum contains all the vibrations of the molecules present in a sample, which may be simple as a single cell or more complicated, such as a tissue and body liquid providing information on all components simultaneously [28][29][30][31][32][33][34][35] of complex shapes of groups, such as NH, NHCO, COOH, CH3, CH2, PO2-, etc.…”

“…of biomolecules in cells and tissues simplify the analysis. This makes FT-IR spectroscopy an extremely valuable tool for lipid, protein, DNA, and membrane structural determination studies in the pre-diagnosis and diagnosis of diseases [32][33][34][35]. In this research paper, to simulate the effects of ionizing radiation on the skin during RT, the skin was irradiated ex-vivo with γ-60 Co rays.…”