||ADVANCED SPECTROSCOPIC METHODS FOR THE QUANTITATIVE ANALYSIS OF SYNTHETIC BIOMATERIALS AND BIOGENIC TISSUE
This doctoral thesis is aimed at describing new developments of Raman spectroscopy in the field of biomedical science, specifically oriented in the study of synthetic man-made biomaterials and natural biogenic materials. In this work, it will be highlighted the high versatility of Confocal Raman microprobe spectroscopy in a number of different inorganic and organic sample as a demonstration of newly developed computational algorithms, also when combined with different spectroscopic analyses such as Cathodoluminescence and X-Ray diffraction. A spectroscopic study on the importance of oxygen vacancy in a synthetic biomaterial as zirconia will show the feasibility of the mentioned techniques in detecting polymorphic transformation. This will be directly applied to the analyses of artificial hip joints, where materials degradation during in-vitro testing or during in-vivo service could be observable. Application of Raman techniques will also be shown with the purpose of a reliable screening of human biogenic materials like as teeth and skin, in which their composite structures are made of combinations of different molecules. In particular, new Raman algorithms have been developed for practical dental research and forensic analyses. The Raman tensor element method has quantitatively been applied to the analysis of local crystallographic orientation in both single-crystal hydroxyapatite and human teeth to look into the efficacy of vibrational assessments in locating chemical and crystallographic fingerprints of dental caries and non-cavitated carious lesions. Clear spectroscopic features could directly be translated in terms of a rigorous and quantitative classification of crystallographic and chemical characteristics of diseased enamel structures. Finally, the Raman microprobe spectrometry has been applied to study the biophysical links between vibrational characteristics and the chemical changes associated with aging in human skin. Our spectroscopic approach yields clear compositional information of protein folding and crystallization of lipid structures, which can lead to a precise identification of age from infants to adults.