Impact of Aging and Pathologies on Human Oral Mucosa: Preliminary Investigation of Biophysical Markers from Thermal and Vibrational Analyses

This study first examines the potential of using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) to extract molecular and organizational markers from human oral mucosa. These indicators are then examined in relation to age and pathophysiological conditions. Oral mucosa biopsies were collected from 38 patients during surgical procedures and analyzed using FTIR and DSC-validated protocols. The patients were divided into two age groups, namely 20-40 and 70-90 years. Vibrational markers of the lamina propria and epithelium, including lipid-to-protein and collagen-to-protein ratios and lipid order, were extracted from the FTIR spectra of both layers. Hydration levels and collagen thermal stability were determined from DSC thermograms of the entire biopsy. The preliminary findings of this study, which will require further validation in a larger patient cohort, indicate a significant decrease in bound water content and collagen denaturation temperature in the older population. This suggests that oral mucosa undergoes structural dehydration and collagen destabilization with age. Further comparisons within the older group revealed links between biophysical markers of the oral mucosa and chronic or local pathologies. Patients with cardiovascular diseases exhibit altered collagen organization, while patients with diabetes display differences in the lipid-to-protein ratio and the order of lipid chains in the epithelium. Gingivitis is associated with variations in the collagen-to-protein ratio, which supports the role of inflammation in extracellular matrix remodeling.