Identification of ageing biomarkers in human dermis biopsies by thermal analysis (DSC) combined with Fourier transform infrared spectroscopy (FTIR/ATR)

Abstract

DSC and FTIR are well-suited techniques to characterize human skin, giving accurate results with a high reproducibility. The combination of these techniques is useful for a better understanding of human skin modifications with intrinsic and extrinsic ageing.

Raman characterization of human skin aging

“…The dermis is a connective tissue containing high levels of extracellular matrix proteins, mainly collagens, elastin, and glycosaminoglycan (GAG). Collagen I, which represents around 90% of collagen fibrils, decreases with aging, due to a lower synthesis level and a higher matrix degradation . Collagen degradation can be caused either by direct UV absorption or through matrix metalloproteinase activities .…”

“…Collagen degradation can be caused either by direct UV absorption or through matrix metalloproteinase activities . Differences between photoaging and chronological aging have been observed on collagen fibers’ structure: These fibers are thickened and fragmented on photo‐exposed areas, while they appear more stable on skin subjected only to chronological aging . Another feature of photoaging is the increase of GAG proportion in the dermis …”

“…Collagen I, which represents around 90% of collagen fibrils, decreases with aging, due to a lower synthesis level and a higher matrix degradation. [2][3][4] Collagen degradation can be caused either by direct UV absorption or through matrix metalloproteinase activities. 1 Differences between photoaging and chronological aging have been observed on collagen fibers' structure: These fibers are thickened and fragmented on photo-exposed areas, 5 while they appear more stable on skin subjected only to chronological aging.…”

“…10 In young skin, water is essentially observed in bounded form, 13 while in photo aged skin the water-protein interactions decrease. 2,14 This phenomenon leads to an alteration of the overall protein stability. 5 Moreover, in skin aging, the free water content of the dermis increases, 2 principally in the papillary dermis.…”

Chain dynamics of human dermis by Thermostimulated currents: A tool for new markers of aging

“…3,6,7 Nevertheless, due to multifactorial and slowness of the aging processes, that leads to subtle changes of biological function (including biochemical, morphological, physical aspects) complementary studies on aging are still of interest. [8][9][10][11] In a previous work, 12 we showed that Differential Scanning Calorimetry (DSC) was a powerful technique to evaluate the hydric…”