Thermally stimulated current changes of irradiated skin

Abstract

Radiation effects on collagen and skin have been characterized by means of thermally stimulated current (TSC) spectroscopy. X-rays, [3-rays and UV radiation have similar effects on the molecular mobility of dermal collagen and skin. They induce a decrease of intra and intermolecular mobility. The restriction of molecular movement can be explained by an increase of collagen cross-links.

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

“…In this case, skin biopsies are not characterized in their native state and most of the information associated with hydric organization is lost. Nevertheless, studies in the dehydrated state have previously shown their ability to provide markers of the intrinsic dynamics of the constitutive proteins of extracellular matrix such as cardiovascular tissues and rat skin . So it was essential to check this feasibility on freeze dried human skin.…”

“…Nevertheless, studies in the dehydrated state have previously shown their ability to provide markers of the intrinsic dynamics of the constitutive proteins of extracellular matrix such as cardiovascular tissues 25 and rat skin. 26 So it was essential to check this feasibility on freeze dried human skin. In Figure 6 are reported the TSC curves of a freeze-dried skin biopsy in the sun-protected zone of a young subject corresponding to an initial poling of 400 Vmm −1 at 25°C and 150°C.…”

“…Main graph: TSC curve recorded after an initial poling of 400 Vmm −1 at 150°C F I G U R E 7 Mean temperature maxima and surface normalized intensities of the β mode for the four series of freeze-dried biopsies radiation. 26 The decrease in the localized amplitude can be connected to:…”

“…35 The amplitude of the α relaxation mode tends to diminish with the cumulative effect of aging and UVs; such a behavior has been already observed for collagen extracted from rat skin and for rat skin exposed to ionizing radiations. 26 Both the increase in glycation products with chronological aging and the decrease in collagen fraction with photo-aging could explain the evolution of this indicator of the chain mobility of dermis structural proteins at the ten nanometers scale.…”

“…Due to its very low equivalent frequency, the Thermostimulated currents technique (TSC) allows to decouple relaxations modes in proteins and tissues from the conductivity that often hides the relaxation processes, and it is appropriate to scan the molecular mobility of collagen and elastin at the nanometric and mesocopic scales. In peculiar, it has been successfully used to identify localized and delocalized motions in keratin, elastin, aortic tissues and irradiated rat skin and to help the knowledge of the different organization levels in the pre‐fibrillar state of elastin‐like peptides …”