Temperature-Induced Changes in Structural and Physicochemical Properties of Vernix Caseosa
Journal of Investigative Dermatology
The skin of the third trimester foetus and early newborn exhibits a complex, multifunctional, highly hydrated but viscous skin-surface biofilm called vernix caseosa. During birth, vernix caseosa undergoes a substantial change from an aqueous and warm surrounding into a gaseous and colder environment postnatally. The aim of this study was to investigate the structural and physicochemical changes in vernix caseosa which accompany physiologically relevant variations in environment parameters such
... s temperature and humidity. A remarkable difference was observed in water release and uptake properties: dehydration and rehydration processes take place 2-4 times faster at 37°C than at room temperature. The dehydration was irreversible; rehydration was only possible to a final weight of 55 % (37°C) and 46 % (room temperature) of the pre-desiccation weight. Differential scanning calorimetry showed two different overlapping phase transitions within physiological temperature range. Investigation of the lipid organization by Fourier transform infrared spectroscopy and small-angle X-ray diffraction revealed a more disordered state of lipids at 37°C than at room temperature, which might explain the faster dehydration and rehydration process at 37°C as well as the changes in thermotropic rheological behaviour. In conclusion, we demonstrated that vernix caseosa properties adjust to the fundamental change from the intrauterine to the postnatal environment.