Opto-Thermal Transient Emission Radiometry (OTTER) to image diffusion in nails in vivo

Photothermal Radiometry for Skin Research

“…Other solvents that have been studied include propylene glycol, ethylene glycol, glycerol, alcohol, decanol, butyl acetate, etc. [23,24]. OTTER can work well on both in vivo and in vitro skin samples.…”

“…By selecting detection wavelength at 9.5 µm, where water has relatively low absorption and chemical solvents have relatively high absorption, we can also measure the solvent penetration through the skin [16,17,23,24]. Figure 6 shows the OTTER results of Dimethyl sulfoxide (DMSO) penetration through skin.…”

“…Apart from in vivo and in vitro skin samples, OTTER can also work on nails, for both water content measurements and solvent penetration measurements [24,25]. Figure 7 shows the OTTER signals of human fingernail (a) and corresponding water concentration depth profiles before and after a 15 min soaking in water (b).…”

“…The nail water concentration has increased after the soaking, indicating absorbing of water through soaking, and then as nail recovered in ambient condition, the nail water concentration gradually reduced to the normal level. Figure 8 shows the solvent penetration through nail measurements, data from Reference [24]. In this experiment, three solvents were studied, glycerol, decanol, and butyl acetate.…”

Structural and component mining of nails using bioengineering techniques

“…The lower permeation of butyl acetate was attributed to its evaporation and that of decanol was due to its delipidization capacity. The permeation of glycerol was found to be maximum because of its humectant effect that led to increase in as well as maintenance of hydration [55].…”