A photoacoustic study of newborn rat stratum corneum.

We have applied photoacoustic spectroscopy, a new spectroscopic technique, to the study of intact stratum corneum, a translucent membrane with high ultraviolet light scattering, and have obtained clear spectra in the 220-450 nm region. The photoacoustic technique has been used to study the effects of hydration and chemical alteration of the stratum corneum. Newborn rat stratum corneum shows marked spectral changes during the initial 60 h maturation period. These changes are attributed partly to the environmental and conformational changes occurring within the stratum corneum matrix during this time period. We also postulate the possibility of a novel molecular change within the keratin protein to account for our results.