Distinction of dermal conditions related to collagen state using THz spectroscopy

The absorption spectra of the dermis and epidermis were measured in a terahertz band from 0.2 to 2 THz. The absorption magnitude of the dermis was higher than that of the epidermis owing to the inclusion of collagen fibers. The absorption of the dermis decreased upon heating at high temperature, and this tendency was similar to that of a collagen sheet. This finding suggests that the condition of the dermis can be distinguished on the basis of the absorption property regarding collagen. Furthermore, we found that the collagen state affected the growth rate of fibroblasts grown on the collagen. We considered that the absorption property dependence on the collagen state also included information on cell activity for tissue regeneration.