Synthesis and characterization of high-quality skin-cooling sheets containing thermosensitive poly(N-isopropylacrylamid).

Poly(N-isopropylacrylamide) (PNIPAAm) is the most popular thermosensitive polymer, and exhibits a low critical solution temperature of approximately 32°C. This study aimed to examine the usefulness of new cooling sheets, which are manufactured using a thermosensitive poly(N-isopropylacrylamide) (PNIPAAm) material. We prepared cooling-hydrogel sheets containing PNIPAAm (PNIPAAm sheet). We measured the skin temperature on the arms of the subjects using a thermograph and compared the usefulness of the PNIPAAm sheet and a control cooling-hydrogel sheet that did not contain the PNIPAAm mixture. Thermographic measurements obtained 40 min after the treatment with the cooling sheets showed the skin temperature of the subjects treated with the 3.% (w/w) PNIPAAm sheets to be significantly lower than that of the subjects treated with the control cooling-hydrogel sheet (p < 0.005). Compared with the control sheet, the cooling effect of the new PNIPAAm sheet also persisted for a longer duration (up to 100 min). The PNIPAAm sheets exhibited excellent cooling effects. This sheet may therefore be useful for lowering the body temperature of patients with high-grade fever, such as fever due to influenza infection.

The usefulness of sebum check film for measuring the secretion of sebum.

Patients with atopic dermatitis (AD) often present with dry skin, and the reduced secretion of sebum may be responsible for the impaired skin barrier function. A sebum check film enables the patient to self-evaluate the skin sebum content. This study compared the sebum check film with a sebumeter. The skin sebum content of the forehead was measured using a sebum check film and a sebumeter. The findings of the sebum content of healthy controls showed that the sebum dot fields on the sebum check film were significantly correlated with the sebum content measured using the sebumeter (r = 0.774, p < 0.001). In addition, the sebum fields on the sebum check film of AD patients (n = 26) were significantly less than those on the sebum check film of the controls (n = 30; p < 0.05). Furthermore, the analysis of the sebum fields on the sebum check film of the AD patients was significantly correlated with their sebum content findings that were obtained using a sebumeter (r = 0.592, p < 0.01). These findings indicate that the sebum check film is easy to use for measuring the sebum secretion and is suitable for self-checking the sebum contents by AD patients for daily skin care.