We developed a non-water gel product comprising HPC and PEG, reacting hydration with water. We investigated the gelation mechanism of HPC/PEG gel by means of a stress-controlled rheometer and an X-ray diffractometer. According to the results, the mechanism has two factors: entanglement of the HPC polymer chain and cross-linkage of the microcrystal domain of the HPC main chain. The HPC/PEG gel is useful as the basic material of the cosmetic plaster that causes skin surface temperature to rise and the blood stream to accelerate.

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Many studies on the preparation and application of microcapsules have been reported in the literature. We developed an innovative encapsulation technology by using silicone-resin-polypeptide as the encapsulating material The resultant microcapsule was easily prepared from silicone-resin-polypeptide. For this microcapsule not only was the extent of encapsulation as high as 90%, but the particle size could be controlled to obtain very small sizes (average particle diameter was 2.2μm) as well. Moreover, these microcapsules were resistant to relatively high shear forces and were stable over a long time period. Application in cosmetics by using micro-capsule involving UV absorbers was examined. It was possible to apply organic UV absorbers in water-rich formulations without any surfactant. This formulation demonstrated a good moisturizing and soft skin feel. The result showed this microcapsule might be widely applied in cosmetics.

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Currently, we encounter many chemical substances that can affect the skin through contact in our daily life. To keep these irritants away from us, it is very effective to create a dermal barrier film that can prevent penetration of irritants into the skin. For the purpose, we evaluated the permeation characteristics of currently available film-forming polymers, but almost all were found ineffective as barriers. Our investigation led us to fluoroalkylacrylate-polyglycolmethacrylate-alkylmethacrylate-copolymer (F-copolymer), a new acrylic copolymer. This polymer is soluble in water and can easily be incorporated into various cosmetic products. It consists of hydrophilic and lipophilic groups with fluorine units, and forms a durable, continuous film that is resistant to both water and oil upon drying. Testing on human subjects has demonstrated F-copolymer's effectiveness in countering irritation caused by water-soluble materials, including methyl paraben, lactic acid, and oil-soluble materials, like butyl paraben and methyl saricylate.

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It has been known that high amounts of ‘heat shock proteins (HSPs)’ are produced under heat and other environmental stresses in cells. Recently, it was reported that HSP could also be accumulated in some dermal cells to protect the cellular proteins from damage caused by ultraviolet radiation. Here, the authors have focused on thermophilic cyanobacteria and the heat shock treatment. Thermophilic cyanobacteria are known to thrive under extreme environmental conditions, and produce distinctively high amounts of HSP when exposed to higher temperatures. We tested cell extract from heat-shocked cyanobacterial cells on a number of skin-related biological activities and found it significantly effective, The cyanobacterial cells, originally collected from a spa as hot as 55°C, were cultivated in the laboratory at 50°C and broken by a freeze-ffacture method. The extract thus obtained had a superoxide dismutase (SOD)-like activity and inhibited lipid peroxide formation. We found that the extract obtained from the heat-shocked (at 63°C) cells showed a much stronger SOD-like activity, while the inhibitory effect on lipid peroxide formation remained almost the same, Furthermore, the SOD-like activity could withstand heat up to 70°C for as long as 1h. Most remarkably, supplementing this heat-shocked extract strongly promoted the proliferation of human dermal fibroblast culture. Extracts from the cells grown at a regular temperature (50°C) did not promote the proliferation of the fibroblasts. The heat-shocked extract was fractionated by ultrafiltration for further analysis. A fraction (molecular weight, 10000 to 30000) has shown the strongest activity so far. These results indicate that the heat-shocked cyanobacterial extract with its increased amounts of HSPs is a promising potent ingredient for anti-aging cosmetic materials.

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