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Biology of the Hair and Skin
Published in Randy Schueller, Perry Romanowski, Conditioning Agents for Hair and Skin, 2020
The stratum corneum is the outermost layer of the epidermis. It is responsible for protection and is affected by conditioning substances. It is formed by corneocytes which are highly resistant to degradation due to the crosslinking of a soluble protein precursor involucrin, which is acted upon by epidermal transglutaminase. The final product is a 65% insoluble cysteine-rich disulfide crosslinked protein (16). The stratum corneum presents the first barrier to percutaneous absorption, but is subject to degradation through hydration, removal through tape stripping, protein denaturation through the application of solvents, and alteration of the lipid structure (17).
Development of microstructured fish scale collagen scaffolds to manufacture a tissue-engineered oral mucosa equivalent
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Ayako Suzuki, Hiroko Kato, Takahiro Kawakami, Yoshihiro Kodama, Mayuko Shiozawa, Hiroyuki Kuwae, Keito Miwa, Emi Hoshikawa, Kenta Haga, Aki Shiomi, Atsushi Uenoyama, Issei Saitoh, Haruaki Hayasaki, Jun Mizuno, Kenji Izumi
Basal layer cells in all scaffolds, including the control flat scaffold, as well as AlloDermⓇ were shown to express α6 and β1 integrins as potential keratinocyte stem cell markers [21]. However, their immunoreactions were weaker or partially lacking in the tissue-engineered oral mucosa equivalents comprising pillar micropatterned scaffolds without 1% CS (Appendix Figures 1 a–k and 2 a–k). In contrast, while involucrin was expressed in the suprabasal cell layers of all tissue-engineered oral mucosa equivalents, it was not expressed in basal layer cells. However, a few basal layer cells expressed involucrin in the tissue-engineered oral mucosa equivalents obtained from scaffolds without 1% CS (Appendix Figure 3 a–k). A few Ki-67 immunopositive cells located in the basal layer were observed in all of the tissue-engineered oral mucosa equivalents and EVPOME (Appendix Figure 4 a–k). Moreover, p63 immunopositive cells were located in the basal layer as well as lower suprabasal layer of the tissue-engineered oral mucosa equivalents (Appendix Figure 5 a–k). In contrast, patchy expression of type IV collagen was observed at the interface between the epithelial layer and the scaffold in any of the tissue-engineered oral mucosa equivalents, although linear expression was observed in the EVPOME (Appendix Figure 6 a–k). Overall, there were few differences between the tissue-engineered oral mucosa equivalents irrespective of different microstructures and addition of CS to the fish scale collagen scaffolds, which could be caused by the loss of four initial different micropattern prototypes during manufacturing of the tissue-engineered oral mucosa equivalents.