Biomechanical behavior of human stratum corneum : impact of treatments on SC components
Abstract/Contents
- Abstract
- The stratum corneum (SC) is a remarkable biocomposite thin-film material. As the outermost layer of human skin, it serves as our primary protection against environmental insults such as bacterial infection, UV damage, temperature changes, and chemical exposure. To accomplish this task, it must be mechanically robust yet flexible; provide a barrier to water loss while maintaining its own moisture balance; and act as an interface through which we can perceive the outside world while not exposing any living tissue to harm. The SC fulfills these daunting duties thanks to its complex structure, which takes advantage of several structural elements operating at various scales to provide the wide array of biomechanical properties and behaviors necessary for its function. Among the most important of these are the keratin structural fibers which make up the bulk of the SC and provide rigidity and strength to the tissue; the intercellular lipid bilayers which comprise the primary barrier to water transport through the skin; and finally the corneodesmosome binding protein complexes, which physically hold the individual corneocyte skin cells together and which are critical for both the mechanical integrity and proper shedding of human skin. In this work the impact of various topical treatments on each of these three SC components is examined using biomechanical thin-film testing methodologies. First, the impact of lipid and natural moisturizing factors (NMFs) on the barrier function of the SC is studied. By extracting these components from the tissue, changes to the drying behavior of the SC is induced. In particular, lipid damage is found to increase both the magnitude and rate at which mechanical stresses develop in the tissue during drying. These changes are found to be linear with the fraction of lipids extracted from the skin. Next, two keratin dispersing compounds, namely ectoine and HEG, are applied to the tissue. The degree of keratin dispersion is measured, and improvements to water transport kinetics through the tissue are observed. These effects also lead to better skin hydration in ambient humidities; however, extreme drying conditions can reverse this trend, suggesting that the efficacy of these treatments may be dependent on the environment in which they will be used. Finally, aqueous and organic solvents, as well as the aforementioned keratin dispersing compounds, are applied to the SC in order to change the cohesive properties of the tissue. In this way, interactions of the corneodesmosomes with various treatments can be probed. These experiments reveal the sensitivity of these structures to a variety of treatment types, and highlight the importance of maintaining a proper balance of cohesion in the tissue.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2018; ©2018 |
| Publication date | 2018; 2018 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Bow, Jacob R |
|---|---|
| Degree supervisor | Dauskardt, R. H. (Reinhold H.) |
| Thesis advisor | Dauskardt, R. H. (Reinhold H.) |
| Thesis advisor | Appel, Eric (Eric Andrew) |
| Thesis advisor | Salleo, Alberto |
| Degree committee member | Appel, Eric (Eric Andrew) |
| Degree committee member | Salleo, Alberto |
| Associated with | Stanford University, Department of Materials Science and Engineering. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Jacob R. Bow. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2018. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2018 by Jacob R Bow
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...