Interfacial and Cohesive Properties of Corneal Epithelium
CELL PRESS. 2021: 169A
View details for Web of Science ID 000629601401071
Tuning corneal epithelial cell adhesive strength with varying crosslinker content in silicone hydrogel materials.
Translational vision science & technology
2020; 9 (6): 3
Purpose: To quantify the effect of silicone hydrogel crosslink density on the adhesion at corneal epithelial cells/silicone hydrogel contact lens interface.Methods: A custom-built rheometer, referred to as the live cell monolayer rheometer, was used to measure the adhesive strengths between corneal epithelial cell monolayers and silicone hydrogel lens surfaces. The resulting stress relaxations of senofilcon A-derived silicone hydrogel materials with varying crosslinking densities and delefilcon A were tested. Senofilcon A-like materials labeled L1, L2, L3, L4, and L5 contained crosslinker concentrations of 1.2, 1.35, 1.5, 1.65, and 1.8 wt%, respectively. The residual modulus measured from the live cell monolayer rheometer provided a direct indication of adhesive attachment.Results: Within the senofilcon-derived series, the adhesive strength shows a surprising minimum with respect to crosslink density. Specifically, L1 (1.20%) has the highest adhesive strength of 39.5 ± 11.2 Pa. The adhesive strength diminishes to a minimum of 11.2 ± 2.1 Pa for L3, whereafter it increases to 14.5 ± 2.5 Pa and 18.1 ± 5.1 Pa for L4 and L5, respectively. The delefilcon A lens exhibits a comparable adhesive strength of 27.8 ± 6.3 Pa to L1.Conclusions: These results demonstrated that increasing the crosslink density has a nonmonotonic influence on the adherence of lenses to mucin-expressing corneal epithelial cells, which suggests a competition mechanism at the cell/lens interface.Translational Relevance: Because the adhesiveness of contact lenses to ocular tissues may impact the comfort level for lens wearers and affect ease of removal, this study suggests that lens adhesion can be optimized through the control of crosslink density.
View details for DOI 10.1167/tvst.9.6.3
View details for PubMedID 32821500
- Thermodynamic Model of Solvent Effects in Semiflexible Diblock and Random Copolymer Assembly MACROMOLECULES 2018; 51 (11): 4167–77
Coloration mechanisms and phylogeny of Morpho butterflies
JOURNAL OF EXPERIMENTAL BIOLOGY
2016; 219 (24): 3936–44
Morpho butterflies are universally admired for their iridescent blue coloration, which is due to nanostructured wing scales. We performed a comparative study on the coloration of 16 Morpho species, investigating the morphological, spectral and spatial scattering properties of the differently organized wing scales. In numerous previous studies, the bright blue Morpho coloration has been fully attributed to the multi-layered ridges of the cover scales' upper laminae, but we found that the lower laminae of the cover and ground scales play an important additional role, by acting as optical thin film reflectors. We conclude that Morpho coloration is a subtle combination of overlapping pigmented and/or unpigmented scales, multilayer systems, optical thin films and sometimes undulated scale surfaces. Based on the scales' architecture and their organization, five main groups can be distinguished within the genus Morpho, largely agreeing with the accepted phylogeny.
View details for DOI 10.1242/jeb.148726
View details for Web of Science ID 000391279300017
View details for PubMedID 27974535