Cell attachment to PET films coated with a thermo-sensitive block co-polymer with different chemical composition

This objective of this study is to characterize the surface of poly(ethylene terephthalate) (PET) films coated with the thermo-sensitive di-block co-polymers of 2-ethoxyethyl vinyl ether and 2-phenoxyethyl vinyl ether segments (EOVE-b-PhOVE) with a high polydispersity and evaluate the behavior of cell attachment on them at different temperatures. The EOVE segment possessed a low critical solution temperature at 20°C while the hydrophobic PhOVE segment functioned as the site to allow the co-polymer to adsorb onto the PET films. X-ray photoelectron spectroscopy and contact angle measurements revealed that the PET film was coated with the EOVE-b-PhOVE co-polymers. The density of co-polymers coated increased with the concentration of co-polymers used for coating. Irrespective of the co-polymer type, 3T3L1 cells attached on the surface of coated films at 37°C, while the cells showed a spread shape, which is similar to that of cells attached on the original non-coated film. However, when the temperature decreased from 37 to 4°C, the cell shape changed to be round, in contrast to that of the original PET film. The percent increase of round cells depended on the coating density and the polymerization degree of EOVE segment.     

Thermoresponsible Cell Adhesion/Detachment on Transparent Nanocomposite Films Consisting of Poly(2-Methoxyethyl Acrylate) and Clay

Soft, transparent and mechanically tough nanocomposite (M-NC) films composed of poly(2-methoxyethyl acrylate) (PMEA) and inorganic clay (hectorite) were studied as substrates for a living cell harvest system. It was found that five cell types could all be cultivated to confluence on the surface of M-NC n films with clay content (n = 10–23 wt%), although the cells hardly cultivated on the surface of chemically-cross-linked PMEA and linear PMEA films. Further, it was found that the cells cultured on the surfaces of M-NC films can be detached, without any enzymatic digestion, by decreasing the medium temperature and/or simultaneously using gentle pipetting. The detached cell was obtained as a single cell or a contiguous cell sheet, both of which were viable and recultured. From the compositions and surface properties, it was estimated that the cell culture and subsequent cell detachment were attributed to the unique PMEA/clay network. The new soft nanocomposite is potentially a very promising substrate for tissue engineering.     

Examining the Family Context and Relations with Attitudes to School and Scholastic Competence

The importance of family relations in children's adjustment has been established, but questions remain about the contexts that account for these associations. Examining children's reactions to family stress holds promise for advancing our understanding of the relations between attachment and school-related outcomes. The present study examined children's attachment, basal cortisol, and emotional reactions in 235 community families, to understand contributions to children's attitudes to school and scholastic competence. Children's attachment security and normative basal cortisol both contributed to positive school outcomes, while insecurity in the context of low or high cortisol and emotional distress related negatively. Findings highlight the importance of examining stress in family contexts to advance the understanding of children's school functioning, with implications for school mental health interventions.