A thermoresponsive substrate based on a triblock copolymer, poly(N‐isopropylacrylamide)‐block‐poly[(R)‐3‐hydroxybutyrate]‐block‐poly(N‐isopropylacrylamide) (PNIPAAm‐PHB‐PNIPAAm), co‐coated with gelatin, was developed for the culture and non‐enzymatic recovery of mouse embryonic stem cells. After culture, the cells could be detached by cooling at 4 °C for 20 min without trypsin digestion. The embryonic stem cells remained undifferentiated after culture on the gelatin/copolymer‐coated surfaces, similar to standard culture techniques. Overall, the triblock copolymer coating was superior to the PNIPAAm homopolymer coating in terms of supporting better cell growth, being more stable, presenting a more homogeneous surface coating, and maintaining pluripotency of the embryonic stem cells.
The range of application of polyurethanes has been limited by their poor hemocompatibility and inability to resist non‐specific binding of biomolecules and cells. In this work, a non‐adhesive PU‐based material was synthesized via the copolymerization of PU with dermatan sulfate. Incorporation of DS into the PU backbone dramatically increased material hydrophilicity and decreased protein adsorption. The in vitro adhesion of several cell types, including platelets, also significantly decreased with increasing DS content. Both the physical and biological properties of the DS contributed to the anti‐adhesive properties of the PU/DS copolymer, and this anti‐adhesive nature of PU/DS renders this new biomaterial attractive for blood‐contacting or non‐fouling applications.
Poly(dimethylsiloxane)‐block‐poly(methyl methacrylate)‐block‐poly(2,2,3,3,4,4,4‐heptafluorobutyl methacrylate) was successfully synthesized via ATRP. The chemical composition and structure of the copolymer was characterized by NMR and FT‐IR spectroscopy and molecular weight measurement. Gel permeation chromatography was used to study the molecular weight distribution of the triblock copolymer. The surface properties of the resulting copolymer were investigated. The effects of fluorine content and bulk structure on surface energy were investigated by static water contact angle measurements. Surface composition was studied by XPS.
We present a two‐fold study designed to elucidate the adhesion mechanism of human U937 monocytes on novel N‐rich thin films deposited by plasma‐ and VUV photo‐polymerisation, so‐called “PVP:N” materials. It is shown that there exist sharply‐defined (“critical”) surface‐chemical conditions that are necessary to induce cell adhesion. By comparing the film chemistries at the “critical” conditions, we demonstrate the dominant role of primary amines in the cell adhesion mechanism. Quantitative real‐time RT‐PCR experiments using U937 cells that had adhered to PVP:N materials for up to 24 h are presented. The adhesion induces a transient expression of cytokines, markers of macrophage activation, as well as a more sustained expression of PPARγ and ICAM‐I.
