A Versatile Gradient of Biomolecules for Regulating Cell Behaviour

Surface Chemoselective Phototransformation of C–H Bonds on Organic Polymeric Materials and Related High-Tech Applications

“…In addition to homogeneous photooxidation, gradient photooxidation controlled by adjusting the irradiation time has been utilized to create gradient functional PSt and poly(ethylene terephthalate) (PET) surfaces for use in bioimmobilization. 109 The key to this method is having a UV activation process that generates a gradient in reactive initiation sites on the surface. To achieve this aim, the exposed area of the polymer film surface is controlled by a narrow slit, and as the slit is translated above the sample, different areas are subjected to ozone-generating UV for different irradiation times.…”

“…In addition to homogeneous photooxidation, gradient photooxidation controlled by adjusting the irradiation time has been utilized to create gradient functional PSt and poly(ethylene terephthalate) (PET) surfaces for use in bioimmobilization . The key to this method is having a UV activation process that generates a gradient in reactive initiation sites on the surface.…”

Impact of vitronectin concentration and surface properties on the stable propagation of human embryonic stem cells

“…An in situ polymerized, grafted poly͑acrylic acid͒ ͑PAA͒ brush was developed on PET using the method described by Racine et al, 21 with a UV activation time of 15 min and a UV polymerization time of 5 min. The surface density of the carboxylic acid groups on PET-PAA was quantified by Toluidine Blue O ͑Sigma-Aldrich T3260͒ staining and titration, as described by Racine et al 21 Bare PET films and PET-PAA films were briefly rinsed with water and dried under nitrogen airflow before sterilizing them for 15 min within 70% ethanol, followed by twice rinsing in sterile PBS, in the sterile environment of a biological safety cabinet ͑NuAire Nu-425-400E͒. The PET-PAA surfaces were activated by a 15 min exposure to a pH 10 buffer solution, consisting of 0.0214M NaOH ͑Goodrich Chemical Enterprise, Singapore͒ and 0.05M sodium hydrogen carbonate ͑Merck͒, which ensured charging of the PAA brush.…”