Design of chemically activated polymer microwells by one-step UV-lithography for stem cell adhesion.
A novel method to produce sub-microwalled chemically activated polymer microwells by one-step UV-lithography under ambient conditions which are selectively coated with gelatin is introduced. The dimensions as well as the shape of the resulting polystyrene structures are both tunable merely by the irradiation time through one and the same mask. It is shown that the UV-irradiation initiates three effects at those surface areas which are not covered by the mask: (i) oxidation, (ii) cross-linking, and (iii) degradation of polystyrene. The superposition of those effects results in the formation of microscaled, oxidized polymer wells separated by polymer walls, whereas the polymer walls are formed below the mask structures. Topographical changes induced by the UV-irradiation are investigated by atomic force microscopy after different irradiation times. It is shown by X-ray photoelectron spectroscopy and ellipsometric investigations that the chemical composition of the irradiated areas and the degradation of polystyrene reach an equilibrium state after an irradiation time of 10 min. The lateral distribution of the cross-linked and oxidized and of the nonmodified polystyrene after irradiation was determined by fluorescence microscopy and time-of-flight secondary ion mass spectrometry. After the irradiated samples were treated with gelatin solution, it was found that stem cells selectively attach to the irradiated areas. This is due to the selective immobilization of the gelatin on the irradiated polymer areas, which was proved by X-ray photoelectron spectroscopy experiments.
Institute of Functional Interfaces, Forschungszentrum Karlsruhe GmbH, 76021 Karlsruhe, Germany.
Sabrina
S
Montero-Pancera
Vanessa
V
Trouillet
Andre
A
Petershans
Dagmar
D
Fichtner
Andrey
A
Lyapin
Michael
M
Bruns
Thomas
T
Schimmel
Doris
D
Wedlich
Stefan
S
Reichlmaier
Peter G
PG
Weidler
Hartmut
H
Gliemann
D000818:Animals; D002448:Cell Adhesion; D018929:Cell Culture Techniques; D015195:Drug Design; D051379:Mice; D008856:Microscopy, Fluorescence; D056951:Photoelectron Spectroscopy; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology*; D013499:Surface Properties; D014466:Ultraviolet Rays
D011108:Polymers