Micropatterning of hydrogels by soft embossing.
Conventional in situ hydrogel micropatterning techniques work successfully for relatively stiff hydrogels, but they often result in locally damaged surfaces upon demolding in the case of soft and fragile polymer networks formed at low precursor concentration. To overcome this limitation, we have developed a versatile method, termed soft embossing, for the topographical micropatterning of fragile chemically cross-linked polymer hydrogels. Soft embossing is based on the imprinting of a microstructured template into a gel surface that is only partially cross-linked. Free functional groups continue to be consumed and upon complete cross-linking irreversibly confine the microstructure on the gel surface. Here we identify and optimize the parameters that control the soft embossing process and show that this method allows the fabrication of desired topographies with good fidelity. Finally, one of the produced gel micropatterns, an array of microwells, was successfully utilized forculturing and analyzing live single hematopoietic stem cells. Confining the stem cells to their microwells allowed for efficient quantification of their growth potential during in vitro culturing.
Laboratory of Stem Cell Bioengineering and Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Stefan
S
Kobel
Monika
M
Limacher
Samy
S
Gobaa
Thierry
T
Laroche
Matthias P
MP
Lutolf
D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D003432:Cross-Linking Reagents / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D005139:Eyeglasses; D006412:Hematopoietic Stem Cells / Q000166:cytology; D020100:Hydrogels / Q000737:chemistry*; D007700:Kinetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal / Q000379:methods; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D012212:Rheology / Q000379:methods; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors
D003432:Cross-Linking Reagents; D004129:Dimethylpolysiloxanes; D020100:Hydrogels; D011108:Polymers; D013438:Sulfhydryl Compounds; D011092:Polyethylene Glycols; C013830:baysilon