title: Preparation of a micropatterned rigid-soft composite substrate for probing cellular rigidity sensing.
abstract: Substrate rigidity has been recognized as an important property that affects cellular physiology and functions. While the phenomenon has been well recognized, understanding the underlying mechanism may be greatly facilitated by creating a microenvironment with designed rigidity patterns. This chapter describes in detail an optimized method for preparing substrates with micropatterned rigidity, taking advantage of the ability to dehydrate polyacrylamide gels for micropatterning with photolithography, and subsequently rehydrate the gel to regain the original elastic state. While a wide range of micropatterns may be prepared, typical composite substrates consist of micron-sized islands of rigid photoresist grafted on the surface of polyacrylamide hydrogels of defined rigidity. These islands are displaced by cellular traction forces, for a distance determined by the size of the island, the rigidity of the underlying hydrogel, and the magnitude of traction forces. Domains of rigidity may be created using this composite material to allow systematic investigations of rigidity sensing and durotaxis.
authors.affiliation: Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Wong
authors.affiliation: Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.
authors.forename: Wei-hui
authors.initials: WH
authors.lastname: Guo
authors.affiliation: Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Hoffecker
authors.affiliation: Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.
authors.forename: Yu-li
authors.initials: YL
authors.lastname: Wang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002448:Cell Adhesion / Q000502:physiology*; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D060833:Cellular Microenvironment; D020099:Coated Materials, Biocompatible; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D004129:Dimethylpolysiloxanes; D004852:Epoxy Compounds; D020100:Hydrogels; D011108:Polymers; C520895:SU-8 compound; C016680:polyacrylamide gels; C013830:baysilon
keywords: Cell adhesion; Durotaxis; Mechanosensing; Micropatterning; Photolithography