title: 3,4-Dihydroxy-L-Phenylalanine as a Novel Covalent Linker of Extracellular Matrix Proteins to Polyacrylamide Hydrogels with a Tunable Stiffness.
abstract: Cells acquire mechanical information from their surrounding and convert this into biochemical activity. The concept and mechanism behind this cellular mechanosensing and mechanotransduction are often studied by means of two-dimensional hydrogels. Polyacrylamide hydrogels (PAAMs) offer chemical, mechanical, and optical advantages but due to their inert surface do not allow protein and cell adherence. Several cross-linkers have been used to functionalize the surface of PAAMs with extracellular matrix (ECM) proteins to enable cell culture. However, the most commonly used cross-linkers are either unstable, expensive, or laborious and often show heterogeneous coating or require PAAM modification. Here, we introduce 3,4-dihydroxy-l-phenylalanine (L-DOPA) as a novel cross-linker that can functionalize PAAMs with ECM without the above-mentioned disadvantages. A homogenous collagen type I and fibronectin coating was observed after L-DOPA functionalization. Fibroblasts responded to differences in PAAMs' stiffness; morphology, cell area, and protein localization were all affected as expected, in accordance with literature where other cross-linkers were used. In conclusion, L-DOPA can be used as a cross-linker between PAAMs and ECM and represents a novel, straightforward, nonlaborious, and robust method to functionalize PAAMs for cell culture to study cell mechanosensing.
authors.affiliation: 1 Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands .
authors.forename: Olaf Y
authors.initials: OY
authors.lastname: Wouters
authors.affiliation: 1 Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands .
authors.forename: Diana T A
authors.initials: DT
authors.lastname: Ploeger
authors.affiliation: 1 Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands .|2 Synvolux Therapeutics , Groningen, The Netherlands .
authors.forename: Sander M
authors.initials: SM
authors.lastname: van Putten
authors.affiliation: 1 Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands .
authors.forename: Ruud A
authors.initials: RA
authors.lastname: Bank