Effect of substrate mechanics on chondrocyte adhesion to modified alginate surfaces.
This study characterized the attachment of chondrocytes to RGD-functionalized alginate by examining the effect of substrate stiffness on cell attachment and morphology. Bovine chondrocytes were added to wells coated with 2% alginate or RGD-alginate. The alginate was crosslinked with divalent cations ranging from 1.25 to 62.5 mmol/g alginate. Attachment to RGD-alginate was 10-20 times higher than attachment to unmodified alginate and was significantly inhibited by antibodies to integrin subunits alpha3l and beta1, cytochalasin-D, and soluble RGD peptide. The equilibrium level and rate of attachment increased with crosslink density and substrate stiffness. Substrate stiffness also regulated chondrocyte morphology, which changed from a rounded shape with nebulous actin on weaker substrates to a predominantly flat morphology with actin stress fibers on stiffer substrates. The dependence of attachment on integrins and substrate stiffness suggests that chondrocyte integrins may play a role in sensing the mechanical properties of the matrices to which they are attached.
Genes
Nicholas G
NG
Center for Tissue Engineering, University of Massachusetts Medical School, Worcester, MA, USA.
Rowley
Jonathan A
JA
Mooney
David J
DJ
Bonassar
Lawrence J
LJ
D000464:Alginates / Q000737:chemistry* / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001464:Barium / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D002118:Calcium / Q000737:chemistry; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D019902:Chondrocytes / Q000166:cytology* / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000494:pharmacology; D015638:Cytochalasin D / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D009842:Oligopeptides / Q000737:chemistry* / Q000494:pharmacology; D013499:Surface Properties
D000464:Alginates; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D009842:Oligopeptides; D015638:Cytochalasin D; D001464:Barium; C047981:arginyl-glycyl-aspartic acid; D002118:Calcium