title: Decreased solute adsorption onto cracked surfaces of mechanically injured articular cartilage: towards the design of cartilage-specific functional contrast agents.
abstract: BACKGROUND
  Currently available methods for contrast agent-based magnetic resonance imaging (MRI) and computed tomography (CT) of articular cartilage can only detect cartilage degradation after biochemical changes have occurred within the tissue volume. Differential adsorption of solutes to damaged and intact surfaces of cartilage may be used as a potential mechanism for detection of injuries before biochemical changes in the tissue volume occur.
  
  
  METHODS
  Adsorption of four fluorescent macromolecules to surfaces of injured and sliced cartilage explants was studied. Solutes included native dextran, dextrans modified with aldehyde groups or a chondroitin sulfate (CS)-binding peptide and the peptide alone.
  
  
  RESULTS
  Adsorption of solutes to fissures was significantly less than to intact surfaces of injured and sliced explants. Moreover, solute adsorption at intact surfaces of injured and sliced explants was less reversible than at surfaces of uninjured explants. Modification of dextrans with aldehyde or the peptide enhanced adsorption with the same level of differential adsorption to cracked and intact surfaces. However, aldehyde-dextran exhibited irreversible adsorption. Equilibration of explants in solutes did not decrease the viability of chondrocytes.
  
  
  CONCLUSIONS
  Studied solutes showed promising potential for detection of surface injuries based on differential interactions with cracked and intact surfaces. Additionally, altered adsorption properties at surfaces of damaged cartilage which visually look healthy can be used to detect micro-damage or biochemical changes in these regions. Studied solutes can be used in in vivo fluorescence imaging methods or conjugated with MRI or CT contrast agents to develop functional imaging agents.
authors.affiliation: Department of Chemical Engineering, McGill University, Montreal, QC, Canada.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Moeini
authors.forename: Sarah G A
authors.initials: SG
authors.lastname: Decker
authors.forename: Hooi Chuan
authors.initials: HC
authors.lastname: Chin
authors.forename: Yousef
authors.initials: Y
authors.lastname: Shafieyan
authors.forename: Derek H
authors.initials: DH
authors.lastname: Rosenzweig
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Quinn
mesh_terms: D000327:Adsorption; D000447:Aldehydes / Q000378:metabolism*; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000293:injuries / Q000378:metabolism*; D002809:Chondroitin Sulfates / Q000378:metabolism*; D003287:Contrast Media / Q000378:metabolism*; D003911:Dextrans / Q000378:metabolism*; D004058:Diffusion; D015195:Drug Design; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008855:Microscopy, Electron, Scanning; D013059:Spectrum Analysis, Raman; D014057:Tomography, X-Ray Computed
chemical_list: D000447:Aldehydes; D003287:Contrast Media; D003911:Dextrans; D006025:Glycosaminoglycans; D002809:Chondroitin Sulfates
keywords: Articular cartilage; Contrast agent; Dextrans; FITC; Injury; Solute adsorption