title: Raman Spectroscopy Reveals New Insights into the Zonal Organization of Native and Tissue-Engineered Articular Cartilage.
abstract: Tissue architecture is intimately linked with its functions, and loss of tissue organization is often associated with pathologies. The intricate depth-dependent extracellular matrix (ECM) arrangement in articular cartilage is critical to its biomechanical functions. In this study, we developed a Raman spectroscopic imaging approach to gain new insight into the depth-dependent arrangement of native and tissue-engineered articular cartilage using bovine tissues and cells. Our results revealed previously unreported tissue complexity into at least six zones above the tidemark based on a principal component analysis andk-means clustering analysis of the distribution and orientation of the main ECM components. Correlation of nanoindentation and Raman spectroscopic data suggested that the biomechanics across the tissue depth are influenced by ECM microstructure rather than composition. Further, Raman spectroscopy together with multivariate analysis revealed changes in the collagen, glycosaminoglycan, and water distributions in tissue-engineered constructs over time. These changes were assessed using simple metrics that promise to instruct efforts toward the regeneration of a broad range of tissues with native zonal complexity and functional performance.
authors.affiliation: Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom; Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom; Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Mads S
authors.initials: MS
authors.lastname: Bergholt
authors.affiliation: Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom; Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom; Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: St-Pierre
authors.affiliation: Nanoscience Centre, Department of Engineering, University of Cambridge , Cambridge CB3 0FF, United Kingdom.
authors.forename: Giovanni S
authors.initials: GS
authors.lastname: Offeddu
authors.affiliation: Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom; Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom; Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Paresh A
authors.initials: PA
authors.lastname: Parmar
authors.affiliation: Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom; Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom; Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Albro
authors.affiliation: Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom; Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom; Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Puetzer
authors.affiliation: Nanoscience Centre, Department of Engineering, University of Cambridge , Cambridge CB3 0FF, United Kingdom.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Oyen
authors.affiliation: Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom; Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom; Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Molly M
authors.initials: MM
authors.lastname: Stevens