title: Chondrocytes and bone marrow-derived mesenchymal stem cells undergoing chondrogenesis in agarose hydrogels of solid and channelled architectures respond differentially to dynamic culture conditions.
abstract: The objective of this study was to investigate how a combination of different scaffold architectures and rotational culture would influence the functional properties of thick cartilaginous tissues engineered using either chondrocytes or bone marrow-derived mesenchymal stem cells (BM-MSCs). Expanded porcine chondrocytes and BM-MSCs were suspended in 2% agarose and cast in custom-designed moulds to produce either regular solid or channelled construct cylinders. The study consisted of three seperate experimental arms. First, chondrocyte and BM-MSC constructs were cultured in free swelling conditions for 9 weeks. Second, constructs were subjected to rotational culture for a period of 3 weeks. Finally, BM-MSC-seeded constructs were subjected to delayed rotational culture, in which constructs were first cultured for 3 weeks in free swelling conditions, followed by an additional 3 weeks in rotating culture conditions. Constructs were supplemented with TGFβ3 during the first 3 weeks of all experiments. The introduction of channels alone had little effect on the spatial patterns of tissue accumulation in either chondrocyte- or BM-MSC-seeded constructs. The two cell types responded differentially to rotational culture, resulting in the formation of a more homogeneous tissue in chondrocyte-seeded constructs, but significantly inhibiting chondrogenesis of BM-MSCs. This inhibition of chondrogenesis in response to dynamic culture conditions was not observed if BM-MSC-seeded constructs were first maintained in free swelling conditions for 3 weeks prior to rotation. The results of this study demonstrate that bioreactor culture conditions that are beneficial for chondrocyte-based cartilage tissue engineering may be suboptimal for BM-MSCs.
authors.affiliation: Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin, Ireland.
authors.forename: Eamon J
authors.initials: EJ
authors.lastname: Sheehy
authors.forename: Conor T
authors.initials: CT
authors.lastname: Buckley
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kelly
mesh_terms: D000423:Alcian Blue / Q000378:metabolism; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D020219:Chondrogenesis / Q000187:drug effects*; D024043:Collagen Type II / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D020100:Hydrogels / Q000494:pharmacology*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D012399:Rotation; D012685:Sepharose / Q000494:pharmacology*; D013194:Staining and Labeling; D034421:Sus scrofa; D013997:Time Factors; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D024043:Collagen Type II; D006025:Glycosaminoglycans; D020100:Hydrogels; D012685:Sepharose; D000423:Alcian Blue