title: In Vitro Engineering of High Modulus Cartilage-Like Constructs.
abstract: To date, the outcomes of cartilage repair have been inconsistent and have frequently yielded mechanically inferior fibrocartilage, thereby increasing the chances of damage recurrence. Implantation of constructs with biochemical composition and mechanical properties comparable to natural cartilage could be advantageous for long-term repair. This study attempted to create such constructs, in vitro, using tissue engineering principles. Bovine synoviocytes were seeded on nonwoven polyethylene terephthalate fiber scaffolds and cultured in chondrogenic medium for 4 weeks, after which uniaxial compressive loading was applied using an in-house bioreactor for 1 h per day, at a frequency of 1 Hz, for a further 84 days. The initial loading conditions, determined from the mechanical properties of the immature constructs after 4 weeks in chondrogenic culture, were strains ranging between 13% and 23%. After 56 days (sustained at 84 days) of loading, the constructs were stained homogenously with Alcian blue and for type-II collagen. Dynamic compressive moduli were comparable to the high end values for native cartilage and proportional to Alcian blue staining intensity. We suggest that these high moduli values were attributable to the bioreactor setup, which caused the loading regime to change as the constructs developed, that is, the applied stress and strain increased with construct thickness and stiffness, providing continued sufficient cell stimulation as further matrix was deposited. Constructs containing cartilage-like matrix with response to load similar to that of native cartilage could produce long-term effective cartilage repair when implanted.
authors: 1 Division of Oral Biology, School of Dentistry, University of Leeds , Leeds, United Kingdom .
authors: Scott
authors: S
authors: Finlay
authors: 1 Division of Oral Biology, School of Dentistry, University of Leeds , Leeds, United Kingdom .
authors: Bahaa B
authors: BB
authors: Seedhom
authors: 2 School of Computing, University of Leeds , Leeds, United Kingdom .
authors: Duane O
authors: DO
authors: Carey
authors: 2 School of Computing, University of Leeds , Leeds, United Kingdom .
authors: Andy J
authors: AJ
authors: Bulpitt
authors: 3 Department of Pathology, Leeds Institute of Cancer and Pathology, University of Leeds , Leeds, United Kingdom .|4 Leeds Teaching Hospitals NHS Trust , Leeds, United Kingdom .
authors: Darren E
authors: DE
authors: Treanor
authors: 1 Division of Oral Biology, School of Dentistry, University of Leeds , Leeds, United Kingdom .
authors: Jennifer
authors: J
authors: Kirkham
mesh_terms: D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000378:metabolism; D002417:Cattle; D020219:Chondrogenesis; D024043:Collagen Type II / Q000096:biosynthesis; D011093:Polyethylene Terephthalates / Q000737:chemistry*; D013314:Stress, Mechanical; D013583:Synovial Membrane / Q000166:cytology / Q000378:metabolism; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D024043:Collagen Type II; D011093:Polyethylene Terephthalates