title: Transient supplementation of anabolic growth factors rapidly stimulates matrix synthesis in engineered cartilage.
abstract: The purpose of the presented work is to examine the response of engineered cartilage to a transient, 2-week application of anabolic growth factors compared to continuous exposure in in vitro culture. Immature bovine chondrocytes were suspended in agarose hydrogel and cultured for 28 days (Study 1) or 42 days (Study 2) in chondrogenic media with TGF-β1, TGF-β3, or IGF-I either added for only the first 14 days in culture or added to the media for the entire study period. In both studies, there were no statistical differences in tissue mechanical or biochemical properties between the growth factors on day 14. In Study 1, growth factor removal led to a significant and drastic increase in Young's modulus and glycosaminoglycans content compared to continuously exposed controls on day 28. In Study 2, both TGF-β1 and β3 led to significantly higher mechanical properties and collagen content vs. IGF-I on day 42. These results indicate that the rapid rise in tissue properties (previously observed with TGF-β3 only) is not dependent on the type but rather the temporal application of the anabolic growth factor. These findings shed light on possible techniques to rapidly develop engineered cartilage tissue for the future treatment of osteoarthritis.
authors.affiliation: Research Division, Hospital for Special Surgery, New York, NY 10021, USA.
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Ng
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: O'Conor
authors.forename: Lindsay E
authors.initials: LE
authors.lastname: Kugler
authors.forename: James L
authors.initials: JL
authors.lastname: Cook
authors.forename: Gerard A
authors.initials: GA
authors.lastname: Ateshian
authors.forename: Clark T
authors.initials: CT
authors.lastname: Hung
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism; D020219:Chondrogenesis / Q000502:physiology; D003094:Collagen / Q000032:analysis / Q000378:metabolism; D019245:Compressive Strength; D055119:Elastic Modulus; D006025:Glycosaminoglycans / Q000032:analysis / Q000378:metabolism; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D012685:Sepharose; D023822:Tissue Engineering / Q000379:methods*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D053782:Transforming Growth Factor beta3 / Q000378:metabolism
chemical_list: D006025:Glycosaminoglycans; D036341:Intercellular Signaling Peptides and Proteins; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007334:Insulin-Like Growth Factor I; D003094:Collagen; D012685:Sepharose