Optimizing nutrient channel spacing and revisiting TGF-beta in large engineered cartilage constructs

JOURNAL OF BIOMECHANICS

卷:49

Article

Cigan, Alexander D. ; Nims, Robert J. ; Vunjak-Novakovic, Gordana ; Hung, Clark T. ; Ateshian, Gerard A.

关键词: Tissue engineering;    Cartilage;    Agarose;    Chondrocytes;    Nutrient transport;    Growth factors;   

DOI  :  10.1016/j.jbiomech.2016.05.020

来源: Elsevier

【 摘 要 】

Cartilage tissue engineering is a promising approach to treat osteoarthritis. However, current techniques produce tissues too small for clinical relevance. Increasingly close-packed channels have helped overcome nutrient transport limitations in centimeter-sized chondrocyte-agarose constructs, yet optimal channel spacings to recapitulate native cartilage compositional and mechanical properties in constructs this large have not been identified. Transient active TGF-beta treatment consistently reproduces native compressive Young's modulus (E-Y) and glycosaminoglycan (GAG) content in constructs, but standard dosages of 10 ng/mL exacerbate matrix heterogeneity. To ultimately produce articular layer-sized constructs, we must first optimize channel spacing and investigate the role of TGF-beta in the utility of channels. We cultured circle divide 10 mm constructs with 0, 12, 19, or 27 nutrient channels (circle divide 1 mm) for 6-8 weeks with 0, 1, or 10 ng/mL TGF-beta; subsequently we analyzed them mechanically, biochemically, and histologically. Constructs with 12 or 19 channels grew the most favorably, reaching E-Y = 344 +/- 113 kPa and GAG and collagen contents of 10.8 +/- 1.2% and 2.2 +/- 0.2% of construct wet weight, respectively. Constructs with 27 channels had significantly less deposited GAG than other groups. Channeled constructs given 1 or 10 ng/mL TGF-beta developed similar properties. Without TGF-beta, constructs with 0 or 12 channels exhibited properties that were indistinguishable, and lower than TGF-beta-supplemented constructs. Taken together, these results emphasize that nutrient channels are effective only in the presence of TGF-beta, and indicate that spacings equivalent to 12 channels in 010 mm constructs can be employed in articular-layer-sized constructs with reduced dosages of TGF-beta. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

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