Article: Puetzer, JL; Koo, E; Bonassar, LJ; (2015) “Induction of Fiber Alignment and Mechanical Anisotropy in Tissue Engineered Menisci with Mechanical Anchoring”, Journal of Biomechanics, 48 (8):1436-1443
Abstract: This study investigated the effect of mechanical anchoring on the development of fiber organization and anisotropy in anatomically shaped tissue engineered menisci. Bovine meniscal fibrochondrocytes were mixed with collagen and injected into molds designed to produce meniscus implants with 12 mm extensions at each horn. After a day of static culture, 10 and 20 mg/ml collagen menisci were either clamped or unclamped and cultured for up to 8 weeks. Clamped menisci were anchored in culture trays throughout culture to mimic the native meniscus horn attachment sites, restrict contraction circumferentially, and encourage circumferential alignment. Clamped menisci retained their size and shape, and by 8 weeks developed circumferential and radial fiber organization that resembled native meniscus. Clamping also increased collagen accumulation and improved mechanical properties compared to unclamped menisci. Enhanced organization in clamped menisci was further reflected in the development of anisotropic tensile properties, with 2-3 fold higher circumferential moduli compared to radial moduli, a similar ratio to native meniscus. Ten and 20 mg/ml clamped menisci had similar levels of organization, with 20 mg/ml menisci producing larger diameter fibers and significantly better mechanical properties. Collectively, these data demonstrate the benefit of using bio-inspired mechanical boundary conditions to drive the formation of a highly organized collagen fiber network. (C) 2015 Elsevier Ltd. All rights reserved.
Funding Acknowledgement: National Science Foundation’s Graduate Research Fellowship Program; Cornell BME NSF GK-12 program [DGE 0841291]; Microscopy and Imaging Facility, Life Sciences Core Laboratories Center at Cornell University
Funding Text: The authors would like to thank the National Science Foundation’s Graduate Research Fellowship Program, the Cornell BME NSF GK-12 program: DGE 0841291, the Microscopy and Imaging Facility, Life Sciences Core Laboratories Center at Cornell University, Dr. Hod Lipson, John Cheeseborough, Dr. Cynthia Reinhart-King, Mary Clare McCorry, Shawn Carey and the members of the Bonassar Lab for their support in this research.