Reliable decellularization techniques applicable to tendon tissue play a critical role in the field of current tissue engineering. Particularly, an application as three-dimensional culture model for in vitro research and translational approaches to establish graft-based tendon repair as a routine clinical tool represent two main application fields for decellularized tendon scaffolds. Considering methodological issues of tendon decellularization, one of the major challenges lies in the preservation of the tendon-specific extracellular matrix (ECM) architecture to reflect natural tissue characteristic as best as possible. Concurrently, further requirements for high-quality decellularized biological tendon scaffolds include not only the reduction of resident cells, but also an ensured cytocompatibility.
To date, a large number and a wide variety of decellularization protocols for natural tendon tissue have already been investigated and usually, physical as well as chemical and/or enzyme-based treatments are used for the purpose of decellularization. However, to the best of our knowledge, there is a lack of evidence-based protocols for the processing of full-thickness large tendon samples, such as the equine flexor tendons.
Therefore, the here presented protocol describes a reliable procedure to decellularize equine superficial digital flexor tendons by using a combined treatment of physical decellularization in the form of repetitive freeze-thaw cycles, and of chemical decellularization with the non-ionic detergent Triton X-100. The decellularization effectiveness evaluated by reduction of cell and DNA content, the influence of decellularization on the morphology of the tendon extracellular matrix (ECM) as well as the cytocompatibility of the decellularized tendon scaffolds obtained have been investigated previously. Based on this previous study, the here present protocol is an effective procedure, particularly applicable for large tendon specimens.
Schulze-Tanzil G, Al-Sadi O, Ertel W, Lohan A (2012) Decellularized tendon extracellular matrix—a valuable approach for tendon reconstruction? Cell 1(4):1010–1028CrossRefGoogle Scholar
Burk J, Erbe I, Berner D, Kacza J, Kasper C, Pfeiffer B et al (2014) Freeze-thaw cycles enhance decellularization of large tendons. Tissue Eng Part C Methods 20(4):276–284CrossRefPubMedGoogle Scholar
Youngstrom DW, Barrett JG, Jose RR, Kaplan DL (2013) Functional characterization of detergent-decellularized equine tendon extracellular matrix for tissue engineering applications. PLoS One 8(5):e64151ADSCrossRefPubMedPubMedCentralGoogle Scholar
Bottagisio M, Pellegata AF, Boschetti F, Ferroni M, Moretti M, Lovati AB (2016) A new strategy for the decellularisation of large equine tendons as biocompatible tendon substitutes. Eur Cell Mater 32:58–73CrossRefPubMedGoogle Scholar
Dowling BA, Dart AJ (2005) Mechanical and functional properties of the equine superficial digital flexor tendon. Vet J 170(2):184–192CrossRefPubMedGoogle Scholar
Thorpe CT, Clegg PD, Birch HL (2010) A review of tendon injury: why is the equine superficial digital flexor tendon most at risk? Equine Vet J 42(2):174–180CrossRefPubMedGoogle Scholar
Patterson-Kane JC, Rich T (2014) Achilles tendon injuries in elite athletes: lessons in pathophysiology from their equine counterparts. ILAR J 55(1):86–99CrossRefPubMedGoogle Scholar
Roth SP, Glauche SM, Plenge A, Erbe I, Heller S, Burk J (2017) Automated freeze-thaw cycles for decellularization of tendon tissue—a pilot study. BMC Biotechnol 17(1):13CrossRefPubMedPubMedCentralGoogle Scholar
Gilbert TW, Sellaro TL, Badylak SF (2006) Decellularization of tissues and organs. Biomaterials 27(19):3675–3683PubMedGoogle Scholar
Azuma C, Tohyama H, Nakamura H, Kanaya F, Yasuda K (2007) Antibody neutralization of TGF-β enhances the deterioration of collagen fascicles in a tissue-cultured tendon matrix with ex vivo fibroblast infiltration. J Biomech 40(10):2184–2190CrossRefPubMedGoogle Scholar
Omae H, Zhao C, Sun YL, An K-N, Amadio PC (2009) Multilayer tendon slices seeded with bone marrow stromal cells: a novel composite for tendon engineering. J Orthop Res 27(7):937–942CrossRefPubMedPubMedCentralGoogle Scholar
Stewart AA, Barrett JG, Byron CR, Yates AC, Durgam SS, Evans RB et al (2009) Comparison of equine tendon-, muscle-, and bone marrow-derived cells cultured on tendon matrix. Am J Vet Res 70(6):750–757CrossRefPubMedGoogle Scholar
Smeak DD, Olmstead ML (1984) Infections in clean wounds: the roles of the surgeon, environment, and host. The compendium on continuing education for the practicing veterinarian. Comp Cont Educ 6:626Google Scholar