In VitroCytotoxicity andIn VivoEffects of a Decellularized Xenogeneic Collagen Scaffold in Nasal Cartilage Repair

Abstract

Tissue engineering is considered a promising future option for nasal cartilage repair. However, until now, an optimal material has not been identified for this specific purpose. Therefore, the aim of this study was to analyze a recently developed decellularized collagen matrix, which has promising material properties for septal cartilage repair. A tetrazolium dye based cytotoxicity assay using rat nasal septum chondrocytes was performed to examine the cytotoxic effects of decellularized cartilage matrices. Unseeded scaffolds as well as scaffolds seeded with chondrocytes were implanted in nasal septum defects in Lewis rats to investigate the cellular and humoral inflammatory responses in the surrounding tissue as well as the effect on the formation of nasal septum perforations. Samples were analyzed histochemically and immunohistochemically after 1, 4, and 12 weeks. Although cells for the cytotoxicity assay were cultured under serum-free conditions for 24 h to increase sensitivity, no cytotoxic effects were detected. Histological and immunohistochemical evidence displayed that the implanted scaffolds induced minor macrophage and lymphocyte infiltration and were well integrated at the contact site to native cartilage and between the mucosal membranes. The biocompatibility index revealed only slightly irritating effects during the study period. Septal perforations were prevented efficiently. In summary, our results provide evidence that decellularized xenogeneic collagen scaffolds are suitable for cartilage tissue engineering. The scaffolds were integrated well into septal cartilage defects without causing a strong inflammatory reaction and prevented the development of nasal septum perforations. Therefore, we envision the possibility to use them in nasal cartilage repair in the future.

Collagenous Extracellular Matrix Biomaterials for Tissue Engineering: Lessons from the Common Sea Urchin Tissue

“…From the practical engineering perspective, currently one of the challenges for the applicability of ECM-DT in tissue engineering is the development of effective decellularization techniques for the removal of cellular components, to minimize immunogenicity upon implantation [35,36,39]. On-going studies to develop effective techniques usually address a combination of physical, chemical and enzymatic methods [174]: physical treatments using cyclical freeze-thawing and ionic solutions can lyse cell membranes, before the enzymatic methods are applied to separate the cellular components from the ECM.…”

“…Since these protein cores of the latter are highly conserved in many species [32,33], their presence in the ECM-DT would help minimize unintended immune response [35]. At the microscopic length scale corresponding to cells, the structural environment is also well-preserved in the ECM-DT; this means that the matrix microenvironment may be effective in directing cellular phenotype via geometric cues [4,36] as well as growth factors for cell attachment, proliferation, migration, and differentiation [3]. Scaffolds made from ECM-DT have been investigated for regeneration in a range of tissues [10,34,37].…”

Naturally derived biomaterials for addressing inflammation in tissue regeneration

“…Scaffolds derived from decellularized matrix (from both allogeneic and xenogeneic sources) have been investigated as materials for regeneration in a range of tissues: heart valve, 24,25,51,52 nasal cartilage, 53 skeletal muscle, 26 gastrointestinal tract, 27,54 ureters, 28 liver, 55 and flexor tendons. 56 Both segmented and whole tissues can be decellularized.…”

“…Removing the cellular component of the transplanted tissue is key to this result as the cellular presence contributes to a predominantly M1 macrophage phenotype. 53,59 …”

“…26,59 Also maintained within the scaffolds are the complex three-dimensional microstructure (important for directing cellular phenotype via geometric cues) 53 and growth factors that have roles in cell attachment, proliferation, migration, and differentiation. 53 Further, the matrix retains its mechanical properties following decellularization allowing for mimicry of the native tissue and long-term function. 25 This property, in particular, negates the need for exogenous chemical cross-linking, presenting a material that is accessible to naturally occurring degradation and remodeling.…”