Effect of Intensified Decellularization of Equine Carotid Arteries on Scaffold Biomechanics and Cytotoxicity

Abstract

Decellularized equine carotid arteries (dEAC) are suggested to represent an alternative for alloplastic vascular grafts in haemodialysis patients to achieve vascular access. Recently it was shown that intensified detergent treatment completely removed cellular components from dEAC and thereby significantly reduced matrix immunogenicity. However, detergents may also affect matrix composition and stability and render scaffolds cytotoxic. Therefore, intensively decellularized carotids (int-dEAC) were now evaluated for their biomechanical characteristics (suture retention strength, burst pressure and circumferential compliance at arterial and venous systolic and diastolic pressure), matrix components (collagen and glycosaminoglycan content) and indirect and direct cytotoxicity (WST-8 assay and endothelial cell seeding) and compared with native (n-EAC) and conventionally decellularized carotids (con-dEAC). Both decellularization protocols comparably reduced matrix compliance (venous pressure compliance: 32.2 and 27.4% of n-EAC; p < 0.01 and arterial pressure compliance: 26.8 and 23.7% of n-EAC, p < 0.01) but had no effect on suture retention strength and burst pressure. Matrix characterization revealed unchanged collagen contents but a 39.0% (con-dEAC) and 26.4% (int-dEAC, p < 0.01) reduction of glycosaminoglycans, respectively. Cytotoxicity was not observed in either dEAC matrix which was also displayed by an intact endothelial lining after seeding. Thus, even intensified decellularization generates matrix scaffolds highly suitable for vascular tissue engineering purposes, e.g., the generation of haemodialysis shunts.

Decellularized equine carotid artery layers as matrix for regenerated neurites of spiral ganglion neurons

“…A detailed protocol and characterization of the here-tested dEAC has been described previously by Böer et al The scaffolds were decellularized by a detergent-based approach and thoroughly characterized with respect to their residual proteins, 12,13 their biocompatibility in vitro 14,15 and in vivo 16 and their biomechanical properties. 14 It was shown that for complete removal of cellular components and a maximized biocompatibility in vitro and in vivo an intensified decellularization process was necessary. 13,14,16 Yet, biomechanical properties were maintained and the scaffold structure was preserved.…”

“…14 It was shown that for complete removal of cellular components and a maximized biocompatibility in vitro and in vivo an intensified decellularization process was necessary. 13,14,16 Yet, biomechanical properties were maintained and the scaffold structure was preserved. 13,14 This structure comprises three distinct layers of equine carotid arteries (EAC): the outer tunica adventitia is known to display a randomized pattern, while the tunica media displays a structure based on parallel elastin fibers and the tunica intima has almost no pattern.…”

“…13,14,16 Yet, biomechanical properties were maintained and the scaffold structure was preserved. 13,14 This structure comprises three distinct layers of equine carotid arteries (EAC): the outer tunica adventitia is known to display a randomized pattern, while the tunica media displays a structure based on parallel elastin fibers and the tunica intima has almost no pattern. 17,18 Moreover, intensively (d)EAC have been shown to be recellularized, with human cells, 14 and remodeled in vivo to an extremely high extent.…”

“…13,14 This structure comprises three distinct layers of equine carotid arteries (EAC): the outer tunica adventitia is known to display a randomized pattern, while the tunica media displays a structure based on parallel elastin fibers and the tunica intima has almost no pattern. 17,18 Moreover, intensively (d)EAC have been shown to be recellularized, with human cells, 14 and remodeled in vivo to an extremely high extent. 16 By these investigations and since the structure of theses layers differ considerably, dEAC most likely are highly promising for cell adhesion and support of neurite growth.…”

Small Diameter Xenogeneic Extracellular Matrix Scaffolds for Vascular Applications

“…Unfortunately, further testing on rod-decellularized ECM scaffolds demonstrated that harsher decellularization methods had negative effects on the ECM structure and function. 193 Rod decellularization resulted in ECM scaffold distention, disruption of structural protein macromolecular structure and significantly reduced compliance. Consequently, despite the relatively encouraging effect of rod decellularization on resultant scaffold antigen content, disruption of the remaining ECM components induced by this approach has high risk of inducing innate immune and/or nonimmunogenic failure mechanisms (e.g., aneurysmal dilation).…”