Investigation of a small-diameter decellularised artery as a potential scaffold for vascular tissue engineering; biomechanical evaluation and preliminary cell seeding.

The development of a small-diameter tissue engineered blood vessel (TEBV), with equivalent mechanical properties to the vessel being replaced, may provide a potential solution to the limitations associated with natural and synthetic bypass grafts of small-diameter vessels. This study presents the biomechanical properties of small-diameter (<4mm) porcine coronary arteries (PCA) and the corresponding natural matrix scaffold of the artery achieved through short-term decellularisation. Tubular segments, up to 50mm in length, of PCA were perfused with 0.1М sodium hydroxide (NaOH) for 3 to 12h to achieve the natural matrix scaffold. Uniaxial tensile, inflation and permeability tests were performed on non-decellularised and decellularised sections within 24h of slaughter to determine the alteration in mechanical properties as a result of decellularisation. A treatment time of 9h achieved decellularisation as all cell nuclei were appropriately disrupted and there was an absence of smooth muscle in the vascular wall. Uniaxial tensile and inflation tests confirmed the scaffold maintains its non-linear response, however a less stiff, more distensible low-load response and stiffer high-load response was found compared to non-decellularised sections. Vascular smooth muscle cells were successfully seeded to the lumen, abluminal side and lateral edges of decellularised sections and attachment and infiltration of the xenogeneic cells after 15 days confirmed the viability of the PCA scaffold as a suitable environment for cell growth and infiltration. An extended decellularisation treatment time increased the porosity whilst maintaining the mechanical integrity of the scaffold and this may optimise the repopulation of the scaffold. This study provides valuable information for the development of an optimum TEBV, while also establishing the potential of this natural matrix scaffold to be used as a graft or vascular tissue engineering scaffold.