Reendothelialization of tubular scaffolds by sedimentary and rotative forces: a first step toward tissue-engineered venous graft

PurposeUniform and tubular surface seeding is a prerequisite for tissue-engineered blood vessels to mature properly in a bioreactor. Our objective was to investigate reendothelialization of tubular scaffolds by the synergistic forces of sedimentation and rotation, so as to fabricate tissue-engineered venous grafts in vitro.Materials and methodsCanine bone-marrow-derived endothelial progenitor cells were expanded in vitro. By means of a homemade horizontally rotative device, enzymatically decellularized porcine aortic scaffolds were tubularly seeded with the cells by precoating different matrices, under different rotation speeds, culture durations, and seeding techniques. Incorporation of lipoprotein and antiplatelet aggregation functions of seeded cells were evaluated. The seeding efficacies of various methods were compared by histology and scanning electronic microscopy.ResultsUniform distribution and a larger area of cell coverage were demonstrated by precoating with fibronectin (Fn) and a rotation speed of 2.5 revolutions per hour (rph). The efficacy of rotative seeding was comparable to its static counterpart at 4 h, but decreased at 72 h. The result of single-spin seeding was not different from that of three-spin seeding. The seeded cells showed their natural functions of lipoprotein uptake and antiplatelet aggregative properties. Based on these, we constructed 12 tissue-engineered venous grafts with a cell coverage area of 87.4±6.2%.ConclusionsEfficient and reproducible endothelialization was demonstrated by precoating scaffolds with Fn and by performing single-spin seeding at a speed of 2.5 rph.