Development of the wing-attached rod for acceleration of "Biotube" vascular grafts fabrication in vivo.

To accelerate the fabrication of in vivo tissue-engineered autologous vascular prosthetic tissues, the "Biotube," a novel wing-attached rod mold was designed for a tissue rolling technique based on a two-step in body tissue incubation (IBTI) process. The new mold consisted of a silicone rod (3-mm diameter, 23-mm length) partly connected to a poly(ethylene terephthalate) film (a wing, 23 x 19 x 0.1 mm). While the molds were embedded into the dorsal subcutaneous pouches of rabbits for 2 weeks (primary IBTI), they were encapsulated fully with thin connective tissues. After removal of the wing materials, the remaining saccular membranous tissues were rolled up on the core tubular tissues that had formed around the silicone rods. Following another 2-week embedding of the assembled tissues (secondary IBTI), the layered tissues fused to each other to form compliant and stiff tubular tissues, "Rolled Biotubes." The wall thickness of the Rolled Biotubes was about 800 microm and the burst strength was about 4000 mmHg, both of which were significantly higher than those of Biotubes prepared by one-step, 4-week IBTI or two-step, 2-week IBTI (p < 0.05). A Rolled Biotube could be applied as middle or large caliber arterial prostheses.