Novel reinforcement of corrugated nanofiber tissue-engineered vascular graft to prevent aneurysm formation for arteriovenous shunts in an ovine model

Preclinical in vivo assessment of a cell-free multi-layered scaffold prepared by 3D printing and electrospinning for small-diameter blood vessel tissue engineering in a canine model

“…In situ tissue engineering that is based on direct implantation of a cell-free scaffold into the patient does not need a surgical procedure to harvest cells, which reduces the risk of infection and costs. 17,18 In situ TEVGs can be scaled up and are available offthe-shelf. 18,19 Therefore, the scaffold plays the main role in directing and regulating cell recruitment, cell fate, and tissue development, while the body as a natural bioreactor applies physiological stresses and strains required for tissue regener-ation to the scaffold.…”

“…The scaffold was then longitudinally compressed to 30–45% of its original length for 24 h, followed by elongation to 50–65% of its original length and finally the filament was removed. 17 However, the graft showed a tendency for expansion. To overcome this problem, various methods were employed for reinforcement of the electrospun PCL/PLCL graft.…”

“…Biomaterials Science grafts may face due to bending stresses applied in vivo is lifethreatening stenosis caused by graft kinking. 17,26 The stiffness of the PCL-based vascular graft is a fundamental drawback leading to the lumen collapsing under bending stress. 26 TEVGs with pleated/corrugated walls have been suggested to decrease the risk of graft kinking.…”

History moves in a spiral: Turn to aneurysm prevention of tissue-engineered vascular graft

“…Spiral reinforcement of expanded polytetrafluoroethylene grafts is essential for kinking resistance. Matsushita et al 1 applied such a method for a TEVG to prevent aneurysm formation of arteriovenous (AV) shunts. The requirements for novel AV graft materials include adequate flow rates, easy assessment and cannulation, cost-effectiveness, long-term patency, and minimal complications.…”

“… 5 The latter method implies the use of a biodegradable scaffold that should be kink resistant before surgery and will not lead to aneurysm formation after complete resorption. Matsushita et al 1 solved these preexisting issues by reinforcement of corrugated PCL/PLCL [poly ε-caprolactone/poly (L-lactide-co-ε-caprolactone)] grafts with 2-0 polypropylene suture or a PET/PU (polyethylene terephthalate/polyurethane) outer layer. These grafts were implanted in a U-shape as an AV shunt.…”