A Novel Seamless Elastic Scaffold for Vascular Tissue Engineering

Abstract

Tissue-engineered vascular grafts have been investigated as a substitute for prosthetic vascular grafts. The current scaffolds have several limitations due to weak mechanical properties in withstanding the pressure of blood vessel. A gel-spinning molding device including three-separate drivers that make a cylindrical shaft turn on its axis, orbit, and concurrently move up and down was developed for preparing seamless fibrous tubular scaffolds for vascular grafts. A seamless double-layered tubular scaffold, which was composed of an outer fibrous network and inner porous layer, was fabricated by using the device for the spinning of poly(L-lactide-co-caprolactone) (PLCL, 50:50) solution as a gel state on a rotating cylindrical shaft that had been dip-coated with the mixture of PLCL solution and NaCl particles. A scaffold that had an inner layer fabricated with 30% salts, below 20 mum in salt size, and more than 100 microm in thickness, was found to be optimal from a blood leakage test. The burst pressures of the scaffolds were more than 900 mmHg. The scaffolds exhibited 550-670% elongation-at-break. The measured circumferential and longitudinal tensile strengths of the scaffolds were 3.62 +/- 0.68 and 2.64 +/- 0.41 MPa, respectively. The suture retention strength of the scaffold was measured to be 7.68 +/- 0.75 N. These mechanically strong and elastic properties of the newly developed scaffolds provide an important basis for blood vessel tissue engineering.

Elastic, double-layered poly (l-lactide-co-ϵ-caprolactone) scaffold for long-term vascular reconstruction

“…Various strategies have been used to inhibit these processes and prolong the graft patency, including coating the grafts with various anticoagulants, antiplatelet factors, and antiproliferation agents. [20][21][22][23][24][25] An in situ tissue engineering approach is clinically more attractive, which involves the implantation of a cell-free scaffold. 7,17 Compliance mismatch between a native artery and an artificial graft is known to cause a graft failure during a prolonged implantation of an artificial graft.…”

“…19 PLCL copolymers have been applied as a biomaterial for vascular graft applications due to their high elasticity. 20 –25…”

Emerging Techniques in Stratified Designs and Continuous Gradients for Tissue Engineering of Interfaces

“…There also exist stratifications of cell types 2,14,33 or other features 7,20,24,27,63,71 for vasculature network interface formation. Although it could be argued that a stratified approach does not yield a “true” continuous gradient, it can have many discrete advantages over continuous gradients.…”

“…Kim et al 27 utilized a poly(L-lactide-co- ε -caprolactone) (PLCL) solution spun onto a tubular shaft in a non-solvent to create a bi-layered pore stratification (Table 2). The shaft was pre-treated with sodium chloride (NaCl), which became incorporated with the inner layer of the PLCL fibers during deposition.…”

Embryonic Stem Cells for Tissue Biocompatibility, Angiogenesis, and Inflammation Testing

“…Copolymerization of L-lactide with ε-caprolactone allows specific adjustment of properties of the polymer with regard to firmness, melting point, and biodegradation. Such materials are currently used in the production of blood vessel grafts [Centola et al, 2010;Kim et al, 2010] and in cartilage and bone regeneration [Idris et al, 2010;Li et al, 2013], as well as for closure of gastric perforations in laparoscopic surgery [Bertleff et al, 2009].…”