title: Bioresorbable elastomeric vascular tissue engineering scaffolds via melt spinning and electrospinning.
abstract: Current surgical therapy for diseased vessels less than 6mm in diameter involves bypass grafting with autologous arteries or veins. Although this surgical practice is common, it has significant limitations and complications, such as occlusion, intimal hyperplasia and compliance mismatch. As a result, cardiovascular biomaterials research has been motivated to develop tissue-engineered blood vessel substitutes. In this study, vascular tissue engineering scaffolds were fabricated using two different approaches, namely melt spinning and electrospinning. Small diameter tubes were fabricated from an elastomeric bioresorbable 50:50 poly(l-lactide-co-epsilon-caprolactone) copolymer having dimensions of 5mm in diameter and porosity of over 75%. Scaffolds electrospun from two different solvents, acetone and 1,1,1,3,3,3-hexafluoro-2-propanol were compared in terms of their morphology, mechanical properties and cell viability. Overall, the mechanical properties of the prototype tubes exceeded the transverse tensile values of natural arteries of similar caliber. In addition to spinning the polymer separately into melt-spun and electrospun constructs, the approach in this study has successfully demonstrated that these two techniques can be combined to produce double-layered tubular scaffolds containing both melt-spun macrofibers (<200microm in diameter) and electrospun submicron fibers (>400nm in diameter). Since the vascular wall has a complex multilayered architecture and unique mechanical properties, there remain several significant challenges before a successful tissue-engineered artery is achieved.
authors.affiliation: Fiber and Polymer Science, North Carolina State University, Raleigh, NC 27695-8301, USA.
authors.forename: Sangwon
authors.initials: S
authors.lastname: Chung
authors.forename: Nilesh P
authors.initials: NP
authors.lastname: Ingle
authors.forename: Gerardo A
authors.initials: GA
authors.lastname: Montero
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Martin W
authors.initials: MW
authors.lastname: King
mesh_terms: D020341:Absorbable Implants; D000042:Absorption; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001808:Blood Vessels / Q000166:cytology / Q000254:growth & development*; D049109:Cell Proliferation; D002470:Cell Survival / Q000502:physiology; D020724:Elastomers / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D006358:Hot Temperature; D008422:Materials Testing; D051379:Mice; D041681:NIH 3T3 Cells; D012399:Rotation; D023822:Tissue Engineering / Q000295:instrumentation*; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D020724:Elastomers