title: Tubular nanofiber scaffolds for tissue engineered small-diameter vascular grafts.
abstract: Quick establishment of a confluent and stable endothelial cells (ECs) layer in the lumen of vascular grafts is critical for long-term patency of small-diameter vascular grafts. The objective of the study was to fabricate tubular nanofiber scaffolds, incorporate ECs onto the lumen of the scaffolds, and establish an animal model to prove the basic concept of using the scaffolds as vascular grafts. Poly(L-lactic acid)-co-poly(epsilon-caprolactone) P(LLA-CL 70:30) tubular nanofiber scaffolds were fabricated by electrospinning onto a rotating mandrel. Collagen was coated onto the scaffolds after air plasma treatment. Structure and mechanical property of the scaffolds were studied by scanning electron microscopy and tensile stress measurement, respectively. Human coronary artery endothelial cells (HCAECs) were rotationally seeded onto the lumen of the scaffolds at the speed of 6 rpm for 4 h through a customized seeding device, followed with static culture. Results showed evenly distributed and well-spread HCAECs throughout the lumen of the scaffold from 1 day onward to 10 days after seeding. Further, HCAECs maintained phenotypic expression of PECAM-1. To prove the basic concept of using the scaffolds as vascular grafts, acellular tubular P(LLA-CL) nanofiber scaffolds (inner diameter 1 mm) were implanted into rabbits to replace the inferior superficial epigastric veins. Results showed the scaffolds sustained the surgical process, kept the structure integrity, and showed the patency for 7 weeks.
authors.affiliation: Graduate Program in Bioengineering, National University of Singapore, Centre for Life Sciences No. 05-01, 28 Medical Drive, Singapore 117456. hewei@nus.edu.sg
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.forename: Zuwei
authors.initials: Z
authors.lastname: Ma
authors.forename: Wee Eong
authors.initials: WE
authors.lastname: Teo
authors.forename: Yi Xiang
authors.initials: YX
authors.lastname: Dong
authors.forename: Peter Ashley
authors.initials: PA
authors.lastname: Robless
authors.forename: Thiam Chye
authors.initials: TC
authors.lastname: Lim
authors.forename: Seeram
authors.initials: S
authors.lastname: Ramakrishna
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001807:Blood Vessel Prosthesis; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000166:cytology; D042783:Endothelial Cells / Q000166:cytology; D006801:Humans; D020007:Implants, Experimental; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry*; D011138:Polytetrafluoroethylene / Q000737:chemistry; D011817:Rabbits; D013718:Tensile Strength; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D011138:Polytetrafluoroethylene