A small diameter, fibrous vascular conduit generated from a poly(ester urethane)urea and phospholipid polymer blend.
The thrombotic and hyperplastic limitations associated with synthetic small diameter vascular grafts have generated sustained interest in finding a tissue engineering solution for autologous vascular segment generation in situ. One approach is to place a biodegradable scaffold at the site that would provide acute mechanical support while vascular tissue develops. To generate a scaffold that possessed both non-thrombogenic character and mechanical properties appropriate for vascular tissue, a biodegradable poly(ester urethane)urea (PEUU) and non-thrombogenic bioinspired phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine-co-methacryloyloxyethyl butylurethane) (PMBU) were blended at PMBU weight fractions of 0-15% and electrospun to create fibrous scaffolds. The composite scaffolds were flexible with breaking strains exceeding 300%, tensile strengths of 7-10MPa and compliances of 2.9-4.4 x 10(-4) mmHg(-1). In vitro platelet deposition on the scaffold surfaces significantly decreased with increasing PMBU content. Rat smooth muscle cell proliferation was also inhibited on PEUU/PMBU blended scaffolds with greater inhibition at higher PMBU content. Fibrous vascular conduits (1.3mm inner diameter) implanted in the rat abdominal aorta for 8 weeks showed greater patency for grafts with 15% PMBU blending versus PEUU without PMBU (67% versus 40%). A thin neo-intimal layer with endothelial coverage and good anastomotic tissue integration was seen for the PEUU/PMBU vascular grafts. These results are encouraging for further evaluation of this technique in larger diameter applications for longer implant periods.
Hong
Yi
Y
McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA.
Ye
Sang-Ho
SH
Nieponice
Alejandro
A
Soletti
Lorenzo
L
Vorp
David A
DA
Wagner
William R
WR
D000818:Animals; D001792:Blood Platelets / Q000201:enzymology; D002448:Cell Adhesion; D002478:Cells, Cultured; D004583:Electrons; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D010743:Phospholipids / Q000737:chemistry*; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry*; D012756:Sheep
D008689:Methacrylates; D010743:Phospholipids; D011091:Polyesters; C497893:poly(ester urethane)urea; D010767:Phosphorylcholine; C070638:2-methacryloyloxyethyl phosphorylcholine