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In vivo performance of a phospholipid‐coated bioerodable elastomeric graft for small‐diameter vascular applications
Author(s) -
Soletti Lorenzo,
Nieponice Alejandro,
Hong Yi,
Ye SangHo,
Stankus John J.,
Wagner William R.,
Vorp David A.
Publication year - 2011
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.32997
Subject(s) - materials science , in vivo , biomedical engineering , lumen (anatomy) , tissue engineering , phosphorylcholine , elastin , surgery , chemistry , pathology , medicine , biology , biochemistry , microbiology and biotechnology
There remains a great need for vascular substitutes for small‐diameter applications. The use of an elastomeric biodegradable material, enabling acute antithrombogenicity and long‐term in vivo remodeling, could be beneficial for this purpose. Conduits (1.3 mm internal diameter) were obtained by electrospinning biodegradable poly(ester urethane)urea (PEUU), and by luminally immobilizing a non‐thrombogenic, 2‐methacryloyloxyethyl phosphorylcholine (MPC) copolymer. Platelet adhesion was characterized in vitro after contact with ovine blood. The conduits were implanted as aortic interposition grafts in the rat for 4, 8, 12, and 24 weeks. Surface treatment resulted in a 10‐fold decrease in platelet adhesion compared to untreated material. Patency at 8 weeks was 92% for the coated grafts compared to 40% for the non‐coated grafts. Histology at 8 and 12 weeks demonstrated formation of cellularized neotissue consisting of aligned collagen and elastin. The lumen of the grafts was confluent with cells qualitatively aligned in the direction of blood flow. Immunohistochemistry suggested the presence of smooth muscle cells in the medial layer of the neotissue and endothelial cells lining the lumen. Mechanically, the grafts were less compliant than rat aortas prior to implantation (4.5 ± 2.0 × 10 −4 mmHg −1 vs. 14.2 ± 1.1 × 10 −4 mmHg −1 , respectively), then after 4 weeks in vivo they approximated native values, but subsequently became stiffer again at later time points. The novel coated grafts exhibited promising antithrombogenic and mechanical properties for small‐diameter arterial revascularization. Further evaluation in vivo will be required to demonstrate complete remodeling of the graft into a native‐like artery. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.