Imparting electroactivity to polycaprolactone fibers with heparin-doped polypyrrole: Modulation of hemocompatibility and inflammatory responses. (1st September 2015)

• Record Type: Journal Article
• Authors: Xiong, Gordon M.; Yuan, Shaojun; Wang, Jun Kit; Do, Anh Tuan; Tan, Nguan Soon; Yeo, Kiat Seng; Choong, Cleo
• Is Part Of: Acta biomaterialia. Volume 23(2015)
• Page Start: 240
• Page End: 249
• Publication Date: 2015-09-01
• Subjects: Polypyrrole -- Heparin -- Polycaprolactone -- Electrical stimulation -- Vascular grafts; Biomedical materials -- Periodicals; 610.28
• DOI: 10.1016/j.actbio.2015.05.003
• Languages: English
• ISSNs: 1742-7061

Abstract

Graphical abstract: Abstract: Hemocompatibility, anti-inflammation and anti-thrombogenicity of acellular synthetic vascular grafts remains a challenge in biomaterials design. Using electrospun polycaprolactone (PCL) fibers as a template, a coating of polypyrrole (PPy) was successfully polymerized onto the fiber surface. The fibers coated with heparin-doped PPy (PPy-HEP) demonstrated better electroactivity, lower surface resistivity (9–10-fold) and better anti-coagulation response (non-observable plasma recalcification after 30 min vs. recalcification at 8–9 min) as compared to fibers coated with pristine PPy. Red blood cell compatibility, measured by% hemolysis, was greatly improved on PPy-HEP-coated PCL in comparison to uncoated PCL (3.9 ± 2.1% vs. 22.1 ± 4.1%). PPy-HEP-coated PCL fibers also exhibited higher stiffness values (6.8 ± 0.9 MPa vs. 4.2 ± 0.8 MPa) as compared to PCL fibers, but similar tensile strengths. It was also observed that the application of a low alternating current led to a 4-fold reduction of platelet activation (as quantitated by CD62p expression) for the PPy-HEP-coated fibers as compared to non-stimulated conditions. In parallel, a reduction in the leukocyte adhesion to both pristine PPy-coated and PPy-HEP-coated fibers was observable with AC stimulation. Overall, a new strategy involving the use of hemocompatible conducting polymers and electrical stimulation to control thrombogenicity and inflammatory responses for synthetic vascular graft designs was demonstrated.