Novel polymers to encourage rapid recovery of arterial function following coronary stenting

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2012
Thesis identifier
  • T13229
Qualification Level
Qualification Name
Department, School or Faculty
  • Intravascular stenting in conjunction with balloon angioplasty is standard practice in percutaneous coronary interventions. Despite widespread acceptance of this procedure associated limitations remain, notably in-stent restenosis, delayed vessel healing and late-stent thrombosis. Normal arterial function is preserved in a healthy coronary artery by the endothelium, a single layer of cells which lines the lumen protecting against thrombus formation and helping to control vascular tone. Following coronary stenting the endothelium is destroyed, exposing the underlying smooth muscle cells to a powerful inflammatory stimulus. This can cause smooth muscle cell hyperplasia which thickens the neointima thus narrowing the lumen of the artery, which may then require repeat revascularisation. Existing Drug-Eluting Stents (DES) release cytostatic drugs which inhibit smooth muscle cell proliferation. Despite positive indications from initial clinical trials, an associated morbidity has emerged attributed to impaired re-endothelialisation due to negative effects of eluted drugs and the unfavourable growth environment provided by the polymer. This project investigates polypyrrole, a non-toxic conducting polymer, as a novel coating more conducive to re-endothelialisation for use in a next generation DES. Porcine primary endothelial and smooth muscle cells, harvested and cultured in-vitro on a series of polypyrrole surfaces, were assessed in terms of confluence, viability, adherence, morphology and migration. Polypyrrole was synthesised by electropolymerisation onto medical grade stainless steel plates. In these circumstances topography remained consistent despite variation in synthesis techniques. However, an apparent influence remained of the polypyrrole and dopant drug on cell growth and morphology. Proliferation of endothelial and smooth muscle cells, displaying characteristic morphologies, was observed on polypyrrole, with low LDH levels indicating a high level of viability. This preliminary study demonstrates the considerable potential displayed by polypyrrole for use in a vascular environment and supports further research into the development of a polypyrrole-based drug-polymer for use in coronary stenting.
Resource Type
Date Created
  • 2012
Former identifier
  • 966998