Graeme Clark Collection

Permanent URI for this collection

Search Results

Now showing 1 - 2 of 2
  • Item
    Thumbnail Image
    Inhibition of smooth muscle cell adhesion and proliferation on heparin-doped polypyrrole
    Stewart, EM ; Liu, X ; Clark, GM ; Kapsa, RMI ; Wallace, GG (ELSEVIER SCI LTD, 2012-01)
    We have investigated the application of polypyrrole (pPy) as a material to influence neointimal cell behaviour. The physico-chemical properties of pPy doped with heparin (Hep), para-toluene sulfonate, poly(2-methoxyaniline-5-sulfonic acid) (pMAS) and nitrate ions were studied in addition to cell adhesion and proliferation studies of neointimal relevant cell lines cultured on the pPy substrates. Both smooth muscle (hSMC) and endothelial (hEC) cell types adhered and proliferated best on the smooth, hydrophilic pPy/pMAS material. Moreover, pPy/Hep is able to support the proliferation of hECs on the surface but inhibits hSMC proliferation after 4 days of culture. The inhibitory effect on hSMCs is most likely due to the well-known antiproliferative effect of heparin on hSMC growth. The results presented indicate that surface exposed heparin binds to the putative heparin receptor of hSMCs and is sufficient to inhibit proliferation. The application of galvanostatically synthesized pPy/Hep to stent surfaces presents a novel bioactive control mechanism to control neointimal cell growth.
  • Item
    Thumbnail Image
    Wet-Spun Biodegradable Fibers on Conducting Platforms: Novel Architectures for Muscle Regeneration
    Razal, JM ; Kita, M ; Quigley, AF ; Kennedy, E ; Moulton, SE ; Kapsa, RMI ; Clark, GM ; Wallace, GG (WILEY-V C H VERLAG GMBH, 2009-11-09)
    Abstract Novel biosynthetic platforms supporting ex vivo growth of partially differentiated muscle cells in an aligned linear orientation that is consistent with the structural requirements of muscle tissue are described. These platforms consist of biodegradable polymer fibers spatially aligned on a conducting polymer substrate. Long multinucleated myotubes are formed from differentiation of adherent myoblasts, which align longitudinally to the fiber axis to form linear cell‐seeded biosynthetic fiber constructs. The biodegradable polymer fibers bearing undifferentiated myoblasts can be detached from the substrate following culture. The ability to remove the muscle cell‐seeded polymer fibers when required provides the means to use the biodegradable fibers as linear muscle‐seeded scaffold components suitable for in vivo implantation into muscle. These fibers are shown to promote differentiation of muscle cells in a highly organized linear unbranched format in vitro and thereby potentially facilitate more stable integration into recipient tissue, providing structural support and mechanical protection for the donor cells. In addition, the conducting substrate on which the fibers are placed provides the potential to develop electrical stimulation paradigms for optimizing the ex vivo growth and synchronization of muscle cells on the biodegradable fibers prior to implantation into diseased or damaged muscle tissue.