Impact of Tungsten Disulfide Nanotubes on the crystallization of poly(l-lactide) for thinner and stronger bioresorbable vascular scaffolds (BVS)

ORAL

Abstract

Bioresorbable Vascular Scaffolds (BVSs) are transient implants that can revolutionize the treatment of coronary heart disease by restoring vasomotion in the occluded artery. However, the adoption of pure poly L-lactide (PLLA) BVSs is hindered by their thickness (150µm), which is nearly twice that of metal stents. A thinner scaffold is easier to implant and can treat smaller lesions. A BVS reinforced with biocompatible Tungsten Disulfide (WS2) nanotubes (WSNTs) offers a solution towards a thinner, stronger BVS. To understand the impact of WSNTs on PLLA during processing, we subject PLLA and PLLA-WS2 (0.05wt%, 0.1wt%) to a shear pulse and probe the evolution of birefringence in real time. We discovered that WSNTs favor the formation of “shish-kebabs” in PLLA. Thread-like precursors that grow into shish are characterized by an upturn in birefringence during flow and kebabs are detected by an increase in birefringence after cessation of flow. Intriguingly, PLLA and PLLA-WS2 (0.05%) lack an oriented skin along the flow-direction, but possess a skin normal to the flow-direction. However, PLLA-WS2 (0.1%) exhibits a skin along both directions. We are investigating further upon this unexpected morphology and the role of WSNTs in enabling a thinner, stronger BVS.

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Presenters

  • Tiziana Di Luccio

    • Chemistry and Chemical Engineering, California Institute of Technology

Authors

  • Tiziana Di Luccio

    • Chemistry and Chemical Engineering, California Institute of Technology

  • Karthik Ramachandran

    • CCE, California Institute of Technology
    • Caltech
    • Chemistry and Chemical Engineering, California Institute of Technology

  • Zach Zixuan Shao

    • Biology and Biological Engineering, California Institute of Technology

  • Loredana Tammaro

    • Division for Sustainable Materials, ENEA Italian national agency for new technlogies, energy and sustainable economic development

  • Carmela Borriello

    • Division for Sustainable Materials, ENEA Italian national agency for new technlogies, energy and sustainable economic development

  • Fausta Loffredo

    • Division for Sustainable Materials, ENEA Italian national agency for new technlogies, energy and sustainable economic development

  • Fulvia Villani

    • Division for Sustainable Materials, ENEA Italian national agency for new technlogies, energy and sustainable economic development

  • Francesca Di Benedetto

    • Division for Sustainable Materials, ENEA Italian national agency for new technlogies, energy and sustainable economic development

  • Sandy Leung

    • International Institute for Nanocomposites Manufacturing (IINM) Warwick Manufacturing Group (WMG), University of Warwick

  • Tony McNally

    • International Institute for Nanocomposites Manufacturing (IINM) Warwick Manufacturing Group (WMG), University of Warwick

  • David Boyd

    • Division of Physics, Mathematics & Astronomy, California Institute of Technology

  • Julie Kornfield

    • Chemical Engineering, Caltech
    • California Institute of Technology
    • CCE, California Institute of Technology
    • Chemistry and Chemical Engineering, California Institute of Technology
    • Caltech