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Research Papers

Fabrication and Testing of Planar Stent Mesh Designs Using Carbon-Infiltrated Carbon Nanotubes

[+] Author and Article Information
Anton Bowden

Department of Mechanical Engineering,
Brigham Young University,
Provo, UT 84602

Manuscript received February 15, 2013; final manuscript received September 23, 2013; published online October 17, 2013. Assoc. Editor: Shaurya Prakash.

J. Nanotechnol. Eng. Med 4(2), 020903 (Oct 17, 2013) (7 pages) Paper No: NANO-13-1007; doi: 10.1115/1.4025598 History: Received February 15, 2013; Revised September 23, 2013

This paper explores and demonstrates the potential of using pyrolytic carbon as a material for coronary stents. Stents are commonly fabricated from metal, which has worse biocompatibilty than many polymers and ceramics. Pyrolytic carbon, a ceramic, is currently used in medical implant devices due to its preferable biocompatibility properties. Micropatterned pyrolytic carbon implants can be created by growing carbon nanotubes (CNTs), and then filling the space between with amorphous carbon via chemical vapor deposition (CVD). We prepared multiple samples of two different stent-like flexible mesh designs and smaller cubic structures out of carbon-infiltrated carbon nanotubes (CI-CNT). Tension loads were applied to expand the mesh samples and we recorded the forces at brittle failure. The cubic structures were used for separate compression tests. These data were then used in conjunction with a nonlinear finite element analysis (FEA) model of the stent geometry to determine Young's modulus and maximum fracture strain in tension and compression for each sample. Additionally, images were recorded of the mesh samples before, during, and at failure. These images were used to measure an overall percent elongation for each sample. The highest fracture strain observed was 1.4% and Young's modulus values confirmed that the material was similar to that used in previous carbon-infiltrated carbon nanotube work. The average percent elongation was 86% with a maximum of 145%. This exceeds a typical target of 66%. The material properties found from compression testing show less stiffness than the mesh samples; however, specimen evaluation reveals poorly infiltrated samples.

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References

Schmidt, W., Lanzer, P., Behrens, P., Topoleski, L., and Schmitz, K.-P., 2009, “A Comparison of the Mechanical Performance Characteristics of Seven Drug-Eluting Stent Systems,” Cathet. Cardiovasc. Interv., 73, pp. 350–360. [CrossRef]
Howell, L. L., 2001, Compliant Mechanisms, Wiley Interscience, New York.
Hansi, C., Arab, A., Rzany, A., Ahrens, I., Bode, C., and Hehrlein, C., 2009, “Differences of Platelet Adhesion and Thrombus Activation on Amorphous Silicon Carbide, Magnesium Alloy, Stainless Steel, and Cobalt Chromium Stent Surfaces,” Cathet. Cardiovasc. Inter., 73, pp. 488–496. [CrossRef]
Serruys, P., Kutrykm, M., and Ong, A., 2006, “Coronary-Artery Stents,” New Engl. J. Med., 354, pp. 483–495. [CrossRef]
Serruys, P., Luijten, H., Beatt, K., Geuskens, R., de Feyter, P., van den Brand, M., Reiber, J., ten Katen, H., van Es, G., and Hugenholtz, P., 1988, “Incidence of Restenosis After Successful Coronary Angioplasty: A Time-Related Phenomenon. A Quantitative Angiographic Study in 342 Consecutive Patients at 1, 2, 3, and 4 Months,” Circulation, 77, pp. 361–371. Available at: http://circ.ahajournals.org/content/77/2/361 [CrossRef] [PubMed]
Iakovou, I., Schmidt, T., Bonizzoni, E., Ge, L., Sangiorgi, G. M., Stankovic, G., Airoldi, F., Chieffo, A., Montorfano, M., Carlino, M., Michev, I., Corvaja, N., Briguori, C., Gerckens, U., Grube, E., and Colombo, A., 2005, “Incidence, Predictors, and Outcome of Thrombosis After Successful Implantation of Drug-Eluting Stents,” J. Am. Med. Assoc., 293(17), pp. 2126–2130. [CrossRef]
Ratner, B. D., Hoffman, A. S., Shoen, F. J., and Lemons, J. E., 2004, Biomaterials Science: An Introduction to Materials in Medicine, Elsevier Academic Press, Oxford, UK.
Pesakova, V., Klezl, Z., Balik, M., and Adam, M., 2000, “Biomechanical and Biological Properties of the Implant Material Carbon-Carbon Composite Covered With Pyrolytic Carbon,” J. Mater. Sci.: Mater. Med., 11, pp. 793–798. [CrossRef] [PubMed]
Stary, V., Bacakova, L., Hornik, J., and Chmelik, V., 2003, “Bio-Compatibility of the Surface Layer of Pyrolytic Graphite,” Thin Solid Films, 433, pp. 191–198. [CrossRef]
Antoniucci, D., Bartorelli, A., Valenti, R., Montorsi, P., Santor, G. M., Fabbiocchi, F., Bolognese, L., Loaldi, A., Trapani, M., Trabattoni, D., Moschi, G., and Galli, S., 2000, “Clinical and Angiographic Outcome After Coronary Arterial Stenting With the Carbostent,” Am. J. Cardiol., 85, pp. 821–825. [CrossRef] [PubMed]
Kellie, B. M., Silleck, A. C., Bellman, K., Snodgrass, R., and Prakash, S., 2013, “Deposition of Few-Layered Graphene in a Microcombustor on Copper and Nickel Substrates,” RSC Adv., 3, pp. 7100–7105. [CrossRef]
Torbensen, K., Iruthayaraj, J., Ceccato, M., Kongsfelt, M., Breitenbach, T., Pedersen, S. U., and Daasbjerg, K., 2012, “Conducting and Ordered Carbon Films Obtained by Pyrolysis of Covalently Attached Polyphenylene and Polyanthracene Layers on Silicon Substrates,” J. Mater. Chem., 22, pp. 18172–18180. [CrossRef]
Cook, S. D., Beckenbaugh, R. D., Redondo, J., Popich, L. S., Klawitter, J. J., and Linscheid, R. L., 1999, “Long Term Follow-up of Pyrolytic Carbon Metacarpophalangeal Inplants,” J. Bone Joint Surg., 81, pp. 635–648.
Wall, L. B., and Stern, P. J., 2013, “Clinical and Radiographic Outcomes of Metacarpophalangeal Joint Pyrolytic Carbon Arthroplasty for Osteoarthritis,” J. Hand Surg., 38, pp. 537–543. [CrossRef]
Behzadi, S., Imani, M., Yousefi, M., Galinetto, P., Simchi, A., Amiri, H., Stroeve, P., and Mahmoudi, M., 2012, “Pyrolytic Carbon Coating for Cytocompatibility of Titanium Oxide Nanoparticles: A Promising Candidate for Medical Applications,” Nanotechnology, 23, p. 045102. [CrossRef] [PubMed]
Hutchison, D. N., Morrill, N. B., Aten, Q., Turner, B. W., Jensen, B. D., Vanfleet, R. R., and Davis, R. C., 2010, “Carbon Nanotubes as a Framework for High-Aspect-Ratio MEMS Fabrication,” J. Microelectromech. Syst., 19, pp. 75–82. [CrossRef]
Mazloumi, M., Shadmehr, S., Rangom, Y., Nazar, L. F., and Tang, X. S., 2013, “Fabrication of Three-Dimensional Carbon Nanotube and Metal Oxide Hybrid Mesoporous Architectures,” ACS Nano, 7(5), pp. 4281–4288. [CrossRef] [PubMed]
Fazio, W. C., Lund, J. M., Wood, T. S., Jensen, B. D., Davis, R. C., and Vanfleet, R. R., 2011, “Material Properties of Carbon-Infiltrated Carbon Nanotube-Templated Structures for Microfabrication of Compliant Mechanisms,” Proceedings of the ASME 2011 International Mechanical Engineering Congress & Exposition, ASME Paper No. IMECE2011-64168.
Auricchio, F., Di Loreto, M., and Sacco, E., 2001, “Finite-Element Analysis of a Stenotic Artery Revascularization Through a Stent Insertion,” Comput. Methods Biomech. Biomed. Eng., 4, pp. 249–263. [CrossRef]
Migliavacca, F., Petrini, L., Colombo, M., Auricchio, F., and Pietrabissa, R., 2002, “Mechanical Behavior of Coronary Stents Investigated Through the Finite Element Method,” J. Biomech., 35, pp. 803–811. [CrossRef] [PubMed]

Figures

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Fig. 1

Sample mesh designs configured to undergo large deflections. On the left is the curved design, and the rectangular design is on the right.

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Fig. 2

CNT-M process with carbon infiltration

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Fig. 3

Example of sample size comparison to a United States penny

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Fig. 4

Sample mesh example after KOH release and rinse

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Fig. 5

Planar mesh test setup with Instron and gripping fixtures

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Fig. 6

Camera view sample of images where measurements of deflection were taken

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Fig. 7

Typical force–deflection curve for the stent mesh tensile samples

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Fig. 8

Strain values as calculated from the ansys analyses. C stands for the curved design, while R stands for the rectangular design.

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Fig. 9

Modulus values as calculated from the ansys analyses. Labels are as in Fig. 8.

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Fig. 10

Percent elongation of each analyzed test cell. Labels are as in Fig. 8.

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Fig. 11

Plot showing compression samples in both directions

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Fig. 12

SEM image of broken transverse compression sample

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Fig. 13

SEM image of broken transverse compression sample with detail on infiltration quality, revealing multiple voids in the material

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