Surface modification of implanted cardiovascular metal stents: From antithrombosis and antirestenosis to endothelialization

Zhang, Kun; Liu, Tao; Li, Jingan; Chen, Junying; Wang, Jian; Huang, Nan

doi:10.1002/jbm.a.34714

Cited by 83 publications

(61 citation statements)

References 257 publications

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“…Various surface treatments have been adopted, including mechanical and electrochemical treatments [12], chemical etching, heat treatments, conventional and plasma ion immersion implantation [13], laser and electron-beam irradiation and application of bioactive surfaces [14]. Kun Zhang et al provided an in-depth review of various vascular stent surface modifications and their role on enhancing biological properties by primarily focusing on endothelialization on stent materials [15]. …”

Section: Introductionmentioning

confidence: 99%

Surface modification of Ni–Ti alloys for stent application after magnetoelectropolishing

Gill

Musaramthota

Munroe

et al. 2015

Materials Science and Engineering: C

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The constant demand for new implant materials and the multidisciplinary design approaches for stent applications have expanded vastly over the past decade. The biocompatibility of these implant materials is a function of their surface characteristics such as morphology, surface chemistry, roughness, surface charge and wettability. These surface characteristics can directly influence the material's corrosion resistance and biological processes such as endothelialization. Surface morphology affects the thermodynamic stability of passivating oxides, which renders corrosion resistance to passivating alloys. Magnetoelectropolishing (MEP) is known to alter the morphology and composition of surface films, which assist in improving corrosion resistance of Nitinol alloys. This work aims at analyzing the surface characteristics of MEP Nitinol alloys by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The wettability of the alloys was determined by contact angle measurements and the mechanical properties were assessed by Nanoindentation. Improved mechanical properties were observed with the addition of alloying elements. Cyclic potentiodynamic polarization tests were performed to determine the corrosion susceptibility. Further, the alloys were tested for their cytotoxicity and cellular growth with endothelial cells. Improved corrosion resistance and cellular viability were observed with MEP surface treated alloys.

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Section: Introductionmentioning

confidence: 99%

Surface modification of Ni–Ti alloys for stent application after magnetoelectropolishing

Gill

Musaramthota

Munroe

et al. 2015

Materials Science and Engineering: C

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“…Compared with polymer materials, metallic stents exhibit stable performance and therefore can provide preferable supporting strength. Nitinol (Ni-Ti), stainless steel (316L SS), cobalt-chromium (Co-Cr) alloy, tantalum (Ta), pure iron (Fe), platinum-iridium (Pt-Ir) alloy, and magnesium (Mg) alloys are the metallic biomaterials used for manufacturing stents5. Among these metallic stent materials, pure Fe and Mg alloys are the two metals that have been used for making biodegradable coronary stents6.…”

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confidence: 99%

Novel Ti-Ta-Hf-Zr alloys with promising mechanical properties for prospective stent applications

Lin

Ozan

et al. 2016

Sci Rep

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Titanium alloys are receiving increasing research interest for the development of metallic stent materials due to their excellent biocompatibility, corrosion resistance, non-magnetism and radiopacity. In this study, a new series of Ti-Ta-Hf-Zr (TTHZ) alloys including Ti-37Ta-26Hf-13Zr, Ti-40Ta-22Hf-11.7Zr and Ti-45Ta-18.4Hf-10Zr (wt.%) were designed using the d-electron theory combined with electron to atom ratio (e/a) and molybdenum equivalence (Moeq) approaches. The microstructure of the TTHZ alloys were investigated using optical microscopy, XRD, SEM and TEM and the mechanical properties were tested using a Vickers micro-indenter, compression and tensile testing machines. The cytocompatibility of the alloys was assessed using osteoblast-like cells in vitro. The as-cast TTHZ alloys consisted of primarily β and ω nanoparticles and their tensile strength, yield strength, Young’s modulus and elastic admissible strain were measured as being between 1000.7–1172.8 MPa, 1000.7–1132.2 MPa, 71.7–79.1 GPa and 1.32–1.58%, respectively. The compressive yield strength of the as-cast alloys ranged from 1137.0 to 1158.0 MPa. The TTHZ alloys exhibited excellent cytocompatibility as indicated by their high cell viability ratios, which were close to that of CP-Ti. The TTHZ alloys can be anticipated to be promising metallic stent materials by virtue of the unique combination of extraordinarily high elastic admissible strain, high mechanical strength and excellent biocompatibility.

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“…Endothelialization of stents following implantation is a crucial step in healing of injury sites 14 , and as such, we investigated the effect of PPACK-NP on endothelial proliferation. Thrombin has previously been shown to promote wound healing through generation of VEGF, and with inhibition of thrombin being potentially detrimental to endothelialization.…”

Section: Discussionmentioning

confidence: 99%

“…Specific anti-thrombotic surface modifications with the addition of heparin and bivalirudin have shown promise in prior studies. 14,22 Of note, Zilver PTX was recently approved and is the first drug-eluting stent approved for treatment of peripheral arterial disease. 23 Unfortunately, drug-eluting devices are plagued by early thrombosis and require prolonged dual antiplatelet therapy with its attendant bleeding risks and costs.…”

Section: Discussionmentioning

confidence: 99%

Antithrombin nanoparticles inhibit stent thrombosis in ex vivo static and flow models

Palekar

Vemuri

Marsh

et al. 2016

Journal of Vascular Surgery

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Introduction Despite significant advances in intravascular stent technology, safe prevention of stent thrombosis over prolonged periods after initial deployment persists as a medical need to reduce device failure. The objective of this project was to assess the potential of perfluorocarbon nanoparticles conjugated with the direct thrombin inhibitor D-phenylalanyl-L-prolyl-L-arginyl chloromethylketone (PPACK-NP) to inhibit stent thrombosis. Methods In a static model of stent thrombosis, 3 mm × 3 mm pieces of stainless steel coronary stents were cut and adsorbed with thrombin to create a procoagulant surface that would facilitate thrombus development. Following treatment with PPACK-NP or control NP, stents were exposed to platelet poor plasma (PPP) or platelet rich plasma (PRP) for set time points up to 60 minutes. Measurements of final clot weight in grams were utilized for assessing the effect of nanoparticle treatment on limiting thrombosis. Additionally, groups of stents were exposed to flowing plasma containing various treatments (saline, free PPACK, control NP and PPACK-NP) and generated thrombi were stained and imaged to investigate the treatment effects of PPACK-NP under flow conditions. Results The static model of stent thrombosis utilized in this study indicated a significant reduction in thrombus deposition with PPACK-NP treatment (0.00067 ± 0.00026g, N=3) compared to control NP (0.0098 ± 0.0015g, N=3, p = 0.026) in PPP. Exposure to PRP demonstrated similar effects with PPACK-NP treatment (0.00033 ± 0.00012g, N=3) versus control NP treatment (0.0045 ± 0.00012g, N=3, p = 0.000017). In additional studies, stents were exposed to both platelet rich plasma pretreated with vorapaxar and PPACK-NP, which illustrated adjunctive benefit to oral platelet inhibitors for prevention of stent thrombosis. Additionally, an in vitro model of stent thrombosis under flow conditions established that PPACK-NP treatment significantly inhibited thrombus deposition on stents. Conclusion This study demonstrates that anti-thrombin perfluorocarbon nanoparticles exert marked focal anti-thrombin activity to prevent intravascular stent thrombosis and occlusion.

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Surface modification of implanted cardiovascular metal stents: From antithrombosis and antirestenosis to endothelialization

Cited by 83 publications

References 257 publications

Surface modification of Ni–Ti alloys for stent application after magnetoelectropolishing

Surface modification of Ni–Ti alloys for stent application after magnetoelectropolishing

Novel Ti-Ta-Hf-Zr alloys with promising mechanical properties for prospective stent applications

Antithrombin nanoparticles inhibit stent thrombosis in ex vivo static and flow models

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