2024/08/24 by Axel Rentzsch, Eva Metz, Ruben Mühl‐Benninghaus +16 · 1 voice
Materials Science · Medicine · #Anodic Oxide Films and Nanostructures #Coronary Interventions and Diagnostics #Shape Memory Alloy Transformations
paper · doi:10.1016/j.carrev.2024.08.017
openalex publication_date 2024/08/24 · openalex created_date 2024/08/25 · openalex updated_date 2026/07/22
Intima proliferation and in-stent restenosis is a challenging situation in interventional treatment of small vessel obstruction. Al/Al 2 O 3 nanowires have been shown to accelerate vascular endothelial cell proliferation and migration in vitro, while suppressing vascular smooth muscle cell growth. Moreover, surface modification of Al/Al 2 O 3 nanowires with poly[bis(2,2,2-trifluoromethoxy)phosphazene (PTFEP) coating enables further advantages such as reduced platelet adhesion. Therefore, the study's goal was to compare the biocompatibility of novel Al/Al 2 O 3 + PTFEP coated nanowire bare-metal stents to uncoated control stents in vivo using optical coherence tomography (OCT), quantitative angiography and histomorphometric assessment. 15 Al/Al 2 O 3 + PTFEP coated and 19 control stents were implanted in the cervical arteries of 9 Aachen minipigs. After 90 days, in-stent stenosis, thrombogenicity, and inflammatory response were assessed. Scanning electron microscopy was used to analyse the stent surface. OCT analysis revealed that neointimal proliferation in Al/Al 2 O 3 + PTFEP coated stents was significantly reduced compared to control stents. The neointimal area was 1.16 ± 0.77 mm 2 in Al/Al 2 O 3 + PTFEP coated stents vs. 1.98 ± 1.04 mm 2 in control stents ( p = 0.004), and the neointimal thickness was 0.28 ± 0.20 vs. 0.47 ± 0.10 ( p = 0.003). Quantitative angiography showed a tendency to less neointimal growth in coated stents. Histomorphometry showed no significant difference between the two groups and revealed an apparent inflammatory reaction surrounding the stent struts. At long-term follow-up, Al/Al 2 O 3 + PTFEP coated stents placed in peripheral arteries demonstrated good tolerance with no treatment-associated vascular obstruction and reduced in-stent restenosis in OCT. These preliminary in vivo findings indicate that Al/Al 2 O 3 + PTFEP coated nanowire stents may have translational potential to be used for the prevention of in-stent restenosis. • Nanowire surfaces promote endothelial cell growth and reduce platelet adhesion in vitro. • Al/Al 2 O 3 + PTFEP nanowire coated stents can be used in vivo safely and effectively. • Surface modification showed lower intima proliferation and re-stenosis observed in OCT. • Nano-modification of small vascular implants will improve the application range.