Applied Science and Technology Department (DISAT), Polytechnic of Turin, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
Anal Bioanal Chem. 2013 Jan;405(1):321-9. doi: 10.1007/s00216-012-6449-x. Epub 2012 Oct 9.
The vast majority of stent thrombosis occurs in the acute and sub-acute phases and is more common in patients with acute coronary syndromes, due to the thrombotic milieu where stent struts are positioned. Stent thrombosis is likely due to incomplete tissue coverage of metallic stents as the contact between metallic stents and blood elements may lead to platelet adhesion and trigger vessel thrombosis. If a stent is covered after 7 days, the risk that it will be found uncovered at later stages is very low (<1%). In this article, we demonstrate that diamond-like carbon (DLC) coatings, deposited by physical vapour deposition, promote rapid endothelisation of coronary stent devices, with very low platelets activation, reducing thrombotic clots. We relate these behaviours to the surface and bulk material properties of the DLC films, subjected to a comprehensive chemico-physical characterisation using several techniques (X-ray photoelectron spectroscopy, atomic force microscopy, field-emission scanning electron microscope, transmission electron microscopy combined with electron energy loss spectroscopy, Raman and dispersive X-ray spectroscopy). In vivo studies, conducted on 24 pigs, have shown complete endothelisation after 7 days, with no fibrin mesh and with only rare monocytes scattered on the endothelial layer while 30 and 180 days tests have shown reduced inflammatory activation and a complete stabilisation of the vessel healing, with a minimal neointimal proliferation. The integral and permanent DLC film coating improves haemo- and bio-compatibility and leads to an excellent early vessel healing of the stent whilst the extremely thin strut thickness reduces the amount of late neointima and consequently the risk of late restenosis. These data should translate into a reduced acute and sub-acute stent thrombosis.
绝大多数支架血栓形成发生在急性和亚急性阶段，在急性冠脉综合征患者中更为常见，这是由于支架支柱所处的血栓环境所致。支架血栓形成可能是由于金属支架的组织覆盖不完全，因为金属支架与血液成分的接触可能导致血小板黏附并引发血管血栓形成。如果支架在 7 天后被覆盖，那么在以后的阶段发现未被覆盖的风险非常低（<1%）。在本文中，我们证明了通过物理气相沉积沉积的类金刚石碳（DLC）涂层可促进冠状动脉支架设备的快速内皮化，同时血小板激活非常低，减少血栓形成。我们将这些行为与 DLC 薄膜的表面和体材料特性联系起来，使用几种技术（X 射线光电子能谱、原子力显微镜、场发射扫描电子显微镜、透射电子显微镜结合电子能量损失光谱、拉曼和漫反射 X 射线光谱）对其进行了全面的化学物理特性分析。在 24 头猪进行的体内研究表明，在 7 天后完全内皮化，没有纤维蛋白网，内皮层上只有少数单核细胞散布，而在 30 天和 180 天的测试中，炎症激活减少，血管愈合完全稳定，新生内膜增殖最小。完整且永久的 DLC 薄膜涂层提高了血液和生物相容性，并导致支架的早期血管愈合良好，而极薄的支柱厚度减少了晚期新生内膜的数量，从而降低了晚期再狭窄的风险。这些数据应转化为减少急性和亚急性支架血栓形成。
