Pu F R, Williams R L, Markkula T K, Hunt J A
Clinical Engineering Department, University of Liverpool, UK.
Biomaterials. 2002 Jun;23(11):2411-28. doi: 10.1016/s0142-9612(01)00377-5.
The aim of this study was to evaluate the expression of adhesion molecules on the surface of human endothelial cells in response to the systematic variation in materials properties by the ammonia plasma modification of polyethylene terephthalate (PET) and polytetrafluorethylene (PTFE). These adhesion molecules act as mediators of cell adhesion, play a role in the modulation of cell adhesion on biomaterials and therefore condition the response of tissues to implants. First and second passage human umbilical vein endothelial cells (HUVECs) were cultured on plasma treated and untreated PET and PTFE. HUVECs grown on polystyrene tissue culture coverslips and HUVECs stimulated with tumour necrosis factor (TNF-alpha) were used as controls. After 1 day and 7 days, the expression of adhesion molecules platelet endothelial cell adhesion molecule-1 (PECAM-1), intercellular adhesion molecule-1 (ICAM-1), Integrin alphavbeta3, vascular cell adhesion molecule-1 (VCAM-1), E-selectin, P-selectin and L-selectin were evaluated using flow cytometry and immunohistochemistry. There was a slight increase in positive cell numbers expressing the adhesion molecules ICAM-1 and VCAM-1 on plasma treated PET and PTFE. A significant increase in E-selectin positive cells on untreated PTFE was demonstrated after 7 days. Stimulation with TNF-alpha demonstrated a significant increase in the proportion of ICAM-1. VCAM-1 and E-selectin positive cells. Almost all cells expressed PECAM-1 and integrin alphavbeta3, on both materials and controls but did not express P- and L-selectin on any surface. When second passage cells were used, the expression of the adhesion molecules ICAM-1 and VCAM-1 was markedly increased on all surfaces but not with TNF-alpha. These significant differences were not observed in other adhesion molecules. These results were supported by immunohistochemical studies. The effects of plasma treated PET and PTFE on cell adhesion and proliferation was also studied. There was a 1.3-fold increase in cell numbers adhered on ammonia plasma treated PET compared to untreated PET and a 5.5-fold increase in cell numbers on treated PTFE compared to untreated PTFE after 1 day. This is significantly different when analysed statistically. After 7 days, cell number increased significantly on all surfaces compared to 1 day, except for untreated PTFE which conversely reduced by 41%. Cell number on the surface of untreated PET was no different to treated PET on days 1 and 7 when second passage cells were used. The study has shown that the plasma treatment of PET and PTFE with ammonia improves the adhesion and growth of endothelial cells and slightly upregulates the expression of adhesion molecules. This surface modification should promote colonisation of an artificial vascular prosthesis by endothelial cells and make it less vulnerable to immune system cells of the recipient. In addition, it should be considered which passage of cells is used due to the different adhesion features of different passages of HUVECs on untreated PET.
本研究的目的是通过对聚对苯二甲酸乙二酯（PET）和聚四氟乙烯（PTFE）进行氨等离子体改性，评估材料性能的系统变化对人内皮细胞表面粘附分子表达的影响。这些粘附分子作为细胞粘附的介质，在调节生物材料上的细胞粘附中发挥作用，因此决定了组织对植入物的反应。将第一代和第二代人脐静脉内皮细胞（HUVECs）培养在经等离子体处理和未经处理的PET和PTFE上。以生长在聚苯乙烯组织培养盖玻片上的HUVECs和用肿瘤坏死因子（TNF-α）刺激的HUVECs作为对照。在1天和7天后，使用流式细胞术和免疫组织化学评估粘附分子血小板内皮细胞粘附分子-1（PECAM-1）、细胞间粘附分子-1（ICAM-1）、整合素αvβ3、血管细胞粘附分子-1（VCAM-1）、E-选择素、P-选择素和L-选择素的表达。在经等离子体处理的PET和PTFE上，表达粘附分子ICAM-1和VCAM-1的阳性细胞数量略有增加。7天后，未处理的PTFE上E-选择素阳性细胞显著增加。用TNF-α刺激显示ICAM-1、VCAM-1和E-选择素阳性细胞的比例显著增加。几乎所有细胞在材料和对照上均表达PECAM-1和整合素αvβ3，但在任何表面均不表达P-和L-选择素。当使用第二代细胞时，所有表面上粘附分子ICAM-1和VCAM-1的表达均显著增加，但TNF-α刺激后无此现象。在其他粘附分子中未观察到这些显著差异。这些结果得到了免疫组织化学研究的支持。还研究了经等离子体处理的PET和PTFE对细胞粘附和增殖的影响。与未处理的PET相比，氨等离子体处理的PET上粘附的细胞数量增加了1.3倍，与未处理的PTFE相比，处理后的PTFE上的细胞数量增加了5.5倍。1天后，经统计学分析，这有显著差异。7天后，与1天相比，所有表面上的细胞数量均显著增加，但未处理的PTFE相反减少了41%。当使用第二代细胞时，在第1天和第7天，未处理的PET表面上的细胞数量与处理后的PET无差异。该研究表明，用氨对PET和PTFE进行等离子体处理可改善内皮细胞的粘附和生长，并轻微上调粘附分子的表达。这种表面改性应促进内皮细胞对人工血管假体的定植，并使其不易受到受体免疫系统细胞的攻击。此外，由于不同代次的HUVECs在未处理的PET上具有不同的粘附特征，因此应考虑使用哪一代细胞。
