Seeger J M, Ingegno M D, Bigatan E, Klingman N, Amery D, Widenhouse C, Goldberg E P
Department of Surgery, University of Florida, Gainesville, USA.
J Vasc Surg. 1995 Sep;22(3):327-35; discussion 335-6. doi: 10.1016/s0741-5214(95)70148-6.
Stainless steel endovascular stents are inherently thrombogenic so that thrombus accumulates on these devices, leading to acute vessel occlusion. A potential solution to this problem is stent surface modification with hydrophilic polymers, which might limit platelet adhesion and reactivity.
N-vinylpyrrolidone (NVP) and potassium sulfopropyl acrylate (KSPA) hydrophilic monomers were gamma graft polymerized onto 1 cm2 stainless steel slabs and 4 mm Palmaz stainless steel stents. Surface characteristics of modified and plain stainless steel stents were then investigated with contact angle and x-ray photoelectron spectroscopy measurements, and in vitro and in vivo platelet reactivity was assessed as 111Indium platelet accumulation expressed as counts/min/cm2.
Surface modification of stainless steel slabs and stents with both NVP and KSPA hydrophilic polymers significantly reduced in vitro platelet adhesion (plain = 2249 +/- 723 counts/min/cm2, NVP = 428 +/- 156 counts/min/cm2, KSPA = 958 +/- 223 counts/min/cm2) and in vivo platelet accumulation after 1 hour of blood flow exposure (plain = 1407 +/- 796 counts/min/cm2, NVP = 426 +/- 175 counts/min/cm2, KSPA = 399 +/- 124 counts/min/cm2. In addition, platelet accumulation on modified stents indexed to plain stents was lowest in KSPA-modified stents (NVP = 79.3% +/- 31.7% of plain, KSPA = 51.2% +/- 36.2% of plain). Surface analysis confirmed surface grafting with both monomers, and SEM documented smoothing of the irregular surfaces of the stainless steel stents after grafting.
Hydrophilic polymer surface modification of stainless steel stents decreases initial stent surface platelet accumulation, which may decrease the risk of vessel thrombosis associated with the use of these devices.
不锈钢血管内支架本质上具有血栓形成倾向，因此血栓会在这些装置上积聚，导致急性血管闭塞。解决这一问题的一个潜在方法是用亲水性聚合物对支架表面进行改性，这可能会限制血小板的黏附和反应性。
将N - 乙烯基吡咯烷酮（NVP）和丙烯酸钾磺丙酯（KSPA）亲水性单体通过γ接枝聚合到1平方厘米的不锈钢平板和4毫米的帕尔马兹不锈钢支架上。然后通过接触角和X射线光电子能谱测量研究改性和普通不锈钢支架的表面特性，并将体外和体内血小板反应性评估为以计数/分钟/平方厘米表示的111铟血小板积聚。
用NVP和KSPA亲水性聚合物对不锈钢平板和支架进行表面改性，显著降低了体外血小板黏附（普通 = 2249 ± 723计数/分钟/平方厘米，NVP = 428 ± 156计数/分钟/平方厘米，KSPA = 958 ± 223计数/分钟/平方厘米）以及血流暴露1小时后的体内血小板积聚（普通 = 1,407 ± 796计数/分钟/平方厘米，NVP = 426 ± 175计数/分钟/平方厘米，KSPA = 399 ± 124计数/分钟/平方厘米）。此外，与普通支架相比，KSPA改性支架上血小板积聚相对于普通支架的指数最低（NVP =普通的79.3% ± 31.7%，KSPA =普通的51.2% ± 36.2%）。表面分析证实了两种单体的表面接枝，扫描电子显微镜记录了接枝后不锈钢支架不规则表面的平滑化。
不锈钢支架的亲水性聚合物表面改性可减少支架表面初期的血小板积聚，这可能会降低与使用这些装置相关的血管血栓形成风险。
