Microfiltration platform for continuous blood plasma protein extraction from whole blood during cardiac surgery.
Microfiltration platform for continuous blood plasma protein extraction from whole blood during cardiac surgery.
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DOI：
10.1039/c1lc20080a
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发表时间：
2011-09-07
期刊：
影响因子：
6.1
通讯作者：
Zahn JD
中科院分区：
文献类型：
--
作者：
Aran K;Fok A;Sasso LA;Kamdar N;Guan Y;Sun Q;Ündar A;Zahn JD
本报告描述了交叉流过滤微型装置的设计、制造和测试，用于在临床相关环境中从循环全血样品中连续提取血浆，以帮助在涉及心肺旁路（CPB）程序的心脏手术期间连续监测患者的炎症反应（美国每年约有40万成人和2万儿科患者）。微滤系统由具有两组对齐的PDMS微通道的双室质量交换器组成，由多孔聚碳酸酯（PCTE）膜隔开。使用这种微型装置，血浆已被连续地从血细胞中实时分离，没有生物污染或细胞裂解的证据。该技术旨在使用与传统血液采集技术相比显著更小的血液体积连续提取含有诊断血浆蛋白（如补体和细胞因子）的血浆。采用与临床手术设置相同的方式，使用灌注供体人血的模拟CPB循环回路对微滤装置进行了测试，以收集血浆组分，从而研究CPB系统组件和循环对体外循环支持期间免疫激活的影响。将膜孔径为200 nm的微型装置连接到模拟CPB回路，能够以高采样频率连续提取约15%纯血浆体积（100%无细胞），采集后可直接进行分析，无需进一步离心或修改馏分。在4小时的采样期内采集不到2.5 ml总血浆体积（不到一个采血管采血管体积）。结果跟踪了从储液器和滤液样品中收集的细胞因子浓度，其与直接抽血的细胞因子浓度相当，表明微型器械的蛋白质回收率非常高。此外，对于所分析的所有细胞因子，在循环时间内，细胞因子浓度与基线值相比显著增加。在实验期间（超过4小时），高血浆蛋白回收率（超过80%）、无溶血迹象和膜表面生物污染水平低，均表明器械性能有效且可靠，可用于未来临床应用。这些器械的设计和操作简单而稳健，允许在广泛的实验流动条件和血液红细胞压积水平下操作，从而允许外科医生和临床医生在临床环境中自主使用，以更好地了解心脏手术导致的损伤机制，并允许对术后并发症过多的患者进行早期干预，以改善手术结局。最终，这种微滤装置与连续微量免疫测定的整体集成将创建用于跟踪患者中的炎症生物标志物浓度的集成微量分析系统，用于即时诊断，减少血液分析时间，成本和重复测定所需的血液样品的体积。
This report describes the design, fabrication, and testing of a cross-flow filtration microdevice, for the continuous extraction of blood plasma from a circulating whole blood sample in a clinically relevant environment to assist in continuous monitoring of a patient’s inflammatory response during cardiac surgeries involving cardiopulmonary bypass (CPB) procedures (about 400 000 adult and 20 000 pediatric patients in the United States per year). The microfiltration system consists of a two-compartment mass exchanger with two aligned sets of PDMS microchannels, separated by a porous polycarbonate (PCTE) membrane. Using this microdevice, blood plasma has been continuously separated from blood cells in a real-time manner with no evidence of bio-fouling or cell lysis. The technology is designed to continuously extract plasma containing diagnostic plasma proteins such as complements and cytokines using a significantly smaller blood volume as compared to traditional blood collection techniques. The microfiltration device has been tested using a simulated CPB circulation loop primed with donor human blood, in a manner identical to a clinical surgical setup, to collect plasma fractions in order to study the effects of CPB system components and circulation on immune activation during extracorporeal circulatory support. The microdevice, with 200 nm membrane pore size, was connected to a simulated CPB circuit, and was able to continuously extract ~15% pure plasma volume (100% cell-free) with high sampling frequencies which could be analyzed directly following collection with no need to further centrifuge or modify the fraction. Less than 2.5 ml total plasma volume was collected over a 4 h sampling period (less than one Vacutainer blood collection tube volume). The results tracked cytokine concentrations collected from both the reservoir and filtrate samples which were comparable to those from direct blood draws, indicating very high protein recovery of the microdevice. Additionally, the cytokine concentration increased significantly compared to baseline values over the circulation time for all cytokines analyzed. The high plasma protein recovery (over 80%), no indication of hemolysis and low level of biofouling on the membrane surface during the experimental period (over 4 h) were all indications of effective and reliable device performance for future clinical applications. The simple and robust design and operation of these devices allow operation over a wide range of experimental flow conditions and blood hematocrit levels to allow surgeons and clinicians autonomous usage in a clinical environment to better understand the mechanisms of injury resulting from cardiac surgery, and allow early interventions in patients with excessive postoperative complications to improve surgical outcomes. Ultimately, monolithic integration of this microfiltration device with a continuous microimmunoassay would create an integrated microanalysis system for tracking inflammation biomarkers concentrations in patients for point-of-care diagnostics, reducing blood analysis times, costs and volume of blood samples required for repeated assays.