Refined Microdialysis Method for Protein Biomarker Sampling in Acute Brain Injury in the Neurointensive Care Setting
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- 作者：Andreas P. Dahlin ; Karlis Purins ; Fredrik Clausen ; Jiangtao Chu ; Amir Sedigh ; Tomas Lorant ; Per Enblad ; Anders Lew茅n ; Lars Hillered
- 刊名：Analytical Chemistry
- 出版年：2014
- 出版时间：September 2, 2014
- 年：2014
- 卷：86
- 期：17
- 页码：8671-8679
- 全文大小：458K
- ISSN：1520-6882
文摘
There is growing interest in cerebral microdialysis (MD) for sampling of protein biomarkers in neurointensive care (NIC) patients. Published data point to inherent problems with this methodology including protein interaction and biofouling leading to unstable catheter performance. This study tested the in vivo performance of a refined MD method including catheter surface modification, for protein biomarker sampling in a clinically relevant porcine brain injury model. Seven pigs of both sexes (10鈥?2 weeks old; 22.2鈥?7.3 kg) were included. Mean arterial blood pressure, heart rate, intracranial pressure (ICP) and cerebral perfusion pressure was recorded during the stepwise elevation of intracranial pressure by inflation of an epidural balloon catheter with saline (1 mL/20 min) until brain death. One na茂ve MD catheter and one surface modified with Pluronic F-127 (10 mm membrane, 100 kDa molecular weight cutoff MD catheter) were inserted into the right frontal cortex and perfused with mock CSF with 3% Dextran 500 at a flow rate of 1.0 渭L/min and 20 min sample collection. Na茂ve catheters showed unstable fluid recovery, sensitive to ICP changes, which was significantly stabilized by surface modification. Three of seven na茂ve catheters failed to deliver a stable fluid recovery. MD levels of glucose, lactate, pyruvate, glutamate, glycerol and urea measured enzymatically showed an expected gradual ischemic and cellular distress response to the intervention without differences between na茂ve and surface modified catheters. The 17 most common proteins quantified by iTRAQ and nanoflow LC-MS/MS were used as biomarker models. These proteins showed a significantly more homogeneous response to the ICP intervention in surface modified compared to na茂ve MD catheters with improved extraction efficiency for most of the proteins. The refined MD method appears to improve the accuracy and precision of protein biomarker sampling in the NIC setting.