Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC, USA.
Biophys J. 2010 Oct 6;99(7):2374-83. doi: 10.1016/j.bpj.2010.08.007.
This article introduces a new functional imaging paradigm that uses optical coherence tomography (OCT) to detect rehydrated, lyophilized platelets (RL platelets) that are in the preclinical trial stage and contain superparamagnetic iron oxides (SPIOs) approved by the U.S. Food and Drug Administration. Platelets are highly functional blood cells that detect and adhere to sites of vascular endothelial damage by forming primary hemostatic plugs. By applying magnetic gradient forces, induced nanoscale displacements (magnetomotion) of the SPIO-RL platelets are detected as optical phase shifts in OCT. In this article, we characterize the iron content and magnetic properties of SPIO-RL platelets, construct a model to predict their magnetomotion in a tissue medium, and demonstrate OCT imaging in tissue phantoms and ex vivo pig arteries. Tissue phantoms containing SPIO-RL platelets exhibited >3 dB contrast/noise ratio at ≥1.5 × 10(9) platelets/cm(3). OCT imaging was performed on ex vivo porcine arteries after infusion of SPIO-RL platelets, and specific contrast was obtained on an artery that was surface-damaged (P < 10(-6)). This may enable new technologies for in vivo monitoring of the adherence of SPIO-RL platelets to sites of bleeding and vascular damage, which is broadly applicable for assessing trauma and cardiovascular diseases.
本文介绍了一种新的功能成像范例，该范例使用光学相干断层扫描（OCT）来检测处于临床前试验阶段且含有经美国食品和药物管理局批准的超顺磁氧化铁（SPIOs）的再水合、冻干血小板（RL 血小板）。血小板是具有高度功能的血细胞，通过形成初级止血塞来检测和黏附到血管内皮损伤部位。通过施加磁场梯度力，SPIOs-RL 血小板的纳米级位移（磁运动）会在 OCT 中被检测为光学相位移动。在本文中，我们对 SPIOs-RL 血小板的铁含量和磁性能进行了表征，构建了一个可预测其在组织介质中磁运动的模型，并在组织体模和离体猪动脉中进行了 OCT 成像演示。在含有 SPIOs-RL 血小板的组织体模中，在≥1.5×10(9)个血小板/cm(3)时，对比度/噪声比大于 3 dB。在输注 SPIOs-RL 血小板后，对离体猪动脉进行了 OCT 成像，在表面受损的动脉上获得了特异性对比（P < 10(-6)）。这可能为体内监测 SPIOs-RL 血小板黏附到出血和血管损伤部位的新技术提供了可能，该技术广泛适用于评估创伤和心血管疾病。
