Longitudinal in vivo imaging to assess blood flow and oxygenation in implantable engineered tissues.
Longitudinal in vivo imaging to assess blood flow and oxygenation in implantable engineered tissues.
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DOI：
10.1089/ten.tec.2011.0744
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发表时间：
2012-05
期刊：
影响因子：
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通讯作者：
Sean M. White;R. Hingorani;Rajan P S Arora;C. Hughes;S. George;Bernard Choi
中科院分区：
文献类型：
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作者：
Sean M. White;R. Hingorani;Rajan P S Arora;C. Hughes;S. George;Bernard Choi
植入的无血管组织内的血管网络的功能很难用传统的分析技术，如组织学来评估。这在很大程度上是由于无法纵向显示体内的血流动力学。因此，我们开发了动态成像方法，以无创和纵向地测量植入的前血管组织中的血流量和血红蛋白氧饱和度。利用激光散斑成像、多光谱成像和活体显微镜，我们证明了基于纤维蛋白的组织植入物在短短20小时内与宿主(严重联合免疫缺陷小鼠)吻合。吻合导致初始血液灌流，血液含氧量高，平均血红蛋白含氧量增加53%。然而，预制血管的切变率较低(2 0.8±12.8 S(-1))，绝大多数预制血管因血栓形成而不能持续流动。这些发现表明，在血管形成前的组织中设计适当的血管网络结构，以保持血栓形成阈值以上的切变率，可能是维持植入后血流的必要手段。我们的结论是，宽视野和显微功能成像可以动态评估体内血管前病变组织的血流和氧合情况，并可用于快速评估和改进血管前病变策略。
The functionality of vascular networks within implanted prevascularized tissues is difficult to assess using traditional analysis techniques, such as histology. This is largely due to the inability to visualize hemodynamics in vivo longitudinally. Therefore, we have developed dynamic imaging methods to measure blood flow and hemoglobin oxygen saturation in implanted prevascularized tissues noninvasively and longitudinally. Using laser speckle imaging, multispectral imaging, and intravital microscopy, we demonstrate that fibrin-based tissue implants anastomose with the host (severe combined immunodeficient mice) in as short as 20 h. Anastomosis results in initial perfusion with highly oxygenated blood, and an increase in average hemoglobin oxygenation of 53%. However, shear rates in the preformed vessels were low (20.8±12.8 s(-1)), and flow did not persist in the vast majority of preformed vessels due to thrombus formation. These findings suggest that designing an appropriate vascular network structure in prevascularized tissues to maintain shear rates above the threshold for thrombosis may be necessary to maintain flow following implantation. We conclude that wide-field and microscopic functional imaging can dynamically assess blood flow and oxygenation in vivo in prevascularized tissues, and can be used to rapidly evaluate and improve prevascularization strategies.