O2 microsensors for minimally invasive tissue monitoring
O2 microsensors for minimally invasive tissue monitoring
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DOI：
10.1098/rsif.2004.0013
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发表时间：
2004-11-22
影响因子：
3.9
通讯作者：
Vadgama, P
中科院分区：
文献类型：
--
作者：
Wang, W;Vadgama, P
组织氧合是保证正常组织功能和生存能力的关键因素。连续实时监测组织中的氧分压Po(2)，可以洞察血液循环对组织的氧气供应的动态波动。小型氧传感器能够研究不同位置的组织中Po(2)相对于局部微血管的空间变化。本文讨论了微电极和生物兼容传感器测量Po(2)的方法，并综述了其在人体皮肤中应用的最新进展。重点介绍了现有的几种氧传感器的工作原理及其在体内和组织工程中的潜在应用。给出了当皮肤表面覆盖无氧石蜡油层时，局部缺血再灌流引起的人体皮肤Po(2)的时空变化，推测组织Po(2)的范围在0~60 mm Hg之间。在研究中，Po(2)从皮肤表面的8.0+/-3.2毫米汞柱(n=6)增加到乳头状神经丛上方深度的35.2+/-8.0毫米汞柱(n=9)。组织压缩后Po(2)的时间衰减和压力释放后Po(2)的上升可以用单指数函数来描述。指数衰减的时间常数tau=8.44+/-1.53 S(n=7)大于指数上升的时间常数tau‘=4.75+/-0.82 S(n=6)。在组织压迫和压力释放后，Po(2)随时间变化的差异揭示了这两个瞬变阶段所涉及的不同的动力学机制。再灌注后稳态Po(2)升高，较阻断前升高约20%，提示局部反应性充血。还讨论了O-2微型传感器在肿瘤、压疮等疾病中的可能应用。
Tissue oxygenation is a key factor ensuring normal tissue functions and viability. Continuous real-time monitoring of the partial pressure of oxygen, pO(2), in tissues gives insight into the dynamic fluctuations of O-2 supplies to tissues by blood circulation. Small oxygen sensors enable investigations of the spatial variation of pO(2) in tissues at different locations in relation to local microvessels. In this paper, pO(2) measurement using microelectrodes and biocompatible sensors is discussed and recent progress of their application in human skin is reviewed. Emphasis is given to working principles of a number of existing oxygen sensors and their potential application in vivo and in tissue engineering. Results on spatial and temporal variations of the pO(2) in human skin introduced by localized ischaemia-reperfusion are presented when the surface of the skin is covered by an oxygen-free paraffin oil layer and the range of the tissue pO(2) is deduced to be between 0 and 60 mmHg. In the study, pO(2) increases from 8.0 +/- 3.2 mmHg (n = 6) at the surface of the skin to 35.2 +/- 8.0 mmHg (n = 9) at a depth just above the subpapillary plexus. Temporal decay in pO(2) following tissue compression and rise in pO(2) following pressure release can be described using mono-exponential functions. The time constant for the exponential decay, tau = 8.44 +/- 1.53 s (n = 7) is consistently greater than that for the exponential rises, tau ' = 4.75 +/- 0.82 s (n = 6). The difference in pO(2) change with the time following tissue compression and pressure release reveals different dynamic mechanisms involved in the two transient phases. The elevated steady state pO(2) following reperfusion, which is approximately 20% higher than the pre-occlusion value, indicates localized reactive hyperaemia. Possible applications of O-2 microsensors in diseases, e.g. tumours, pressure ulcers, are also discussed.