Institut de Microelectrònica de Barcelona IMB-CNM (CSIC), Bellaterra 08193, Barcelona, Spain.
Biosens Bioelectron. 2012 Jan 15;31(1):55-61. doi: 10.1016/j.bios.2011.09.039. Epub 2011 Oct 5.
The permeability of the cornea epithelial layer has an important role in optimal function of the cornea. To assess this property quantitatively, methods must be based on the passive electrical properties of living tissues, as they can take advantage of the fundamental role that ionic permeability plays in such properties. For such techniques, measurement of the translayer electrical resistance (TER) has been consistently used to examine the ion transport mechanisms in the corneal epithelial cells; however, this technique has been only possible in vitro. To enhance the applications of this method, in this work we present a novel sensor to perform non-invasive in vivo TER measurements. Herein, the epithelial permeability was assessed using non-invasive tetrapolar impedance measurements that were performed with four electrodes placed on the corneal surface. The geometry of these electrodes was previously optimized to maximize the sensitivity of the corneal epithelium. To evaluate the feasibility of this sensor, the permeability of a rabbit corneal epithelium was monitored by applying a solution of benzalkonium chloride (0.05% BAC). The results validate the capability of the sensor to evaluate the cornea epithelial permeability in vivo.
角膜上皮层的通透性对角膜的最佳功能具有重要作用。为了定量评估此性质，方法必须基于活体组织的被动电学特性，因为它们可以利用离子通透性在这些特性中所起的基本作用。对于此类技术，跨层电阻 (TER) 的测量一直被用于检查角膜上皮细胞中的离子转运机制；但是，这种技术仅在体外才有可能。为了增强该方法的应用，在这项工作中，我们提出了一种新的传感器来进行非侵入性的体内 TER 测量。在此，使用放置在角膜表面上的四个电极进行非侵入性四极阻抗测量来评估上皮通透性。这些电极的几何形状先前已进行了优化，以最大程度地提高角膜上皮的灵敏度。为了评估该传感器的可行性，通过施加 0.05%苯扎氯铵（BAC）溶液来监测兔角膜上皮的通透性。结果验证了该传感器在体内评估角膜上皮通透性的能力。
