Development of Dynamic Sensing System to Detect Environmental Stresses Induced in Living Cell. - Application to Diagnosis of Living Cell

本文提出了一种利用压电振子的动态响应来检测细胞状微小物体内部环境应力的新方法。实验研究表明，它能够检测环境应力诱导的鱼卵细胞的变化以及组织工程化三维培养软骨的硬化过程。结果可归纳如下。(1)提出了一种利用压电振子动态响应检测海绵状、细胞状微小物体柔软度的新方法。在硅橡胶块上进行的实验研究表明，该传感器能够对海绵状软物体的柔软度进行分类，硅橡胶块的海岸硬度Hs已知为5-80。(2)借助于该传感系统，发现了活的鳉鱼卵细胞对环境的特定反应，例如周围溶液的温度、浓度、pH、环境激素等的变化或施加到细胞外表面的抽吸压力。因此，本传感器系统具有足够的能力来监测在活细胞中诱导的环境应力。(3)研究了组织工程化三维（3D）培养软骨的硬化过程与培养时间的关系。动力学特性以及生化成分进行了检查。本研究为判断培养软骨是否具有足够的硬度用于关节软骨损伤的移植治疗提供了依据。

In this study, a novel method to detect the environmental stresses induced in cell-like minute object is presented by using dynamic response of piezoelectric vibrator. Experimental studies have shown its capability to detect changes of the environmental stresses induced in egg cells of killifish as well as hardening process of tissue-engineered 3D cultured cartilage. The results can be summarized as follows.(1) A novel method of sensing to detect the softness of sponge-like soft and cell-like minute object is specifically presented by using dynamic response of piezoelectric vibrator. Experimental studies conducted on silicone rubber blocks, whose Shore hardness, Hs are known as 5-80, have shown the sensor's capability to classify the softness of sponge-like soft object.(2) With the aid of this sensing system, it is found that the living egg cells of killifish reveal their specific responses to the environments such as changes of temperature, concentration, pH, environmental hormone, etc. of surrounding solution or sucking pressure applied to the outside surface of the cell. Thus, the present sensor system has enough capability to monitor the environmental stresses induced in living cells.(3) The hardening process of tissue-engineered three dimensionally (3D) cultured cartilage has been studied with respect to culture periods. Dynamic properties as well as biochemical composition were examined. It is found that the present study has a possibility to provide a useful information to decide whether the cultured cartilage has enough hardness for transplantation treatment of articular cartilage damage.