柔性纳米压电设备延展性和弯曲性的体内测试

Stretchability and Flexibility of an Ultra-flexible Piezoelectric Device: in vivo Testing

目的在生物体内柔性环境下测试微型纳米压电设备的延展性和弯曲性,为进一步研究提供动物实验数据。方法实验组和对照组家兔各20只,将微型柔性纳米压电器件缝合在实验组家兔心脏表面;对照组只进行开胸,不在心脏表面缝合器件。分别比较关胸前,术后1天和第1、2、3、4周时实验组和对照组家兔的体重、心率、呼吸、血压等生理指标,术后4周时心肌组织标本,以及实验前后柔性纳米压电芯片的物理性能。结果实验组家兔实验前后生理指标分别与对照组比较,差异均无统计学意义(P>0.05);对不同时刻重复测量的家兔体重、心率、呼吸和收缩压进行混合模型分析发现,在实验组和对照组两组间相比,P值分别为0.54、0.47、0.86、0.46,差异均无统计学意义;术后4周实验组与对照组家兔心肌组织切片的HE、Masson、CD 68和TUNEL染色均未发现病理性损伤,两组间相比差异无统计学意义;纳米压电芯片在实验组实验前后的能量收集性能差异无统计学意义(P>0.05);4周时,以光学和扫描电子显微镜(scanning electron microscope,SEM)观察芯片,均未发现表面断裂(P=1.00)。结论柔性纳米压电芯片在短期动物体内测试中运行良好,对家兔的基本生命指标无影响、对心肌组织无损伤,表明此纳米压电芯片具有较好的延展性和弯曲性,达到了在生物柔性组织环境内正常工作、无组织损害的基本要求。

Objective To validate the stretchability and flexibility of an ultra - flexible piezoelectric device with in vivo testing and to provide experimental data for further researches. Methods Each group of the experimental and control groups contains 20 experimental rabbits. In animals of the experimental group, ultra - flexible piezoelectric devices were sutured on the surface of the heart. In animals of the control group, only thoracotomy was performed, without suturing ultra - flexible devices. Parameters and vital signs including the body weight, heart rate, respiratory rate, systolic blood pressure and the physical properties of the ultra -flexible devices were recorded before and after sternal closure, at 1 day, 1 week, 2, 3 and 4 weeks postoperatively and histological stains were compared between the 2 groups at 4 weeks. Results Before and after the operation, there were no significant differences in the parameters and vital signs between the experimental and control groups （P 〉 0.05 ）. Linear mixed model estimates revealed that there were no statistical differences in the weight （P = 0. 54） , heart rate （ P = 0. 47） , systolic blood pressure （P = 0. 86 ） and respiratory rate （ P = 0. 46 ） between the experimental and control groups. Histological stains detected no lesions of the myocardium in both groups with hematoxylin and eosin （HE stain） , Masson, TUNEL and CD 68 stainings. In the experimental group, the ultra - flexible piezoelectric devices were functioning well before and after the operation （P 〉 0.05）. At 4 weeks, optical microscopy and scanning electron microscopy （SEM） showed that the microstructure of all explanted devices was intact （P = 1.00）. Conclusion The results of in vivo testing confirmed the stretchability, flexibility and energy harvesting performance of the ultra - flexible piezoelectric devices. It did not cause damages to the respiratory and cardiovascular functions and to the myoeardium, which proved its biocompatibility. This study implies that implantable ultra - flexible piezoelectric devices may represent a new strategy of power supply for implantable electric devices.