Tajarenejad Hassan, Ansari Mohammad Ali, Akbari Soheila, Yazdanfar Hanieh, Hamidi Seyedeh Mehri
Laser and Plasma Research Institute, Shahid Beheshti University, Tehran 1983969411, Iran.
Biomed Opt Express. 2021 Sep 7;12(10):6013-6023. doi: 10.1364/BOE.438593. eCollection 2021 Oct 1.
The use of nanoparticle photothermal effect as adjuvants in neuromodulation has recently received much attention, with many open questions about new nanostructures' effect on the action potential. The photothermal properties of hexagonal gold nanoparticles are investigated in this work, including the absorption peak wavelength and light-heat conversion rate, using both experimental and simulation methods. Furthermore, the ability to use these nanostructures in axonal neural stimulation and cardiac stimulation by measuring temperature changes of gold nano-hexagons under 532 nm laser irradiation is studied. In addition, their thermal effect on neural responses is investigated by modeling small-diameter unmyelinated axons and heart pacemaker cells. The results show that the increase in temperature caused by these nano-hexagons can successfully stimulate the small diameter axon and produce an action potential. Experiments have also demonstrated that the heat created by gold nano-hexagons affects toad cardiac rhythm and increases T wave amplitude. An increase in T wave amplitude on toad heart rhythm shows the thermal effect of nano hexagons heat on heart pacemaker cells and intracellular ion flows. This work demonstrates the feasibility of utilizing these nanostructures to create portable and compact medical devices, such as optical pacemakers or cardiac stimulation.
纳米颗粒光热效应作为神经调节佐剂的应用近来备受关注，关于新型纳米结构对动作电位的影响存在诸多未决问题。本文采用实验和模拟方法研究了六角形金纳米颗粒的光热性质，包括吸收峰波长和光热转换率。此外，通过测量532nm激光照射下金纳米六边形的温度变化，研究了这些纳米结构在轴突神经刺激和心脏刺激中的应用能力。另外，通过对小直径无髓鞘轴突和心脏起搏器细胞进行建模，研究了它们对神经反应的热效应。结果表明，这些纳米六边形引起的温度升高能够成功刺激小直径轴突并产生动作电位。实验还表明，金纳米六边形产生的热量会影响蟾蜍的心律并增加T波振幅。蟾蜍心律T波振幅的增加表明纳米六边形热量对心脏起搏器细胞和细胞内离子流动的热效应。这项工作证明了利用这些纳米结构制造便携式紧凑型医疗设备（如光学起搏器或心脏刺激器）的可行性。
