碳量子点对周围神经可塑性和功能储备的在体荧光示踪研究

Early and accurately assessing therapeutic effects of peripheral nerve repair is crucial for predicting functional outcomes, however, current clinical methods can't satisfy this requirment. Therefore, we have been trying to create an in vivo, non-invasive neural tracing method. Carbon quantum dot is a novel fluorescent carbon nanoparticle, which is characterized by small-size, non-toxicity, bioabsorbability and transportability. On the basis of these advantages, we plan to establish a novel in vivo neural tracing method and apply this method to measure the therapeutic effect of peripheral nerve repair, early and accurately. The aim of this project is to study biological activity, cytotoxicity, mechanisms of absorption and intracellular transportation, provide some feasible data about dose, experimental protocol and testing standards. Futhermore, we are going to apply this method to in vivo study mechanisms of neural plasticity, such as power nerves and location, and going to use some intervetions to enhance the plasticity and improve therapeutic effect. At the same time, we will study mechanisms of peripheral nerve functional reserve and compensatory effect by anterograde- and retrograde tracing. In conclusion, we are going to synthesize a novel, inexpensive, nontoxic neural tracer and establish an in vivo method measuring peripheral nerve regeneration. This project will be significant of improving the entire therapeutic effects of peripheral nerve injury and of creating new operating methods.

早期准确判断周围神经损伤后修复效果对于预测神经功能转归具有重要意义，而目前临床检测尚无法达到要求。由此，本课题组一直致力于研发在体无创神经示踪技术。最新合成的碳量子点具有直径小、无毒性、可吸收及可转运等特点，适用于活体观测，可望利用这些特性建立一种新型神经示踪技术，用于在体无创直观评价周围神经损伤后修复疗效。本课题将研究碳量子点的生物学活性、细胞毒性及细胞内吸收转运机制，为使用剂量、操作方法及检测标准提供可行性数据，建立新型在体神经示踪技术。应用此新技术在体研究神经可塑性的转化机制、部位、动力神经的来源，以期通过干预手段增强可塑性的转化能力从而提高周围神经损伤后治疗效果；并通过顺行、逆行示踪技术，探讨周围神经功能储备及代偿作用的机制。通过本课题的研究，可望为周围神经损伤提供一种新型、价廉、无创、无毒、可直接观测的示踪材料和技术，对提高周围神经损伤的总体疗效，开创新的手术方法具有重要意义。

周围神经损伤是临床上的常见病、多发病，也是疑难病，其难点是损伤后神经功能恢复欠佳甚至不恢复。临床上判断神经功能恢复及轴突再生水平方法缺乏时效性且判断结果受主观因素影响不够准确也不直观。利用基于具有独特荧光特性的无毒性碳点的新型神经示踪技术，既可有效克服传统示踪技术复杂的操作过程、费时的免疫组化染色、荧光信号弱以及易光漂白等缺点，又可通过改变纳米粒子理化性质进而控制其荧光性质，实现活体无创直观检测周围神经损伤再生水平。本课题围绕碳纳米点、聚合物碳点、石墨烯量子点以及最新合成的多功能近红外碳点开展一系列细胞行为学、周围神经示踪以及周围神经损伤再生水平检测等研究，一方面在原有碳基荧光纳米粒子基础上，阐明其复杂细胞摄取机制与细胞内分布，并创制出基于碳纳米点的无毒性荧光神经示踪剂，并成功应用于周围神经逆行示踪以及周围神经损伤再生研究，为新一代荧光纳米粒子相关神经示踪剂的研发奠定实验基础，拓展新思路；另一方面，延续新型荧光纳米神经示踪剂涉及思路，创制出最新多功能近红外碳点，并开展相关细胞动物实验，为进一步实现活体无创神经再生水平检测奠定实验基础。本课题发表相关SCI文章11篇，最高影响因子7.8，为当期封面文章，并以此为基础成功获得2017年国家自然科学基金面上项目1项，为周围神经损伤总体疗效提供新的评价方法，有效提高周围神经损伤预后效果，解决临床治疗困难。