复合甘草酸碳点对猪繁殖与呼吸综合征病毒的抑制作用及机制

Carbon dots are a kind of carbon nanoparticles in the range of 1-10 nm, which not only have excellent luminescent properties and good biocompatibility, but also induce the production of interferon, so they are good materials for the preparation of highly effective antiviral drugs. In this project, glycyrrhizic acid, which can inhibit proliferation of porcine reproductive and respiratory syndrome virus (PRRSV), is used as precursor to prepare glycyrrhizic acid-carbon dots by the hydrothermal carbonization technology. To improve the antiviral specificity of carbon dots, PRRSV specific aptamers are attached to the surface of the glycyrrhizic acid-carbon dots by covalent coupling method. To enhance the ability of carbon dots to enter cells, calcium phosphate is further coated in the surface of glycyrrhizic acid-carbon dots by using biomimetic technology. Based on above processes, composite glycyrrhizic acid-carbon dots (composite carbon dots) with high efficiency and specificity of inhibition for PRRSV are obtained. The inhibition effects of composite carbon dots, glycyrrhizic acid-carbon dots and glycyrrhizic acid on PRRSV are compared on the cellular level. The inhibition mechanism of composite carbon dots on PRRSV is revealed according to the influence of virus replication cycle and the ability of inducing interferon. On this basis, the effect of composite carbon dots on the prevention and treatment of porcine reproductive and respiratory syndrome (PRRS) is evaluated by using PRRSV artificial infection weaned piglets as models. The study not only provides a novel idea for the prevention and control of PRRS, but also is used for reference in antiviral investigation of other Chinese herbal medicines.

碳点是一种尺寸介于1-10 nm的碳纳米粒子，不仅具有良好的发光特性和生物相容性，而且其本身还能诱导干扰素产生，是制备高效抗病毒药物的良好材料。本项目拟采用对猪繁殖与呼吸综合征病毒(PRRSV)有抑制效果的甘草酸为原料，通过水热炭化技术制备甘草酸碳点，采用共价偶联方法将PRRSV特异性核酸适配体偶联到碳点表面，提高碳点抗病毒特异性；利用仿生矿化技术将磷酸钙进一步修饰在碳点表面，增强其进入细胞的能力，从而获得对PRRSV具有高效、特异性抑制作用的复合甘草酸碳点(简称复合碳点)。在细胞水平上比较复合碳点、甘草酸碳点及甘草酸对PRRSV的抑制效果，并从对病毒复制周期的影响以及诱导干扰素能力等方面揭示复合碳点抑制PRRSV的机制；在此基础上，以断奶仔猪为模型，评价复合碳点对猪繁殖与呼吸综合征(PRRS)的预防和治疗效果。本研究不仅为PRRS的防控提供新的思路，还可为其他中草药抗病毒研究提供借鉴。

碳点是一种尺寸介于1-10 nm的碳纳米粒子，不仅具有良好的发光特性和生物相容性，而且其本身还能诱导干扰素产生，是制备高效抗病毒药物良好材料。前期研究证实甘草酸对猪繁殖与呼吸系统综合征病毒（PRRSV）具有一定的抑制效果。本项目以甘草酸、柠檬酸、谷胱甘肽等为原料，合成了甘草酸碳点、甘草酸修饰金纳米粒子、谷胱甘肽修饰硫化锌纳米粒子、硫点等纳米材料，研究了碳点及硫点的光稳定性，在细胞水平上比较了不同材料对PRRSV的抑制效果，并从对病毒复制周期的影响以及诱导干扰素能力等方面揭示复合碳点、硫化锌纳米粒子等材料抑制PRRSV的机制；发现甘草酸碳点不仅可以刺激细胞产生先天免疫反应，抑制胞内活性氧积累，还可调控细胞中宿主限制性因子的表达，从多方面抑制病毒的增殖。在此基础上，以断奶仔猪为模型，评价了碳点对PRRSV的治疗效果。本研究不仅为PRRSV的防控提供新的思路，还可为其他中草药抗病毒研究提供借鉴。. 在课题执行过程中，撰写《纳米荧光探针》（第二版）学术著作1部，发表论文10篇，其中SCI收录论文5篇（高被引论文2篇），EI收录论文1篇，另有1篇论文正在审稿中，1篇论文正整理之中。参加国内学术会议11人次，在会上做学术报告5次，培养博士研究生1名，硕士研究生5名。