生物医用微纳米马达用于血管类疾病诊疗及伤口抗菌治疗

【作者】 方丹；

【导师】 毛春； 万密密；

【作者基本信息】 南京师范大学 ， 高分子化学与物理， 2022， 硕士

【摘要】 凭借着将不同形式能量转化为机械运动的特性及其微纳米尺度效应,微纳米马达为突破传统纳米材料在重大疾病诊疗中的局限性带来了可能。本论文将生物医用微纳米马达技术应用于血管类疾病及伤口抗菌诊疗研究。主要研究内容如下:1.检测血液中氧化低密度脂蛋白（Ox-LDL）浓度对动脉粥样硬化（AS）的早期预防和干预具有重要意义。传统的临床检测需要经历分离、纯化等复杂而耗时的操作。基于此,本论文构建了一种血液相容性良好的镁基微马达电化学传感器,可对全血中的Ox-LDL进行直接检测,不需要经历复杂的血液样本处理过程。首先,利用Mg基微马达的运动能力实现对血液中Ox-LDL的主动捕获。随后,通过磁力作用以及自制漏斗装置,将捕获到的Ox-LDL富集在经多壁碳纳米管（MWNTs）修饰的磁性玻碳电极（MGCE）上,最后进行电化学检测。该镁基微马达电化学传感器能以简便、快速、高效的方式实现对全血中Ox-LDL的捕获、富集、回收和检测,检测限低至9.80×10^-4μg/m L。2.血栓的形成是许多致死性血管类疾病的根源,而传统的给药方式会由于血液的快速流动而导致药物在栓块部位滞留率低、溶栓效果欠佳。基于此,本论文构建了一种可在近红外光（NIR）和一氧化氮（NO）双驱动下产生自主运动能力的纳米马达,用于提高溶栓效率的研究。首先,制备具有不对称结构的碗状介孔聚多巴胺纳米粒子,在其表面修饰血栓靶向物质精氨酸-甘氨酸-天冬氨酸肽链（RGD）,并在其孔道中装载溶栓药物尿激酶（UK）。RGD能够使纳米马达靶向血栓部位,同时RGD中的L-精氨酸片段所含有胍基能与血栓微环境中的活性氧（ROS）相互作用产生NO。NO不仅能为纳米马达的自主运动提供动力,还能促进内皮细胞的生长,修复受损血管。聚多巴胺具有良好的光热转换效果,在NIR照射下既可以通过光热效果消融血栓,还可以为马达提供推动力。体内实验结果证实,纳米马达在双驱动作用下能够实现对血栓的高效渗透,并从孔道中释放出UK,最后通过光热和药物协同作用溶解血栓。3.细菌群落形成的生物膜屏障能够阻止杀菌物质与生物膜内的细菌相互作用,由此大大减弱抗菌治疗效果。基于此,本论文设计了一种伤口抗菌治疗用的微针贴片,将细菌群体免疫抑制剂木犀草素（Le）以及具有多重抗菌性能的纳米马达装载至微针中。微针可以有效穿透生物膜屏障,并在生物膜内快速溶解释放药物Le和纳米马达。Le可以切断细菌之间的交流,抑制生物膜进一步生长。在NIR的照射下,纳米马达会产生光热效果、单线态氧（¹O₂）和NO多重杀菌作用。在NIR和NO的双重驱动作用下,纳米马达能够在生物膜中进行自主运动,从而扩大多种抗菌方式在生物膜内的作用范围,提高杀菌效果,加速伤口的愈合效率。更多还原

【Abstract】 With the characteristics of converting different forms of energy into mechanical motion and their micro/nanoscale effects,micro/nanomotors have brought the possibility to break through the limitations of traditional nanoparticles in the diagnosis and treatment of serious diseases.In this thesis,the biomedical micro/nanomotor technology was applied to the research of the diagnosis and treatment of vascular diseases and antibacterial treatment of wounds.The main research contents are as follows:1.Detection of oxidized low-density lipoprotein（Ox-LDL）concentration is of great significance for the early prevention and intervention of atherosclerosis（AS）.Traditional clinical detection requires complex and time-consuming operations,such as separation and purification.Based on this,we constructed a magnesium-based micromotor electrochemical sensor platform,which can directly detect Ox-LDL in whole blood without complicated blood sample processing.Firstly,the active capture of Ox-LDL in blood can be realized by utilizing the motion capability of the micromotors.Subsequently,by magnetic interaction and a self-made funnel device,the captured Ox-LDL was enriched on magnetic glassy carbon electrode（MGCE）which modified with the multi-walled carbon nanotubes（MWNTs）.Finally,the electrochemical detection was performed.The magnesium-based micromotor electrochemical sensor can realize the capture,enrichment,recovery and detection of Ox-LDL in whole blood in a simple,fast and efficient way,the detection limit of this sensor was as low as 9.80×10^-4μg/m L.2.The formation of thrombus is the root cause of many fatal vascular diseases,and the traditional drug delivery method will lead to the low retention rate of drugs at the thrombus site and poor thrombolytic effect due to the rapid blood flow.Based on this background,we constructed a nanomotor that can generate autonomous movement under the dual drive force of near-infrared light（NIR）and nitric oxide（NO）for the research of improving thrombolysis efficiency.Firstly,bowl-like mesoporous polydopamine nanoparticles with asymmetric structure were prepared.The thrombus targeting substance arginine-glycine-aspartic peptide chain（RGD）was modified on its surface,and the thrombolysis drug urokinase（UK）was loaded into the mesoporous of the nanomotors.RGD enables nanomotors to the thrombus site,and the guanidine group in the L-arginine fragment of RGD can interact with reactive oxygen species（ROS）in the thrombus microenvironment to generate NO.NO not only can provide the driving force of movement for nanomotors,but also can promote endothelial cell growth and repair damaged blood vessels.Polydopamine has a good photothermal conversion effect.Under NIR irradiation,it can not only ablate the thrombus through the photothermal effect,but also provide driving force for the nanomotor.The results of in vivo experiments confirmed that the nanomotor can achieve high-efficiency penetration of the thrombus under the action of dual drives,UK was released from the mesopores.Finally,the thrombus was dissolved by the synergistic effect of photothermal and drugs.3.The biofilm barrier formed by the bacterial community can effectively protect the bacteria and prevent bacteria-killing substances entering it,which greatly weakens the therapeutic effect of antibacterial.Based on this,we designed a microneedle patch for antibacterial treatment at wound.The microneedle was loaded with the luteolin（Le）,a bacterial quorum sensing inhibitor,and a nanomotor with multiple antibacterial properties.Microneedles can penetrate the barrier and rapidly release drugs and nanomotors in biofilms.Cutting off the communication between bacteria by Le can inhibit the growth of the biofilm.Under the irradiation of NIR,the nanomotor can produce multiple bactericidal effects,such as photothermal effects,singlet oxygen（¹O₂）and NO.Under the dual driving action of NIR and NO,the autonomous movement of nanomotors can expand the range of various antibacterial methods in biofilms,which can improve the bactericidal effect to accelerate the wound healing efficiency.更多还原