随着我国纳米科技的发展与进步，纳米材料逐渐在新能源、电子电器、化学化工、生物医学等领域崭露头角。特别是其可控的尺寸和形貌与多功能特性，为日益增长的生物医学领域的需求提供了不可或缺的力量。目前，诸如二维层状纳米材料(硫化钼、硫化钨、石墨烯等)、碳基量子点纳米材料(碳量子点、富勒烯、石墨烯量子点等)、金属化合物纳米材料(硒化镉、氧化铁、硒化锌等)、有机高分子纳米材料(嵌段共聚物、树枝状聚合物等)以及贵金属纳米材料(金、银、铂)等多种纳米材料，基于其独特的结构特点、光学特行以及便捷、可控的制备手段，已经在生物医学诊疗领域得到了广泛关注，尤其是在疾病治疗和检测研究方面具有十分巨大的价值。但是，以纳米材料为基础构建的具有多功能特性的纳米诊疗体系，依然存在着诸多问题。首先，纳米材料作为治疗药剂时，其通过包括血液输送、口服、腹腔注射、吸入等诸多方式到达病灶，而上述过程均会涉及到纳米材料与正常组织器官的接触以及和免疫系统的相互作用。而传统纳米材料的化学稳定性以及尺寸导致的滞留作用均会带来不可预见的毒副作用。其次，在疾病诊断领域，离体血液检测体系通常借助仪器和探针来完成，特别是在血糖相关疾病的诊断中均涉及到天然酶的使用。这就要求所使用的酶具有制备简单、使用条件宽泛的基本要求。但是，天然酶容易失活的特点和苛刻的使用条件，始终制约着其进一步的普及。基于上述问题，本论文以贵金属纳米材料为基础，利用其稳定的化学特性、便捷的合成手段、具有多功能化的特点，通过合成、修饰等手段，构建了两种有望解决上述两种问题的金纳米诊疗药剂和能够替代天然酶的铂纳米酶。通过调控配体修饰方式赋予金纳米颗粒具备体内输送快、病灶富集率高、治疗后滞留短的智能纳米药物。通过便捷的合成方法，得到了铂纳米颗粒，其具有优良的类天然酶催化活性，能够替代辣根过氧化物酶快速构建过氧化氢和葡萄糖的离体检测体系。具体研究内容如下：

(1) 设计合成两种烷基链长度的pH响应特性的配体，以金纳米颗粒为基础，构建两种不同长度烷基链的pH响应聚集特性的金纳米药物。利用紫外可见光谱、透射电子显微镜、动态光散射等手段，研究了配体配比对pH响应聚集特性的影响规律。以此为基础，详细探讨了配体长度对金纳米颗粒近红外光热特性的影响规律。进一步研究了不同配体修饰对金纳米药物pH响应聚集后解体的行为差异，并对其内在机制进行了初步分析，此外，初步验证了其在活体应用的可能性。

(2) 通过便捷的合成手段，以铂纳米颗粒为构建基础，构建具有过氧化物酶催化活性的贵金属基纳米酶。利用稳态动力学分析手段对比了其与辣根过氧化物酶的催化活性差异，提出其具有底物依赖的催化活性。其拟酶催化活性较天然酶有显著提高，且催化速度快，灵敏度高，可进一步应用于过氧化氢检测。以此为基础，我们构建了血清葡萄糖检测体系，与传统血糖仪对比可见其检出限和线性范围较为符合实际使用，且相对天然酶具有更稳定的检测性能。

Versatile nanomaterials have been utilized in the fields of new energy, electronic appliances, chemical industry and biomedical science, due to the development of domestic nanotechnology. Particularly, the multi-functionalization property of nanomaterials has promoted them to play a key role in the future of biomedical fields. The characteristics of nanomaterials, such as unique structure and optic property, and convenient and controllable synthesis procedure, have been gained much attention in diagnose and disease quantification. However, some issues still hampered the nanomedicine derived from multi-functionalized nanomaterials for biomedical application. Firstly, for disease therapy, the nanomedicine was administrated by varies routes including oral, nasal, pulmonary, transdermal and parenteral. During the drug delivery, the inevitable interaction between nanotherapeutics and normal tissue and organs may cause unpredictable side-effects and even induce toxicity. Secondly, for disease diagnose, the fluctuated level of blood glucose represented the malfunction of organs such as pancreas and cancer. Nevertheless, the quantification of glucose in vitro is always depended on the naturally-obtained peroxidase which processed a weak tolerance for the environmental change. Therefore, the fragile nature of enzyme is a critical issue for constructing a glucose detection system.

 

In this thesis, we have developed two different nanomedicines derived from noble metals for therapy and detection respectively. The convenient synthesis procedure, easy modification, and stable characteristic of gold and platinum nanomaterials fulfilled the needs of the nanomedicine for biomedical purpose. By regulating the ligand modification method, gold nanoparticles were endowed with fast delivery and responsive aggregation under particular pH condition, and followed by a short retention after therapy, which may remove the bottleneck of nanomedicine including side-effect. Through a convenient synthesis method, platinum nanoparticles were obtained, which have excellent natural peroxidase-like catalytic activity and could replace horseradish peroxidase to rapidly construct an in vitro detection system for hydrogen peroxide and glucose. Specifically, our research includes:

 

(1) Design and synthesize two kinds of pH-responsive ligands with different alkyl chain length. The gold nanomedicines with two kinds of ligands exhibited different pH-responsive aggregation behavior. By using UV-visible spectroscopy, transmission electron microscopy, dynamic light scattering and other methods, the effect of ligand ratio on the aggregation characteristics of pH response of gold nanomedicine was studied. The influence of the length of the ligand on the near-infrared photothermal properties of gold nanoparticles was discussed in detail. The different disassembly behaviors between two kinds of ligands of gold nanomedicine were further discussed, and its internal mechanism was preliminary analyzed. In addition, the possibility of gold nanomedicine application in vivo was preliminarily verified.

 

(2) Platinum nanoparticles-based nanozyme with peroxidase catalytic activity through convenient synthetic methods was constructed. The steady-state kinetic analysis method was used to compare the catalytic activity of horseradish peroxidase and Pt nanozyme, and it was found that a substrate-dependent catalytic activity governed the enzyme-like activity. Compared with natural enzymes, the catalytic activity of the platinum nanoparticles was significantly improved, as well as the catalytic activity and the sensitivity. Based on these results, hydrogen peroxide detection system was proposed by Pt nanozyme, and a serum glucose detection system was created. Compared with traditional blood glucose meters, its detection limit and linear range meet the needs of actual use, and it has more stable detection performance than natural enzymes.

1. Dreaden, E. C.; El-Sayed, M. A., Detecting and Destroying Cancer Cells in More Than One Way With Noble Metals and Different Confinement Properties on the Nanoscale[J], Acc Chem Res, 2012, 45(11): 1854-65.
2. Bortot, B.; Mongiat, M.; Valencic, E., et al., Nanotechnology-Based Cisplatin Intracellular Delivery to Enhance Chemo-Sensitivity of Ovarian Cancer[J], Int J Nanomedicine, 2020, 15: 4793-4810.
3. Xiong, X.; Tang, Y.; Xu, C., et al., High Carbonization Temperature to Trigger Enzyme Mimicking Activities of Silk-Derived Nanosheets[J], Small, 2020, 10.1002/smll.202004129: e2004129.
4. Choi, J. H.; Lee, J. H.; Son, J., et al., Noble Metal-Assisted Surface Plasmon Resonance Immunosensors[J], Sensors (Basel), 2020, 20(4): 1-19.
5. Lee, J. U.; Nguyen, A. H.; Sim, S. J., A Nanoplasmonic Biosensor for Label-Free Multiplex Detection of Cancer Biomarkers[J], Biosens Bioelectron, 2015, 74: 341-346.
6. Jia, K.; Khaywah, M. Y.; Li, Y., et al., Strong Improvements of Localized Surface Plasmon Resonance Sensitivity by Using Au/Ag Bimetallic Nanostructures Modified With Polydopamine Films[J], ACS Appl Mater Interfaces, 2014, 6(1): 219-227.
7. Ma, X.; Lin, Y.; Guo, L., et al., A Universal Multicolor Immunosensor for Semiquantitative Visual Detection of Biomarkers With the Naked Eyes[J], Biosens Bioelectron, 2017, 87: 122-128.
8. Zhang, Z.; Wang, H.; Chen, Z., et al., Plasmonic Colorimetric Sensors Based on Etching and Growth of Noble Metal Nanoparticles: Strategies and Applications[J], Biosens Bioelectron, 2018, 114: 52-65.
9. Wilson, A. J.; Willets, K. A., Surface-Enhanced Raman Scattering Imaging Using Noble Metal Nanoparticles[J], Wiley Interdiscip Rev Nanomed Nanobiotechnol, 2013, 5(2): 180-9.
10. Žukovskaja, O.; Agafilushkina, S.; Sivakov, V., et al., Rapid Detection of the Bacterial Biomarker Pyocyanin in Artificial Sputum Using a SERS-Active Silicon Nanowire Matrix Covered by Bimetallic Noble Metal Nanoparticles[J], Talanta, 2019, 202: 171-177.
11. Wang, X.; Wang, C.; Cheng, L., et al., Noble Metal Coated Single-Walled Carbon Nanotubes for Applications in Surface Enhanced Raman Scattering Imaging and Photothermal Therapy[J], Journal of the American Chemical Society, 2012, 134(17): 7414-7422.
12. Chen, Y.; Ma, T.; Liu, P., et al., NIR-Light-Activated Ratiometric Fluorescent Hybrid Micelles for High Spatiotemporally Controlled Biological Imaging and Chemotherapy[J], Small, 2020, 10.1002/smll.202005667: e2005667.
13. Shou, K.; Qu, C.; Sun, Y., et al., Multifunctional biomedical Imaging in Physiological and Pathological Conditions Using a NIR-II Probe[J], Adv Funct Mater, 2017, 27(23).
14. Huang, X.; El-Sayed, I. H.; Qian, W., et al., Cancer Cell Imaging and Photothermal Therapy in the Near-Infrared Region by Using Gold Nanorods[J], Journal of the American Chemical Society, 2006, 128(6): 2115-2120.
15. Wang, S.; Chen, K. J.; Wu, T. H., et al., Photothermal Effects of Supramolecularly Assembled Gold Nanoparticles for the Targeted Treatment of Cancer Cells[J], Angew Chem Int Ed Engl, 2010, 49(22): 3777-81.
16. Ding, X.; Liow, C. H.; Zhang, M., et al., Surface Plasmon Resonance Enhanced Light Absorption and Photothermal Therapy in the Second Near-Infrared Window[J], J Am Chem Soc, 2014, 136(44): 15684-93.
17. Younis, M. R.; An, R. B.; Yin, Y.-C., et al., Plasmonic Nanohybrid with High Photothermal Conversion Efficiency for Simultaneously Effective Antibacterial/Anticancer Photothermal Therapy[J], ACS Applied Bio Materials, 2019, 2(9): 3942-3953.
18. Xu, X.; Liu, X.; Tan, L., et al., Controlled-Temperature Photothermal and Oxidative Bacteria Killing and Acceleration of Wound Healing by Polydopamine-Assisted Au-Hydroxyapatite Nanorods[J], Acta Biomater, 2018, 77: 352-364.
19. Zheng, D.; Zhang, K.; Chen, B., et al., Flexible Photothermal Assemblies with Tunable Gold Patterns for Improved Imaging‐Guided Synergistic Therapy[J], Small, 2020, 16(34).
20. Liu, H.; Lin, W.; He, L., et al., Radiosensitive Core/Satellite Ternary Heteronanostructure for Multimodal Imaging-Guided Synergistic Cancer Radiotherapy[J], Biomaterials, 2020, 226: 119545.
21. Tao, C.; An, L.; Lin, J., et al., Surface Plasmon Resonance-Enhanced Photoacoustic Imaging and Photothermal Therapy of Endogenous H2S-Triggered Au@Cu2O[J], Small, 2019, 15(44): e1903473.
22. Yan, Y.; Xia, B. Y.; Zhao, B., et al., A Review on Noble-Metal-Free Bifunctional Heterogeneous Catalysts for Overall Electrochemical Water Splitting[J], Journal of Materials Chemistry A, 2016, 4(45): 17587-17603.
23. Guo, J.; Lin, C.; Jiang, C., et al., Review on Noble Metal-Based Catalysts for Formaldehyde Oxidation at Room Temperature[J], Applied Surface Science, 2019, 475: 237-255.
24. Huang, Y.; Ren, J.; Qu, X., Nanozymes: Classification, Catalytic Mechanisms, Activity Regulation, and Applications[J], Chem Rev, 2019, 119(6): 4357-4412.
25. 杨瑞韬. 基于g-C3N4的纳米酶设计合成及其抗菌性能研究[D], 广西, 广西师范大学, 2016.
26. Gao, L.; Zhuang, J.; Nie, L., et al., Intrinsic Peroxidase-Like Activity of Ferromagnetic Nanoparticles[J], Nat Nanotechnol, 2007, 2(9): 577-83.
27. Feng, Y.; Cheng, Y.; Chang, Y., et al., Time-Staggered Delivery of Erlotinib and Doxorubicin by Gold Nanocages With Two Smart Polymers for Reprogrammable Release and Synergistic With Photothermal Therapy[J], Biomaterials, 2019, 217: 119327.
28. Wang, M.; Chang, M.; Chen, Q., et al., Au2Pt-PEG-Ce6 Nanoformulation With Dual Nanozyme Activities for Synergistic Chemodynamic Therapy/Phototherapy[J], Biomaterials, 2020, 252: 120093.
29. He, W.; Liu, Y.; Yuan, J., et al., Au@Pt Nanostructures as Oxidase and Peroxidase Mimetics for Use In Immunoassays[J], Biomaterials, 2011, 32(4): 1139-1147.
30. Chen, X. M.; Lin, Z. J.; Chen, D. J., et al., Nonenzymatic Amperometric Sensing of Glucose by Using Palladium Nanoparticles Supported on Functional Carbon Nanotubes[J], Biosens Bioelectron, 2010, 25(7): 1803-8.
31. Jin, L.; Meng, Z.; Zhang, Y., et al., Ultrasmall Pt Nanoclusters as Robust Peroxidase Mimics for Colorimetric Detection of Glucose in Human Serum[J], ACS Appl Mater Interfaces, 2017, 9(11): 10027-10033.
32. Li, J.; Liu, W.; Wu, X., et al., Mechanism of pH-Switchable Peroxidase and Catalase-Like Activities of Gold, Silver, Platinum and Palladium[J], Biomaterials, 2015, 48: 37-44.
33. Cao, F.; Zhang, L.; Wang, H., et al., Defect-Rich Adhesive Nanozymes as Efficient Antibiotics for Enhanced Bacterial Inhibition[J], Angew Chem Int Ed Engl, 2019, 58(45): 16236-16242.
34. Feng, L.; Wu, X.; Ren, L., et al., Well-Controlled Synthesis Of Au@Pt Nanostructures by Gold-Nanorod-Seeded Growth[J], Chemistry, 2008, 14(31): 9764-71.
35. 夏清冬. 多功能贵金属纳米颗粒的设计合成及催化性能的研究[D], 哈尔滨, 哈尔滨师范大学, 2016.
36. Blosi, M.; Albonetti, S.; Ortelli, S., et al., Green and Easily Scalable Microwave Synthesis of Noble Metal Nanosols (Au, Ag, Cu, Pd) Usable as Catalysts[J], New J. Chem., 2014, 38(4): 1401-1409.
37. Fu, R.; Zhang, Y. W.; Li, H. M., et al., LW106, A Novel Indoleamine 2,3-Dioxygenase 1 Inhibitor, Suppresses Tumour Progression by Limiting Stroma-Immune Crosstalk and Cancer Stem Cell Enrichment in Tumour Micro-Environment[J], Br J Pharmacol, 2018, 175(14): 3034-3049.
38. Ma, T.; Zhang, P.; Hou, Y., et al., "Smart" Nanoprobes for Visualization of Tumor Microenvironments[J], Adv Healthc Mater, 2018, 7(20): e1800391.
39. Li, S.; Ge, Y.; Tiwari, A., et al., A Temperature-Responsive Nanoreactor[J], Small, 2010, 6(21): 2453-9.
40. Mitra, K.; Gautam, S.; Kondaiah, P., et al., The cis-Diammineplatinum(II) Complex of Curcumin: A Dual Action DNA Crosslinking and Photochemotherapeutic Agent[J], Angew Chem Int Ed Engl, 2015, 54(47): 13989-93.
41. Jiang, R.; Qin, F.; Ruan, Q., et al., Ultrasensitive Plasmonic Response of Bimetallic Au/Pd Nanostructures to Hydrogen[J], Advanced Functional Materials, 2014, 24(46): 7328-7337.
42. Ellis, E.; Zhang, K.; Lin, Q., et al., Biocompatible pH-Responsive Nanoparticles With a Core-Anchored Multilayer Shell of Triblock Copolymers for Enhanced Cancer Therapy[J], J Mater Chem B, 2017, 5(23): 4421-4425.
43. Ma, J.; Hu, Z.; Wang, W., et al., pH-Sensitive Reversible Programmed Targeting Strategy by the Self-Assembly/Disassembly of Gold Nanoparticles[J], ACS Appl Mater Interfaces, 2017, 9(20): 16767-16777.
44. Xia, H.; Li, F.; Hu, X., et al., pH-Sensitive Pt Nanocluster Assembly Overcomes Cisplatin Resistance and Heterogeneous Stemness of Hepatocellular Carcinoma[J], ACS Cent Sci, 2016, 2(11): 802-811.
45. Jiang, W.-L.; Fu, Q.-J.; Yao, B.-J., et al., Smart pH-Responsive Polymer-Tethered and Pd NP-Loaded NMOF as the Pickering Interfacial Catalyst for One-Pot Cascade Biphasic Reaction[J], ACS Applied Materials & Interfaces, 2017, 9(41): 36438-36446.
46. Zhang, R.; Wang, L.; Wang, X., et al., Acid-Induced In Vivo Assembly of Gold Nanoparticles for Enhanced Photoacoustic Imaging-Guided Photothermal Therapy of Tumors[J], Adv Healthc Mater, 2020, 9(14): e2000394.
47. Liang, P.; Wang, M.; Zhang, S., et al., pH-Triggered Conformational Change of Antp-Based Drug Delivery Platform for Tumor Treatment with Combined Photothermal Therapy and Chemotherapy[J], Adv Healthc Mater, 2019, 8(15): e1900306.
48. Guohua, H.; Hongyang, L.; Zhiming, J., et al., Study of Small-Cell Lung Cancer Cell-Based Sensor and Its Applications in Chemotherapy Effects Rapid Evaluation for Anticancer Drugs[J], Biosens Bioelectron, 2017, 97: 184-195.
49. Goos, J.; Cho, A.; Carter, L. M., et al., Delivery of Polymeric Nanostars for Molecular Imaging and Endoradiotherapy Through the Enhanced Permeability and Retention (EPR) effect[J], Theranostics, 2020, 10(2): 567-584.
50. Gao, Y.; Ahiabu, A.; Serpe, M. J., Controlled Drug Release from the Aggregation–Disaggregation Behavior of pH-Responsive Microgels[J], ACS Applied Materials & Interfaces, 2014, 6(16): 13749-13756.
51. Bray, F.; Ferlay, J.; Soerjomataram, I., et al., Global Cancer Statistics 2018: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries[J], CA Cancer J Clin, 2018, 68(6): 394-424.
52. Weber, J.; Bollepalli, L.; Belenguer, A. M., et al., An Activatable Cancer-Targeted Hydrogen Peroxide Probe for Photoacoustic and Fluorescence Imaging[J], Cancer Res, 2019, 79(20): 5407-5417.
53. Wu, H.; Liu, L.; Song, L., et al., Enhanced Tumor Synergistic Therapy by Injectable Magnetic Hydrogel Mediated Generation of Hyperthermia and Highly Toxic Reactive Oxygen Species[J], ACS Nano, 2019, 13(12): 14013-14023.
54. Yu, J.; Ma, X.; Yin, W., et al., Synthesis of PVP-Functionalized Ultra-Small MoS2 Nanoparticles With Intrinsic Peroxidase-Like Activity for H2O2 and Glucose Detection[J], RSC Advances, 2016, 6(84): 81174-81183.