Mao Wei, Kim Song Rae, Yoo Hyuk Sang
Department of Biomedical Materials Engineering, Kangwon National University Chuncheon 24341 Republic of Korea
Chuncheon Center, Korea Basic Science Institute Chuncheon 24341 Republic of Korea.
RSC Adv. 2020 Oct 7;10(61):37040-37049. doi: 10.1039/d0ra06622b.
Gold nanoparticles (AuNPs) are the predominant and representative metal nano-carriers used for the tumor-targeted delivery of therapeutics because they possess advantages such as biocompatibility, high drug loading efficiency, and enhanced accumulation at tumor sites the size-dependent enhanced permeability and retention (EPR) effect. In this study, we designed an AuNP functionalized with block polymers comprising polyethylenimine and azide group-functionalized poly(ethyl glycol) for the electrostatic incorporation of cytosine-guanine oligonucleotide (CpG ODN) on the surface. The ODN-incorporated AuNPs were cross-linked to gold nanoparticle clusters (AuNCs) click chemistry using a matrix metalloproteinase (MMP)-2 cleavable peptide linker modified with alkyne groups at both ends. In the presence of Cu(i), azide groups and alkyne groups spontaneously cyclize to form a triazole ring with high fidelity and efficiency, and therefore allow single AuNPs to stack to larger AuNCs for increased EPR effect-mediated tumor targeting. H-NMR and Fourier transform infrared spectroscopy revealed the successful synthesis of an azide-PEG-grafted branched polyethylenimine, and the size and morphology of AuNPs fabricated by the synthesized polymer were confirmed to be 4.02 ± 0.45 nm by field emission-transmission electron microscopy. Raman spectroscopy characterization demonstrated the introduction of azide groups on the surface of the synthesized AuNPs. Zeta-potential and gel-retardation analysis of CpG-loaded AuNPs indicated complete CpG sequestration by AuNPs when the CpG : AuNP weight ratio was higher than 1 : 2.5. The clustering process of the CpG-loaded AuNPs was monitored and was demonstrated to be dependent on the alkyne linker-to-AuNP ratio. Thus, the clicked AuNC can be tailored as a gene carrier where a high accumulation of therapeutics is required.
金纳米颗粒（AuNPs）是用于肿瘤靶向治疗药物递送的主要且具有代表性的金属纳米载体，因为它们具有生物相容性、高药物负载效率以及在肿瘤部位因尺寸依赖性增强的渗透和滞留（EPR）效应而实现的增强积累等优点。在本研究中，我们设计了一种用包含聚乙烯亚胺和叠氮基官能化聚（乙二醇）的嵌段聚合物功能化的AuNP，用于在表面静电掺入胞嘧啶 - 鸟嘌呤寡核苷酸（CpG ODN）。通过使用两端用炔基修饰的基质金属蛋白酶（MMP）-2可裂解肽接头，将掺入ODN的AuNPs通过点击化学交联到金纳米颗粒簇（AuNCs）上。在Cu（I）存在下，叠氮基和炔基自发环化形成具有高保真度和效率的三唑环，因此允许单个AuNPs堆叠成更大的AuNCs，以增强EPR效应介导的肿瘤靶向。氢核磁共振（H-NMR）和傅里叶变换红外光谱表明成功合成了叠氮基-聚乙二醇接枝的支化聚乙烯亚胺，并且通过场发射透射电子显微镜确认由合成聚合物制备的AuNPs的尺寸和形态为4.02±0.45纳米。拉曼光谱表征证明了在合成的AuNPs表面引入了叠氮基。对负载CpG的AuNPs的zeta电位和凝胶阻滞分析表明，当CpG与AuNP的重量比高于1:2.5时，AuNPs完全螯合了CpG。监测了负载CpG的AuNPs的聚集过程，并证明其取决于炔基接头与AuNP的比例。因此，点击后的AuNC可以被定制为需要高治疗药物积累的基因载体。
