Department of Medical Biomaterials Engineering, Kangwon National University, Chuncheon 200-701, Republic of Korea.
Department of Chemistry, Kangwon National University, Chuncheon 200-701, Republic of Korea.
J Control Release. 2015 Nov 10;217:64-73. doi: 10.1016/j.jconrel.2015.08.037. Epub 2015 Aug 24.
Gold nanoparticles (AuNPs) and quantum dots (Qdots) were clicked into doxorubicin nanoclusters that showed enzyme-dependent dissociation behaviors for differential cellular uptakes and imaging. The AuNPs were co-functionalized with doxorubicin (DOX) and azide-terminated polymer (DOX/azide@AuNP), while an enzyme-cleavable peptide and alkyne-terminated polymer were sequentially conjugated on Qdot surface (Alkyne-MMP@Qdot). Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and fluorescence imaging detected the azide and alkyne groups on DOX/azide@AuNP and Alkyne-MMP@Qdot, respectively, and the click-reactivity was also confirmed. In the presence of the catalyst, two nanoparticles were clicked to doxorubicin nanoclusters, which increased the volume of the particles ca. 343-fold within 30min. Upon matrix metalloproteinase-2 (MMP-2) digestion, the nanoclusters were clearly dissociated into smaller particles, and the fluorescence of the quenched Qdot was also recovered, which suggests that the nanoclusters respond to MMP-2 concentrations and can thus be employed for cancer imaging. Confocal microscopy and an elemental analysis of the cancer cells revealed that the cellular uptakes of doxorubicin nanoclusters significantly increased at higher MMP-2 concentrations, and doxorubicin could also be cleaved for anti-cancer effects. In vivo and in vitro cytotoxicity assay accordingly showed that the cytotoxicity of doxorubicin nanoclusters against cancer cells increased in MMP-2-rich environments such as tumor site. Thus, these nanoclusters containing DOX/azide@AuNP and Alkyne-MMP@Qdot are expected to be multifunctional carriers for targeted anti-cancer treatments and imaging.
金纳米粒子（AuNPs）和量子点（Qdots）被点击成阿霉素纳米簇，这些纳米簇表现出酶依赖性解离行为，从而实现了细胞摄取和成像的差异。AuNPs 与阿霉素（DOX）和叠氮端聚合物（DOX/azide@AuNP）共功能化，而酶可切割的肽和炔基端聚合物则依次接枝在 Qdot 表面（Alkyne-MMP@Qdot）。傅里叶变换红外光谱（FTIR）、拉曼光谱和荧光成像分别检测到 DOX/azide@AuNP 和 Alkyne-MMP@Qdot 上的叠氮和炔基基团，并且点击反应也得到了证实。在催化剂存在的情况下，两种纳米粒子被点击成阿霉素纳米簇，在 30min 内，颗粒体积增加了约 343 倍。在基质金属蛋白酶-2（MMP-2）消化后，纳米簇明显解离成更小的颗粒，被猝灭的 Qdot 的荧光也得到恢复，这表明纳米簇对 MMP-2 浓度有响应，因此可用于癌症成像。共聚焦显微镜和癌细胞的元素分析表明，在更高的 MMP-2 浓度下，阿霉素纳米簇的细胞摄取量显著增加，并且阿霉素也可以被切割以发挥抗癌作用。相应的体内和体外细胞毒性试验表明，在 MMP-2 丰富的环境（如肿瘤部位）中，阿霉素纳米簇对癌细胞的细胞毒性增加。因此，这些包含 DOX/azide@AuNP 和 Alkyne-MMP@Qdot 的纳米簇有望成为针对癌症治疗和成像的多功能载体。
