Fu Shiyan, Wang Shu, Zhang Xiaodi, Qi Anhui, Liu Zhirong, Yu Xin, Chen Chuanfang, Li Linlin
Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, PR China.
Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, 100190, PR China.
Colloids Surf B Biointerfaces. 2017 Jun 1;154:239-245. doi: 10.1016/j.colsurfb.2017.03.038. Epub 2017 Mar 18.
Ferromagnetic nanoparticles (FeO NPs) have been proven to have the intrinsic peroxidase-like activity. This property has been used for analyte detection, tumor tissue visualization, and cancer therapy, etc. However, the effect of particle structure and morphology on its peroxidase-like activity has been rarely reported. In this work, we fabricated FeO nanoparticles with different structures (nanoclusters, nanoflowers, and nanodiamonds) by facilely tuning the pH values in the hydrothermal reaction. Their in vitro peroxidase-like activity was evaluated via chromogenic reaction of 3,3',5,5'-tetramethylbenzidine (TMB) by the reduction of HO to HO. It was found the nanostructures had a great influence on their peroxidase-like activity, following the order of nanoclusters>nanoflowers>nanodiamonds. With this activity, the peroxidase-like activity of FeO NPs was used for cancer therapy with the addition of low-concentration HO. The cancer cell-killing activity was due to the intracellular generated reactive oxygen species (ROS) after endocytosis of FeO NPs into the Hela cells. It was interesting that the cell killing ability of these three kinds of FeO NPs was not consistent with the in vitro enzyme-like activity. It was deduced that the cell endocytosis of the nanoparticles along with their enzyme-like activity co-determined their cancer cell-killing performance.
铁磁性纳米颗粒（FeO NPs）已被证明具有内在的类过氧化物酶活性。这一特性已被用于分析物检测、肿瘤组织可视化和癌症治疗等。然而，颗粒结构和形态对其类过氧化物酶活性的影响鲜有报道。在这项工作中，我们通过在水热反应中轻松调节pH值，制备了具有不同结构（纳米团簇、纳米花和纳米金刚石）的FeO纳米颗粒。通过3,3',5,5'-四甲基联苯胺（TMB）的显色反应，通过将HO还原为HO来评估它们的体外类过氧化物酶活性。发现纳米结构对其类过氧化物酶活性有很大影响，顺序为纳米团簇>纳米花>纳米金刚石。利用这种活性，在添加低浓度HO的情况下，FeO NPs的类过氧化物酶活性被用于癌症治疗。癌细胞杀伤活性归因于FeO NPs内吞进入Hela细胞后细胞内产生的活性氧（ROS）。有趣的是，这三种FeO NPs的细胞杀伤能力与体外酶活性不一致。据推测，纳米颗粒的细胞内吞作用及其类酶活性共同决定了它们的癌细胞杀伤性能。
