Developing nanotherapeutic system with combined antitumor capability has increasingly become a promising strategy for cancer treatment. Herein, we present a biodegradable iron-doped ZIF-8 based nanoconstruct to integrate merits of chemodynamic therapy, photothermal therapy and chemotherapy into ‘‘all-in-one’’ nanoplatform. Specifically, the nanoconstruct is assembled by loading chemotherapeutic drug (doxorubicin, DOX) and photothermal transforming agent (indocyanine green, ICG) into Fe 2+ -doped ZIF-8 nanocrystals . Benefiting from the intrinsic pH-responsive property, the ZIF-8 nanoconstruct can be degraded easily in the typically acidic tumor microenvironment or cancer cells, leading to smart tumor microenvironment-responsive Fe 2+ , DOX and ICG release at high-rate. Particularly, the ZIF-8 nanoconstruct can release Fe 2+ rather than Fe 3+ of lower Fenton catalytic activity, leading to efficient Fenton reaction to generate abundant hydroxyl radical (·OH) for chemodynamic therapy. The released DOX and ICG demonstrate exceptional chemotherapy and near infrared laser triggered photothermal therapy capability with high photothermal conversion efficiency (35.9%), respectively. In turn, the photothermal therapy can significantly enhance the chemodynamic therapy effect. The as-designed nanoconstruct with synergistic therapeutic efficacy provide a fatality rate as high as 93.7% for cancer cells, which is promising for efficient cancer eradication.
Li Jiacheng,Tian Tian,Jia Yannan,Xu Nannan,Yang Shujun,Zhang Chenyue,Gao Shiwei,Shen Wei,Wang Zheng
Herein, an iron-doped ZIF-8-loaded multi-walled carbon nanotube (FZM) was synthesized and its adsorption performance on tetracycline (TC) was investigated. The experimental conditions (solution pH, temperature, adsorbent dose) were optimized by Box–Behnken design (BBD) in response surface methodology (RSM). The results show that the adsorption effect of TC by FZM is optimal under the conditions of temperature = 298 K, pH = 6, and contact time = 360 min. The adsorption processes of TC by FZM follow the pseudo-second-order (PSO) kinetic and Freundlich isotherm models, indicating that chemisorption is the dominant factor and the adsorption reaction is multi-layer, with a theoretical maximum saturation capacity of 1111.11 mg/g at 298 K. The adsorption thermodynamic results indicate that the adsorption of TC by FZM is a spontaneous and endothermic process. The mechanism of TC adsorption by FZM possibly occurs through hydrogen bonding, surface complexation, π–π interaction, and electrostatic interaction. From the statistical results, the optimal adsorption capacity of TC by FZM is 599.78 mg/g at a pH of 7.1, a temperature of 312.5 K, and an adsorbent dose of 64.43 mg/L, with a deviation of 1.73% from the actual value. Furthermore, regeneration experiments demonstrate that FZM has excellent reusability with a 15% loss of adsorption capacity after four cycles. This study provides some insights to study the adsorption behavior of TC by MOFs and the optimization of the adsorption experimental conditions, and also shows the potential of FZM for TC removal.
Feiyu Li,Peipei Zhu,Bingzhu Zheng,Zijie Lu,Chao Fang,Yike Fu,Xiang Li
Intrinsic characteristics of microorganisms, including non-specific metabolism sites, toxic byproducts and uncontrolled proliferation constrain their exploitation in medical applications such as tumor therapy. Here, we report an engineered biohybrid that can efficiently target cancerous sites through a pre-determined metabolic pathway to enable precise tumor ablation. In this system, DH5α Escherichia coli is engineered by the introduction of hypoxia-inducible promoters and lactate oxidase genes, and further surface-armored with iron-doped ZIF-8 nanoparticles. This bioengineered E. coli can produce and secrete lactate oxidase to reduce lactate concentration in response to hypoxic tumor microenvironment, as well as triggering immune activation. The peroxidase-like functionality of the nanoparticles extends the end product of the lactate metabolism, enabling the conversion of hydrogen peroxide (H 2 O 2 ) into highly cytotoxic hydroxyl radicals. This, coupled with the transformation of tirapazamine loaded on nanoparticles to toxic benzotriazinyl, culminates in severe tumor cell ferroptosis. Intravenous injection of this biohybrid significantly inhibited tumor growth and metastasis. This article is protected by copyright. All rights reserved
危险品化学品经营许可证（带存储）