Pengping Xu

Biodegradable Core-shell Dual-Metal-Organic-Frameworks Nanotheranostic Agent for Multiple Imaging Guided Combination Cancer Therapy

Metal-organic-frameworks (MOFs) possess high porosity, large surface area, and tunable functionality are promising candidates for synchronous diagnosis and therapy in cancer treatment. Although large number of MOFs has been discovered, conventional MOF-based nanoplatforms are mainly limited to the sole MOF source with sole functionality. In this study, surfactant modified Prussian blue (PB) core coated by compact ZIF-8 shell (core-shell dual-MOFs, CSD-MOFs) has been reported through a versatile stepwise approach. With Prussian blue as core, CSD-MOFs are able to serve as both magnetic resonance imaging (MRI) and fluorescence optical imaging (FOI) agents. We show that CSD-MOFs crystals loading the anticancer drug doxorubicin (DOX) are efficient pH and near-infrared (NIR) dual-stimuli responsive drug delivery vehicles. After the degradation of ZIF-8, simultaneous NIR irradiation to the inner PB MOFs continuously generate heat that kill cancer cells. Their efficacy on HeLa cancer cell lines is higher compared with the respective single treatment modality, achieving synergistic chemo-thermal therapy efficacy. In vivo results indicate that the anti-tumor efficacy of CSD-MOFs@DOX+NIR was 7.16 and 5.07 times enhanced compared to single chemo-therapy and single thermal-therapy respectively. Our strategy opens new possibilities to construct multifunctional theranostic systems through integration of two different MOFs.

Novel Metal Polyphenol Framework for MR Imaging-Guided Photothermal Therapy

Phothermal therapy has received increasing attention in recent years as a potentially effective way to treat cancer. In pursuit of a more biocompatible photothermal agent, we utilize biosafe materials including ellagic acid (EA), polyvinylpyrrolidone (PVP), and iron element as building blocks, and we successfully fabricate a homogeneous nanosized Fe-EA framework for the first time by a facile method. As expected, the novel nanoagent exhibits no obvious cytotoxicity and good hemocompatibility in vitro and in vivo. The microenvironment responsiveness to both pH and hydrogen peroxide makes the NPs biodegradable in tumor tissues, and the framework should be easily cleared by the body. Photothermal potentials of the nanoparticles are demonstrated with relevant features of strong NIR light absorption, moderately effective photothermal conversion efficiency, and good photothermal stability. The in vivo photothermal therapy also achieved effective tumor ablation with no apparent toxicity. On the other hand, it also exhibits T2 MR imaging ability originated from ferric ions. Our work highlights the promise of the Fe-EA framework for imaging-guided photothermal therapy.

Inclusion phenomena of clove oil with α-, β-, γ- and heptakis (2,6-di-O-methyl)-β-cyclodextrin

Inclusion interactions of α-, β-, γ- and heptakis (2,6-di-O-methyl)-β-cyclodextrin (DMβ-CD) as hosts with clove oil (an impure eugenol, I-Eug) as guest in aqueous solution were investigated by fluorescence emission spectra. The binding constants of different hosts to I-Eug in aqueous solution decreased in the order: γ- > β- > DMβ- > α-CD. Two solid supramolecular inclusion complexes, I-Eug–β-CD and I-Eug–γ-CD, were prepared and characterised by nuclear magnetic resonance, powder X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis. All the results proved the formation of I-Eug–CD. The inclusion differences between I-Eug and pure eugenol were discussed. The relative contents of the main component eugenol (Eug), second component (eugenol acetate, Eua) and others in I-Eug were found to be fairly different before and after being included by β-CD, according to the data obtained from high performance liquid chromatography. This could be a practical method to extract the effective components (Eug and Eua) from I-Eug.

Photo-Enhanced Singlet Oxygen Generation of Prussian Blue-based Nanocatalyst for Imaging-Guided Augmented Photodynamic Therapy

Summary Therapeutic effects of photodynamic therapy (PDT) remain largely limited because of tumor hypoxia. Herein, we report safe and versatile nanocatalysts (NCs) for endogenous oxygen generation and imaging-guided enhanced PDT. The NCs (named as PSP) are prepared by coating Prussian blue (PB) with mesoporous silica to load photosensitizer (zinc phthalocyanine, ZnPc), followed by the modification of polyethylene glycol chains. The inner PB not only acts like a catalase for hydrogen peroxide decomposition but also serves as a photothermal agent to increase the local temperature and then speed up the oxygen supply under near-infrared irradiation. The loaded ZnPc can immediately transform the formed oxygen to generate cytotoxic singlet oxygen upon the same laser irradiation due to the overlapped absorption between PB and ZnPc. Results indicate that the PSP-ZnPc (PSPZP) NCs could realize the photothermally controlled improvement of hypoxic condition in cancer cells and tumor tissues, therefore demonstrating enhanced cancer therapy by the incorporation of PDT and photothermal therapy.

Ultrasmall Ru/Cu-doped RuO2 Complex Embedded in Amorphous Carbon Skeleton as Highly Active Bifunctional Electrocatalysts for Overall Water Splitting

Developing highly active electrocatalysts with superior durability for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in the same electrolyte is a grand challenge to realize the practical application of electrolysis water for producing hydrogen. In this work, an ultrasmall Ru/Cu-doped RuO2 complex embedded in an amorphous carbon skeleton is synthesized, through thermolysis of Ru-modified Cu-1,3,5-benzenetricarboxylic acid (BTC), as a highly efficient bifunctional catalyst for overall water splitting electrocatalysis. The ultrasmall Ru nanoparticles in the complex expose more activity sites for hydrogen evolution and outperform the commercial Pt/C. Meanwhile, the ultrasmall RuO2 nanoparticles exhibit superior oxygen evolution performance over commercial RuO2, and the doping of Cu into the ultrasmall RuO2 nanoparticles further enhances the oxygen evolution performance of the catalyst. The outstanding OER and decent HER catalytic activity endow the complex with impressive overall water splitting performance superior to that of the state-of-the-art electrocatalysts, which just require 1.47 and 1.67 V to achieve a current density of 10 mA cm-2 and 100 mA cm-2. The density functional theory calculations reveal that a Cu dopant could effectively tailor the d-band center, thereby tuning electronic structure of Ru activity sites on the RuO2 (110) plane and ultimately improving the OER performance of RuO2.

In Situ One-Pot Synthesis of MOF-Polydopamine Hybrid Nanogels with Enhanced Photothermal Effect for Targeted Cancer Therapy

Abstract Herein, a simple one‐pot way is designed to prepare a type of multifunctional metal–organic framework (MOF)‐based hybrid nanogels by in situ hybridization of dopamine monomer in the skeleton of MnCo. The resultant hybrid nanoparticles (named as MCP) show enhanced photothermal conversion efficiency in comparison with pure polydopamine or MnCo nanoparticles (NPs) synthesized under a similar method and, therefore, show great potential for photothermal therapy (PTT) in vivo. The MCP NPs are expected to possess T 1 positive magnetic resonance imaging ability due to the high‐spin Mn‐N6 (S = 5/2) in the skeleton of MnCo. To improve the therapy efficiency as a PTT agent, the MCP NPs are further modified with functional polyethylene glycol (PEG) and thiol terminal cyclic arginine–glycine–aspartic acid peptide, respectively: the first one is to increase the stability, biocompatibility, and blood circulation time of MCP NPs in vivo; the second one is to increase the tumor accumulation of MCP‐PEG NPs and improve their therapeutic efficiency as photothermal agent.

Photoluminescence distinction of lung adenocarcinoma cells A549 and squamous cells H520 using metallothionein expression in response to Cd-doped Mn3[Co(CN)6]2 nanocubes

Luminescent Mn3[Co(CN)6]2 nanocubes doped with Cd2+ can induce human lung adenocarcinoma cells A549 generating more metallothioneins (MTs) than squamous cells H520. The nanocubes can be bound to MTs and be excluded from cells for detoxification. Then A549 cells have a lower fluorescence imaging intensity than H520 cells, which can distinguish the two kinds of cells.