Wansong Chen

Black Phosphorus Nanosheet-Based Drug Delivery System for Synergistic Photodynamic/Photothermal/Chemotherapy of Cancer.

A black phosphorus (BP)-based drug delivery system for synergistic photodynamic/photothermal/chemotherapy of cancer is constructed. As a 2D nanosheet, BP shows super high drug loading capacity and pH-/photoresponsive drug release. The intrinsic photothermal and photodynamic effects of BP enhance the antitumor activities. The synergistic photodynamic/photothermal/chemotherapy makes BP-based drug delivery system a multifunctional nanomedicine platform.

A naphthalimide-based azo colorimetric and ratiometric probe: synthesis and its application in rapid detection of cyanide anions

A naphthalimide-based azo dye (1) used as a colorimetric and ratiometric probe for the detection of CN− was synthesized by incorporating a salicylaldehyde moiety, which acts as a recognition unit, to the naphthalimido diazonium salt. Upon reacting with CN−, probe 1 displays dramatic colour changes rapidly from yellowish to red, corresponding to the absorption band shift from 408 nm to 497 nm. The colorimetric probe allows ratiometric detection of CN− with a linear range of 2–45 μM and a LOD (limit of detection) of 0.4 μM. In the optimized H2O/DMSO (7/3, v/v) mixed solvent, probe 1 displays excellent selectivity for CN− over other anions. In addition, 1 was successfully employed to prepare the filter paper-based test strips which can be used to monitor CN− conveniently, and the discernible concentration of CN− can be as low as 20 μM.

Black Phosphorus Nanosheets as a Neuroprotective Nanomedicine for Neurodegenerative Disorder Therapy

Transition-metal dyshomeostasis is recognized as a critical pathogenic factor at the onset and progression of neurodegenerative disorder (ND). Excess transition-metal ions such as Cu2+ can catalyze the generation of cytotoxic reactive oxygen species and thereafter induce neuronal cell apoptosis. Exploring new chelating agents, which are not only capable of capturing excess redox-active metal, but can also cross the blood-brain barrier (BBB), are highly desired for ND therapy. Herein, it is demonstrated that 2D black phosphorus (BP) nanosheets can capture Cu2+ efficiently and selectively to protect neuronal cells from Cu2+ -induced neurotoxicity. Moreover, both in vitro and in vivo studies show that the BBB permeability of BP nanosheets is significantly improved under near-infrared laser irradiation due to their strong photothermal effect, which overcomes the drawback of conventional chelating agents. Furthermore, the excellent biocompatibility and stability guarantee the biosafety of BP in future clinical applications. Therefore, these features make BP nanosheets have the great potential to work as an efficient neuroprotective nanodrug for ND therapy.

A ratiometric fluorescent probe with excited-state intramolecular proton transfer for benzoyl peroxide

A novel ratiometric fluorescent probe A1, based on excited-state intramolecular proton transfer (ESIPT) mechanism, for the detection of benzoyl peroxide (BPO) was designed and synthesized. A1 was employed for determining BPO in food and pharmaceutical samples with good sensitivity and high selectivity.

A label-free sensitive method for membrane protein detection based on aptamer and AgNCs transfer

Recently, membrane proteins have been considered as candidate cancer biomarkers and drug targets, due to their important roles in numerous physiological processes. Therefore, a facile, sensitive and quantitative detection of the membrane proteins is crucial for better understanding their roles in cancer cells and further validating their function in clinical research. We report a highly facile and sensitive detection method for membrane proteins on living cells in situ based on membrane protein-triggered release of cytosine (C)-rich single-stranded DNA (ssDNA) sequences, and the subsequent silver nanoclusters (AgNCs) transfer from polymer to C-rich ssDNA. The high-quantum yield and stable DNA-AgNCs allow the accurate detection of membrane proteins with facile operations and a common fluorescence spectrophotometer. The detection of protein tyrosine kinase-7 (PTK7), a membrane protein model, displays a response range from 30pM to 2nM with a detection limit of 12pM. The expression of PTK7 on single Hela cell and CCRF-CEM cell was calculated to be 7.5 × 10-19mol and 1.8 × 10-18mol, respectively. Given the simple and facile operation of this method, this detection platform can be applied as a universal strategy for ultrasensitive detection of membrane protein on cell in situ.

Unraveling the Hydrolysis of Merocyanine-Based Probes in Biological Assay

Merocyanine dyes, owing to their unique photochemical properties, are widely used to fabricate probes for the detection of biologically active small molecules and bioimaging. In this paper, merocyanine-based probes were proved of undergoing unwanted hydrolysis. To explore the strategies toward avoiding the hydrolysis, the detailed hydrolysis mechanism was first investigated, which was also confirmed by density functional theory (DFT) calculation. Then a series of merocyanine dyes were rationally designed. Influences of molecular structures of the probes, the analytical media such as pH and components of the solution on the hydrolysis were systematically studied. The experimental results suggest that merocyanine based probes with low electron density are more likely to suffer the hydrolysis, which could be exacerbated by the well-accepted strategy for constructing type-II probes. It is worth noting that chemical surroundings could also exert distinctive influence on the hydrolysis. The hydrolysis could be obviously aggravated when fetal calf serum or DMSO was deployed. Our findings will definitely provide an effective and reliable approach for guiding the rational design of highly robust merocyanine-based probes and the optimization of the analytical media, which is helpful in terms of avoiding the hydrolysis of the probes and hydrolysis caused analytical errors.

Dual Roles of Protein as a Template and a Sulfur Provider: A General Approach to Metal Sulfides for Efficient Photothermal Therapy of Cancer

Fabrication of clinically translatable nanoparticles (NPs) as photothermal therapy (PTT) agents against cancer is becoming increasingly desirable, but still challenging, especially in facile and controllable synthesis of biocompatible NPs with high photothermal efficiency. A new strategy which uses protein as both a template and a sulfur provider is proposed for facile, cost-effective, and large-scale construction of biocompatible metal sulfide NPs with controlled structure and high photothermal efficiency. Upon mixing proteins and metal ions under alkaline conditions, the metal ions can be rapidly coordinated via a biuret-reaction like process. In the presence of alkali, the inert disulfide bonds of S-rich proteins can be activated to react with metal ions and generate metal sulfide NPs under gentle conditions. As a template, the protein can confine and regulate the nucleation and growth of the metal sulfide NPs within the protein formed cavities. Thus, the obtained metal sulfides such as Ag2 S, Bi2 S3 , CdS, and CuS NPs are all with small size and coated with proteins, affording them biocompatible surfaces. As a model material, CuS NPs are evaluated as a PTT agent for cancer treatment. They exhibit high photothermal efficiency, high stability, water solubility, and good biocompatibility, making them an excellent PTT agent against tumors. This work paves a new avenue toward the synthesis of structure-controlled and biocompatible metal sulfide NPs, which can find wide applications in biomedical fields.

Bright and photostable fluorescent probe with aggregation-induced emission characteristics for specific lysosome imaging and tracking.

We develop a new lysosome-targeting AIE fluorescent probe tetraphenylethene-morpholine (TPE-MPL), by incorporating a typical lysosome-targeting moiety of morpholine into a stable tetraphenylethene skeleton. Due to both the AIE and antenna effects, TPE-MPL possesses superior photostability, appreciable tolerance to microenvironment change and high lysosome targeting ability. Our findings confirm that TPE-MPL is a well-suited imaging agent for targeting lysosome and tracking dynamic movement of lysosome. Moreover, due to its synthetic accessibility, TPE-MPL could be further modified as a dual-functional probe for lysosome, thereby gain further insight into the role of lysosome in biomedical applications.

Marriage of artificial catalase and black phosphorus nanosheets for reinforced photodynamic antitumor therapy

Two dimensional (2D) semiconducting nanomaterials have shown great potential for antitumor therapy. However, their clinical applications are seriously hampered by the tumour microenvironments. Bearing this in mind, we propose to improve the performance of 2D semiconducting nanomaterials using artificial catalase. In this work, we decorate black phosphorus (BP) nanosheets with Pt nanoparticles (NPs) through an in situ growth strategy. Pt NPs as artificial catalases can efficiently decompose the accumulated H2O2 in tumours to relieve tumour hypoxia, and thereafter improve the photodynamic antitumor activity of BP nanosheets. This work paves a new avenue for the functionalization of 2D semiconducting nanomaterials, which will promote the development of 2D semiconductor based nanodrugs.

Biomimetic nanothylakoids for efficient imaging-guided photodynamic therapy for cancer

Biomimetic nanothylakoids, which are constructed from the thylakoid membrane of vegetable leaves, show high efficiency in tumor microenvironment modulation and photodynamic antitumor therapy under near infrared fluorescence guidance. Furthermore, their outstanding biosafety, facile preparation and low cost make nanothylakoids suitable for further clinical applications.