pH-Driven Targeting Nanoprobe with Dual-Responsive Drug Release for Persistent Luminescence Imaging and Chemotherapy of Tumor.

Multifunctional nanoprobes with both imaging and drug delivery capabilities represent an emerging approach to the diagnosis and treatment of tumor. However, poor accumulation in tumor cells and low drug availability are the main limitations for their further application. Here we show a pH-driven targeting nanoprobe with dual-responsive drug release for persistent luminescence imaging and chemotherapy of tumor. The nanoprobe is constructed by conjugating the pH-low-insertion-peptide (pHLIP) to the surface of the core-shell structure of mesoporous silica-coated persistent luminescence nanoparticles (MSPLNPs) with the peptide GFLG and disulfide bond as bridges. The pHLIP functionalized nanoprobe exhibits higher cellular uptake for A549 and HepG2 cells in an acidic extracellular microenvironment (pH < 6.5) than in normal physiological condition (pH 7.4). The nanoprobe possesses well-defined NIR persistent luminescence performance and can be effectively accumulated in the tumor site, leading to the visual HepG2 tumor target imaging without autofluorescence interference. Furthermore, the nanoprobe realizes the dual-responsive release of doxorubicin loaded in the mesoporous channels in systems containing cathepsin B and glutathione, and can effectively kill tumor cells and inhibit the growth of tumor. This integrated nanoprobe possesses great potential for the diagnosis and treatment of tumors with high specificity and efficiency.

Liposome-Coated Persistent Luminescence Nanoparticles as Luminescence Trackable Drug Carrier for Chemotherapy.

Near-infrared persistent luminescence nanoparticles (NIR-PLNPs) are promising imaging agents due to deep tissue penetration, high signal-to-noise ratio, and repeatedly charging ability. Here, we report liposome-coated NIR-PLNPs (Lipo-PLNPs) as a novel persistent luminescence imaging guided drug carrier for chemotherapy. The Lipo-PLNP nanocomposite shows the advantages of superior persistent luminescence and high drug loading efficiency and enables autofluorescence-free and long-term tracking of drug delivery carriers with remarkable therapeutic effect.

Fabrication of magnetic polydopamine@naphthyl microporous organic network nanosphere for efficient extraction of hydroxylated polycyclic aromatic hydrocarbons and p-nitrophenol from wastewater samples.

Herein, we report the fabrication of a novel, well-defined core-double-shell-structured magnetic Fe3O4@polydopamine@naphthyl microporous organic network (MON), Fe3O4@PDA@NMON, for the efficient magnetic extraction of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and p-nitrophenol (p-Npn) from wastewater samples. The hierarchical nanospheres were designed and constructed with the Fe3O4 nanoparticle core, the inner shell of a polydopamine (PDA) layer, and the outer shell of a porous naphthyl MON (NMON) coating, allowing efficient and synergistic extraction of OH-PAHs and p-Npn via hydrophobic, hydrogen bonding, and π-π interactions. The Fe3O4@PDA@NMON nanospheres were well characterized and employed as an efficient sorbent for magnetic solid-phase extraction (MSPE) coupled with high performance liquid chromatography (HPLC) for analyzing of OH-PAHs and p-Npn. Under optimal conditions, the Fe3O4@PDA@NMON-based-MSPE-HPLC-UV method afforded wide linear range (0.18-500 µg L-1), low limits of detection (0.070 µg L-1 for p-Npn, 0.090 µg L-1 for 2-OH-Nap, 0.090 µg L-1 for 9-OH-Fluo and 0.055 µg L-1 for 9-OH-Phe, respectively), large enrichment factors (92.6-98.4), good precisions (intra-day and inter-day relative standard deviations (RSDs); <6.4%, n=6) and less consumption of the adsorbent. Furthermore, trace OH-PAHs and p-Npn with concentrations of 0.29-0.80 µg L-1 were successfully detected in various wastewater samples. Fe3O4@PDA@NMON also functioned as a good adsorbent to enrich a wide scope of trace contaminants containing hydrogen bonding sites and aromatic structures, highlighting the potential of functional MONs in sample pretreatment.

Fabrication of polyethyleneimine modified magnetic microporous organic network nanosphere for efficient enrichment of non-steroidal anti-inflammatory drugs from wastewater samples prior to HPLC-UV analysis.

Development of novel functionalized adsorbents for efficient magnetic solid phase extraction (MSPE) is essential for promoting their versatile applications in sample pretreatment. Herein, we report the fabrication of a new polyethyleneimine-600 decorated magnetic microporous organic network nanosphere (Fe3O4@MON-PEI600) for effective MSPE of trace non-steroidal anti-inflammatory drugs (NSAIDs) from different water samples. The core-shelled Fe3O4@MON-PEI600 integrates the synergistic effects of Fe3O4, MON and PEI600, providing facile and effective extraction to NSAIDs via multiple hydrogen bonding, π-π and hydrophobic interactions. The inner MON shell employs π-π and hydrophobic interaction sites and the outer PEI-600 coat acts as the hydrogen bonding doner/receptor, which affords good extraction performance for NSAIDs. Under optimal conditions, the Fe3O4@MON-PEI600-MSPE-HPLC-UV method gives wide linear range (0.14-400 µg L-1), low limits of detection (0.042-0.149 µg L-1), good precisions (intra-day and inter-day RSDs < 4.5%, n = 6), and large enrichment factors (97.0-98.2). Extraction mechanisms and selectivity of Fe3O4@MON-PEI600 are evaluated in detail. Moreover, Fe3O4@MON-PEI600 is successfully applied to enrich the trace NSAIDs in different water samples with the concentrations of 0.7 and 0.8 µg L-1 for 1-naphthylacetic acid, 0.5 and 0.1 µg L-1 for naproxen as well as 0.7 µg L-1 for ibuprofen, respectively. The developed method not only affords a novel and efficient magnetic adsorbent for NSAIDs in aqueous media at trace level, but also provides a new strategy for the rational design and synthesis of multiple functionalized MON composites in sample pretreatment.

Polysiloxane assisted fabrication of chiral crystal sponge coated capillary column for chiral gas chromatographic separation.

Chiral crystalline sponges (CCSs) are a recent class of chiral porous metal complexes potential in chiral recognition. Here we report the fabrication of polysiloxane OV-1701 incorporated CCS-3S (PSO/CCS-3S) coated capillary column as a novel stationary phase for gas chromatographic separation of diverse racemates. CCS-3S with the chiral ligand of (S)-mandelic was selected as the model CCS. With the aid of polysiloxane OV-1701, PSO/CCS-3S coated capillary column gave improved resolution, broader enantiomers separation scope and much larger McReynolds constants than CCS-3S coated capillary column. Many racemates that cannot be separated on CCS-3S coated capillary column were well resolved on PSO/CCS-3S coated capillary column. The PSO/CCS-3S coated capillary column also gave wide linear range, low limit of detection, good repeatability and reproducibility, and fine inertness and anti-column bleeding properties for the separation of enantiomers. In addition, the PSO/CCS-3S coated capillary column presented better resolution for the studied racemates than commercial ß-cyclodextrin based Cyclosil B (30 m long ×0.32 mm i.d. × 0.25 µm film thickness), ß-DEX 225 (30 m long ×0.25 mm i.d. × 0.25 µm film thickness) and amino acid based Chirasil L-Val (25 m long ×0.25 mm i.d. × 0.12 µm film thickness) capillary columns. These results indicate the great potential of PSO/CCS-3S coated capillary column in separation of enantiomers.

A multifunctional persistent luminescent nanoprobe for imaging guided dual-stimulus responsive and triple-synergistic therapy of drug resistant tumor cells.

We report the design and fabrication of a multifunctional persistent luminescent nanoprobe for imaging guided dual-stimulus responsive and triple-synergistic therapy of drug resistant tumor. The integration of the dual-stimulus of an acidic microenvironment and laser irradiation with the triple-synergistic therapy of doxorubicin, photothermal and siRNA offers excellent therapeutic performance for drug resistant tumor cells with high specificity and little side effects.

Advances in covalent organic frameworks in separation science.

Covalent organic frameworks (COFs) are a new class of multifunctional crystalline organic polymer constructed with organic monomers via robust covalent bonds. The unique properties such as convenient modification, low densities, large specific surface areas, good stability and permanent porosity make COFs great potential in separation science. This review shows the state-of-the art for the application of COFs and their composites in analytical separation science. COFs and their composites have been explored as promising sorbents for solid phase extraction, potential coatings for solid phase microextraction, and novel stationary phases for gas chromatography, high-performance liquid chromatography and capillary electrochromatography. The prospects of COFs for separation science are also presented, which can offer an outlook and reference for further study on the applications of COFs.

Methacrylate-bonded covalent-organic framework monolithic columns for high performance liquid chromatography.

Covalent-organic frameworks (COFs) are a newfangled class of intriguing microporous materials. Considering their unique properties, COFs should be promising as packing materials for high performance liquid chromatography (HPLC). However, the irregular shape and sub-micrometer size of COFs synthesized via the traditional methods render the main obstacles for the application of COFs in HPLC. Herein, we report the preparation of methacrylate-bonded COF monolithic columns for HPLC to overcome the above obstacles. The prepared COF bonded monolithic columns not only show good homogeneity and permeability, but also give high column efficiency, good resolution and precision for HPLC separation of small molecules including polycyclic aromatic hydrocarbons, phenols, anilines, nonsteroidal anti-inflammatory drugs and benzothiophenes. Compared with the bare polymer monolithic column, the COF bonded monolithic columns show enhanced hydrophobic, π-π and hydrogen bond interactions in reverse phase HPLC. The results reveal the great potential of COF bonded monoliths for HPLC and COFs in separation sciences.

Radiopaque tantalum oxide coated persistent luminescent nanoparticles as multimodal probes for in vivo near-infrared luminescence and computed tomography bioimaging.

The design and fabrication of multimodal imaging nanoparticles is of great importance in medical diagnosis. Here we report the fabrication of core-shell structured Zn2.94Ga1.96Ge2O10:Cr(3+),Pr(3+)@TaOx@SiO2 nanoparticles for persistent luminescence and X-ray computed tomography (CT) imaging. Persistent luminescent nanoparticles Zn2.94Ga1.96Ge2O10:Cr(3+),Pr(3+) were used as the core to provide near-infrared luminescence, and a TaOx layer was grown on the core to serve as the contrast agent for CT. The tenuous outermost SiO2 shell was fabricated on the TaOx layer to gain high biocompatibility and to facilitate post-modification with tumor-targeting peptides. The fabricated core-shell structured nanoparticle shows intense near-infrared luminescence and the CT contrast effect. No obvious mutual interference was found in these two modalities, which ensures that each imaging modality merits could be brought in a full play. Furthermore, covalent bonding of cyclic-Asn-Gly-Arg peptides makes the core-shell structured nanoparticles promising for in vivo targeted imaging of tumor-bearing mice.

Fabrication of metal-organic framework MIL-88B films on stainless steel fibers for solid-phase microextraction of polychlorinated biphenyls.

Metal-organic frameworks (MOFs) have received considerable attention as novel sorbents for sample preparation due to their fascinating structures and functionalities such as large surface area, good thermal stability, and uniform structured nanoscale cavities. Here, we report the application of a thermal and solvent stable MOF MIL-88B with nanosized bipyramidal cages and large surface area for solid-phase microextraction (SPME) of polychlorinated biphenyls (PCBs). Novel MIL-88B coated fiber was fabricated via an in situ hydrothermal growth of MIL-88B film on etched stainless steel fiber. The MIL-88B coated fiber gave large enhancement factors (757-2243), low detection limits (0.45-1.32ngL(-1)), and good linearity (5-200ngL(-1)) for PCBs. The relative standard deviation (RSD) for six replicate extractions of PCBs at 100ngL(-1) on MIL-88B coated fiber ranged from 4.2% to 8.7%. The recoveries for spiked PCBs (10ngL(-1)) in water and soil samples were in the range of 79.7-103.2%. Besides, the MIL-88B coated fiber was stable enough for 150 extraction cycles without significant loss of extraction efficiency. The developed method was successfully applied to the determination of PCBs in water samples and soil samples.

Metal-organic framework UiO-66 coated stainless steel fiber for solid-phase microextraction of phenols in water samples.

Effective solid-phase microextraction (SPME) of polar phenols from water samples is usually difficult due to the strong interaction between polar phenols and aqueous matrix. Here, we report the fabrication of a metal-organic framework UiO-66 coated stainless steel fiber via physical adhesion for the SPME of polar phenols (phenol, o-cresol, p-cresol, 2,6-dimethylphenol, 2,4-dichlorophenol and 2,6-dichlorophenol) in water samples before gas chromatographic separation with flame ionic detection. Headspace SPME of 10mL sample solution with the fabricated UiO-66 coated fiber gave the enhancement factors of 160 (phenol) - 3769 (2,4-dichlorophenol), and the linear ranges of 1-1000µgL(-1) (2,6-dimethylphenol, 2,4-dichlorophenol and 2,6-dichlorophenol), 1-500µgL(-1) (o-cresol and p-cresol) and 5-500µgL(-1) (phenol). The detection limits ranged from 0.11µgL(-1) (2,6-dimethylphenol) to 1.23µgL(-1) (phenol). The precision (relative standard deviations, RSDs) for six replicate determinations of the analytes at 100µgL(-1) using a single UiO-66 coated fiber ranged from 2.8% to 6.2%. The fiber-to-fiber reproducibility (RSDs) for three parallel UiO-66 coated fibers varied from 5.9% to 10%. The recoveries obtained by spiking 5µgL(-1) of the phenols in the water samples ranged from 80% to 115%.

Incorporation of metal-organic framework UiO-66 into porous polymer monoliths to enhance the liquid chromatographic separation of small molecules.

UiO-66 incorporated monoliths were fabricated to enhance the liquid chromatographic separation of small molecules with high column efficiency and good reproducibility.