Dataset Information

Simultaneous Sensing of Seven Pathogenic Bacteria by Guanidine-Functionalized Upconversion Fluorescent Nanoparticles.

ABSTRACT: The method capable of simultaneously detecting multiple target bacterial pathogens is necessary and of great interest. In this research, we demonstrated our initial effort to simultaneously detect seven common foodborne bacteria by developing a straightforward upconversion fluorescence sensing approach. The fluorescent nanosensor was constructed from a designed guanidine-functionalized upconversion fluorescent nanoparticles (UCNPs@GDN), tannic acid, and hydrogen peroxide (HP) and could quantify pathogenic bacteria in a nonspecific manner because the luminescence of the upconversion fluorescent nanoparticle was effectively strengthened in the presence of bacteria. When the developed nanosensor was applied to quantify multiple bacteria including Escherichia coli, Salmonella, Cronobacter sakazakii, Shigella flexneri, Vibrio parahaemolyticus, Staphylococcus aureus, and Listeria monocytogenes, a linear range of 10³ to 10⁸ cfu mL^-1 and a detection limit of 1.30 × 10² cfu mL^-1 have been obtained for the seven model mixture bacteria. In addition, the similar linear range and detection limit were also obtained for the detection of single bacteria. The present approach also exhibited acceptable recovery values ranging from 70.0 to 118.2% for bacteria in real samples (water, milk, and beef). All these results suggested that the guanidine-functionalized upconversion fluorescent nanosensor could be considered as a promising candidate for the rapid detection and surveillance of microbial pollutants in food and water.

SUBMITTER: Yin M

PROVIDER: S-EPMC6648614 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

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Simultaneous Sensing of Seven Pathogenic Bacteria by Guanidine-Functionalized Upconversion Fluorescent Nanoparticles.

Yin Mingyuan M Wu Chen C Li Haijie H Jia Zhixin Z Deng Qiliang Q Wang Shuo S Zhang Yukui Y

ACS omega 20190523 5

The method capable of simultaneously detecting multiple target bacterial pathogens is necessary and of great interest. In this research, we demonstrated our initial effort to simultaneously detect seven common foodborne bacteria by developing a straightforward upconversion fluorescence sensing approach. The fluorescent nanosensor was constructed from a designed guanidine-functionalized upconversion fluorescent nanoparticles (UCNPs@GDN), tannic acid, and hydrogen peroxide (HP) and could quantify ...[more]

PMID: 31459983

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Project description:Water-soluble upconversion nanoparticles (UCNPs) that exhibit significant ultraviolet, blue, and red emissions under 980-nm laser excitation were successfully synthesized for performing near infrared (NIR)-triggered photodynamic therapy (PDT). The lanthanide-doped UCNPs bearing oleate ligands were first exchanged by citrates to generate polyanionic surfaces and then sequentially encapsulated with NH₂-terminated poly(amido amine) (PAMAM) dendrimers (G4) and chlorine6 (Ce6) using a layer-by-layer (LBL) absorption strategy. Transmission electron microscopy and X-ray diffraction analysis confirm that the hybrid UCNPs possess a polygonal morphology with an average dimension of 16.0 ± 2.1 nm and α-phase crystallinity. A simple calculation derived through thermogravimetric analysis revealed that one polycationic G4 dendrimer could be firmly accommodated by approximately 150 polyanionic citrates through multivalent interactions. Moreover, zeta potential measurements indicated that the LBL fabrication results in the hybrid nanoparticles with positively charged surfaces originated from these dendrimers, which assist the cellular uptake in biological specimens. The cytotoxic singlet oxygen based on the photosensitization of the adsorbed Ce6 through the upconversion emissions can be readily accumulated by increasing the irradiation time of the incident lasers. Compared with that of 660-nm lasers, NIR-laser excitation exhibits optimized in vitro PDT effects toward human breast cancer MCF-7 cells cultured in the tumorspheres, and less than 40% of cells survived under a low Ce6 dosage of 2.5 × 10-7 M. Fluorescence microscopy analysis indicated that the NIR-driven PDT causes more effective destruction of the cells located inside spheres that exhibit significant cancer stem cell or progenitor cell properties. Moreover, an in vivo assessment based on immunohistochemical analysis for a 4T1 tumor-bearing mouse model confirmed the effective inhibition of cancer cell proliferation through cellular DNA damage by the expression of Ki67 and γH2AXser139 protein markers. Thus, the hybrid UCNPs are a promising NIR-triggered PDT module for cancer treatment.

Project description:Therapeutic efficacy of glioblastoma multiforme (GBM) is often severely limited by poor penetration of therapeutics through blood-brain barrier (BBB) into brain tissues and lack of tumor targeting. In this regard, a functionalized upconversion nanoparticle (UCNP)-based delivery system which can target brain tumor and convert deep tissue-penetrating near-infrared (NIR) light into visible light for precise phototherapies on brain tumor was developed in this work. Methods: The UCNP-based phototherapy delivery system was acquired by assembly of oleic acid-coated UCNPs with angiopep-2/cholesterol-conjugated poly(ethylene glycol) and the hydrophobic photosensitizers. The hybrid nanoparticles (ANG-IMNPs) were characterized by DLS, TEM, UV/vis and fluorescence spectrophotometer. Cellular uptake was examined by laser scanning confocal microscopy and flow cytometry. The PDT/PTT effect of ANG-IMNPs was evaluated using MTT assay. Tumor accumulation of NPs was determined by a non-invasive in vivo imaging system (IVIS). The in vivo anti-glioma effect of ANG-IMNPs was evaluated by immunohistochemical (IHC) examination of tumor tissues and Kaplan-Meier survival analysis. Results: In vitro data demonstrated enhanced uptake of ANG-IMNPs by murine astrocytoma cells (ALTS1C1) and pronounced cytotoxicity by combined NIR-triggered PDT and PTT. In consistence with the increased penetration of ANG-IMNPs through endothelial monolayer in vitro, the NPs have also shown significantly enhanced accumulation at brain tumor by IVIS. The IHC tissue examination confirmed prominent apoptotic and necrotic effects on tumor cells in mice receiving targeted dual photo-based therapies, which also led to enhanced median survival (24 days) as compared to the NP treatment without angiopep-2 (14 days). Conclusion: In vitro and in vivo data strongly indicate that the ANG-IMNPs were capable of selectively delivering dual photosensitizers to brain astrocytoma tumors for effective PDT/PTT in conjugation with a substantially improved median survival. The therapeutic efficacy of ANG-IMNPs demonstrated in this study suggests their potential in overcoming BBB and establishing an effective treatment against GBM.

Dataset Information

Simultaneous Sensing of Seven Pathogenic Bacteria by Guanidine-Functionalized Upconversion Fluorescent Nanoparticles.

Publications

Simultaneous Sensing of Seven Pathogenic Bacteria by Guanidine-Functionalized Upconversion Fluorescent Nanoparticles.

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