Pei-Nan Wang
Fudan University
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Publication
Featured researches published by Pei-Nan Wang.
ACS Nano | 2010
Xi Wu; Tian Ming; Xin Wang; Pei-Nan Wang; Jianfang Wang; Ji-Yao Chen
Gold nanocubes demonstrate unique optical properties of the high photoluminescence (PL) quantum yield and a remarkably enhanced extinction band at 544 nm. The 4 x 10(-2) PL yield, which is about 200 times higher than that of gold nanorods, allows gold nanocubes to be successfully used in cell imaging of human liver cancer cells (QGY) and human embryo kidney cells (293T) with a common method of single-photon excitation. The high extinction coefficients of gold nanocubes also facilitate them carrying out the photothermal therapy of QGY and 293T cells, showing similar photokilling efficiency as compared to gold nanorods.
Physics in Medicine and Biology | 2006
Y L Jin; Ji-Yao Chen; Lei Xu; Pei-Nan Wang
The refractive index of biological tissue is a fundamental parameter in applications of optical diagnosis and laser treatments. In the present work, the refractive indices and thermo-optic coefficients of some basic biomaterials, such as blood plasma, haemoglobin solution and lipid membrane, were studied by the method of total internal reflection at the wavelengths of 532 and 632.8 nm that are the most frequently used laser wavelengths in the biomedical field. The effects of the sample concentration and the temperature on refractive index were measured, and empirical relationships were summarized, accompanied by a theoretical explanation based on molecular polarization theory. The results provide some fundamental data for the refractive indices of these biomaterials under variant conditions, and also demonstrate that the total internal reflection method is a feasible and reliable way to measure the refractive indices of biological samples.
Nanotechnology | 2006
J. Ma; Ji-Yao Chen; Jia Guo; Changchun Wang; Wuli Yang; L Xu; Pei-Nan Wang
The photostability of thiol-capped CdTe quantum dots (QDs) in Euglena gracilis (EG 277) and human embryonic kidney (HEK 293) cells was studied. The photobleaching for the cellular QDs is dependent both on the irradiation power density and the QD local concentration. The photostability of cellular QDs is better than that of chlorophyll in EG 277 cells and of green fluorescence protein (GFP) in HEK 293 cells, and is much better than that of FITC when the local concentration of QDs is not too low. The photobleaching of cellular QDs was remarkably reduced in the nitrogen treated EG 277 cells, indicating that photobleaching in living cells mainly results from photo-oxidation. The effect of photo-oxidation on QD photobleaching was further confirmed by comparing the situations in oxygen treated and nitrogen treated QD aqueous solutions. The photobleaching rate is related to the irradiation power density and the local density of QDs. The higher irradiation power density and oxygen abundance and lower QD concentration will result in a higher photobleaching rate.
Journal of Fluorescence | 2007
F. L. Xue; Ji-Yao Chen; Jia Guo; Changchun Wang; Wuli Yang; Pei-Nan Wang; Daru Lu
Quantum dots (QDs), as novel fluorescence probes, have shown a great potential for bio-molecular labeling and cellular imaging. To stain cellular targets, the sufficient intracellular delivery of QDs is required. In this work the tat, a typical membrane-permeable carrier peptide, was conjugated with thiol-capped CdTe QDs to form CdTe Tat-QDs, and the intracellular deliveries of CdTe QDs or CdTe Tat-QDs were compared in human hepatocellular carcinoma (QGY) cells and human breast cancer (MCF7) cells in vitro by means of confocal laser scanning microscopy. Added into the cell dishes, both QDs and Tat-QDs adhered to the outer leaflet of the plasma membrane of cells within a few minutes, but the binding amount of Tat-QDs was obviously higher than that of QDs. Then both QDs and Tat-QDs can penetrate into cells, and their cellular contents increased with incubation time but both saturated after 3 hours incubation. However the cellular levels of Tat-QDs were higher than those of QDs, with the ratio of 2.1 (±0.3) times in QGY cells and 1.5 (±0.2) times in MCF7 cells, demonstrating the enhancing effect of Tat conjugation on the intracellular delivery of QDs.
Applied Physics Letters | 2007
Lan Mi; Peng Xu; Hong Shen; Pei-Nan Wang; Weidian Shen
The energy band structures and density of states for N-doped and N:H-doped anatase TiO2 are calculated based on the first-principles density-functional theory. For N-doped TiO2, there appear two isolated states above the top of the valence band and the band gap narrowing is very small. With the same nitrogen dopant concentration, N:H doping yields a significant band gap narrowing. The calculated results support our experimental data that N:H-doped TiO2 exhibited higher visible-light photocatalytic efficiency than the N-doped one.
Nanoscale Research Letters | 2011
Zheng Li; Lan Mi; Pei-Nan Wang; Ji-Yao Chen
Nitrogen-doped TiO2 (N-TiO2) nanoparticles were prepared by calcining the anatase TiO2 nanoparticles under ammonia atmosphere. The N-TiO2 showed higher absorbance in the visible region than the pure TiO2. The cytotoxicity and visible-light-induced phototoxicity of the pure- and N-TiO2 were examined for three types of cancer cell lines. No significant cytotoxicity was detected. However, the visible-light-induced photokilling effects on cells were observed. The survival fraction of the cells decreased with the increased incubation concentration of the nanoparticles. The cancer cells incubated with N-TiO2 were killed more effectively than that with the pure TiO2. The reactive oxygen species was found to play an important role on the photokilling effect for cells. Furthermore, the intracellular distributions of N-TiO2 nanoparticles were examined by laser scanning confocal microscopy. The co-localization of N-TiO2 nanoparticles with nuclei or Golgi complexes was observed. The aberrant nuclear morphologies such as micronuclei were detected after the N-TiO2-treated cells were irradiated by the visible light.
Nanoscale Research Letters | 2009
Yu Zhang; Lan Mi; Rongling Xiong; Pei-Nan Wang; Ji-Yao Chen; Wuli Yang; Changchun Wang; Qian Peng
Internalization and dynamic subcellular distribution of thiol-capped CdTe quantum dots (QDs) in living cells were studied by means of laser scanning confocal microscopy. These unfunctionalized QDs were well internalized into human hepatocellular carcinoma and rat basophilic leukemia cells in vitro. Co-localizations of QDs with lysosomes and Golgi complexes were observed, indicating that in addition to the well-known endosome-lysosome endocytosis pathway, the Golgi complex is also a main destination of the endocytosed QDs. The movement of the endocytosed QDs toward the Golgi complex in the perinuclear region of the cell was demonstrated.
Colloids and Surfaces B: Biointerfaces | 2015
Xiaobo Pan; Jin Xie; Zheng Li; Maxin Chen; Mengyan Wang; Pei-Nan Wang; Li Chen; Lan Mi
As a second-generation photodynamic therapy (PDT) photosensitizer, aluminum phthalocyanine chloride tetrasulfonate (Pc) has gained great attention due to its high absorption at the red light region. Yet, its application in PDT is strongly limited by its low cellular uptake efficiency. In this report, nitrogen-doped TiO2 nanoparticles (N-TiO2) conjugated with Pc are synthesized by a two-step surface modification method. The N-TiO2-Pc products are characterized by Zeta potential, transmission electron microscopy and UV-vis absorption spectroscopy. The cellular uptake, intracellular distribution, cytotoxicity and the photokilling effect of the nanoparticles are studied on different cancer cell lines. Compared with Pc, the absorption spectrum of N-TiO2-Pc expands from red to UV region, resulting in a higher production of reactive oxygen species under visible light irradiation. In addition, the cellular uptake of Pc is largely improved by its carrier N-TiO2. The photokilling efficiency of N-TiO2-Pc is over ten times higher than that of Pc. The results suggest that N-TiO2-Pc is an excellent candidate as a photosensitizer in PDT.
Journal of Physical Chemistry B | 2010
Lei Li; Ji-Yao Chen; Xi Wu; Pei-Nan Wang; Qian Peng
Hexadecyltrimethylammonium bromide-coated gold nanorods (AuNRs) with positive charges were effectively bound to negatively charged sulfonated aluminum phthalocyanine (AlPcS), a photosensitizer for photodynamic detection and therapy, due to the electrostatic force, with a loading content of 10(4) AlPcS molecules per rod. A 5-fold increase in the AlPcS fluorescence of the AlPcS-AuNRs complex was seen. The excitation fluorescence spectrum of the AlPcS-AuNRs with a typical 520 nm band fits well with the resonance band of AuNR surface plasmons, suggesting that such increased AlPcS fluorescence is produced from the strong surface plasmons of AuNRs. The intracellular distribution of AlPcS-AuNRs was studied in the QGY liver cancer cells by respectively imaging the AlPcS fluorescence and AuNRs reflectance with a confocal microscope. Furthermore, the AlPcS-AuNRs-loaded cells were photodynamically damaged after being exposed to red light in a light-dose-dependent manner. In contrast, no phototoxicity of the cells was seen after incubation with the same amount of free AlPcS, indicating that the AlPcS-AuNRs can enhance the AlPcS-mediated photodynamic effect. In addition, the loaded AlPcS can be photothermally released from AuNRs in the cells by the irradiation with an 800 nm femtosecond laser, demonstrating the potential for controlled drug release.
Nanotechnology | 2007
Jia He; Ji-Yao Chen; Pu Wang; Pei-Nan Wang; Jia Guo; Wuli Yang; Changchun Wang; Qian Peng
Poly(N-isopropylacrylamide) (PNIPAM)-coated Fe3O4@SiO2@CdTe multifunctional nanoparticles with photoluminescent (PL), thermosensitive and magnetic properties, were investigated as carriers to deliver water-soluble, fluorescent sulfonated Zn-phthalocyanine (ZnPcS), a photosensitizing drug for photodynamic therapy of cancer, in Chinese hamster ovary (CHO) cells in vitro and zebra fish in vivo. PNIPAM is a well-known thermo-responsive polymer with a volume phase transition temperature. This property allows it to be swollen in water at temperatures lower than 32?34??C to take up ZnPcS and shrunken to expel the drug at higher temperatures. Since the PL band of CdTe quantum dots (QDs) as indicators for the nanoparticles is at 585?nm and the emission band of ZnPcS is at 680?nm, it is possible to study the temperature-dependent release of ZnPcS from the nanoparticles by fluorescence measurements. ZnPcS was embedded in the PNIPAM of the nanoparticles at 25??C in phosphate buffered saline (PBS) solution and released at 37??C, measured with a spectrophotometer. When CHO cells had been incubated with the ZnPcS-loaded nanoparticles at 27??C, a similar intracellular localization pattern of CdTe QDs and ZnPcS was seen by multichannel measurements in confocal laser scanning microscopy (CLSM), but a diffuse pattern of only ZnPcS fluorescence was detected in the cytoplasm of the cells at 37??C, indicating a release of ZnPcS from the nanoparticles. Similar results were also found in the intestinal tract of zebra fish in vivo after intake of the nanoparticles. Since the nanoparticles contain magnetic (Fe3O4) material, the nanoparticles could also be manipulated to change their location in the intestinal tract of the zebra fish with an external magnetic field gradient of 300?G?mm?1. The results presented suggest that such multifunctional nanoparticles may have combined potential for temperature-dependent drug delivery, QD photodetection and magnetic manipulation in diagnosis and therapy of diseases.