SHG-enhanced NIR-excited in vitro photodynamic therapy using composite nanoparticles of barium titanate and rose Bengal.

Near infrared (NIR) light excited photodynamic therapy (PDT) has been considered as a possible way to increase the therapy depth. Besides the traditional two-photon excited PDT and upconversion PDT by rare-earth ion materials, SHG has drawn much attention recently to act as an additional choice to achieve NIR light excited PDT. Herein, by using the electrostatic absorption method, barium titanate and rose Bengal composite nanoparticles (BT@PAH/RB/PAH, BT-RB) were synthesized. Compared with rose Bengal (RB) molecules and a mixture of barium titanate nanoparticles and RB (BT + RB), BT-RB nanoparticles were shown to be able to produce more reactive oxygen species (ROS) ex vivo and in vitro. Afterwards, the SHG-enhanced localized PDT was applied on Hela cells, in which BT-RB nanoparticles showed a better performance than BT + RB. Our work has shown that the SHG-enhanced PDT has good prospects and the close combination of harmonic nanoparticles and photosensitizers may facilitate the development of novel reagents for NIR light excited PDT.

NIR-II fluorescence in vivo confocal microscopy with aggregation-induced emission dots.

Significantly reduced tissue scattering of fluorescence signals in the second near-infrared (NIR-II, 1,000-1,700 nm) spectral region offers opportunities for large-depth in vivo bioimaging. Nowadays, most reported works concerning NIR-II fluorescence in vivo bioimaging are realized by wide-field illumination and 2D-arrayed detection (e.g., via InGaAs camera), which has high temporal resolution but limited spatial resolution due to out-of-focus signals. Combining NIR-II fluorescence imaging with confocal microscopy is a good approach to achieve high-spatial resolution visualization of biosamples even at deep tissues. In this presented work, a NIR-II fluorescence confocal microscopic system was setup. By using a kind of aggregation-induced emission (AIE) dots as NIR-II fluorescent probes, 800 µm-deep 3D in vivo cerebrovascular imaging of a mouse was obtained, and the spatial resolution at 700 µm depth could reach 8.78 µm. Moreover, the time-correlated single photon counting (TCSPC) technique and femtosecond laser excitation were introduced into NIR-II fluorescence confocal microscopy, and in vivo confocal NIR-II fluorescence lifetime microscopic imaging (FLIM) of mouse cerebral vasculature was successfully realized.

Aggregation-Induced Emission Nanoparticles Encapsulated with PEGylated Nano Graphene Oxide and Their Applications in Two-Photon Fluorescence Bioimaging and Photodynamic Therapy in Vitro and in Vivo.

Aggregation-induced emission (AIE) nanoparticles have been shown promise for fluorescence bioimaging and photodynamic therapy due to the good combination of nanoparticles and organic dyes or photosensitizers. Among several kinds of AIE nanoparticles, those that are capsulated with nanographene oxides (NGO) are easy to make, size-tunable, and have proven to be very stable in deionized water. However, the stability in saline solution still needs improvement for further applications in chemical or biomedical fields, and the efficacy of photodynamic therapy using NGO-capsulate AIE photosensitizers has not been evaluated yet. Herein, we modified NGO with polyethylene glycol (PEG) to improve the stability of NGO-capsulated AIE nanoparticles in phosphate buffer saline. Furthermore, by combining this modification method with a dual-functional molecule which has both typical AIE property and photosensitizing ability, we performed both two-photon fluorescence bioimaging and photodynamic therapy in vitro and in vivo. Our work shows that AIE nanoparticles capsulated with PEGylated nanographene oxide can be a powerful tool for future bioimaging and photodynamic therapy applications.

Low photobleaching and high emission depletion efficiency: the potential of AIE luminogen as fluorescent probe for STED microscopy.

We present a preliminary study which explores the potential of aggregation-induced emission (AIE) luminogen as a new fluorescent probe for STED microscopy. Compared with Coumarin 102, which is a commonly used organic fluorophore in STED microscopy, HPS, a typical AIE luminogen, is more resistant to photobleaching. In addition, HPS-doped nanoparticles have higher emission depletion efficiency than Coumarin 102 in organic solution. These two advantages of AIE luminogen can facilitate the improvement of spatial resolution, as well as long-term imaging, in STED microscopy. AIE luminogen will be a promising candidate for STED microscopy in the future.

[Design and realization of a microarray data analysis platform].

OBJECTIVE: To design a platform for microarray data analysis and processing in the browser/server mode running in Linux operating system. METHODS: Based on the Apache HTTP server, the platform, programmed with Perl language, integrated R language and Bioconductor packages for processing and analysis of the input data of oligonucleotide arrays and two-color spotted arrays. Users were allowed to submit data and parameter configurations to the platform via the web page, and the results of analysis were also returned via the web page. RESULTS: With an easy operation and high performance, the platform fulfilled the functions of processing, quality assessment, biological annotation and statistical analysis of the data from oligonucleotide arrays and two-color spotted arrays. Using the platform, we analyzed the gene expression profiles in Mtb-stimulated macrophages of three clinical phenotypes, namely latent TB (LTB), pulmonary (PTB) and meningeal (TBM), and obtained valuable clues for identifying tuberculosis susceptibility genes. We also analyzed the effect of INH treatment on Mycobacterium tuberculosis gene expression in various dormancy models, such as hypoxia and KatG mutant, and found that a set of genes responded to INH treatment during exponential growth but not in dormancy, and that the overall number of differentially regulated genes was reduced in the cells in low metabolic state. CONCLUSION: The platform we have constructed integrates comprehensive resources, and with a user-friendly interface, allows direct result visualization to facilitate microarray data analysis.

[Design and construction of the platform for comparative genomics].

OBJECTIVE: To design a versatile genome comparison and visualization platform based on browser/server mode supported by a local server. METHODS: The server of the platform was Apache HTTP server. Perl was used to integrate such genome alignment package and algorithms as MUMmer, LAGAN, and Mauve for different comparison purposes, and the users could submit data and parameters to the platform via the web page. The results of analysis were also returned via the web page. RESULTS: The platform could handle multiple data input formats, compare complete and draft genome sequence, alignment pair-wise or multi genome of more divergent species, identify regions of high similarity, locate local nucleotide mutations and large-scale recombination, and display the results by visualization interface. Analysis of the homology of 10 new strains of influenza A virus indicated that PB1 gene might evolve from human H3N2 viruses, PB2 and PA genes from avian H3N2 viruses, and HA and NS genes from swine H1N1 viruses. Alignment of Mycobacterium tuberculosis (H37Rv, CDC1551) and Mycobacterium bovis (AF2122/97) genomes revealed that sequence insertion/deletion and duplication were the major source of genomic differences. CONCLUSION: The platform integrate comprehensive resources with a user-friendly interface and intuitive result visualization to facilitate conventional study of comparative genomics.