基于栅藻延迟发光表征中药药性的方法学验证

对栅藻延迟发光定量化表征中药寒热药性的方法进行优化,并进行方法学验证。用YPMS-2生物光子测量仪检测栅藻激发延迟发光强度,对测得的激发延迟发光强度用Statistica 10.0软件进行线性拟合,得到表征栅藻性质的可靠参数K,用产自于道地产地的经典寒性中药黄芩作为样本,验证本研究方法的精密度、稳定性、重复性,并进行空白实验。栅藻最佳使用K值波动范围是2.81~3.89,本研究方法精密度高,重复性、稳定性良好,空白溶剂无干扰。     

Biophotonic methods in microcirculation imaging

Visible and near-infrared light, particularly in the wavelength region of 600–1100 nm, offer a window into human and animal tissues due to reduced scattering and absorption. We review the main biophotonic methods applied to visualisation and assessment of the microcirculation and document the progress made over the past 10 years in particular. Applications, particularly in human skin, are of special topical importance due to an improved knowledge of its role and its value as a surrogate for other organs in drug testing at a time when drug development is under severe pressure.     

The Use of a Whole Animal Biophotonic Model as a Screen for the Angiogenic Potential of Estrogenic Compounds

Background: Vascular endothelial growth factor (VEGF) is essential for normal vascular growth and development during wound repair. VEGF is estrogen responsive and capable of regulating its own receptor, vascular endothelial growth factor receptor-2 (VEGFR-2). Several agricultural pesticides (e.g., methoxychlor) have estrogenic potential that can initiate inappropriate physiological responses in estrogenic-sensitive tissues following exposure in vivo. Thus, the current study was designed to determine whether the VEGFR-2-Luciferase (Luc) reporter transgenic mouse is a useful model for evaluating estrogenic tendencies of methoxychlor by monitoring wound healing via VEGFR-2-mediated gene expression using bioluminescence and real-time imaging technology.Results: VEGFR-2-Luc gene activity peaked by d 7 (P<0.001) in all groups but was not different (P>0.05) between control and estrogen/methoxychlor exposed mice.Conclusions: Changes in VEGFR-2-Luc gene activity associated with the dermal wound healing process were able to be measured via photonic emission. The increase in vasculature recruitment and formation is paralleled by the increase of VEGFR-2-Luc activity with a peak on day 7. However, estrogen/methoxychlor did not significantly alter wound healing mediated VEGFR-2-Luc gene expression patterns compared to controls. This suggests that the VEGFR-2-Luc transgenic mouse wound model tested in this study may not be optimal for use as a screen for the angiogenic potential of estrogenic compounds.     

Photodynamic Cancer Therapy Using Wavelet Based Monte Carlo Computation of Light Absorption with a Genetic Algorithm

Objective: The method to treating cancer that combines light and light-sensitive drugs to selectively destroy tumour cells without harming healthy tissue is called photodynamic therapy (PDT). It requires accurate data for light dose distribution, generated with scalable algorithms. One of the benchmark approaches involves Monte Carlo (MC) simulations. This gives an accurate assessment of light dose distribution, but is very demanding in computation time, which prevents routine application for treatment planning. Methods: In order to resolve this problem, a design for MC simulation based on the gold standard software in biophotonics was implemented with a large modern wavelet based genetic algorithm search (WGAS). Result: The accuracy of the proposed method was compared to that with the standard optimization method using a realistic skin model. The maximum stop band attenuation of the designed LP, HP, BP and BS filters was assessed using the proposed WGAS algorithm as well as with other methods. Conclusion: In this paper, the proposed methodology employs intermediate wavelets which improve the diversification rate of the charged genetic algorithm search and that leads to significant improvement in design effort efficiency.     

Immunonanoshells for targeted photothermal ablation in medulloblastoma and glioma: an in vitro evaluation using human cell lines

We are developing a novel approach to specifically target malignant brain tumor cells for photothermal ablation using antibody-tagged, near infrared-absorbing gold-silica nanoshells, referred to as immunonanoshells. Once localized to tumor cells, these nanoshells are extremely efficient at absorbing near-infrared light and can generate sufficient heat to kill cancer cells upon exposure to laser light. In this study, we evaluated the efficacy of immunonanoshells in vitro against both medulloblastoma and high-grade glioma cell lines. We used an antibody against HER2 to target gold-silica nanoshells to medulloblastoma cells, since HER2 is frequently overexpressed in medulloblastoma. We show that treatment with HER2-targeted nanoshells, but not non-targeted nanoshells, followed by exposure to laser light, can induce cell death in the HER2-overexpressing medulloblastoma cell line Daoy.2, as well as the parental Daoy cell line, which expresses HER2 at a moderate level, but not in dermal fibroblasts that do not express HER2. In an analogous set of experiments, we conjugated gold-silica nanoshells to an antibody against interleukin-13 receptor-alpha 2 (IL13Rα2), an antigen that is frequently overexpressed in gliomas. We demonstrate that these immunonanoshells are capable of inducing cell death in two high-grade glioma cell lines that express IL13Rα2, U373 and U87, but not in A431 epidermoid carcinoma cells that do not express significant levels of IL13Rα2. We believe that the use of antibody-tagged gold-silica nanoshells to selectively target cancer cells presents a promising new strategy for the treatment of central nervous system tumors that will minimize the damage and resulting toxicity to the surrounding normal brain.     

量子点及其在生物光子学中的应用

目的:量子点(半导体纳米微晶体)作为一种新型荧光探针应用到生物光子学中已经引起了国内外科学工作者的极大关注。文章主要介绍了量子点发光的基本原理,量子点相对于有机荧光染料的优缺点,量子点的化学合成、官能团修饰以及与生物结合的方法,并列举了量子点的生物光子学应用中的实例。最后展望了量子点今后的研究方向。     

Innovative surgical guidance for label-free real-time parathyroid identification

Background

Difficulty in identifying the parathyroid gland during neck operations can lead to accidental parathyroid gland excisions and postsurgical hypocalcemia. A clinical prototype called as PTeye was developed to guide parathyroid gland identification using a fiber-optic probe that detects near-infrared autofluorescence from parathyroid glands as operating room lights remain on. An Overlay Tissue Imaging System was designed concurrently to detect near-infrared autofluorescence and project visible light precisely onto parathyroid gland location.

荧光标记及检测技术在中药大分子活性示踪中的应用

综述了近年来中药大分子荧光标记的方法及应用,探讨了生物光子学检测技术在中药大分子活性示踪中的潜在应用前景,对阐明中药大分子的作用机制、实现对混合未知多组分中药大分子的荧光标记提出新思路,具有重要的意义。     

Early detection of pancreatic cancers in liquid biopsies by ultrasensitive fluorescence nanobiosensors

Numerous proteases, such as matrix metalloproteinases (MMPs), cathepsins (CTS), and urokinase plasminogen activator (UpA), are dysfunctional (that is, over- or under-expressed) in solid tumors, when compared to healthy human subjects. This offers the opportunity to detect early tumors by liquid biopsies. This approach is of particular advantage for the early detection of pancreatic cancer, which is a “silent killer”. We have developed fluorescence nanobiosensors for ultrasensitive (sub-femtomolar) arginase and protease detection, consisting of water-dispersible Fe/Fe₃O₄ core/shell nanoparticles and two tethered fluorescent dyes: TCPP (Tetrakis(4-carboxyphenyl)porphyrin) and cyanine 5.5. Upon posttranslational modification or enzymatic cleavage, the fluorescence of TCPP increases, which enables the detection of proteases at sub-femtomolar activities utilizing conventional plate readers. We have identified an enzymatic signature for the detection of pancreatic adenocarcinomas in serum, consisting of arginase, matrix metalloproteinase-1, -3, and -?9, cathepsin-B and -E, urokinase plasminogen activator, and neutrophil elastase, which is a potential game-changer.     

Digital holographic imaging of dynamic cytoskeleton changes

A variety of physical and biochemical cell properties depends on the function and integrity of the actin cytoskeleton. The actin cytoskeleton mediates crucial cellular functions as migration, intracellular transport, exocytosis, endocytosis, cell stiffness and force generation. Highly dynamic actin fibers are therefore targets for several drugs and toxins. However, the study of actin interfering processes by standard microscopy techniques fails in the detailed resolution of dynamic spatial alterations required for a deeper understanding of toxic or drug effects. Here we applied digital holographic microscopy in the online functional analysis of the actin cytoskeleton changes of a highly differentiated and a dedifferentiated pancreas tumor cell line induced by the marine toxin Latrunculin B. Scanning electron microscopy (SEM) and fluorescence microscopy showed rapid Latrunculin B induced alterations in cell morphology and actin fiber degradation in both pancreatic tumor cell lines. In contrast digital holographic in vivo analysis of the drug dependent dynamic cellular processes revealed unequal changes in cell morphology. While tumor cells with a low metastatic potential showed Latrunculin B induced cell collapse within 4 h the metastatic tumor cells were resistant to Latrunculin B treatment. Spatial resolution of morphological alterations by digital holography detected so far unknown differences in the actin cytoskeleton stability of highly differentiated and dedifferentiated pancreas tumor cell lines. These data demonstrate that marker-free, non-destructive online analysis of cellular morphology and dynamic spatial processes in living cells by digital holography offers new insights in actin dependent cellular mechanisms. Digital holographic microscopy was shown to be a versatile tool in the screening of toxic drug effects and cancer cell biology.