Photoacoustic Effect of Near-Infrared Absorbing Organic Molecules via Click Chemistry.

Near-infrared dyes were developed to be contrast agents due to their ability to improve the productivity of photoacoustic (PA) imaging and photothermal therapy (PTT) treatments. During the article, we described in detail the PA and PT effects of a category of organic molecules. F4-TCNQ could potentially cause a red-shift in the peak PA intensity. The results show that the PTT intensity of the near-infrared dyes with phenyl groups were higher than near-infrared dyes with thiophene groups. We also investigated the photodynamic treatment effect of C1b to demonstrate that these dyes are highly desirable in biochemistry. The high photoacoustic intensity of the organic molecules and the good yield of reactive oxygen species could indicate that these dyes have good potential for a wide range of imaging applications. Finally, we embedded the dye (C1b) in a liposomal hydrophobic phospholipid bilayer (C1b⊂L) to facilitate the application of hydrophobic dyes in biomedical applications, which can be absorbed by cells with good compatible and high stability for the imaging of cellular PA.

Nonlinear Optical and Ion Sensor Properties of Novel Molecules Conjugated by Click Chemistry.

The molecular structure, luminescence behavior, and electronic energy level of an organic optoelectronic materials are important parameters for its synthesis. The electro-optical properties can be changed by modifying the structure of the molecule to make the electronic energy level adjustable. In this article, a series of organic conjugated micro-molecules are successfully synthesized by linking small compound units. This metal-free [2 + 2] click chemistry process generates donor-acceptor chromophore substances with high yield, high solubility, and adjustable energy levels, which can be widely used for sensors and nonlinear optics in different fields. A-TCNE, A-TCNQ, and A-F4-TCNQ molecules are characterized comprehensively via UV-Vis-NIR spectra, 1H NMR spectra, infrared spectroscopy, and mass spectrometry. The unique nonlinear optical phenomena and powerful intra-molecular charge-transfer interactions of these new materials give them fascinating potential for application as optoelectronic materials.

HPLC determination of thiopurine nucleosides and nucleotides in vivo in lymphoblasts following mercaptopurine therapy.

BACKGROUND: Mercaptopurine is a prodrug requiring intracellular activation to thiopurine nucleotides to exert antileukemic effect. We developed a reversed-phase liquid chromatographic assay for the quantification of mercaptopurine, thioguanine, and methylmercaptopurine nucleoside and nucleotide concentrations in the target tissue, the leukemic lymphoblast. METHODS: Leukemic blasts were isolated from peripheral blood and bone marrow by a standard Ficoll-hypaque procedure. Proteins were removed by ultrafiltration in the presence of dithiothreitol. Thiopurine ribonucleotides were converted into their respective ribonucleosides by treatment of ultrafiltrate with acid phosphatase. Thiopurine nucleosides and bases were measured by direct injection of ultrafiltrate into the chromatographic system. Thiopurine nucleotide concentrations were calculated by subtracting the thiopurine nucleoside concentrations measured after treatment with acid phosphatase from those measured after direct injection of ultrafiltrate in the chromatographic system. Analytes were separated on a C18 Supelco column with ammonium phosphate-methanol eluent coupled with ultraviolet detection. RESULTS: CVs for intra- and interday precision were 1.1-14% (median, 4.9%), and recovery of added analyte was 89-126% (median, 105%) at low and high concentrations of analytes, except for mercaptopurine riboside. The median signal for each of the five metabolites in lymphoblast samples was 98% (range, 80-106%) of that in water. Detection limits for thiopurine bases and nucleosides ranged from 0.5 to 4.5 pmol/5 x 10(6) cells. CONCLUSIONS: This method is suitable for measurement of thiopurine metabolite concentrations in lymphoblasts in children with acute lymphoblastic leukemia following a single dose of intravenous mercaptopurine.