Radiolysis and photolysis studies on active transient species of berberine.

In this paper, the photochemical and photobiological characters of the active radicals of berberine (BBR) was investigated for finding an efficient and safe photosensitizer with highly active transient products using in Photodynamic therapy (PDT) study. The active species of BBR was generated and identified by using pulse radiolysis method. In neutral aqueous solution, BBR react with hydrated electron and hydroxyl radical, forming the radical anion and neutral radical of BBR, and the related reaction rates were determined as 3.

Interaction mechanism between berberine and the enzyme lysozyme.

In the present paper, the interaction between model protein lysozyme (Lys) and antitumorigenic berberine (BBR) was investigated by spectroscopic methods, for finding an efficient and safe photosensitizer with highly active transient products using in photodynamic therapy study. The fluorescence data shows that the binding of BBR could change the environment of the tryptophan (Trp) residues of Lys, and form a new complex. Static quenching is the main fluorescence quenching mechanism between Lys and BBR, and there is one binding site in Lys for BBR and the type of binding force between them was determined to be hydrophobic interaction.

Characterization of the transient species generated by the photoionization of Berberine: a laser flash photolysis study.

Using 266 nm laser flash photolysis it has been demonstrated that Berberine (BBR) in aqueous solution is ionized via a mono-photonic process giving a hydrated electron, anion radical that formed by hydrated electron react with steady state of BBR, and neutral radical that formed from rapid deprotonation of the radical cation of BBR. The quantum yield of photoionization is determined to be 0.03 at room temperature with KI solution used as a reference.

Nanotoxicity of TiO(2) nanoparticles to erythrocyte in vitro.

Titanium dioxide (TiO(2)) has been considered as non-toxic mineral particles widely used in the fields like cosmetics, food and drug. When the scale come to nanometer, TiO(2) nanoparticles (nano-TiO(2)) exhibits multiple specific characteristics coupled with unknown risks on health. The purpose of this study was to systematically research the influence of nano-TiO(2) on erythrocyte.

[Laser photolysis study on photochemical reactions in mixed solutions of [bmim][PF6] and acetonitrile].

Laser flash photolysis study was carried out for the first time in the binary mixture of room-temperature ionic liquid (RTIL) and traditional organic solvent. Photochemical properties of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] and its binary mixed solutions with MeCN were investigated by laser photolysis technique at an excitation wavelength of 355 nm, using anthraquinone (AQ) as a probe molecule. It was indicated that [bmim] [PF6] itself participates in the reaction with 3AQ*.

[Synthesis and screening of polyethylenimine as a carrier for gene transfer into cultured human tumor cells].

Background & Objective: Choosing suitable gene carrier is very important in gene therapy. Recently, polyethylenimine (PEI), a new polycation compound, is particularly attractive due to its high transduction efficiency and low toxicity. This study was to synthesize a series of PEI nanogels of different particle diameters by photochemistry, investigate the relation between the transfection efficiency and particle diameter, and screen ideal gene carrier.

Size-dependent properties of M-PEIs nanogels for gene delivery in cancer cells.

Polyethyleneimine nanogels (named as M-PEIs) with different sizes were prepared by photo-Fenton reaction in aqueous solution from which samples of 38, 75, 87, 121, 132 and 167nm were selected for in vitro transfection. The homogeneous structure and the same component made it possible to study the size effect of M-PEIs nanogels on gene transfection efficiency when loading the same quantity of plasmid DNA (pLEGFP-C1) into A549, Bel7402, BGC-823 and Hela cells. M-PEIs and its DNA complexes were characterized by photo correlation spectroscopy and atomic force microscopy.

[Spectral analysis of transient species of quinoline degradation].

Quinoline's degradation was studied by pulse radiolysis. It was found that hydrated electron, hydrogen radical, hydroxyl radical and SO4*- can react with quinoline. The absorption spectra of the transient species of quinoline were obtained, and related constants were determined, but it was found that the species of Br2*- and N3*- can't react with quinoline.

Supramolecular interaction between water-soluble calix[4]arene and ATP--the catalysis of calix[4]arene for hydrolysis of ATP.

The catalysis effect of water-soluble calix[4]arene C[4] (calix[4]arene-5,11,17,23-tetrasulfonate) on hydrolysis of ATP in aqueous solution was studied by HPLC. Using laser photolysis and pulse radiolysis, the supramolecular interaction between water-soluble calix[4]arene and ATP was investigated.