The mixtures of polyvinyl alcohol (PVA) and polyethylene glycol (PEG) with calcium chloride (CaCl2) were exposed to gamma-irradiation to synthesize transparent hydrogels for wound dressing. In this system, CaCl2 was used not only as a gelling material but also as a plasticizer. The presence of CaCl2 enhances the effects of PEG, this synergistic effects give births a new hydrogel with improved c...

To further understand the relationships between DNA dam age, DNA repair, and cellular end points such as survival and mutation, the repair capacity of a DNA repair-deficient mutant (strain UV-20) of Chinese hamster ovary cells was character ized in response to DNA cross-linking agents. This mutant, previously shown to be hypersensitive to killing by both ultra violet light and the cross-linking...

To further understand the relationships between DNA damage, DNA repair, and cellular end points such as survival and mutation, the repair capacity of a DNA repair-deficient mutant (strain UV-20) of Chinese hamster ovary cells was characterized in response to DNA cross-linking agents. This mutant, previously shown to be hypersensitive to killing by both ultraviolet light and the cross-linking ag...

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Intermolecular thiol cross-linking was used to determine surface-exposed positions in 250 lactose permease mutants containing single-Cys replacements in each transmembrane helix. Significant cross-linking of monomers to produce homodimers is observed in nine mutants with a 5-A-long cross-linking agent containing bis-methane thiosulfonate reactive groups [position 78 (helix III); positions 185, ...

DNA interstrand cross-linking had been found previously to correlate with differences in sensitivity among human cell strains treated with chloroethylnitrosoureas. These differences had been attributed to the presence or absence of a specific DNA repair mechanism. The current work addressed the question of whether another DNA cross-linking agent, cis-diamminedichloroplatinum(II) (cis-Pt), would...

A kinetic gelation model has been developed that incorporates the kinetics of a living/ controlled radical polymerization. Specifically, the kinetics of an iniferter polymerization were implemented in the model to determine the effect of the kinetics on the polymer structure. In particular, the replacement of the termination step with a reversible termination was examined. The model predicts th...

PURPOSE Microparticles of diameter < 5 microm were synthesized by interfacial cross-linking of 7.5% (w/v) beta-cyclodextrins (beta-CD) with 4.5% (w/v) terephtaloyle chloride in 1 M NaOH, in order to provide stable vector for drug encapsulation suitable for administration at the alveolar scale. METHODS Batches were prepared varying different parameters such as amount of monomer (beta-CD) (5-30...

Overexpression of the trans-membrane drug efflux pump P-glycoprotein is one of the major mechanisms by which cancer cells develop multidrug resistance. We demonstrated previously that noncytotoxic doses of various genotoxic chemicals, particularly DNA cross-linking agents, preferentially altered expression of inducible genes. These effects occurred principally at the transcriptional level and w...