Colloidal gold modified with a genetically engineered nitroreductase: toward a novel enzyme delivery system for cancer prodrug therapy.

Directed enzyme prodrug therapy is an extensive area of research in cancer chemotherapy. Although very promising, the current directed approaches are still hampered by inefficient enzyme expression and tumor targeting. This work investigates the viability of using metal nanoparticles as a novel delivery vehicle for prodrug-activating enzymes.

A kinetic analysis of three modified novel nitroreductases.

A kinetic comparison between three nitroreductase enzymes isolated from the genome of Bacillus licheniformis ATCC 14580 for prospective use as immobilised enzymes for explosives detection has been conducted. The genes encoding the three enzymes (yfkO [BLNfnB] encoding an NfsB-like enzyme; nfrA [BLNfrA1] and ycnD [BLNfrA2] encoding PnrA-like enzymes) have been PCR amplified from the native genome and cloned into pET-28a(+) and a modified cysteine((6))-tagged pET-28a(+) and subsequently over-expressed, purified, and biochemically characterised. The previously uncharacterised nitroreductases exhibited activity against a wide range of explosives, including cyclic nitramines.

An in situ amperometric biosensor for the detection of vapours from explosive compounds.

An amperometric biosensor based on genetically-modified enzymes was used for the in situ detection of trace vapours from a number of explosive compounds. The vapour samples that were generated from a purpose-built vapour generator were collected and pre-concentrated using a trap able to concentrate samples at a rate of 60-fold per minute of sampling. The amperometric biosensor achieved a remarkably low vapour detection limit of 6 parts per trillion from a room temperature sample.

Synthesis and photoreactivity of 4,5-dithienyl[1,3]dithiol-2-ones.

Whereas irradiation of 4,5-dithiophen-2-yl[1,3]dithiol-2-one leads to the expected 2,3,5,6-tetrathiophen-2-yl-1,4-dithiine product, similar reaction of thiophen-3-yl-substituted [1,3]dithiol-2-ones leads to thieno[3,4-c]dithiines via a unique ring cleavage reaction.

The influence of water vapour on the determination of glutaraldehyde vapour concentrations using an electrochemical fuel cell sensor.

The effects of relative humidity (40-90% RH) and varying glutaraldehyde vapour concentrations (< 0.1 ppm) on the response of an electrochemical fuel cell sensor have been investigated over time (0-400 s). These studies have identified changes in the response of the fuel cell with time after sampling.

Chemical and structural characterization of exopolymers produced by Pseudomonas sp. NCIMB 2021 in continuous culture.

The growth of marine Pseudomonas sp. NCIMB 2021 as continuous cultures in the presence of surfaces of AISI 316 stainless steel allowed the isolation and partial chemical characterization of exopolymers released into the culture medium (free exopolymers), as well as capsular and biofilm exopolymers. Fourier-transform infrared (FTIR) spectroscopy demonstrated the presence of O- and N-acetylation within the carbohydrate moieties and a predominant 310-helical structure of the protein component, highly resistant to hydrogen/deuterium exchange.

Thiophene-Functionalized TTF pi-Electron Donors as Potential Precursors to Conducting Polymers and Organic Metals: Synthesis, Properties, Structure, and Electropolymerization Studies.

The synthesis and physical properties of a series of novel thiophene-substituted TTF electron donors (6a-d) are described. The cyclic voltammograms of 6a-d exhibited two reversible one-electron redox waves, characteristic of TTF derivatives. Electropolymerization studies on compound 6a in nitrobenzene indicate that no polymer formed on the working electrode, but a blue-colored intermediate was observed diffusing away from the electrode.