No abstract

These results demonstrate that the BBN conjugation to NAHis-GC nanoparticles improves their tumor accumulation in PC3-bearing mice in comparison to nanoparticles without BBN, suggesting that BC-NAHis-GC nanoparticles may be useful for prostate cancer imaging.

Oleic acid-conjugated chitosan (oleyl-chitosan) is a powerful platform for encapsulating oleic acid-decorated iron oxide nanoparticles (ION), resulting in a good magnetic resonance imaging (MRI) probe. Oleyl-chitosan could self-assemble into core-shell structures in aqueous solution and provide the effective core compartment for loading ION. ION-loaded oleyl-chitosan nanoparticles showed good enhanced MRI sensitivity in a MR scanner. Cy5.5 dye was accessed to the oleyl-chitosan conjugate for near-infrared (NIR) in vivo optical imaging. After intravenous injection of ION-loaded Cy5.5-conjugated oleyl-chitosan (ION-Cy5.5-oleyl-chitosan) nanoparticles in tumor-bearing mice, both NIRF and MR imaging showed the detectable signal intensity and enhancement in tumor tissues via enhanced permeability and retention (EPR) effect. Tumor accumulation of the nanoparticles was confirmed through ex vivo fluorescence images and Prussian blue staining images in tumor tissues. It is concluded that ION-Cy5.5-oleyl-chitosan nanoparticle is highly an effective imaging probe for detecting tumor in vivo.

We have cloned a laccase gene fragment isolated from a Trametes versicolor strain in Korea. It showed high similarity in nucleotide sequences when compared with other fungal laccases. TNT (2,4,6-trinitrotoluene), a widely used explosive, was transformed rapidly by T. versicolor. When TNT and its catabolic intermediates were added to the fungal culture, they were transformed during the first few hours and the expression level of the laccase gene was increased during the early stage of cultivation.

Syntheses and evaluation of fluoroalkylated ciprofloxacin analogues are described. Among these analogues, N₄'-3-fluoropropylciprofloxacin (16) showed the most efficient antibacterial activity against E. coli strains (DH5α and TOP10) and a high binding affinity for DNA gyrase of bacteria. To develop bacteria-specific infection imaging agents for positron emission tomography (PET), no-carrier-added N₄-3-[¹⁸F]fluoropropylciprofloxacin ([¹⁸F]16) was prepared in two steps from N₄-3-methanesufonyloxypropylciprofloxacin, resulting in a 40% radiochemical yield (decay corrected for 100 min) via the tert-alcohol media radiofluorination protocol with high radiochemical purity (> 99%) as well as high specific activity (149 ± 75 GBq/μmol). The agent was stable (> 90%), as shown by an in vitro human serum stability assay. A bacterial uptake and blocking study of [¹⁸F]16 using authentic compound 16 in TOP10 cells demonstrated its high specific bacterial uptake. The results suggest that this radiotracer holds promise as a useful bacterial infection radiopharmaceutical for PET imaging.