Synthesis of a Glucuronic Acid-Containing Thioglycoside Trisaccharide Building Block and Its Use in the Assembly of Cryptococcus Neoformans Capsular Polysaccharide Fragments.

As part of an ongoing project aimed at identifying protective capsular polysaccharide epitopes for the development of vaccine candidates against the fungal pathogen Cryptococcus neoformans, the synthesis and glycosylation properties of a naphthalenylmethyl (NAP) orthogonally protected trisaccharide thioglycoside, a common building block for construction of serotype B and C capsular polysaccharide structures, were investigated. Ethyl (benzyl 2,3,4-tri-O-benzyl-β-d-glucopyranosyl- uronate)-(1→2)-[2,3,4-tri-O-benzyl-β-d-xylopyranosyl-(1→4)]-6-O-benzyl-3-O-(2-naphthalenylmethyl)-1-thio-α-d-mannopyranoside was prepared and used both as a donor and an acceptor in glycosylation reactions to obtain spacer equipped hexa- and heptasaccharide structures suitable either for continued elongation or for deprotection and printing onto a glycan array or conjugation to a carrier protein. The glycosylation reactions proceeded with high yields and α-selectivity, proving the viability of the building block approach also for construction of 4-O-xylosyl-containing C.

Trajectory-based co-localization measures for nanoparticle-cell interaction studies.

High-resolution live cell microscopy will soon have a fundamental role in understanding bio-nano interactions, providing material that can be exploited using single particle tracking techniques. The present work uses 3D timelapse images obtained with confocal microscopy, to temporally resolve the co-localization between polystyrene nanoparticles and lysosomes in live cells through object-based measurements.

Analysis of phase diagram and microstructural transitions in an ethyl oleate/water/Tween 80/Span 20 microemulsion system using high-resolution ultrasonic spectroscopy.

High-resolution ultrasonic spectroscopy was applied to analyse a pseudo-ternary phase diagram for a mixture consisting of water/ethyl oleate/Tween 80 and Span 20 at 25 degrees C. The measured changes in the ultrasonic velocity and attenuation with concentration of water in oil/surfactants mixtures showed several, well defined stages and transitions between them, which allowed construction of an 'ultrasonic' phase diagram. Quantitative analysis of the ultrasonic parameters enabled characterisation of various phases (microemulsion, liquid crystals and pseudo-bicontinuous) as well as evaluation of the state of the water and particle size in microemulsion phase.