Approaches to high throughput physical organic chemistry

High throughput methods applied in biomaterial development and discovery

The high throughput discovery of new bio materials can be achieved by rapidly screening many different materials synthesised by a combinatorial approach to identify the optimal composition that fulfils a particular biomedical application. Here we review the literature in this area and conclude that for polymers this process is best achieved in a microarray format, which enable thousands of cell-material interactions to be monitored on a single chip. Polymer microarrays can be formed by printing pre-synthesised polymers or by printing monomers onto the chip where on-slide polymerisation is initiated. The surface properties of the material can be analysed and correlated to the biological performance using high throughput surface analysis, including time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) measurements. This approach enables the surface properties responsible for the success of a material to be understood, which in turn provides the foundations of future material design. The high throughput discovery of materials using polymer microarrays has been explored for many cell-based applications including the isolation of specific cells from heterogeneous populations, the attachment and differentiation of stem cells and the controlled transfection of cells. Further development of polymerisation techniques and high throughput biological assays amenable to the polymer microarray format will broaden the combinatorial space and biological phenomenon that polymer microarrays can explore, and increase their efficacy. This will, in turn, facilitate the discovery of optimised polymeric materials for many biomaterial applications.

High-throughput mass spectrometry: the mechanism of sudan azo dye fragmentation by ESI tandem mass spectrometry and extensive deuterium labeling experiments

The investigation of the gas-phase chemistry of azo compounds by mass spectrometry dates back to the introduction of this peculiar research field into the armory of physical organic chemistry tools. The mechanism of the fragmentation of the azo double bond from the protonated precursor is discussed with reference to the behavior of deuterium-labeled reference compounds. The investigated molecules belong to the sudan family and the results can be used for the detection of these potential carcinogenic compounds in different matrices by means of the isotope dilution method.