Applications of click chemistry in drug discovery, bioconjugation and material science

Abstract

Click chemistry is a chemical philosophy introduced by Sharpless in 2001 and describes chemistry tailored to generate substances quickly and reliably by joining small units together. This dissertation has focused on the applications of click chemistry in three most relevant categories including drug discovery, bioconjugation, and materials science. The first application is developing new anti-influenza drugs by using click chemistry. We designed the novel anti-influenza reagents based on the Altermune method, which would stimulate the immune system to attack influenza viruses using a Linker Molecule(LM), which can recognize the viruses and also be recognized by immune system. The LM then redirects the immune response to the influenza viruses. The second application is developing a new bioconjugation strategy basing on the “click philosophy”. We developed a new click reagent, 4-dibenzocyclooctynol, which reacts exceptionally fast with azido compounds to give stable triazoles in the absence of any catalyst. A biotin-modified derivative is ideally suited for visualizing and tracking glycoconjugates of living cells that are metabolically labeled with azido-containing monosaccharides. In addition, we also developed a novel quantitative isotopic and chemoenzymatic tagging (QUIC-Tag) containing 4-dibenzocyclooctynol for monitoring the dynamics sialylation in vivo using quantitative mass spectrometry-based proteomics. Because sialic acid is a terminal glycan residue with a notably increased expression in cancers, this method will help to delineate the molecular basis for aberrant glycosylation in cancer and could ultimately be applied for diagnostic and therapeutic. The third application is preparing new nano-drug delivery sysytems. We tried to develop novel multifunctional micellar nanosystems for targeted drug delivery device. To achieve these goals, we successfully conjugated targeting moieties on the nanoparticle surface by using click chemistry. These freestanding polymer particles with targeting ligands can be used as carriers for drug and imaging agents for biomedical applications.