Mitchell Winnik

Current research in the Winnik group centers on three seemingly unrelated projects. Our work on crystallization-driven self-assembly (CDSA) of block copolymers has led to interest in biomedical applications of rod-like nanoparticles (NPs). We study how NP surface chemistry influences cell uptake and penetration into multicellular tumor spheroids, a model for avascular tumor regions.

The second project focuses on developing new reagents for mass cytometry (MC), a high-throughput technique for measuring biomarkers on individual cells using antibodies labeled with heavy metal isotopes and atomic mass spectrometry detection. We synthesize metal-chelating polymers and metal-containing NPs, attach antibodies, and evaluate their performance. Although current MC technology measures up to 50 parameters per cell at 500 cells per second, its potential exceeds 120. Progress is limited by the lack of reagents capable of binding isotopes of soft heavy metal ions, for which each element requires a specific chelator. This work is conducted in close collaboration with Standard BioTools in Markham, ON.

Our third research area involves a long-standing collaboration with the coatings industry to provide a knowledge base to support the development of environmentally compliant paints and coatings. Using emulsion polymerization, we synthesize polymer NPs, often with complex internal structures, label domains with fluorescent dyes, and apply fluorescence resonance [FRET] energy transfer techniques to study phase miscibility and polymer diffusion in films. We currently work closely with BASF on their innovative technologies. Common to all projects are polymer and NP synthesis, colloid science, and analytical and spectroscopic characterization.

Our team-based approach brings together students with diverse backgrounds and provides strong opportunities for industry collaboration.