1 Department of Chemistry and Biochemistry, Concordia University Montreal Quebec H4B 1R6 Canada john.oh@concordia.ca.
2 Human Health Therapeutics, National Research Council of Canada 6100 Royalmount Avenue Montreal Quebec H4P 2R2 Canada usha.hemraz@nrc-cnrc.gc.ca.

The rise in global food demand and the loss in crop production by pests highlight the need for efficient pesticide delivery systems. Stimuli-responsive degradation with thermoresponsive polymers is a promising platform that offers the controlled release of pesticides. Here, we report the development of millimeter-sized thermoresponsive beads (m-beads) composed of a zwitterionic polysulfobetaine exhibiting upper critical solution temperature (UCST) behavior, crosslinked with biodegradable alginate via supramolecular ionic interactions with calcium ions in water. The fabricated m-beads are capable of encapsulating fluorescein and glufosinate ammonium pesticide with encapsulation efficiency greater than 99%. Promisingly, they exhibit enhanced release with an increasing amount of alginate in m-beads as well as at a temperature above the UCST. This work highlights the potential of UCST-type polysulfobetaine-based m-beads as a smart delivery platform, offering environmentally-triggered release of pesticides.