Synthesis and characterization of sulfoxide-functional polyethers in low temperature aqueous environments

Polymeric materials provide a low-toxicity, low osmolality, and high functionality alternative to small molecule colligative antifreeze agents such as solutions of dimethylsulfoxide (DMSO) or glycerol. Polymers can be designed that are inherently non-toxic and produce high post-thaw recovery of mammalian cells after frozen storage at –196 ºC. In this presentation, I will describe our efforts in the design and synthesis of improved cryoprotective polymeric materials and how design has been guided by investigation of polymer-water-ice-cellular interactions, and also post-thaw viability assays of model cell lines. Significantly, materials have been synthesized that increase the extent of the unfrozen fraction of aqueous solutions upon cooling, increase solution glass-transition temperature, and that also affect the kinetics of cellular dehydration during freezing; these factors are believed to be important in affecting polymer-mediated post-thaw recovery of mammalian cells. However, many fundamental questions remain.