CAREER: Identification and characterization of low toxicity cryoprotective solutions

About This Grant

Cooling has been used as a means of preservation for centuries. The ability to achieve very low temperatures has led to the storage of cells, tissues, and organs in a process called cryopreservation. Extremely low temperatures can rupture cells due to ice crystal formation inside the cell. Cryoprotective agents (CPAs) are chemical mixtures that suppress ice crystal formation. Unfortunately, many CPAs currently used are also toxic to cells. The goal of this project is to identify and design new CPAs that exhibit reduced toxicity. Disseminating educational videos and performing K-12 outreach will increase awareness and understanding of cryopreservation. Recruiting community college students to participate in laboratory research will expand the science and engineering workforce. CPA toxicity is the major limitation of cryopreservation technologies. This is especially true for vitrification. This is an ‘ice-free’ approach. High concentrations of CPAs are loaded into biospecimens followed by rapid cooling through the glass transition temperature. This causes amorphous solidification of water (i.e. glass formation). Vitrification is especially useful for multicellular systems where avoidance of ice preserves the tissue architecture. A major barrier to the development of vitrification protocols is CPA toxicity. Despite a vast chemical space of glass forming molecules, the field typically relies on a very small subset of fewer than10 penetrating CPAs. The central hypothesis of this proposal is that examination of a larger chemical space will yield new CPAs with reduced toxicity and ideal physicochemical properties for vitrification. High-throughput screening (HTS) assays will be used to examine a range of glass-forming molecules. The CPAs will be further examined as multicomponent cocktails to discover formulations that exhibit minimal toxicity. A range of chemical and biological assays will help identify the mechanisms driving CPA toxicity. Finally, small molecules will target pathways responsible for CPA damage as an approach to reverse or eliminate toxicity. This project is expected to lead to the development of minimal toxicity vitrification solutions, which are critically needed in the field of cryobiology. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.