Novel organic-ion-based technology for long-term virus preservation at ambient temperature

PROJECT SUMMERY Most currently available vaccines, especially live and mRNA-based COVID-19 vaccines, are temperature sensi- tive and require stringent cold-chain maintenance, entailing their storage and distribution at recommended tem- peratures from production to administration. This necessity imposes the most prohibitive barrier to global im-

munization programs, particularly in developing countries, accounting for up to 80% of the cost delivery. Thus, there is a critical need for a technology to provide cost-effective and long-term ambient temperature storage for viral samples without requiring cold chain or complicated sample recovery protocols.

This proposal aims to develop an organic-ion platform for long-term storage of viruses at ambient tem- perature to potentially reduce costs in the face of growing needs for new vaccines and avoid labor-intensive maintenance associated with current biobanking technology. Ionic liquids (ILs)  organic salts comprised entirely

of ions  offer a well-suited platform on which the properties can be altered by the selection of ions, enabling the tunable design of solvents/media for virus stabilization. We hypothesize that the solutions of proposed ILs with ca. 20 wt% water may prevent hydrolytic and enzymatic degradation of viral genomes and protein capsids,

providing a reliable approach to preserve viruses. We will use a bacteriophage from the myovirus family as an example of a naked protein particle and dengue virus as an example of a lipid-enveloped particle. First, we will develop a thoughtfully conceived library of novel ILs through systematic variations of heterocyclic cations and

kosmotropic anions, and judicious incorporation of two functionalities (NH3+ and SO2F) into the IL structures. Structural variability will be achieved by pairing new genre of biocompatible cations and anions. Second, we will examine their effectiveness for stabilizing viruses by evaluating their structural integrity, thermostability, and

shelf-life from six months and four year. We will monitor changes in viral secondary structure, thermal denatur- ation, and particle morphology. Last, we will study their empirical structure-activity relationships to gain compre- hensive understanding of binding characteristics and molecular mechanisms of interactions between the viral

particles and the targeted aqueous ionic solvents via simulation, crystallographic, and spectroscopic methods. This project will provide a viable solution for ambient temperature preservation of viruses for extended periods (potentially for decades) by developing the virusILwater matrices that are stable towards hydrolytic

and enzymatic degradation. Another important feature of the proposed approach is that these nucleic acid-ILs solutions can be directly amplified by PCR without being subjected to prior extraction, purification or quantifica- tion. This approach has the merit of simplicity, which makes the process of ambient temperature storage and

distribution profoundly efficient, increases the stability of biosamples for prolonged time, reduces operational costs and carbon footprint, and improves logistics for viruses and virus-based technologies. Summery