Anti-Ice Aptamers for Improved Red Blood Cell Storage

OmniSite BioDiagnostics (OmniSite) proposes to continue development of DNAaptamers to early ice crystal nuclei by Systematic Evolution of Ligands byEXponential enrichment (SELEX), which will be used to prevent damage tohuman red blood cells (RBCs) during lyophilization, thereby increasing the shelflife of blood intended for military casaulties. In Phase I, OmniSite demonstratedthat rare DNA aptamers from a diverse random library were capable ofbinding to a molecular mimic of an early ice crystal structure that wasimmobilized on an affinity column. These apatmers were recovered andamplified by PCR. In Phase II, OmniSite proposes to prove the efficacy ofthese aptamers as anti-freeze protective agents for erythrocytes throughtesting in conjunction with the Walter Reed Army Institute of Research(WRAIR). In addition, OmniSite will clone and sequence the anti-ice aptamers. Whenconsensus DNA sequences are obtained, OmniSite will have these sequencessynthesized and verify that such sequences are effective at preventing icedamage to RBCs. OmniSite will also conduct computer-aided molecular modeling(energy minimization) studies to determine the probable secondary andpossible tertiary structures of the anti-ice apatmer consensus sequences.Finally, OmniSite will investigate the buffer composition, ionic strength,delivery amount per unit volume of blood and other aspects associated wihpackaging of the anti-ice aptamers for use by the Army.