(219b) Virus Encapsulation in Polypeptide Complex Coacervates for Vaccine Formulations

The lack of shelf stability of biological therapeutics can cause large disruptions in distribution of life saving medicines. We have been exploring the ability of polypeptide complex coacervates to stabilize viral vaccine models at higher temperatures. This would increase the equitable distribution of vaccines worldwide. Charge patterning of peptide coacervates and the charge patterning on the virus surface highly influence encapsulation and thermal stability of virus. Here we show that porcine parvovirus (PPV), which is highly charged, has a high encapsulation efficiency and it can be influenced by peptide charge density during coacervation. However, human rhinovirus 14 (HRV) has a lower charge on its surface and encapsulation into the coacervate phase is halted when charge patterning is introduced. Coacervate stability can be altered by changes in the cationic polymer and hydrophobicity of the polymer. The general encapsulation trends are different for viruses than for proteins. This demonstrates the need to continue to explore methods to stabilize viral vaccine formulations and polypeptide complex coacervates may hold important keys to understanding the stability of future viral vaccine formulations.