Environmental Stability of Vesicle-Cloaked Virus Clusters and Health Implications

Human viruses cause serious diseases worldwide. Growing evidence shows that viruses do not exist as single viral particles but as viral vesicles, which are clusters of viral particles surrounded by lipid membrane. The membrane protects the internal viruses from environmental stress and disinfectants. As a result, viral vesicles can survive in water and other environments, potentially increasing their ability to infect people. Despite their public health importance, little is known about why viral vesicles are so stable. It is also unclear how vesicles’ physical properties influence their transmission and infection. This project will use experiments and modeling to investigate the mechanical properties of viral vesicles. It will then examine how these properties influence vesicles’ survival in the environment. By clarifying the mechanism, the project results will improve the design of engineering interventions to control viral transmission. The project will also train students in hands-on scientific research, thereby strengthening the future workforce in engineering and biotechnology. The project will elucidate the viscoelastic properties, environmental stability, and infectivity of viral vesicles using an integrated framework that combines scanning probe microscopy, theoretical mechanics, environmental chemistry, and virology. Viral vesicles will be harvested from cell culture, human stool, and wastewater, and their size distributions and lipid compositions will be quantified. Synthetic liposomes will then be fabricated to match measured vesicle dimensions and membrane compositions, serving as surrogates and mechanical benchmarks to isolate the structural and compositional determinants of vesicle behavior. Atomic force microscopy-based nanoindentation and force spectroscopy will be employed to obtain force-deformation curves, which will be analyzed using the Generalized Maxwell viscoelastic model to extract storage and loss moduli as functions of deformation timescale under environmentally relevant aqueous conditions, including exposure to detergents. The resulting framework will advance fundamental understanding of how mechanical properties govern viral vesicle stability and infectivity and provides predictive insight for engineering-based control strategies. 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.