University of Utah researchers have created a vector system in which capsids from non-enveloped viruses are modified to produce quasi-enveloped viruses. The system is engineered to direct self-release within the vesicle and contains three modular activities: (1) membrane binding, (2) self-assembly, and (3) ability to recruit ESCRT machinery to catalyze membrane fission for release from the cell. Vesicles with internal capsids do not display any antigenic viral properties and are inaccessible to neutralizing antibodies. Specific receptor ligands can be included for cell-specific targeting. Additionally, different genetic elements could be split among multiple capsids, increasing the overall drug payload and overcoming size limitations of enveloped viruses.