Ultrasound targeted VS1-loaded microbubbles for oncolytic virotherapy of breast cancer

Oncolytic viruses (OVs) are genetically modified or naturally occurring viruses that target and eliminate tumor cells. OVs have tremendous potential due to their dual attack mechanism that involves direct tumor cell lysis and potentiation of an anticancer immune response. The reticuloendothelial system's clearance after systemic delivery is one of the major issues with many OVs. To tackle this problem, in this paper, a micro-bubble formulation incorporating a virus sensitizer (VS1), a small molecule that acts as a viral sensitizer is presented: it consists of a lipid microbubble loaded with VS1 which can enhance OV replication in tumor cells, the release of VS1 is facilitated by ultrasound, and it is expected to potentially allow i.v. administration of OV therapy.