High-Pressure Delivery of Oncolytic Viruses via Needle-Free Injection Preserves Therapeutic Activity

Simple Summary We explored the use of needle-free injection (NFI) technology to deliver oncolytic viruses (OVs) for treating solid tumours. The study assesses the infectivity of OVs following NFI and compares the effectiveness of intratumoural administration of Vesicular Stomatitis Virus (VSV) to that of traditional needle injection (NI) in subcutaneous tumours in mice. NFI improves viral tissue distribution and preserves therapeutic activity of this virotherapy. The study establishes NFI as an efficient delivery method for OVs and underscores the need for further optimization to enhance therapeutic efficacy.Abstract Intratumoural delivery of oncolytic viruses (OVs) to solid tumours is currently performed via multiple percutaneous methods of needle injections (NI). In this study, we investigated the potential use of a novel delivery approach, needle-free injection (NFI), to administer OVs to subcutaneous tumours. The stability and genetic integrity of several RNA and DNA viruses exposed to high-pressure jet injectors were first evaluated in vitro. We demonstrate that replication competence and infectivity of the viruses remained unchanged after NFI, as compared to traditional NI. Using the oncolytic Vesicular Stomatitis Virus expressing luciferase (VSV Delta 51-Luc) in the syngeneic CT26 subcutaneous tumour model, we show that NFI administration not only successfully delivers infectious particles but also increases the dissemination of the virus within the tumour tissues when compared to NI. Furthermore, mice treated with VSV Delta 51-Luc by NFI delivery showed similar reduction in tumour growth and survival compared to those with needle-administered virus. These results indicate that NFI represents a novel approach to administer and potentially increase the spread of OVs within accessible solid tumours, highlighting its usefulness in virotherapy.