Cell Carriers for Oncolytic Virus Delivery: Prospects for Systemic Administration

Treatment of the malignant diseases using oncolytic viruses (OVs) is currently considered as a promising therapeutic approach. Initial encouraging results fueled a large number of clinical trials, showcasing favorable safety profiles of OVs - but therapeutic outcomes remain far from perfect. Efficacy of systemically administered OVs is limited due to poor bioavailability, rapid immune clearance, and suboptimal biodistribution. Cell-based carriers that can shield viral particles and provide tumor-targeted OV delivery, represent one of the potential ways to address these challenges. Feasibility of this approach was demonstrated using a broad range of cell types, including mesenchymal stem cells (MSCs), neural stem cells (NSCs), different subsets of immune cells and cancer cell lines. The resulting spectrum of carriers can be viewed as a multifaceted tool, taking into account the specific properties, advantages, and limitations of each cell carrier type discussed in this review. Careful consideration of these features will provide the basis for successful development of cell-based OV delivery platforms.