Synergistic VSV Virotherapy and Carbon Nanotube Photothermal Therapy for Osteosarcoma in Murine Models

Wide resection is usually performed for malignant bone and soft tissue tumors, but there is often functional impairment of the affected limb. In this study, we performed virotherapy with the vesicular stomatitis virus (VSV) and photothermal therapy using carbon nanotubes (CNTs) in combination for osteosarcoma, followed by marginal excision. The possibility of local treatment of the primary tumor was then assessed.

LM-8 cells (1×10⁷) were subcutaneously implanted into 5-week-old mice to generate an in vivo osteosarcoma mouse model. Marginectomy was performed. Four groups with six mice each were created: VSV+SWCNTs group, VSV group, SWCNTs group, and an untreated group. Tumor margin resection was performed 2 weeks after tumor cell transplantation. The primary tumor volume, local recurrence, distant metastasis, and survival rate were evaluated.

The combination of VSV virotherapy and CNTs photothermal therapy resulted in shrinkage of the primary tumor and reduced local recurrence after marginectomy. There was no significant difference in distant metastasis or survival rate for all groups.

Combining virotherapy with VSV and CNTs photothermal therapy is useful for local treatment of osteosarcoma in murine models, possibly allowing for smaller tumor resection margins.