Intranasal Delivery of Therapeutic Neural Stem Cells (NSCs) in Murine Model: A Procedure for Tumor-targeted Delivery of Oncolytic Virus Loaded NSCs into Brain Tumor Bearing Mouse Model

To begin, subject a culture of neural stem cells or NSCs to low oxygen conditions. This preconditioning facilitates enhanced NSC proliferation and tumor-targeting abilities. Next, harvest the NSCs and treat with the desired concentration of conditionally replicating oncolytic virus. Incubate to load the viruses into the cells.

Now, centrifuge the culture to remove unbound viruses. Resuspend the virus-loaded NSCs in a suitable buffer.  Meanwhile, position an anesthetized brain tumor-bearing mouse in the supine position for easier access to nostrils. Carefully administer the virus-loaded NSCs into each nostril of the mouse, repeating at short-time intervals.

Allow the mouse to recover. The intranasally administered NSCs in the nasal cavity bypass the blood-brain barrier to enter the brain. Inside the brain, the virus replicates within these preconditioned cells and migrates to the tumor site, protecting itself from the immune system. Over time, the viral particles released from the NSCs interact and bind to specific cell surface receptors overexpressed on tumor cells.

Following virus internalization, these conditionally replicating viruses preferentially replicate in the tumor cells and cause cell lysis. The lysed tumor cells release viral particles, which infect the surrounding tumor cells, leading to a cascade of infection and tumor cell lysis. The cell lysis exposes the tumor antigens, activating an immune response against tumor cells.