document: CED procedures. The details of the CED procedure are as described in our previous study. Briefly, infusion cannulas were fabricated with silica tubing (Polymicro Technologies, Phoenix, AZ, USA) fused to a 0.1 mL syringe (Plastic One, Roanoke, VA, USA) with a 0.5 mm stepped-tip needle that protruded from the silica guide base. The treatment agents (VLPs or drugs) were loaded into the syringes and attached to a microinfusion pump (Bioanalytical Systems, Lafayette, IN, USA). The syringe with a