CIVO Tumor Microinjection Platform
The CIVO tumor microinjection platform: (A) The CIVO platform consists of a handheld array of up to eight needles capable of simultaneously penetrating subcutaneous tumors and delivering microdoses of candidate therapeutics. (B) For preclinical studies, tumors were grown as flank xenografts in immunocompromised mice and injected while mice were anesthetized. A chemically inert ITD was co-injected through each needle. (C) A representative example of the ITD signal from a tumor injected using a five-needle array visualized with a Xenogen In Vivo Imaging System (IVIS). (D) A longitudinal IVIS scan demonstrating the column-like distribution of the tracking dye signal from a single needle spanning the z axis of the tumor. (E) Tumor responses were assessed after resection of the tumor via histological staining of cross sections (4 μm thick) sampled at 2-mm intervals perpendicular to the injection column. (F) High-resolution whole-slide scanning captured images of every cell from each 4-μm-thick tissue section. (G) A representative tumor response to microinjected drug at a single injection site. Nuclei, DAPI (4′,6-diamidino-2-phenylindole) (blue); ITD (green); a drug-specific biomarker (orange). (H) The resulting images were processed by a custom image analysis platform called CIVO Analyzer, which classifies the cells within each region of interest as biomarker-positive (green dots) or biomarker-negative (red dots).