Efficacy of Photothermal Ablation Using Intravenously Delivered NIR-Absorbing Nanorods in Colon Cancer
G. Goodrich, D. Payne, K. Sharp, L. Bao, K. Sang
Nanospectra Biosciences, Inc., US
Keywords: nanorod, thermal ablation, cancer
Abstract:Here we investigate the photothermal ablation of colon cancer in an animal model using intravenously delivered gold nanorods. Nanorods with an aspect ratio of ~3.2 and an extinction peak of 774 nm were PEGylated, suspended in an isotonic solution, and infused into the tail vein of BALB/c mice bearing subcutaneous CT26.wt murine colon cancer tumors. The nanoparticle dose (~20 OD) and accumulation time (24 hrs) were chosen based on prior dosing and circulating half-life. After 24 hrs, an isotropic laser fiber was inserted through a small incision in the skin to a point proximate to and beneath the tumor. The area was illuminated with 3.5 W average power for 3 minutes. Control groups consisted of laser-only, nanorod-only and untreated tumored animals. The survival of the animals receiving nanorod-based photothermal ablation was statistically longer than the control groups with >50% complete response (Figure 1). This work demonstrates the promise of systemically delivering nanoparticles to tumors for thermal ablation.