Abstract
BACKGROUND: This study reports the targeting and real-time optical imaging of brainstem tumors using liposomal nanocarriers. Patients with infiltrating brainstem gliomas (BSG) known as diffuse intrinsic pontine gliomas (DIPGs) have one of the poorest survival rates. Blood brain barrier (BBB) is the main obstacle in the delivery of drugs and contrast agents to DIPGs. OBJECTIVE: Here, we demonstrate the specific delivery of liposomal nanoparticles containing Evans blue (nano-EB) to tumor in a murine model of BSG. METHODS/DESIGN: Mice with brainstem tumors were tail vein injected with nano-EB and in vivo tumor enhancement was monitored by optical fluorescence imaging. RESULTS/DISCUSSION: Necropsy analysis conducted 24 hr post injection showed site-specific delivery of nano-EB to the tumor but not adjacent normal tissue. Immunohistochemical assays confirmed high grade tumor at the site of nano-EB accumulation. These findings demonstrate the feasibility of nano-EB for drug delivery and real-time, sensitive optical imaging of BSGs in vivo. The study shows the specific accumulation of liposomal nano-EB nanocarriers in brainstem tumors in our murine model of brainstem glioma. Liposomes are an ideal drug delivery vehicle able to cross the BBB . Specific accumulation of nano-EB in tumor cells is explained by the enhanced permeability and retention (EPR) property of cancer cells which is believed to be due to the abnormal neovasculature with poorly-aligned defective endothelial cells and structure. This pilot study shows the efficacy of liposomes for targeted delivery and possibility of using nano-EB for in vivo imaging of tumors in a murine model of brain tumors.