Detection of brain tumors using fluorescence diffuse optical tomography and nanoparticles as contrast agents.

Near-infrared fluorescence-enhanced diffuse optical tomography (fDOT) is used to localize tumors in mice using fluorescent nanoparticles as a blood pool contrast agent. The infrared dye DiR is loaded in the lipid core of nontargeted nanoparticles (DiR-lipidots) and injected systemically via the tail vein in mice bearing U87 tumors. Distribution and time-course of DiR-lipidots are followed using in vivo fluorescence reflectance imaging and reveal enhanced fluorescent signal within the subcutaneous tumors up to seven days due to the enhanced permeability and retention effect.

Tumor targeting of functionalized lipid nanoparticles: assessment by in vivo fluorescence imaging.

Lipid nanoparticles (LNP) coated by a poly(oxyethylene) polymer have been manufactured from low cost and human use-approved materials, by an easy, robust, and up-scalable process. The incorporation in the formulation of maleimide-grafted surfactants allows the functionalization of the lipid cargos by targeting ligands such as the cRGD peptide binding to alpha(v)beta(3) integrin, a well-known angiogenesis biomarker. LNP are able to encapsulate efficiently lipophilic molecules such as a fluorescent dye, allowing their in vivo tracking using fluorescence imaging.