Novel Strategy to Drive the Intracellular Uptake of Lipid Nanoparticles for Photodynamic Therapy

Abstract

Nanoparticles' uptake by cancer cells upon reaching the tumor microenvironment is often the ratelimiting step in cancer nanomedicine. Herein, we report that the inclusion of aminopolycarboxylic acid conjugated lipids, such as EDTA-or DTPA-hexadecylamide lipids in liposome-like porphyrin nanoparticles (PS) enhanced their intracellular uptake by 25-fold, which was attributed to these lipids' ability to fluidize the cell membrane in a detergent-like manner rather than by metal chelation of EDTA or DTPA. EDTA-lipidincorporated-PS (ePS) take advantage of its unique active uptake mechanism to achieve > 95 % photodynamic therapy (PDT) cell killing compared to < 5 % cell killing by PS. In multiple tumor models, ePS demonstrated fast fluorescence-enabled tumor delineation within minutes post-injection and increased PDT potency (100 % survival rate) compared to PS (60 %). This study offers a new nanoparticle cellular uptake strategy to overcome challenges associated with conventional drug delivery.