The Evolution of Tumor-Targeted Drug Delivery: From the EPR Effect to Nanoswimmers.
Therapeutic nanotechnologies have made great progress over the past decade. Skepticism has been replaced by the understanding that precision at the nanoscale allows improved treatment modalities in humans.
“Next-generation drug delivery systems will be capable of autonomously swimming towards the disease site and penetrating deep tissue, independent of blood or lymphatic flow.”
Advanced tumor targeting, in which a majority of the injected dose will reach the disease site and penetrate malignant cells, will require combining passive (i.e., EPR), active (ligands), and proactive (swimmers) modalities in a single nanoscale system. Translating nanotherapeutics into clinically approved drugs is not a simple task. Multifunctional nanotherapeutics pose new challenges to the regulatory bodies by introducing several risk factors simultaneously.