Ligand-decorated nanogels: fast one-pot synthesis and cellular targeting.

Nanoscale vehicles for delivery have been of interest and extensively studied for two decades. However, the encapsulation stability of hydrophobic drug molecules in delivery vehicles and selective targeting these vehicles into disease cells are potential hurdles for efficient delivery systems. Here we demonstrate a simple and fast synthetic protocol of nanogels that shows high encapsulation stabilities. These nanogels can also be modified with various targeting ligands for active targeting. We show that the targeting nanogels (T-NGs), which are prepared within 2 h by a one-pot synthesis, exhibit very narrow size distributions and have the versatility of surface modification with cysteine-modified ligands including folic acid, cyclic arginine-glycine-aspartic acid (cRGD) peptide, and cell-penetrating peptide. T-NGs hold their payloads, undergo facilitated cell internalization by receptor-mediated uptake, and release their drug content inside cells due to the reducing intracellular environment. Selective cytotoxicity to cells, which have complementary receptors, is also demonstrated.