Template-free synthesis of biodegradable nanogels with tunable sizes as potential carriers for drug delivery

Biodegradable nanogels with tunable sizes, synthesized by a template-free method, as potential carriers for drug delivery are reported. The nanogels are obtained by crosslinking thermo-induced nanoparticles, with subsequent swelling at low temperatures, which were based on a thermosensitive and biocompatible triblock copolymer composed of poly(ethylene glycol) and poly(ethyl ethylene phosphate). The nanogels loaded with doxorubicin are efficiently taken up by A549 tumor cells and the drug could be released intracellularly, demonstrated by flow cytometric analyses and confocal laser scanning microscope observations. It results in enhanced growth inhibition activity to tumor cells in comparison with free doxorubicin treatment. These polyphosphoester and poly(ethylene glycol) based nanogels are biocompatible and biodegradable, rendering potential for drug delivery applications.