Liposomes-Camouflaged Redox-Responsive Nanogels to Resolve the Dilemma between Extracellular Stability and Intracellular Drug Release.

Liposomes have shown great promises for pharmaceutical applications, but still suffer from the poor storage stability, undesirable drug leakage, and uncontrolled drug release. Herein, liposomes-camouflaged redox-responsive nanogels platform (denoted as "R-lipogels") is prepared to integrate the desirable features of sensitive nanogels into liposomes to circumvent their intrinsic issues. The results indicate that drug-loaded R-lipogels with controlled size and high stability not only can achieve a very high doxorubicin (DOX)-loading capacity (12.9%) and encapsulation efficiency (97.3%) by ammonium sulfate gradient method and very low premature leakage at physiological condition, but also can quickly release DOX in the reducing microenvironment of tumor cells, resulting in effective growth inhibition of tumor cells. In summary, the strategy given here provides a facile approach to develop liposomes-nanogels hybrid system with combined beneficial features of stealthy liposomes and responsive nanogels, which potentially resolves the dilemma between systemic stability and intracellular rapid drug release.