Fabrication of chitosan functionalized dual stimuli-responsive injectable nanogel to control delivery of doxorubicin

Stimuli-responsive hydrogel could respond rapidly to environmental changes, whereas the limitation of gel scale usually led to a single route of drug delivery and restricted application. Herein, a pH and temperature dual responsive nanogel CS/P(MAA-co-NIPAM) was successfully prepared by radical polymerization. The change of both turbidity and hydration diameter at different conditions indicated that the nanogel possessed obvious pH and temperature sensitive properties. Specifically, the hydration diameters of the nanogel were 234 nm at T = 20 °C and 145 nm at T = 45 °C. The schematic flowable characteristic by injection experiment indicated that CS/P(MAA-co-NIPAM) might have the potential application possibility of injectable drug delivery. In addition, with doxorubicin as the model drug, the drug loading efficiency of the nanogel was 84.00% and the maximum release efficiency reached 66.30% at pH = 2.0 & T = 20 °C. The nanogel was able to realize drug delivery process in physiological environment according to in-vitro controlled releasing experiments.