Differential anticancer drug delivery with a nanogel sensitive to bacteria-accumulated tumor artificial environment.

Differential anticancer drug delivery that selectively releases a drug within a tumor represents an ideal cancer therapy strategy. Herein, we report differential drug delivery to the tumor through the fabrication of a special bacteria-accumulated tumor environment that responds to bacteria-sensitive triple-layered nanogel (TLN). We demonstrate that the attenuated bacteria SBY1 selectively accumulated in tumors and were rapidly cleared from normal tissues after intravenous administration, leading to a unique bacteria-accumulated tumor environment. Subsequent administrated doxorubicin-loaded TLN (TLND) was thus selectively degraded in the bacteria-accumulated tumor environment after its accumulation in tumors, triggering differential doxorubicin release and selectively killing tumor cells. This concept can be extended and improved by using other factors secreted by bacteria or materials to fabricate a unique tumor environment for differential drug delivery, showing potential applications in drug delivery.