Endogenous stimuli-responsive nanoparticles for cancer therapy: From bench to bedside.

Cancer is complicated to treat because of its high propensity for recurrence and metastasis, and various side effects of conventional cancer treatments. With the development of nanotechnology, biology, material science and pharmacy, nanoparticles emerge as a promising method to load anti-cancer drugs to deal with the downsides of conventional treatments. Among the various class of nanoparticles, endogenous stimuli-responsive nanoparticles exert significant anti-cancer effects by releasing drugs due to the stimulations from pH gradient, redox as well as other enzymes of cancer microenvironment. Extraordinary progress has been achieved as the latest endogenous stimuli-responsive nanoparticles exhibit better therapeutic effects, lower toxicity, and superior biocompatibility, indicating brighter prospects for cancer therapy. However, these stimuli-responsive nanoparticles are still not ready for large-scale clinical application, due to reasons such as the lack of clinical trials and high cost of manufacturing. Here, we consolidate the advancements and limitations of various endogenous stimuli-responsive nanoparticles, as well as critically discuss the prospects of this kind of nanoparticles in tumor treatments.