“…Thus, they could more easily respond to endogenous and exogenous stimuli (e.g., pH, redox, enzymes, light, temperature, magnetic field, ionic concentration, etc. ), , as well as be accompanied by releasing the cargos encapsulated in the nanocarriers. The pH of the normal physiological environment is ∼7.4, while the extracellular environment of tumor cells is weakly acidic (pH ∼6.8), and even the pH of endosomes/lysosomes is more acidic inside tumor cells (pH 4.5–6.5), which provides the possibility to design and construct nanocarriers with specific responses based on endogenous pH differences.…”