Stimuli-responsive nanocarriers are gaining much attention due to their versatile multifunctional
activities, including disease diagnosis and treatment. Recently, clinical applications of
nano-drug delivery systems for cancer treatment pose a challenge due to their limited cellular uptake,
low bioavailability, poor targetability, stability issues, and unfavourable pharmacokinetics.
To overcome these issues, researchers are focussing on stimuli-responsive systems. Nanocarriers
elicit their role through endogenous (pH, temperature, enzyme, and redox) or exogenous (temperature,
light, magnetic field, ultrasound) stimulus. These systems were designed to overcome the
shortcomings such as non-specificity and toxicity associated with the conventional drug delivery
systems. The pH variation between healthy cells and tumor microenvironment creates a platform
for the generation of pH-sensitive nano delivery systems. Herein, we propose to present an
overview of various internal and external stimuli-responsive behavior-based drug delivery systems.
Herein, the present review will focus specifically on the significance of various pH-responsive
nanomaterials such as polymeric nanoparticles, nano micelles, inorganic-based pH-sensitive drug
delivery carriers such as calcium phosphate nanoparticles, and carbon dots in cancer treatment.
Moreover, this review elaborates the recent findings on pH-based stimuli-responsive drug delivery
systems with special emphasis on our reported stimuli-responsive systems for cancer treatment.