Background: Rapid developments in the field of nanoparticles during the last decades have
led to its increased application in drug delivery approaches. The advantages of nano-based drug delivery
systems include improved therapeutic efficacy of drugs and the reduction of side effects.
Objective: This review aims to highlight advances in stimuli-triggered drug delivery approaches using
polymeric nanoparticles with a focus on pH-sensitive drug- and theranostic delivery systems.
Results and Conclusion: Of the various organic/inorganic nanoparticles, polymeric nanoparticles
have fulfilled an integral role in the advancement of drug delivery systems by virtue of the ease to incorporate
and modify targeting moieties in combination with controlled drug release over prolonged
periods. Furthermore, polymeric nanoparticles facilitate theranostic treatment by the incorporation of
imaging agents in addition to therapeutics. Recently, stimuli-responsive polymeric nanoparticles
emerged as smart drug carriers, in which drug release is affected by physical and/or chemical structural
changes induced by a specific stimulus (e.g. pH, temperature, and specific enzymes). The use of
these nanocomposites reduces premature drug release and maintains effective drug levels at the pathological