Translational progress of stimulus-responsive smart nanocarrier platforms for cancer theranostics: a review

Smart drug delivery systems (SDDS) have the capability to respond to the unique conditions of the tumor microenvironment (TME) for improved anticancer efficacy and reduced toxicity to normal tissues. The TME is characterized by various physicochemical changes such as altered redox potential, acidic pH, hyperthermia, and the abnormal expression of various tumor- associated antigens andenzymes have drawn significant interest in the use of stimulus-responsive nanocarriers for cancer theranostics. The stimuli -responsive nanocarriers are developed to respond to external (ultrasound, light, magnetic field, thermal, etc.) as well as to the internal stimuli (pH, hypoxia, redox potential and enzymes, etc.) for effective delivery of therapeutic and imaging agents to the targeted sites. Smart nanocarriers encapsulated drug delivery systems such as liposomes, dendrimers, micelles, quantum dots, mesoporous silica nanoparticles, carbon nanotubes, gold nanoparticles, etc. are under development for tackling cancer progression effectively and are currently undergoing clinical evaluation to assess their safety and efficacy against various cancers. The article highlights the recent advances in stimuli -responsive smart nanocarriers, with particular emphasis on their integration into a unified theranostic approach for both cancer diagnosis and treatment.