Smart nanotheranostic hydrogels for on-demand cancer management

•Address the importance of early cancer diagnosis for better prognosis.•Documents recent studies highlighting application of nanotheranostics against cancer.•Emphasis on reviewing nanotheranostic-hydrogels as new tools for cancer management. [Display omitted] Much research effort has been dedicated to unveiling the complexity of tumors for the development of effective treatment approaches. The idea of applying nanotheranostics for cancer management has transcended from a ‘hype to hope’ scenario. Furthermore, use of engineered hydrogels containing nanotheranostics has paved the path for generating smart cargos for effective diagnosis and remission. Hydrogels, used as reservoirs for smart nanotheranostics, facilitate the sustained release of drugs and imaging agents for a prolonged period of time, thereby assisting in early disease diagnosis, therapy, and prognosis. In this review, we discuss the use of engineered hydrogels as biomedical theranostic agents. Theranostics is a revolution in cancer therapy. Hydrogels have many implications as a drug delivery vehicle and theranostics hydrogels could be a model nanotherapeutic for simultaneous cancer diagnosis and treatment.