Localized nanotheranostics: recent developments in cancer nanomedicine

Since decades, conventional diagnosis and treatment strategies for cancer have been practiced widely despite their expensive and time-consuming process. These conventional contrast and therapeutic agents suffer from various side-effects such as low radiodensity and image resolution, rapid clearance, non-specific biodistribution, poor tumor accumulation, high-dose and multiple-dose requirements, nephrotoxicity, uncontrolled exposure of high electromagnetic radiations, whole-body scans, and so on. Therefore, nanosized imaging and therapeutic probes have been proposed recently owing to their promising efficacy and negligible side-effects. However, these nanoplatforms are struggling deeply to find their clinical translational relevance. Integrating targeting ligands with diagnostic and therapeutic agents within a single system at the nanoscale resulted in localized nanotheranostics. Furthermore, the conceptualized nanotheranostics has been recognized as a clinical 'weapon' for localized cancer nanomedicine. In this review, we have covered a wide spectrum of recent developments in cancer nanotheranostics. Numerous examples of functional nanohybrids and clinical relevant materials with their multimode imaging and therapeutics have been addressed here. On the other hand, the importance of combination therapies, imaging-guided tumor regression, deep tissue visualization, localized diagnosis and tumor ablation, manipulation of the tumor microenvironment, and so on have been discussed here. Overall, localized and stimuli responsive nanosized multifunctional platforms have proved their superiority over conventional diagnosis and therapies. (C) 2020 The Author(s). Published by Elsevier Ltd.