'Nano-in-nano' - Breaching the barriers of the tumor microenvironment using nanoparticle-incorporated nanofibers

Cancer is one of the leading causes of death worldwide. Despite significant efforts and advancements in cancer treatment, metastasis and tumor recurrence remain significant challenges that demand developing novel therapeutic strategies to reduce the disease burden. Recent advances in nanotechnology played a significant role in cancer diagnosis and treatment. Nano-in-nanofibers showed promising results in chemotherapy due to their high porosity, large surface area, high encapsulation efficiency, and controlled drug-release properties. Further, Nanoin-nanofibers offer improved potential in chemotherapy. The present article reviews the fundamental and theranostic applications of nanofibers in cancer research, such as chemotherapy (mono- and combinatorial therapy), gene therapy, thermal therapy, photodynamic therapy, cancer cell capturing, in vitro 3D cancer models, regulation of cancer cell fate processes, stimuli-responsive therapy, and sensor-based therapy. Furthermore, a thorough analysis of the current obstacles and future prospects in the clinical translation of Nano-in-nanofibers for cancer diagnostics and therapeutics has been discussed.