Insight of nanomedicine strategies for a targeted delivery of nanotherapeutic cues to cope with the resistant types of cancer stem cells

Characteristics of small group of cancerous cells known as cancer stem cells (CSCs) or tumor initiating cells involve relapse, metastasis, and drug resistant which highly influence the available therapeutic processes. Tumoral drug resistance appears closely related to various acquire or intrinsic characteristics of CSCs e.g., detoxifying enzymes, drug efflux transporters, antiapoptotic protein overexpression, DNA repairability, specific morphology, and quiescence. The specific hypoxic stability and niche impart additional shield against anti-cancer therapeutic approaches for CSCs. Therefore, CSC-based therapeutics are intended to form the core of efficient anticancer strategies. Nanostructured constructs have demonstrated to possess promising applications e.g., targeted drug release, controlled delivery, CSC-targeting drugs, and the development of novel gene-specific diagnostic and treatment modalities. This review describes various drug resistant-related characteristics of CSCs and aim to summarize recent therapeutic and biomedical approaches using nanostructures (nanomedicines). The modification of components presents in extracellular matrix with the nanostructured constructs is considered as one of the promising strategies to upgrade the intra-tumoral drug delivery. Different CSCs-targeting therapies including photothermal therapy (PTT), photodynamic therapy (PDT), hyperthermia, and radiotherapy-based methodologies, which could serve as the novel combination of therapeutic approaches to eliminate CSCs and metastasis have also been described.