A tumor consists of not only cancer cells but also an ecosystem including
different subpopulations. Cancer stem cells (CSCs) are a rare subpopulation in the
tumor cell population. Traditional therapies, such as chemotherapy and radiotherapy
target cancer cells except for CSCs. Therefore, the self-renewal and colony formation
capacity of CSCs provides the recurrence of tumors as well as drug resistance.
Different strategies are used to eradicate CSCs with the knowledge of CSC properties.
The recent technologic revolution gives a chance to design nanoscale medicines for the
effective treatment of CSCs. Nanoparticle-based delivery systems improve the
transport of traditional therapeutic drugs across biological barriers with maximum
bioavailability, less toxicity, and side effects, and take advantage in combination with
specific CSC targets, controlled and site-specific release. This chapter summarizes the
current models of CSCs, the molecular mechanisms leading to metastases and drug
resistance of CSCs, strategies to target CSCs, examples of currently approved
nanomedicine drugs and future perspectives.
Keywords: Biodistribution, Cancer stem cell, Chemosensitivity, Chemotherapy, Differentiation, Drug delivery system, Drug resistance, Epithelial-to-mesenchymal transition, Metastasis, Nanomedicine, Nanoparticle, Nanotechnology, Radiotherapy, Regenerative medicine, Self-renewal, Stability, Solubility, Traditional therapy, Tumor-initiating cell, Tumor relapse.
