Smart internal and external stimuli-responsive nanocarriers for image-guided drug delivery and therapy

Abstract In recent decades, the advancements in nanotechnology, nanochemistry, and surface modification have inspired the booming development of multifunctional and stimuli-sensitive nanocarriers, which enable effective delivery therapeutic cargos to disease sites, then spontaneously response to local pathological factors or external physical stimuli. Such nanocarriers could improve drug delivery and mediate tumor-specific release spatiotemporally in an on-demand fashion, offering powerful weapons for an effective cancer therapy. Moreover, the external stimuli show promise performance in some therapy modalities, including photothermal, photodynamic, magnetic hyperthermia, and sonodynamic therapy besides chemotherapy or gene therapy. Meanwhile, the concept of image-guided therapy has been proposed. By coencapsulating imaging contrast agents into nanocarriers, real-time monitoring of drug delivery, release, and effectiveness could be achieved for better planning and adjusting therapy strategy during treatment. In this chapter, we summary recent advances in stimuli-responsive nanocarriers for image-guided therapy, including introduction of various imaging modalities and their role in image-guided therapy, and different kinds of stimuli-responsive systems (exogenous or endogenous factors responsive) applied in image-guided therapy.