Stimuli-responsive drug-delivery nanocarriers (DDNs) have been increasingly reported
in the literature as an alternative for breast cancer therapy. Stimuli-responsive DDNs
are developed with materials that present a drastic change in response to intrinsic/chemical
stimuli (pH, redox and enzyme) and extrinsic/physical stimuli (ultrasound, light, magnetic
field and electric current). In addition, they can be developed using different strategies, such
as functionalization with signaling molecules, leading to several advantages, such as (a) improved
pharmaceutical properties of liposoluble drugs, (b) selectivity with the tumor tissue
decreasing systemic toxic effects, (c) controlled release upon different stimuli, which are all
fundamental to improving the therapeutic effectiveness of breast cancer treatment. Therefore,
this review summarizes the use of stimuli-responsive DDNs in the treatment of breast cancer.
We have divided the discussions into intrinsic and extrinsic stimuli and have separately detailed
them regarding their definitions and applications. Finally, we aim to address the ability
of these stimuli-responsive DDNs to control the drug release in vitro and the influence on
breast cancer therapy, evaluated in vivo in breast cancer models.