Development
of bioinspired nanomachines with an efficient propulsion
and cargo-towing has attracted much attention in the last years due
to their potential biosensing, diagnostics, and therapeutics applications.
In this context, self-propelled synthetic nanomotors are promising
carriers for intelligent and controlled release of therapeutic payloads.
However, the implementation of this technology in real biomedical
applications is still facing several challenges. Herein, we report
the design, synthesis, and characterization of innovative multifunctional
gated platinum–mesoporous silica nanomotors constituted of
a propelling element (platinum nanodendrite face), a drug-loaded nanocontainer
(mesoporous silica nanoparticle face), and a disulfide-containing
oligo(ethylene glycol) chain (S–S–PEG) as a gating system.
These Janus-type nanomotors present an ultrafast self-propelled motion
due to the catalytic decomposition of low concentrations of hydrogen
peroxide. Likewise, nanomotors exhibit a directional movement, which
drives the engines toward biological targets, THP-1 cancer cells,
as demonstrated using a microchip device that mimics penetration from
capillary to postcapillary vessels. This fast and directional displacement
facilitates the rapid cellular internalization and the on-demand specific
release of a cytotoxic drug into the cytosol, due to the reduction
of the disulfide bonds of the capping ensemble by intracellular glutathione
levels. In the microchip device and in the absence of fuel, nanomotors
are neither able to move directionally nor reach cancer cells and
deliver their cargo, revealing that the fuel is required to get into
inaccessible areas and to enhance nanoparticle internalization and
drug release. Our proposed nanosystem shows many of the suitable characteristics
for ideal biomedical destined nanomotors, such as rapid autonomous
motion, versatility, and stimuli-responsive controlled drug release.