Several
examples of nanosized therapeutic and imaging agents have been proposed
to date, yet for most of them there is a low chance of clinical
translation due to long-term in vivo retention and toxicity risks. The
realization of nano-agents that can be removed from the body after use
remains thus a great challenge. Here, we demonstrate that
non-equilibrium gold-iron alloys behave as shape-morphing nanocrystals
with the properties of self-degradable multifunctional nanomedicines.
DFT calculations combined with mixing enthalpy-weighted alloying
simulations predict that Au-Fe solid solutions can exhibit
self-degradation in aqueous environment if the Fe content exceeds a
threshold that depends upon element topology in the nanocrystals.
Exploiting a laser-assisted synthesis route, we experimentally confirm
that non-equilibrium Au-Fe nanoalloys have a 4D behavior, that is the
ability to change shape, size and structure over time, becoming
ultrasmall Au-rich nanocrystals. In vivo tests
