Inorganic nanoparticles as scaffolds for bioorthogonal catalysts.

Bioorthogonal transition metal catalysts (TMCs) transform therapeutically inactive molecules (pro-drugs) into active drug compounds. Inorganic nanoscaffolds protect and solubilize catalysts while offering a flexible design space for decoration with targeting elements and stimuli-responsive activity. These "drug factories" can activate pro-drugs in situ, localizing treatment to the disease site and minimizing off-target effects. Inorganic nanoscaffolds provide structurally diverse scaffolds for encapsulating TMCs. This ability to define the catalyst environment can be employed to enhance the stability and selectivity of the TMC, providing access to enzyme-like bioorthogonal processes. The use of inorganic nanomaterials as scaffolds TMCs and the use of these bioorthogonal nanozymes in vitro and in vivo applications will be discussed in this review.