Generalized concept of catalysis for chemical reactions: Nanocatalysis in medicine as a paradigm

Catalysis is traditionally defined as the kinetic acceleration of a chemical reaction by reducing its activation energy , using catalysts, without altering the thermodynamic equilibrium of the reaction. In the past several decades, various novel catalytic modalities, such as photocatalysis , electrocatalysis , and sonocatalysis, have been developed via the change of the thermodynamic equilibria through external energy inputs; these are beyond the traditional concept of catalysis by reaction path regulation and therefore necessitate a broadened or generalized concept of “catalysis” to match current developments. Additionally, the concept of catalysis has recently been introduced in the biomedical field, resulting in the development of “nanocatalytic medicine.” Such a catalytic therapeutic strategy can be fulfilled both kinetically and thermodynamically by chemical reaction acceleration. In this perspective, we will present our thinking on the generalized concept of catalysis, mainly by referring to the most recent advances of “catalysis” in the field of nanocatalytic medicine. Challenges and opportunities: • Catalysis is traditionally defined as the kinetic acceleration of a chemical reaction. However, the current usage of the term “catalysis” has been largely broadened practically to mean chemical reaction accelerations that occur either kinetically or thermodynamically. • In the past several decades, various novel catalytic modalities, such as photocatalysis , electrocatalysis , and sonocatalysis, have been developed via the change of the thermodynamic equilibria through external energy inputs; these are beyond the traditional concept of catalysis by reaction path regulation and therefore necessitate a broadened or generalized concept of “catalysis.” • Nanocatalytic medicine has been developed via the fabrication of nano-sized catalysts to catalyze chemical reactions that regulate biochemical species in pathological microenvironments. Such a catalytic therapeutic strategy can be fulfilled both kinetically and thermodynamically by chemical reaction initiation or acceleration. The research advances in catalysis have invited a broadening of the concept of “catalysis” to match current developments. Meanwhile, the concept of catalysis has recently been introduced in the biomedical field, resulting in the development of “nanocatalytic medicine.” In this perspective, a generalized concept of catalysis has been presented, mainly by referring to the most recent advances of catalysis in the field of nanocatalytic medicine.