“…On a different note, in the last 10 years, much effort has been invested in studying the use of catalytic metal complexes for in-cells applications [ 38 , 39 , 40 ]. Particularly, the use of compounds capable of performing functional group modifications inside cells has attracted growing interest [ 38 , 39 , 40 ]. Such transformations not only allow the in-cells activation of pro-drugs or fluorophores through reduction [ 41 , 42 ] or deprotection of functional groups [ 43 , 44 , 45 , 46 ], but can also alter the homeostasis and metabolism of the cells via oxidation/reduction of molecules such as glutathione, nicotinamide dinucleotide or pyruvate/lactate [ 47 , 48 , 49 , 50 , 51 , 52 ].…”