Engineered flavoproteins as bioorthogonal photo-triggers for the activation of metal-based anticancer prodrugs.

A multifunctional hybrid constructed for controlling the delivery and activation of Pt anticancer agents is described herein. We employed consensus tetratricopeptide repeat protein (CTPR) for the covalent co-anchoring of riboflavin (photocatalyst) and a Pt(IV) prodrug complex. The Pt-loaded flavoprotein induced a 40% reduction in PANC-1 cell viability as a result of the photocatalytic formation of cisplatin.

Synthesis, Characterization and Photoactivation Studies on the Novel Pt(IV)-Based [Pt(OCOCH)(phterpy)] Complex.

Photoactivatable Pt(IV) prodrugs represent nowadays an intriguing class of potential metal-based drugs, endowed with more chemical inertness in their oxidized form and better selectivity for the target with respect to the clinically established Pt(II) compounds. In fact, they have the possibility to be reduced by light irradiation directly at the site of interest. For this reason, we synthesized a new Pt(IV) complex, [Pt(OCOCH)(4'-phenyl-2,2':6',2''-terpyridine)][CFSO] (), that is well soluble in aqueous medium and totally unreactive towards selected model biomolecules until its reduction.

Enhancing the Photocatalytic Conversion of Pt(IV) Substrates by Flavoprotein Engineering.

Our recent work demonstrates that certain flavoproteins can catalyze the redox activation of Pt(IV) prodrug complexes under light irradiation. Herein, we used site-directed mutagenesis on the mini singlet oxygen generator (mSOG) to modulate the photocatalytic activity of this flavoprotein toward two model Pt(IV) substrates. Among the prepared mutants, Q103V mSOG displayed enhanced catalytic efficiency as a result of its longer triplet excited-state lifetime.

Catalysis Concepts in Medicinal Inorganic Chemistry.

Catalysis has strongly emerged in the field of medicinal inorganic chemistry as a suitable tool to deliver new drug candidates and to overcome drawbacks associated to metallodrugs. In this Concept article, we discuss representative examples of how catalysis has been applied in combination with metal complexes to deliver new therapy approaches. In particular, we explain key achievements in the design of catalytic metallodrugs that damage biomolecular targets and in the development of metal catalysis schemes for the activation of exogenous organic prodrugs.