New Designs for Phototherapeutic Transition Metal Complexes

Abstract

In this Minireview, we highlight recent advances in the design of transition metal complexes for photodynamic therapy (PDT) and photoactivated chemotherapy (PACT), and discuss the challenges and opportunities for the translation of such agents into clinical use. New designs for light‐activated transition metal complexes offer photoactivatable prodrugs with novel targeted mechanisms of action. Light irradiation can provide spatial and temporal control of drug activation, increasing selectivity and reducing side‐effects. The photophysical and photochemical properties of transition metal complexes can be controlled by the appropriate choice of the metal, its oxidation state, the number and types of ligands, and the coordination geometry.

Metallodrugs are unique: opportunities and challenges of discovery and development

“…73 In PACT, light activation of an inert prodrug leads to the formation of photoproducts, which contribute to the therapeutic effects. 75,76 For example, Pt IV…”

Photoactivatable Protherapeutic Nanomedicine for Cancer

“…of the cell. [ 10 ] Ru(II), rhodium(III), or rhenium(I) complex with inert d 6 metal ions, on the other hand, are activated by photosubstitution. Under light irradiation, triplet excited states of metal‐to‐ligand character are generated, which interconvert into low‐lying triplet metal‐centered states, or d–d states.…”

“…These excited states have strong dissociative character, which leads to ligand substitution by solvents, typically water. [ 10 ]…”

Photoactivatable Platinum-Based Anticancer Drugs: Mode of Photoactivation and Mechanism of Action

“…With the rapid development of platinum-based anticancer complexes, several types of photoactivatable Pt(II) and Pt(IV) complexes were prepared, their modes of photoactivation were elucidated, and their antitumor effects were assessed [12]. So far, several excellent reviews have been published, which reported the development and achievement of photoactivatable platinum complexes [17][18][19]. However, no one has done a comprehensive summary on platinum drugs based on their photoactivation mechanism.…”