Fluorophores to fighters: BODIPY-metal complexes as next-gen anticancer prodrugs

Metal-coordinated complexes have been employed as effective anti-cancer agents with cis-platin being the foundation for the development of metal-based therapeutics. However, their use is greatly limited by their systemic toxicity, drug resistance and non-targeted approach. Progressing drug resistance has led to the use of combinatorial approaches for a multifaceted attack on cancer. Photodynamic therapy (PDT) is a clinically approved adjuvant chemotherapy that involves the use of a photosensitizer (PS), light and endogenous molecular oxygen (³O₂). Boron-dipyrromethene (BODIPY) dyes are a class of fluorophores that serve as promising PSs with excellent light-activated reactive oxygen species (ROS) generating capacity (for PDT) and light-to-heat conversion (for PTT) causing the thermal ablation of cancer cells. Conjugating a metal-based drug along with a PS and a targeting ligand to design a prodrug acts as a "magic packet" to target various cancers. This review elaborates the advances in the development of metallo-prodrugs adorned with a BODIPY cage as cancer theranostics. It highlights the engineering marvel of constructing prodrugs with high specificity and organelle-targeting ability.