Nanoformulation of Lipophilic Osmium Photosensitizers in Liposomes and Micelles as a General Strategy for Improving Reproducibility and Reducing Quenching ^†

Abstract Nanoformulation of an osmium photosensitizer within liposomes and micelles is used to improve the water‐solubility of this highly lipophilic molecule. This highlight report describes a recent paper by Cameron, Obaid and McFarland on this topic and discusses the context for this report. Nanoformulation has been explored as a strategy before, but this represents the first usage of this strategy with highly potent metal‐based photosensitizers having phototherapeutic indices (PIs) in excess of 10 4 . The nanoformulation strategy is effective due to reducing aggregation and self‐quenching of the photosensitizer molecules.