Detachable Fluorinated Phthalocyanine Aggregates for Carrier‐Free PDT: Effect of Axial Symmetry on Dynamic Morphological Adjustment and Photodynamic Efficiency

Abstract Chemical structure plays a critical role in determining the properties and aggregation behavior of materials. In this study, controlled axial modification of one or two PEG 5000 molecules is performed on the central metal (Sn) of the fluorinated phthalocyanine to obtain asymmetric and symmetric amphiphilic polymers, denoted as SnPcP and SnPc2P, respectively. The anisotropic aggregation of fluorinated phthalocyanine guides the construction of dynamic aggregates with diverse architectures. Dynamic aggregates can be formed by seed‐growth at high concentrations in selective solvents, detaching into pseudo‐axisymmetric J ‐aggregated oligomers (seeds, <20 nm) at low concentrations for the asymmetric SnPcP. For SnPc2P, the symmetrically entangled PEG prevents the orderly arrangement of fluorinated phthalocyanine and forms seeds independently; aggregates are preferred at high concentrations, and unimers (seeds, ca. 10 nm) can be obtained when diluted. Both photosensitizers (PSs) exhibit outstanding photostability and oxygen‐carrying capacity, and additionally, SnPcP displays higher photodynamic efficiency at low concentrations, probably due to that J ‐aggregation elevates the intersystem crossing efficiency. In vitro and in vivo experiments demonstrate the extraordinary photodynamic therapy capacity of SnPcP. This study provides a universal strategy for the modular design of dynamic aggregates by constructing detachable PS primitives with pseudo/axisymmetric structures.