Supramolecular activation of the photodynamic properties of porphyrinoid photosensitizers by calix[4]arene nanoassemblies

Abstract

Micellar-like nanocontainers ca. 40 nm in diameter of an amphiphilic calix[4]arene, encapsulate hydrophilic and hydrophobic phthalocyanine and porphyrin derivatives and effectively switch on their capability to photogenerate the cytotoxic singlet oxygen, otherwise totally precluded in water medium, with high quantum efficiency (Φ_Δ = 0.57 and 0.89). The photodynamic action of the supramolecular nanoassemblies is demonstrated by their remarkable inactivation under visible light irradiation of Staphylococcus aureus and Pseudomonas aeruginosa, representative Gram-positive and Gram-negative bacteria, respectively.