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Porphyrins bearing imidazolium salts were synthesized and used as N-heterocylic carbene (NHC) precursors for the preparation of gold(I) complexes. The dark toxicity and phototoxicity of the obtained compounds were investigated in vitro on MCF-7 breast cancer cells. The obtained data showed that porphyrins equipped with imidazolium salts are non-toxic in the dark and present interesting photodynamic properties. On the contrary, corresponding NHC-gold(I) complexes are not suitable photosensitizers for photodynamic therapy (PDT) applications. Their dark toxicity strongly depends on the nature of the linker between the porphyrin core and the NHC. This work was extended to the synthesis of a pyropheophorbide a derivative with a pendant imidazolium group for PDT applications using excitation wavelengths of 450 nm, 545 nm, and importantly of 650 nm.

The synthesis, characterization and study of optical properties of innovative tetrafunctionalized zinc(II) porphyrins with carbonic anhydrase (CA) inhibitors in sulfonamide and coumarin series are described. The synthetic methodology relies on the preparation of the porphyrin core by condensation of azido triethyleneglycol functionalized benzaldehyde derivative with pyrrole followed by its metalation and inhibitors coupling via Huisgen click‐reaction. The tetrafunctionalized zinc(II) porphyrin with coumarin moieties showed selective inhibition against tumour‐associated hCA IX and hCA XII versus the cytosolic off‐targets hCA I and hCA II. This compound was able to accumulate on cell membrane and to impair pancreas cancer cells (Capan‐1) proliferation in normoxic conditions with LC50 of 4.5 μM. Moreover, its optical properties revealed efficient photosensitizing properties, leading to cancer cells death under light irradiation, making this compound a suitable candidate for photodynamic therapy. [ABSTRACT FROM AUTHOR]

Diazachlorin and diazabacteriochlorin have been prepared through reduction of diazaporphyrin and their in vitro and in vivo activity in photodynamic therapy has been investigated. [ABSTRACT FROM AUTHOR]

Abstract: Periodic mesoporous organosilica nanoparticles emerge as promising vectors for nanomedicine applications. Their properties are very different from those of well‐known mesoporous silica nanoparticles as there is no silica source for their synthesis. So far, they have only been synthesized from small bis‐silylated organic precursors. However, no studies employing large stimuli‐responsive precursors have been reported on such hybrid systems yet. Here, the synthesis of porphyrin‐based organosilica nanoparticles from a large octasilylated metalated porphyrin precursor is described for applications in near‐infrared two‐photon‐triggered spatiotemporal theranostics. The nanoparticles display unique interconnected large cavities of 10–80 nm. The framework of the nanoparticles is constituted with J‐aggregates of porphyrins, which endows them with two‐photon sensitivity. The nanoparticle efficiency for intracellular tracking is first demonstrated by the in vitro near‐infrared imaging of breast cancer cells. After functionalization of the nanoparticles with aminopropyltriethoxysilane, two‐photon‐excited photodynamic therapy in zebrafish is successfully achieved. Two‐photon photochemical internalization in cancer cells of the nanoparticles loaded with siRNA is also performed for the first time. Furthermore, siRNA targeting green fluorescent protein complexed with the nanoparticles is delivered in vivo in zebrafish embryos, which demonstrates the versatility of the nanovectors for biomedical applications. [ABSTRACT FROM AUTHOR]

Porphyrins fused to imidazolium salts across two neighboring β-pyrrolic positions were used as N-heterocyclic carbene (NHC) precursors to anchor AuI-Cl complexes at their periphery. Synthesis of several thiolato-AuI complexes was then achieved by substituting chloride for thiolates. Photodynamic properties of these complexes were investigated: the data obtained show that the Au−S bonds could be cleaved upon irradiation. The proposed mechanism to explain the release of thiolate moiety involves the S atom oxidation by singlet oxygen generated in the course of irradiation. In view of photodynamic therapy (PDT) applications, these porphyrins fused to NHC-AuI complexes were tested as photosensitizers to kill MCF-7 breast cancer cells. Results show the important role played by the ancillary ligands (chloride versus thiolates) on the photodynamic effect. [ABSTRACT FROM AUTHOR]

In this work, we exploit the versatile function of cationic phosphonium-conjugated polythiophenes to develop multifunctional platforms for imaging and combined therapy (siRNA delivery and photodynamic therapy). The photophysical properties (absorption, emission and light-induced generation of singlet oxygen) of these cationic polythiophenes were found to be sensitive to molecular weight. Upon light irradiation, low molecular weight cationic polythiophenes were able to light-sensitize surrounding oxygen into reactive oxygen species (ROS) while the highest were not due to its aggregation in aqueous media. These polymers are also fluorescent, allowing one to visualize their intracellular location through confocal microscopy. The most promising polymers were then used as vectors for siRNA delivery. Due to their cationic and amphipathic features, these polymers were found to effectively self-assemble with siRNA targeting the luciferase gene and deliver it in MDA-MB-231 cancer cells expressing luciferase, leading to 30–50% of the gene-silencing effect. In parallel, the photodynamic therapy (PDT) activity of these cationic polymers was restored after siRNA delivery, demonstrating their potential for combined PDT and gene therapy. [ABSTRACT FROM AUTHOR]