The new amphiphilic BODPY-porphyrin conjugate BZnPP and its precursor BZnPH were synthesised, and their linear and two-photon photophysical properties, together with their cellular uptake and photo-cytotoxicity, were studied. This amphiphilic conjugate consists of a hydrophobic BODIPY moiety and a hydrophilic tetra(ethylene glycol) chain bridging a cationic triphenylphosphonium group to an amphiphilic porphyrin ZnP through acetylide linkers at its meso positions. A large two-photon absorption cross-section (σ=1725 GM) and a high singlet oxygen quantum yield (0.52) were recorded. Intense linear- and two-photon-induced red emissions were also observed for both BZnPP and BZnPH. Further in vitro studies showed that BZnPP exhibited very efficient cellular uptake and strong photocytotoxic but weak dark cytotoxic properties towards human breast carcinoma MCF-7 cells. In summary, the two-photon-induced emission and the potent photo-cytotoxicity of BZnPP make it an efficacious dual-purpose tumour-imaging and photodynamic therapeutic agent in the tissue-transparent spectral windows.

A series of cationic lanthanide porphyrinate complexes of the general formula [(Por)Ln(H₂O)₃]⁺ (Ln³⁺=Yb³⁺ and Er³⁺) were synthesized in moderate yields through the interaction of meso-pyridyl-substituted porphyrin free bases (H₂Por) with [Ln{N(SiMe₃)₂}₃]⋅x [LiCl(thf)₃], and the corresponding neutral derivatives [(Por)Ln(L_OMe)] (L_OMe⁻=[(η⁵-C₅H₅)Co{P(O)(OMe)₂}₃]⁻) were also prepared from [(Por)Ln(H₂O)₃]⁺ by the addition of the tripodal anion, L_OMe⁻, an effective encapsulating agent for lanthanide ions. Furthermore, the water-soluble lanthanide(III) porphyrinate complexes—including [(cis-DMPyDPP)Yb(H₂O)₃]Cl₃ (cis-DMPyDPP=5,10-bis(N-methylpyridinium-4′-y1)-15,20-di(phenyl)porphyrin), [(trans-DMPyDPP)Yb(H₂O)₃]Cl₃ (trans-DMPyDPP=5,15-bis(N-methylpyridinium-4′-y1)-10,20-di(phenyl)porphyrin), [(TMPyP)Yb(L_OMe)]I₄, and [(TMPyP)Er(L_OMe)]I₄ (TMPyP=tetrakis(N-methylpyridinium-4-y1)porphyrin)—were obtained by methylation of the corresponding complexes with methyl iodide and unambiguously characterized. The binding interactions and photocleavage activities of the water-soluble lanthanide(III) porphyrinate complexes towards DNA were investigated by UV-visible, fluorescence, and near-infrared luminescence spectroscopy, as well as circular dichroism and gel electrophoresis.

A series of (4-cyanophenyl)porphyrins have been prepared and structurally characterized by ¹H NMR, IR and UV/Vis spectroscopy, mass spectrometry, and elemental analysis. The relative singlet-oxygen quantum yields, two-photon absorption cross-sections and DNA photocleavage activities of these porphyrins were measured. The results show that (4-cyanophenyl)porphyrins with a properly designed hydrophobic/hydrophilic balance for better cellular uptake have potential application in two-photon-absorption photodynamic therapy. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)