Scanning probe characterizations of porphyrin patterns created by nanografting were used to provide insight for the
molecular orientation and surface assembly of porphyrins with pyridyl and phenyl substituents. In-situ AFM provides
highly local views of the assembly of pyridyl-substituted porphyrins on surfaces of Au(111). Matrix self-assembled
monolayers(SAMs) of n-alkanethiols furnish a molecular ruler for calibrating height measurements. Nanografting can
be used for local measurements of the thickness of porphyrin films in situ by comparison with heights of n-alkanethiol
nanopatterns. When nanografted, pyridyl porphyrins were found to assemble onto gold directly into an upright
configuration, and surface binding is likely mediated through nitrogen-gold chemisorption.
Conjugates of <i>meso</i>-tetraphenylporphyrin to the cell targeted NLS SV40 and HIV-1 Tat 48-60 peptide sequences
were synthesized on solid-phase using optimized conjugation protocols. Polar groups were introduced at the periphery
of the prophyrin macrocycle, and their effect on the <i>in vitro </i>biological performance of the conjugates was evaluated. <i>In
vitro</i> biological studies using the new porphyrin conjugates in human HEp2 cells showed that the conjugates bearing the
HIV-1 Tat sequence were the most efficiently delivered within cells. The cellular uptake was also dependent on the
nature of the substituents at the periphery of the porphyrin macrocycle. On the other hand, the conjugates containing the
NLS SV40 peptide sequence and/or hydrophobic groups at the porphyrin periphery were the most phototoxic. The
subcellular distribution of the conjugates depended significantly on the nature of the peptide sequence and the overall
molecule charge. The conjugates delivered into the more sensitive ER were more phototoxic to the HEp2 cells than
those that localized mainly in the lysosomes.
The syntheses and properties of novel water-soluble phthalocyanies are reported, as well as new chemistry of tetrabutanoporphyrins aimed at the preparation of new, functionalizable, tribenzoporphyrin systems. The objective of the study is to provide new second-generation photosensitizing drugs, with long-wavelength absorption, for use in the photodynamic therapy of tumors.
The dark toxicity and singlet oxygen quantum yields of the zinc(II) complexes of the nido- and closo-carboranylporphyrins 4 and 5 are reported. Both carboranylporphyrins show very low toxicity towards V79 hamster lung fibroblast cells (IC<sub>50</sub> > 500 μM), display similar absorption and fluorescence emission spectra, and are efficient producers of singlet oxygen (quantum uilds of 0.72 in CD<sub>3</sub>OD and 0.45 in CHCl<sub>3</sub> were determined for 4 and 5, respectively). Our results indicate that the presence of nido- or closo-carborane cages bound via methylene linkages to the meso-phenyl groups, do not substantially alter the photosensitizing properties of porphyrin macrocycles. It is suggested that carboanylporphyrins could have dual application in the boron neutron capture therapy (BNCT) and photodynamic therapy (PDT) treatment of malignant brain tumors.
Efficient methods for the syntheses of porphyrin and chlorin dimers joined with variable length carbon units, either at meso positions or at (beta) -pyrrolic positions, are described. The in vivo testing results for some of the dimers are also discussed. The main objective of this work is to understand the structure/activity relationships among carbon-carbon linked dimers of porphyrins and chlorins. It is anticipated that this study will assist the authors in designing photosensitizers with required chemical and photochemical properties.