Stabilisation of lipid membrane-incorporated porphyrin derivative aqueous solutions and their photodynamic activities.

Lipid membrane-incorporated porphyrin derivatives (LMIPors) having three phenyl moieties and one pyridyl or pyridinium moiety at the meso-positions were more stable than LMIPors having phenyl and/or pyridyl moieties. The former two LMIPors showed high photodynamic activity toward cancer cells under photoirradiation at wavelengths over 600 nm, which are the most suitable for photodynamic therapy. The photodynamic activities were greater than that of Photofrin, which is currently the main drug employed clinically as a photosensitiser. The results represent significant progress toward the optimisation of LMIPors as photosensitisers.

Effect of meso Positioned Substituents on the Stability and Photodynamic Activity of Lipid-Membrane-Incorporated Porphyrin Derivatives.

In this study we prepared aqueous solutions of lipid-membrane incorporated tetraarylporphyrins and tetrapyridylporphyrin (LMIPors) by the injection method using dimethyl sulfoxide. The porphyrins with proton-donor groups at the meso position afforded stable aqueous solutions of LMIPors. However, although tetrakis(carboxyphenyl)porphyrin was scarcely incorporated in lipid membranes, it was soluble in water. Among these LMIPors, the photodynamic activity of tetrakis(hydroxyphenyl)porphyrin was higher than that of tetrakis(aminophenyl)porphyrin. This was attributed to the self-aggregation of a part of tetrakis(aminophenyl)porphyrin in the liposomes, which induced self-quenching and the consequent decrease of its photodynamic activity.

Photo-triggered cargo release from liposome chlorin e6-bearing pullulan hybrid nanoparticles via membrane permeabilization.

A liposome chlorin e6-bearing pullulan nanogel hybrid was prepared as a light-triggered payload release platform. The current system enabled manipulation of the release profile of model drugs encapsulated by liposomes. Gelatin hydrogels that comprised hybrid nanoparticles could successfully control the delivery of cargo molecules to human mesenchymal stem cells with light stimuli without injury to the cells.

Tailoring a Thermally Stable Amorphous SiOC Structure for the Separation of Large Molecules: The Effect of Calcination Temperature on SiOC Structures and Gas Permeation Properties.

A SiOC membrane with high oxidative stability for gas separation was tailored by utilizing vinyltrimethoxysilane, triethoxysilane, and 1,1,3,3-tetramethyldisiloxane as Si precursors. Amorphous SiOC networks were formed via the condensation of Si-OH groups, the hydrosilylation of Si-H and Si-CH=CH2 groups, and a crosslinking reaction of Si-CH3 groups, respectively. The crosslinking of Si-CH3 groups at temperatures ranging from 600 to 700 °C under a N2 atmosphere was quite effective in constructing a Si-CH2-Si unit without the formation of mesopores, which was confirmed by the results of N2 adsorption and by the gas permeation properties. The network pore size of the SiOC membrane calcined at 700 °C under N2 showed high oxidative stability at 500 °C and was appropriate for the separation of large molecules (H2/CF4 selectivity: 640, H2/SF6: 2900, N2/CF4: 98). A SiOC membrane calcined at 800 °C showed H2/N2 selectivity of 62, which was approximately 10 times higher than that calcined at 700 °C because the SiOC networks were densified by the cleavage and redistribution reactions of Si-C and Si-O groups.

Adsorption of tetrakis(4-sulfophenyl)porphyrin onto liposomal surfaces composed of neutral diacylphosphatidylcholine and release by cyclodextrin.

Anionic tetrakis(4-sulfophenyl)porphyrin (TPPS) interacts with liposomal surfaces composed of neutral diacylphosphatidylcholine at high lipid concentrations. TPPS interacted with liposomal surfaces through four contact points. The association constant was obtained to be 9.0 × 105 M-4. TPPS was peeled off the liposomal surfaces by the addition of cyclodextrin.