Effects of membrane composition and lipid structure on the photopolymerization of lipid diacetylenes in bilayer membranes

Wang

Photochem & Photobiology

et al. 1992

The natural product 2-chloro-3,11-tridecadiene-5,7,9-triyn-1-ol (1) photosensitized the inactivation of Escherichia coli in the presence of near-ultraviolet light (320-400 nm; NUV) under both aerobic and anaerobic conditions. A series of E. coli strains differing in DNA repair capabilities and catalase proficiency exhibited indistinguishable inactivation kinetics following treatment with the chemical plus NUV. The presence of carotenoids did afford some protection to E. coli against inactivation under aerobic conditions, consistent with the involvement of singlet oxygen. The photosensitized hemolysis of human erythrocytes occurred more rapidly in the absence than in the presence of oxygen. Aerobically, the onset of hemolysis was partially inhibited by NaN3 and by 2,6-di-t-butyl-4-methylphenol (BHT) but not by superoxide dismutase (SOD). The aerobic lipid peroxidation observed in the membranes of erythrocyte ghosts was completely inhibited by BHT, and partially by NaN3, but not by SOD. These results suggest that either lipid peroxidation of the membrane is not the main cause of photohemolysis or that BHT has insufficient access to intact erythrocyte lipids to protect them. Aerobically, crosslinking of membrane proteins was also observed; it was not affected by SOD, but was partially inhibited by BHT and NaN3. The anaerobic photosensitized hemolysis of erythrocytes was more rapid; a radical mechanism was suggested since BHT inhibited the hemolysis to a greater extent than under aerobic conditions. Neither lipid peroxidation nor protein crosslinking was observed under conditions believed to be anaerobic. A light-dependent electron transfer to cytochrome c was obtained under argon but not under oxygen. Although induced mutations were not observed in the experiments with E. coli, 1 was capable of damaging both supercoiled pBR322 and Haemophilus influenzae transforming DNA in a manner that seemed to be equivalent under aerobic and anaerobic conditions. In conclusion, 1 can behave as typical photodynamic molecule under aerobic conditions but, in contrast to most photodynamic molecules, it is also phototoxic under anaerobic conditions. The extent to which the radical reactions detected under anaerobic reactions compete with the photodynamic processes when oxygen is present is not known.

Section: Discussionmentioning

confidence: 61%

PHOTOSENSITIZATION BY 2‐CHLORO‐3, 11‐TRIDECADIENE‐5, 7, 9‐TRIYN‐1‐OL: DAMAGE TO ERYTHROCYTE MEMBRANES, Escherichia coli, AND DNA

Wang

Photochem & Photobiology

et al. 1992

Designed Monomers and Polymers

“…The synthesis and property investigations of the phosphatidylcholine-analogue-containing polymers and phospholipid polymers are of increasing interest, not only because the famous membrane model of Singer and Nicolson, which pictures a double layer formed by a lipid matrix and proteins, but also because phospholipids are the most abundant among the lipids found in membranes [26]. During the past three decades, several groups focused their interest and attention on the polymerizable phospholipids, e.g., Nakaya et al [27][28][29][30][31][32][33][34][35][36][37][38][39], Regen et al [40][41][42][43], Ringsdorf et al [44][45][46][47][48], Chapman et al [49][50][51][52][53][54][55][56], O'Brien et al [57][58][59], Tsuchida et al [60], Singh et al [61] and Ishihara [62] have incorporated many polymerizable groups into various lipid structures to prepare phospholipid polymers and investigate their properties and potential applications.…”

Section: Aibnmentioning

confidence: 99%

Recent progress of phospholipid polymers

Nakaya¹,

Li²

2003

Since in 1982 the rst phosphatidylcholineanalogues-containingvinyl monomer 2-(methacryloyloxy)ethyl-2-(trimethylammonium)ethyl phosphate (MTP) was reported, more and more attention has focused on its polymers, as phospholipid polymers have been found to show excellent biocompatibility. We reviewed the progress of phospholipid polymers in 1997 which covered literature from 1974 to 1997; and mainly focused on phosphatidylcholineanalogues-containingvinyl polymers. This review re ects mainly recent research (i.e., mostly later than 1997) and important development progress on polymeric polyphospholipid analogues. A variety of approaches for design, synthesis, characterization, property investigation and potential applications for phospholipid-analoguecontaining polyurethanes and 2-methacryloyloxyethylphosphorylcholine-containing polymers have been extensivelydiscussed. The polymeric phospholipid analogues include polymers such as side-and main-chain types of phosphatidylcholine-analogue-containing polyurethanes, side-and main-chain types of phosphatidylcholine-analogue-containing segmented polyurethanes, phosphatidylcholineanalogue-grafted polyurethanes, 2-methacryloyloxyethylphosphorylcholine-containing polymers, 2-methacryloyloxyethylphosphorylcholine-modi ed acrylamide hydrogel, etc. Design and synthesis of phosphatidylcholine-analogue-containing diols and their polyurethanes with various commercially available diisocyanates and phosphatidylcholine-analogue surface-modi ed polyurethanes are described. New ring-opening reagents such as 2-dimethylaminoethanol for the main-chain type of phosphatidylcholine-analogue-containing polyurethanes, N -methyldiethanolamine for the sidechain type of phosphatidylcholine-analogue-containing polyurethanesand trimethylamine for grafting phosphatidylcholine-analogue-containing vinyl monomers are discussed. A general reaction route to design and synthesize phosphatidylcholine-analogue-containing diols and polyurethanes is summarized. Various phosphatidylcholine-analogue-containing segmented polyurethanes are also discussed. Various phosphatidylcholine-analogue-containing diols, together with 1,4-butanediol or ethylenediamine as chain extender were used to synthesize phosphatidylcholine-analogue-containing segmented polyurethanes or polyurethaneureas, which are based on diphenylmethane diisocyanate and various types of soft segments such as a polycarbonate,polyether, polyester and hydrocarbon diols. Character-310 T. Nakaya and Y. Li ization techniques for phosphatidylcholine-analogue-containing polyurethanes and polymers are also described. These include infra-red spectroscopy, 1 H-NMR, viscosity and gel-permeation chromatography measurements for bulk property; X-ray diffraction methods for structure; dynamic viscoelasticity and tensile measurements for mechanical properties. Moreover, attenuated total re ectanceFourier transform infrared spectroscopy,electron spectroscopy for chemical analysis and contact angle measurements for surface properties are all described. Hemocompatibility ...

“…Of the various polymerizable groups that have been incorporated into amphiphiles, diacetylene groups have been the most widely studied (Hub et al, 1980;Johnston et al, 1980;O'Brien et al, 1981;Lopez et al, 1982a;Lopez et al, 1982b …”

Section: Endocytosismentioning

confidence: 99%

Photoinduced Fusion of Liposomes

Bennett¹,

O’Brien²

1994

J. Am. Chem. Soc.

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