Chiroptical properties, binding affinity, and photostability of a conjugated zinc porphyrin dimer complexed with left-handed Z-DNA and right-handed B-DNA.

We have studied the UV-vis absorption and chiroptical properties, binding affinity and photostability of a conjugated positively charged butadiyne-linked Zn(ii) porphyrin dimer bound to DNA sequence poly(dG-dC)2. Right-handed B-DNA, spermine-induced Z-DNA and Co(iii)-induced Z-DNA have been explored. Resonance light scattering (RLS) spectra showed formation of porphyrin aggregates in the presence of all DNA forms with the largest aggregates formed with B-DNA.

Enhanced Photodynamic Selectivity of Nano-Silica-Attached Porphyrins Against Breast Cancer Cells.

The synthesis and characterization of bare silica (4 nm in diameter) nanoparticle-attached meso-tetra(N-methyl-4-pyridyl)porphine (SiO(2)-TMPyP, 6 nm in diameter) are described for pH-controllable photosensitization. Distinguished from organosilanes, SiO(2) nanoparticles were functionalized as a potential quencher of triplet TMPyP and/or singlet oxygen ((1)O(2)) at alkaline pH, thereby turning off sensitizer photoactivity. In weak acidic solutions, TMPyP was released from SiO(2) surface for efficient production of (1)O(2).

Imidazole-modified porphyrin as a pH-responsive sensitizer for cancer photodynamic therapy.

5,10,15,20-Tetrakis(N-(2-(1H-imidazol-4-yl)ethyl)benzamide)porphyrin produced twice as many singlet oxygen ((1)O(2)) molecules at pH 5.0 (quantum yield 0.53 ± 0.

"Boom" and "Bust" cycles in virus growth suggest multiple selective forces in influenza a evolution.

Background: Influenza A virus evolution in humans is driven at least in part by mutations allowing the virus to escape antibody neutralization. Little is known about the evolution of influenza in birds, a major reservoir of influenza A.

Methods: Neutralizing polyclonal antiserum was raised in chicken against reassortant influenza virus, CalX, bearing the hemagglutinin (HA) and neuraminidase (NA) of A/California/7/2004 [H3N2].