LEM wishes to thank The Engineering and Physical Sciences Research Council (EPSRC) for their support through a Doctoral Training Grant (awarded in 2007). ""Wate
Online PR News – 30-October-2017 – YT – LEM wishes to thank The Engineering and Physical Sciences Research Council (EPSRC) for their support through a Doctoral Training Grant (awarded in 2007). ""Water-soluble derivatives of hypocrellins can be safely delivered in blood plasma but lose their photodynamic activity in vivo due to poor cell uptake, while hydrophobic derivatives retaining their activity may aggregate in the blood plasma and block vascular networks. Considering both drug delivery and biological activity, surfactant-like hypocrellin B (HB) derivatives, sodium 12-2-HB-aminododecanoate (SAHB) and sodium 11,11ï¿½ï¿½-5,8-HB-dimercaptoundecanoate LY 294002 (DMHB), were first designed and then synthesized in the current work. Both SAHB and DMHB were photoactive, generating free radicals and reactive oxygen species, as confirmed by EPR and chemical measurements. Most importantly, DMHB was not only readily soluble, allowing preparation of an intravenous injection solution at a clinically acceptable concentration, but it was also more photodynamic therapy (PDT) active to human breast carcinoma MCF-7 cells than its parent HB under irradiation. The photodynamic activity was exactly identical to the 1O2 quantum yield and was not reduced by the improved water solubility, Doxorubicin ic50 suggesting an independent hydrophilicity or lipophilicity. To our knowledge, this is a new strategy that possesses general significance for converting hydrophobic photosensitizers into clinically usable PDT drugs. ""Microbial biofilm architecture contains numerous protective features, including extracellular polymeric material that render biofilms impermeable to conventional antimicrobial agents. This study evaluated the efficacy of antimicrobial photodynamic inactivation (aPDI) of Enterococcus faecalis biofilms. The ability of a cationic, phenothiazinium photosensitizer, methylene blue (MB) and an anionic, xanthene photosensitizer, Obeticholic Acid nmr rose bengal (RB) to inactivate biofilms of E. faecalis (OG1RF and FA 2-2) and disrupt the biofilm structure was evaluated. Bacterial cells were tested as planktonic suspensions, intact biofilms and biofilm-derived suspensions obtained by the mechanical disruption of biofilms. The role of a specific microbial efflux pump inhibitor (EPI), verapamil hydrochloride in the MB-mediated aPDI of E. faecalis biofilms was also investigated. The results showed that E. faecalis biofilms exhibited significantly higher resistance to aPDI when compared with E. faecalis in suspension (P?