Carboranyl-Chlorin e6 as a Potent Antimicrobial Photosensitizer
نویسندگان
چکیده
Antimicrobial photodynamic inactivation is currently being widely considered as alternative to antibiotic chemotherapy of infective diseases, attracting much attention to design of novel effective photosensitizers. Carboranyl-chlorin-e6 (the conjugate of chlorin e6 with carborane), applied here for the first time for antimicrobial photodynamic inactivation, appeared to be much stronger than chlorin e6 against Gram-positive bacteria, such as Bacillus subtilis, Staphyllococcus aureus and Mycobacterium sp. Confocal fluorescence spectroscopy and membrane leakage experiments indicated that bacteria cell death upon photodynamic treatment with carboranyl-chlorin-e6 is caused by loss of cell membrane integrity. The enhanced photobactericidal activity was attributed to the increased accumulation of the conjugate by bacterial cells, as evaluated both by centrifugation and fluorescence correlation spectroscopy. Gram-negative bacteria were rather resistant to antimicrobial photodynamic inactivation mediated by carboranyl-chlorin-e6. Unlike chlorin e6, the conjugate showed higher (compared to the wild-type strain) dark toxicity with Escherichia coli ΔtolC mutant, deficient in TolC-requiring multidrug efflux transporters.
منابع مشابه
Polycationic photosensitizer conjugates: effects of chain length and Gram classification on the photodynamic inactivation of bacteria.
OBJECTIVES We have shown previously that a polycationic conjugate between poly-L-lysine and the photosensitizer chlorin(e6) was effective in photodynamic inactivation (PDI) of both Gram-positive and Gram-negative bacteria. In this report we explore the relationship between the size of the polylysine chain and its effectiveness for mediating the killing of Gram-negative and Gram-positive bacteri...
متن کاملSelective lethal photosensitization of methicillin-resistant Staphylococcus aureus using an IgG-tin (IV) chlorin e6 conjugate.
OBJECTIVES The growing resistance of methicillin-resistant Staphylococcus aureus (MRSA) to conventional antimicrobial agents necessitates the development of alternative approaches to preventing and treating infections. One such approach is photodynamic therapy, whereby target cells are treated with light-activated drugs (photosensitizers). This investigation aimed to determine whether the abili...
متن کاملEnergy Transfer in Ce0.85Tb0.15F3 Nanoparticles-CTAB Shell-Chlorin e6 System
Formation and electronic excitation energy transfer process in the nanosystem consisting of Ce0.85Tb0.15F3 nanoparticles, cetrimonium bromide (CTAB) surfactant, and chlorin e6 photosensitizer were studied. It was shown that chlorin e6 molecules bind to Ce0.85Tb0.15F3 NP in the presence of CTAB forming thus Ce0.85Tb0.15F3 NP-CTAB-chlorin e6 nanosystem. We consider that binding occurs via chlorin...
متن کاملThe inability of a bacteriophage to infect Staphylococcus aureus does not prevent it from specifically delivering a photosensitizer to the bacterium enabling its lethal photosensitization.
OBJECTIVES It has been demonstrated that the efficiency of lethal photosensitization can be improved by covalently binding photosensitizing agents to bacteriophage. In this study we have investigated whether a bacteriophage requires the capacity to infect the bacterium to enhance lethal photosensitization when linked to a photosensitizer. METHODS Tin (IV) chlorin e6 (SnCe6) was conjugated to ...
متن کاملDevelopment of a novel targeting system for lethal photosensitization of antibiotic-resistant strains of Staphylococcus aureus.
Light-activated antimicrobial agents (photosensitizers) are promising alternatives to antibiotics for the treatment of topical infections. To improve efficacy and avoid possible damage to host tissues, targeting of the photosensitizer to the infecting organism is desirable, and this has previously been achieved using antibodies and chemical modification of the agent. In this study we investigat...
متن کامل