title: Enhancement of photodynamic inactivation against Pseudomonas aeruginosa by a nano-carrier approach.
abstract: As pathogens steadily develop resistance to widely used antibiotics, new methodologies for their efficient inactivation must be developed. Photodynamic therapy is an upcoming technique that provides an alternative option for treating pathogenic infections. The efficiency of photodynamic therapy has been limited by the use of aqueous mediums for dispersing photosensitising agents. Toluidine Blue O (TBO) was chosen for this study as a cationic photosensitiser to inhibit Gram-negative bacterium Pseudomonas aeruginosa. Enhanced delivery of the photosensitiser was ensured by utilising an essential oil-based microemulsion. The efficiency of photodynamic therapy was further improved by the use of a chemical penetration enhancer to improve permeability of the bacterial outer membrane. TBO accumulation patterns in neonate pig skin were studied using confocal laser scanning microscopy. The physicochemical properties of the TBO loaded microemulsion, including UV-vis absorbance, size distribution and zeta potential, were analysed to understand the enhanced antimicrobial activity. Confocal laser scanning microscopy confirmed the formation of a TBO reservoir in the skin by the TBO-loaded microemulsions. TBO (5 μg/mL) in the vehicles significantly inhibited the growth of P. aeruginosa. All these efforts resulted in inhibition obtained at a drug concentration and light intensity much lower than what is reported by the works of previous investigators.
authors.affiliation: Graduate Institute of Biochemical and Biomedical Engineering, Chang Gung University, 259, Wen-Hwa First Road, Kwei-Shan, Tao-Yuan 333, Taiwan.
authors.forename: Bishakh
authors.initials: B
authors.lastname: Rout
authors.affiliation: Graduate Institute of Biochemical and Biomedical Engineering, Chang Gung University, 259, Wen-Hwa First Road, Kwei-Shan, Tao-Yuan 333, Taiwan; Research Center for Industry of Human Ecology, Chang Gung University of Science and Technology, 261, Wen-Hwa First Road, Taoyuan, Taiwan; Department of Ophthalmology, Chang Gung Memorial Hospital, 5, Fu-Hsing Street, Taoyuan, Taiwand College of Medicine, Chang Gung University, 259, Wen-Hwa First Road, Taoyuan, Taiwan. Electronic address: chl@mail.cgu.edu.tw.
authors.forename: Chi-Hsien
authors.initials: CH
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology, Chang Gung Memorial Hospital, 5, Fu-Hsing Street, Taoyuan, Taiwand College of Medicine, Chang Gung University, 259, Wen-Hwa First Road, Taoyuan, Taiwan; College of Medicine, Chang Gung University, 259, Wen-Hwa First Road, Taoyuan, Taiwan.
authors.forename: Wei-Chi
authors.initials: WC
authors.lastname: Wu
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D001402:B-Lymphocytes / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects; D004337:Drug Carriers / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry; D006825:Hybridomas; D008027:Light; D051379:Mice; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000528:radiation effects*; D012867:Skin / Q000378:metabolism; D013053:Spectrophotometry; D013552:Swine; D014048:Tolonium Chloride / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D004337:Drug Carriers; D004655:Emulsions; D017319:Photosensitizing Agents; D014048:Tolonium Chloride
keywords: EDTA; Essential oil; Photodynamic therapy; Photosensitiser; Toluidine Blue O