The Interaction of Dose and Rate of Delivery Using Visible and Infrared Light to Inhibit Pseudomonas aeruginosa In vitro

Guffey, J. Stephen; Payne, William; Bednar, Annette

doi:10.4172/2469-410x.1000104

Cited by 4 publications

(6 citation statements)

References 19 publications

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“…As mentioned in the introduction, particular organisms respond differently to various wavelengths and intensities. Our previous work suggested a low rate of delivery increases inhibition of certain microbes, likely due to improved absorption of the energy …”

Section: Discussionmentioning

confidence: 99%

“…After mature growth was obtained, the photosensitiser, 10 mL of a 2.0 μmol/L solution of MB, was added to cover the surface growth of the test organism. Various concentrations of photosensitisers have been used by different investigators (0‐200 μmol/L and 0‐90 μg/mL) . With a variety of exposure times being utilised by separate investigators .…”

Section: Methodsmentioning

confidence: 99%

“…Various concentrations of photosensitisers have been used by different investigators (0-200 μmol/L and 0-90 μg/mL). 24 With a variety of exposure times being utilised by separate investigators. 25,26 The photosensitiser was allowed to remain in contact with the aerial hyphae for a period of 10 minutes in order for the fungal elements to be saturated with the blue dye.…”

Section: Preparation Of the Test Organism Inoculummentioning

confidence: 99%

“…low rate of delivery increases inhibition of certain microbes, likely due to improved absorption of the energy. 24 Various concentrations of photosensitisers have been used by different investigators (0-200 μmol/L and 0-90 μg/mL). 25 With a variety of exposure times being utilised by separate investigators.…”

Section: Light Deliverymentioning

confidence: 99%

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In vitro fungicidal effects of methylene blue at 625‐nm

Guffey

Payne

Roegge

2017

Mycoses

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The aim of the study is to confirm the effectiveness of photodynamic therapy (PDT) as a significant inhibitor of Trichophyton rubrum (T. rubrum) and to determine the most appropriate dose and rate of delivery. Trichophyton rubrum is the most common dermatophyte worldwide, responsible for the majority of superficial fungal infections. The traditional treatment of T. rubrum has known adverse effects. An alternative treatment is warranted. Photosensitised T. rubrum specimens were treated with 625-nm light at doses of 3, 12, 24, 40 and 60 J/cm . Colony counts were performed and compared to untreated controls. Doses of 24, 40 and 60 J/cm all produced kill rates of over 94%. A lower rate of delivery (7.80 mW/cm ) was shown to be a greater inhibitor of T. rubrum than a higher rate of delivery (120 mW/cm ). Photodynamic therapy with methylene blue (MB) at 625 nm using a low rate of delivery at doses of 24, 40 and 60 J/cm is an effective inhibitor of T. rubrum. A rate of delivery of 7.80 mW/cm is a significantly greater inhibitor of T. rubrum than a rate of 120 mW/cm when applying 625-nm light in PDT using MB.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Preparation Of the Test Organism Inoculummentioning

confidence: 99%

Section: Light Deliverymentioning

confidence: 99%

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In vitro fungicidal effects of methylene blue at 625‐nm

Guffey

Payne

Roegge

2017

Mycoses

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“…In vitro inhibition of various bacteria using blue light (405–470 nm) has been frequently demonstrated (Guffey and Wilborn ,b; Guffey et al. ,b,c, ,b,c,d,e,f). To our knowledge, only (Guffey et al.…”

Section: Introductionmentioning

confidence: 99%

Inactivation of Salmonella on tainted foods: using blue light to disinfect cucumbers and processed meat products

Guffey

Payne

Motts

et al. 2016

Food Science & Nutrition

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Foodborne illness resulting from infectious organisms occurring in vegetables and processed meat is a serious health concern in the United States. Improved and cost‐effective techniques for disinfection are needed. Visible light in the blue range (405 nm) was administered to processed meat that had been inoculated with Escherichia coli. One application of light energy at doses of 10, 30, 60, and 100 J/cm2 was applied, in vitro. In the case of vegetables contaminated with Salmonella (cucumbers), 464 nm light was used at 6, 12, and 18 J/cm2. In both cases, after 20 hours of incubation, colony‐forming units were counted and compared to controls to determine whether the light energy inhibited growth of E. coli or Salmonella. E. coli – 405 nm light at doses of 30, 60, and 100 J/cm2 were all effective inhibitors of the organism. Kill rates of 75.61 – 96.34% were achieved. Salmonella – 464 nm light at doses of 6, 12, and 18 J/cm2 produced significant inactivation of the organism. Kill rates of 80.23–100% were obtained. Blue light, delivered in the wavelength/dose combinations used in this study is an effective inhibitor of both E. coli and Salmonella on actual foodstuffs. Blue light should be considered as a potentially effective tool in the effort to protect humans from foodborne illnesses.

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Dual wavelength stimulation of polymeric nanoparticles for photothermal therapy

et al. 2016

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Background and Objective Photothermal therapy (PTT) has several applications in the areas of wound healing, pain management, bacterial infection control, and cancer treatment dependent on the temperature that is generated. PTT is often used exclusively with near infrared (NIR) light and most nanoparticles (NP) used for PTT are designed to absorb within one narrow range of wavelengths. We have developed a dual-wavelength photo-thermal therapy by capitalizing on the dual absorption of nanoparticles in the blue and NIR range. Materials and Methods Our lab has previously developed NP based on the semiconducting, conjugated polymer poly-[4,4-bis(2-ethylhexyl)-cyclopenta[2,1-b;3,4-b′]dithiophene-2,6-diyl-alt-2,1,3-benzoselenadiazole-4,7-diyl] (PCPDTBSe). The NP have strong absorption in the blue and NIR regions. In this report, we have explored the heat generated by PCPDTBSe NP using simultaneous delivery of 450 and 800nm light, either independently or together for photothermal ablation of mouse colorectal cancer cells. Results The heat generation studies indicated that the use of either 450 or 800 nm wavelengths at the same fluences produced approximately the same temperature change of deionized water. Fluences of 114.6 and 229.2 J/cm2, utilizing 450 or 800 nm light applied individually resulted in temperatures of 8–47°C above ambient temperature, leading to a 90% reduction in cell viability. Simultaneous stimulation of the PCPDTBSe NP with 450 and 800 nm light effectively doubles the effective power delivered, resulting in temperatures 18–63°C above ambient and 100% photothermal ablation of the colorectal cancer cells. Conclusion The results of this study demonstrate that PCPDTBSe polymer NP can be utilized as effective PTT agents by capitalizing on their dual absorption of both blue and NIR light. Lasers Surg. Med. 48:893–902, 2016.

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The Interaction of Dose and Rate of Delivery Using Visible and Infrared Light to Inhibit Pseudomonas aeruginosa In vitro

Cited by 4 publications

References 19 publications

In vitro fungicidal effects of methylene blue at 625‐nm

In vitro fungicidal effects of methylene blue at 625‐nm

Inactivation of Salmonella on tainted foods: using blue light to disinfect cucumbers and processed meat products

Dual wavelength stimulation of polymeric nanoparticles for photothermal therapy

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