Methylene blue mediated photodynamic therapy in experimental colorectal tumors in mice

Orth, Klaus; Beck, Gerd C.; Genze, Felicitas; Rück, Angelika

doi:10.1016/s1011-1344(00)00105-6

Cited by 124 publications

(80 citation statements)

References 35 publications

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“…The high quantum yield of 1 O 2 generation (Φ Δ ~ 0.5) by MB, via excitation in the therapeutic window (600-900 nm), coupled with its low toxicity, makes MB a promising candidate for PDT [7][8][9][10]. However, the clinical use of MB has been hampered by its propensity for rapid chemical alteration when systemically applied: MB in the biological environment is usually converted by accepting electrons from NADH/NADPH, and unfortunately, the formed colorless leukomethylene blue (LMB) has negligible photodynamic activity [11][12][13]. Recent studies suggested the presence of a transmembrane thiazine dye reductase at the cell surface as the initial factor for MB reduction [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Encapsulation of methylene blue in polyacrylamide nanoparticle platforms protects its photodynamic effectiveness

Tang

Park

et al. 2008

Biochemical and Biophysical Research Communications

107

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The ability to prevent methylene blue (MB), a photosensitizer, from being reduced by plasma reductases will greatly improve its efficacy in photodynamic therapy (PDT) applications. We have developed a delivery approach for PDT by encapsulating MB using nanoparticle platforms (NPs). The 30-nm polyacrylamide-based NPs provide protection for the embedded MB against reduction by diaphorase enzymes. Furthermore, our data shows the matrix-protected MB efficiently induces photodynamic damage to tumor cells. The unprecedented results demonstrate the significant in vitro photodynamic effectiveness of MB when encapsulated within NPs, which promises to open new opportunities for MB in its in vivo and clinical studies.

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Section: Introductionmentioning

confidence: 99%

Encapsulation of methylene blue in polyacrylamide nanoparticle platforms protects its photodynamic effectiveness

Tang

Park

et al. 2008

Biochemical and Biophysical Research Communications

107

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“…Possessing electron-donating substituents this class of molecules maximally absorb light within the biological therapeutic window (600-800 nm). One of the most evolving application of methylene blue and its derivatives has been as photosensitizing agents in photodynamic therapy [25,26]. Due to their properties, PTZ derivatives are interesting candidates for obtaining new materials (e.g.…”

Section: Introductionmentioning

confidence: 99%

A first-principles study of Ï€-conjugated thiol phenothiazine derivatives adsorbed on Au(111) surface

2009

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Abstract:We present an extensive theoretical study of a series of phenothiazine derivatives adsorbed on Au(111). A series of experimentally accessible quantities are calculated (ultra-violet photoemission spectra, scanning tunneling microscopy images). All simulations were performed by using DFT techniques and LCAO expansion of the molecular orbitals. The microscopic picture established in this work provides a deeper understanding of the interfacial processes that govern the working principle of single-molecule electronics and organic electronic devices. PACS

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“…The weak pharmaceutical effect of MB (26,43,47) results in part from poor penetration of MB into the cellular compartment of tumors and its inactivation via reduction of the cation to the neutral leukomethylene blue (LMB). The latter results in almost complete loss of photodynamic activity (28,46,47).…”

mentioning

confidence: 99%

Eradication of Bacteria in Suspension and Biofilms Using Methylene Blue-Loaded Dynamic Nanoplatforms

Wu¹,

Tang

et al. 2009

Antimicrob Agents Chemother

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The bacterial killing efficiency of a dynamic nanoplatform (DNP) was evaluated. The polyacrylamide (PAA) hydrogel matrix of the DNP was loaded with methylene blue (MB) and was previously applied successfully to killing rat C6 glioma tumor cells in culture. This series of experiments is aimed at determining the suitability of this nanoplatform for elimination of bacterial infections. Suspended cultures of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter sp. were exposed to activated (ϳ650-nm laser light) MB-PAA-DNPs. The killing efficiency of nanoparticle mass concentration, light irradiance and fluence, and dark incubation time was determined on each of the bacterial species. Moreover, the ability of activated MB-PAA-DNPs to inhibit biofilm growth and eradicate and disperse preformed biofilms, preformed on glass and polystyrene surfaces, was demonstrated. The data revealed that activated MB-PAA-DNPs eradicated all species of bacteria examined. Also, encapsulation of MB into the PAA-DNP matrix significantly diminished the observed dark toxicity of free dye. The photobactericidal efficacy of MB-PAA-DNP was found to be higher for gram-positive bacteria than for gram-negative bacteria. In addition, activated MB-PAA-DNP can inhibit biofilm growth and eradicate almost all of the early-age biofilms that are formed by all of the bacteria examined.

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Methylene blue mediated photodynamic therapy in experimental colorectal tumors in mice

Cited by 124 publications

References 35 publications

Encapsulation of methylene blue in polyacrylamide nanoparticle platforms protects its photodynamic effectiveness

Encapsulation of methylene blue in polyacrylamide nanoparticle platforms protects its photodynamic effectiveness

A first-principles study of Ï€-conjugated thiol phenothiazine derivatives adsorbed on Au(111) surface

Eradication of Bacteria in Suspension and Biofilms Using Methylene Blue-Loaded Dynamic Nanoplatforms

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