In Vitro Photodynamic Activity of a Series of Methylene Blue Analogues¶

  title={In Vitro Photodynamic Activity of a Series of Methylene Blue Analogues¶},
  author={Kirste J. Mellish and Russell D. Cox and David I. Vernon and John Griffiths and Stanley B. Brown},
Abstract We have synthesized a series of symmetrical phenothiazines in which the methyl groups of methylene blue have been substituted by longer alkyl chains. Intrinsic photosensitizing ability was not altered by increasing the chain length. However, in vitro phototoxicity after 2 h incubation of RIF-1 murine fibrosarcoma cells followed the order n-propyl > n-pentyl > n-butyl > n-hexyl > ethyl > methyl, with ethyl and n-propyl analogues being 14- and 130-fold more phototoxic than methylene blue… 

Synthesis and DNA interactions of a bis-phenothiazinium photosensitizer.

Analysis of photocleavage products at nucleotide resolution revealed that direct strand breaks and alkaline-labile lesions occurred predominantly at guanine bases, and while compound 3 and MB were both shown to stabilize duplex DNA, the DeltaTm values of calf thymus (CT) and C. perfringens DNAs were approximately three fold higher in the presence of compound 3.

with Basic Side Chains

Derivatives of the standard cationic photosensitiser, methylene blue, were synthesised, having extra amino (basic) functionality in the auxochromic side-chain, such that ionisation of the amino groups in situ, via protonation, provided a range of charge distribution and degree of charge across the molecular framework.

Design and Synthesis of Novel Phenothiazinium Photosensitiser Derivatives

A high-yielding approach towards N-(2-aminoethyl)-Azure B has been established and extended towards the preparation of a functionalized peptide-dye synthetic precursor; Boc-protected

Phenothiazinium photoantimicrobials with basic side chains.

Photodynamic Efficiency of Xanthene Dyes and Their Phototoxicity against a Carcinoma Cell Line: A Computational and Experimental Study

It was observed that the halogen substituents increased the hydrophilicity and photodynamic activity, consistent with the cytotoxic experiments, and the lowest dipole moment and highest molecular volume of RB corroborate with its highest hydrophobicity due to heavy atom substituent like halogens, while the halogens did not affect expressively the electronic features at all.

Hydrogen Bond Acceptors and Additional Cationic Charges in Methylene Blue Derivatives: Photophysics and Antimicrobial Efficiency

In suspensions with both, Gram-positive and Gram-negative bacteria, some derivatives were highly active upon illumination to inactivate S. aureus and E. coli up to 7 log10 steps (99.99999%) without inherent toxicities in the nonirradiated state.

Photodynamic Characterization and In Vitro Application of Methylene Blue-containing Nanoparticle Platforms¶

The concept of the drug-delivering nanoparticles has been extended to a new type of dynamic nanoplatform (DNP) that only delivers 1O2 that could also be used as a targeted multifunctional platform for combined diagnostics and therapy of cancer.



Photosensitization, uptake, and retention of phenoxazine Nile blue derivatives in human bladder carcinoma cells.

The correspondence between 1O2 yield and photosensitizing potency, together with results showing enhanced photocytotoxicity in the presence of D2O and reduced photocyTotoxicity under hypoxic conditions, strongly suggests that the generation of 1O1 is a major mechanism mediating the photocyfiltration effect.

Photosensitizing effects of the tricyclic heteroaromatic cationic dyes pyronin Y and toluidine blue O (tolonium chloride).

The data suggest that PY and TB, like other mitochondrial dyes, may have a selective antitumor photosensitizing activity.

Uptake and photoeffectiveness of two thiazines in HeLa cells.

For both sensitizers, the survival of HeLa cells was dependent on the incubation time, as well as the light dose, for a given concentration (10(-5) M).

Novel photodynamic effects of a benzophenothiazine on two different murine sarcomas.

It is suggested that the redox properties of the dye coupled with the differing metabolic states of the tumor and skin, which increase the amount of photoactive, oxidized dye present in the tumors and decrease it in the skin, are responsible for this unique differential PDT effect.

Phenothiazine Photosensitizers. III. Activity of Methylene Blue Derivatives against Pigmented Melanoma Cell Lines

The cytotoxicity and photocytotoxicity of methylene blue and several of its derivatives against two pigmented melanoma cell lines were investigated in culture and there was no direct correlation with toxicity.

Lysosomal localization and mechanism of uptake of Nile blue photosensitizers in tumor cells.

Results of the present study suggest that the lysosomes may be an intracellular target for photodynamic killing of tumor cells mediated by Nile blue photosensitizers and that lysOSomotropic photosensitization may be a strategy for effective and selective destruction of tumors cells.

Apoptosis induction by different pathways with methylene blue derivative and light from mitochondrial sites in V79 cells

It is shown that MBD is localized in mitochondria and not in lysosomes, endoplasmic reticulum or Golgi apparatus of V79 Chinese hamster fibroblasts, and light induced cell death by apoptosis via 2 different pathways, one rapid and one delayed, depending on the amount of dye in the cells.

Photochemotherapy of experimental colonic tumours with intra-tumorally applied methylene blue

Dark toxicity of MB+ (1%) could be well demonstrated by sufficient sensitiser incorporation without irradiation, which led to a stationary tumour volume up to 3 weeks after injection, which is a potential treatment for inducing necrosis in vivo.