Photophysical and Photochemical Effects of Dye Binding*

Bellin, Judith S.

doi:10.1111/j.1751-1097.1968.tb05883.x

Cited by 35 publications

(5 citation statements)

References 21 publications

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“…The results obtained from the photolysis of crystal violet in deoxygenated solutions and in poly(viny1 alcohol) films are consistent with the view that the same species, the semiquinone radical, is formed in both instances. Contrary to previous reports [5][6][7][8] that triphenylmethane dyes do not undergo photoreduction in solution in the presence of a mild reducing agent such as ascorbic acid except when bound to a high-molecularweight polymer, the present results indicate that photobleaching of crystal violet oxalate solutions does occur via a one-electron reduction of the dye cation to the neutral semiquinone radical, which is quite stable in the absence of oxygen but is rapidly destroyed by light of wavelengths in the region of 400 nm. The reducing agent in this case is probably the oxalate anion, although we have shown that photoreduction also occurs in the presence of ascorbic acid by observing the characteristic ESR spectrum of the oxidized ascorbic acid free radical [29] during illumination of the dye [unpublished data].…”

Section: Resultscontrasting

confidence: 66%

Photoreduction of Crystal Violet in Solution and in Poly(vinyl Alcohol) Films

Leaver

1972

Photochem & Photobiology

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Abstract— The photolysis of crystal violet oxalate has been studied in aqueous and non‐aqueous solutions and in films of poly(viny1 alcohol) at room temperature. Evidence has been obtained from electron‐spin‐resonance, absorption and fluorescence spectroscopy for the formation of the semireduced dye radical, tri‐(p‐dimethylaminophenyl)methyl, both in solution and in the solid state. Electron spin resonance and luminescence spectra of the radical produced by electrolytic reduction of the dye are also reported.

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Section: Resultscontrasting

confidence: 66%

Photoreduction of Crystal Violet in Solution and in Poly(vinyl Alcohol) Films

Leaver

1972

Photochem & Photobiology

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“…Others have also seen this effect [47]. This is a general phenomenon observed with many light sensitive molecules bound to polymers [48].…”

Section: Discussionmentioning

confidence: 57%

A polymeric drug delivery system for the simultaneous delivery of drugs activatable by enzymes and/or light

Krinick¹,

Sun²,

Joyner³

et al. 1994

Journal of Biomaterials Science, Polymer Edition

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Three water soluble copolymers based on N-(2-hydroxypropyl)methacrylamide were prepared. Copolymer I contains adriamycin, a chemotherapeutic agent, attached via enzymatically degradable oligopeptide (glycylphenylalanylleucylglycine; G-F-L-G) side chains. The other two copolymers contained the photosensitizer, meso-chlorin e6 monoethylene diamine disodium salt (Mce6). In Copolymer II, the chlorin is attached via the degradable G-F-L-G sequence, and it was bound by the nondegradable glycyl spacer in Copolymer III. Initially, the copolymers were characterized separately in vitro and in vivo. Combinations of the copolymer bound chemotherapeutic agent and each of the copolymer bound photosensitizers were then assessed for antitumor effect in vivo. Localization/retention studies (A/J mice; Neuro 2A neuroblastoma solid tumor) were performed with the two copolymers containing Mce6 as well as the free drug. Results of these experiments demonstrated a very different tumor uptake profile for the two copolymers. While the free drug was rapidly cleared from tumor tissue, the copolymer containing Mce6 attached via the non-degradable bond was retained for an extended period; drug concentrations in the tumor were high even after 5 days. On the other hand, a high concentration of the copolymer containing Mce6 bound via the degradable sequence was taken up by the tumor, yet its concentration in the tumor was substantially diminished at 48 h after administration. This shows indirect evidence of in vivo cleavage of Mce6 from the copolymer in the lysosomal compartment which is supported by direct evidence of cleavage by cathepsin B (a lysosomal enzyme) in vitro. Antitumor effects were assessed on Neuro 2A neuroblastoma induced in A/J mice for all three copolymers. Photodynamic therapy (PDT) proved the copolymer with Mce6 bound via the degradable oligopeptide sequence to be a more effective photosensitizer in vivo than the other chlorin containing copolymer. The difference in activity was consistent with the results obtained by photophysical analyses in which the free drug had a higher quantum yield of singlet oxygen generation than the polymer bound drug in buffer. The quantum yield of singlet oxygen generation increased with the enzymatic cleavage of the chlorin from the copolymer. Conditions were subsequently determined for which chemotherapy or PDT would show some antitumor effect, yet be incapable of curing tumors. Finally, combination therapy experiments were performed in which the copolymer bound adriamycin was mixed with either of the copolymer bound chlorin compounds and injected intravenously (i.v.) into the tail veins of mice.(ABSTRACT TRUNCATED AT 400 WORDS)

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“…Since pH appeared to be an important factor for MB activity (Spikes and Glad, 1964;Bonneau et al, 1975), the pH dependence should be studied before a definite statement is made. The rather complex behavior of MB in the sensitization activity has also been discussed by Bellin (1968). Our conditions might favor Type I mechanisms for MB, and Type I reactions may not be effective on the membrane.…”

Section: Photodynamic Activitymentioning

confidence: 56%

“…Photodynamic sensitizers may be either free or bound to substrate molecules at the moment they act (Bellin and Grossman, 1965;Bellin, 1968). Recent studies have indicated that when acridine orange (AON is used to sensitize the genetic material in yeast cells, the difference in the structures of sensitizer-DNA complex is rather important Ito, 1976, 1977).…”

Section: Introductionmentioning

confidence: 99%

A SURVEY OF IN VIVO PHOTODYNAMIC ACTIVITY OF XANTHENES, THIAZINES, AND ACRIDINES IN YEAST CELLS

Ito

Kobayashi

1977

Photochem & Photobiology

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Abstract. In view of the recent interest in the possibility of a singlet oxygen mechanism playing an important role in photodynamic action, a number of different types of dyes were surveyed with respect to cell inactivation and induction of genetic changes in yeast cells. These comprise three xanthene dyes, three thiazine dyes, three acridine dyes and ethidium bromide. Rhodamine B in the first group and methylene blue in the second group were inactive under the present conditions. Both were found to be non‐penetrable into the cell. However, since toluidine blue is active, non‐penetrability is not a determining factor in photodynamic action. Ethidium bromide was inactive under the present conditions, even though it was penetrable into the cell. The survey showed that the dye must be bound to DNA in order to be active in the induction of a genetic change (gene conversion). All dyes which were active in either inactivation or induction or both were modified in their effectiveness both by the addition of N‐3 (suppression) and in deuterated medium (enhancement), indicating that the sensitization mechanism involves singlet oxygen. The deuterium effect was generally observable to a lesser extent in the in vivo situation than in vitro, in particular for genetic changes by profiavine and acriflavine in which the sensitizer binds to DNA.

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Photophysical and Photochemical Effects of Dye Binding*

Cited by 35 publications

References 21 publications

Photoreduction of Crystal Violet in Solution and in Poly(vinyl Alcohol) Films

Photoreduction of Crystal Violet in Solution and in Poly(vinyl Alcohol) Films

A polymeric drug delivery system for the simultaneous delivery of drugs activatable by enzymes and/or light

A SURVEY OF IN VIVO PHOTODYNAMIC ACTIVITY OF XANTHENES, THIAZINES, AND ACRIDINES IN YEAST CELLS

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