Photodynamic potentiality of hypocrellin B and its lanthanide complexes

Toffoli, Daniel José; Gomes, Larissa; Vieira, Nilson D.; Courrol, Lilia Coronato

doi:10.1088/1464-4258/10/10/104026

Cited by 10 publications

(6 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The number of bonds between the ions and the molecule depends not only on the nature of the molecule, but also on the nature of the metal ions being used. 1HB:2La +3 structure have the two lanthanum ions bind with the phenolic hydroxyl oxygen and the carbonyl oxygen of HB, and the bridge between these ions is done by Cl -ions [16]. Figure 2b shows the HB:La +3 complex emission spectra under excitation at 460 nm.…”

Section: Optical Properties Of Hb:la 3+ Complexesmentioning

confidence: 99%

“…Hence there is wide interest to improve red absorption [14] and amphiphilicity of hypocrellins. Studies in the literature have shown that the PDT performance of HB can be improved modifying its structure for example complexing it with lanthanum ions [15,16]. To evaluate HB:La 3+ complex activities against in vitro suspension of C. albicans we compare its performance with one of MB.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effectiveness in total reduction of Candida albicans promoted by PDT with hypocrellin B:lanthanum

et al. 2009

View full text Add to dashboard Cite

In this work we described the potentiality of the Hypocrellin B (HB) modified with the presence of lanthanum (La 3+ ) ions, in eliminate Candida albicans in suspension. The results showed that the presence of lanthanum ions promotes a red shift of the HB absorption band and an enhancement in singlet oxygen quantum yield in 32%. Also in this work we obtained that the best molar ration between HB and La concentrations was 1:2. No photobleaching was observed in our experimental conditions. Antimicrobial activity was studied exciting C. albicans suspension with a 460 nm LED and a 660 nm laser both with 330 mW/cm 2 irradiance. Best irradiation time, PS concentration and ROS production profile were determined showing that using 460 nm LED with 10 μM of PS, only 30 s of irradiation time was sufficient to reduce 100 % C. albicans colonies.

show abstract

Section: Optical Properties Of Hb:la 3+ Complexesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effectiveness in total reduction of Candida albicans promoted by PDT with hypocrellin B:lanthanum

et al. 2009

View full text Add to dashboard Cite

show abstract

“…), their tedious synthesis, poor bioavailability, and prolonged patient photosensitivity has limited their application. Thus, there is rising interest in the investigation of alternative structural motifs to develop next-generation PSs, with notable examples including various phenothiazinium derivatives, anthracyclines and anthraquinones (e.g., hypericin and doxorubicin), − xanthenes, , cyanine , and BODIPY dyes, and ruthenium, − rhodium, rhenium, − and lanthanide complexes. − Metal complexes are particularly suitable for this task, as the inclusion of a metal into the PS takes advantage of the heavy atom effect to populate the excited triplet state of the PS ( 3 PS*), which in turn facilitates generation of ROS and, ultimately, cell death.…”

Section: Introductionmentioning

confidence: 99%

Extending the Excitation Wavelength of Potential Photosensitizers via Appendage of a Kinetically Stable Terbium(III) Macrocyclic Complex for Applications in Photodynamic Therapy

et al. 2017

View full text Add to dashboard Cite

The development of viable photodynamic therapy protocols is often hindered by photosensitizers that require high-energy UV irradiation that has limited potential for clinical use due to its low tissue penetration. Herein, we report a strategy for extending the excitation wavelength of potential photosensitizers via the covalent attachment of a terbium(III)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetate complex (DO3A-Tb). The method was systematically demonstrated with a series of polycyclic aromatic hydrocarbons (naphthalene, phenanthrene, anthracene, pyrene, and fluoranthene) to prepare six new complexes (Tb1-Tb6) with bathochromic shifts that extended into the visible region. Determination of their quantum yields for singlet oxygen (O) production at 350 and 420 nm showed significant enhancements from the parent molecule in all cases. Cell viability studies on cervical cancer cells (HeLa) and noncancerous MRC-5 cells showed no measurable cytotoxicity for all complexes prior to light irradiation. However, after irradiation at 420 nm (20 min, 9.27 J cm), Tb3-Tb6 were phototoxic to HeLa cells with IC values between 14.3-32.3 μM. Cell morphological studies and fluorescence microscopy with live/dead cell stains confirmed these findings. In addition, these complexes were highly stable in human blood plasma, with no significant degradation observed after 96 h at 37 °C. This excellent phototoxicity profile and high stability in blood plasma, coupled with the moderately lipophilic nature of the complexes, favorably indicate the potential of DO3A-Tb as a heavy atom-bearing moiety for modification of potential photosensitizers into ideal phototherapeutic drug candidates with longer excitation wavelengths for in vivo application.

show abstract

“…Within this context, this study was divided into two phases: initially, we performed an in vitro assay and tested the viability of the use of aPDT in a clinical isolate of P. aeruginosa strain using hypocrellin B: lanthanum (HB:La +3 ), which has shown to be an successful photosensitizer (15). After that, we developed a burn wound infection model in mice and investigated whether aPDT could reduce P. aeruginosa in the infected site.…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial Photodynamic Therapy on Drug‐resistant Pseudomonas aeruginosa‐induced Infection. An In Vivo Study^†

Hashimoto

Prates

Kato

et al. 2012

Photochem & Photobiology

View full text Add to dashboard Cite

Pseudomonas aeruginosa is considered one of the most important pathogens that represent life-threatening risk in nosocomial environments, mainly in patients with severe burns. Antimicrobial photodynamic therapy (aPDT) has been effective to kill bacteria. The purpose of this study was to develop a burn wound and bloodstream infection model and verify aPDT effects on it. In vitro, we tested two wavelengths (blue and red LEDs) on a clinical isolate of P. aeruginosa strain with resistance to multiple antibiotics using HB:La(+3) as photosensitizer. Verapamil(®) associated to aPDT was also studied. In vivo, P. aeruginosa-infected burned mice were submitted to aPDT. Bacterial counting was performed on local infection and bloodstream. Survival time of animals was also monitored. In this study, aPDT was effective to reduce P. aeruginosa in vitro. In addition, Verapamil(®) assay showed that HB:La(+3) is not recognized by ATP-binding cassete (ABC) efflux pump mechanism. In the in vivo study, aPDT was able to reduce bacterial load in burn wounds, delay bacteremia and keep the bacterial levels in blood 2-3 logs lower compared with an untreated group. Mice survival was increased on 24 h. Thus, this result suggests that aPDT may also be a novel prophylactic treatment in the care of burned patients.

show abstract

Photodynamic potentiality of hypocrellin B and its lanthanide complexes

Cited by 10 publications

References 18 publications

Effectiveness in total reduction of Candida albicans promoted by PDT with hypocrellin B:lanthanum

Effectiveness in total reduction of Candida albicans promoted by PDT with hypocrellin B:lanthanum

Extending the Excitation Wavelength of Potential Photosensitizers via Appendage of a Kinetically Stable Terbium(III) Macrocyclic Complex for Applications in Photodynamic Therapy

Antimicrobial Photodynamic Therapy on Drug‐resistant Pseudomonas aeruginosa‐induced Infection. An In Vivo Study^†

Contact Info

Product

Resources

About

Photodynamic potentiality of hypocrellin B and its lanthanide complexes

Cited by 10 publications

References 18 publications

Effectiveness in total reduction of Candida albicans promoted by PDT with hypocrellin B:lanthanum

Effectiveness in total reduction of Candida albicans promoted by PDT with hypocrellin B:lanthanum

Extending the Excitation Wavelength of Potential Photosensitizers via Appendage of a Kinetically Stable Terbium(III) Macrocyclic Complex for Applications in Photodynamic Therapy

Antimicrobial Photodynamic Therapy on Drug‐resistant Pseudomonas aeruginosa‐induced Infection. An In Vivo Study†

Contact Info

Product

Resources

About

Antimicrobial Photodynamic Therapy on Drug‐resistant Pseudomonas aeruginosa‐induced Infection. An In Vivo Study^†