Consulta: subjectFacets:"Photodynamic therapy"
Registros recuperados: 17
Data/hora: 16/06/2024 10:47:56

Assessment of Leishmania major and Leishmania braziliensis promastigote viability after photodynamic treatment with aluminum phthalocyanine tetrasulfonate (AlPcS4)
Provedor de dados: 80
Autores: JG,Pinto; CP,Soares; J,Mittmann.
Cutaneous leishmaniasis is an infectious disease caused by protozoans of the genus Leishmania, which is transmitted through the bite of hematophagous insects of the genus Lutzomyia. This study aimed at testing in vitro the phototoxic effect of aluminum phthalocyanine tetrasulfonate (AlPcS4) on the viability of Leishmania major and Leishmania braziliensis. Stationary phase promastigote forms were treated with AlPcS4 at 1.0 µM and 10.0 µM and incubated for one hour. Then 659 nm laser was applied at 5 and 10 J/cm². Parasite viability was determined by differential count using the trypan blue dye exclusion method and by monitoring growth curves for nine days. Trypan blue exclusion assay showed a significant reduction of viable parasites compared to controls,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cutaneous leishmaniasis; Antiparasitic agents; Leishmania major; Leishmania braziliensis; AlPcS4; Photodynamic therapy.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992011000300010

An insight on the role of photosensitizer nanocarriers for Photodynamic Therapy
Provedor de dados: 42
Autores: MESQUITA,MARIANA Q.; DIAS,CRISTINA J.; GAMELAS,SARA; FARDILHA,MARGARIDA; NEVES,MARIA G.P.M.S.; FAUSTINO,MARIA AMPARO F.
ABSTRACT Photodynamic therapy (PDT) is a modality of cancer treatment in which tumor cells are destroyed by reactive oxygen species (ROS) produced by photosensitizers following its activation with visible or near infrared light. The PDT success is dependent on different factors namely on the efficiency of the photosensitizer deliver and targeting ability. In this review a special attention will be given to the role of some drug delivery systems to improve the efficiency of tetrapyrrolic photosensitizers to this type of treatment.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photodynamic therapy; Drug delivery; Liposomes; Silica nanoparticles; Gold nanoparticles; Polymeric micelles.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000301101

Evaluation of the photodynamic activity of Xanthene Dyes on Artemia salina described by chemometric approaches
Provedor de dados: 42
Autores: Pellosi,Diogo S.; Batistela,Vagner R.; Souza,Vagner R. de; Scarminio,Ieda S.; Caetano,Wilker; Hioka,Noboru.
The development of drugs for photodynamic therapy (PDT) is an important area of research due to their growing use in medical applications. Therefore, it is important to develop new bioassay methods for PDT photosensitizers that are inexpensive, easy to handle and highly sensitive to environmental conditions. Xanthene dyes (fluorescein, rose bengal B, erythrosine B and eosin Y) with LED light sources were investigated using Artemia salina as a bioindicator of photodynamic activity. In this study, three factors were investigated: (i) photosensitizers concentration, (ii) the LED irradiation time and (iii) the waiting time between the addition of the photosensitizers and the beginning of the irradiation. To analyze the photo-killing of A. salina, it was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Artemia salina; Factorial design; Photodynamic therapy; Bioassay; Xanthenes.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000401267

Ultrastructural effects of two phthalocyanines in CHO-K1 and HeLa cells after laser irradiation
Provedor de dados: 47
Autores: de CastroPazos,Marcelo; Pacheco-Soares,Cristina; Soares da Silva,Newton; DaMatta,Renato Augusto; Pacheco,Marcos Tadeu T.
The effects of Photodynamic Therapy using 2nd generation photosensitizers have been widely investigated aiming clinical application treatment of solid neoplasms. In this work, ultrastructure changes caused by the action of two 2nd generation photosensitizers and laser irradiation on CHO-K1 and HeLa (neoplastic) cells were analyzed by transmission electron microscopy. Aluminum phthalocyanine chloride, aluminum phthalocyanine tetrasulfonate chloride and radiation from a semiconductor laser at a fluency of 0.5 J/cm² (Power=26mW; l=670nm) were used. The results showed induction of apoptosis. Such alterations where observed in HeLa but not in CHO-K1 cells after Aluminum phthalocyanine tetrasulfonate chloride (AlPcS4) photodynamic treatment. The Aluminum...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photodynamic therapy; Phthalocyanines; Laser; Cell death; Ultrastructure.
Ano: 2003
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452003000300001

Protein microarray for complex apoptosis monitoring of dysplastic oral keratinocytes in experimental photodynamic therapy
Provedor de dados: 48
Autores: Matei,Clara; Tampa,Mircea; Caruntu,Constantin; Ion,Rodica-Mariana; Georgescu,Simona-Roxana; Dumitrascu,Georgiana Roxana; Constantin,Carolina; Neagu,Monica.
BACKGROUND: Photodynamic therapy is an alternative treatment of muco-cutaneous tumors that uses a light source able to photoactivate a chemical compound that acts as a photosensitizer. The phthalocyanines append to a wide chemical class that encompasses a large range of compounds; out of them aluminium-substituted disulphonated phthalocyanine possesses a good photosensitizing potential. RESULTS: The destructive effects of PDT with aluminium-substituted disulphonated phthalocyanine are achieved by induction of apoptosis in tumoral cells as assessed by flow cytometry analysis. Using protein microarray we evaluate the possible molecular pathways by which photodynamic therapy activates apoptosis in dysplastic oral keratinocytes cells, leading to the tumoral...
Tipo: Journal article
Palavras-chave: Aluminum di-sulphonated phthalocyanine; DOK cells; Photodynamic therapy; Protein microarray.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602014000100033

Enhanced response of the fricke solution doped with hematoporphyrin under X-rays irradiation
Provedor de dados: 52
Autores: Austerlitz,Carlos; Souza,Vivianne Lúcia Bormann de; Campos,Diana Maria Tavares; Kurachi,Cristina; Bagnato,Vanderley; Sibata,Cláudio.
The vials filled with Fricke solutions were doped with increasing concentrations of Photogem®, used in photodynamic therapy. These vials were then irradiated with low-energy X-rays with doses ranging from 5 to 20 Gy. The conventional Fricke solution was also irradiated with the same doses. The concentration of ferric ions for the Fricke and doped-Fricke irradiated solutions were measured in a spectrophotometer at 220 to 340 nm. The results showed that there was an enhancement in the response of the doped-Fricke solution, which was proportional to the concentration of the photosensitizer. The use of such procedure for studying the radiosensitizing property of photosensitizers based on the production of free radicals is also discussed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photodynamic therapy; Hematoporphyrin; Fricke dosimeter; Free radicals.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000200006

The inhibitory effect of photodynamic therapy and of an anti-VCAM-1 monoclonal antibody on the in vivo growth of C6 glioma xenografts
Provedor de dados: 56
Autores: Zhan,Qi; Yue,Wu; Shaoshan,Hu.
We investigated the effect of photodynamic therapy (PDT) and of an anti-vascular cell adhesion molecule-1 (VCAM-1) monoclonal antibody on the in vivo growth of C6 glioma. Seven days after inoculation with C6 cells, adult male Wistar rats weighing 280-300 g with MRI-confirmed glioma were randomly assigned to 4 groups (N = 15 per group): PDT + VCAM-1 antibody group; PDT group; VCAM-1 antibody group; control group. Eight days after inoculation, hematoporphyrin monomethyl ether (HMME) was administered as a photosensitizer and PDT was performed at 630 nm (illumination intensity: 360 J/cm²) for 10 min. VCAM-1 antibody (50 µg/mL) was then administered (0.5 mL) through the tail vein every other day from day 8 to day 16. At day 21, 5 rats in each group were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: C6 glioma cells; Photodynamic therapy; Hematoporphyrin monomethyl ether; Anti-VCAM-1 monoclonal antibody; Apoptosis.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000500016

Liposomal photosensitizers: potential platforms for anticancer photodynamic therapy
Provedor de dados: 56
Autores: Muehlmann,L.A.; Joanitti,G.A.; Silva,J.R.; Longo,J.P.F.; Azevedo,R.B.
Photodynamic therapy is a well-established and clinically approved treatment for several types of cancer. Antineoplastic photodynamic therapy is based on photosensitizers, i.e., drugs that absorb photons translating light energy into a chemical potential that damages tumor tissues. Despite the encouraging clinical results with the approved photosensitizers available today, the prolonged skin phototoxicity, poor selectivity for diseased tissues, hydrophobic nature, and extended retention in the host organism shown by these drugs have stimulated researchers to develop new formulations for photodynamic therapy. In this context, due to their amphiphilic characteristic (compatibility with both hydrophobic and hydrophilic substances), liposomes have proven to be...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photodynamic therapy; Liposome; Antineoplastic therapy; Cancer; Photosensitizer.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000800001

Effect of photodynamic therapy on the extracellular matrix and associated components
Provedor de dados: 56
Autores: Pazos,M.d.C.; Nader,H.B.
In many countries, photodynamic therapy (PDT) has been recognized as a standard treatment for malignant conditions (for example, esophageal and lung cancers) and non-malignant ones such as age-related macular degeneration and actinic keratoses. The administration of a non-toxic photosensitizer, its selective retention in highly proliferating cells and the later activation of this molecule by light to form reactive oxygen species that cause cell death is the principle of PDT. Three important mechanisms are responsible for the PDT effectiveness: a) direct tumor cell kill; b) damage of the tumor vasculature; c) post-treatment immunological response associated with the leukocyte stimulation and release of many inflammatory mediators like cytokines, growth...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photodynamic therapy; Extracellular matrix; Adhesion; Chemical mediators; Matrix metalloproteinases.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000800002

Nitric oxide release from the S-nitrosothiol zinc phthalocyanine complex by flash photolysis
Provedor de dados: 56
Autores: Rotta,J.C.G.; Lunardi,C.N.; Tedesco,A.C.
The photogeneration of nitric oxide (NO) using laser flash photolysis was investigated for S-nitroso-glutathione (GSNO) and S-nitroso-N-acetylcysteine (NacySNO) at pH 6.4 (PBS/HCl) and 7.4 (PBS). Irradiation of S-nitrosothiol with light (lambda = 355 nm followed by absorption spectroscopy) resulted in the homolytic decomposition of NacySNO and GSNO to generate radicals (GS· and NacyS·) and NO. The release of NO from donor compounds measured with an ISO-Nometer apparatus was larger at pH 7.4 than pH 6.4. NacySNO was also incorporated into dipalmitoyl-phosphatidylcholine liposomes in the presence and absence of zinc phthalocyanine (ZnPC), a well-known photosensitizer useful for photodynamic therapy. Liposomes are usually used as carriers for hydrophobic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: S-nitrosothiols; Nitric oxide; Zinc phthalocyanine; Liposomes; Photodynamic therapy.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000500005

Photodynamic antimicrobial chemotherapy (PACT) for the treatment of malaria, leishmaniasis and trypanosomiasis
Provedor de dados: 56
Autores: Baptista,M.S.; Wainwright,M.
A photodynamic effect occurs when photosensitiser molecules absorb light and dissipate the absorbed energy by transferring it to biological acceptors (usually oxygen), generating an excess of reactive species that are able to force cells into death pathways. Several tropical diseases present physiopathological aspects that are accessible to the application of a photosensitiser and local illumination. In addition, disease may be transmitted through infected blood donations, and many of the aetiological agents associated with tropical diseases have been shown to be susceptible to the photodynamic approach. However, there has been no systematic investigation of the application of photoantimicrobial agents in the various presentations, whether to human disease...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tropical diseases; Photodynamic therapy; Singlet oxygen; Photosensitisers; Leishmania; Chagas’ disease.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000100001

Possible in vivo mechanisms involved in photodynamic therapy using tetrapyrrolic macrocycles
Provedor de dados: 56
Autores: Filip,A.G.; Clichici,S.; Daicoviciu,D.; Ion,R.M.; Tatomir,C.; Rogojan,L.; Opris,I.; Mocan,T.; Olteanu,D.; Muresan,A.
Photodynamic therapy (PDT) mediated by oxidative stress causes direct tumor cell damage as well as microvascular injury. To improve this treatment new photosensitizers are being synthesized and tested. We evaluated the effects of PDT with 5,10,15,20-tetrakis(4-methoxyphenyl)-porphyrin (TMPP) and its zinc complex (ZnTMPP) on tumor levels of malondialdehyde (MDA), reduced glutathione (GSH) and cytokines, and on the activity of caspase-3 and metalloproteases (MMP-2 and -9) and attempted to correlate them with the histological alterations of tumors in 3-month-old male Wistar rats, 180 ± 20 g, bearing Walker 256 carcinosarcoma. Rats were randomly divided into five groups: group 1, ZnTMPP+irradiation (IR) 10 mg/kg body weight; group 2, TMPP+IR 10 mg/kg body...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photodynamic therapy; Oxidative stress; Apoptosis; Tetrapyrrolic macrocycles; Cytokines.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000100008

The effect of porphyrins on normal and transformed mouse cell lines in the presence of visible light
Provedor de dados: 56
Autores: Tita,S.P.S; Perussi,J.R.
Photodynamic therapy consists of the uptake of a photosensitizing dye, often a porphyrin, by tumor tissue and subsequent irradiation of the tumor with visible light of an appropriate wavelength matched to the absorption spectrum of the photosensitizing dye. This class of molecules produces reactive oxygen species when activated by light, resulting in a direct or indirect cytotoxic effect on the target cells. Photodynamic therapy has been used in the treatment of cancer but the technology has a potential for the treatment of several disease conditions mainly because of its selectivity. However, it is not clear why the porphyrins are retained preferentially by abnormal tissue. This paper describes a study of the effect of the association of porphyrin and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Water-soluble porphyrins; Mouse fibroblast lines A31 and B61; Photodynamic therapy; Visible light.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001001000014

Enhanced anti-tumor efficacy of 5-aminolevulinic acid-gold nanoparticles-mediated photodynamic therapy in cutaneous squamous cell carcinoma cells
Provedor de dados: 56
Autores: Chi,Yu-fei; Qin,Jing-jing; Li,Zhi; Ge,Qin; Zeng,Wei-hui.
The objective of this study was to investigate whether the conjugation of gold nanoparticles (GNPs) to 5-aminolevulinic acid (5-ALA) could enhance the anti-tumor efficiency of photodynamic therapy (PDT) in epidermoid carcinoma cells. The mRNA and protein expression levels were determined by quantitative real-time PCR and western blot, respectively. Cell viability, apoptosis, invasion, and migration were determined by MTT assay, flow cytometry, transwell invasion assay, and migration assay, respectively. Singlet oxygen generation was detected by the singlet oxygen sensor green reagent assay. Our results showed that PDT with 5-ALA and GNPs-conjugated 5-ALA (5-ALA-GNPs) significantly suppressed cell viability, increased cell apoptosis and singlet oxygen...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photodynamic therapy; 5-ALA-GNPs; Cell viability; Cell apoptosis; Cell invasion and migration; Cutaneous squamous cell carcinoma.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2020000500608

Fluorometric quantification of protoporphyrin IX in biological skin samples from in vitro penetration/permeation studies
Provedor de dados: 60
Autores: Rossetti,Fábia Cristina; Depieri,Lívia Vieira; Tedesco,Antônio Cláudio; Bentley,Maria Vitória Lopes Badra.
A fluorometric analytical method was developed for quantification of protoporphyrin IX (PpIX) in skin samples and receptor phase solution after in vitro cutaneous penetration/permeation studies. Analytical conditions used were: excitation and emission wavelengths: 400 nm and 632 nm; bandwidth: 0.5 nm; excitation and emission slits: 10/10. PpIX was recovered from two different layers of skin, the stratum corneum (SC) and the epidermis plus dermis ([E+D]), by vortex homogenization, probe and bath sonication, using DMSO as an extraction solvent. The detection and quantification limits were 0.002 and 0.005 μg/mL, respectively. The assay was linear from 0.005 - 0.5 μg/mL. The within-day and between-day assay precision and accuracy in DMSO and receptor phase...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fluorometric quantification; Protoporphyrin IX/determination; Photodynamic therapy; Porcine skin; Cutaneous penetration/in vitro study; Cutaneous permeation/in vitro study.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502010000400017

5-Aminolevulinic acid photoactivated over planktonic and biofilm forms of Enterococcus faecalis as a pharmacological therapy alternative
Provedor de dados: 60
Autores: Beltran-Leal,Adriana; Muñoz-Ruiz,Abraham; Esparza-Villalpando,Vicente; Castro,Yolanda; Pozos-Guillen,Amaury; Flores,Héctor.
The purpose of the study was to evaluate the antibacterial effect of protoporphyrin IX (PpIX) generated by the exogenous administration of 5-aminolevulinic acid or δ-ALA and activated with an argon laser over a planktonic and biofilm of Enterococcus faecalis (E. faecalis) as a pharmacological therapy alternative. A planktonic strain of E. faecalis was cultured with a solution of ∂-ALA (40 µg/mL)-thioglycolate solution for 13 min, and a biofilm of E. faecalis was cultured in a δ-ALA (80 µg/mL)-thioglycolate solution for 13 min. Then, both were irradiated with an argon laser. Finally, the antibacterial effect was evaluated by counting the CFU in planktonic form, and a LIVE/DEAD viability cell test. The production and accumulation of PpIX from exogenously...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biofilm; Photodynamic therapy; 5-aminolevulinic acid.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502020000100572

Influence of ceramide 2 on in vitro skin permeation and retention of 5-ALA and its ester derivatives, for Photodynamic Therapy
Provedor de dados: 60
Autores: Pierre,Maria Bernadete Riemma; Lopez,Renata Fonseca Vianna; Bentley,Maria Vitória Lopes Badra.
Photodynamic therapy (PDT) based on topical 5-aminolevulinic acid (5-ALA), an endogenous precursor of protoporphyrin, is an interesting approach for the treatment of skin cancer. However, 5-ALA is a hydrophilic molecule and such a characteristic limits its appropriate cutaneous penetration and retention. In this way, more lipophilic molecules, such as esterified 5-ALA derivatives, have been under investigation in order to improve the skin penetration of this molecule. Drug formulation can also alter 5-ALA skin penetration. Therefore, the aim of this work was to study the influence of ceramide 2 - the main lipid of the SC- on the cutaneous delivery of 5-ALA and its ester derivatives in vitro, using Franz diffusion cell. The skin permeation of all studied...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 5-aminolevulinic acid; Ceramide 2; In vitro/Skin permeation; In vitro/Skin retention; Photodynamic therapy.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502009000100013