Methylene blue,curcumin and ion pairing nanoparticles effects on photodynamic therapy of MDA-MB-231 breast cancer cell

PurposeThe aim of current study was to use methylene blue-curcumin ion pair nanoparticles and single dyes as photosensitizer for comparison of photodynamic therapy (PDT) efficacy on MDA-MB-231 cancer cells, also various light sources effect on activation of photosensitizer (PS) was considered.MethodIon pair nanoparticles were synthesized using opposite charge ions precipitation and lyophilized. The PDT experiments were designed and the effect of PSs and light sources (Red LED (630 nm; power density: 30 mW cm⁻²) and blue LED (465 nm; power density: 34 mW cm⁻²)) on the human breast cancer cell line were examined. The effect of PS concentration (0–75 μg. mL⁻¹), incubation time, irradiation time and light sources, and priority in irradiation of blue or red lights were determined.ResultsThe results show that the ion pairing of methylene blue and curcumin enhance the photodynamic activity of both dyes and the cytotoxicity of ion pair nanoparticles on the MDA-231 breast cancer cell line. Blue and red LED light sources were used for photo activation of photosensitizers. The results demonstrated that both dyes can activate using red light LED better than blue light LED for singlet oxygen producing.ConclusionNano scale ion pair precipitating of methylene blue-curcumin enhanced the cell penetrating and subsequently cytotoxicity of both dyes together.     

Photodynamic therapy using methylene blue in lung adenocarcinoma xenograft and hamster cheek pouch induced squamous cell carcinoma

BackgroundPhotodynamic therapy (PDT) is used to treat early proximal bronchial cancer during a flexible bronchoscopy. The technique relies on the excitation of a photosensitizer by an appropriate wavelength, which is delivered into the bronchus in close contact with the tumor.ObjectiveTo assess methylene blue (MB) as a PDT agent for the treatment of respiratory tract cancer in animal models.MethodsMB-induced PDT was performed on 7 subcutaneous NCI-H460 lung adenocarcinoma xenografts in nude mice and 9 induced squamous cell cancer in the hamster cheek pouch model. In mice, PDT was carried out on right-sided tumors after intratumoral injection of methylene blue 1% (w/v) and illumination at 630 nm at 200 J/cm (Diomed PDT 630), with the left tumor used as control (illumination alone or MB alone). The tumoral volume was assessed before and 15 days after PDT.ResultsFourteen xenografts were treated in mice, including seven treated with MB-PDT, producing a 52% mean tumor volume regression (1568 mm³ vs. 544 mm³) compared to seven control cases in which tumor volume increased (p = 0.007; Mann-Whitney test). Nine cheek pouch induced carcinomas were treated in the hamster group, with a mean volume decrease of 85.8% (from 44.8% to 100%) (initial mean volume = 210 mm³ vs. post PDT mean volume = 97 mm³). Histology analysis showed 4/9 complete responses.ConclusionIntratumoral MB appears efficient as PDT agent for cancer treatment in animal models. Further studies are needed to assess the safety and efficacy of MB-associated PDT for the treatment of lung cancer in humans.     

Effects of photodynamic therapy with talaporfin sodium on squamous cell carcinoma and sarcoma cells

BackgroundPhotodynamic therapy (PDT) uses a photosensitizer and light to destroy abnormal cells. Talaporfin sodium (NPe6) is a second-generation photosensitizer.MethodsWe evaluated the toxic effects of different combinations of laser and NPe6 doses on squamous cell carcinoma (KLN205) and sarcoma (Meth A) cell lines. The cells were incubated with 0, 5, 10, or 30 μg/mL NPe6 for 24 h. The cells were then irradiated with 0, 5, 15, or 30 mW/cm² of laser power, and 0, 1, 5, 10, or 20 J/cm² of laser energy. Cell viability was evaluated after 24 h. We also evaluated the cytotoxic effects of continuous wave or square-wave modulated laser irradiations (2, 5, or 10 Hz, 50% duty) on Meth A cells.ResultsThe median lethal doses of NPe6 against the KLN205 and Meth A cells after treatment at a fluence rate of 15 mW/cm² and a light dose of 20 J/cm² were 18.6 and 5.0 μg/mL, respectively. Meth A cells were more sensitive to PDT than KLN205 cells. There was no significant difference between the effects of continuous wave and square-wave modulated lasers on Meth A cell viability.ConclusionsNPe6 PDT induced cell death in a dose-dependent manner in KLN205 and Meth A cells. More work is required to evaluate the cytotoxic effects of square-wave modulated laser therapy at low light doses.     

Photodynamic therapy using Photofrin and excimer dye laser treatment for superficial oral squamous cell carcinomas with long-term follow up

ObjectivesPhotodynamic therapy (PDT) is a very effective treatment for superficial malignancies that does not result in loss of normal tissue. Here, we report successful PDT treatment of superficial oral cancers and its clinical outcome with long-term follow up.Materials and methodsThirty-four superficial oral squamous cell carcinomas were treated with PDT, and the effects were evaluated. Each patient received Photofrin (2 mg/kg) intravenously 48 h prior to light irradiation. Photoradiation was performed at doses of 100–150 J/cm² using a 630-nm wavelength excimer dye laser.ResultsSix months after PDT, 30 patients (88.2%) showed complete responses while 9 patients (26.5%) had local relapses during long-term follow-up. The 5-year overall survival, disease-specific survival, and disease-free survival rates were 76.5%, 84.6%, and 63.3%, respectively. Lesions with red patches had a significantly higher recurrence rate than lesions with white patches. Accurate evaluation of the extent of lesions and appropriate photoradiation were important in improving outcomes. Adverse events observed included sunburn and sequestrum formation of alveolar bone. No abnormal laboratory values or systemic complications were observed.ConclusionPDT using Photofrin as the photosensitizer is an effective treatment modality for superficial oral carcinomas, with excellent healing and minimal side effects.     

Sub-additive effects of photodynamic therapy combined with erlotinib for the treatment of epidermoid carcinoma: An in vitro study

BackgroundPhotodynamic therapy (PDT) is an antitumour treatment that employs the combination of a photosensitive compound, oxygen and visible light. To improve the antitumour activity of PDT, the present study used the strategy of combining PDT with erlotinib (ERL), a drug frequently used in the treatment of epidermoid carcinoma.MethodsAn MTT cell viability assay was used to evaluate the cytotoxicity of PDT combined with ERL on A431 epidermoid carcinoma cells in vitro. This study evaluated the cytotoxicity of the following treatments: red laser irradiation (660 nm) at different power densities (1.25–180 J/cm²), the photosensitizer methylene blue (MB) at concentrations of 0.39–100 μM, PDT (12.5 μM MB and laser power densities from 1.25 to 180 J/cm²), and PDT (12.5 μM MB and a laser density of 120 J/cm²) plus ERL (1 μM).ResultsThe laser power densities that were tested showed no cytotoxicity in A431 cells. MB showed a dose-dependent cytotoxicity. In PDT, an increase in the dose of light resulted in an increase in the cytotoxicity of MB. In addition, there was a sub-additive effect between PDT and ERL compared to the effect of each therapy alone.ConclusionsThe sub-additive effect between PDT and ERL suggests that their combination may be an important strategy in the treatment of epidermoid carcinoma.     

Photodynamic therapeutic efficacy of symmetrical diiodinated squaraine in in vivo skin cancer models

BackgroundPhotodynamic therapy (PDT) has clinical approval for use as a minimally invasive therapeutic procedure that is able to exert selective cytotoxic activity toward malignant cells. The dye selected for our study, symmetrical diiodinated squaraine, is one of the newly developed photosensitizers. The study is designed to determine the efficacy of PDT mediated by symmetrical diiodinated squaraine in skin tumor induced Swiss albino mice.MethodsSkin tumor was induced in mice with dimethyl benzanthracene (DMBA) and croton oil. After squaraine administration to the tumor mice, photodynamic treatment of tumors was performed using a 1000 W halogen lamp corresponding to the light dose of 100 J/cm². The mice were euthanized and skin flaps and tumor tissues from the back of mice were excised for biochemical studies. The biochemical parameters analyzed include some relevant tumor markers for epithelial tissues, inflammatory markers and markers of apoptosis. The gene expression studies were done by RT-PCR.ResultsAfter two weeks of the treatment, there was significant inflammation. However at 90 days after PDT, the parameters reverted to near-normal values. All marker parameters of tumor progression brought back to normal levels by PDT. Increased caspase-3 activity in PDT treated group shows that cell death might have occurred by apoptosis. The gene expression profile confirms the results.ConclusionsThe results of the whole study show the therapeutic efficacy and apoptosis mediated tumor destruction by squaraine PDT.     

Endobronchial photodynamic therapy under fluorescence control: Photodynamic theranostics

BackgroundPhotodynamic therapy (PDT) has several advantages. However, one of the disadvantages is its inability to be individualized according to biological characteristics of malignant tumors. The objective of this study was to investigate a strategy for individualized endobronchial PDT in the treatment of centrally located non-small cell lung cancer.MethodsNew approach suggests taking fluorescence-based measurements of chlorine E6 photosensitizer (PS) accumulation in the malignant tumor tissue, and assess PS consumption rate during PDT. Two randomized groups of 45 patients took part in the comparative study of standard PDT procedure, 662 nm, pulse-periodic mode, therapeutic light (reference group – RG) versus the investigated individualized approach under fluorescence control after irradiation with violet light, 408 nm, diagnostic light (study group – SG). The PDT-treatment parameters and results of follow-up bronchoscopy were compared between the groups.Results43 (96%) of 45 patients in SG demonstrated intense fluorescence in the area of the tracheal/bronchial tumor stenosis. 4 (9%) of 45 patients (SG) demonstrated fluorescence of mucosa areas distant from the main tumor lesion after violet light irradiation. Mean fluence during the whole PDT procedure was 95 ± 20 J/cm² (range 60–130 J/cm²), which was significantly lower than in RG (p = 0.01). Total exposure time was significantly lower in SG (365 ± 65 s), compared with RG (690 ± 65 s), P = 0.001. According to the follow-up bronchoscopy the difference in the PDT-treatment results between the groups is statistically insignificant.ConclusionsThe investigated strategy suggests using fluorescence control of the efficacy of PDT-treatment (photodynamic theranostics) to optimize and individualize the PDT procedure.     

Synthesis,characterisation and in vitro investigation of photodynamic activity of 5-(4-octadecanamidophenyl)-10,15,20-tris(N-methylpyridinium-3-yl)porphyrin trichloride on HeLa cells using low light fluence rate

Photodynamic therapy (PDT) is a treatment that aims to kill cancer cells by reactive oxygen species, mainly singlet oxygen, produced through light activation of a photosensitiser (PS). Amongst photosensitisers that attracted the most attention in the last decade are cationic and amphiphilic molecules based on porphyrin, chlorin and phthalocyanine structures. Our aim was to join this search for more optimal balance of the lipophilic and hydrophilic moieties in a PS. A new amphiphilic porphyrin, 5-(4-octadecanamidophenyl)-10,15,20-tris(N-methylpyridinium-3-yl)porphyrin trichloride (5) was synthesised and characterised by ¹H NMR, UV–vis and fluorescence spectroscopy, and by MALDI-TOF/TOF spectrometry. In vitro photodynamic activity of 5 was evaluated on HeLa cell lines and compared to the activity of the hydrophilic 5-(4-acetamidophenyl)-10,15,20-tris(N-methylpyridinium-3-yl)porphyrin trichloride (7). Low fluence rate (2 mW cm⁻²) of red light (643 nm) was used for the activation, and both porphyrins showed a drug dose-response as well as a light dose-response relationship, but the amphiphilic porphyrin was presented with significantly lower IC₅₀ values. The obtained IC₅₀ values for 5 were 1.4 μM at 15 min irradiation time and 0.7 μM when the time of irradiation was 30 min, while for 7 these values were 37 and 6 times higher, respectively. These results confirm the importance of the lipophilic component in a PS and show a potential for 5 to be used as a PS in PDT applications.     

Molecular analysis of apoptosis pathway after photodynamic therapy in breast cancer: Animal model study

BackgroundMolecular investigation of breast tumors has permitted better understanding about interaction of genes and pathways involved in tumor progression.ObjectiveThe aim of this study was to evaluate the association between genes belonging to the pathway of apoptosis with tumor response to photodynamic therapy.Study Design/Materials and methodsThe mammary tumors were induced in twenty-four Spraguey-Dawley female rats by oral gavage of 7,12-dimethylbenz(a)anthracene (8 mg/Kg body weight). Animals were divided into three groups: G1 (normal tissue), G2 (tumors without treatment), G3 (animals euthanized 48 h after treatment). The photosensitizer used was a chlorin, 5,15-bis-(2-bromo-5-hydroxyphenyl) chlorin in the dose of 8 mg/kg for each animal. Light source of diode laser at a wavelength of 660 nm, fluence rate of 100 mW/cm, and light dose of 100 J/cm was delivery to lesions for treatment. A sample from each animal was investigated by quantitative real time PCR using Rat Apoptosis RT² Profiler™ PCR Array platform.ResultsPro-apoptotic BAK1, CARD6, CASP8, CIDEA, CIDEB, DAPK1, TNF, TNFRSF10B, FASLG, LOC687813, and TP73 genes showed increased expression, and CD40 anti-apoptotic gene showed decreased expression in the group who underwent PDT (G3) in relation to G2.ConclusionThe results indicated that these genes are involved more directly with cellular apoptosis induced by PDT using the Chlorin photosensitizer.     

DNA analysis of cattle parasitic protozoan Tritrichomonas foetus after photodynamic therapy

Photodynamic therapy (PDT) is a modality of therapy that involves the activation of photosensitive substances and the generation of cytotoxic oxygen species and free radicals to promote the selective destruction of target tissues. This study analyzed the application of PDT to Tritrichomonas foetus, a scourged and etiological agent of bovine trichomoniasis, a sexually transmitted infectious disease. As it is an amitochondrial and aerotolerant protozoan, it produces energy under low O₂ tension via hydrogenosome. T. foetus from an axenic culture was incubated with photosensitizer tetrasulfonated aluminium phthalocyanine and then irradiated with a laser source (InGaAIP) at a density of 4.5 J cm⁻². The DNA integrity of the control and treated group parasites was analyzed by conventional gel electrophoresis and comet assay techniques. In previous results, morphological changes characterized by apoptotic cell death were observed after T. foetus was submitted to PDT treatment. In the treated groups, T. foetus DNA showed a higher concentration of small fragments, about 200 pb, in gel electrophoresis after PDT. In the comet assay, the DNA tail percentage was significantly higher in the treated groups. These results demonstrate that PDT leads to DNA fragmentation with changes in nuclear morphology and apoptotic features.     

Photodynamic therapy: An option in mycosis fungoides

BackgroundPhotodynamic therapy (PDT) is a well-known and effective treatment for non-melanoma skin-cancer. Numerous studies have also shown its effectiveness in mycosis fungoides. The aim of the study was to analyse MF patients treated with PDT at the Dermatology Unit of Bologna University.MethodsWe retrospectively analysed MF patients treated with PDT over the last ten years. Each PDT protocol consisted of the appliance for 3 h under an occlusive film dressing on each lesion of a one-mm-thick layer of 16% methyl aminolaevulinate (MAL) 160 mg/g cream (Metvix^®, Galderma, Paris, France). The cream was then removed and the skin was exposed to 630 nm red light from a diode lamp (Aktilite^®, Galderma Benelux, Rotterdam, the Netherlands), with a total radiation dose of 37 J/cm2 for 9 mins. A protocol of one session every month was scheduled. The treated lesions were clinically examined, before each treatment.ResultsFour cases, three male and one female, had been treated with PDT. Two patch lesions on the plantar area, one leg and the pubic area were treated. The number of PDT sessions ranged from 4 to 9. Two complete remissions and two partial remissions were observed. A low-to-mild burning sensation was reported during the treatment, and persisted over the next day; no further side effects were observed.ConclusionsOur series shows that PDT can be considered an effective second-line treatment in patients characterised by a disease located in difficult-to-treat anatomical areas such as the feet and the pubic area.     

Ruthenium porphyrin-induced photodamage in bladder cancer cells

Photodynamic therapy (PDT) is a noninvasive treatment for solid malignant and flat tumors. Light activated sensitizers catalyze photochemical reactions that produce reactive oxygen species which can cause cancer cell death. In this work we investigated the photophysical properties of the photosensitizer ruthenium(II) porphyrin (RuP), along with its PDT efficiency onto rat bladder cancer cells (AY27). Optical spectroscopy verified that RuP is capable to activate singlet oxygen via blue and red absorption bands and inter system crossing (ISC) to the triplet state. In vitro experiments on AY27 indicated increased photo-toxicity of RuP (20 μM, 18 h incubation) after cell illumination (at 435 nm), as a function of blue light exposure. Cell survival fraction was significantly reduced to 14% after illumination of 20 μM RuP with 15.6 J/cm², whereas the “dark toxicity” of 20 μM RuP was 17%. Structural and morphological changes of cells were observed, due to RuP accumulation, as well as light-dependent cell death was recorded by confocal microscopy. Flow cytometry verified that PDT-RuP (50 μM) triggered significant photo-induced cellular destruction with a photoxicity of (93% ± 0.9%). Interestingly, the present investigation of RuP-PDT showed that the dominating mode of cell death is necrosis.RuP “dark toxicity” compared to the conventional chemotherapeutic drug cisplatin was higher, both evaluated by the MTT assay (24 h).In conclusion, the present investigation shows that RuP with or without photoactivation induces cell death of bladder cancer cells.     

A clinical evaluation of the efficacy of photodynamic therapy in the treatment of erosive oral lichen planus: A case series

BackgroundErosive oral lichen planus (EOLP) poses a substantial risk of malignant transformation into squamous cell cancer. The absence of established treatment gives way to alternative therapeutic strategies, including photodynamic therapy. The aim of the study was to evaluate the efficacy of PDT in the treatment of EOLP.MethodsTwelve female patients aged 63–80 with 22 OLP lesions (16 on the buccal mucosa, 6 on gingiva and tongue), underwent authors’ own PDT scheme with the use of 5% solution of 5-aminolevulinic acid (ALA) as photosensitizer. An ALA-saturated occlusive dressing was applied directly onto a lesion and surrounding mucosa 2 h prior to illumination with a custom-made diode lamp (light of 630 nm, dose of 300 mW). After a series of 10 weekly illumination sessions the patients were monitored for 12 months.ResultsThe mean size of lesions before treatment was 1.46 cm² ± 1.44. The lesions on the buccal mucosa were smaller (1.06 cm² ± 0.98) than those on the gingiva and tongue (2.63 cm² ± 1.93). Post-treatment improvement encompassed 16 lesions, 5 of which were in remission. The mean reduction in size after 10-session therapy was 8,05%. The healing continued and further reduction in size (by 69.13%) took place during the 12-month observation: 39.62% of lesions within the buccal mucosa and full remission of all lesions on the gingiva and tongue.ConclusionsThe results suggest that PDT offers non-invasive treatment of lesions in oral mucosa and may become an alternative and complementary method to those currently in use. Further studies involving larger groups of patients should be undertaken before it becomes routine practice.     

Influence of photodynamic therapy on peripheral immune cell populations and cytokine concentrations in head and neck cancer

BackgroundPhotodynamic therapy (PDT) represents a palliative treatment option for a selected group of patients with head and neck squamous cell carcinoma (HNSCC). PDT induces a local inflammatory reaction with the potential to initiate antitumor immune responses. However, the systemic impact on peripheral immune cells has not been described so far.MethodsHNSCC patients (n = 9) were treated with PDT in a palliative setting. All patients had previously undergone several oncologic treatment regimens. Blood samples were taken before, during and after PDT. Age-matched healthy donors served as control group (NC, n = 15). The frequency and absolute number of T- and B-lymphocytes, CD4⁺CD39⁺ regulatory T-cells (Treg) and NK-cells were measured by 10-color flow cytometry. Serum concentrations of T cell related cytokine panel, including HMGB1, IL-6, IL-10 and perforin were measured by bead array and ELISA.ResultsIn heavily pretreated HNSCC patients, the number and frequency of Treg and NK-cells were increased as compared to NC. PDT induced a further increase of the frequency of Treg and NK-cells in the peripheral blood. Additionally, the serum concentrations of HMGB1, IL-6 and IL-10 showed a significant elevation after treatment with simultaneously decreased perforin levels.ConclusionAlthough PDT is a local treatment regimen, a systemic inflammatory response with altered peripheral immune cell populations and cytokine concentrations is visible. The increased Treg and NK cell numbers after PDT support the hypothesis that PDT may successfully be combined with NK cell or T cell activating immune checkpoint modulators in HNSCC patients to improve HNSCC specific immunity.     

In vitro effects of photodynamic therapy induced by chloroaluminum phthalocyanine nanoemulsion

BackgroundThe photodynamic therapy (PDT) has been used to treat cancer mainly by inducing oxidative stress. Our aim was to evaluate the effect of PDT and its combination with methoxyamine (MX), a blocker of base excision repair (BER), in cells expressing high levels of the APE1 protein, which is involved in cell oxidative damage response.MethodsThe HeLa and A549 cells were treated for 3 h with chloroaluminum phthalocyanine incorporated into a well-designed nanoemulsion (ClAlPc/NE); and then irradiated by visible light (@670 nm) with doses of 0.1, 0.5 and 1.0 J/cm². A simultaneous combination of MX + ClAlPc/NE was performed and then irradiated with the selected dose of 0.5 J/cm². The treatments were evaluated in terms of viability, clonogenicity, DNA fragmentation, and cell death mechanism by apoptosis and/or necrosis.ResultsThe APE1 protein expression observed was higher in HeLa than in A549. Both cell lines exhibited substantial differences in cell cytotoxicity. The PDT decreased the clonogenicity of HeLa by inducing apoptosis (sub-G1 and annexin detection). Additionaly, the MX potentiates the PDT-effects in HeLa. Otherwise, low cytotoxicity was observed in A549 cells.ConclusionThe PDT induced apoptosis in high APE1 expressive HeLa cells, and the blockage of BER by MX increased its effects.     

Effect of photodynamic therapy with two photosensitizers on Streptococcus mutants: In vitro study

Background and objectivesStreptococcus mutans (S. mutans) colonizes the oral cavity and causes dental caries and periodontal diseases. Considering the importance of the treatments that decrease pathogenic microorganisms, the aim of the present research was the assessment of the antimicrobial effect of Photodynamic Therapy (PDT) with Methylene Blue (MB) and Indocyanine Green (IG) photosensitizers on S. mutans.Materials and methodsIn this In vitro experimental study, Sixty four caries-free first premolars were contaminated with 0.5 McFarland S.mutans suspension and were randomly assigned to 4 groups. The teeth in the first group were impregnated with 2% MB while the teeth in the second group were impregnated with 0.2% IG. The teeth in the first group were irradiated with continuous-wave 660 nm dod laser with 40 mw output power, energy density of 2.4 J/cm² and 100% duty cycle for 60 s, while the teeth in the second group were irradiated with continuous -wave 810 nm diode laser with 100 mw out power, density energy of 6 J/cm² and 100% duty cycle for 60 s in contact mode. In the third group, the teeth were suspended in 0.2% Chlorhexidine for 30 s. The fourth group was considered as the control. The teeth were sampled before and after the interventions and the samples were incubated in Blood Agar for 24 h. Afterwards, the number of S. mutans colonies were counted. Data were statistically analyzed by Kruskal-Wallis, Dunn's and Friedman tests.ResultsIn the groups treated with a combination of MB and IG and laser irradiation and also in the Chlorhexidine group, the final number of S. mutans colonies equaled zero. In “MB and IG groups without laser irradiation”, although the amount of microorganisms decreased, but the number of colonies did not reach zero. Pair comparisons by Dunn's test showed that there was a significant difference between “MB and IG groups without laser irradiation” and the other experimental groups p = 0.03).ConclusionPDT with MB and IG photosensitizers and also Chlorhexidine mouthwash, have the ability to completely eradicate S. mutans bacterial colonies.     

Comparison of photoinactivation of T. rubrum by new methylene blue (NMB) and indocyanine green (EmunDo®)

BackgroundSuperficial mycotic skin infections which are predominantly caused by Trichophyton rubrum, poorly responsd to conventional therapies. A great amount of attention has focused on finding more effective treatments. The current work is aimed to compare the effectiveness of phoinactivation of Trichophyton rubrum by two relatively new photosensitizers: a phenothiazinium dye(New methylene blue) and Indocyanine green (EmunDo^®).Materials and methodsA Final inoculum of T. rubrum which corresponded to 10⁶ colony forming unit per milliliter (CFU ml⁻¹) was prepared. Antimicrobial Photodynamic treatment (aPDT) of T. rubrum was carried out by either EmunDo^® (1 mg/ml, Infra-red laser (IRL, λ = 810 nm, Energy Density 55 J/cm²)) or NMB (10 μM, Red laser (RL), λ = 630 nm, Energy Density of 5 J/cm²). The suspensions thereafter were subcultured on Sabouraud dextrose agar (SDA) and were counted on due time. based on colony-forming unit per milliliter (CFU/ml).ResultsaPDT with either EmunDo^® (E) or NMB (N) considerably diminished the viability of inoculated T. rubrum with respective reduction of 0.64 log and 0.4 log compared to the control group (P < 0.001). No significant difference was found between two laser only groups (P = 0.79) and two aPDT groups (P = 0.73), however significant reduction of T. rubrum in red laser only group (P = 0.04) and EmunDo^® only group (P = 0.04) was found as compared to the control group (P < 0.05).ConclusionThe study provides evidence regarding satisfactory photodynamic inactivation of T. rubrum with EmunDo^® or NMB as photosensitizers. Irradiation by only red laser source was found superior to only infra-red laser source. Dark toxicity of EmunDo^® was more successful than new methylene blue dye.     

Photodecomposition,photomutagenicity and photocytotoxicity of retinyl palmitate under He–Ne laser photoirradiation and its effects on photodynamic therapy of cancer cells in vitro

ObjectiveOur aim was to study photodecomposition, photomutagenicity and cytotoxicity of retinyl palmitate (RP), a principal storage form of vitamin A in humans and animals, under He–Ne laser photoirradiation. Moreover, the effect of different concentrations and timing protocol of antioxidants on photodynamic therapy (PDT) is contradictory, so the effect of RP (as antioxidant) on the PDT cytotoxicity was studied.MethodsPhotomutagenicity was tested by Ames test. Photodecomposition was studied by UV–vis spectroscopy. Cytotoxicity was measured with MTT-assay. Moreover, the effect of PDT, using hematoporphyrin derivatives (HpD) as photosensitizer under He–Ne laser irradiation (10 J/cm²), was studied on HeLa cells either with or without RP (1–100 μM) which incubated with the cells for short or long incubation period (1 h or 24 h) prior to PDT.ResultsNo photodecomposition of RP alone was obseved whereas there is a little photodecomposition of RP only in presence of HpD under irradiation with He–Ne laser. Moreover, no photomutagenicity was observed in Salmonella typhimurium strains under laser irradiation in presence or absence of HpD. RP alone (1–100 μM) significantly decrease the viability of HeLa cells. Laser irradiation of HeLa cells pre-incubated with RP alone for 24 h showed further significant decrease in viability of the cells. While RP incubations for 1 h before PDT had slight effect on the cells, 24 h incubation before PDT enhanced the cytotoxicity of PDT on HeLa cells.ConclusionsRP can be used 24 h before PDT to enhance its effects. RP is not mutagenic under irradiation with He–Ne laser.     

Photodynamic therapy in the management of basal cell carcinoma: Retrospective evaluation of outcome

IntroductionPhotodynamic therapy (PDT) is a relatively new method of treating various kinds of pathologies. In this retrospective study, a total of 148 patients with basal cell carcinoma (BCC) were treated with surface illumination methyl aminolevulinate – photodynamic therapy (MAL-PDT) or meta-tetrahydroxyphenylchlorin (mTHPC-PDT). Comparisons with the clinical features, rate of recurrence and overall outcome were made.Materials and methodsSurface illumination PDT was offered under local or general anaesthesia. For thin BCCs, the 16% strength cream (MAL) was applied topically 3 h prior to tissue illumination. A single-channel 628 nm diode laser was used for illumination and light was delivered at 100J/cm² per site. For thick BCCs, 0.05 mg/kg mTHPC was administered intravenously prior to tissue illumination. A single-channel 652 nm diode laser was used for illumination and light was delivered at 20J/cm² per site. Lesion response evaluation was carried out according to RECIST.ResultsThe MAL-PDT sub-group included 86 patients with 127 thin BCCs; 80 patients had complete response (CR) after one round of treatment. The mTHPC-PDT sub-group included 62 patients with 116 thick BCCs; 60 patients had complete response after one round of treatment. Statistically significant factors associated with complete response to MAL-PDT included superficial BCC histotype (P < 0.001), ≤0.5 mm tumour thickness (P < 0.001) and lack of ulceration (P < 0.001). While for the mTHPC-PDT sub-group, both superficial and nodular types responded significantly better than invasive type (P < 0.001); the lack of ulceration was insignificant factor in achieving complete response.ConclusionPDT achieved high efficacy in the treatment of basal cell carcinomas with greatly reduced morbidity and disfigurement. The technique is simple, can commonly be carried out in outpatient clinics, and is highly acceptable to patients.     

Tetrahydroporphyrin-tetratosylat (THPTS): A near-infrared photosensitizer for targeted and efficient photodynamic therapy (PDT) of human bladder carcinoma. An in vitro study

BackgroundEfficacy of PDT in muscle-invasive bladder cancer is hampered by low tissue penetration of most photosensitizers by short excitation wavelength. THPTS is excitable at near-infrared (760 nm) allowing tissue penetration up to 15 mm. We examined the cellular effects of THPTS-PDT in human bladder cancer cells.Material and methodsWe used four human transitional carcinoma cell lines, epithelial bladder progenitors (HBLAK) and bladder smooth muscle cells (HBSMC). We used flow cytometry to examine pharmacokinetics of THPTS, confocal laser scanning microscopy to analyze subcellular localization and production of reactive oxidative species (ROS), examined cytotoxicity and cell death pathways (qRT-PCR).ResultsTotal uptake varied between cell lines and was significantly high in HBLAK and HBSMC. Lysosomal localization was mainly seen in cancer cells and HBLAK, while THPTS was distributed throughout the cytoplasm in HBSMC. Significant ROS production was detected 30 min after THPTS-PDT. Growth arrest occurred within 4 h and resulted in apoptotic and necrotic cytotoxicity after 24 h. Cytotoxicity was dose-dependent and specifically high in cancer cells and HBLAK and significantly low in HBSMC.ConclusionTHPTS-PDT induces cellular mechanisms leading to cellular growth arrest, apoptosis and necrosis in human bladder cancer cells. These effects are only partly dependent on the total amount of THPTS uptake and rather dependent on its subcellular compartmentalization. HBSMC are hardly affected by THPTS-PDT confirming tumor specificity and safety. THPTS is a promising new photosensitizer with the unique advantage of deep tissue penetration allowing the treatment of solid tumors and warranting further animal studies.