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.     

Assessing daylight & low-dose rate photodynamic therapy efficacy,using biomarkers of photophysical,biochemical and biological damage metrics in situ

BackgroundSunlight can activate photodynamic therapy (PDT), and this is a proven strategy to reduce pain caused byconventional PDT treatment, but assessment of this and other alternative low dose rate light sources, and their efficacy, has not been studied in an objective, controlled pre-clinical setting. This study used three objective assays to assess the efficacy of different PDT treatment regimens, using PpIX fluorescence as a photophysical measure, STAT3 cross-linking as a photochemical measure, and keratinocyte damage as a photobiological measure.MethodsNude mouse skin was used along with in vivo measures of photosensitizer fluorescence, keratinocyte nucleus damage from pathology, and STAT3 cross-linking from Western blot analysis. Light sources compared included a low fluence rate red LED panel, compact fluorescent bulbs, halogen bulbs and direct sunlight, as compared to traditional PDT delivery with conventional and fractionated high fluence rate red LED light delivery.ResultsOf the three biomarkers, two had strong correlation to the PpIX-weighted light dose, which is calculated as the product of the treatment light dose (J/cm²) and the normalized PpIX absorption spectra. Comparison of STAT3 cross-linking to PpIX-weighted light dose had an R = 0.74, and comparison of keratinocyte nuclear damage R = 0.70. There was little correlation to PpIX fluorescence. These assays indicate most of the low fluence rate treatment modalities were as effective as conventional PDT, while fractionated PDT showed the most damage.ConclusionsDaylight or artificial light PDT provides an alternative schedule for delivery of drug-light treatment, and this pre-clinical assay demonstrated that in vivo assays of damage could be used to objectively predict a clinical outcome in this altered delivery process.     

Silica Nanoparticles Encapsulated Cichorium Pumilum as a Promising Photosensitizer for Osteosarcoma Photodynamic Therapy: In-vitro study

Background/AimsSilica nanoparticles (SiNPs) have been promising vehicles for drug delivery. Cichorium Pumilum (CP), a natural photosensitizer (PS), has been reported to have many useful effects in cancer treatment. However, the poor water solubility and its low bioavailability have confined its use as a suitable photosensitizer for photodynamic therapy. Therefore, a subtle approach is required to overcome these drawbacks.Materials and MethodsWe have synthesized a silica nanoparticles loaded with Cichorium Pumilum. The nanoparticles structural morphologies have been charectrized by Transmission Electron Microscopy (TEM). The cytotoxicity for different concentrations of naked and encapsulated CP was evaluated. Moreover, the optimal concentration of naked and encapsulated CP with exposure time to a light (Maximum intensity at 350nm ∼0.27mW/cm²) required to eliminate the used cells (Osteosarcoma cells) were also measured.ResultsThe results showed that encapsulated CP in SiNPs exhibited relatively higher efficacy than the naked CP by + 157.14 % of exposure time efficacy and + 49.45% of concentration efficacy, and encapsulated CP was also confirmed to be effective in eradicating osteosarcoma cells.ConclusionThe engineered silica nanoparticles loaded with CP enhanced the photodynamic therapy by increasing the CP bioavailability.     

In-Vitro Use of Verteporfin for Photodynamic Therapy in Glioblastoma

BackgroundStummer et al. established fluorescence-guided surgery (FGS) for glioblastoma (GBM) using 5-aminolevulinic acid (5-ALA). Its metabolite, protoporphyrin IX (PPIX), is also a photosensitizer and can be used for photodynamic therapy (PDT) using a laser beam of 635 nm. The porphyrin derivate verteporfin (VP) was discovered to have properties to penetrate the brain, pharmacologically target glioma cells, and is approved for PDT of choroidal neovascularization in wet age-related macular degeneration at 689 nm.ObjectiveTo elucidate whether GBM cell lines are susceptible to PDT with second-generation photosensitizer VP.MethodsHuman glioma cell lines LN229, HSR-GBM1, and a low-passage patient-derived GBM cell line P1 were treated with variable concentrations of VP for 24 h, followed by PDT at 689 nm using a diode laser light. Cell viability was measured using the MTT assay and VP uptake was measured using a desktop cytometer.ResultsSignificantly higher cell death following PDT with VP compared to VP treatment alone or no treatment was detected in all cell models (LN229, HSR-GBM1, P1). Flowcytometric measurements revealed a concentration-dependent cellular uptake of VP after 24 h incubation up to 99% at 10 µM (HSR-GBM1).ConclusionThis study demonstrates that PDT with VP causes cell death in GBM cells at marginal concentrations. Additionally, red spectrum fluorescence was detected at therapeutic concentrations in all cell lines, validating the cellular uptake of VP in GBM cells. VP, therefore, is not only a potential drug for targeting GBM pharmacologically but can be used as an optical imaging dye in surgery and photosensitizer to make GBM susceptible to PDT.     

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.     

Genetic deviation associated with photodynamic therapy in HeLa cell

Photodynamic therapy (PDT) is a method that is used in cancer treatment. The main therapeutic effect is the production of singlet oxygen (¹O₂). Phthalocyanines for PDT produce high singlet oxygen with absorbers of about 600–700 nm.AimIt is aimed to analyze cancer cell pathways by flow cytometry analysis and cancer-related genes with q-PCR device by applying phthalocyanine L1ZnPC, which we use as photosensitizer in photodynamic therapy, in HELA cell line. In this study, we investigate the molecular basis of L1ZnPC's anti-cancer activity.Material methodThe cytotoxic effects of L1ZnPC, a phthalocyanine obtained from our previous study, in HELA cells were evaluated and it was determined that it led to a high rate of death as a result. The result of photodynamic therapy was analyzed using q-PCR. From the data received at the conclusion of this investigation, gene expression values were calculated, and expression levels were assessed using the 2^−∆∆Ct method to examine the relative changes in these values. Cell death pathways were interpreted with the FLOW cytometer device. One-Way Analysis of Variance (ANOVA) and the Tukey-Kramer Multiple Comparison Test with Post-hoc Test were used for the statistical analysis.ConclusionIn our study, it was observed that HELA cancer cells underwent apoptosis at a rate of 80% with drug application plus photodynamic therapy by flow cytometry method. According to q-PCR results, CT values ​​of eight out of eighty-four genes were found to be significant and their association with cancer was evaluated. L1ZnPC is a new phthalocyanine used in this study and our findings should be supported by further studies. For this reason, different analyses are needed to be performed with this drug in different cancer cell lines. In conclusion, according to our results, this drug looks promising but still needs to be analyzed through new studies. It is necessary to examine in detail which signaling pathways they use and their mechanism of action. For this, additional experiments are required.     

Photodynamic therapy using a cytotoxic photosensitizer porphyrus envelope that targets the cell membrane

BackgroundSubcellular localization of a photosensitizer is known to determine the therapeutic efficacy of photodynamic therapy (PDT). Cell membrane is an optimal target that promises an effective treatment outcome.ObjectivesWe previously developed a novel photosensitizer named porphyrus envelope (PE) by combining hemagglutinating virus of Japan envelope (HVJ-E) with lipidated protoporphyrin IX (PpIX lipid). In the current study, the cellular localization of PE and its ability to induce multiple anti-tumor effect were characterized.Materials and MethodsThe localization and uptake of PpIX lipid in cells were evaluated with confocal laser scanning microscopy and a cell-based fluorescent assay, respectively. The ability of PE to suppress the migration and proliferation of cancer cells was assessed using a scratch-wound assay. The synergistic effect of PDT and HVJ-E treatment was evaluated using an in vitro experiment with PC-3 cells.ResultsPE localized along the cell membrane and PpIX lipid accumulated selectively in the prostate cancer cells within 10 min. Also, PE maintained the ability to undergo fusion and induce cancer cell death even after light irradiation at the dose for PDT. Incubation with PE resulted in delayed migratory and proliferative activity of PC-3 cells. PE-mediated PDT was twice as effective when cells were further incubated with PE following PDT.ConclusionsPE allows rapid drug delivery targeting the cell membrane. Because the cytotoxicity of HVJ-E was maintained, synergistic effect of HVJ-E and the photochemical reactions resulted in highly effective killing of prostate cancer cells in vitro and thus represents a promising treatment for prostate cancer.     

Skin fluorescence following photodynamic therapy with NPe6 photosensitizer

BackgroundThe second-generation photosensitizer NPe6 has strong anti-tumor effects with a much shorter photosensitive period than the first-generation photosensitizer Photofrin. Although photosensitive period has been reduced, skin photosensitivity is still a major side effect of photodynamic therapy (PDT). Therefore, we conducted a prospective study to investigate whether the NPe6 fluorescence intensity in skin after PDT could be measured effectively in human patients to improve the management of a patient's photosensitive period.MethodsThe NPe6 fluorescence measurements using a constructed fluorescence sensing system at the inside of the arm were acquired prior to and 5 and 10 min after NPe6 administration as well as at the time of PDT (4–5 h after administration), at discharge (2 or 3 days after PDT), and at 1 or 2 weeks after PDT. Participants were interviewed as to whether they had any complications at 2 weeks after PDT.ResultsNine male patients and one female patient entered this study. Nine patients were inpatients and one patient was an outpatient. All of the measurements of NPe6 fluorescence in the skin could be obtained without any complications. The spectral peak was detected at the time of discharge (2–3 days after administration) in most cases and it decreased at 1 or 2 weeks after PDT.ConclusionsThe fluorescence of NPe6 in the skin could be detected feasibly using the fluorescence sensing system in human patients. Measuring the relative concentration of NPe6 in the skin indirectly by measuring fluorescence intensity might be useful to predict the period of skin photosensitivity after PDT.     

Efficacy of antimicrobial photodynamic therapy in reducing oral yeasts carriage among individuals using electronic nicotine delivery systems

Objective: The aim was to assess the efficacy of antimicrobial photodynamic therapy (aPDT) in reducing oral yeasts carriage among individuals using electronic nicotine delivery systems (ENDS).Methods: Self-reported ENDS users and non-users (individuals that reported to have never used any nicotinic product) were included. Demographic data was collected using a questionnaire. Patients were divided into 2 subgroups: (a) aPDT group; and (b) sham aPDT group. aPDT was performed using a curcumin-based photosensitizer that was exposed to a central wavelength of 660 nm and an estimated average fluency of 200 J/cm². The system delivered light by uniform diffusion for 5 min. Sham aPDT was performed using a non-activated laser tip. Oral yeasts colony forming units were determined using standard techniques. Oral yeasts were assessed at baseline and at 3-months of follow-up. Level of significance was set at P<0.05.Results: Twenty-three ENDS-users (19 males and 4 females) and 23 controls (17 males and 6 females) were included. ENDS-users were vaping for 8.3 ± 0.6 years and were using their ENDS devices 13.6 ± 2.7 times daily. Toothbrushing twice daily was reported by 8.7% and 21.7% of ENDS-users and controls, respectively. Tongue brushing was reported by none of the individuals. At baseline, oral yeasts CFU/ml were significantly higher among ENDS-users in the PDT (P<0.05) and sham PDT (P<0.05) groups compared with controls (Table 2; Figure 1). At 3-months of follow-up, CFU/ml were significantly higher among ENDS-users in the PDT (P<0.05) and sham PDT (P<0.05) groups compared with controlsConclusion: A single session of aPDT is ineffective in reducing the oral yeasts CFU/ml in ENDS-users. Further studies are needed to assess the impact of multiple sessions of aPDT in reducing the oral yeasts CFU/ml in ENDS-users.     

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.     

Antifungal effect of a new photosensitizer derived from BODIPY on Candida albicans biofilms

BackgroundPhotodynamic therapy (PDT) may be an alternative treatment of Candida albicans (C. albicans) infections. The aim of this study was to investigate the antifungal effect of PDT mediated by a new photosensitizer (PS) derived from BODIPY (BDP-4L) on C. albicans biofilms.MethodsC. albicans biofilms were incubated with BDP-4L of different concentrations and then irradiated at the light doses of 1.8, 3.6, 5.4, 7.2 and 9.0 J/cm². XTT reduction assay was conducted to determine the PS concentration and PDT parameters. Confocal light scanning microscopy (CLSM) and scanning electron microscope (SEM) were used to visualize and quantify the effect of BDP-4L on C. albicans biofilms after PDT.ResultsC. albicans biofilms were inactivated in light dose-dependent and PS concentration-dependent manners using BDP-4L as PS. Without irradiation, no inactivation effect was observed when PS concentrations varied from 5 μM to 80 μM. 40 μM PS with 3.6 J/cm² irradiation resulted in a significant reduction of 83.8% in biofilm metabolic activities. CLSM assay demonstrated that cell viability was obviously inhibited by 82.6%. SEM images revealed ruptured and rough cell surface, indicating increased cell membrane permeability after PDT.ConclusionsOur results suggested that BDP-4L mediated PDT exhibited a favorable antifungal effect on C. albicans biofilms.     

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 of the Canine Prostate: Intra-arterial Drug Delivery

Purpose Interstitial photodynamic therapy (PDT) selectively destroys tissue targeted with a photosensitizer and then exposed to light of a specific wavelength. We report a novel delivery method—intra-arterial drug delivery for PDT of the prostate—in a canine model. Methods To evaluate drug distribution, the prostatovesical artery was selectively cannulated and photosensitizers alone or in conjunction with 99m-technetium-labeled macro-aggregated albumin (^99mTc-MAA) were injected via a 3 Fr microcatheter in 8 animals. One dog was followed for 3 months to determine tolerance and toxicity. The remaining animals were euthanized and imaged with whole-body single photon emission CT and gamma counting for radioactivity distribution. Photosensitizer distribution was further analyzed by fluorescence confocal microscopy and tissue chemical extraction. To evaluate PDT, the photosensitizer QLT0074 was infused in 3 animals followed by interstitial illumination with 690 nm laser light. Results Intra-arterial infusion selectively delivered drugs to the prostate, with both radioactivity and photosensitizer levels significantly higher (up to 18 times) than in the surrounding organs (i.e., rectum). With unilateral injection of ^99mTc-MAA, only the injected half of the prostate showed activity whereas bilateral administration resulted in drug delivery to the entire prostate. PDT resulted in comprehensive damage to the prostate without severe complications or systemic toxicity. Conclusion Injection of radiolabeled MAA into the prostatovesical artery results in distribution within the prostate with negligible amounts reaching the adjacent organs. PDT also demonstrates selective damage to the prostate, which warrants clinical application in targeted prostate therapies.     

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.     

Norsquaraine endowed with anticancer and antibacterial activities

BackgroundPhotodynamic therapy (PDT) is a method for the treatment of cancer. Furthermore, PDT can also be used for the eradication of bacteria. The photo-sensitizing drug, a.k.a photosensitizer, is critical for the success of PDT. Although norsquaraines are analogs of squaraine dyes, they are overlooked as photosensitizers.MethodsIn this work, synthesis, characterization, bioimaging and in vitro PDT applications of a new norsquaraine dye 1 were described. We also prepared nanoparticles from norsquaraine 1 and Pluronic F127 to obtain 1@F127.ResultsNorsquaraine 1 boosted the generation of reactive oxygen species over a wide range of pH (pH 8.0, 7.0, 6.0, and 2.2.). Furthermore, 1 was internalized by epidermoid laryngeal carcinoma Hep-2 (Hep-2) cells and used for fluorescence imaging. Remarkably, norsquaraine 1 destroyed most of the cancer cells (ca. 77% to 89%) after illumination with red light. Most strikingly, 1 successfully inhibited the growth of Methicillin-resistant Staphylococcus aureus (MRSA) upon illumination. Last but not least, photodynamic sterilization of tomato juice, an acidic beverage, was feasible using 1 as a photo sterilizer. Nano formulation of 1 with Pluronic F127 provided 1@F127 nanoparticles. It is lucid that 1@F127 nanoparticles permeate into Hep-2 cells and boost the generation of ROS upon illumination.ConclusionNorsquaraine 1 shows superior features as a photosensitizer pertinent to PDT in a wide range of pH. This norsquaraine is endowed with anticancer and antibacterial activities. Which should be further evaluated.     

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 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.     

The effect of photodynamic therapy on head and neck squamous cell carcinoma cell lines using spirulina platensis with different laser energy densities

BackgroundConsidering the anti-cancer properties of spirulina platensis (S. platensis), we aimed to investigate the effectiveness of this algae as a novel natural photosensitizer for photodynamic therapy (PDT) against oral and hypopharyngeal cancer cells. The appropriate laser energy density to apply during PDT was also determined.Methods and MaterialsCAL-27, FaDu and HGF cell lines were exposed to S. platensis with concentrations of 0.3 g/l and 0.6 g/l and were irradiated with 635 nm diode laser using 2, 4, 12, and 24 J/cm² energy densities with constant power. MTT assay was performed to investigate cell viability and cytotoxicity after 24 h. The results were analyzed using two-way ANOVA and post hoc Tukey tests (P-value<0.05).Resultssurvival rate in CAL-27 (P-Value<0.001) and FaDu (P-Value<0.001) cell lines were significantly different following irradiation with various laser energy densities. Different concentrations of S. platensis had no significant effect on the viability of CAL-27 cells (P-Value=0.158) and FaDu cells (P-Value=0.072) and showed no significant cytotoxicity against HGF cells, with or without laser.ConclusionS. platensis could be considered as a novel safe and effective natural photosensitizer for cancer PDT with no cytotoxic effect on normal cells. When combined with laser using appropriate energy densities, it has the ability to induce death in oral and hypopharyngeal cancer cell lines.     

Phototoxicity in a laryngeal cancer cell line enhanced by a targeting amphiphilic chlorin photosensitizer

BackgroundPhotodynamic therapy (PDT) has been established in several countries as an alternative therapy for the treatment of various malignancies. This therapy involves the incorporation of a photosensitizer (PS) that is activated by visible light and form reactive oxygen species leading to target cell death by apoptosis or necrosis. Previously, our group has demonstrated that CHL-T (semi-synthesized from chlorophyll a and containing a linked solubilizing group TRISMA^®) presented a pronounced potential to induce death in HeLa cell line after PDT. In the present study, besides confirm the high cytotoxicity in another cell line, we have further investigated the cell death mechanisms caused by CHL-T as a photosensitizer in laryngeal carcinoma cells.MethodsCells were exposed to different concentrations of three photosensitizers, namely, hypericin (HY), unmodified chlorin (CHL) and a synthesized amphiphilic chlorin derivative (CHL-T). PSs accumulation and localization were accessed by fluorescence assays. Photosensitization was induced at 6 J cm⁻² using red LEDs (630 ± 10 nm). Viability was assessed by mitochondrial function (MTT); whereas apoptosis/necrosis was evaluated by fluorescence microscopy and flow cytometry. Expression of pro-apoptotic p53 protein was studied by Western blot.Results and conclusionsAll PS showed similar localization profile in the HEp-2 cells. The use of CHL-T increased the percentage of apoptotic cells and also p53 expression in comparison with the use of HY and CHL as photosensitizers. This study shows a significant effect of CHLT associated with red light (630 ± 10 nm and 18 mW cm⁻²) irradiation on a cancer cell line, indicating the potential of this amphiphilic chlorin in enhancing the therapeutic effectiveness of Photodynamic Therapy (PDT).