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Phototherapies are promising for noninvasive treatment of aggressive tumors, especially when combining heat induction and oxidative processes. Herein, we show enhanced phototoxicity of gold shell-isolated nanorods conjugated with toluidine blue-O (AuSHINRs@TBO) against human colorectal tumor cells (Caco-2) with synergic effects of photothermal (PTT) and photodynamic therapies (PDT). Mitochondrial metabolic activity tests (MTT) performed on Caco-2 cell cultures indicated a photothermal effect from AuSHINRs owing to enhanced light absorption from the localized surface plasmon resonance (LSPR). The phototoxicity against Caco-2 cells was further increased with AuSHINRs@TBO where oxidative processes, such as hydroperoxidation, were also present, leading to a cell viability reduction from 85.5 to 39.0%. The molecular-level mechanisms responsible for these effects were investigated on bioinspired tumor membranes using Langmuir monolayers of Caco-2 lipid extract. Polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) revealed that the AuSHINRs@TBO incorporation is due to attractive electrostatic interactions with negatively charged groups of the Caco-2 lipid extract, resulting in the expansion of surface pressure isotherms. Upon irradiation, Caco-2 lipid extract monolayers containing AuSHINRs@TBO (1:1 v/v) exhibited ca. 1.0% increase in surface area. This is attributed to the generation of reactive oxygen species (ROS) and their interaction with Caco-2 lipid extract monolayers, leading to hydroperoxide formation. The oxidative effects are facilitated by AuSHINRs@TBO penetration into the polar groups of the extract, allowing oxidative reactions with carbon chain unsaturations. These mechanisms are consistent with findings from confocal fluorescence microscopy, where the Caco-2 plasma membrane was the primary site of the cell death induction process.

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Phthalocyanine (Pc) dyes are photoactive molecules that can absorb and emit light in the visible spectrum, especially in the red region of the spectrum, with great potential for biological scopes. For this target, it is important to guarantee a high Pc solubility, and the use of suitable pyridinium units on their structure can be a good strategy to use effective photosensitizers (PSs) for photodynamic therapy (PDT) against cancer cells. Zn(II) phthalocyanines (ZnPcs) conjugated with thiopyridinium units (1-3) were evaluated as PS drugs against B16F10 melanoma cells, and their photophysical, photochemical, and in vitro photobiological properties were determined. The photodynamic efficiency of the tetra- and octa-cationic ZnPcs 1-3 was studied and compared at 1, 2, 5, 10, and 20 µM. The different number of charge units, and the presence/absence of a-F atoms on the Pc structure, contributes for their PDT efficacy. The 3-(4',5'-dimethylthiazol-2'-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays on B16F10 melanoma cells show a moderate to high capacity to be photoinactivated by ZnPcs 1-3 (ZnPc 1 > ZnPc 2 > ZnPc 3). The best PDT conditions were found at a Pc concentration of 20 µM, under red light (λ = 660 ± 20 nm) at an irradiance of 4.5 mW/cm2 for 667 s (light dose of 3 J/cm2). In these conditions, it is noteworthy that the cationic ZnPc 1 shows a promising photoinactivation ratio, reaching the detection limit of the MTT method. Moreover, these results are comparable to the better ones in the literature.

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The present study examines the design of DNA polymeric films (DNA-PFs) associated with aluminum chloride phthalocyanine (AlClPc) (DNA-PFs-AlClPc), as a promising drug delivery system (DDS), applicable for breast cancer treatment and early-stage diagnosis using photodynamic therapy (PDT). This study starts evaluating (MCF7) as a model for breast cancer cell behavior associated with DNA-PFs. Analyses of the morphological behaviors, biochemical reaction, and MCF7 cell adhesion profile on DNA-PFs were evaluated. SEM and AFM analysis allowed the morphological characterization of the DNA-PFs. Cell viability and cell cycle kinetics studies indicate highly biocompatible material capable of anchoring MCF7 cells, allowing the attachment and support of cell in the same structure where the insertion of AlClPc (DNA-PFs-AlClPc). The application of visible light photoactivation based on classical PDT protocol over the DNA-PFs-AlClPc showed a reduction in cell viability with increased cell death proportional to the fluency energy range from 600, 900, and 1800 mJ cm-2. The 3D organoid system mimics the tumor microenvironment which was precisely observed in human breast cancer in early-stage progression in the body. The results observed indicate that the viability was reduced by more than 80% in monolayer culture and around 50% in the 3D organoid cell culture at the highest energy fluency (1800 mJ cm-2). With low energy fluency (100 mJ cm-2,), the DNA-PFs-AlClPc did not show a cytotoxic effect on MCF7 cells, enabling the potential for photodiagnosis of early-stage human breast cancer detection in the initial stage of progression.

Assuntos

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Recently, Titanium dioxide (TiO2) has been studied as an alternative to treat cancer diseases under different activation therapies. The aim of this review was to describe the effect of TiO2 nanoparticles (NPs) on some cancer cell lines and their interaction with phototherapies such as photodynamic therapy (PDT), photothermal therapy (PTT), sonodynamic therapy (SDT), and ultraviolet therapy (UV) for anticancer treatment. The use of TiO2 combined with PDT, PTT, SDT, or UV has shown a remarkable capacity to enhance the killing of cancer cells through reactive oxygen species formation. Thus, the combination of TiO2 and activation therapies exhibited great potential and could be a viable anticancer treatment strategy. However, more studies on phototherapies in combination with TiO2 and their effects under different experimental conditions (TiO2 concentration, type of cancer cells, and intensity and frequency of therapies) are necessary to guarantee the safe use of this kind of therapy.

Assuntos

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To enhance the efficacy of photodynamic therapy (PDT) for actinic keratosis (AKs), physical and chemical pre-treatments, such as calcipotriol (CAL) have been suggested. To compare the long-term 12-month efficacy and safety between methylaminolevulinate (MAL)-PDT and prior application of topical CAL versus conventional MAL-PDT for AKs of the scalp. Twenty patients with multiple AKs on the scalp were randomized to receive conventional PDT on one side of the scalp and CAL-assisted PDT, in which CAL was applied daily for 15 days beforehand, on the other side. Patients were evaluated for AK clearance at three, six and 12 months thereafter. All 20 patients completed the study. At three months, overall AK clearance was 92.07% and 82.04% for CAL-PDT and conventional PDT, respectively (p < 0.001). Similar results were found at six and 12 months: 92.07% and 81.69% (p < 0.001), and 90.69% and 77.46% (p < 0.001) for CAL-PDT and conventional PDT, respectively. Grade I AKs showed a similar response rate for both sides (p = 0.055) at three months and significant differences were obtained at six (p = 0.001) and 12 months (p < 0.001) for CAL-PDT and conventional PDT. Grade II AKs showed greater improvement on the CAL-PDT side (89.55% vs 62.90%) (p < 0.001) at three months. No difference was found at six and 12 months. CAL-PDT proved to be safe and more effective than conventional PDT for the treatment of AKs on the scalp after 12 months. CAL pre-treatment may have enhanced the efficacy of PDT for AK treatment, however, larger trials are needed to corroborate our findings.

Assuntos

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Lipid oxidation is ubiquitous in cell life under oxygen and essential for photodynamic therapy (PDT) of carcinomas. However, the mechanisms underlying lipid oxidation in rather complex systems such as plasma membranes remain elusive. Herein, Langmuir monolayers were assembled with the lipid extract of glandular breast cancer (MCF7) cells and used to probe the molecular interactions allowing adsorption of the photosensitizer (PS) erythrosine B and subsequent photooxidation outcomes. Surface pressure (π) versus area (cm2/mL) isotherms of MCF7 lipid extract shifted to larger areas upon erythrosine incorporation, driven by secondary interactions that affected the orientation of the carbonyl groups and lipid chain organization. Light-irradiation increased the surface area of the MCF7 lipid extract monolayer containing erythrosine owing to the lipid hydroperoxidation, which may further undergo decomposition, resulting in the chain cleavage of phospholipids and membrane permeabilization. Incorporation of erythrosine by MCF7 cells induced slight toxic effects on in vitro assays, differently of the severe phototoxicity caused by light-irradiation, which significantly decreased cell viability by more than 75% at 2.5 × 10-6 mol/L of erythrosine incubated for 3 and 24 h, reaching nearly 90% at 48 h of incubation. The origin of the phototoxic effects is in the rupture of the plasma membrane shown by the frontal (FSC) and side (SSC) light scattering of flow cytometry. Consistent with hydroperoxide decomposition, membrane permeabilization was also confirmed by cleaved lipids detected in mass spectrometry and subsidizes the necrotic pathway of cell death.

Assuntos

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Colorectal cancer (CRC) is one type of cancer with high morbidity and mortality worldwide. Photodynamic therapy (PDT), a promising new therapeutic approach for cancer, induces tumor damage through photosensitizer-mediated oxidative cytotoxicity. Hypericin is a powerful photosensitizer with pronounced tumor-localizing properties. In this study, we investigated the phototoxic effects of hypericin-mediated PDT (HYP-PDT) in HCT116 and SW620 cells. We validated that HYP-PDT inhibited cell proliferation, triggered intracellular reactive oxygen species generation, induced S phase cell cycle arrest and apoptosis of HCT116 and SW620 cells. Mechanistically, the results of western blot showed that HYP-PDT downregulated CDK2 expression through decreasing the CDC25A protein, which resulted in the decrease of CDK2/Cyclin A complex. Additionally, HYP-PDT induced DNA damage as evidenced by ATM activation and upregulation of p-H2AX. Further investigation showed that HYP-PDT significantly increased Bax expression and decreased Bcl-2 expression, and then, upregulated the expression of cleaved caspase-9, cleaved caspase-3 and cleaved PARP, thereby inducing apoptosis in HCT116 and SW620 cells. In conclusion, our results indicated that the CDC25A/CDK2/Cyclin A pathway and the mitochondrial apoptosis pathway were involved in HYP-PDT induced S phase cell cycle arrest and apoptosis in colorectal cancer cells, which shows HYP could be a probable candidate used for treating colorectal cancer.

Assuntos

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Since Leishmania parasites exhibit resistance outbreaks to drugs conventionally used in medical treatments, research of new antileishmanial compounds or alternative treatment therapies are essential. A focus of interest has been the implementation of light-based therapies such as photodynamic therapy, where inorganic compounds such as titanium dioxide have shown promising results as drug delivery carriers. In this work, nanoparticles of TiO2 doped with Zn (TiO2/Zn) were synthesized through solution combustion route and with hypericin (HY) in order to enhance its photodynamic activity in the visible light region. Scanning (SEM) and transmission (TEM) electron microscopy analyses showed particles of (TiO2/Zn) with sizes smaller than 20 nm and formation of aggregates smaller than 1 µm, whilst electron diffraction spectroscopy (EDS) analysis ensured the presence of Zn in the system. The association of the TiO2/Zn with HY (TiO2/Zn-HY) was further confirmed by fluorescence spectrometry. Measurements of its cellular uptake showed the presence of smaller molecules into promastigotes after 120 min incubation. TiO2/Zn-HY showed good antileishmanial activity (EC50 of 17.5 ± 0.2 µg mL-1) and low cytotoxicity against murine macrophages (CC50 35.2 ± 0.3 µg mL-1) in the visible light (22 mW cm-2; 52.8 J cm-2). Moreover, in the in vivo analysis, TiO2/Zn-HY decreased the parasite load of L. amazonensis - BALB/c infected mice by 43% - 58% after a combination of blue and red light presenting 22 mW cm-2 of intensity and 52.8 J cm-2 of fluency delivered. All together, these data indicate a new combined system of nanoparticles associated with a photosensitizer and PDT as alternative to amphotericin B for the treatment of cutaneous leishmaniasis.

Assuntos

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BACKGROUND: Glioblastoma multiforme (GBM) is a tumor characterized by rapid cell proliferation and migration. GBM constitutes the most aggressive and deadly type of brain tumor and is classified into several subtypes that show high resistance to conventional therapies. There are currently no curative treatments for malignant glioma despite the numerous advances in surgical techniques, radiotherapy, and chemotherapy. Therefore, alternative approaches are required to improve GBM treatment. METHODS: Our study proposes the use of photodynamic therapy (PDT) for GBM treatment, which uses chloro-aluminum phthalocyanine (AlClPc) encapsulated in a new drug delivery system (DDS) and designed as a nanoemulsion (AlClPc/NE). The optimal dark non-cytotoxic AlClPc/NE concentration for the U87 MG glioma cell model and the most suitable laser light intensity for irradiation were determined. Experimental U87 MG cancer cells were analyzed via MTT cell viability assay. Cellular localization of AlClPc, morphological changes, and cell death via the necrotic and apoptotic pathways were also evaluated. RESULTS: AlClPc remained in the cytoplasmic region at 24h after administration. Additionally, treatment with 1.0µmol/L AlClPc under light irradiation at doses lower than 140mJ/cm resulted in morphological changes with 50±6% cell death (p<0.05). Moreover, 20±2% of U87 MG cells underwent cell death via the necrotic pathway. Measurement of Caspase-9 and -3 activities also suggested that cells underwent apoptosis. Taken together, these results indicate that AlClPc/NE-PDT can be used in the treatment of glioblastoma by inducing necrotic and apoptotic cell death. CONCLUSIONS: Our findings suggest that AlClPc/NE-PDT induces cell death in U87 MG cells in a dose-dependent manner and could thus serve as an effective adjuvant treatment for malignant glioma. AlClPc/NE-PDT utilizes a low dose of visible light and can be used in combination with other classic GBM treatment approaches, such as a combination of chemotherapy and surgery.

Assuntos

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Sixteen porphyrins, including neutral, anionic and cationic meso-(aryl)porphyrins and meso-(1-methyl-4-pyridinium)porphyrins were herein evaluated in terms of their photosensitizing properties against HaCaT keratinocytes. After an initial screening, the cationic porphyrins were studied in more details, by both determining their log POW and performing PDT assays in lower porphyrin concentrations. Porphyrins presenting two or more adjacent positively charged groups, directly linked to the macrocycle meso positions, appeared to be the most effective photosensitizers. The present study also included the dicationic 5,10-diphenyl-15,20-di(1-methylpyridinium-4-yl)porphyrin (14b), which has previously shown promising results on a psoriasis-like in vivo model. Overall results indicated that the beneficial effect related to porphyrins on psoriasis can be related to the decreasing of keratinocyte viability. Furthermore, some of the cationic porphyrins studied appeared as candidates to be utilized as photosensitizers for psoriasis treatment.

Assuntos

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OBJECTIVE AND BACKGROUND: The aim of this in vitro study was to compare the efficiency of a photodynamic therapy (PDT) technique employing rose bengal (RB) and methylene blue (MB) as photosensitizers (PSs) to reduce the viability of Enterococcus faecalis, a well-known pathogen found in root canal systems. Currently, in several clinical applications, including in the field of endodontics, MB is employed in association with a red laser source for the photoinactivation of pathogenic bacteria. METHODS: In this study, MB was used at 0.01% (31.2 mol/L) in association with a red (660 nm) laser as the excitation source in the MB group (MBG). Alternatively, the same test was performed with RB (25 mol/L) that was associated with a green (532 nm) light laser source in the RB group (RBG). A saline solution (0.9%) was used in the control group. The colony-forming units per milliliter (CFU/mL) were calculated after 24 h of incubation at 37°C, and the statistical analysis was performed using ANOVA. RESULTS: The results showed a significant reduction in the CFU/mL in the RBG group (0.12 × 108) compared with the control (2.82 × 108) and MBG groups (2.66 × 108). For the concentration and laser intensity employed in the experiments, the MBG group repeatedly showed no significant reduction in bacterial counts compared with the control. Therefore, the best result regarding the reduction of E. faecalis viable cells was obtained with RB as the PS. CONCLUSIONS: PDT may be improved if RB is used in association with a green light laser source for the inactivation of E. faecalis.

Assuntos

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BACKGROUND: This paper introduces a new nanoformulation of 5-aminolevulinic acid (nano-ALA) as well as a novel quantitative approach towards evaluating field cancerization for actinic keratosis and/or skin photodamage. In this pilot study, we evaluated field cancerization using nano-ALA and methyl aminolevulinate (MAL), the latter being commercialized as Metvix(®). METHODS AND RESULTS: Photodynamic therapy was used for the treatment of patients with selected skin lesions, whereas the fluorescence of the corresponding photosensitizer was used to evaluate the time evolution of field cancerization in a quantitative way. Field cancerization was quantified using newly developed color image segmentation software. Using photodynamic therapy as the precancer skin treatment and the approach introduced herein for evaluation of fluorescent area, we found that the half-life of field cancerization reduction was 43.3 days and 34.3 days for nano-ALA and MAL, respectively. We also found that nano-ALA targeted about 45% more skin lesion areas than MAL. Further, we found the mean reduction in area of skin field cancerization was about 10% greater for nano-ALA than for MAL. CONCLUSION: Although preliminary, our findings indicate that the efficacy of nano-ALA in treating skin field cancerization is higher than that of MAL.