RESUMEN

Phytopathogenic fungi significantly threaten global food security, causing substantial yield and quality losses. Sustainable solutions are urgently needed to combat these agricultural pathogens. This study explored the potential of silver (Ag), copper (Cu), and combined Ag/Cu nanoparticles capped with aminolevulinic acid (ALA) as antifungal agents. The nanoparticles (ALAAg, ALACu, and ALAAgCu) were synthesized via photoreduction and characterized using various techniques (UV-Vis, TEM, XRD, Zeta potential). Their antifungal activity against four key plant pathogens (Alternaria grandis, Colletotrichum truncatum, Corynespora cassiicola, and Fusarium oxysporum) was evaluated using poisoned food techniques. Notably, ALAAgCuNPs demonstrated superior antifungal activity compared to a conventional fungicide against two fungal strains. Even at lower concentrations, ALAAgCuNPs exhibited fungistatic effects comparable to those of the control. These promising results suggest the potential of ALAAgCu NPs as a broad-spectrum, potentially eco-friendly alternative for fungal control in plants and seeds. This approach is crucial for ensuring crop health, harvest quality, and food safety.

Asunto(s)

RESUMEN

Heme enzyme dysfunction causes a group of diseases called porphyrias. Particularly, a decrease in porphobilinogen deaminase, involved in the third step of heme biosynthesis, leads to acute intermittent porphyria (AIP). Considering our previous works demonstrating the multiplicity of brain metabolisms affected by porphyrinogenic agents, this study aimed to elucidate whether they cause any alteration on the mitochondrial respiratory chain. The activities of respiratory chain complexes (I to IV) were measured in encephalon mitochondria of CF1 male mice receiving volatile anesthetics: isoflurane (2 mL/kg) and sevoflurane (1.5 mL/kg), ethanol (30%), allylisopropylacetamide (AIA) (350 mg/kg), and barbital (167 mg/kg). Moreover, they were compared versus animals with pathological levels of 5-aminolevulinic acid (ALA, 40 mg/kg). Complex I-III activity was induced by isoflurane and decreased by AIA, ethanol, and ALA. Complex II-III activity was increased by sevoflurane and decreased by isoflurane and AIA. Complex II activity was increased by sevoflurane and barbital and decreased by AIA, ethanol, and ALA. Complex IV activity was increased by barbital and ALA and decreased by sevoflurane. The damage to the respiratory chain by ALA could be reflecting the pathophysiological condition of patients with AIP. Better understanding the broad effect of porphyrinogenic drugs and the mechanisms acting on the onset of AIP is vital in translational medicine.

RESUMEN

Introducción: La fotomarcación es una técnica no invasiva que consiste en la aplicación de un fotosensibilizador y la posterior visualización con lampara de Wood para determinar los márgenes de cáncer de piel no melanoma. Esto podría ser de utilidad en conjunto con la cirugía micrográfica de Mohs, al definir de manera más precisa los márgenes histológicos tumorales. Objetivo: Comparar los límites tumorales entre la demarcación clínica, la dermatoscópica y la demarcación con ALA en carcinomas cutáneos, y corroborarlos con el defecto quirúrgico obtenido por la CMM. Método: Estudio observacional, descriptivo y prospectivo. Se compararon las áreas tumorales de cáncer de piel no melanoma observadas por clínica, dermatoscopía, fotomarcación y defecto quirúrgico final. Resultados: El promedio del área clínica fue 1,77 cm2 (DE 0,55), el promedio de área dermatoscópica fue 1,93 cm2 (DE 0,55), el promedio del área por fotomarcación fue 2,14 cm2 (DE 0,55) y el promedio del área del defecto quirúrgico final fue 4,41 cm2 (DE 1,12). Conclusiones: No se logró comprobar que la fotomarcación tenga una ventaja estadísticamente significativa respecto a la marcación clínica y dermatoscópica. Se requieren más estudios para determinar el rol de esta técnica.

Introduction: Photomarking is a non-invasive technique that involves the application of a photosensitizer and subsequent visualization with a Wood's lamp to determine the margins of non-melanoma skin cancer. This could be useful in conjunction with Mohs micrographic surgery by more precisely defining the histological tumor margins. Objective: To compare the tumor limits between clinical demarcation, dermatoscopic demarcation, and ALA demarcation in cutaneous carcinomas, and corroborate them with the surgical defect obtained by MMS. Method: Observational, descriptive, and prospective study. The tumor areas of non-melanoma skin cancer observed by clinic, dermatoscopy, photomarking, and final surgical defect were compared. Results: The average clinical area was 1,77 cm2 (SD 0.55), the average dermatoscopic area was 1,93 cm2 (SD 0,55), the average area by photomarking was 2,14 cm2 (SD 0,55), and the average area of the final surgical defect was 4,41 cm2 (SD 1,12). Conclusions: It was not possible to demonstrate that photomapping provides a statistically significant advantage over clinical and dermatoscopic marking. Further studies are needed to determine the role of this technique.

Introdução: A fotomarcação é uma técnica não invasiva que envolve a aplicação de um fotossensibilizador e a subsequente visualização com lâmpada de Wood para determinar as margens do câncer de pele não melanoma. Isso poderia ser útil em conjunto com a cirurgia micrográfica de Mohs ao definir de forma mais precisa as margens histológicas tumorais. Objetivo: Comparar os limites tumorais entre a demarcação clínica, a demarcação dermatoscópica e a demarcação com ALA em carcinomas cutâneos, e corroborá-los com o defeito cirúrgico obtido pela CMM. Método: Estudo observacional, descritivo e prospectivo. Foram comparadas as áreas tumorais de câncer de pele não melanoma observadas por clínica, dermatoscopia, fotomarcação e defeito cirúrgico final. Resultados: A média da área clínica foi de 1,77 cm2 (DP 0,55), a média da área dermatoscópica foi de 1,93 cm2 (DP 0,55), a média da área por fotomarcação foi de 2,14 cm2 (DP 0,55) e a média da área do defeito cirúrgico final foi de 4,41 cm2 (DP 1,12). Conclusões: Não foi possível comprovar que a fotomarcação tenha uma vantagem estatisticamente significativa em relação à marcação clínica e dermatoscópica. Mais estudos são necessários para determinar o papel dessa técnica.

Asunto(s)

RESUMEN

BACKGROUND: Porphyrias are a rare group of disease due to inherited defects of heme synthesis with important systemic manifestations and great burden of disease for patients and families due to the exceptional course of disease with disabling chronic symptoms interposed by life-threatening acute attacks. Unfortunately, the porphyrias are usually underrecognized reflecting a lack of medical and disease awareness as well as few studies about natural history in large cohorts of patients. The main aim of this article is present consistent data about natural history and burden of disease in a large Brazilian cohort. METHODS: We conducted a national cross-sectional registry with retrospective clinical data of Brazilian patients with porphyria collected with Brazilian patients Association with Porphyria in collaboration with a tertiary care center for rare diseases. RESULTS: A cohort of 172 patients was analyzed in which 148 (86%) patients had the diagnosis of acute hepatic porphyria [AHP] that needed a mean of 62.04 medical visits and 9.6 years to achieve a definitive diagnosis. About AHP cohort, the most common first clinical manifestation were abdominal pain in 77 (52%) patients and acute muscle weakness in 23 (15.5%) with 73 (49.3%) patients presenting only one attack during disease course and 37 (25%) exhibiting 4 or more attacks in the last year. Of note, 105 patients with AHP reported chronic manifestations and the scores for quality of life are lower when compared with general healthy population. CONCLUSIONS: Brazilian patients with AHP had a higher prevalence of chronic disabling manifestations and a poor quality of life like other cohorts and a higher proportion of patients with recurrent attacks than previously reported.

Asunto(s)

RESUMEN

5-aminolevulinic acid (5-ALA) is the first precursor of the heme biosynthesis pathway, accumulated in acute intermittent porphyria (AIP), an inherited metabolic disease characterized by porphobilinogen deaminase deficiency. An increased incidence of hepatocellular carcinoma (HCC) has been reported as a long-term manifestation in symptomatic AIP patients. 5-ALA is an α-aminoketone prone to oxidation, yielding reactive oxygen species and 4,5-dioxovaleric acid. A high concentration of 5-ALA presents deleterious pro-oxidant potential. It can induce apoptosis, DNA damage, mitochondrial dysfunction, and altered expression of carcinogenesis-related proteins. Several hypotheses of the increased risk of HCC rely on the harmful effect of elevated 5-ALA in the liver of AIP patients, which could promote a pro-carcinogenic environment. We investigated the global transcriptional changes and perturbed molecular pathways in HepG2 cells following exposure to 5-ALA 25 mM for 2 h and 24 h using DNA microarray. Distinct transcriptome profiles were observed. 5-ALA '25 mM-2h' upregulated 10 genes associated with oxidative stress response and carcinogenesis. Enrichment analysis of differentially expressed genes by KEGG, Reactome, MetaCore™, and Gene Ontology, showed that 5-ALA '25 mM-24h' enriched pathways involved in drug detoxification, oxidative stress, DNA damage, cell death/survival, cell cycle, and mitochondria dysfunction corroborating the pro-oxidant properties of 5-ALA. Furthermore, our results disclosed other possible processes such as senescence, immune responses, endoplasmic reticulum stress, and also some putative effectors, such as sequestosome, osteopontin, and lon peptidase 1. This study provided additional knowledge about molecular mechanisms of 5-ALA toxicity which is essential to a deeper understanding of AIP and HCC pathophysiology. Furthermore, our findings can contribute to improving the efficacy of current therapies and the development of novel biomarkers and targets for diagnosis, prognosis, and therapeutic strategies for AHP/AIP and associated HCC.

Asunto(s)

RESUMEN

5-aminolevulinic acid (5-ALA) is the first precursor of the heme biosynthesis pathway, accumulated in acute intermittent porphyria (AIP), an inherited metabolic disease characterized by porphobilinogen deaminase deficiency. An increased incidence of hepatocellular carcinoma (HCC) has been reported as a long-term manifestation in symptomatic AIP patients. 5-ALA is an α-aminoketone prone to oxidation, yielding reactive oxygen species and 4,5-dioxovaleric acid. A high concentration of 5-ALA presents deleterious pro-oxidant potential. It can induce apoptosis, DNA damage, mitochondrial dysfunction, and altered expression of carcinogenesis-related proteins. Several hypotheses of the increased risk of HCC rely on the harmful effect of elevated 5-ALA in the liver of AIP patients, which could promote a pro-carcinogenic environment. We investigated the global transcriptional changes and perturbed molecular pathways in HepG2 cells following exposure to 5-ALA 25 mM for 2 h and 24 h using DNA microarray. Distinct transcriptome profiles were observed. 5-ALA ’25 mM-2h′ upregulated 10 genes associated with oxidative stress response and carcinogenesis. Enrichment analysis of differentially expressed genes by KEGG, Reactome, MetaCore™, and Gene Ontology, showed that 5-ALA ‘25 mM-24h’ enriched pathways involved in drug detoxification, oxidative stress, DNA damage, cell death/survival, cell cycle, and mitochondria dysfunction corroborating the pro-oxidant properties of 5-ALA. Furthermore, our results disclosed other possible processes such as senescence, immune responses, endoplasmic reticulum stress, and also some putative effectors, such as sequestosome, osteopontin, and lon peptidase 1. This study provided additional knowledge about molecular mechanisms of 5-ALA toxicity which is essential to a deeper understanding of AIP and HCC pathophysiology. Furthermore, our findings can contribute to improving the efficacy of current therapies and the development of novel biomarkers and targets for diagnosis, prognosis, and therapeutic strategies for AHP/AIP and associated HCC.

RESUMEN

One of the most widely used molecules used for photodynamic therapy (PDT) is 5-aminolevulinic acid (5-ALA), a precursor in the synthesis of tetrapyrroles such as chlorophyll and heme. The 5-ALA skin permeation is considerably reduced due to its hydrophilic characteristics, decreasing its local bioavailability and therapeutic effect. For this reason, five different systems containing polymeric particles of poly [D, L-lactic-co-glycolic acid (PLGA)] were developed to encapsulate 5-ALA based on single and double emulsions methodology. All systems were standardized (according to the volume of reagents and mass of pharmaceutical ingredients) and compared in terms of laboratory scaling up, particle formation and stability over time. UV-VIS spectroscopy revealed that particle absorption/adsorption of 5-ALA was dependent on the method of synthesis. Different size distribution was observed by DLS and NTA techniques, revealing that 5-ALA increased the particle size. The contact angle evaluation showed that the system hydrophobicity was dependent on the surfactant and the 5-ALA contribution. The FTIR results indicated that the type of emulsion influenced the particle formation, as well as allowing PEG functionalization and interaction with 5-ALA. According to the 1H-NMR results, the 5-ALA reduced the T1 values of polyvinyl alcohol (PVA) and PLGA in the double emulsion systems due to the decrease in molecular packing in the hydrophobic region. The results indicated that the system formed by single emulsion containing the combination PVA-PEG presented greater stability with less influence from 5-ALA. This system is a promising candidate to successfully encapsulate 5-ALA and achieve good performance and specificity for in vitro skin cancer treatment.

Asunto(s)

RESUMEN

Objetivo: La leucoplasia oral es el desorden maligno de la mucosa bucal más prevalente a nivel global y su manejo clínico sigue siendo un desafío. Se llevó a cabo una revisión sistemática para determinar la eficacia clínica de la terapia fotodinámica mediada por ácido 5-aminolevulínico tópico como una alternativa de quimio-prevención para las diferen- tes formas clínicas de la leucoplasia oral. Materiales y métodos: Empleando términos MeSH, se realizó una búsqueda exhaustiva en diferentes bases digi- tales de ensayos clínicos publicados en inglés en los últimos 30 años acerca del uso de la terapia fotodinámica mediada por ácido 5-aminolevulínico tópico como fotosensibilizador, y radiación láser de baja intensidad o luz LED como posibles fuentes de iluminación. Resultados: La revisión sistematizada que aplicó la guía PRISMA mostró una eficacia del 88,6% para este modo de fototerapia en el manejo de leucoplasias orales, con un 60,7% de respuesta completa y 27,9% de respuesta parcial. Además, el tamaño de efecto fue mayor para las formas clíni- cas homogéneas con cambios displásicos, independientemen- te del tipo de fuente de luz. La ausencia de respuesta fue del 11,4%, pero la evidencia empleada en este análisis fue mo- derada. Conclusión: La terapia fotodinámica mediada por áci- do 5-aminolevulínico tópico parece ser una alternativa útil en el manejo onco-preventivo de lesiones de leucoplasia oral. Sin embargo, es recomendable ejecutar ensayos clínicos controla- dos y aleatorizados con metodologías homogéneas que per- mitan generar un meta-análisis con un alto nivel de evidencia

Aim: Oral leukoplakia is globally the most prevalent ma- lignant disorder of the oral mucosa and its clinical manage- ment remains a challenge. A systematic review was carried out to determine the clinical efficacy of photodynamic therapy mediated by topical 5-aminolevulinic acid as an alternative for chemoprevention in the different clinical forms of oral leu- koplakia. Materials and methods: Using MeSH terms, an ex- haustive search was carried out in different digital databases of clinical trials published in English in the last 30 years on the use of photodynamic therapy mediated by topical 5-ami- nolevulinic acid as a photosensitizer, and low-intensity laser radiation or LED light as possible lighting sources. Results: The systematized review using PRISMA guide- lines showed an efficacy of 88.6% for this mode of photother- apy in the management of oral leukoplakias, based on 60.7% of complete response and 27.9% of partial response. In addi- tion, the effect size was larger in homogeneous clinical forms with dysplastic changes, regardless of the type of light source. There was an 11.4% of absence of response, but the evidence used in this analysis was moderate. Conclusion: Photodynamic therapy mediated by topical 5-aminolevulinic acid seems to be a useful alternative in the onco-preventive management of oral leukoplakia lesions. However, it is recommendable to perform controlled and ran- domized clinical trials with homogeneous methodologies that allow the generation of a meta-analysis with a high level of evidence (AU)

Asunto(s)

RESUMEN

Photodynamic therapy (PDT) is a non-surgical treatment that has been approved for its human medical use in many cancers. PDT involves the interaction of a photosensitizer (PS) with light. The amino acid 5- aminolevulinic acid (ALA) can be used as a pro-PS, leading to the synthesis of Protoporphyrin IX. Hydrogen sulfide (H2S) is an endogenously produced gas that belongs to the gasotransmitter family, which can diffuse through biological membranes and have relevant physiological effects such as cardiovascular functions, vasodilatation, inflammation, cell cycle and neuro-modulation. It was also proposed to have cytoprotective effects. We aimed to study the modulatory effects of H2S on ALAPDT in the mammary adenocarcinoma cell line LM2. Exposure of the cells to NaHS (donor of H2S) in concentrations up to 10 mM impaired the response to ALA-PDT in a dose-dependent manner. The addition of 3 doses of NaHS showed the highest effect. This decreased response to the photodynamic treatment was correlated to an increase in the GSH levels, catalase activity, a dose dependent reduction of PpIX and increased intracellular ALA, decreased levels of oxidized proteins and a decrease of PDT-induced ROS. NaHS also reduced the levels of singlet oxygen in an in vitro assay. H2S also protected other cells of different origins against PDT mediated by ALA and other PSs. These results suggest that H2S has a role in the modulation of the redox state of the cells, and thus impairs the response to ALA-PDT through multifactor pathways. These findings could contribute to developing new strategies to improve the effectiveness of PDT particularly mediated by ALA or other ROS-related treatments.

Asunto(s)

RESUMEN

RESUMEN Las porfirias son trastornos metabólicos hereditarios causados por deficiencias enzimáticas de la biosíntesis del grupo HEM. Con presentación en distintos grupos de edades, más común en infancia y tercera a cuarta década de la vida, se caracterizan por elevación de porfirinas, y manifestaciones variadas cutáneas y neuro viscerales. Describimos una serie de 3 casos de pacientes femeninas en tercera década de la vida con dolor abdominal severo e inespecífico y una amplia gama de manifestaciones clínicas con sus complicaciones a corto y largo plazo en quienes se diagnosticó porfiria aguda intermitente (PAI). Se hará revisión en la literatura para aportar al reconocimiento temprano de estas condiciones e instaurar de forma temprana el manejo específico e impactar en desenlaces irreversibles.

ABSTRACT Porphyrias are inherited metabolic disorders caused by enzymatic deficiencies of HEM group biosynthesis. Most common in childhood at the third and fourth decade of life. They are characterized by increased levels of porphyrins, and various cutaneous, neurological, and visceral manifestations. We describe a series of 3 cases of female patients in the third decade of life with abdominal pain and a wide range of clinical manifestations and short and long-term complications. Our review contributes to the early recognition of these diseases to establish early specific managements to impact on irreversible outcomes.

RESUMEN

Photodynamic therapy (PDT) is an effective procedure for the treatment of lesions diseases based on the selectivity of a photosensitising compound with the ability to accumulate in the target cell. Atherosclerotic plaque is a suitable target for PDT because of the preferential accumulation of photosensitisers in atherosclerotic plaques. Dendrimers are hyperbranched polymers conjugated to drugs. The dendrimers of ALA hold ester bonds that inside the cells are cleaved and release ALA, yielding PpIX production. The dendrimer 6m-ALA was chosen to perform this study since in previous studies it induced the highest porphyrin macrophage: endothelial cell ratio (Rodriguez et al. in Photochem Photobiol Sci 14:1617-1627, 2015). We transformed Raw 264.7 macrophages to foam cells by exposure to oxidised LDLs, and we employed a co-culture model of HMEC-1 endothelial cells and foam cells to study the affinity of ALA dendrimers for the foam cells. In this work it was proposed an in vitro model of atheromatous plaque, the aim was to study the selectivity of an ALA dendrimer for the foam cells as compared to the endothelial cells in a co-culture system and the type of cell death triggered by the photodynamic treatment. The ALA dendrimer 6m-ALA showed selectivity PDT response for foam cells against endothelial cells. A light dose of 1 J/cm2 eliminate foam cells, whereas less than 50% of HMEC-1 is killed, and apoptosis cell death is involved in this process, and no necrosis is present. We propose the use of ALA dendrimers as pro-photosensitisers to be employed in photoangioplasty to aid in the treatment of obstructive cardiovascular diseases, and these molecules can also be employed as a theranostic agent.

Asunto(s)

RESUMEN

One important limitation of topical photodynamic therapy (PDT) is the limited tissue penetration of precursors. Microneedles (MNs) are minimally invasive devices used to promote intradermal drug delivery. Dissolving MNs contain drug-associated to polymer blends, dissolving after insertion into skin, allowing drug release. This study comprises development and characterization of a pyramidal model of dissolving MNs (500 µm) prepared with 5% wt/wt aminolevulinic acid and 20% wt/wt Gantrez AN-139 in aqueous blend. Protoporphyrin IX formation and distribution were evaluated in tumor mice model by using fluorescence widefield imaging, spectroscopy, and confocal microscopy. MNs demonstrated excellent mechanical resistance penetrating about 250 µm with minor size alteration in vitro, and fluorescence intensity was 5-times higher at 0.5 mm on average compared to cream in vivo (being 10 ± 5 a.u. for MNs and 2.4 ± 0.8 a.u. for cream). Dissolving MNs have overcome topical cream application, being extremely promising especially for thicker skin lesions treatment using PDT.

Asunto(s)

RESUMEN

Glioblastoma is the most severe form of brain cancer. Despite multimodal therapy combining surgery, radiotherapy and chemotherapy, prognosis of patients is dismal. It has been observed that the surgical resection guided by photosensitizer fluorescence followed by photodynamic therapy (PDT) prolongs the average survival in patients with glioblastoma. The main problem with all oncological treatments, including PDT, is the presence of resistant cells. The objective of this study was to isolate and perform an initial characterization of human glioblastoma cells resistant to PDT employing methyl-5-aminolevulinic acid. We obtained resistant cells from the T98 G cell line. Resistant populations accumulated less photosensitizer, formed spheroids of higher number of cells, had higher tumorigenic capacity, and expressed higher mRNA levels of fibroblastic growth factor receptor (FGFR), epidermal growth factor receptor (EGFR) and ß-platelet-derived growth factor receptor (ßPDGFR) than parental cells. The studies of glioblastoma resistance to PDT would help to better understand the causes of tumor recurrence after PDT and to develop new therapeutic proposals in this field of oncology.

Asunto(s)

RESUMEN

Metastasis to the calvarium with direct pericranium or dural infiltration may be treated with radical surgical removal in selected cases. We describe microsurgical resection of calvarial metastases with fluorescence-guided technique using 5-aminolevulinic acid (5-ALA) in two female patients with breast cancer. Fluorescence findings were positive in both cases. Margins in the scalp and dural layer were 5-ALA negative at the end of surgical removal. Intraoperative pathology was performed in all cases to confirm if oncological limits were free of disease. One case was 5-ALA positive in the outer layer of the dura-mater and another in the pericranium. At the end of the removal in both cases, the surgicalmargins were 5-ALA fluorescence-free. Intraoperative pathology confirmed oncological limits of the resection. 5-aminolevulinic acid fluorescence-guided surgery for calvarial metastases with pericranium and/or dural extension seems to be a safe and reliable method to aid the surgical margins for complete removal, possibly delaying or avoiding adjuvant irradiation for progression control.

Asunto(s)

RESUMEN

Bacterial photodynamic inactivation (PDI) employing endogenous production of porphyrins from 5-aminolevulinic acid (ALA) - named ALA-PDI-, is a new promising tool to achieve bacteria control in non-spread infections. The technique combines the action of the porphyrins acting as photosensitisers with light, to produce reactive oxygen species to target the pathogen. To date, some clinical applications of ALA-PDI have been reported although variable responses ranging from total eradication to absence of photokilling were found. ALA-PDI conducted at suboptimal conditions may lead to misleading results and the complexity of haem synthesis in bacteria hinders the optimization of the treatment. The present work aimed to gain insight on the variables affecting ALA-PDI in Gram-positives and Gram-negatives bacteria growing on planktonic and biofilm cultures and to correlate the degree of the response with the amount and type of porphyrin synthesised. Staphylococcus epidermidis and Escherichia coli clinical isolates and Pseudomonas aeruginosa ATCC27853 and Staphylococcus aureus ATCC25923 strains were utilised, and the optimal conditions of concentration and time exposure of ALA, and light dose were set. In both Gram-positive species analysed, a peak of porphyrin synthesis was observed at 1-2 mM ALA in biofilm and planktonic cultures, which fairly correlated with the decrease in the number of CFU after PDI (5 to 7 logs) and porphyrin content was in the same order of magnitude. In addition, ALA-PDI was similarly effective for planktonic and biofilm S. aureus cultures, and more effective in S. epidermidis planktonic cultures at low light doses. Beyond a certain light dose, it was not possible to achieve further photosensitization. Similarly, a plateau of cell death was attained at a certain ALA incubation time. Accumulation of hydrophilic porphyrins at longer incubation periods was observed. The proportion of porphyrins changed as a function of ALA concentration and incubation time in the Gram-positive bacteria, though we did not find a clear correlation between the porphyrin type and PDI response. As a salient feature was the presence of isococroporphyrin isoforms in both Gram-positive and Gram-negative bacteria. Gram-negative bacteria were quite refractory to the treatment: P. aeruginosa was slightly inactivated (4-logs reduction) at 40 mM ALA, whereas E. coli was not inactivated at all. These species accumulated high ALA quantities and the amount of porphyrins did not correlate with the degree of photoinactivation. Our microscopy studies show that porphyrins are not located in the envelopes of Gram-negative bacteria, reinforcing the hypothesis that endogenous porphyrins fail to attack these structures.

Asunto(s)

RESUMEN

Aim: Nano-5-aminolevulic acid (NanoALA)-mediated photodynamic therapy (PDT), an oil-in-water polymeric nanoemulsion of ALA, was evaluated in a murine model of breast cancer. Materials & methods: Analysis of ALA-derived protoporphyrin IX production and acute toxicity test, biocompatibility and treatment efficacy, and long-term effect of NanoALA-PDT on tumor progression were performed. Results: The nanoformulation favored the prodrug uptake by tumor cells in a shorter time (1.5 h). As a result, the adverse effects were negligible and the response rates for primary mammary tumor control were significantly improved. Tumor progression was slower after NanoALA-PDT treatment, providing longer survival. Conclusion: NanoALA is a good proactive drug candidate for PDT against cancer potentially applied as adjuvant/neoadjuvant intervention strategy for breast cancer.

Asunto(s)

RESUMEN

The present research describes the synthesis of cadmium sulfide (CdS) nanoparticles from Escherichia coli under the influence of bacterial enzyme sulphate reductase and study on their cytotoxicity for applications in cancer therapy. Escherichia coli cells were used to synthesize CdS nanoparticles under different concentrations of cadmium chloride and sodium sulfide. The morphology of the nanoparticles was analysed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) was used for elemental analysis of nanoparticles. Fourier-transform infrared spectroscopy analysis (FTIR) was performed to assess the functional groups of the nanoparticles. Crystalline nature of nanoparticles was assessed using powder X-ray diffraction (XRD). Antibacterial studies of CdS nanoparticles were carried out on foodborne pathogens and cytotoxicity studies were carried out on Mus musculus skin melanoma (B16F10) and human epidermoid carcinoma (A431) cell lines. CdS nanoparticle showed more cytotoxic effect on cancer cells compared with standard 5-aminolevulinic acid (5-ALA). The Escherichia coli-synthesized CdS nanoparticles showed highest zone of inhibition in the ratio 4:1 of cadmium chloride and sodium sulfide on all tested bacterial strains. The nanoparticles were also tested for haemolytic activity on RBC cells, which exhibited lower cytotoxicity than sodium dodecyl sulphate which was used as positive control. The cytotoxicity of CdS nanoparticles assessed on A431 cells showed an inhibition of 81.53% at 100 µM concentration while the cytotoxicity assessed on B16F10 cells showed an inhibition of 75.71% at 200 µM concentration which was much efficient than 5-ALA which showed an inhibition of 31.95% at a concentration against B16F10 cells and 33.45% against A431 cells at a concentration of 1 mM. Cadmium sulfide nanoparticles were thus found to be highly toxic on cancer cells compare with standard anticancerous drug 5-ALA.

Asunto(s)

RESUMEN

The objective of this study was to evaluate and compare the clinical response to PDT (Photodynamic Therapy) in field cancerization using two aminolevulinate derivatives. Forty patients with multiple actinic keratosis (AK) on forearms and hands scattered received two sessions of ALA and MAL-PDT at 630 nm (36 J/cm2). The AK clearance rate was 72 % for both drugs with a significant decrease in AK observed clinically (p < 00,001). Clinical improvement in field cancerization using two aminolevulinate derivatives in PDT is proven with no significant difference in the efficacy of drugs.

Asunto(s)

RESUMEN

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 administered δ-ALA on E. faecalis in planktonic and biofilm forms was confirmed by spectrofluorometry. The irradiation of PpIX with an argon laser produced an antibacterial effect on E. faecalis in planktonic and biofilm form, even without biofilm disruption, at a concentration of 40 µg/mL and 80 µg/mL of δ-ALA, respectively. The exogenous administration of δ-ALA in combination with laser irradiation on planktonic and biofilm forms of E. faecalis produces an effective antibacterial effect as complement or alternative to pharmacological therapies

Asunto(s)

RESUMEN

Objective: In this study, we evaluated the effectiveness of photodynamic therapy (PDT) for the treatment of experimental cutaneous leishmaniasis (CL) and the profile of macrophages activation markers. Background: Leishmaniasis is an infectious disease caused by parasites of the genus Leishmania. CL is caused by Leishmania major in the old world and by Leishmania braziliensis in the Americas. Considering the targeted organs, PDT may constitute a valuable therapeutic intervention. Macrophages are the host cells of Leishmania in mammals and may be classified into type M1 or M2 depending on the pattern of activation. Methods: BALB/c mice were infected in the foot pad with 1 × 106 amastigotes of L. braziliensis and treated with 5-aminolevulinic acid (5-ALA), visible light, or 5-ALA-PDT. The ex vivo mRNA expression levels of interleukin-10, tumor necrosis factor-α (TNF-α), arginase-1, heme oxygenase ( Hmox), and induced nitric oxide synthase (iNOS) were quantities as markers of macrophage activation with distinct ability to kill intracellular parasite. Results: The parasite load decreased significantly in the group treated with PDT compared with the other groups. The iNOS relative mRNA was higher in the group treated with PDT and light only compared with the group without treatment, whereas iNOS/arginase ratio was significantly higher only in the PDT group. The expression of TNF-α was significantly higher in 5-ALA and light compared with PDT and control group. No significant difference was observed in the expression of the other markers evaluated. Conclusions: Both, light and 5-ALA-PDT were able to upregulate iNOS expression only; 5-ALA-PDT was able to reduce parasite burden. The increase in the iNOS levels suggests it might participate in the antimicrobial mechanisms triggered by 5-ALA-PDT; although parasite death mechanism was not completely clarified, the results presented in this study suggest that macrophage activation may contribute to parasite control.

Asunto(s)