Sonophotodynamic inactivation of Pseudomonas aeruginosa biofilm mediated by curcumin.

The inactivation of Pseudomonas aeruginosa biofilm is a major challenge, as biofilms are less responsive to conventional treatments and responsible for persistent infections. This has led to the investigation of alternative approaches for biofilm control such as photodynamic (PDI) and sonodynamic (SDI) inactivation. The combination of them, known as Sonophotodynamic Inactivation (SPDI), has improved the effectiveness of the process. Curcumin, a well-established photosensitizer, has been identified as a potential sonosensitizer. This study evaluated the most effective combination for SPDI against P. aeruginosa biofilms in vitro, varying curcumin concentrations and ultrasound intensities. The results indicated that the inactivation was directly proportional to the curcumin concentration. Using curcumin 120 µM and 3.0 W.cm-2 of ultrasound intensity, SPDI demonstrated the highest and the best synergistic results, equivalent to 6.9 ± 2.1 logs of reduction. PDI reduced 0.7 ± 0.9 log and SDI had no effect. In conclusion, SPDI with curcumin is a promising approach for biofilm inactivation.

Effects of photobiomodulation on the redox state of healthy and cancer cells.

Photobiomodulation therapy (PBMT) uses light to stimulate cells. The molecular basis of the effects of PBMT is being unveiled, but it is stated that the cytochrome-c oxidase enzyme in mitochondria, a photon acceptor of PBMT, contributes to an increase in ATP production and modulates the reduction and oxidation of electron carriers NADH and FAD. Since its effects are not fully understood, PBMT is not used on tumors. Thus, it is interesting to investigate if its effects correlate to mitochondrial metabolism and if so, how it could be linked to the optical redox ratio (ORR), defined as the ratio of FAD/(NADH + FAD) fluorescences. To that end, fibroblasts (HDFn cell line) and oral squamous cell carcinoma (SCC-25 cell line) were irradiated with a light source of 780 nm and a total dose of 5 J/cm2, and imaged by optical microscopy. PBMT down-regulated the SCC-25 ORR by 10%. Furthermore, PBMT led to an increase in ROS and ATP production in carcinoma cells after 4 h, while fibroblasts only had a modest ATP increase 6 h after irradiation. Cell lines did not show distinct cell cycle profiles, as both had an increase in G2/M cells. This study indicates that PBMT decreases the redox state of oral cancer by possibly increasing glycolysis and affects normal and tumor cells through distinct pathways. To our knowledge, this is the first study that investigated the effects of PBMT on mitochondrial metabolism from the initiation of the cascade to DNA replication. This is an essential step in the investigation of the mechanism of action of PBMT in an effort to avoid misinterpretations of a variety of combined protocols.

Avaliação da redução da carga viral do papilomavírus humano por meio da captura híbrida após terapia fotodinâmica em lesões intraepiteliais cervicais alto grau / Load reduction assessment human papillomavirus viral through hybrid capture after photodynamic therapy in injuries high grade cervical intraepithelial

Contexto e objetivo: No mundo, aproximadamente 20 milhões de mulheres encontram-se infectadas pelo papilomavírus humano (HPV). Esta infecção pode ser assintomática ou causar papilomas verrucosos benignos, neoplasias intraepiteliais cervicais (NICs) de baixo ou alto grau, carcinoma cervical, vaginal e anal. Os tratamentos atuais para as NICs ainda são muito invasivos e destrutivos. Sendo assim, existe a necessidade do desenvolvimento de modalidades menos agressivas. A terapia fotodinâmica (TFD) atende a esses pedidos, induzindo a morte seletiva de células infectadas pelo vírus. Este artigo tem o objetivo de analisar a redução da carga viral de HPV em pacientes com lesões intraepiteliais cervicais de alto grau (LIEAG) antes e após a TFD. Métodos: Foram incluídas 28 pacientes portadoras de NICs de alto grau que realizaram tratamento com 2,5 g de creme contendo o pró-fármaco ácido 5-metil aminolevulínico (MAL) a 20%, por aproximadamente 10 horas, com posterior aplicação da luz de LED com comprimento de onda de 630 nm e irradiância de 120 mW/cm2, por 25 minutos, entregando uma dose total de 180 J/cm2, em duas sessões. As pacientes foram avaliadas por meio de captura híbrida antes e após a TFD. Resultados: Após análise criteriosa, observou-se redução significativa da carga viral dos HPVs de alta oncogenicidade após a TFD (P = 0,0334) nas pacientes com LIEAG. O mesmo não foi observado em relação aos HPVs de baixo grau oncogênico (P = 0,4038). Conclusão: A TFD parece ser eficaz e promissora na diminuição da carga viral em pacientes com LIEAG induzidos por subtipos de HPV de alto grau oncogênico.

Strategies to Improve the Antimicrobial Efficacy of Photodynamic, Sonodynamic, and Sonophotodynamic Therapies.

BACKGROUND AND OBJECTIVES: This work evaluated antimicrobial photodynamic therapy (PDT), sonodynamic therapy (SDT), and the association of both therapies (sonophotodynamic therapy [SPDT]), mediated by curcumin (Cur) against Staphylococcus aureus biofilm. Next, additional strategies for these treatments were assessed. MATERIALS AND METHODS: S. aureus biofilms received PDT, SDT, and SPDT, mediated by Cur (80 µM), LED light (450 nm), and 1 MHz ultrasound. The same treatments were also performed adding a strategy: Cur with sodium dodecyl sulfate (SDS), Cur with potassium iodide (KI) or a pre-treatment with ultrasound. Cell viability was determined and biofilm architecture was evaluated under confocal microscopy. RESULTS: SPDT was more effective to inactivate the bacteria than PDT and SDT. SDS achieved the greatest viability reductions, followed by KI and ultrasound pre-treatment. Confocal images revealed biofilm disruption and a reduced number of cells in all treatments. However, SPDT exhibited a pronounced effect and it was greater using SDS. CONCLUSION: SPDT was more effective and additional strategies potentiated its effectiveness. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Photodynamic and Sonodynamic Therapy with Protoporphyrin IX: In Vitro and In Vivo Studies.

Sono-photodynamic therapy is a promising anticancer technique based on the combination of sonodynamic and photodynamic therapy to improve the cancer treatment effectiveness. This study was aimed at analyzing the effects of the sono-photodynamic (SPD) activity on protoporphyrin IX (PpIX) solution and PpIX-loaded rat liver. In vitro, PpIX 5 µM solutions were irradiated with light (635 nm, 30-50 mW/cm2), ultrasound (1 MHz, 1-2 W/cm2) and both. The PpIX absorption spectra recorded over exposure time revealed that the PpIX decay rate induced by SPD activity (combined irradiation) was approximately the sum of those induced by photodynamic and sonodynamic activity. In vivo, rats were intraperitoneally injected with 5-aminolevulinic acid at the dose of 500 mg/kg weight. After 3 h of injection, the PpIX-loaded livers were irradiated with light (635 nm, 180 ± 9 J/cm2), ultrasound (1.0 MHz, 770 ± 40 J/cm2) and both using a single probe capable of illuminating and sonicating the liver simultaneously. After 30 h, the liver damage induced by each protocol was analyzed histologically. It was found that a greater necrosis depth was induced by the SPD activity. These results suggest that the SPD activity could improve the PpIX decay rate and have greater scope than photodynamic or sonodynamic activity. Further studies should be performed to gain a better understanding of this protocol.

Susceptibility of Staphylococcus aureus to porphyrin-mediated photodynamic antimicrobial chemotherapy: an in vitro study.

The ability of Staphylococcus aureus to develop multidrug resistance is well documented, and the antibiotic resistance showed by an increasing number of bacteria has shown the need for alternative therapies to treat infections, photodynamic therapy (PDT) being a potential candidate. The aim of this study was to determine the effect of photodynamic therapy as a light-based bactericidal modality to eliminate Staphylococcus aureus. The study investigated a technique based on a combination of light and a photosensitizer that is capable of producing oxidative species to induce a cytotoxic effect. A Staphylococcus aureus suspension was exposed to a light emitting diode (LED) emitting at 628 nm, 14.6 mW/cm(2), and energy density of 20 J/cm(2), 40 J/cm(2), or 60 J/cm(2) in the presence of different porphyrin concentrations (Photogem). Three drug concentrations were employed: 12 microl/ml, 25 microl/ml, and 50 microl/ml. The treatment response was evaluated by the number of bacterial colony forming units (CFU) after light exposure. The results indicated that exposure to 60 J/cm(2) eliminated 100% (10 log(10) scales) of bacteria, on average. The best PDT response rate to eliminate Staphylococcus aureus was achieved with exposure to LED light in combination with the photosensitizer at concentrations ranging from 25 microl/ml to 50 microl/ml. These data suggest that PDT has the potential to eliminate Staphylococcus aureus in suspension and indicates the necessary drug concentration and light fluency.

Led enhancement in mitochondrial oxidative phosphorylation for hepatectomized rats

Recently, the LED (light emitting diode) developed by the Optics Group of IFSC-USP has been used instead of laser for the treatment of skin tumors by the PDT (Photodinamic Therapy) because of its low operational cost compared to the use of a laser. In this paper we investigate the effect of LED light on oxidative phosphorylation during liver regeneration after partial hepatectomy. Twenty-four male Wistar rats (250 g) were kept in identical housing units on a 12-hour light/12 hour dark cycle. The LED 10 group was exposed to LED at 638 nm (10 J/cm² for 3 minutes). Seventy percent partial hepatectomy was performed in the LED 10 and HPC (Partial Hepatectomy-Control). A sham-operated group (C) was used for control. Twenty four hours after the procedure, LED 10, HPC and control animals were sacrificed. Samples of liver tissue were used for the mitochondrial respiration assay. Statistical comparisons of the groups were performed by analysis of variance (ANOVA), followed by the Bonferroni post-test. Probability values less than 0.05 were considered to be statistically significant. the phosphorylation index (FI) for the LED 10 group was higher than that for the HPC group and for the sham group (p 005). The FI for the HPC group was higher than that for the sham group (p 005). The values of the ADP:O ratio for the three groups, which did not differ significantly from one another (p > 0.05). In the present study we noted an effective interaction between LED light and hepatic mitochondria, with an increased phosphorylation rate for the latter.

Efeitos do laser sobre a cirrose hepática

O presente estudo relata os efeitos da aplicação de LASER sobre fígados cirróticos de ratos Wistar. A cirrose hepática foi induzida através da ligadura do ducto biliar. Aproximadamente vinte e cinco dias após a cirurgia inicial, os animais foram submetidos à irradiação LASER com exposição hepática direta. O experimento compôs-se da análise morfométrica dos constituintes do fígado após 24 horas da irradiação. Os resultados revelaram maior proliferação vascular nos animais irradiados sem alteração dos demais componentes.