RESUMO
With the rapid development of nanotechnology, various functional nanomaterials have shown exciting potential in biomedical areas such as drug delivery, antitumor, and antibacterial therapy. These nanomaterials improve the stability and selectivity of loaded drugs, reduce drug-induced side effects, realize controlled and targeted drug release, and increase therapeutic efficacy. The increased resistance to antifungal microbicides in medical practice and their side effects stimulate interest in new therapies, such as Photodynamic Therapy (PDT), which do not generate resistance in microorganisms and effectively control the pathology. The present study aimed to evaluate, in vitro, the efficacy of photodynamic therapy on Candida albicans using 1,9-Dimethyl-Methylene Blue (DMMB) as photosensitizer, red LED (λ630), and nanoencapsulation of DMMB (RL-NPs/DMMB) using rhamnolipids produced by Pseudomonas aeruginosa to evaluate if there is better performance of DMMB + RL particles compared to DMMB alone via the characterization of DMMB + RL and colony forming count. The tests were carried out across six experimental groups (Control, DMMB, RL-NPs, RL-NPs/DMMB, PDT and PDT + RL-NPs/DMMB) using in the groups with nanoparticles, DMMB (750 ng/mL) encapsulated with rhamnolipids in a 1:1 ratio, the light source consisted of a prototype built with a set of red LEDs with an energy density of 20 J/cm2. The results showed that applying PDT combined with encapsulation (RL-NPs/DMMB) was a more practical approach to inhibit Candida albicans (2 log reduction) than conventional applications, with a possible clinical application protocol.
Assuntos
Candida albicans , Glicolipídeos , Azul de Metileno , Nanopartículas , Fotoquimioterapia , Fármacos Fotossensibilizantes , Pseudomonas aeruginosa , Candida albicans/efeitos dos fármacos , Glicolipídeos/química , Glicolipídeos/farmacologia , Azul de Metileno/química , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Nanopartículas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Antifúngicos/química , Antifúngicos/farmacologia , Composição de MedicamentosRESUMO
Orthodontic treatment involves the use of apparatuses that impairs oral hygiene making patients susceptible to periodontal diseases and caries. To prevent increased antimicrobial resistance A-PDT has shown itself a feasible option. The aim of this investigation was to assess the efficiency of A-PDT employing 1,9-Dimethyl-Methylene Blue zinc chloride double salt - DMMB as a photosensitizing agent combined with red LED irradiation (λ640 ± 5 ηm) against oral biofilm of patients undertaking orthodontic treatment. Twenty-one patients agreed to participate. Four biofilm collections were carried out on brackets and gingiva around inferior central incisors; first was carried out before any treatment (Control); second followed five minutes of pre-irradiation, the third was immediately after the first AmPDT, and the last after a second AmPDT. Then, a microbiological routine for microorganism growth was carried out and, after 24-h, CFU counting was performed. There was significant difference between all groups. No significant difference was seen between Control and Photosensitizer and AmpDT1 and AmPDT2 groups. Significant differences were observed between Control and AmPDT1 and AmPDT2 groups, Photosensitizer and AmPDT1 and AmPDT2 groups. It was concluded that double AmPDT using DMBB in nano concentration and red LED was capable to meaningfully decrease the number of CFUs in orthodontic patients.
Assuntos
Anti-Infecciosos , Fotoquimioterapia , Humanos , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fotoquimioterapia/métodos , ZincoRESUMO
This study aimed to evaluate, in vitro, the efficacy of photodynamic therapy - PDT using dimethyl methylene blue zinc chloride double salt (DMMB) and red LED light on planktonic cultures of Candida albicans. The tests were performed using the ATCC 90,028 strain grown at 37 °C for 24 h, according to a growth curve of C. albicans. The colonies were resuspended in sterile saline adjusted to a concentration of 2 × 108 cells / mL, with three experimental protocols being tested (Protocol 1, 2 and 3) with a fixed concentration of 750 ɳg/mL obtained through the IC50, and energy density 20 J/cm2. Protocol 1 was carried out using conventional PDT, Protocol 2 was applied double PDT in a single session, and Protocol 3 was applied double PDT in two sessions with a 24 h interval. The results showed logarithmic reductions of 3 (4.252575 ± 0.068526) and 4 logs (2.669533 ± 0.058592) of total fungal load in protocols 3 and 2 respectively in comparison to the Control (6.633547 ± 0.065384). Our results indicated that double application in a single session of PDT was the most effective approach for inhibiting the proliferation of Candida albicans (99.991% inhibition).
Assuntos
Candida albicans , Fotoquimioterapia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Luz , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêuticoRESUMO
This study aimed to perform a histological evaluation in skin lesions caused by Leishmania braziliensis after PACT treatment using Laser associated with 1.9. dimethyl methylene blue BALB/c mouse ear infection model was used. A total of 40 animals were assigned into two groups considering time intervals at 5 and 10 weeks and subdivided into four subgroups: Control, Photosensitizer, Laser and PACT. Two therapeutic interventions were performed after the 5th week of infection at 48 h intervals. 1.9 Dimethyl methylene blue was used as a photosensitizer at the concentration of 7 ng/mL, with a non-invasive topical administration method associated with Laser (λ = 660 nm, 40 mW, 12 J/cm2). Sample collection occurred 5 or 10 weeks after therapeutic interventions. The main histological findings were observed in the laser and PACT groups at the 10-week evaluation. The Laser group showed reduced lymphoplasmacytic inflammation and histiocytes (p = 0.0079). The PACT group showed reductions in lymphoplasmacytic inflammation at 5 and 10 weeks, discrete reduction of histiocytes and a higher percentage of tissue remodeling. PACT with non-invasive topical administration of the photosensitizer was able to reduce lymphoplasmacytic inflammation and increase tissue remodeling in leishmaniosis skin lesions. This protocol may be easily used in humans and clinical trial shall be carried out to confirm the animal's findings.
Assuntos
Leishmania braziliensis , Fotoquimioterapia , Animais , Inflamação/tratamento farmacológico , Lasers , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Camundongos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêuticoRESUMO
The repair of large bone defects is lengthy and complex. Both biomaterials and phototherapy have been used to improve bone repair. We aimed to describe histologically the repair of tibial fractures treated by wiring (W), irradiated or not, with laser (λ780 nm, 70 mW, CW, spot area of 0.5 cm2, 20.4 J/cm2 (4 × 5.1 J/cm2, Twin Flex Evolution®, MM Optics, Sao Carlos, SP, Brazil) per session, 300 s, 142.8 J/cm2 per treatment) or LED (λ850 ± 10 nm, 150 mW, spot area of 0.5 cm2, 20.4 J/cm2 per session, 64 s, 142.8 J/cm2 per treatment, Fisioled®, MM Optics, Sao Carlos, Sao Paulo, Brazil) and associated or not to the use of mineral trioxide aggregate (MTA, Angelus®, Londrina, PR, Brazil). Inflammation was discrete on groups W and W + LEDPT and absent on the others. Phototherapy protocols started immediately before suturing and repeated at every other day for 15 days. Collagen deposition intense on groups W + LEDPT, W + BIO-MTA + LaserPT and W + BIO-MTA + LEDPT and discrete or moderate on the other groups. Reabsorption was discrete on groups W and W + LEDPT and absent on the other groups. Neoformation varied greatly between groups. Most groups were partial and moderately filed with new-formed bone (W, W + LaserPT, W + LEDPT, W + BIO-MTA + LEDPT). On groups W + BIO-MTA and W + BIO-MTA + LaserPT bone, neoformation was intense and complete. Our results are indicative that the association of MTA and PBMT (λ = 780 nm) improves the repair of complete tibial fracture treated with wire osteosynthesis in a rodent model more efficiently than LED (λ = 850 ± 10 nm).
Assuntos
Compostos de Alumínio/farmacologia , Fios Ortopédicos , Compostos de Cálcio/farmacologia , Terapia com Luz de Baixa Intensidade , Óxidos/farmacologia , Silicatos/farmacologia , Fraturas da Tíbia/radioterapia , Fraturas da Tíbia/cirurgia , Compostos de Alumínio/uso terapêutico , Animais , Compostos de Cálcio/uso terapêutico , Combinação de Medicamentos , Óxidos/uso terapêutico , Roedores , Silicatos/uso terapêuticoRESUMO
Produced water (PW) is a by-product generated throughout oil exploration. Geological formation and geographical location of the reservoir influence its physical, chemical and biological characteristics. Xanthan gum (XG), an exopolysaccharide (EPS) produced by Xanthomonas campestris, has been widely used in enhanced oil recovery (EOR) technology because of its high viscosity, pseudoplastic behavior, stability in function of salinity, temperature and alkaline conditions. The production of XG may be affected by the composition of the PW, where the acetyl and pyruvyl radicals may be present in the mannoses. The aim of this study was to evaluate the composition of XG produced by X. campestris, particularly the amount of Xanthan, acetyl and pyruvyl groups, in culture mediums containing distilled (DW) or produced (PW) water in different concentrations, by means of dispersive Raman spectroscopy (1064 nm). The spectra of XG showed peaks referred to the main constituents of the Xanthan (glucose, mannose and glucuronic acid). Spectral features assigned to pyruvyl were seen in all samples mainly at ~1010 cm-1, with higher intensity when using DW and 25% PW. PCA loadings showed that the peaks assigned to pyruvyl are consistent to presence of sodium pyruvate (~1040/~1050 and ~ 1432 cm-1) and were higher in the samples obtained in 25% PW. ANOVA GLM applied to Raman peaks of interest (~1010 and ~ 1090 cm-1) and to PCA scores (Score 1 to Score 3) showed that both were influenced by the type of water used in the culture medium, where the XG were strongly reduced in the groups PW compared to DW while the pyruvyl content increased proportionally with the concentration of PW. The results suggest that the composition of the water used in the bacteria's culture medium influenced the composition of XG, including the amount of Xanthan and particularly the pyruvyl content, and therefore needs to be considered when using this approach of injecting XG in oil fields as pyruvyl content affects viscosity.
Assuntos
Campos de Petróleo e Gás/microbiologia , Polissacarídeos Bacterianos/química , Xanthomonas campestris/metabolismo , Glucose/química , Ácido Glucurônico/química , Manose/química , Campos de Petróleo e Gás/química , Óleos , Análise de Componente Principal , Ácido Pirúvico/química , Análise Espectral Raman , Viscosidade , Água/metabolismoRESUMO
Digital rectal examination (DRE) was the primary means to detect prostate diseases. The DRE has a high variability as it is based manly in the tactile sensitivity and expertise of the examiner. The prostate-specific antigen (PSA) test was initially developed for surveillance of prostate cancer and later it was also used as a diagnosis test. Raman spectroscopy is a powerful analytical technique that can measure the chemical composition of complex biological samples, such as body fluids. Biochemical changes caused by diseases can lead to significant changes in the Raman spectra. This study aimed to identify the differences in the Raman spectra of serum samples with normal and altered PSA values and correlate these differences by using multivariate techniques (principal component analysis - PCA and partial least squares regression - PLS). A total of 321 spectra were collected from 108 subjects. Two hundred and seventy were obtained from 91 non-altered PSA samples and 51 spectra from 17 samples with altered PSA. Each spectrum acquired was standardized to the area under the curve (1-norm). Discriminating and quantitative models employing PCA and PLS were developed. The PCA analyses showed 85.7% predictive power (87.41% sensitivity and 76.47% specificity). The PLS test showed a near-perfect sensitivity (98.51%) and an intermediate specificity (62.75%). The quantitative model through PLS regression showed a good correlation between PSA values and the spectral features (r = 0.605). This preliminary study suggests that Raman spectroscopy could be efficiently used for screening patients with altered PSA as well as for follow-up of the treatment of the prostate cancer by using initially the PLS to identify the possible presence of the prostate cancer and later on use de PCA to confirm the diagnosis.
Assuntos
Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Análise Espectral Raman/métodos , Análise Discriminante , Humanos , Análise dos Mínimos Quadrados , Masculino , Análise de Componente Principal , Antígeno Prostático Específico/metabolismo , Sensibilidade e EspecificidadeRESUMO
The Enterococcus faecalis is a microorganism that causes multiple forms of resistance to a wide range of drugs used clinically. aPDT is a technique in which a visible light activates photosensitizer (PS), resulting in generation of reactive oxygen species that kill bacteria unselectively via an oxidative burst. aPDT is an alternative to antibiotics with the advantage of not causing resistance. The search for an alternative treatment of infections caused by E. faecalis, without using antibiotics, is off great clinical importance. The aim of present investigation was to assess the efficacy of using 3.32 ηg/mL of 1,9-dimethylmethylene blue (DMMB) as photosensitizer associated with the use of either Laser (λ660 nm) or LED (λ632⯱â¯2â¯nm) using different energy densities (6, 12 and 18â¯J/cm2) to kill E. faecalis in vitro. Under different experimental conditions, 14 study groups, in triplicate, were used to compare the efficacy of the aPDT carried out with either the laser or LED lights using different energy densities associated to DMMB. The most probable number method (MPN) was used for quantitative analysis. Photodynamic antimicrobial effectiveness was directly proportional to the energy density used, reaching at 18â¯J/cm2, 99.999998% reduction of the counts of E. faecalis using both light sources. The results of this study showed that the use of 3.32 ηg/mL of DMMB associated with the use 18â¯J/cm2 of LED light (λ632⯱â¯2â¯nm) reduced >7-log counts of planktonic culture of E. faecalis.
Assuntos
Enterococcus faecalis/efeitos dos fármacos , Luz , Azul de Metileno/análogos & derivados , Fármacos Fotossensibilizantes/farmacologia , Animais , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/veterinária , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Azul de Metileno/química , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/uso terapêuticoRESUMO
Light biotechnology is a promising tool for enhancing recalcitrant compounds biodegradation. Xenobiotics can cause a significant impact on the quality of the results achieved by sewage treatment systems due to their recalcitrance and toxicity. The optimization of bioremediation and industrial processes, aiming to increase efficiency and income is of great value. The aim of this study was to accelerate and optimize the hydrolysis of Remazol Brilliant Blue R by photo stimulating a thermophilic bacterial consortium. Three experimental groups were studied: control group; LED Group and Laser Group. The control group was exposed to the same conditions as the irradiated groups, except exposure to light. The samples were irradiated in Petri dishes with either a Laser device (λ660 nm, CW, θâ¯=â¯0.04â¯cm2, 40â¯mW, 325â¯s, 13â¯J/cm2) or by a LED prototype (λ632⯱â¯2â¯nm, CW, θâ¯=â¯0.5â¯cm2, 145â¯mW, 44â¯s, 13â¯J/cm2). We found that, within 48-h, statistically significant differences were observed between the irradiated and the control groups in the production of RNA, proteins, as well as in the degradation of the RBBR. It is concluded that, both Laser and LED light irradiation caused increased cellular proliferation, protein production and metabolic activity, anticipating and increasing the catabolism of the RBBR. Being the economic viability a predominant aspect for industrial propose our results indicates that photo stimulation is a low-cost booster of bioprocesses.
Assuntos
Antraquinonas/química , Processos Fotoquímicos , Xenobióticos/metabolismo , Antraquinonas/metabolismo , Antraquinonas/efeitos da radiação , Biodegradação Ambiental , Custos e Análise de Custo , Hidrólise , Lasers , Luz , Consórcios Microbianos/efeitos da radiação , Xenobióticos/efeitos da radiaçãoRESUMO
Cancer is a pathology characterized by increased cell progression and/or reduced programmed cell death. Melanoma shows a rapid increase in cell progression and its resistance to chemotherapy is associated with uncontrolled apoptosis and to mechanisms that increase the flow of the drug out of the cell. The objective of this study was to evaluate the effects of photodynamic therapy (PDT) on the cell proliferation and cellular alterations in B16F10 murine melanoma. For that, four experimental groups were evaluated: the control group; laser group (Ê = 660 ηm, 40 mW, 2.4 J/cm2); photosensitizer group (solution containing methylene blue and toluidine blue 1:1-12.5 µg/mL); PDT group. The incubation time was 30 min. Fluorescence microscopy assays were performed without fixation with the DAPI, monodansylcadaverine (MDC), and dihydroethidium (DHE) probes. Cell proliferation was also determined at 24-h time. The tests were performed in triplicate and the statistical test used was ANOVA with Tukey post-test. The results demonstrate that the plasma membrane of the cells of all the experimental groups remained intact, ROS production and autophagy significantly increased (p < 0.0005 and p < 0.0071, respectively) only in the PDT group. The cell proliferation essay showed a reduction of 74.2% on the PDT group in relation to the control group. The present study demonstrated that oxidative stress promoted by photodynamic therapy may induce autophagy and consequently reduce cell proliferation in B16F10 melanoma.
Assuntos
Autofagia , Melanoma Experimental/patologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Fluorescência , Humanos , Lasers , Melanoma Experimental/tratamento farmacológico , Azul de Metileno/farmacologia , Camundongos , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêuticoRESUMO
The aim of the present study was to assess, by means of Raman spectroscopy, the repair of complete surgical tibial fractures fixed with wire osteosynthesis (WO) treated or not with infrared laser (λ780 nm) or infrared light emitting diode (LED) (λ850 ± 10 nm) lights, 142.8 J/cm2 per treatment, associated or not to the use of mineral trioxide aggregate (MTA) cement. Surgical tibial fractures were created on 18 rabbits, and all fractures were fixed with WO and some groups were grafted with MTA. Irradiated groups received lights at every other day during 15 days, and all animals were sacrificed after 30 days, being the tibia removed. The results showed that only irradiation with either laser or LED influenced the peaks of phosphate hydroxyapatite (~ 960 cm-1). Collagen (~ 1450 cm-1) and carbonated hydroxyapatite (~ 1070 cm-1) peaks were influenced by both the use of MTA and the irradiation with either laser or LED. It is concluded that the use of either laser or LED phototherapy associated to MTA cement was efficacious on improving the repair of complete tibial fractures treated with wire osteosynthesis by increasing the synthesis of collagen matrix and creating a scaffold of calcium carbonate (carbonated hydroxyapatite-like) and the subsequent deposition of phosphate hydroxyapatite.
Assuntos
Fios Ortopédicos , Fixação Interna de Fraturas/métodos , Consolidação da Fratura/efeitos da radiação , Terapia com Luz de Baixa Intensidade/métodos , Análise Espectral Raman , Fraturas da Tíbia/radioterapia , Fraturas da Tíbia/cirurgia , Análise de Variância , Animais , Colágeno , Durapatita/química , Masculino , Coelhos , Tíbia/efeitos da radiação , Tíbia/cirurgiaRESUMO
The aim of this study was to evaluate the lethal potential of macrophages infected with Staphylococcus aureus after PACT (Photochemical Antimicrobial Chemotherapy) using phenothiazine derivatives (a solution containing 1:1 methylene blue and O toluidine blue) and laser (660â¯nm, 40â¯mW, 60â¯s, 12â¯J/cm2) or LED (632⯱â¯2â¯nm, 145â¯mW, 40â¯s, 12â¯J/cm2). Six experimental groups were evaluated: Control Group (untreated); Photosensitizer group (phenothiazines - 12.5⯵g/mL); Laser Group; LED Group; Laser PACT Group; and LED PACT Group. The pre-irradiation time used in this study was 5â¯min. Macrophages and bacteria were cultured in specific culture media and/or allowed interaction between the cell types. Subsequently, tests were carried out to evaluate microbial proliferation, ROS production by macrophages and survival capacity of S. aureus after phagocytosis. Fluorescence microscopy assays were performed with the H2DCFDA probe, after PACT, at the initial time (0â¯h), 4-h and 12-h. The tests were performed in triplicate and the statistical test used was ANOVA with Tukey post-test. After PACT, a statistically significant difference (pâ¯>â¯0.0001) was observed between the microbial growth of the control group and the PACTs groups. Laser PACT and LED PACT groups presented, respectively, reductions of 84.2% and 81.5% when compared to control and 53.3% and 46% when compared to the photosensitizer group. It is concluded that the therapeutic protocols presented in this study increased the phagocytic capacity, the response rate of the phagocytes and the consequent reduction of the numbers of S. aureus for both PACT protocols, however the increase in ROS production was only observed in the group irradiated with Laser light.
Assuntos
Macrófagos/efeitos dos fármacos , Fenotiazinas/farmacologia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Luz , Macrófagos/microbiologia , Azul de Metileno/farmacologia , Microscopia de Fluorescência , Cloreto de Tolônio/farmacologiaRESUMO
Cellulose has a highly diversified architecture and its enzymatic complexes are studied for achieving an efficient conversion and a high level of efficiency in the deconstruction of cellulolytic biomass into sugars. The aim of this investigation was to evaluate the effect of Laser or LED light in the cellulolytic activity (CMCase) and on the proliferation of the thermophilic microbial consortium used on the degradation process of a lignocellulosic biomass of green coconut shell. The irradiation protocol consisted of six Laser irradiations (λ660â¯Î·m, 40â¯mW, 270â¯s, 13â¯J/cm2) or LED (λ632⯱â¯2â¯Î·m, 145â¯mW, 44â¯s, 13â¯J/cm2) with 12- h time intervals in nutrient deprivation conditions. After irradiation, the consortium was inoculated into a lignocellulosic biomass (coconut fibers). Non- irradiated consortium was also inoculated and acted as control. Cell proliferation and endoglucanase activity were quantified during the experimental time. Experiments were carried out in triplicate. The results showed an increase of 250 % of thermo-cellulolytic microorganisms for the LED group and 200% for the Laser group when compared to the control. The enzymatic index (red Congo method), showed a statistically significant difference in the process of degradation of the lignocellulosic biomass between the Laser and LED groups compared to the control group [pâ¯<â¯0.0029; pâ¯<â¯0.029, respectively] 48-hs after the inoculation of the microorganisms. At the end of 72-h, this significant difference was maintained for both irradiated groups (pâ¯<â¯0.0212). Based upon the protocol used on the present study, it is possible to concluded that LED light enhanced cell proliferation of the thermophilic microbial consortium while the Laser light increase the enzymatic index of the lignocellulosic biomass of green coconut shell.
Assuntos
Lasers , Luz , Consórcios Microbianos/fisiologia , Proteínas de Bactérias/metabolismo , Biomassa , Celulase/metabolismo , Celulose/química , Celulose/metabolismo , Cocos/metabolismo , Bactérias Gram-Positivas/enzimologia , Bactérias Gram-Positivas/crescimento & desenvolvimento , Hidrólise/efeitos da radiação , Microscopia de FluorescênciaRESUMO
The objective of this study was to evaluate, in vitro, the bactericidal effect of AmPDT on Staphylococcus aureus (ATCC 25923) using different concentrations (100, 50, 25, 12.5 and 6.25µg/mL) of phenothiazine compound combined with LED light (λ632±2nm) using varied energy densities (12, 9.6, 7.2, 4.8 and 2.4J/cm2). The experiments were carried out in triplicate and the samples were divided into groups: Control, Irradiated (treated only with light at different energy densities), Photosensitizer (treated only in the presence of the dye), AmPDT (treatment with light associated with dye). Counts of the colony forming units and the data obtained were statistically analyzed (ANOVA, Tukey's test, p<0.05). The results showed no difference between irradiated and Control groups. However, using the photosensitizer alone caused significant increased cytotoxicity and consequent reduction on the CFU counts (12.5µg/mL (p<0.001), 25µg/mL, 50µg/mL and 100µg/mL (p<0.0001). When AmPDT was used significant inhibition above 70% were detected for all concentrations of the photosensitize (p<0.0001) except for 6.25µg/mL. The results indicate a dose-response dependent when the photosensitizer is used alone but not for the sole use of the light is used. It is concluded that, a single application of AmPDT, using energy density of 12J/cm2 associated either to 12.5 (81.52%) or 25µg/mL (91.57%) resulted in higher in vitro inhibition of S. aureus.
Assuntos
Anti-Infecciosos/farmacologia , Luz , Fenotiazinas/química , Fármacos Fotossensibilizantes/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos/química , Corantes/química , Corantes/farmacologia , Testes de Sensibilidade Microbiana , Fenotiazinas/farmacologia , Fármacos Fotossensibilizantes/química , Staphylococcus aureus/efeitos da radiação , TermodinâmicaRESUMO
The aim of this study was to evaluate, in vitro, the bactericidal effect of antimicrobial photodynamic therapy (AmPDT) using phenothiazinium dyes (Toluidine Blue O and methylene blue, 1:1) using different concentrations (100, 50, 25, 12.5, and 6.25 µg/mL) associated to red laser with different energy densities (2.4, 4.8, 7.2, 9.6, and 12 J/cm2) on a strain of Staphylococcus aureus (ATCC 23529). On this study, tests were performed in triplicate and the samples were distributed into 36 test groups: Control and bacterial suspensions were irradiated with the different energy densities, respectively, in the absence of photosensitizer, bacterial suspensions were irradiated with the laser in the different concentrations of the photosensitizer, and finally bacterial suspensions only in the presence of phenothiazinium dye. The pre-irradiation time was 5 min. Therefore, we analyzed the potential of the AmPDT by counting colony-forming units. The logarithm of CFU/mL (log10 CFU/mL) was calculated and the data was analyzed statistically (ANOVA, Tukey's test, p < 0.05). The results showed that the association 50 and 100 µg/mL with 12 J/cm2 showed the highest percentage of inhibition (100 %). Based upon the present results, it may be concluded that the AmPDT was able to enhance the antimicrobial effect of phenothiazines and both concentration of the compound and energy density are important factors for greater effectiveness of therapy.
Assuntos
Anti-Infecciosos/farmacologia , Lasers , Fenotiazinas/farmacologia , Fotoquimioterapia , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/crescimento & desenvolvimentoRESUMO
Temporomandibular disorders (TMDs) are mostly inflammatory conditions widespread in the population. Previous studies have shown positive effects of either laser or light-emitting diode (LED) phototherapies on treating TMDs, but their action and mechanism in the inflammatory infiltrate of the temporomandibular joint are still poorly understood. The aim of this study was to assess, through histological analysis, the effectiveness of using laser light (λ 780 nm, 70 mW, continous wave (CW), 10 J) and LED (λ 850 ± 10 nm, 100 mW, CW, 10 J) on the inflammation of the temporomandibular joint of rats induced by carrageenan. Forty-five animals were divided into three groups with five animals each according to the experimental times of 2, 3, and 7 days: inflammation, inflammation+laser phototherapy, and inflammation+LED phototherapy. The first irradiation was performed 24 h after induction with an interval of 48 h between sessions. After animal death, specimens were processed and stained with hematoxylin-eosin (HE) and picrosirius. Then, the samples were examined histologically. Data were statistically analyzed. The inflammation group showed mild to moderate chronic inflammatory infiltrate between bone trabecules of the condyle. Over the time course of the study in the laser group, the region of the condyle presented mild chronic inflammation and intense vascularization. In the LED group, the condyle showed aspects of normality and absence of inflammation in some specimens. In all the time points, the laser-irradiated groups showed greater amount of collagen deposition in the condyle (p = 0.04) and in the disc (p = 0.03) when compared to the inflammation and LED groups, respectively. Laser- and LED-treated groups demonstrate a smaller number of layers of the synovial membrane when compared to the non-irradiated groups. It was concluded that, in general, laser and LED phototherapies resulted in a reduction of inflammatory infiltrate in the temporomandibular joint of rat.
Assuntos
Inflamação/patologia , Lasers , Terapia com Luz de Baixa Intensidade/métodos , Articulação Temporomandibular/patologia , Articulação Temporomandibular/efeitos da radiação , Animais , Carragenina , Colágeno/metabolismo , Masculino , Neovascularização Fisiológica , Ratos WistarRESUMO
Iron deficiency impairs the formation of hemoglobin, red blood cells, as well the transport of oxygen. The wound healing process involves numerous functions, many of which are dependent on the presence of oxygen. Laser has been shown to improve angiogenesis, increases blood supply, cell proliferation and function. We aimed to study the effect of λ660 nm laser and λ700 nm light-emitting diode (LED) on fibroblastic proliferation on cutaneous wounds on iron-deficient rodents. Induction of iron anemia was carried out by feeding 105 newborn rats with a special iron-free diet. A 1 × 1 cm wound was created on the dorsum of each animal that were randomly distributed into seven groups: I, control anemic; II, anemic no treatment; III, anemic+L; IV, anemic+LED; V, healthy no treatment; VI, healthy+laser; VII, healthy+LED (n=15 each). Phototherapy was carried out using either a diode laser (λ660 nm, 40 mW, 10 J/cm(2)) or a prototype LED device (λ700 ± 20 nm, 15 mW, 10 J/cm(2)). Treatment started immediately after surgery and was repeated at 48-h interval during 7, 14, and 21 days. After animal death, specimens were taken, routinely processed, cut, stained with hematoxylin-eosin, and underwent histological analysis and fibroblast counting. Significant difference between healthy and anemic subjects on regards the number of fibroblast between treatments was seen (p<0.008, p<0.001). On healthy animals, significant higher count was seen when laser was used (p<0.008). Anemic subjects irradiated with LED showed significantly higher count (p<0.001). It is concluded that the use of LED light caused a significant positive biomodulation of fibroblastic proliferation on anemic animals and laser was more effective on increasing proliferation on non-anemics.
Assuntos
Terapia com Luz de Baixa Intensidade , Fototerapia , Pele/lesões , Pele/efeitos da radiação , Cicatrização/efeitos da radiação , Anemia Ferropriva/patologia , Anemia Ferropriva/radioterapia , Animais , Animais Recém-Nascidos , Proliferação de Células/efeitos da radiação , Modelos Animais de Doenças , Fibroblastos/patologia , Fibroblastos/efeitos da radiação , Luz , Masculino , Ratos , Ratos Wistar , Pele/patologiaRESUMO
The aim of the present study was to assess, by Raman spectroscopy, the repair of surgical fractures fixed with internal rigid fixation (IRF) treated or not with IR laser (λ780 nm, 50 mW, 4 × 4 J/cm(2) = 16 J/cm(2), Ï = 0.5 cm(2), CW) associated or not to the use of hydroxyapatite and guided bone regeneration (GBR). Surgical tibial fractures were created under general anesthesia on 15 rabbits that were divided into five groups, maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet and had water ad libitum. The fractures in groups II, III, IV and V were fixed with miniplates. Animals in groups III and V were grafted with hydroxyapatite and GBR technique used. Animals in groups IV and V were irradiated at every other day during 2 weeks (4 × 4 J/cm(2), 16 J/cm(2) = 112 J/cm(2)). Observation time was that of 30 days. After animal death, specimens were taken and kept in liquid nitrogen and used for Raman spectroscopy. Raman spectroscopy showed significant differences between groups (p < 0.001). Basal readings showed mean value of 1,234 ± 220.1. Group internal rigid fixation + biomaterial + laser showed higher readings (3,521 ± 2,670) and group internal rigid fixation + biomaterial the lowest (212.2 ± 119.8). In conclusion, the results of the present investigation are important clinically as spectral analysis of bone component evidenced increased levels of CHA on fractured sites by using the association of laser light to a ceramic graft.
Assuntos
Regeneração Óssea/efeitos da radiação , Substitutos Ósseos , Fixação Interna de Fraturas/métodos , Regeneração Tecidual Guiada/métodos , Terapia com Luz de Baixa Intensidade/métodos , Animais , Placas Ósseas , Substitutos Ósseos/uso terapêutico , Cerâmica , Durapatita , Masculino , Coelhos , Análise Espectral Raman , Fraturas da Tíbia/radioterapia , Fraturas da Tíbia/terapiaRESUMO
OBJECTIVE: We aimed to assess histologic changes after the use of laser phototherapy (LPT) during induced tooth movement with 40 g/F on young adult male rats. BACKGROUND DATA: Hyalinization is a sterile necrosis at the pressure zone of the periodontal ligament observed during the initial stages of the orthodontic movement, and extensive hyaline areas might cause an important delay in the tooth movement. The use of LPT is considered an enhancement factor for bone repair, as it stimulates microcirculation as well as the cellular metabolism. MATERIALS AND METHODS: Thirty animals were divided into two groups (n=15), named according to the time of animal death (7, 13, and 19 days). Half of the animals in each group were subjected to irradiation with infrared (IR) laser (λ790 nm, round shaped beam, 40 mW, continuous wave (CW), diameter=2 mm (0.0314 cm(2)), 1.273 W/cm(2), time=2×112 sec+1×275 sec (total time 499 sec), 2×142.6/4.48 J+1×350/11 J, 635.2 J/cm(2)/20 J/ session), during orthodontic movement, the other half were used as nonirradiated controls. After animal death, specimens were sectioned, processed, and stained with hematoxylin and eosin (HE) and Sirius Red, and were used for semi-quantitative histologic analysis by light microscopy. Data were statistically analyzed. RESULTS: We demonstrated that LPT positively affected an important aspect of dental movement; the hyalinization. In the present study, we found a significant reduced expression of hyalinization after 19 days. On irradiated subjects, hyalinization was increased at day 7 with significant reduction at day 13. CONCLUSIONS: It is possible to conclude that the use of laser light caused histologic alterations during the orthodontic movement characterized by increased formation of areas of hyalinization at early stages, and late reduction when compared to nonirradiated animals.
Assuntos
Processo Alveolar/efeitos da radiação , Hialina/efeitos da radiação , Terapia com Luz de Baixa Intensidade/métodos , Ligamento Periodontal/efeitos da radiação , Técnicas de Movimentação Dentária/métodos , Processo Alveolar/patologia , Animais , Modelos Animais de Doenças , Hialina/metabolismo , Imuno-Histoquímica , Masculino , Ligamento Periodontal/patologia , Fotomicrografia , Distribuição Aleatória , Ratos , Ratos Wistar , Valores de Referência , Resultado do TratamentoRESUMO
This work carried out a histological analysis on bone defects grafted (MTA) treated or not with LED, BMPs, and membrane (GBR). Benefits of their isolated or combined usage on bone repair were reported, but not their association. Ninety rats were divided into ten groups and each subdivided into three. Defects on G II and I were filled with the blood clot. G II was further LED irradiated. G III and IV were filled with MTA; G IV was further LED irradiated. In G V and VI, the defects were filled with MTA and covered with a membrane (GBR). G VI was further LED irradiated. In G VII and VIII, BMPs were added to the MTA and group VIII was further LED irradiated. In G IX and X, the MTA + BMP graft was covered with a membrane (GBR). G X was further LED irradiated. LED was applied over the defect at 48-h intervals and repeated for 15 days. Specimens were processed, cut, and stained with H&E and Sirius red and underwent histological analysis. The use of LED light alone dramatically reduced inflammation. However, its use on MTA associated with BMP and/or GBR increased the severity of the inflammatory reaction. Regarding bone reabsorption, the poorest result was seen when the LED light was associated with the MTA + BMP graft. In the groups Clot and MTA + GBR, no bone reabsorption was detectable. Increased collagen deposition was observed when the LED light was associated with the use of the MTA associated with BMP and/or GBR. Increased new bone formation was observed when the LED light was used alone or associated with the use of MTA + GBR, MTA + BMP, on association of MTA + BMP + GBR and when BMP was added to the MTA. Our results indicate that the use of LED light alone or in association with MTA, MTA + BMP, MTA + GBR, and MTA + BMP + GBR caused less inflammation, and an increase of both collagen deposition and bone deposition as seen on both histological and morphometric analysis.