Aplicação do plasma de baixa temperatura sob pressão atmosférica como adjuvante ao tratamento da mucosite oral / Application of low temperature atmospheric pressure plasma as an adjuvant in treatment oral mucositis

A mucosite oral é um quadro clínico que acomete frequentemente pacientes sob terapia antineoplásica na região de cabeça e pescoço e caracteriza-se por ulcerações na mucosa que geram intensa dor local, odinofagia, aumento do risco de infecções, do uso de antibióticos e do tempo de hospitalização. A correlação entre mucosite oral, infecção fúngica e o potencial de disseminação fúngica sistêmica foi recentemente descrita. Apesar do impacto desse quadro clínico sobre a qualidade e tempo de vida dos pacientes oncológicos, não há consenso sobre a profilaxia e o protocolo terapêutico. O plasma de baixa temperatura sobre pressão atmosférica (LTAPP) apresenta efeito antimicrobiano, anti-inflamatório e reparador tecidual, o que sugere que possa ser promissor no tratamento da mucosite oral. Os objetivos gerais deste projeto foram divididos em dois subprojetos: 1) Definir os melhores parâmetros in vitro com efeito antifúngico e não tóxico e avaliar o LTAPP no tratamento de lesão de mucosite oral em modelo murino de mucosite por quimioterapia e 2) avaliar se o tratamento com LTAPP pode prevenir a disseminação fúngica sistêmica em ratos a partir de infecção experimental de lesões de mucosite oral por Candida albicans. Para tal, foram incluídos no estudo 100 ratos (Rattus norvegicus) com 90 a 100 dias de idade. No subprojeto 1, a lesão de mucosite oral foi induzida por administração de 5 fluorouracila (5-FU), enquanto no subprojeto 2, utilizou-se 5-FU associada à cisplatina ambas associadas à aplicação tópica de ácido acético 50%. Para o subprojeto 1, os animais foram randomicamente divididos em 2 grupos experimentais (n=30): a) Grupo mucosite; b) Grupo mucosite tratado com LTAPP, avaliados após 1, 5 e 12 dias do tratamento. Durante o período experimental, as lesões foram fotografadas e a gravidade da mucosite classificada por meio da atribuição de escores. Após a eutanásia e o processamento, os cortes histológicos corados por hematoxilina-eosina (HE) foram analisados microscopicamente. Para o subprojeto 2, o estudo de disseminação sistêmica fúngica nos grupos de mucosite infectada com C. albicans tratado ou não com LTAPP foi conduzido pelo isolamento fúngico a partir de amostras de sangue total e macerado dos órgãos. Para tanto foram estudados 2 grupos de ratos (n=20): c) Grupo mucosite infectado com C. albicans e d) Grupo mucosite infectado com C. albicans tratada com LTAPP, avaliados após 24 e 72 h do tratamento. Para ambos os projetos, o melhor parâmetro in vitro foi selecionado, isto é aquele com maior atividade antifúngica e baixa toxicidade. Dessa forma, as lesões foram expostas ao LTAPP de hélio por 5 min na distância de 1,5 cm na potência de 1 W. Os resultados in vitro mostraram que o LTAPP teve efeito antifúngico e baixa toxicidade para células de mamíferos. Os resultados in vivo mostraram que 5-FU afetou a saúde geral dos animais, evidenciada pela perda de peso corporal. Em ambos os grupos, houve reparo tecidual após 12 dias do tratamento, com resolução quase completa da lesão, o que foi corroborado pelos achados microscópicos. O grupo LTAPP exibiu uma tendência maior de redução da lesão, após 12 dias de tratamento. Além disso, o LTAPP apresentou efeito inibitório sobre C. albicans após 5 minutos, de exposição, com redução da recuperação fúngica da língua após 24 h (p<0.05). A disseminação fúngica sistêmica foi reduzida significativamente após 24 e 72 h do tratamento. Com base nos resultados obtidos, conclui-se que o LTAPP é uma ferramenta promissora para futura aplicação clínica em pacientes com mucosite oral. (AU)

Oral mucositis is a clinical condition that frequently affects patients undergoing antineoplastic therapy in the head and neck region and is characterized by mucosal ulcerations that generate intense local pain, odynophagia, increased risks of infections, use of antibiotics and the length of hospital stay. The correlation among oral mucositis, fungal infection and the potential for systemic fungal dissemination has recently been described. Despite the impact of this clinical condition on the quality and life expectancy of cancer patients, there is no consensus on prophylaxis and the therapeutic protocols. Low temperature atmospheric pressure plasma (LTAPP) has antimicrobial, anti-inflammatory and tissue repairing effects, which suggests that it can be promising in the treatment of oral mucositis. The general objectives of this project were divided into two subprojects: 1) Define the best antifungal and non-toxic in vitro parameters and to evaluate the application of LTAPP in the treatment of oral mucositis in murine model for chemotherapy, and 2) to evaluate whether treatment with LTAPP can prevent systemic fungal dissemination in rats from experimental infection of oral mucositis lesions by Candida albicans. A total of 100 rats (Rattus norvegicus) aged 90 to 100 days were included in the study. In subproject 1, oral mucositis lesion was induced by administration of only 5- fluorouracil (5-FU), while in subproject 2, administration and systemic administration of 5-FU associated with cisplatin, both associated with topical application of 50% acetic acid. For subproject 1, the animals were randomly divided into 2 experimental groups (n=30):a) Mucositis group and b) Mucositis group treated with LTAPP evaluated after 1, 5 and 12 days of treatment. During the experimental period, the lesions were photographed, and the severity of mucositis was classified into scores. After euthanasia and processing, the histological cuts stained by hematoxylin-eosin (HE) were analyzed. For subproject 2, the study of fungal systemic dissemination in groups of mucositis infected with C. albicans treated or not with LTAPP was conducted by fungal isolation from whole blood and macerated organs. Therefore, 2 groups of rats (n=20) were studied: c) Mucositis group infected with C. albicans and d) Mucositis group infected with C. albicans treated with LTAPP, evaluated after 24 and 72 h of treatment. For both subprojects, the best in vitro parameter was selected, that is, the one with the greatest antifungal effect and low toxicity. Thus, the lesions were exposed to helium LTAPP for 5 min at a distance of 1.5 cm at power of 1 W. In vitro results showed that LTAPP has an antifungal effect and low toxicity. In vivo results showed that 5-FU affected the general health of animals evidenced by body weight loss. In both groups, there was tissue repair after 12 days of treatment, with almost complete resolution of the lesion, which was corroborated by the microscopic findings. LTAPP group showed a greater trend of reduction of lesion, after 12 days of the treatment. Furthermore, LTAPP showed inhibitory effect on C. albicans after 5 min of exposition, with reduction in fungal recovery from the tongue after 24 h (p<0.05). Reduction in fungal dissemination was observed after 24 and 72 h of LTAPP treatment (p<0.05). Based on the obtained results, it was concluded that LTAPP is a promising tool for future clinical application in patients with oral mucositis.(AU)

Efeito da aplicação de plasma não-térmico atmosférico no reparo de cerâmicas CAD/CAM de matriz resinosa com resina composta / Effect of non-thermal atmospheric plasma application on the resin composite repair of resin matrix CAD/CAM ceramics

O objetivo deste trabalho foi avaliar o efeito do plasma atmosférico não-térmico (PANT), sozinho ou associado ao jateamento ou adesivo, e do tempo de armazenamento em água na resistência de união por cisalhamento (RUC) do reparo de cerâmicas CAD/CAM de matriz resinosa (CMR) com resina composta. Amostras de 14x7x1mm de três CMRs, Enamic (VITA Zahnfabrik), Cerasmart (GC Corp.) e Lava Ultimate (3M Oral Care), foram obtidas e submetidas ao envelhecimento artificial (EQ-UV, Equilam) por 300 horas. Os seguintes tratamentos de superfície foram realizados: (1- Controle) jateamento + silano + adesivo; (2) PANT; (3) PANT + adesivo; (4) jateamento + PANT. Cilindros de resina composta (Spectra Smart, Dentsply Sirona, 1,5 mm diâmetro e altura) foram aderidos às superfícies tratadas e a RUC foi avaliada em uma máquina de ensaio universal (EZ Test, Shimadzu) após 24 horas ou 1 ano de imersão em água, a 37oC (n=10). No geral, o tratamento controle obteve os melhores resultados de RUC, comparado aos grupos tratados com PANT. Houve redução da RUC após 1 ano de imersão em água para a maioria dos grupos, entre eles para o controle do Enamic e Lava Ultimate, enquanto Cerasmart não mostrou redução. O tratamento com PANT, sozinho ou associado a outro tratamento, não foi capaz de aumentar a RUC do reparo das CMRs com resina composta. O tratamento controle parece ser o melhor método de reparo das CMRs, principalmente considerando-se a longevidade do tratamento.

The objective of this study was to evaluate the effect of nonthermal atmospheric plasma (NTAP), alone or combined with sandblasting or adhesive, and water-storage time on the shear bond strength (SBS) of resin composite repair of resin matrix ceramics (RMC). Samples (14x7x1mm) of three RMCs, Enamic (VITA Zahnfabrik), Cerasmart (GC Corp.), and Lava Ultimate (3M Oral Care), were prepared and submitted to artificial aging (EQ-UV, Equilam) for 300 h. The following surface treatments were performed: (1- Control) sandblasting + silane + adhesive; (2) NTAP; (3) NTAP + adhesive; (4) sandblasting + NTAP. Resin composite cylinders (Spectra Smart, Dentsply Sirona, 1,5 mm diameter and height) were bonded to the treated surfaces and the SBS was evaluated in a universal testing machine (EZ Test, Shimadzu) after 24 h or 1 year of water storage, at 37oC (n=10). In general, the control treatment obtained the best SBS results, compared to groups treated with NTAP. There was a decrease in SBS after 1 year of water immersion for most groups, including the control treatment for Enamic and Lava Ultimate, while Cerasmart presented no reduction. The treatment with NTAP alone or combined with another treatment, was not capable of increasing the SBS of resin composite repair to RMCs. Control treatment seems to be the best method for repairing CMRs, mainly considering the treatment longevity.

The effect of plasma on shear bond strength between resin cement and colored zirconia

PURPOSE: To investigate the effect of non-thermal atmospheric pressure plasma (NTAPP) treatment on shear bond strength (SBS) between resin cement and colored zirconia made with metal chlorides. MATERIALS AND METHODS: 60 zirconia specimens were divided into 3 groups using coloring liquid. Each group was divided again into 2 sub-groups using plasma treatment; the experimental group was treated with plasma, and the control group was untreated. The sub-groups were: N (non-colored), C (0.1 wt% aqueous chromium chloride solution), M (0.1 wt% aqueous molybdenum chloride solution), NP (non-colored with plasma), CP (0.1 wt% aqueous chromium chloride solution with plasma), and MP (0.1 wt% aqueous molybdenum chloride solution with plasma). Composite resin cylinders were bonded to zirconia specimens with MDP-based resin cement, and SBS was measured using a universal testing machine. All data was analyzed statistically using a 2-way ANOVA test and a Tukey test. RESULTS: SBS significantly increased when specimens were treated with NTAPP regardless of coloring (P<.001). Colored zirconia containing molybdenum showed the highest value of SBS, regardless of NTAPP. The molybdenum group showed the highest SBS, whereas the chromium group showed the lowest. CONCLUSION: NTAPP may increase the SBS of colored zirconia and resin cement. The NTAPP effect on SBS is not influenced by the presence of zirconia coloring.

Comparative Effects of Non-Thermal Atmospheric Pressure Plasma on Migration and Invasion in Oral Squamous Cell Cancer, by Gas Type

PURPOSE: The fourth state of matter, plasma is known as an ionized gas with electrons, radicals and ions. The use of non-thermal plasma (NTP) in cancer research became possible because of the progresses in plasma medicine. Previous studies on the potential NTP-mediated cancer therapy have mainly concentrated on cancer cell apoptosis. In the present study, we compared the inhibitory effect of NTP on cell migration and invasion in the oral squamous cancer cell lines. MATERIALS AND METHODS: We used oral squamous cancer cell lines (SCC1483, MSKQLL1) and different gases (N₂, He, and Ar). To investigate the mechanism of plasma treatment, using different gases (N₂, He, and Ar) which induces anti-migration and anti-invasion properties, we performed wound healing assay, invasion assay and gelatin zymography. RESULTS: The results showed that NTP inhibits cancer cell migration and invasion of oral squamous cancer cell. In addition, focal adhesion kinase expression and matrix metalloproteinase-2/9 activity were also inhibited. CONCLUSION: The suppression of cancer cell invasion by NTP varied depending on the type of gas. Comparison of the three gases revealed that N₂ NTP inhibited cell migration and invasion most potently via decreased expression of focal adhesion kinase and matrix metalloproteinase activity.

Effect of atmospheric plasma versus conventional surface treatments on the adhesion capability between self-adhesive resin cement and titanium surface

PURPOSE: The aim of this study was to evaluate the effects of atmospheric plasma (APL) versus conventional surface treatments on the adhesion of self-adhesive resin cement to Ti-6Al-4V alloy. MATERIALS AND METHODS: Sixty plates of machined titanium (Ti) discs were divided into five groups (n=12): 1) Untreated (CNT); 2) Sandblasted (SAB); 3) Tribochemically treated (ROC); 4) Tungsten CarbideBur (TCB); 5) APL treated (APL). SEM analysis and surface roughness (Ra) measurements were performed. Self-adhesive resin cement was bonded to the Ti surfaces and shear bond strength (SBS) tests, Ra and failure mode examinations were carried out. Data were analyzed by one-way analysis of variance and chi-squared test. RESULTS: The lowest SBS value was obtained with CNT and was significantly different from all other groups except for APL. The ROC showed the highest SBS and Ra values of all the groups. CONCLUSION: It was concluded that the effect of APL on SBS and Ra was not sufficient and it may not be a potential for promoting adhesion to titanium.

Non-Thermal Atmospheric-Pressure Plasma Possible Application in Wound Healing

Non-thermal atmospheric-pressure plasma, also named cold plasma, is defined as a partly ionized gas. Therefore, it cannot be equated with plasma from blood; it is not biological in nature. Non-thermal atmospheric-pressure plasma is a new innovative approach in medicine not only for the treatment of wounds, but with a wide-range of other applications, as e.g. topical treatment of other skin diseases with microbial involvement or treatment of cancer diseases. This review emphasizes plasma effects on wound healing. Non-thermal atmospheric-pressure plasma can support wound healing by its antiseptic effects, by stimulation of proliferation and migration of wound relating skin cells, by activation or inhibition of integrin receptors on the cell surface or by its pro-angiogenic effect. We summarize the effects of plasma on eukaryotic cells, especially on keratinocytes in terms of viability, proliferation, DNA, adhesion molecules and angiogenesis together with the role of reactive oxygen species and other components of plasma. The outcome of first clinical trials regarding wound healing is pointed out.

Evaluation of the safety of non-thermal atmospheric-pressure plasma in hairless mouse tissues / 대한구강보건학회지

OBJECTIVES: The aim of the present study was to evaluate the stability of non-thermal atmospheric-pressure plasma on Candida albicans in hairless mouse-2 (HRM-2) tissues. METHODS: HRM-2 mice were subjected to non-thermal atmospheric-pressure plasma jet treatment using an optical fiber probe and monitored using a thermometer. The skin of HRM-2 mice was treated with plasma jet for 0, 60, 180, and 300 s per day for 5 days. After plasma treatment, morphological changes in Candida albicans on the skin of these mice were examined using a scanning electron microscope. Biopsy of the plasma-treated skin was performed and the tissues were histologically analyzed using hematoxylin and eosin (H&E) and Masson's trichrome stains. RESULTS: The scanning electron microscopic images revealed the morphological changes in the membrane structure of the plasma-treated Candida albicans. Histological analysis showed that non-thermal plasma treatment did not cause epidermal damage or tissue inflammation and did not significantly modify the collagen layers of the mouse skin. CONCLUSIONS: The results of this study suggest that non-thermal atmospheric-pressure plasma might be safe and effective for clinical applications in the field of dentistry.

Sterilization effect of atmospheric pressure non-thermal air plasma on dental instruments

PURPOSE: Autoclaves and UV sterilizers have been commonly used to prevent cross-infections between dental patients and dental instruments or materials contaminated by saliva and blood. To develop a dental sterilizer which can sterilize most materials, such as metals, rubbers, and plastics, the sterilization effect of an atmospheric pressure non-thermal air plasma device was evaluated. MATERIALS AND METHODS: After inoculating E. coli and B. subtilis the diamond burs and polyvinyl siloxane materials were sterilized by exposing them to the plasma for different lengths of time (30, 60, 90, 120, 180 and, 240 seconds). The diamond burs and polyvinyl siloxane materials were immersed in PBS solutions, cultured on agar plates and quantified by counting the colony forming units. The data were analyzed using one-way ANOVA and significance was assessed by the LSD post hoc test (alpha=0.05). RESULTS: The device was effective in killing E. coli contained in the plasma device compared with the UV sterilizer. The atmospheric pressure non-thermal air plasma device contributed greatly to the sterilization of diamond burs and polyvinyl siloxane materials inoculated with E. coli and B. subtilis. Diamond burs and polyvinyl siloxane materials inoculated with E. coli was effective after 60 and 90 seconds. The diamond burs and polyvinyl siloxane materials inoculated with B. subtilis was effective after 120 and 180 seconds. CONCLUSION: The atmospheric pressure non-thermal air plasma device was effective in killing both E. coli and B. subtilis, and was more effective in killing E. coli than the UV sterilizer.