Cold Atmospheric Plasma Jet as a Possible Adjuvant Therapy for Periodontal Disease

Due to the limitations of traditional periodontal therapies, and reported cold atmospheric plasma anti-inflammatory/antimicrobial activities, plasma could be an adjuvant therapy to periodontitis. Porphyromonas gingivalis was grown in blood agar. Standardized suspensions were plated on blood agar and plasma-treated for planktonic growth. For biofilm, dual-species Streptococcus gordonii + P. gingivalis biofilm grew for 48 h and then was plasma-treated. XTT assay and CFU counting were performed. Cytotoxicity was accessed immediately or after 24 h. Plasma was applied for 1, 3, 5 or 7 min. In vivo: Thirty C57BI/6 mice were subject to experimental periodontitis for 11 days. Immediately after ligature removal, animals were plasma-treated for 5 min once-Group P1 (n = 10); twice (Day 11 and 13)-Group P2 (n = 10); or not treated-Group S (n = 10). Mice were euthanized on day 15. Histological and microtomography analyses were performed. Significance level was 5%. Halo diameter increased proportionally to time of exposure contrary to CFU/mL counting. Mean/SD of fibroblasts viability did not vary among the groups. Plasma was able to inhibit P. gingivalis in planktonic culture and biofilm in a cell-safe manner. Moreover, plasma treatment in vivo, for 5 min, tends to improve periodontal tissue recovery, proportionally to the number of plasma applications

Effect of Cold Atmospheric Plasma Jet Associated to Polyene Antifungals on Candida albicans Biofilms

The increasing incidence of antifungal resistance represents a great challenge in the medical area and, for this reason, new therapeutic alternatives for the treatment of fungal infections are urgently required. Cold atmospheric plasma (CAP) has been proposed as a promising alternative technique for the treatment of superficial candidiasis, with inhibitory effect both in vitro and in vivo. However, little is known on the association of CAP with conventional antifungals. The aim of this study was to evaluate the effects of the association between CAP and conventional polyene antifungals on Candida albicans biofilms. C. albicans SC 5314 and a clinical isolate were used to grow 24 or 48 h biofilms, under standardized conditions. After that, the biofilms were exposed to nystatin, amphotericin B and CAP, separately or in combination. Different concentrations of the antifungals and sequences of treatment were evaluated to establish the most effective protocol. Biofilms viability after the treatments was compared to negative control. Data were compared by One-way ANOVA and post hoc Tukey (5%). The results demonstrate that 5 min exposure to CAP showed more effective antifungal effect on biofilms when compared to nystatin and amphotericin B. Additionally, it was detected that CAP showed similar (but smaller in magnitude) effects when applied in association with nystatin and amphotericin B at 40 µg/mL and 60 µg/mL. Therefore, it can be concluded that the application of CAP alone was more effective against C. albicans biofilms than in combination with conventional polyene antifungal agents

Cold Atmospheric Pressure Plasma Is Effective against P. gingivalis (HW24D-1) Mature Biofilms and Non-Genotoxic to Oral Cells

The effects of helium cold atmospheric pressure plasma (He-CAPP) jet on Porphyromonas gingivalis (HW24D-1) biofilm, on human gingival fibroblasts (HGF) and human gingival keratinocytes (OBA-9) were assessed. Standardized suspension of P. gingivalis was obtained, and biofilms were grown anaerobically for 48 h. After exposition to He-CAPP, the biofilm viability was evaluated by XTT assay. HGF were grown at 37 °C, in an CO2 chamber in DMEM, while OBA-9 cells were cultured in keratinocyte serum-free medium. After 24 h, plates were exposed to He-CAPP for 1 to 7 min. Plasma was generated using a commercial AC power supply with amplitude modulated signal (voltage amplitude of 20 kVp-p, frequency of 31.0 kHz and duty cycle of 22%). The corresponding discharge power was 0.6W at He flow rate of 1 L/min. DNA damage was accessed by static cytometry. Data were analyzed by GraphPad Prism (p < 0.05). Significant reductions in P. gingivalis viability in relation to non-treated groups were detected (p < 0.0001), directly proportional to exposure time. Treated groups were slightly aneuploid after 5- and 7-min treatment in HGF, and for 3 min in OBA-9 cells, with 1.2 DNA index mean. Helium cold atmospheric pressure plasma jet showed inhibitory effect on P. gingivalis mature biofilm and was not genotoxic for epithelial gingival cells and human oral fibroblasts

Jato de plasma frio em pressão atmosférica para tratamento de materiais e esterilização

Atmospheric pressure plasma jets (APPJs) are capable of generating cold plasma in open environment. The gas flow from the jet carries the plasma to the outside region. Because of its enhanced chemistry and ability of treating 3D objects, APPJs are suitable for applications in many fields of industry and technology. In this work, two different applications of plasma jets were investigated. In the first part, a corona-like plasma jet was used for surface treatment of two polymers, the polypropylene (PP) and the polyethylene terephthalate (PET). The jet was operated with helium and argon gas. The aims of this study are to evaluate the formation of low-molecular-weight oxidized material (LMWOM) on the polymers surface and to determine the optimal treatment conditions. The changes in surface hydrophilicity, chemical composition of polymers surface and the material roughness were analyzed. The results show that the LMWOM formed due to the plasma exposure tends to agglomerate into small mounts on the surface. These structures are weakly bounded to the surface and can be easily removed by rinsing in polar solvents. After washing the treated samples, the polymers partially recover their original wetting characteristics. The jet-to-sample distance was found to be an important parameter that can significantly influence the treatment uniformity. In the second part of this work, a DBD-type plasma jet working in helium was applied for inactivation of microorganisms. The effectiveness of the APPJ was evaluated against three common pathogenic agents, the Gram-positive bacteria Enterococcus faecalis (ATCC 29212), the Gram-negative bacteria Pseudomonas aeruginosa (ATCC 15442) and the yeast Candida albicans (SC 5314). The effect of plasma treatment was evaluated by measuring the inactivation zone diameter. The cell morphological changes were analyzed using scanning ...(Complete abstract click electronic access below)Jatos de plasma em pressão atmosférica (APPJs) são capazes de gerar plumas frias de plasma em espaço aberto. O fluxo de gás, introduzido no jato, carrega o plasma para a região externa. Devido à sua química muito reativa e a habilidade em tratar objetos tridimensionais, os jatos de plasma são adequados para aplicações em vários ramos da indústria e tecnologia. Neste trabalho, duas diferentes aplicações dos APPJs foram investigadas. Na primeira parte, um jato de plasma tipo corona, operando com os gases hélio e argônio, foi utilizado no tratamento de superfície de dois polímeros, o polipropileno (PP) e o politereftalato de etileno (PET). Os objetivos deste estudo são avaliar a formação de estruturas oxidadas de baixo peso molecular (LMWOM) formadas na superfície do material polimérico e determinar as condições ótimas de tratamento. As alterações na molhabilidade da superfície do polímero, na estrutura química e a rugosidade do material foram analisadas. Os resultados mostraram que os LMWOMs, formados devido ao tratamento, tendem a aglomerar sobre a superfície formando pequenas estruturas nodulares. Estas estruturas são fracamente ligadas à superfície podendo ser removidos do material quando a amostra é lavada em líquidos polares. Após a lavagem das amostras, os polímeros tendem a recuperar suas propriedades originais. A distância entre o bocal da seringa e a superfície da amostra se mostrou um parâmetro importante, capaz de influenciar significativamente a uniformidade do tratamento. Na segunda parte deste trabalho, um jato de plasma DBD alimentado com hélio foi utilizado na inativação de microrganismos. A eficiência do jato de plasma foi avaliada contra três agentes patogênicos comuns, a bactéria Gram-positiva Enterococcus faecalis (ATCC 29212), a bactéria Gram-negativa Pseudomonas aeruginosa (ATCC 15442) e ... (Resumo completo, clicar acesso eletrônico abaixo)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Aplicação da descarga por barreira dielétrica (DBD) em diferentes frequências no tratamento de polipropileno

In this work, air dielectric barrier discharge (DBD) operating at two different frequencies (60 Hz and 17 kHz) was used to improve surface properties of polypropylene (PP). The changes in surface hydrophilicity were investigated by contact angle measurements. The modifications in chemical composition of PP surface were studied by X-ray photoelectron spectroscopy (XPS) and Fourier-transformed infrared spectroscopy (FTIR). The PP roughness were analyzed before and after the DBD treatment using atomic force microscopy (AFM). In order to compare the results obtained at different frequencies, the analyses are presented as a function of the deposited energy density. The results show that both DBD treatments led to formation of low-molecular weight oxidized material (LMWOM). It tends to agglomerate into small mounts on the surface, as shown by AFM analyses. These structures are weakly bounded to the surface and can be easily removed by rinsing in polar solvents. After washing the DBD-treated samples, the PP partially recovers its original wetting characteristics. This suggests that oxidation also occurred at deeper and more permanent levels on the PP samples. Comparing both DBD treatments, the 17 kHz process was found to be more efficient in introducing oxygen groups to the PP surfaceNeste trabalho, foi utilizada a descarga por barreira dielétrica (DBD) gerada em ar e em duas frequências diferentes (60 Hz e 17 kHz) para modificar as propriedades de polipropileno (PP). As alterações na molhabilidade da superfície do polímero foram investigadas utilizando medidas de ângulo de contato. As mudanças na estrutura química causadas pelo tratamento foram estudadas com espectroscopia de fotoelétrons excitados por raios-X (XPS) e espectroscopia em infravermelho por transformada de Fourier (FTIR). A rugosidade do PP foi analisada antes e após os tratamentos utilizando microscopia de força atômica (AFM). Para que os resultados em diferentes frequências possam ser comparados, as análises são apresentadas em função da densidade de energia depositada. Os resultados mostraram que ambos os tratamentos com DBD levam à formação de materiais oxidados de baixo peso molecular (LMWOM). Estes tendem a aglomerar sobre a superfície formando pequenas estruturas nodulares, como mostra a análise com AFM, e são fracamente ligados à superfície podendo ser removidos do material quando a amostra é lavada em líquidos polares após o tratamento. Após a lavagem das amostras, o PP tende a recuperar suas propriedades iniciais, mas não as recupera totalmente. Isso sugere que a oxidação causada pelo plasma também ocorre em camadas mais profundas do material. Comparando as duas frequências utilizadas, o tratamento em alta frequência (17 kHz) se mostrou mais eficiente em introduzir grupos à superfície do P

Inactivation of candida albicans by cold atmospheric pressure plasma jet

Nonthermal atmospheric pressure plasma jets (APPJs) are characterized by very reactive chemistry without the need of elevated temperatures. Also, plasma jets are capable of producing cold plasma plumes that are not spatially confined by electrodes, which makes them very attractive for biomedical applications. In this paper, we investigate the antimicrobial efficiency of a simple plasma jet device operating with pure He as working gas. The device was driven by an ac power supply operated at 31.0 kHz, 13.0 kV amplitude with mean power around 1.8 W. The jet was directed perpendicularly on a standard Petri dish (O90 mm x 15 mm) filled with agar. The jet fungicidal efficiency was tested against Candida albicans (reference strains SC 5314 and ATCC 18804) and five clinical isolates from previously obtained denture stomatitis lesions. In this paper, the effects of treatment time and distance to the target were evaluated. In most treatments the samples did not have direct contact with the plasma plume; therefore, the reactive oxygen species produced by interaction between the plasma jet and ambient air were the principal inactivate agent.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Amplitude-modulated cold atmospheric pressure plasma jet for treatment of oral candidiasis: In vivo study.

The aim of this study was to establish an effective and safe protocol for in vivo oral candidiasis treatment with atmospheric plasma jets. A novel amplitude-modulated cold atmospheric pressure plasma jet (AM-CAPPJ) device, operating with Helium, was tested. In vitro assays with Candida albicans biofilms and Vero cells were performed in order to determine the effective parameters with low cytotoxicity. After the determination of such parameters, the protocol was evaluated in experimentally induced oral candidiasis in mice. AM-CAPPJ could significantly reduce the viability of C. albicans biofilms after 5 minutes of plasma exposure when compared to the non-exposed group (p = 0.0033). After this period of exposure, high viability of Vero cells was maintained (86.33 ± 10.45%). Also, no late effects on these cells were observed after 24 and 48 hours (83.24±15.23% and 88.96±18.65%, respectively). Histological analyses revealed significantly lower occurrence of inflammatory alterations in the AM-CAPPJ group when compared to non-treated and nystatin-treated groups (p < 0.0001). Although no significant differences among the values of CFU/tongue were observed among the non-treated group and the groups treated with AM-CAPPJ or nystatin (p = 0.3201), histological analyses revealed marked reduction in candidal tissue invasion. In conclusion, these results point out to a clinical applicability of this protocol, due to the simultaneous anti-inflammatory and inhibitory effects of AM-CAPPJ with low cytotoxicity

Helium Cold Atmospheric Plasma Causes Morphological and Biochemical Alterations in <i>Candida albicans</i> Cells

(1) Background: Previous studies reported the promising inhibitory effect of cold atmospheric plasma (CAP) on Candida albicans. However, the exact mechanisms of CAP’s action on the fungal cell are still poorly understood. This study aims to elucidate the CAP effect on C. albicans cell wall, by evaluating the alterations on its structure and biochemical composition; (2) Methods: C. albicans cells treated with Helium-CAP were analyzed by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) in order to detect morphological, topographic and biochemical changes in the fungal cell wall. Cells treated with caspofungin were also analyzed for comparative purposes; (3) Results: Expressive morphological and topographic changes, such as increased roughness and shape modification, were observed in the cells after CAP exposure. The alterations detected were similar to those observed after the treatment with caspofungin. The main biochemical changes occurred in polysaccharides content, and an overall decrease in glucans and an increase in chitin synthesis were detected; (4) Conclusions: Helium-CAP caused morphological and topographic alterations in C. albicans cells and affected the cell wall polysaccharide content

Microscopic images of dorsal surface of <i>C</i>. <i>albicans</i>-infected tongues 24 hours after AM-CAPPJ exposure.

<p>(1) HE-stained; (2) PAS-stained; (A) candidiasis induced and non-treated group; (B) plasma jet-treated; (C) nystatin-treated; (D) Scores (median values and ranges) attributed to the inflammatory alterations (column 1) and tissue invasion (column 2) 24 hours after exposure to AM-CAPPJ.</p