Non-Thermal Atmospheric Pressure Plasma Application in Endodontics.

The failure of endodontic treatment is frequently associated with the presence of remaining microorganisms, mainly due to the difficulty of eliminating the biofilm and the limitation of conventional irrigation solutions. Non-thermal atmospheric pressure plasma (NTPP) has been suggested for many applications in the medical field and can be applied directly to biological surfaces or indirectly through activated liquids. This literature review aims to evaluate the potential of NTPP application in Endodontics. A search in the databases Lilacs, Pubmed, and Ebsco was performed. Seventeen manuscripts published between 2007 and 2022 that followed our established inclusion criteria were found. The selected manuscripts evaluated the use of NTPP regarding its antimicrobial activity, in the direct exposure and indirect method, i.e., plasma-activated liquid. Of these, 15 used direct exposure. Different parameters, such as working gas and distance from the apparatus to the substrate, were evaluated in vitro and ex vivo. NTPP showed a disinfection property against important endodontic microorganisms, mainly Enterococcus faecalis and Candida albicans. The antimicrobial potential was dependent on plasma exposure time, with the highest antimicrobial effects over eight minutes of exposure. Interestingly, the association of NTPP and conventional antimicrobial solutions, in general, was shown to be more effective than both treatments separately. This association showed antimicrobial results with a short plasma exposure time, what could be interesting in clinical practice. However, considering the lack of standardization of the direct exposure parameters and few studies about plasma-activated liquids, more studies in the area for endodontic purposes are still required.

Effect of radiotherapy on the differentiation and osteogenic activity of mesenchymal stem cells on dental implants / Efeito da radioterapia na diferenciação e atividade osteogênica de células-tronco mesenquimais em implantes dentários

Objective: to evaluate the differentiation and gene expression of transcripts related to osteogenesis in a primary culture of Mesenchymal Stem Cells (MSCs) derived from rat femurs submitted to radiotherapy and the installation of pure titanium implants. Material and Methods: fifty-four rats received titanium implants in both femurs and were divided into three groups: Control: implant surgery (C); Implant + immediate irradiation (IrI), and Implant + late irradiation (IrL). Euthanasia occurred 3, 14, and 49 days after surgery. The bone marrow MSCs from the femurs were isolated and cultivated. The cell viability, total protein content, alkaline phosphatase (ALP) activity, and the formation of mineralization nodules and cellular genotoxicity were analyzed. The gene expression of Alkaline Phosphatase (phoA), Collagen 1 (COL1), Runt-related transcription factor 2 (RUNX2), Osterix (OSX), Osteopontin (OPN), Integrin ß1(ITGB1), Bone Sialoprotein (BSP), Osteonectin (SPARC), Osteocalcin (Bglap), Transforming Growth Factor ß-type (TGF-ß), Granulocyte Macrophage Colony Stimulating Factor (GM-CSF), Interleukin-6 (IL-6), Apolipoprotein E (APOE) and Prostaglandin E2 synthase (PGE2) were evaluated by qRT- PCR. Results: ionizing radiation suppresses the gene expression of essential transcripts for bone regeneration, as well as cellular viability, as observed in the IrI and IrL groups. Conclusion: although this can lead to the loss of osseointegration and failure of the implant, the MSCs showed more activity at 49 days than at 3 and 14 days. (AU)

Objetivo: avaliar a diferenciação e expressão gênica de transcritos relacionados à osteogênese em cultura primária de MSCs derivadas de fêmures de ratos submetidos à radioterapia e instalação de implantes de titânio puro. Material e Métodos: cinquenta e quatro ratos receberam implantes de titânio em ambos os fêmures e foram divididos em três grupos: Controle: cirurgia de implante (C); Implante + irradiação imediata (IrI) e Implante + irradiação tardia (IrL). A eutanásia ocorreu 3, 14 e 49 dias após a cirurgia. As MSCs de medula óssea dos fêmures foram isoladas e cultivadas. Foram analisadas a viabilidade celular, teor de proteína total, atividade da fosfatase alcalina (ALP), formação de nódulos de mineralização e genotoxicidade celular. A expressão gênica de Fosfatase Alcalina (phoA), Colágeno 1 (COL1), fator de transcrição relacionado a Runt 2 (RUNX2), Osterix (OSX), Osteopontina (OPN), Integrina ß1 (ITGB1), Sialoproteína Óssea (BSP), Osteonectina (SPARC), Osteocalcina (Bglap), Fator de Crescimento Transformador tipo ß (TGF-ß), Fator Estimulante de Colônia de Granulócitos-Macrófagos (GM-CSF), Interleucina-6 (IL-6), Apolipoproteína E (APOE) e Prostaglandina E2 sintase (PGE2) foram avaliados por qRT-PCR. Resultados: a radiação ionizante suprime a expressão gênica de transcritos essenciais para a regeneração óssea, bem como a viabilidade celular, como observado nos grupos IrI e IrL. Conclusão:embora isso possa levar à perda da osseointegração e falha do implante, as MSCs apresentaram maior atividade aos 49 dias do que aos 3 e 14 dias (AU)

Applications of Plasma-Activated Water in Dentistry: A Review.

The activation of water by non-thermal plasma creates a liquid with active constituents referred to as plasma-activated water (PAW). Due to its active constituents, PAW may play an important role in different fields, such as agriculture, the food industry and healthcare. Plasma liquid technology has received attention in recent years due to its versatility and good potential, mainly focused on different health care purposes. This interest has extended to dentistry, since the use of a plasma-liquid technology could bring clinical advantages, compared to direct application of non-thermal atmospheric pressure plasmas (NTAPPs). The aim of this paper is to discuss the applicability of PAW in different areas of dentistry, according to the published literature about NTAPPs and plasma-liquid technology. The direct and indirect application of NTAPPs are presented in the introduction. Posteriorly, the main reactors for generating PAW and its active constituents with a role in biomedical applications are specified, followed by a section that discusses, in detail, the use of PAW as a tool for different oral diseases.

Estudo do potencial de reposicionamento do composto auranofina no controle de infecções por Candida albicans / Study on the potential for the repositioning of auranofin in the control of Candida albicans infections

A ocorrência crescente de resistência antifúngica, a toxicidade, além do pequeno espectro de ação dos antifúngicos convencionais, limita o número de alternativas terapêuticas para doenças causadas por leveduras do gênero Candida. Uma das frentes de pesquisa é a proposta de novos usos para drogas existentes chamada de reposicionamento, que diminui o tempo e esforço na busca de novos compostos eficazes. Neste contexto, o presente estudo tem como objetivo avaliar o potencial antifúngico e os mecanismos de ação do composto auranofina contra a espécie Candida albicans, além da toxicidade in vivo. Foram utilizadas cepas padrões de C. albicans (SC5314, ATCC 18804) e as concentrações inibitória mínima (CIM) e fungicida mínima (CFM) foram determinadas. Os mecanismos de ação dos compostos foram avaliados sobre a estrutura celular de C. albicans, com verificação de alterações na morfologia, na parede celular, sobre os fatores de virulência de C. albicans, como transição levedura-hifa e produção de exoenzimas, além do efeito do composto sobre o metabolismo de C. albicans e efeito antifúngico sob condições de estresse osmótico. Para avaliação da toxicidade das concentrações efetivas de auranofina in vivo, foi utilizado o modelo invertebrado, Drosophila melanogaster. Os dados obtidos no ensaio de transição levedura-hifa foram avaliados pelos testes ANOVA e de Tukey e os testes Kruskal-Wallis e de Dunn. foram utilizados na análise do efeito de auranofina sobre o metabolismo fúngico. O nível de significância para todos os testes foi de 5%. Foram verificadas concentrações inibitória e fungicida de auranofina sobre C. albicans. Apesar da ausência de efeitos sobre fatores de virulência, auranofina causou redução no metabolismo fúngico e no crescimento fúngico sob estresse osmótico, sugerindo, nesse caso, um possível efeito direto ou indireto na membrana celular fúngica. Além disso, nas concentrações efetivas não foi observada toxicidade relevante in vivo. Os resultados demonstraram, portanto, que auranofina tem potencial para seu reposicionamento como antifúngico, no entanto, mais estudos são necessários para mais esclarecimentos e utilização adequada do medicamento (AU).

The increasing occurrence of antifungal resistance, toxicity, in addition to the small spectrum of action of conventional antifungals, limits the number of therapeutic alternatives for diseases caused by yeasts of the genus Candida. One of the research fronts is the proposal of new uses for existing drugs called repositioning, which reduces the time and effort in the search for new effective compounds. In this context, the present study aims to evaluate the antifungal potential and mechanisms of action of the auranofin compound against Candida albicans, in addition to in vivo toxicity. Standard strains of C. albicans (SC5314, ATCC 18804) were used and minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were determined. The mechanisms of action of the compounds were evaluated on the cellular structure of C. albicans, with verification of changes in morphology, in the cell wall, on the virulence factors of C. albicans, such as yeast-hypha transition and production of exoenzymes, in addition to the effect of the compound on the metabolism of C. albicans and antifungal effect under osmotic stress conditions. To evaluate the toxicity of effective concentrations of auranofin in vivo, the invertebrate model, Drosophila melanogaster, was used. The data obtained in the yeast-hypha transition assay were evaluated by the ANOVA and Tukey tests and the KruskalWallis and Dunn tests. were used to analyze the effect of auranofin on fungal metabolism. The significance level for all tests was 5%. Inhibitory and fungicidal concentrations of auranofin were verified on C. albicans. Despite the absence of effects on virulence factors, auranofin caused a reduction in fungal metabolism and fungal growth under osmotic stress, suggesting, in this case, a possible direct or indirect effect on the fungal cell membrane. Furthermore, at effective concentrations, no relevant in vivo toxicity was observed. The results showed, therefore, that auranofin has the potential for its repositioning as an antifungal, however, more studies are needed for further clarification and proper use of the drug (AU).

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.

Understanding SARS CoV-2 biology to win COVID-19 battle / Entendendo a biologia do SARS CoV-2 para vencer a batalha contra a COVID-19

This review highlights the main findings on the biology of SARS CoV-2 and the strategies to combat COVID 19 pandemic. Since the initial outbreak in China on December 2019, the international scientific community joined efforts in an unprecedent public health battle. In late May 2020, 5 204 508 cases and 337 687 deaths have been reported by World Health Organization, with higher number of cases in Europe and Americas. SARS-CoV-2 was described as a novel variant from the coronavirus family and its genome was sequenced within a few months while COVID 19 quickly spread worldwide. The main cell receptor (angiotensin converting enzyme 2) was identified as involved in the invasion of host cells. As a result of the findings from cell biology, immunology and clinical studies, the pathogenesis of the virus started to be understood but it has been not fully elucidated so far. While a massive effort for the development of a vaccine is on course, preventive protocols for infection control have been proposed. Many studies on the discovering of effective therapeutic protocols have been developed, particularly on the redirection of already approved substances, but no gold standard treatment was established until now. An overview on the envisioned socioeconomic and politic impacts suggest that our society will be transformed after COVID 19 pandemia. As a result, deep changes in science, politics, socioeconomic and healthcare priorities shall appear in post-pandemia agenda.(AU)

Esta revisão destaca os principais relatos sobre a biologia do SARS CoV-2 e as estratégias para combater a epidemia de COVID 19. Desde o surto inicial na China, em dezembro de 2019, a comunidade científica internacional uniu esforços em uma batalha de saúde pública sem precedentes. No final de maio de 2020, 5.204.508 casos e 337.687 mortes foram reportadas pela Organização Mundial da Saúde, com maior número de casos na Europa e nas Américas. O SARS-CoV-2 foi descrito como uma nova variante da família coronavírus e seu genoma foi sequenciado em poucos meses, enquanto a COVID 19 se espalhou rapidamente pelo mundo. O receptor celular principal (angiotensin converting enzyme 2) foi identificado como envolvido no processo de invasão às células do hospedeiro. Como resultado das descobertas da biologia celular, imunologia e estudos clínicos, a patogênese do vírus começou a ser entendida mas não está completamente elucidada até o momento. Enquanto um grande esforço para o desenvolvimento da vacina está em curso, protocolos preventivos para o controle de infeção foram propostos. Muitos estudos para o estabelecimento de protocolos terapêuticos efetivos têm sido desenvolvidos, particularmente no reposicionamento de substâncias já aprovadas, porém nenhum tratamento padrão foi estabelecido até o momento. Uma visão geral dos impactos políticos e socioeconômicos previstos sugerem que nossa sociedade será transformada após a pandemia de COVID 19. Como resultado, mudanças profundas nas prioridades da ciência, política, área socioeconômica e saúde deverão surgir na agenda póspandemia.(AU)

Titanium alloys: in vitro biological analyzes on biofilm formation, biocompatibility, cell differentiation to induce bone formation, and immunological response.

Biological effects of titanium (Ti) alloys were analyzed on biofilms of Candida albicans, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans, and Streptococcus sanguinis, as well as on osteoblast-like cells (MG63) and murine macrophages (RAW 264.7). Standard samples composed of aluminum and vanadium (Ti-6Al-4V), and sample containing niobium (Ti-35Nb) and zirconium (Ti-13Nb-13Zr) were analyzed. Monomicrobial biofilms were formed on the Ti alloys. MG63 cells were grown with the alloys and the biocompatibility (MTT), total protein (TP) level, alkaline phosphatase (ALP) activity, and mineralization nodules (MN) formation were verified. Levels of interleukins (IL-1ß and IL-17), tumor necrosis factor alpha (TNF-α), and oxide nitric (NO) were checked, from RAW 264.7 cells supernatants. Data were statically analyzed by one-way analysis of variance (ANOVA) and Tukey's test, or T-test (P ≤ 0.05). Concerning the biofilm formation, Ti-13Nb-13Zr alloy showed the best inhibitory effect on E. faecalis, P. aeruginosa, and S. aureus. And, it also acted similarly to the Ti-6Al-4V alloy on C. albicans and Streptococcus spp. Both alloys were biocompatible and similar to the Ti-6Al-4V alloy. Additionally, Ti-13Nb-13Zr alloy was more effective for cell differentiation, as observed in the assays of ALP and MN. Regarding the stimulation for release of IL-1ß and TNF-α, Ti-35Nb and Ti-13Nb-13Zr alloys inhibited similarly the synthesis of these molecules. However, both alloys stimulated the production of IL-17. Additionally, all Ti alloys showed the same effect for NO generation. Thus, Ti-13Nb-13Zr alloy was the most effective for inhibition of biofilm formation, cell differentiation, and stimulation for release of immune mediators.

Influence of Chronic Alcohol Use on Osteoblastic Differentiation of Bone Marrow Cells, Bone Properties, and Hepatic and Renal Morphology of Rats.

Chronic alcohol exposure can affect the osteoblastic activity and the proliferation and differentiation of cells due to its toxic effect, which can affect negatively bone repair and bone microarchitecture. The aim of this study was to evaluate the effects of chronic use of 20% alcohol on rats regarding osteoblastic differentiation, extrinsic and intrinsic properties of the tibia, and hepatic and renal morphology. Wistar rats were divided into three groups (n = 9) in accordance with a 24-week diet. After euthanasia, kidneys, liver, and tibias were removed for analysis and femurs mesenchymal cells were collected. The results showed that chronic use of 20% alcohol influenced neither the alkaline phosphatase production nor total protein (p > 0.05) in rats, with similar formation of nodules in all groups (p > 0.05). However, significant changes in the liver and kidneys and adverse effects on the mechanical properties of the tibia were observed. According to the results, it can be concluded that the chronic use of alcohol for 24 weeks had no negative influence on the activity and differentiation of osteoblasts, but the mechanical properties of the tibia were impaired and the organs responsible for metabolism and excretion were also affected due to the consumption of alcohol.

Efeito modulador da radiação ionizante sobre citocinas sanguíneas e células do tecido ósseo na interface osso-implante / Modulating effect of ionizing radiation on blood cytokines and bone tissue cells at the bone-implant interface

Implantes osseointegrados são considerados efetivos como tratamento reabilitador. Contudo, vários fatores podem prejudicar o sítio receptor, entre eles, a radiação ionizante. Entretanto, os mecanismos pelos quais estes eventos acontecem ainda não foram completamente esclarecidos. O objetivo neste estudo foi avaliar o efeito modulador da radioção ionizante, simulando uma dose total de um tratamento radioterápico convencional para pacientes oncológicos, nos níveis de citocinas sanguíneas e na remodelação óssea da interface ao redor do implante. Foram utilizados 45 ratos que receberam implantes rosqueados de titânio grau V nos fêmures direito. Os animais foram divididos em 3 grupos: a) Grupo Sem-Irradiação (S-Ir): grupo controle apenas com implante. b) Grupo Irradiação Posterior (IrPos): implante + irradiação; c) Grupo Irradiação Prévia (IrPrev): irradiação + implante. Os animais dos grupos IrPos e IrPrev foram submetidos a irradiação em 2 etapas fracionadas de 15 Gy. Nos períodos de 3 dias, 2 semanas e 7 semanas após o último procedimento, 05 animais foram eutanasiados aleatoriamente por grupo. Os níveis séricos de TNF-ɑ, IL-1ß e IL-10 foram mensurados a partir do sangue coletado previamente ao momento da eutanásia pelo método imunoenzimático (ELISA). As peças contendo os implantes foram submetidos à marcação imunohistoquímica utilizando os marcadores para TRAP e osteocalcina (OC). O teste ANOVA foi utilizado para análise estatística e quando necessário foi aplicado o teste de comparação múltipla de Tukey (p<0,05). O grupo IrPos exibiu diferença estatística (p<0,05) com S-Ir e IrPrev nos valores de TNF-α em 2 e 7 semanas, enquanto IrPrev diferiu estatisticamente (p<0,05) de S-Ir nos valores de IL-10, em 3 dias. A análise imuno-histoquímica da interface osso-implante, demonstrou valores mais altos de TRAP e OC nos grupos irradiados, com diferença estatística (p<0,05), entre os valores de TRAP de S-Ir e IrPos em 3 dias e entre S-Ir e IrPrev em todos os períodos, e de OC entre S-Ir e IrPos em 3 dias e entre S-Ir e IrPrev em 2 semanas. Em suma, os resultados desse estudo indicaram que a radiação ionizante alterou produções de citocinas sanguíneas pró e anti-inflamatórias após lesão cirúrgica de colocação do implante e influenciou na expressão de proteínas envolvidas na remodelação óssea(AU)

Osseointegrated implants are considered effective as a rehabilitative treatment. However, several factors may impair the receptor site, including ionizing radiation. However, the mechanisms by which these events occur have not yet been fully elucidated. The objective of this study was to evaluate the modulating effect of radiotherapy, simulating a total dose of a conventional ionizing radiation treatment for cancer patients, blood cytokine levels and bone remodeling of the interface around the implant. Forty-five rats were submitted to grade V titanium implants in the right femurs. The animals were divided into three groups: a)No Irradiation group (N-Ir): control group with only the implant b) Previous irradiation group (Prev-Ir): implant + irradiation; c) Posterior Irradiation group (Pos-Ir): irradiation + implant. Pos-Ir and Prev-Ir groups were irradiated in 2 fractional stages of 15 Gy. At 3 days, 2 weeks and 7 weeks after the last procedure, 05 animals were randomly euthanized per group. Serum levels of TNF-ɑ, IL-1ß and IL-10 were measured from blood collected prior to euthanasia using the enzyme-linked immunosorbent assay (ELISA). The pieces containing the implants were subjected to immunohistochemical labeling using the markers for TRAP and osteocalcin (OC). The ANOVA test was used for statistical analysis and when necessary the Tukey multiple comparison test (p <0.05) was applied. The Pos-Ir group exhibited a statistical difference (p <0.05) with N-Ir and Prev-Ir in TNF-α values at 2 and 7 weeks, whereas Prev-Ir differed statistically (p <0.05) from N-Ir in IL-10 values, in 3 days. The immunohistochemical analysis of the bone-implant interface demonstrated higher values of TRAP and OC in the irradiated groups, with a statistical difference (p <0.05) between the values of TRAP of N-Ir and Pos-Ir in 3 days and between N-Ir and Prev-Ir in all periods, and OC between N-Ir and Pos-Ir in 3 days and between N-Ir and Prev-Ir in 2 weeks. In summary, the results of this study indicated that irradiation altered productions of pro and antiinflammatory blood cytokines after surgical lesion of implant placement and influenced the expression of proteins involved in bone remodeling(AU)