RESUMO
Thymic stromal cells (TSCs) are critical regulators of T cell tolerance, but their basic biology has remained under-characterized because they are relatively rare and difficult to isolate. Recent work has revealed that constitutive autophagy in TSCs is required for self-antigen presentation and central T cell tolerance induction; however, the mechanisms regulating constitutive autophagy in TSCs are not well understood. Hydrogen peroxide has been shown to increase autophagy flux in other tissues, and we previously identified conspicuously low expression of the hydrogen peroxide-quenching enzyme catalase in TSCs. We investigated whether the redox status of TSCs established by low catalase expression regulates their basal autophagy levels and their capacity to impose central T cell tolerance. Transgenic overexpression of catalase diminished autophagy in TSCs and impaired thymocyte clonal deletion, concomitant with increased frequencies of spontaneous lymphocytic infiltrates in lung and liver and of serum antinuclear antigen reactivity. Effects on clonal deletion and autoimmune indicators were diminished in catalase transgenic mice when autophagy was rescued by expression of the Becn1F121A/F121A knock-in allele. These results suggest a metabolic mechanism by which the redox status of TSCs may regulate central T cell tolerance.
Assuntos
Autofagia , Tolerância Imunológica , Timo , Alelos , Animais , Autofagia/genética , Autofagia/imunologia , Proteína Beclina-1/genética , Catalase/genética , Peróxido de Hidrogênio/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Camundongos Transgênicos , Oxirredução , Células Estromais/imunologia , Timo/citologia , Timo/imunologiaRESUMO
The objective of this study was to analyze the antitumor activity of a hydrogel loaded with lipophilic bismuth nanoparticles on human cervical, prostate, and colon cancer cell lines. The effect of lipophilic bismuth nanoparticles on the viability of cancer cell lines (HeLa, DU145, and HCT-116) and non-cancer lung fibroblasts (HLF; LL 47[MaDo]) was determined with the MTT cell viability assay and compared with known antineoplastic drugs. The biocompatibility at an organismal level was verified in a murine model by histological examination. A lipophilic bismuth nanoparticle hydrogel at 50 µM time-dependently inhibited the growth of the three cancer cell lines, in a time-dependent way. A 1-hour exposure to 250 µM lipophilic bismuth nanoparticle hydrogel, inhibited the growth of the three cancer cell lines. The in-vitro efficacy of lipophilic bismuth nanoparticle was similar to the one of docetaxel and cisplatin, but without inhibiting the growth of non-cancer control cells. Histology confirmed the biocompatibility of lipophilic bismuth nanoparticles as there were no signs of cytotoxicity or tissue damage in any of the evaluated organs (kidney, liver, brain, cerebellum, heart, and jejunum). In conclusion, a lipophilic bismuth nanoparticle hydrogel is an innovative, low-cost alternative for the topical treatment of cervicouterine, prostate, and colon human cancers.
Assuntos
Antineoplásicos/farmacologia , Bismuto/farmacologia , Neoplasias do Colo/tratamento farmacológico , Nanopartículas/química , Neoplasias da Próstata/tratamento farmacológico , Neoplasias do Colo do Útero/tratamento farmacológico , Animais , Bismuto/química , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Feminino , Células HeLa , Humanos , Hidrogéis/química , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias da Próstata/patologia , Neoplasias do Colo do Útero/patologiaRESUMO
Bismuth lipophilic nanoparticles (BisBAL NPs) and cetylpyridinium chloride (CPC) are antineoplastic and antimicrobial in vitro. As a next pre-clinical step, a clinically viable dosage form for vaginal application was developed. Compendial pharmacopeial tests (mass uniformity, disintegration, and compressive mechanics) and inductively coupled plasma optical emission spectroscopy were conducted on in-house developed glycerinated gelatin (60:15 v/w) vaginal ovules containing BisBAL NP-CPC. The antimycotic activity of BisBAL NP-CPC vaginal ovules was analyzed using disk diffusion and cell viability XTT assays. The antitumor properties of BisBAL NP-CPC vaginal ovules were assessed by cell viability MTT tests. BisBAL NP-CPC and drug-free vaginal ovules deposited into ex vivo porcine vaginas disaggregated without signs of adverse cytotoxicity within the timespan of clinical efficacy. BisBAL NP-CPC vaginal ovules demonstrated antifungal efficacy comparable to miconazole: C. albicans growth inhibition haloes in diffusion tests were 23 ± 0.968 mm (n = 3) for BisBAL NP-CPC and 20.35 ± 0.899 mm (n = 3) for miconazole. Likewise, BisBAL NP-CPC vaginal ovules reduced HeLa cell growth by 81%, outperforming the clinical reference of 500 µM 5-fluouracil, which induced a 70% growth inhibition. BisBAL NP-CPC incorporated into glycerinated gelatin vaginal ovules constitute an innovative drug delivery system for topical antimycotic and anti-cervical carcinoma treatments.
RESUMO
Electrospun membranes (EMs) have a wide range of applications, including use as local delivery systems. In this study, we manufactured a polyurethane Tecoflex™ EM loaded with bismuth-based lipophilic nanoparticles (Tecoflex™ EMs-BisBAL NPs). The physicochemical and mechanical characteristics, along with the antitumor and bactericidal effects, were evaluated using a breast cancer cell line and methicillin-susceptible and resistant Staphylococcus aureus (MRSA). Drug-free Tecoflex™ EMs and Tecoflex™ EMs-BisBAL NPs had similar fiber diameters of 4.65 ± 1.42 µm and 3.95 ± 1.32 µm, respectively. Drug-free Tecoflex™ EMs did not negatively impact a human fibroblast culture, indicating that the vehicle is biocompatible. Tecoflex™ EMs-BisBAL NPs increased 94% more in size than drug-free Tecoflex™ EMs, indicating that the BisBAL NPs enhanced hydration capacity. Tecoflex™ EMs-BisBAL NPs were highly bactericidal against both methicillin-susceptible S. aureus and MRSA clinical isolates, inhibiting their growth by 93.11% and 61.70%, respectively. Additionally, Tecoflex™ EMs-BisBAL NPs decreased the viability of MCF-7 tumor cells by 86% after 24 h exposure and 70.1% within 15 min. Regarding the mechanism of action of Tecoflex™ EMs-BisBAL NPs, it appears to disrupt the tumor cell membrane. In conclusion, Tecoflex™ EMs-BisBAL NPs constitute an innovative low-cost drug delivery system for human breast cancer and postoperative wound infections.
RESUMO
OBJECTIVE: To evaluate the antitumor and antimicrobial properties of an alginate-based membrane (ABM) loaded with bismuth lipophilic nanoparticles (BisBAL NPs) and cetylpyridinium chloride (CPC) on clinically isolated bacteria and a pancreatic cancer cell line. MATERIAL AND METHODS: The BisBAL NP-CPC ABM was characterized using optical and scanning electron microscopy (SEM). The antimicrobial potential was measured using the disk-diffusion assay, and antibiofilm activity was determined through the live/dead assay and fluorescence microscopy. The antitumor activity was analyzed on the pancreatic cell line (Panc 03.27) using the MTT assay and live/dead assay with fluorescence microscopy. RESULTS: After a 24-h exposure (37°C, aerobic conditions), 5 µM BisBAL NP reduced the growth of K. pneumoniae by 77.9%, while 2.5 µM BisBAL NP inhibited the growth of Salmonella, E. faecalis and E. faecium by 82.9%, 82.6%, and 78%, respectively (p < 0.0001). The BisBAL NPs-CPC ABM (at a ratio of 10:1; 500 and 50 µM, respectively) inhibited the growth of all isolated bacteria, producing inhibition halos of 9.5, 11.2, 7, and 10.3 mm for K. pneumoniae, Salmonella, E. faecalis, and E. faecium, respectively, in contrast to the 6.5, 9.5, 8.5, and 9.8 mm obtained with 100 µM ceftriaxone (p < 0.0001). The BisBAL NPs-CPC ABM also reduced bacterial biofilms, with 81.4%, 74.5%, 97.1%, and 79.5% inhibition for K. pneumoniae, E. faecium, E. faecalis, and Salmonella, respectively. Furthermore, the BisBAL NPs-CPC ABM decreased Panc 03.27 cell growth by 76%, compared to 18% for drug-free ABM. GEM-ABM reduced tumoral growth by 73%. The live/dead assay confirmed that BisBAL NPs-CPC-ABM and GEM-ABM were cytotoxic for the turmoral Panc 03.27 cells. CONCLUSION: An alginate-based membrane loaded with BisBAL NP and CPC exhibits dual antimicrobial and antitumoral efficacy. Therefore, it could be applied in cancer treatment and to diminish the occurrence of surgical site infections.
Assuntos
Anti-Infecciosos , Bismuto , Dimercaprol/análogos & derivados , Compostos Organometálicos , Cetilpiridínio/farmacologia , Anti-Infecciosos/farmacologia , Alginatos/farmacologia , Klebsiella pneumoniaeRESUMO
OBJECTIVE: To determine the combined antitumor effect of bismuth lipophilic nanoparticles (BisBAL NP) and cetylpyridinium chloride (CPC) on human lung tumor cells. MATERIAL AND METHODS: The human lung tumor cells A549 were exposed to 1-100 µM BisBAL NP or CPC, either separately or in a 1:1 combination. Cell viability was measured with the PrestoBlue assay, the LIVE/DEAD assay, and fluorescence microscopy. The integrity and morphology of cellular microtubules were analyzed by immunofluorescence. RESULTS: A 24-h exposure to 1 µM solutions reduced A549 growth with 21.5% for BisBAL NP, 70.5% for CPC, and 92.4% for the combination (p < 0.0001), while a 50 µM BisBAL NP/CPC mixture inhibited cell growth with 99% (p < 0.0001). BisBAL NP-curcumin conjugates were internalized within 30 min of exposure and could be traced within the nucleus of tumor cells within 2 h. BisBAL NP, but not CPC, interfered with microtubule organization, thus interrupting cell replication, similar to the action mechanism of docetaxel. CONCLUSION: The growth inhibition of A549 human tumor cells by BisBAL NP and CPC was cumulative as of 1 µM. The BisBAL NP/CPC combination may constitute an innovative and cost-effective alternative for treating human lung cancer.
Assuntos
Neoplasias Pulmonares , Nanopartículas , Humanos , Bismuto , Cetilpiridínio/farmacologia , Neoplasias Pulmonares/tratamento farmacológicoRESUMO
Thymic atrophy reduces naive T cell production and contributes to increased susceptibility to viral infection with age. Expression of tissue-restricted antigen (TRA) genes also declines with age and has been thought to increase autoimmune disease susceptibility. We find that diminished expression of a model TRA gene in aged thymic stromal cells correlates with impaired clonal deletion of cognate T cells recognizing an autoantigen involved in atherosclerosis. Clonal deletion in the polyclonal thymocyte population is also perturbed. Distinct age-associated defects in the generation of antigen-specific T cells include a conspicuous decline in generation of T cells recognizing an immunodominant influenza epitope. Increased catalase activity delays thymic atrophy, and here, we show that it mitigates declining production of influenza-specific T cells and their frequency in lung after infection, but does not reverse declines in TRA expression or efficient negative selection. These results reveal important considerations for strategies to restore thymic function.
Assuntos
Envelhecimento/imunologia , Antígenos/imunologia , Imunidade , Tolerância a Antígenos Próprios/imunologia , Linfócitos T/imunologia , Animais , Antioxidantes/farmacologia , Apolipoproteínas B/metabolismo , Atrofia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Catalase/metabolismo , Suplementos Nutricionais , Imunidade/efeitos dos fármacos , Epitopos Imunodominantes/imunologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Orthomyxoviridae/efeitos dos fármacos , Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/imunologia , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Tolerância a Antígenos Próprios/efeitos dos fármacos , Células Estromais/efeitos dos fármacos , Células Estromais/enzimologia , Linfócitos T/efeitos dos fármacos , Timo/patologiaRESUMO
OBJECTIVE: Analyze the antitumor capacity of cetylpyridinium chloride (CPC) on human breast tumor cells, and the possible action mechanism. MATERIAL AND METHODS: The human breast tumor cells MCF-7 and no-tumor breast cells MCF-10A were exposed to CPC under various condition (concentration and duration). Cell viability was measured with MTT assay, the LIVE/DEAD assay, and fluorescence microscopy. Membrane permeability after CPC exposure was evaluated by Calcein AM assay, mitochondrial morphology with a MitoView staining, and genotoxicity with the comet assay and fluorescence microscopy. RESULTS: CPC was cytotoxic to both MCF-7 and MCF-10A as of a 24-h exposure to 0.1 µM. Cytotoxicity was dose-dependent and reached 91% for MCF-7 and 78% for MCF-10A after a 24-h exposure to 100 µM CPC, which outperformed the positive control doxorubicin in effectiveness and selectivity. The LD50 of CPC on was 6 µM for MCF-7 and 8 µM for MCF-10A, yielding a selectivity index of 1.41. A time response analysis revealed 64% dead cells after only 5 min of exposure to 100 µM CPC. With respect to the action mechanisms, the comet assay did not reveal genome fragmentation. On the other hand, membrane damage was dose-dependent and may also affect mitochondrial morphology. CONCLUSION: Cetylpyridinium chloride inhibits MCF-7 cell growing in a non-selective way as of 5 min of exposure. The action mechanism of CPC on tumor cells involves cell membrane damage without change neither mitochondrial morphology nor genotoxicity.
Assuntos
Antineoplásicos , Neoplasias da Mama , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Sobrevivência Celular , Cetilpiridínio/farmacologia , Feminino , Humanos , Células MCF-7RESUMO
AIM: The objective of this study was to analyze the antitumor effect of BisBAL NP in a mouse melanoma model. MATERIALS AND METHODS: The antitumor activity of BisBAL NP on murine B16-F10 melanoma cells was determined both in vitro (PrestoBlue cell viability assay and Live/Dead fluorescence) and in vivo, in a mouse model, with the following 15-day treatments: BisBAL NP, negative control (PBS), and cell-death control (docetaxel; DTX). Mouse survival and weight, as well as the tumor volume, were recorded daily during the in vivo study. RESULTS: BisBAL NP were homogeneous in size (mean diameter, 14.7 nm) and bismuth content. In vitro, 0.1 mg/mL BisBAL NP inhibited B16-F10 cell growth stronger (88%) than 0.1 mg/mL DTX (82%) (*p<0.0001). In vivo, tumors in mice treated with BisBAL NP (50 mg/kg/day) or DTX (10 mg/kg/day) were 76% and 85% smaller than the tumors of negative control mice (*p<0.0001). The average weight of mice was 18.1 g and no statistically significant difference was detected among groups during the study. Alopecia was only observed in all DTX-treated mice. The survival rate was 100% for the control and BisBAL NP groups, but one DTX- treated mouse died at the end of the treatment period. The histopathological analysis revealed that exposure to BisBAL NP was cytotoxic for tumor tissue only, without affecting the liver or kidney. CONCLUSION: BisBAL NP decreased the tumor growing in a mouse melanoma model without secondary effects, constituting an innovative low-cost alternative to treat melanoma.
Assuntos
Antineoplásicos , Melanoma Experimental , Nanopartículas , Animais , Antineoplásicos/farmacologia , Bismuto/farmacologia , Linhagem Celular Tumoral , Dimercaprol/análogos & derivados , Dimercaprol/farmacologia , Humanos , Melanoma Experimental/tratamento farmacológico , Camundongos , Compostos OrganometálicosRESUMO
OBJECTIVE: To evaluate the effect of the combination of calcium hydroxide (Ca(OH)2) and a novel electrolyzed superoxidized solution at neutral pH, known as OxOral® on Enterococcus faecalis growth in root canals. METHODS: Sixty human teeth were used, from which root canals were infected and randomly divided into the following treatment groups: saline solution, saline solution plus Ca(OH)2, OxOral®, and OxOral® plus Ca(OH)2. RESULTS: A permanent reduction in bacterial growth was observed at days 1, 6, 12, and 18 after OxOral® plus Ca(OH)2 treatment from 4.4 ± 0.074 log10 CFU/mL to 0.0 ± 0.001 log10 CFU/mL. In addition, alkaline conditions maintenance was observed from application time (pH = 12.2 ± 0.033) to 18 d posttreatment (pH = 12.6 ± 0.083). CONCLUSION: The combination of OxOral® and Ca(OH)2 provides an alkaline pH and inhibits E. faecalis growth into the root canals. Our study opens the possibility for further research on the use of OxOral® in endodontic therapy.
Assuntos
Anti-Infecciosos/administração & dosagem , Hidróxido de Cálcio/administração & dosagem , Cavidade Pulpar/efeitos dos fármacos , Cavidade Pulpar/microbiologia , Enterococcus faecalis/efeitos dos fármacos , Peróxido de Hidrogênio/administração & dosagem , Enterococcus faecalis/crescimento & desenvolvimento , Humanos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Irrigantes do Canal Radicular/administração & dosagem , Irrigantes do Canal Radicular/química , Tratamento do Canal Radicular/métodos , SoluçõesRESUMO
The objective of this work was to analyze the antimicrobial and antibiofilm activities of bismuth lipophilic nanoparticles (BisBAL NPs) incorporated into chitosan-based membranes. Chitosan-based membranes were homogeneously embedded with BisBAL NPs, confirming the bismuth presence by scanning electron microscopy. The tensile strength of chitosan-based membrane alone or with BisBAL NPs showed similar results as elongation, suggesting that BisBAL NP addition did not affect membrane mechanical properties. Chitosan-based membranes complemented with 100 µM of BisBAL NPs caused a complete inhibition of biofilm formation and a 90-98% growth inhibition of six different oral pathogens. Cytotoxicity studies revealed that 80% of human gingival fibroblasts were viable after a 24-h exposure to the chitosan-based membrane with 100 µM of BisBAL NPs and collagen. Altogether, we conclude that the biological properties of chitosan-based membranes supplemented with BisBAL NPs could be a very interesting option for tissue regeneration.
Assuntos
Anti-Infecciosos , Quitosana , Nanopartículas , Antibacterianos , Bismuto , HumanosRESUMO
Atrophy of the thymus, the primary site of T lymphocyte generation, is a hallmark of the aging immune system. Age-associated thymic atrophy results in diminished output of new, naïve T cells, with immune sequelae that include diminished responses to novel pathogenic challenge and vaccines, as well as diminished tumor surveillance. Although a variety of stimuli are known to regulate transient thymic atrophy, mechanisms governing progressive age-associated atrophy have been difficult to resolve. This has been due in part to the fact that one of the primary targets of age-associated thymic atrophy is a relatively rare population, thymic stromal cells. This review focuses on changes in thymic stromal cells during aging and on the contributions of periodic, stochastic, and progressive causes of thymic atrophy.
Assuntos
Envelhecimento/imunologia , Células Estromais/patologia , Linfócitos T/imunologia , Timo/patologia , Animais , Atrofia , Humanos , CamundongosRESUMO
Although autoimmune disorders are a significant source of morbidity and mortality in older individuals, the mechanisms governing age-associated increases in susceptibility remain incompletely understood. Central T cell tolerance is mediated through presentation of self-antigens by cells constituting the thymic microenvironment, including epithelial cells, dendritic cells, and B cells. Medullary thymic epithelial cells (mTECs) and B cells express distinct cohorts of self-antigens, including tissue-restricted self-antigens (TRAs), such that developing T cells are tolerized to antigens from peripheral tissues. We find that expression of the TRA transcriptional regulator Aire, as well as Aire-dependent genes, declines with age in thymic B cells in mice and humans and that cell-intrinsic and cell-extrinsic mechanisms contribute to the diminished capacity of peripheral B cells to express Aire within the thymus. Our findings indicate that aging may diminish the ability of thymic B cells to tolerize T cells, revealing a potential mechanistic link between aging and autoimmunity.
Assuntos
Envelhecimento/imunologia , Autoantígenos/biossíntese , Linfócitos B/imunologia , Tolerância Central/imunologia , Timo/imunologia , Fatores de Transcrição/biossíntese , Adulto , Envelhecimento/patologia , Animais , Linfócitos B/metabolismo , Pré-Escolar , Humanos , Lactente , Camundongos , Pessoa de Meia-Idade , Timo/metabolismo , Proteína AIRERESUMO
BACKGROUND: Glass ionomer cements (GICs) are widely used in dentistry because of their remineralizing and cariostatic potential induced by fluoride. In vitro studies have reported cell toxicity triggered by GICs; however, the influence of hydroxyapatite (HAp) must be considered. The aim of this study was to evaluate the effect of HAp in decreasing the cytotoxicity of the GIC 3M Vitrebond in vitro. METHODS: Samples of 3M Vitrebond (powder, liquid and light-cured) were incubated in Dulbecco's modified Eagle's medium-Ham's F12 (DMEM-F12) for 24 hours at 37°C. Subsequently, the light-cured medium was treated with 100 mg/mL of HAp overnight. Toxicity of conditioned media diluted 1:2, 1:4, 1:8 and 1:20 was analyzed on human gingival fibroblasts (HGFs) using light microscopy and the fluorometric microculture cytotoxicity assay. The amounts of calcium fluoride (CaF2) were determined by the alizarin red S method. RESULTS: The exposure of HGFs to light-cured induced cell death and morphological changes such as chromatin condensation, pyknotic nuclei and cytoplasmic modifications. Exposure to light-cured treated with HAp, significantly increased cell viability leading to mostly spindle-shaped cells (p<0.001). The concentration of CaF2 released by the light-cured was 200 ppm, although, in the light-cured/HAp conditioned medium, this quantity decreased to 88 ppm (p<0.01). CONCLUSIONS: These data suggest that HAp plays a protective role, decreasing the cytotoxic effect of 3M Vitrebond induced by CaF2.
Assuntos
Fluoreto de Cálcio , Durapatita , Cimentos de Ionômeros de Vidro , Fluoreto de Cálcio/química , Fluoreto de Cálcio/farmacocinética , Fluoreto de Cálcio/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular , Durapatita/química , Durapatita/farmacocinética , Durapatita/farmacologia , Cimentos de Ionômeros de Vidro/efeitos adversos , Cimentos de Ionômeros de Vidro/farmacocinética , Cimentos de Ionômeros de Vidro/farmacologia , HumanosRESUMO
AIM: The objective of this study was to evaluate the antitumor activity of lipophilic bismuth nanoparticles (BisBAL NPs) on breast cancer cells. MATERIALS AND METHODS: The effect of varying concentrations of BisBAL NPs was evaluated on human MCF-7 breast cancer cells and on MCF-10A fibrocystic mammary epitheliocytes as noncancer control cells. Cell viability was evaluated with the MTT assay, plasma membrane integrity was analyzed with the calcein AM assay, genotoxicity with the comet assay, and apoptosis with the Annexin V/7-AAD assay. RESULTS: BisBAL NPs were spherical in shape (average diameter, 28 nm) and agglomerated into dense electronic clusters. BisBAL NP induced a dose-dependent growth inhibition. Most importantly, growth inhibition was higher for MCF-7 cells than for MCF-10A cells. At 1 µM BisBAL NP, MCF-7 growth inhibition was 51%, while it was 11% for MCF-10A; at 25 µM BisBAL NP, the growth inhibition was 81% for MCF-7 and 24% for MCF-10A. With respect to mechanisms of action, a 24-hour exposure of 10 and 100 µM BisBAL NP caused loss of cell membrane integrity and fragmentation of tumor cell DNA. BisBAL NPs at 10 µM were genotoxic to and caused apoptosis of breast cancer cells. CONCLUSION: BisBAL NP-induced growth inhibition is dose dependent, and breast cancer cells are more vulnerable than noncancer breast cells. The mechanism of action of BisBAL NPs may include loss of plasma membrane integrity and a genotoxic effect on the genomic DNA of breast cancer cells.
Assuntos
Antineoplásicos/farmacologia , Bismuto/farmacologia , Neoplasias da Mama/patologia , Dimercaprol/análogos & derivados , Nanopartículas/química , Compostos Organometálicos/farmacologia , Apoptose/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Dano ao DNA , Dimercaprol/farmacologia , Feminino , Humanos , Células MCF-7 , Nanopartículas/ultraestruturaRESUMO
La instrumentación mecánica durante el tratamiento periodontal trae consigo la formación de escombros microcristalinos que inhiben la adhesión tisular a la superfi cie radicular y favorece la proliferación bacteriana, lo cual perjudica los resultados del tratamiento periodontal a corto y largo plazo. Hoy en día el acondicionamiento radicular con el uso de biomodifi cadores es una opción de tratamiento adicional en el tratamiento de la periodontitis y el tratamiento de cobertura radicular. El objetivo del presente estudio es realizar una revisión de la literatura acerca de las aplicaciones y del acondicionamiento radicular con ácido cítrico, tetraciclina, EDTA y láser en el tratamiento periodontal no quirúrgico y quirúrgico (AU)
Mechanical instrumentation during periodontal treatment brings the formation of microcrystalline debris that inhibits tissue adhesion to the root surface and favors bacterial proliferation, which harms the results of the short and long term periodontal treatment. Nowadays, root conditioning with the use of biomodifi cators is an additional treatment option in the treatment of periodontitis and root coverage therapy. The aim of the present study is to conduct a literature review about the applications and the root conditioning with citric acid, tetracycline, EDTA and laser in the non surgical and surgical periodontal treatment (AU)
Assuntos
Humanos , Doenças Periodontais/cirurgia , Doenças Periodontais/terapia , Raiz Dentária/efeitos dos fármacos , Tetraciclinas , Raspagem Dentária , Aplainamento Radicular , Ácido Edético , Ácido Cítrico , Terapia a LaserRESUMO
Este estudio contempla el análisis y comparación del sellado intracoronal en 50 órganos dentarios unirradiculares humanos extraídos, a los que se les realizó tratamiento endodóntico; posteriormente se dividieron en 5 grupos, de 10 cada uno, aplicando en 4 de los grupos los materiales utilizados como método barrera: Cavit G, Ketac Molar, Perma Seal, Single Bond y 1 grupo aparte de control que fue conformado sin ningún tipo de material de barrera. Luego fueron sumergidos en saliva artificial durante 1 mes; transcurrido este tiempo fueron teñidos con azul de metileno al 2% y se procedió a realizar los cortes para su estudio, evaluando la filtración corono apical en 7 secciones de 1mm cada una en toda la longitud radicular, inmediatamente después del material utilizado como método de barrera. Resultados: Se encontró que el adhesivo Single Bond fue el más eficaz como material barrera y que evitó la filtración corono apical.
This study analizes and compares the intracoronal sealing of 50 extracted, single rooted, human dental organs that underwent endodontic treatment; they were divided in 5 groups of 10 each, applying the materials used as barrier method: Cavit G, Ketac Molar, Perma Seal, Single Bond and to 4 groups and leaving one control group without any barrier material. Afterwards they were submerged in artificial saliva for 1 month; after this time they were stained with methylene blue at 2% and proceeded to make the cuts for their study, evaluating crown-apical filtration in 7 sections of 1 mm each along the entire root length starting immediately after the material used as a barrier method. Results: found that the adhesive Single Bond was the most effective as material barrier to avoid crown-apical filtration
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Despite being a commonly studied topic, it is difficult to find studies which explain the problem of dental erosion. For this article, literature was analyzed to find information on the agents which trigger dental erosion, the main diagnosis methods, the most common treatments used nowadays and the interrelationship with dental materials. The etiology of dental erosion is multifactorial, including acids, eating disorders and gastro-esophageal reflux. However, biological factors such as saliva or habits also play a part in the establishment of this condition. In order to establish a reliable diagnosis, clinical appearance becomes decisive. The Basic Index Erosive Wear Exami¬nation (BEWE), created in 2008, is an auxiliary diagnosis tool for assessing the status and progress of the erosion. Treatment should be linked to the eradication of the causative agent and it can range from simple observational monitoring of slightly affected teeth to the placement of total crowns in the most severe cases, but this will depend entirely on the extent, severity, symptoms and type of dentition. Regarding dental materials used in the treatment of eroded parts, there are glass ionomer and composite; the latter presents the greatest resistance to biodegradation when interacting with acids. Glass ionomers are the most vulnerable material while resin is seen as the most resistant. In conclusion, dental erosion has become an issue of great importance in the dental practice because of its serious impact on dental structures. Consequently, it is ranked among the most important dental disorders in the present day.
A pesar de ser un tópico altamente examinado, es difícil encontrar estudios que esclarezcan la problemática de la erosión dental. En este trabajo se analizó en la literatura los agentes que desencadenan la erosión dental, los principales métodos de diagnosis, los tratamientos más empleados en la actualidad y la interrelación con los materiales dentales. La etiología de la erosión es multifactorial incluyendo elementos ácidos, desórdenes alimenticios y reflujo gastroesofágico. Sin embargo, los factores biológicos como la saliva o los hábitos también intervienen en el establecimiento de la afección. Para establecer un diagnóstico fiable, la apariencia clínica se vuelve decisiva. Un auxiliar diagnóstico para evaluar el estado y progreso de la erosión es el índice Basic Erosive Wear Examination (BEWE) establecido en el 2008. La terapéutica deberá estar ligada a la erradicación del agente causal y consistirá desde simple observación hasta coronas totales en los casos más severos, pero esta dependerá totalmente de la extensión, severidad, sintomatología y tipo de dentición presente. Dentro de los materiales dentales empleados en el tratamiento de piezas erosionadas, se encuentran el ionómero de vidrio y el composite; siendo este último quien presenta mayor resistencia a la biodegradación al interactuar con elementos ácidos. El ionómero de vidrio constituye el material más vulnerable mientras que la resina se posiciona como la más resisten¬te. La erosión dental se ha vuelto una cuestión de gran importancia en el ámbito odontológico por las graves re¬percusiones que se producen en las estructuras dentales, posicionándola como uno de los desordenes dentales con mayor trascendencia en la actualidad.