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1.
J Dent ; 94: 103297, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32057768

RESUMO

OBJECTIVES: The role played by macrophages in regulating the differentiation of mesenchymal stem cells (MSCs) during wound healing and bone regeneration is increasingly being recognized. The present study compared the pro-osteogenic effects of three co-culture methods, conditioned medium generated by macrophages (CM), indirect culture (IC) or direct culture (DC) with macrophages, on bone marrow MSCs (BMMSCs). METHODS: Primary BMMSCs were isolated, characterized and co-cultured with RAW264.7 mouse macrophages. Cell morphology and intracellular reactive oxygen species (ROS) levels were determined by scanning electron microscopy (SEM) and flow cytometry, respectively. Alkaline phosphatase (ALP) staining and assay, Alizarin red staining (ARS) and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to evaluate osteogenic differentiation. RESULTS: Inclusion of macrophages in any of the three co-culture methods resulted in improvement in osteogenic differentiation and mineralization of BMMSCs (DC > IC > CM), as measured by ALP staining and activity, ARS and osteoblastic gene expression (Runx2, Alp, Ocn and Bmp2). The enhanced osteogenesis was reversed with hydrogen peroxide. Macrophages reduced the increased levels of intracellular ROS generated by BMMSCs during osteogenic differentiation in a manner similar to the use of an antioxidant, N-acetyl cysteine. CONCLUSIONS: Macrophages exert an osteogenesis-enhancing effect to accelerate BMMSC osteogenesis via ROS downregulation. CLINICAL SIGNIFICANCE: The present findings suggest that targeting MSC-macrophage interaction is an effective strategy for regulating stem cell fate and facilitating bone regeneration.

2.
Nutrients ; 12(2)2020 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-31991934

RESUMO

This study aimed to investigate the effect of sesamol (SEM) on the protein kinase A (PKA) pathway in obesity-related hepatic steatosis treatment by using high-fat diet (HFD)-induced obese mice and a palmitic acid (PA)-treated HepG2 cell line. SEM reduced the body weight gain of obese mice and alleviated related metabolic disorders such as insulin resistance, hyperlipidemia, and systemic inflammation. Furthermore, lipid accumulation in the liver and HepG2 cells was reduced by SEM. SEM downregulated the gene and protein levels of lipogenic regulator factors, and upregulated the gene and protein levels of the regulator factors responsible for lipolysis and fatty acid ß-oxidation. Meanwhile, SEM activated AMP-activated protein kinase (AMPK), which might explain the regulatory effect of SEM on fatty acid ß-oxidation and lipogenesis. Additionally, the PKA-C and phospho-PKA substrate levels were higher after SEM treatment. Further research found that after pretreatment with the PKA inhibitor, H89, lipid accumulation was increased even with SEM administration in HepG2 cells, and the effect of SEM on lipid metabolism-related regulator factors was abolished by H89. In conclusion, SEM has a positive therapeutic effect on obesity and obesity-related hepatic steatosis by regulating the hepatic lipid metabolism mediated by the PKA pathway.

3.
Int J Oral Sci ; 11(3): 28, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31570700

RESUMO

Effective control of oral biofilm infectious diseases represents a major global challenge. Microorganisms in biofilms exhibit increased drug tolerance compared with planktonic cells. The present review covers innovative antimicrobial strategies for controlling oral biofilm-related infections published predominantly over the past 5 years. Antimicrobial dental materials based on antimicrobial agent release, contact-killing and multi-functional strategies have been designed and synthesized for the prevention of initial bacterial attachment and subsequent biofilm formation on the tooth and material surface. Among the therapeutic approaches for managing biofilms in clinical practice, antimicrobial photodynamic therapy has emerged as an alternative to antimicrobial regimes and mechanical removal of biofilms, and cold atmospheric plasma shows significant advantages over conventional antimicrobial approaches. Nevertheless, more preclinical studies and appropriately designed and well-structured multi-center clinical trials are critically needed to obtain reliable comparative data. The acquired information will be helpful in identifying the most effective antibacterial solutions and the most optimal circumstances to utilize these strategies.


Assuntos
Antibacterianos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Biofilmes/efeitos dos fármacos , Boca/microbiologia , Antibacterianos/uso terapêutico , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Humanos , Plâncton
4.
J Clin Neurosci ; 65: 125-133, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31036506

RESUMO

The present study focused on the novel roles and the underlying mechanisms of miR-135b in pyroptosis of MPP+-induced Parkinson's disease (PD). We established an in vitro PD model induced by MPP+. Our results demonstrated miR-135b was lower while FoxO1 was inversely higher in MPP+-treated SH-SY5Y and PC-12 cells. Luciferase reporter assay showed FoxO1 was a downstream target of miR-135b. MiR-135b mimics suppressed MPP+-induced pyroptosis and the upregulation of TXNIP, NLRP3, Caspase-1, ASC, GSDMDNterm and IL-1ß. Moreover, FoxO1 overexpression had no effect on miR-135b but reversed its own downregulation caused by miR-135b mimics. Meanwhile, overexpression of FoxO1 abolished the inhibitory effects of miR-135b on pyroptosis and reversed the downregulation of pyroptotic genes and LDH release. In summary, miR-135b played a protective role in Parkinson's disease via inhibiting pyroptosis by targeting FoxO1. MiR-135b might serve as a potential therapeutic target in the treatment of Parkinson's disease.


Assuntos
Proteína Forkhead Box O1/metabolismo , Inflamassomos/metabolismo , MicroRNAs/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Doença de Parkinson/genética , Piroptose/genética , Proteínas de Transporte/metabolismo , Humanos , Proteínas de Neoplasias/genética , Regulação para Cima
5.
Oxid Med Cell Longev ; 2019: 3501059, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31089407

RESUMO

Dental resin monomers such as 2-hydroxyethyl methacrylate (HEMA) disturb vital cell functions and induce mitochondrial intrinsic apoptosis via generation of oxidative stress. Nuclear factor erythroid 2-related factor 2 (Nrf2) regulates the gene expression of antioxidative enzymes and plays a crucial role in the maintenance of cellular redox equilibrium and mitochondrial homeostasis. The present study investigated the functional significance of Nrf2 in cellular response toward HEMA. It was found that HEMA stimulation promoted nuclear translocation of Nrf2 and increased Nrf2 and heme oxygenase-1 (HO-1) expression, which was further enhanced by Nrf2 activator tert-butylhydroquinone (tBHQ), but suppressed by Nrf2 inhibitor ML385. Pretreatment of primary human dental pulp cells (hDPCs) with tBHQ protected the cells from HEMA-induced oxidative injury (increased reactive oxygen species production and apoptosis) and mitochondrial impairment (morphological alterations, decreased ATP production, suppressed oxidative phosphorylation activity, depolarization of mitochondrial membrane potential, and disrupted electron transport chain). In contrast, pretreatment with ML385 increased cell sensitivity to these injurious processes. This protective effect on mitochondria could be related to peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α)/nuclear respiratory factor 1 (NRF1) pathway. These results contribute to the understanding of the function of Nrf2 and the development of novel therapies to counteract the adverse effects of dental resin monomers.


Assuntos
Metacrilatos/toxicidade , Mitocôndrias/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Substâncias Protetoras/metabolismo , Adolescente , Adulto , Apoptose/efeitos dos fármacos , Polpa Dentária/patologia , Polpa Dentária/ultraestrutura , Heme Oxigenase-1/metabolismo , Humanos , Hidroquinonas/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Modelos Biológicos , Fator 1 Nuclear Respiratório/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Adulto Jovem
6.
Acta Biomater ; 90: 424-440, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30953801

RESUMO

During development of mineralized collagenous tissues, intrafibrillar mineralization is achieved by preventing mineralization precursor inhibitors that are larger than 40 kDa from entering the collagen fibrils. Such a property is incorporated in the design of a calcium chelator for dentin bonding in the etch-and-rinse technique that selectively demineralizes extrafibrillar apatite while leaving the intrafibrillar minerals intact. This strategy prevents complete demineralization of collagen fibrils, avoids collapse of collagen that blocks resin infiltration after air-drying, and protects the completely demineralized fibrils from bacteria colonization and degradation by endogenous proteases after resin bonding. In the present study, a water-soluble glycol chitosan-EDTA (GCE) conditioner was synthesized by conjugation of EDTA, an effective calcium chelator, to high molecular weight glycol chitosan, which exhibits weak chelation property. The GCE conjugate was purified, characterized by FTIR, 1H NMR, isothermal titration calorimetry and ICP-AES, and subjected to size exclusion dialysis to recover molecules that are >40 kDa. The optimal concentration and application time for etching dentin were determined by bond strength testing to ensure that the dentin bonding results were comparable to phosphoric acid etching, and maintained equivalent bond strength after air-drying of the conditioned collagen matrix. Extrafibrillar demineralization was validated with transmission electron microscopy. Inhibition of endogenous dentin proteases was confirmed using in-situ zymography. The water-soluble GCE dentin conditioner was non-cytotoxic and possessed antibacterial activities against planktonic and single-species biofilms, supporting its ongoing development as a dentin conditioner with air-drying, anti-proteolytic and antibacterial properties to enhance the durability of bonds created using the etch-and-rinse bonding technique. STATEMENT OF SIGNIFICANCE: The current state-of-the-art techniques for filling decayed teeth with plastic tooth-colored materials require conditioning the mineralized, biofilm-covered, decayed dentin with acids or acid resin monomers to create a surface layer of completely- or partially-demineralized collagen matrix for the infiltration of adhesive resin monomers. Nevertheless, fillings prepared using these strategies are not as durable as consumers have anticipated. Conjugation of polymeric glycol chitosan with EDTA produces a new conditioner for dentin bonding that demineralizes only extrafibrillar dentin, reduces endogenous protease activities and kills biofilm bacteria. The high molecular weight glycol chitosan-EDTA is non-cytotoxic to the key regenerative players within the dentin-pulp complex. This advance permits dry bonding and the use of hydrophobic resins.

7.
Adv Sci (Weinh) ; 5(10): 1800873, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30356983

RESUMO

Biomineralization in vertebrates is initiated via amorphous calcium phosphate (ACP) precursors. These precursors infiltrate the extracellular collagen matrix where they undergo phase transformation into intrafibrillar carbonated apatite. Although it is well established that ACP precursors are released from intracellular vesicles through exocytosis, an unsolved enigma in this cell-mediated mineralization process is how ACP precursors, initially produced in the mitochondria, are translocated to the intracellular vesicles. The present study proposes that mitophagy provides the mechanism for transfer of ACP precursors from the dysfunctioned mitochondria to autophagosomes, which, upon fusion with lysosomes, become autolysosomes where the mitochondrial ACP precursors coalesce to form larger intravesicular granules, prior to their release into the extracellular matrix. Apart from endowing the mitochondria with the function of ACP delivery through mitophagy, the present results indicate that mitophagy, triggered upon intramitochondrial ACP accumulation in osteogenic lineage-committed mesenchymal stem cells, participates in the biomineralization process through the BMP/Smad signaling pathway.

8.
J Dent ; 72: 53-63, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29534887

RESUMO

OBJECTIVES: To evaluate the bonding performance, antibacterial activity, and remineralization effect on enamel of the orthodontic adhesive containing MAE-DB and NACP. METHODS: Eighty non-carious human premolars were divided into 3 groups: Transbond XT (TB), PEHB + 5% MAE-DB (PD), and PEHB + 40% NACP + 5% MAE-DB (PND). Premolars were bonded with orthodontic brackets, the first subgroup (n = 10) and the second subgroup (n = 10) were subjected to shear bond strength testing after immersed in water for 1 day and in demineralization solution for 28 days respectively and then tested surface roughness, while the third subgroup (n = 6) was used for microhardness evaluation after aged in demineralization solution for 28 days. For each adhesive, fifty disk samples were prepared for antibacterial study. Specimens measuring 12 mm × 2 mm × 2 mm were fabricated for ion release test. RESULTS: Bond strengths were in the order TB = PND > PND = PD for "1-day in water", and in the order TB = PND > PD for "28-days in pH 4 solution". No significant difference in the ARI scores for the three adhesive. Numerous bacteria adhered to TB surface, while PD and PND had minimal bacterial growth and activity. PND showed high levels of Ca and P ions release and enamel hardness. The surface roughness of enamel in PND was much lower than TB and PD and showed no significant difference with the sound, control enamel. CONCLUSION: PND adhesive with 5% MAE-DB and 40% NACP exhibits antibacterial and remineralizing capabilities, and did not adversely affect bond strength compared to commercial adhesive. CLINICAL SIGNIFICANCE: Novel adhesive containing quaternary ammonium monomer and nano-amorphous calcium phosphate represents a promising candidate in combating enamel white spot lesions and even dental caries.


Assuntos
Compostos de Amônio/química , Antibacterianos/química , Fosfatos de Cálcio/química , Cimentos Dentários/química , Nanopartículas/química , Remineralização Dentária , Adesinas Bacterianas/efeitos dos fármacos , Antibacterianos/farmacologia , Dente Pré-Molar , Biofilmes/efeitos dos fármacos , Colagem Dentária , Cárie Dentária/prevenção & controle , Cimentos Dentários/farmacologia , Esmalte Dentário , Combinação de Medicamentos , Dureza/efeitos dos fármacos , Humanos , Teste de Materiais , Metacrilatos/química , Braquetes Ortodônticos , Cimentos de Resina , Resistência ao Cisalhamento , Propriedades de Superfície
9.
Acta Biomater ; 67: 354-365, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29274477

RESUMO

Intrafibrillar silicified collagen scaffold (SCS) is a promising biomaterial for bone regeneration because it promotes cell homing and angiogenesis in bone defects via monocyte modulation. In the present study, a rat femoral defect model was used to examine the contribution of monocyte signaling pathways to SCS modulation. Activation of the monocyte p38 signaling pathway by SCS resulted in monocyte differentiation into TRAP-positive mononuclear cells. These cells demonstrated increased secretion of SDF-1α, VEGFa and PDGF-BB, which, in turn, promoted homing of bone marrow stromal cells (BMSCs) and endothelial progenitor cells (EPCs), as well as local vascularization. Monocyte differentiation and secretion were blocked after inhibition of the p38 pathway, which resulted in reduction in cell homing and angiogenesis. Taken together, these novel findings indicate that the p38 signaling pathway is crucial in SCS-modulated monocyte differentiation and secretion, which has a direct impact on SCS-induced bone regeneration. STATEMENT OF SIGNIFICANCE: Intrafibrillar silicified collagen scaffold (SCS) is a promising biomaterial for bone regeneration. The present work demonstrates that SCS possesses favorable bone regeneration potential in a rat femoral defect model. The degrading scaffold modulates monocyte differentiation and release of certain cytokines to recruit MSCs and EPCs, as well as enhances local vascularization by activating the p38 MAPK signaling pathway. These findings indicate that SCS contributes to bone defect regeneration by stimulating host cell homing and promoting local angiogenesis and osteogenesis without the need for loading cytokines or xenogenous stem cells.


Assuntos
Regeneração Óssea/fisiologia , Colágenos Fibrilares/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Monócitos/enzimologia , Dióxido de Silício/química , Tecidos Suporte/química , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Regeneração Óssea/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fêmur/patologia , Masculino , Camundongos Endogâmicos C57BL , Monócitos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
10.
Materials (Basel) ; 10(2)2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28772546

RESUMO

This study evaluated epigallocatechin-3-gallate (EGCG) and epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG-3Me) modified etch-and-rinse adhesives (Single Bond 2, SB 2) for their antibacterial effect and bonding stability to dentin. EGCG-3Me was isolated and purified with column chromatography and preparative high performance liquid chromatography. EGCG and EGCG-3Me were incorporated separately into the adhesive SB 2 at concentrations of 200, 400, and 600 µg/mL. The effect of cured adhesives on the growth of Streptococcus mutans (S. mutans) was determined with scanning electron microscopy and confocal laser scanning microscopy; the biofilm of bacteria was further quantified via optical density 600 values. The inhibition of EGCG and EGCG-3Me on dentin-originated collagen proteases activities was evaluated with a proteases fluorometric assay kit. The degree of conversion (DC) of the adhesives was tested with micro-Raman spectrum. The immediate and post-thermocycling (5000 cycles) bond strength was assessed through Microtensile Bond Strength (MTBS) test. Cured EGCG/EGCG-3Me modified adhesives inhibit the growth of S. mutans in a concentration-dependent manner. The immediate MTBS of SB 2 was not compromised by EGCG/EGCG-3Me modification. EGCG/EGCG-3Me modified adhesive had higher MTBS than SB 2 after thermocycling, showing no correlation with concentration. The DC of the adhesive system was affected depending on the concentration of EGCG/EGCG-3Me and the depth of the hybrid layer. EGCG/EGCG-3Me modified adhesives could inhibit S. mutans adhesion to dentin-resin interface, and maintain the bonding stability. The adhesive modified with 400 µg/mL EGCG-3Me showed antibacterial effect and enhanced bonding stability without affect the DC of adhesive.

11.
Sci Rep ; 7(1): 4235, 2017 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-28652570

RESUMO

This study was to evaluate the effect of Epigallocatechin-3-gallate (EGCG) on the bond strength of two adhesive systems to the Sodium hypochlorite (NaOCl) treated intraradicular dentin. The roots were accepted regular root canal treatments and post space preparations, and further divided into eight groups according to the four post space pretreatments and two dentin adhesives [Single Bond 2 (SB2) and Clearfil SE Bond (CSB)] used. The push-out strength before and after thermocycling in different root region (coronal and apical), DC of the adhesive and morphologic patterns of treated post space were evaluated. NaOCl + EGCG groups showed the highest push-out strength regardless of the adhesive type, root region and time (P < 0.05). NaOCl pretreatment significantly decreased the push-out strengths and DC of CSB (P < 0.05). EGCG could improve the bonding properties of both SB2 and CSB to NaOCl treated intraradicular dentin. The effect of NaOCl on bonding of a fiber post depended on the type of the adhesive.


Assuntos
Catequina/análogos & derivados , Adesivos Dentinários/química , Dentina/efeitos dos fármacos , Materiais Restauradores do Canal Radicular/uso terapêutico , Catequina/química , Catequina/uso terapêutico , Cavidade Pulpar/efeitos dos fármacos , Dentina/química , Humanos , Cimentos de Resina/química , Cimentos de Resina/uso terapêutico , Materiais Restauradores do Canal Radicular/química , Irrigantes do Canal Radicular/química , Hipoclorito de Sódio/química , Hipoclorito de Sódio/uso terapêutico
12.
Acta Biomater ; 57: 435-448, 2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28499631

RESUMO

Limitations associated with wet-bonding led to the recent development of a selective demineralization strategy in which dentin was etched with a reduced concentration of phosphoric acid to create exclusive extrafibrillar demineralization of the collagen matrix. However, the use of acidic conditioners removes calcium via diffusion of very small hydronium ions into the intrafibrillar collagen water compartments. This defeats the purpose of limiting the conditioner to the extrafibrillar space to create a collagen matrix containing only intrafibrillar minerals to prevent collapse of the collagen matrix. The present work examined the use of polymeric chelators (the sodium salt of polyacrylic acid) of different molecular weights to selectively demineralize extrafibrillar dentin. These polymeric chelators exhibit different affinities for calcium ions (isothermal titration calorimetry), penetrated intrafibrillar dentin collagen to different extents based on their molecular sizes (modified size-exclusion chromatography), and preserve the dynamic mechanical properties of mineralized dentin more favorably compared with completely demineralized phosphoric acid-etched dentin (nanoscopical dynamic mechanical analysis). Scanning and transmission electron microscopy provided evidence for retention of intrafibrillar minerals in dentin surfaces conditioned with polymeric chelators. Microtensile bond strengths to wet-bonded and dry-bonded dentin conditioned with these polymeric chelators showed that the use of sodium salts of polyacrylic acid for chelating dentin prior to bonding did not result in significant decline in resin-dentin bond strength. Taken together, the findings led to the conclusion that a chelate-and-rinse conditioning technique based on extrafibrillar collagen demineralization bridges the gap between wet and dry dentin bonding. STATEMENT OF SIGNIFICANCE: The chelate-and-rinse dental adhesive bonding concept differentiates from previous research in that it is based on the size-exclusion characteristics of fibrillar collagen; molecules larger than 40kDa are prevented from accessing the intrafibrillar water compartments of the collagen fibrils. Using this chelate-and-rinse extrafibrillar calcium chelation concept, collagen fibrils with retained intrafibrillar minerals will not collapse upon air-drying. This enables adhesive infiltration into the mineral-depleted extrafibrillar spaces without relying on wet-bonding. By bridging the gap between wet and dry dentine bonding, the chelate-and-rinse concept introduces additional insight to the field by preventing exposure of endogenous proteases via preservation of the intrafibrillar minerals within a collagen matrix. If successfully validated, this should help prevent degradation of resin-dentine bonds by collagenolytic enzymes.


Assuntos
Colágeno/química , Dentina/química , Dente Molar/química , Desmineralização do Dente , Humanos
13.
Sci Rep ; 7(1): 388, 2017 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-28341838

RESUMO

Although it is believed that implementation of the functional generated path (FGP) technique can facilitate occlusal surface design for restorations, it has not been objectively compared in situ with the conventional fabrication yet. Therefore, in the present study, a single-blind crossover clinical trial was conducted using T-scan to compare changes in occlusion time (OT) and disocclusion time (DT) of single posterior artificial crowns designed differently using FGP technique (FGP), average-value FGP technique (AVR) and conventional fabrication (CON). Each of the 10 participants took part in the study tried three artificial crowns in different sequences according to a computer generated randomization list. The results objectively revealed that changes in OT and DT were significantly smaller for FGP than CON (P < 0.05) and considerably smaller for AVR than CON, respectively. The subjective feedback and the occlusal adjusting time were better and shorter for FGP and AVR than CON (P < 0.05). No harm to the participants occurred. Overall, FGP is an efficient technique showing more physiological harmonious relationship with the articulating system.


Assuntos
Coroas , Oclusão Dentária , Restauração Dentária Permanente/métodos , Adulto , Idoso , Projeto Auxiliado por Computador , Estudos Cross-Over , Feminino , Humanos , Masculino , Teste de Materiais , Pessoa de Meia-Idade , Método Simples-Cego , Adulto Jovem
14.
Sci Rep ; 7: 41787, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28169312

RESUMO

Irreversible white spot lesion (WSL) occurs in up to 50% of patients during orthodontic treatment. Therefore, orthodontic adhesives need to be able to inhibit or reduce bacterial growth in order to prevent or minimize WSL. This study evaluated the antibacterial effect and shear bond strength (SBS) of a resin-based orthodontic adhesive containing the antibacterial monomer 2-methacryloxylethyl hexadecyl methyl ammonium bromide (MAE-HB). MAE-HB was added at three concentrations (1, 3, and 5 wt%) to a commercial orthodontic adhesive Transbond XT, while the blank control comprised unmodified Transbond XT. Their antibacterial effects on Streptococcus mutans were investigated after 0 and 180 days of aging. The SBS of metal brackets bonded to the buccal enamel surface of human premolars was assessed. Compared with the blank control, the MAE-HB-incorporated adhesive exhibited a significant contact inhibitory effect on the growth of S. mutans (P < 0.05), even after 180 days of aging. SBS and adhesive remnant index values revealed that the bonding ability of the experimental adhesive was not significantly adversely affected by the incorporation of MAE-HB at any of the three concentrations. Therefore, orthodontic adhesives with strong and long-lasting bacteriostatic properties can be created through the incorporation of MAE-HB without negatively influencing bonding ability.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Metacrilatos/química , Metacrilatos/farmacologia , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologia , Biofilmes/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Resistência ao Cisalhamento , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/ultraestrutura
16.
Nat Mater ; 16(3): 370-378, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27820813

RESUMO

Mineralization of fibrillar collagen with biomimetic process-directing agents has enabled scientists to gain insight into the potential mechanisms involved in intrafibrillar mineralization. Here, by using polycation- and polyanion-directed intrafibrillar mineralization, we challenge the popular paradigm that electrostatic attraction is solely responsible for polyelectrolyte-directed intrafibrillar mineralization. As there is no difference when a polycationic or a polyanionic electrolyte is used to direct collagen mineralization, we argue that additional types of long-range non-electrostatic interaction are responsible for intrafibrillar mineralization. Molecular dynamics simulations of collagen structures in the presence of extrafibrillar polyelectrolytes show that the outward movement of ions and intrafibrillar water through the collagen surface occurs irrespective of the charges of polyelectrolytes, resulting in the experimentally verifiable contraction of the collagen structures. The need to balance electroneutrality and osmotic equilibrium simultaneously to establish Gibbs-Donnan equilibrium in a polyelectrolyte-directed mineralization system establishes a new model for collagen intrafibrillar mineralization that supplements existing collagen mineralization mechanisms.


Assuntos
Colágenos Fibrilares/química , Colágenos Fibrilares/ultraestrutura , Minerais/química , Simulação de Dinâmica Molecular , Pressão Osmótica , Eletricidade Estática , Simulação por Computador , Eletrólitos/química
17.
Biomaterials ; 113: 203-216, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27821306

RESUMO

The immunomodulatory functions of monocytes are increasingly being recognized. Silicified collagen scaffolds (SCSs), produced by infiltrating collagen matrices with intrafibrillar amorphous silica, exhibit osteogenic and angiogenic potential and are promising candidates in tissue engineering. Here, we demonstrate that SCS promotes in situ bone regeneration and angiogenesis via monocyte immunomodulation. Increased numbers of TRAP-positive monocytes, nestin-positive bone marrow stromal cells (BMSCs) and CD31-positive and endomucin-positive new vessels can be identified from new bone formation regions in a murine calvarial defect model. In addition, sustained release of silicic acid by SCS stimulates differentiation of blood-derived monocytes into TRAP-positive cells, with increased expressions of SDF-1α, TGF-ß1, VEGFa and PDGF-BB. These cytokines further promote homing of BMSCs and endothelial progenitor cells as well as neovascularization. Taken together, these novel findings indicate that SCSs possess the ability to enhance recruitment of progenitor cells and promote osteogenesis and angiogenesis by immunomodulation of monocytes.


Assuntos
Regeneração Óssea , Colágeno/química , Monócitos/citologia , Neovascularização Fisiológica , Ácido Silícico/química , Crânio/fisiologia , Tecidos Suporte/química , Animais , Células Cultivadas , Quimiotaxia , Colágeno/imunologia , Imunomodulação , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/imunologia , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Ácido Silícico/imunologia , Crânio/irrigação sanguínea , Crânio/imunologia , Crânio/lesões
18.
Sci Rep ; 6: 34713, 2016 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-27698421

RESUMO

Effective pulp-capping materials must have antibacterial properties and induce dentin bridge formation; however, many current materials do not satisfy clinical requirements. Accordingly, the effects of an experiment pulp-capping material (Exp) composed of an antibacterial resin monomer (MAE-DB) and Portland cement (PC) on the viability, adhesion, migration, and differentiation of human dental pulp stem cells (hDPSCs) were examined. Based on a Cell Counting Kit-8 assay, hDPSCs exposed to Exp extracts showed limited viability at 24 and 48 h, but displayed comparable viability to the control at 72 h. hDPSC treatment with Exp extracts enhanced cellular adhesion and migration according to in vitro scratch wound healing and Transwell migration assays. Exp significantly upregulated the expression of osteogenesis-related genes. The hDPSCs cultured with Exp exhibited higher ALP activity and calcium deposition in vitro compared with the control group. The novel material showed comparable cytocompatibility to control cells and promoted the adhesion, migration, and osteogenic differentiation of hDPSCs, indicating excellent biocompatibility. This new direct pulp-capping material containing MAE-DB and PC shows promise as a potential alternative to conventional materials for direct pulp capping.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Cimentos Dentários/farmacologia , Polpa Dentária/efeitos dos fármacos , Metacrilatos/farmacologia , Osteogênese/efeitos dos fármacos , Compostos de Amônio Quaternário/farmacologia , Células-Tronco/efeitos dos fármacos , Adolescente , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Dente Pré-Molar/citologia , Dente Pré-Molar/cirurgia , Bioensaio , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Polpa Dentária/citologia , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Dente Molar/citologia , Dente Molar/cirurgia , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteocalcina/genética , Osteocalcina/metabolismo , Osteogênese/genética , Osteonectina/genética , Osteonectina/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Cultura Primária de Células , Sialoglicoproteínas/genética , Sialoglicoproteínas/metabolismo , Células-Tronco/citologia , Extração Dentária , Cicatrização/efeitos dos fármacos , Adulto Jovem
19.
Sci Rep ; 6: 33858, 2016 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-27659279

RESUMO

Resins with strong and long-lasting antibacterial properties are critical for the prevention of secondary dental caries. In this study, we evaluated the antibacterial effect and the underlying mechanism of action of an unfilled resin incorporating 2-methacryloxylethyl hexadecyl methyl ammonium bromide (MAE-HB) against Streptococcus mutans UA159 (S. mutans UA159). MAE-HB was added into unfilled resin at 10 mass%, and unfilled resin without MAE-HB served as the control. Bacterial growth was inhibited on 10%-MAE-HB unfilled resin compared with the control at 1 d, 7 d, 30 d, or 180 d (P < 0.05). The growth inhibitory effect was independent of the incubation time (P > 0.05). No significant differences in the antibacterial activities of eluents from control versus 10%-MAE-HB unfilled resins were observed at any time point (P > 0.05). The number of bacteria attached to 10%-MAE-HB unfilled resin was considerably lower than that to control. Fe-SEM and CLSM showed that 10%-MAE-HB unfilled resin disturbed the integrity of bacterial cells. Expression of the bacterial glucosyltransferases, gtfB and gtfC, was lower on 10%-MAE-HB unfilled resin compared to that on control (P < 0.05). These data indicate that incorporation of MAE-HB confers unfilled resin with strong and long-lasting antibacterial effects against S. mutans.

20.
Sci Rep ; 6: 32740, 2016 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-27599621

RESUMO

The present study examined the mechanism for caries resistance and the pulp responses in vital teeth following the use of the augmented-pressure adhesive displacement technique. Dentin adhesives were applied to the surface of sound dentin disks in 4 experimental groups: non-antibacterial adhesive and gentle adhesive displacement (N-G), non-antibacterial adhesive and augmented-pressure adhesive displacement (N-H), antibacterial adhesive and gentle adhesive displacement (A-G), antibacterial adhesive and augmented-pressure adhesive displacement (A-H). The depth of demineralization induced by biological or chemical demineralization models was measured using confocal laser scanning microscopy and analyzed with two-way ANOVA. Pulp responses of vital dog's teeth to the augmented-pressure adhesive displacement technique were evaluated using light microscopy. Depth of demineralization was significantly affected by "adhesive type" and "intensity of adhesive displacement" for biological demineralization. For chemical demineralization, only "intensity of adhesive displacement" showed significant influence on lesion depth. Pulp response of 0.1, 0.2 and 0.3 MPa groups showed only moderate disorganization of the odontoblast layer at 24 hours that completely re-organized after 3 weeks. Augmented-pressure adhesive displacement improves the caries resistance property of bonded dentin and does not cause irreversible pulpal damage to vital teeth when the air pressure employed is equal or smaller than 0.3 MPa.


Assuntos
Cárie Dentária/prevenção & controle , Adesivos Dentinários/uso terapêutico , Infecções Estreptocócicas/prevenção & controle , Animais , Polpa Dentária/efeitos dos fármacos , Adesivos Dentinários/farmacologia , Cães , Humanos , Masculino , Streptococcus mutans/efeitos dos fármacos
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