Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 127
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Development ; 148(2)2021 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-33323370

RESUMEN

The control of size and shape is an important part of regulatory process during organogenesis. Tooth formation is a highly complex process that fine-tunes the size and shape of the tooth, which are crucial for its physiological functions. Each tooth consists of a crown and one or more roots. Despite comprehensive knowledge of the mechanism that regulates early tooth crown development, we have limited understanding of the mechanism regulating root patterning and size during development. Here, we show that Ror2-mediated non-canonical Wnt signaling in the dental mesenchyme plays a crucial role in cell proliferation, and thereby regulates root development size in mouse molars. Furthermore, Cdc42 acts as a potential downstream mediator of Ror2 signaling in root formation. Importantly, activation of Cdc42 can restore cell proliferation and partially rescue the root development size defects in Ror2 mutant mice. Collectively, our findings provide novel insights into the function of Ror2-mediated non-canonical Wnt signaling in regulating tooth morphogenesis, and suggest potential avenues for dental tissue engineering.


Asunto(s)
Receptores Huérfanos Similares al Receptor Tirosina Quinasa/metabolismo , Raíz del Diente/embriología , Raíz del Diente/metabolismo , Vía de Señalización Wnt , Proteína de Unión al GTP cdc42/metabolismo , Animales , Diferenciación Celular , Proliferación Celular , Femenino , Masculino , Mesodermo/embriología , Ratones , Ratones Mutantes , Morfogénesis , Odontoblastos/citología , Odontoblastos/metabolismo , Raíz del Diente/citología
2.
Development ; 148(8)2021 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-33766930

RESUMEN

Stem cells self-renew or give rise to transit-amplifying cells (TACs) that differentiate into specific functional cell types. The fate determination of stem cells to TACs and their transition to fully differentiated progeny is precisely regulated to maintain tissue homeostasis. Arid1a, a core component of the switch/sucrose nonfermentable complex, performs epigenetic regulation of stage- and tissue-specific genes that is indispensable for stem cell homeostasis and differentiation. However, the functional mechanism of Arid1a in the fate commitment of mesenchymal stem cells (MSCs) and their progeny is not clear. Using the continuously growing adult mouse incisor model, we show that Arid1a maintains tissue homeostasis through limiting proliferation, promoting cell cycle exit and differentiation of TACs by inhibiting the Aurka-Cdk1 axis. Loss of Arid1a overactivates the Aurka-Cdk1 axis, leading to expansion of the mitotic TAC population but compromising their differentiation ability. Furthermore, the defective homeostasis after loss of Arid1a ultimately leads to reduction of the MSC population. These findings reveal the functional significance of Arid1a in regulating the fate of TACs and their interaction with MSCs to maintain tissue homeostasis.


Asunto(s)
Aurora Quinasa A/metabolismo , Proteína Quinasa CDC2/metabolismo , Proteínas de Unión al ADN/metabolismo , Incisivo/embriología , Células Madre Mesenquimatosas/metabolismo , Mitosis , Transducción de Señal , Factores de Transcripción/metabolismo , Animales , Aurora Quinasa A/genética , Proteína Quinasa CDC2/genética , Proteínas de Unión al ADN/genética , Ratones , Ratones Transgénicos , Factores de Transcripción/genética
3.
Nanotechnology ; 35(32)2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38688249

RESUMEN

Dealing with bone defects is a significant challenge to global health. Electrospinning in bone tissue engineering has emerged as a solution to this problem. In this study, we designed a PVDF-b-PTFE block copolymer by incorporating TFE, which induced a phase shift in PVDF fromαtoß, thereby enhancing the piezoelectric effect. Utilizing the electrospinning process, we not only converted the material into a film with a significant surface area and high porosity but also intensified the piezoelectric effect. Then we used polydopamine to immobilize BMP-2 onto PVDF-b-PTFE electrospun nanofibrous membranes, achieving a controlled release of BMP-2. The scaffold's characters were examined using SEM and XRD. To assess its osteogenic effectsin vitro, we monitored the proliferation of MC3T3-E1 cells on the fibers, conducted ARS staining, and measured the expression of osteogenic genes.In vivo, bone regeneration effects were analyzed through micro-CT scanning and HE staining. ELISA assays confirmed that the sustained release of BMP-2 can be maintained for at least 28 d. SEM images and CCK-8 results demonstrated enhanced cell viability and improved adhesion in the experimental group. Furthermore, the experimental group exhibited more calcium nodules and higher expression levels of osteogenic genes, including COL-I, OCN, and RUNX2. HE staining and micro-CT scans revealed enhanced bone tissue regeneration in the defective area of the PDB group. Through extensive experimentation, we evaluated the scaffold's effectiveness in augmenting osteoblast proliferation and differentiation. This study emphasized the potential of piezoelectric PVDF-b-PTFE nanofibrous membranes with controlled BMP-2 release as a promising approach for bone tissue engineering, providing a viable solution for addressing bone defects.


Asunto(s)
Proteína Morfogenética Ósea 2 , Regeneración Ósea , Indoles , Nanofibras , Osteogénesis , Polímeros , Ingeniería de Tejidos , Andamios del Tejido , Proteína Morfogenética Ósea 2/farmacología , Proteína Morfogenética Ósea 2/metabolismo , Nanofibras/química , Regeneración Ósea/efectos de los fármacos , Animales , Ratones , Indoles/química , Indoles/farmacología , Polímeros/química , Polímeros/farmacología , Ingeniería de Tejidos/métodos , Osteogénesis/efectos de los fármacos , Andamios del Tejido/química , Proliferación Celular/efectos de los fármacos , Línea Celular , Proteínas Inmovilizadas/farmacología , Proteínas Inmovilizadas/química , Supervivencia Celular/efectos de los fármacos
4.
J Craniofac Surg ; 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38771188

RESUMEN

The treatment of temporomandibular joint (TMJ) ankylosis in children is a great challenge for surgeons. Costochondral graft (CCG) is a common method of reconstructing the TMJ in children. However, the growth pattern of CCG is unpredictable. In this study, we introduced a surgical-orthodontic approach and evaluated the growth results of the mandible and maxilla in children with TMJ ankylosis through 3-dimensional computed tomography measurements. A prospective cohort study was conducted on child patients diagnosed as having TMJ ankylosis between September 1, 2018 and June 1, 2020. Computer-aided virtual mandibular position guided the CCG, and removable functional appliance was used after surgery. The maximal incisal opening (MIO), the maxilla height, and the length of mandibular ramus were determined. Paired t test was performed to analyze the differences among various stages. Six patients (3 females, 3 males; aged 6-9 y) were included in this study. MIO was 12.4 mm before surgery and improved to 36.8 mm after 42.8 months' follow-up. Mandible length increased by 5.1 mm in the affected side and by 5.3 mm in the unaffected side, without significant difference. The affected maxilla height increased by 6.7 mm, which was more than 5.0 mm in the unaffected side. In conclusion, continued growth of mandible and maxilla can be achieved through CCG combined with functional appliance treatment for children TMJ ankylosis.

5.
Soft Matter ; 19(35): 6754-6760, 2023 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-37641566

RESUMEN

Herein we report a novel spiropyran (SP)-based organic-inorganic composite nanogel (NG), which was prepared using upconverting nanoparticles, spiropyran, acrylic acid and N,N'-bis(acryloyl)cystamine (BAC) compounds under emulsion polymerisation. Compared with other polymer nanoparticles, the crosslinked multi-stimulus responsive nanogels can adjust the release rate by altering more of the parameters and this can meet the needs of a complex biological environment to control the release of drugs. Doxorubicin hydrochlorides were used as a simulated drug to test the drug loading performance and controllable drug release performance of the composite NGs. Under near-infrared light (NIR) irradiation, an acidic environment or a reducing agent, the delivery of the loaded drugs was by controlled release over 24 hours. Under mild triple stimulation (NIR light, pH 6, and 4 mM reducing agent), the loaded drug could be released more efficiently. The organic-inorganic composite NGs with highly-efficient and controllable release performance for loaded drugs provide many choices for novel stimulus responsive nanocarriers.


Asunto(s)
Sustancias Reductoras , Nanogeles , Preparaciones de Acción Retardada , Oxidación-Reducción , Concentración de Iones de Hidrógeno
6.
Eur J Oral Sci ; 131(5-6): e12955, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37805702

RESUMEN

Adenosine monophosphate-activated protein kinase (AMPK) plays pivotal roles in metabolic diseases including type 2 diabetes. However, the specific role of AMPK for orthodontic tooth movement in type 2 diabetes is unclear. In this study, a diabetic rat model was established through dietary manipulation and streptozocin injection. Examinations were conducted to select qualified type 2 diabetic rats. Then, an orthodontic device was applied to these rats for 0, 3, 7, or 14 days. The distance of orthodontic tooth movement and parameters of alveolar bone were analyzed by micro-computed tomography. Periodontal osteoclastic activity, inflammatory status, and AMPK activity were measured via histological analyses. Next, we repeated the establishment of diabetic rats to investigate whether change of AMPK activity was associated with orthodontic tooth movement under type 2 diabetes. The results showed that diabetic rats exhibited an exacerbated alveolar bone resorption, overactive inflammation, and decreased periodontal AMPK activity during orthodontic tooth movement. Injection of the AMPK agonist alleviated type 2 diabetes-induced periodontal inflammation and alveolar bone resorption, thus normalizing distance of orthodontic tooth movement. Our study indicates that type 2 diabetes decreases periodontal AMPK activity, leading to excessive inflammation elevating osteoclast formation and alveolar bone resorption, which could be reversed by AMPK activation.


Asunto(s)
Pérdida de Hueso Alveolar , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Ratas , Animales , Diabetes Mellitus Tipo 2/complicaciones , Técnicas de Movimiento Dental/métodos , Microtomografía por Rayos X , Proteínas Quinasas Activadas por AMP , Pérdida de Hueso Alveolar/diagnóstico por imagen , Inflamación , Ligamento Periodontal
7.
Int J Mol Sci ; 24(10)2023 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-37240036

RESUMEN

Medication-related osteonecrosis of the jaw (MRONJ) is a severe disease with unclear pathogenesis. Adipose tissue-derived mesenchymal stromal cells (MSC(AT)s) serve as a special source for cell therapy. Herein, we explored whether exosomes (Exo) derived from MSC(AT)s promote primary gingival wound healing and prevent MRONJ. An MRONJ mice model was constructed using zoledronate (Zol) administration and tooth extraction. Exosomes were collected from the conditioned medium (CM) of MSC(AT)s (MSC(AT)s-Exo) and locally administered into the tooth sockets. Interleukin-1 receptor antagonist (IL-1RA)-siRNA was used to knock down the expression of IL-1RA in MSC(AT)s-Exo. Clinical observations, micro-computed tomography (microCT), and histological analysis were used to evaluate the therapeutic effects in vivo. In addition, the effect of exosomes on the biological behavior of human gingival fibroblasts (HGFs) was evaluated in vitro. MSC(AT)s-Exo accelerated primary gingival wound healing and bone regeneration in tooth sockets and prevented MRONJ. Moreover, MSC(AT)s-Exo increased IL-1RA expression and decreased interleukin-1 beta (IL-1ß) and tumor necrosis factor-α (TNF-α) expression in the gingival tissue. The sequent rescue assay showed that the effects of preventing MRONJ in vivo and improving the migration and collagen synthesis abilities of zoledronate-affected HGFs in vitro were partially impaired in the IL-1RA-deficient exosome group. Our results indicated that MSC(AT)s-Exo might prevent the onset of MRONJ via an IL-1RA-mediated anti-inflammatory effect in the gingiva wound and improve the migration and collagen synthesis abilities of HGFs.


Asunto(s)
Exosomas , Células Madre Mesenquimatosas , Osteonecrosis , Ratones , Animales , Humanos , Ácido Zoledrónico , Proteína Antagonista del Receptor de Interleucina 1/genética , Proteína Antagonista del Receptor de Interleucina 1/metabolismo , Exosomas/metabolismo , Microtomografía por Rayos X , Osteonecrosis/metabolismo , Células Madre Mesenquimatosas/metabolismo , Colágeno/metabolismo
8.
BMC Oral Health ; 23(1): 621, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37658390

RESUMEN

BACKGROUND: Reconstruction of the temporomandibular joint (TMJ) is a significant challenge in maxillofacial surgery. A vascularized medial femoral condyle (MFC) osteocartilaginous flap is a good choice for TMJ reconstruction. In this study, we evaluated the radiographic and histological changes of MFC after TMJ reconstruction. METHODS: A ramus-condyle unit (RCU) defect was created unilaterally in five adult male Bama miniature pigs. The ipsilateral vascularized MFC osteocartilaginous flap was used to reconstruct the TMJ, and the non-operative sides served as controls. Multislice spiral computed tomography (CT) was performed preoperatively, immediately postoperatively, and at two weeks, three months, and six months postoperatively. Three animals were euthanized at 6 months postoperatively. Their reconstructed condyles, natural condyles and the MFCs on the opposite side were collected and subjected to µCT and histological evaluation. RESULTS: In the miniature pigs, the vascularized MFC osteocartilaginous flap was fused to the mandible, thus restoring the structure and function of the RCU. The postoperative radiographic changes and histological results showed that the reconstructed condyle was remodeled toward the natural condyle, forming a similar structure, which was significantly different from the MFC. CONCLUSIONS: In miniature pigs, the RCU can be successfully reconstructed by vascularized osteocartilaginous MFC flap. The reconstructed condyle had almost the same appearance and histological characteristics as the natural condyle.


Asunto(s)
Cirugía Bucal , Articulación Temporomandibular , Masculino , Animales , Porcinos , Porcinos Enanos , Articulación Temporomandibular/diagnóstico por imagen , Articulación Temporomandibular/cirugía , Mandíbula , Polímeros
9.
BMC Oral Health ; 23(1): 14, 2023 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-36627695

RESUMEN

BACKGROUND: Medication-related osteonecrosis of the jaw (MRONJ) is a serious debilitating disease caused by anti-resorption and anti-angiogenesis drugs, significantly affecting patients' quality of life. Recent studies suggested that primary gingival wound healing may effectively prevent the development of MRONJ. This study aimed to evaluate the effects of low-level light therapy (LLLT) on promoting gingival wound healing in extraction sockets of MRONJ-like mice and preventing the occurrence of MRONJ. Furthermore, we explored underlying mechanisms. METHODS: Mice were randomly divided into the Ctrl, Zol, and Zol + LLLT groups. Administration of zoledronate and tooth extraction of bilateral maxillary second molars were used to build the MRONJ model, and LLLT was locally administered into the tooth sockets to examine the effect of LLLT. Next, to explore the function of IL-1RA, we performed LLLT with interleukin-1 receptor antagonist (IL-1RA) neutralizing antibody (named Zol + LLLT + IL-1RA NAb group) or negative control antibodies for tooth extraction in subsequent rescue animal experiments. Stereoscope observations, micro-computed tomography, and histological examination were conducted to evaluate gingival wound healing and bone regeneration in tooth sockets. The effects of LLLT on the migration capacities of zoledronate-treated epithelial cells were assessed in vitro. RESULTS: LLLT promoted primary gingival wound healing without exposed necrotic bone. Micro-computed tomography results showed higher bone volume and mineral density of the tooth sockets after LLLT. Histology analysis showed complete gingival coverage, obvious bone regeneration, and reduced soft tissue inflammation, with down-regulated pro-inflammation cytokines, like interleukin-1 beta (IL-1ß) and tumor necrosis factor-α (TNF-α), and up-regulated IL-1RA expression in the gingival tissue in the LLLT group. The rescue assay further showed that the effects of LLLT promoting gingival wound healing and preventing MRONJ might be partially abolished by IL-1RA neutralizing antibodies. In vitro studies demonstrated that LLLT accelerated zoledronate-treated epithelial cell migration. CONCLUSIONS: LLLT might promote primary gingival wound healing and contribute to subsequent bone regeneration of the tooth extractions in MRONJ-like lesions via IL-1RA-mediated pro-inflammation signaling suppression.


Asunto(s)
Osteonecrosis de los Maxilares Asociada a Difosfonatos , Conservadores de la Densidad Ósea , Enfermedades de las Encías , Terapia por Luz de Baja Intensidad , Animales , Ratones , Osteonecrosis de los Maxilares Asociada a Difosfonatos/prevención & control , Conservadores de la Densidad Ósea/efectos adversos , Difosfonatos/efectos adversos , Enfermedades de las Encías/radioterapia , Proteína Antagonista del Receptor de Interleucina 1/metabolismo , Calidad de Vida , Extracción Dental , Cicatrización de Heridas , Microtomografía por Rayos X , Ácido Zoledrónico/efectos adversos
10.
Oral Dis ; 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-36050281

RESUMEN

OBJECTIVE: This study aims to clarify the effects of diabetes mellitus (DM) on inflammatory profile during orthodontic tooth movement (OTM) and explore potential mechanisms. METHODS: OTM models were established in healthy (Ctrl) and DM rats for 0, 3, 7 or 14 days. The tooth movement distance and bone structural parameters were analyzed through micro-CT. The bone resorption activity and periodontal inflammation status were evaluated through histological staining. RNA sequencing was performed to detect differentially expressed genes in force loading-treated periodontal ligament fibroblasts (PDLFs) with or without high glucose. The differential expression of inflammatory genes associated with NOD-like receptor family pyrin domain containing 3 (NLRP3) between groups was tested in vitro and in vivo. RESULTS: DM caused remarkable reduction of alveolar bone height and density around the moved tooth, corresponding with the higher bone resorption activity and inflammatory scores of DM group. For force loading-treated PDLFs, high glucose induced the activation of inflammatory pathways, including NLRP3. Elevated expression of NLRP3 and cascade molecules (Caspase-1, GSDMD, and IL-1ß) were validated by RT-qPCR, Western blot, and immunohistochemistry staining. CONCLUSIONS: DM alters the inflammatory status of periodontium and affects tissue reconstruction during OTM. NLRP3 inflammasome may involve in diabetes-induced periodontal changes.

11.
Clin Oral Investig ; 26(1): 1003-1016, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34363103

RESUMEN

OBJECTIVES: The aim of this study was to investigate cementocyte mechanotransduction during excessive orthodontic intrusive force-induced root resorption and the role of S1P signaling in this process. MATERIALS AND METHODS: Fifty-four 12-week-old male Wistar rats were randomly divided into 3 groups: control group (Control), intrusive stress application group (Stress), and intrusive stress together with S1PR2-specific antagonist injection group (Stress + JTE). A rat molar intrusion model was established on animals in the Stress and the Stress + JTE groups. The animals in the Stress + JTE group received daily intraperitoneal (i.p.) injection of S1PR2 antagonist JTE-013, while the Control and Stress groups received only the vehicle. Histomorphometric, immunohistochemical, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analyses were performed after euthanizing of the rats. RESULTS: Root resorption was promoted in the Stress group with increased volumes of resorption pits and amounts of molar intrusion compared with the Control group. The expression levels of cementogenic- and cementoclastic-related factors were affected under excessive intrusive force. Immunohistochemical staining and qRT-PCR analysis showed promoted S1P signaling activities during molar intrusion. Western blot analysis indicated decreased nuclear translocation of ß-catenin under excessive intrusive force. Through the administration of JTE-013, S1P signaling activity was suppressed and excessive intrusive force-induced root resorption was reversed. The regulation of S1P signaling could also influence the nuclear translocation of ß-catenin and the expressions of cementogenic- and cementoclastic-related factors. CONCLUSIONS: Root resorption was promoted under excessive orthodontic intrusive force due to the disruption of cementum homeostasis. S1P signaling pathway might play an important role in cementocyte mechanotransduction in this process. CLINICAL RELEVANCE: The S1P signaling might be a promising therapeutic target for novel therapeutic approaches to prevent external root resorption caused by excessive orthodontic intrusive force.


Asunto(s)
Resorción Radicular , Animales , Lisofosfolípidos , Masculino , Mecanotransducción Celular , Diente Molar , Ratas , Ratas Wistar , Transducción de Señal , Esfingosina/análogos & derivados , Técnicas de Movimiento Dental
12.
J Oral Maxillofac Surg ; 79(12): 2472-2481, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34481810

RESUMEN

PURPOSE: The treatment of medication-related osteonecrosis of the jaw (MRONJ) is greatly challenging for surgeons. In this study, we reviewed patients with MRONJ treated in our hospital in the past 5 years and explored the risk factors of recurrence. METHODS: A retrospective cohort study was conducted to review the patients with MRONJ from January 1, 2016 to December 31, 2020. All patients received a monthly intravenous application of zoledronic acid. The primary outcome variable was the treatment outcome during follow-up. The predictor variables were local and systemic factors related to the treatment outcome. Multivariate logistic regression analysis was performed to identify the risk factors of recurrence after MRONJ treatment. RESULTS: A total of 58 patients (62 sites) were included in this study. In multivariate regression analysis, the risk factor associated with recurrence after MRONJ treatment was the duration of medication of more than 18 months (odds ratio = 7.346; 95% confidence interval: 1.461-36.946; P = .016). CONCLUSIONS: Using zoledronic acid over 18 months may increase the risk of recurrence in MRONJ patients.


Asunto(s)
Osteonecrosis de los Maxilares Asociada a Difosfonatos , Conservadores de la Densidad Ósea , Conservadores de la Densidad Ósea/efectos adversos , Difosfonatos/efectos adversos , Humanos , Maxilares , Estudios Retrospectivos , Ácido Zoledrónico/efectos adversos
13.
J Cell Biochem ; 121(3): 2478-2488, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31692090

RESUMEN

Cellular differentiation is caused by highly controlled modifications in the gene expression but rarely involves a change in the DNA sequence itself. Histone acetylation is a major epigenetic factor that adds an acetyl group to histone proteins, thus altering their interaction with DNA and nuclear proteins. Illumination of the histone acetylation during dentinogenesis is important for odontoblast differentiation and dentinogenesis. In the current study, we aimed to discover the roles and regulation of acetylation at histone 3 lysine 9 (H3K9ac) and H3K27ac during dentinogenesis. We first found that both of these modifications were enhanced during odontoblast differentiation and dentinogenesis. These modifications are dynamically catalyzed by histone acetyltransferases (HATs) and deacetylases (HDACs), among which HDAC3 was decreased while p300 increased during odontoblast differentiation. Moreover, overexpression of HDAC3 or knockdown p300 inhibited odontoblast differentiation in vitro, and inhibition of HDAC3 and p300 with trichostatin A or C646 regulated odontoblast differentiation. Taken together, the results of our present study suggest that histone acetylation is involved in dentinogenesis and coordinated expression of p300- and HDAC3-regulated odontoblast differentiation through upregulating histone acetylation.


Asunto(s)
Papila Dental/citología , Dentinogénesis , Proteína p300 Asociada a E1A/metabolismo , Histona Desacetilasas/metabolismo , Histonas/química , Células Madre Mesenquimatosas/citología , Procesamiento Proteico-Postraduccional , Acetilación , Animales , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Papila Dental/metabolismo , Proteína p300 Asociada a E1A/genética , Histona Desacetilasas/genética , Células Madre Mesenquimatosas/metabolismo , Ratones
14.
Environ Sci Technol ; 54(23): 15433-15441, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33196185

RESUMEN

Graphene oxide (GO) is promising for constructing next-generation high-performance membranes for water treatment and desalination. However, GO-based membranes are still subjected to low ion rejection or limited water flux. Herein, the electrokinetic effect is employed as a new strategy for the coenhancement of water flux and ion rejection through an ethylenediamine-polystyrenesulfonate intercalated graphene oxide/carbon nanotube (GO&EDA-PSS/CNT) asymmetric membrane. Benefiting from the external voltage applied across the GO&EDA-PSS layer, the electrokinetically driven water transport velocity is significantly increased from 0 to 23.7 µm s-1 with increasing the voltage from 0 to 3.0 V. As a result, the water flux is improved from 9.1 to 17.4 L m-2 h-1 under a transmembrane pressure of 1 bar. Simultaneously, the rejection rate for NaCl is increased from 52.4% to 78.3%. Numerical analysis reveals that the increased rejection rate is attributed to the electrokinetic enhancements of water transport through the membrane and ion partitioning between the membrane and bulk solution. These results indicate that the assistance of the electrokinetic effect is an effective means to improve membrane filtration performance, which provides a new perspective on the design of advanced membranes for achieving high water flux and rejection efficiency.


Asunto(s)
Grafito , Nanotubos de Carbono , Membranas Artificiales , Agua
15.
J Cell Biochem ; 120(9): 14688-14699, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31009133

RESUMEN

OBJECTIVE: DNA methylation is a critical epigenetic modulation in regulating gene expression in cell differentiation process, however, its detailed molecular mechanism during odontoblastic differentiation remains elusive. We aimed to study the global effect of DNA methylation on odontoblastic differentiation and how DNA methylation affects the transactivation of transcription factor (TF) on its target gene. METHODS: DNA methyltransferase (DNMTs) inhibition assay and following odontoblastic differentiation assay were performed to evaluate the effect of DNA methylation inhibition on odontoblastic differentiation. Promoter DNA methylation microarray and motif enrichment assay were performed to predict the most DNA-methylation-affected TF motifs during odontoblastic differentiation. The enriched target sites and motifs were further analyzed by methylation-specific polymerase chain reaction (MS-PCR) and sequencing. The functional target sites were validated in vitro with Luciferase assay. The regulatory effect of DNA methylation on the enriched target sites in primary human dental pulp cells and motifs were confirmed by in vitro methylation assay. RESULTS: Inhibition of DNMTs in preodontoblast cells increased the expression level of Klf4 as well as marker genes of odontoblastic differentiation including Dmp1 and Dspp, and enhanced the efficiency of odontoblastic differentiation. SP1/KLF4 binding motifs were found to be highly enriched in the promoter regions and showed demethylation during odontoblastic differentiation. Mutation of SP1 binding site at -75 within KLF4's promoter region significantly decreased the luciferase activity. The in vitro methylation of KLF4's promoter decreased the transactivation of SP1 on KLF4. CONCLUSION: We confirmed that SP1 regulates KLF4 through binding site lying in a CpG island in KLF4's promoter region which demethylated during odontoblastic differentiation thus enhancing the efficiency of SP1's binding and transcriptional regulation on KLF4.


Asunto(s)
Diferenciación Celular , Metilación de ADN , Pulpa Dental/citología , Regulación de la Expresión Génica , Factores de Transcripción de Tipo Kruppel/metabolismo , Odontoblastos/citología , Factor de Transcripción Sp1/metabolismo , Animales , Apoptosis , Proliferación Celular , Células Cultivadas , Islas de CpG , ADN (Citosina-5-)-Metiltransferasa 1/genética , ADN (Citosina-5-)-Metiltransferasa 1/metabolismo , Pulpa Dental/metabolismo , Humanos , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Ratones , Odontoblastos/metabolismo , Regiones Promotoras Genéticas , Factor de Transcripción Sp1/genética
16.
Environ Sci Technol ; 53(9): 5292-5300, 2019 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-30933494

RESUMEN

Excellent fouling resistance to various foulants is crucial to maintain the separation performance of membranes in providing potable water. Antimicrobial modification is effective for antibiofouling but fails to mitigate organic fouling. Improving surface charges can improve the resistance to charged foulants, but the lack of antimicrobial ability results in bacterial aggregation. Herein, a silver nanoparticle modified carbon nanotube (Ag-CNT)/ceramic membrane was prepared with enhanced antifouling and antimicrobial properties under electrochemical assistance. The presence of silver nanoparticles endows the composite membrane with antimicrobial ability by which biofilm formation is inhibited. Its steady-state flux is 1.9 times higher than that for an unmodified membrane in filtering bacterial suspension. Although the formation of organic fouling did weaken the biofouling resistance, the negatively charged bacteria and organic matter can be sufficiently repelled away from the cathodic membrane under electrochemical assistance. The flux loss under a low-voltage of 2.0 V decreased to <10% from >35% for the membrane alone when bacteria and organic matter coexisted in the feedwater. More importantly, silver dissolution was significantly inhibited via an in situ electroreduction process by which the Ag+ concentration in the effluent (<1.0 µg/L) was about 2 orders of magnitude lower than that without voltage. The integration of antimicrobial modification and electrochemistry offers a new prospect in the development of membranes with high fouling resistance in water treatment.


Asunto(s)
Antiinfecciosos , Incrustaciones Biológicas , Nanopartículas del Metal , Nanotubos de Carbono , Membranas Artificiales , Plata
17.
Environ Sci Technol ; 53(2): 868-877, 2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30540165

RESUMEN

Nanofiltration (NF) is considered a promising candidate for brackish and seawater desalination. NF exhibits high multivalent ion rejection, but the rejection rate for monovalent ions is relatively low. Besides, great challenges remain for conventional NF membranes to achieve high ion rejection without sacrificing water flux. This work presents an effective strategy for improving the ion rejection of conductive NF membrane without decreasing the permeability through electrically assisted enhancement of surface charge density. When external voltage is increased from 0 to 2.5 V, the surface charge density of the membrane increases from 11.9 to 73.0 mC m-2, which is 6.1× higher than that without external voltage. Correspondingly, the rejection rate for Na2SO4 increases from 81.6 to 93.0% and that for NaCl improves from 53.9 to 82.4%; meanwhile, the membrane retains high permeabilities of 14.0 L m-2 h-1 bar-1 for Na2SO4 filtration and 14.5 L m-2 h-1 bar-1 for NaCl filtration. The Donnan steric pore model analysis suggests that the Donnan potential difference between the membrane and bulk solution is increased under electrical assistance, leading to increased ion transfer resistance for improved ion rejection. This work provides new insight into the development of advanced NF technologies for desalination and water treatment.


Asunto(s)
Membranas Artificiales , Purificación del Agua , Conductividad Eléctrica , Filtración , Iones
18.
Orthod Craniofac Res ; 22 Suppl 1: 134-141, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31074144

RESUMEN

OBJECTIVES: Enamel organ epithelium (EOE) gives rise to the major epithelial-derived cell types of tooth including the ameloblasts. The formation of enamel, termed amelogenesis, occurs through the cytodifferentiation of ameloblasts, ultimately leading to apoptosis and necrosis of these cells with eruption. Therefore, studies regarding enamel matrix formation and bioengineering have been limited. In this study, we establish and characterize two mouse immortalized ameloblast-like cell lines using human papillomavirus 16 (HPV16) E6/E7 oncogenes for the first time. SETTING AND SAMPLE POPULATION: Two mouse EOE dental cell lines (EOE-2M and EOE-3M). MATERIAL AND METHODS: Isolated EOE primary cells were used to establish clonal cell lines and immortalized using the HPV16 E6/E7 gene platform. Two established cell lines were characterized by growth rate (Cell Proliferation Assay, MTS), gene (quantitative RT-PCR) and protein (immunocytochemistry) expression profiles, and mineralization potential (in situ alkaline phosphatase (ALP) histochemistry and Xylene Orange staining) in media supplemented with ascorbic acid and ß-glycerophosphate. Gene and protein expression analyses included specific enamel matrix and ameloblast cell markers: Amel, Ambn, Enam, Amtn, ODAM, MMP20, Krt14 and DLX3. RESULTS: Both cell lines were maintained in excess of 30 passages, with EOE-3M cells proliferating at a slightly higher rate. The cell lines expressed all tested enamel matrix markers and produced a mineralized ECM demonstrating an ameloblast-like profile. CONCLUSIONS: Two mouse ameloblasts-like immortalized cell lines have been characterized that will be useful tool for studies regarding enamel bioengineering.


Asunto(s)
Ameloblastos , Línea Celular , Diente , Amelogénesis , Animales , Esmalte Dental , Proteínas del Esmalte Dental , Humanos , Ratones
19.
Sensors (Basel) ; 19(15)2019 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-31387246

RESUMEN

The development of sensors with high sensitivity, good flexibility, low cost, and capability of detecting multiple inputs is of great significance for wearable electronics. Herein, we report a napkin-based wearable capacitive sensor fabricated by a novel, low-cost, and facile strategy. The capacitive sensor is composed of two pieces of electrode plates manufactured by spontaneous assembly of silver nanowires (NWs) on a polydimethylsiloxane (PDMS)-patterned napkin. The sensor possesses high sensitivity (>7.492 kPa-1), low cost, and capability for simultaneous detection of multiple signals. We demonstrate that the capacitive sensor can be applied to identify a variety of human physiological signals, including finger motions, eye blinking, and minute wrist pulse. More interestingly, the capacitive sensor comfortably attached to the temple can simultaneously monitor eye blinking and blood pulse. The demonstrated sensor shows great prospects in the applications of human-machine interface, prosthetics, home-based healthcare, and flexible touch panels.


Asunto(s)
Monitoreo Fisiológico/métodos , Dispositivos Electrónicos Vestibles , Parpadeo/fisiología , Dimetilpolisiloxanos/química , Dedos/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Monitoreo Fisiológico/instrumentación , Nanocables/química , Plata/química , Dispositivos Electrónicos Vestibles/economía
20.
Environ Sci Technol ; 52(3): 1444-1452, 2018 02 06.
Artículo en Inglés | MEDLINE | ID: mdl-29294271

RESUMEN

Forward osmosis (FO) is an emerging approach in water treatment, but its application is restricted by severe internal concentration polarization (ICP) and low flux. In this work, a self-sustained carbon nanotube hollow fiber scaffold supported polyamide thin film composite (CNT TFC-FO) membrane was first proposed with high porosity, good hydrophilicity and excellent electro-conductivity. It showed a specific structure parameter as low as 126 µm, suggesting its weakened ICP. Against a pure water feed using 2.0 M NaCl draw solution, its fluxes were 4.7 and 3.6 times as high as those of the commercial cellulose triacetate TFC-FO membrane in the FO and pressure retarded osmosis (PRO) modes, respectively. Meanwhile, the membrane showed excellent electrically assisted resistance to organic and microbial fouling. Its flux was improved by about 50% during oil-water simulation separation under 2.0 V voltage. These results indicate that the CNT TFC-FO membrane opens up a frontier for stably and effectively recycling potable water from electrochemical FO process.


Asunto(s)
Nanotubos de Carbono , Purificación del Agua , Membranas Artificiales , Ósmosis , Aguas Residuales
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA