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1.
Adv Mater ; 36(34): e2309818, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38288578

RESUMEN

The growth of multicellular organisms is a process akin to additive manufacturing where cellular proliferation and mechanical boundary conditions, among other factors, drive morphogenesis. Engineers have limited ability to engineer morphogenesis to manufacture goods or to reconfigure materials comprised of biomass. Herein, a method that uses biological processes to grow and regrow magnetic engineered living materials (mELMs) into desired geometries is reported. These composites contain Saccharomyces cerevisiae and magnetic particles within a hydrogel matrix. The reconfigurable manufacturing process relies on the growth of living cells, magnetic forces, and elastic recovery of the hydrogel. The mELM then adopts a form in an external magnetic field. Yeast within the material proliferates, resulting in 259 ± 14% volume expansion. Yeast proliferation fixes the magnetic deformation, even when the magnetic field is removed. The shape fixity can be up to 99.3 ± 0.3%. The grown mELM can recover up to 73.9 ± 1.9% of the original form by removing yeast cell walls. The directed growth and recovery process can be repeated at least five times. This work enables ELMs to be processed and reprocessed into user-defined geometries without external material deposition.


Asunto(s)
Hidrogeles , Saccharomyces cerevisiae , Saccharomyces cerevisiae/citología , Hidrogeles/química , Campos Magnéticos , Proliferación Celular/efectos de los fármacos
2.
Soft Matter ; 19(12): 2254-2264, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36916641

RESUMEN

The bundling of flagella is known to create a "run" phase, where the bacteria moves in a nearly straight line rather than making changes in direction. Historically, mechanical explanations for the bundling phenomenon intrigued many researchers, and significant advances were made in physical models and experimental methods. Contributing to the field of research, we present a bacteria-inspired centimeter-scale soft robotic hardware platform and a computational framework for a physically plausible simulation model of the multi-flagellated robot under low Reynolds number (∼10-1). The fluid-structure interaction simulation couples the discrete elastic rods algorithm with the method of regularized Stokeslet segments. Contact between two flagella is handled by a penalty-based method. We present a comparison between our experimental and simulation results and verify that the simulation tool can capture the essential physics of this problem. Preliminary findings on robustness to buckling provided by the bundling phenomenon and the efficiency of a multi-flagellated soft robot are compared with the single-flagellated counterparts. Observations were made on the coupling between geometry and elasticity, which manifests itself in the propulsion of the robot by nonlinear dependency on the rotational speed of the flagella.

3.
Bioinspir Biomim ; 18(1)2022 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-36533860

RESUMEN

Flagella and cilia are slender structures that serve important functionalities in the microscopic world through their locomotion induced by fluid and structure interaction. With recent developments in microscopy, fabrication, biology, and modeling capability, robots inspired by the locomotion of these organelles in low Reynolds number flow have been manufactured and tested on the micro-and macro-scale, ranging from medicalin vivomicrobots, microfluidics to macro prototypes. We present a collection of modeling theories, control principles, and fabrication methods for flagellated and ciliary robots.


Asunto(s)
Cilios , Flagelos , Locomoción
4.
BMB Rep ; 55(7): 361, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35892133

RESUMEN

[Erratum to: BMB Reports 2022; 55(3): 136-141, PMID: 34488927, PMCID: PMC8972135] The BMB Reports would like to correct in BMB Rep. 55(3):136-141, titled "Human umbilical cord mesenchymal stem cell-derived mitochondria (PN-101) attenuate LPS-induced inflammatory responses by inhibiting NFκB signaling pathway". This research was supported by NRF-2016R1A2B4007640 grant (to C-H Kim). Since grant number is incorrect, this information has now been corrected as follows: We would like to thank various Paean Biotechnology Inc. members who participated in the project. This work was supported by NRF-2018M3A9B5023055 grant (to C-H Kim). The authors apologize for any inconvenience or confusion that may be caused by this error. The ACKNOWLEDGEMENTS of Original PDF version have been corrected.

5.
BMB Rep ; 55(3): 136-141, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34488927

RESUMEN

Inflammation is one of the body's natural responses to injury and illness as part of the healing process. However, persistent inflammation can lead to chronic inflammatory diseases and multi-organ failure. Altered mitochondrial function has been implicated in several acute and chronic inflammatory diseases by inducing an abnormal inflammatory response. Therefore, treating inflammatory diseases by recovering mitochondrial function may be a potential therapeutic approach. Recently, mitochondrial transplantation has been proven to be beneficial in hyperinflammatory animal models. However, it is unclear how mitochondrial transplantation attenuates inflammatory responses induced by external stimuli. Here, we isolated mitochondria from umbilical cord-derived mesenchymal stem cells, referred as to PN-101. We found that PN-101 could significantly reduce LPS-induced mortality in mice. In addition, in phorbol 12-myristate 13-acetate (PMA)-treated THP-1 macrophages, PN-101 attenuated LPS-induced increase production of pro-inflammatory cytokines. Furthermore, the anti-inflammatory effect of PN-101 was mediated by blockade of phosphorylation, nuclear translocation, and trans-activity of NFκB. Taken together, our results demonstrate that PN-101 has therapeutic potential to attenuate pathological inflammatory responses. [BMB Reports 2022; 55(3): 136-141].


Asunto(s)
Lipopolisacáridos , Células Madre Mesenquimatosas , Animales , Citocinas/metabolismo , Humanos , Inflamación/inducido químicamente , Inflamación/metabolismo , Lipopolisacáridos/farmacología , Células Madre Mesenquimatosas/metabolismo , Ratones , Mitocondrias/metabolismo , FN-kappa B/metabolismo , Transducción de Señal , Cordón Umbilical/metabolismo
6.
ACS Appl Mater Interfaces ; 12(22): 25253-25265, 2020 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-32367709

RESUMEN

This paper presents a new surface modification strategy to develop a poly(ethylene terephthalate) (PET)-based membrane having a hydrophilic surface, high nutrient ion permeability, sufficient mechanical strength, and organic fouling resistance, using an anthracene (ANT)-attached polyethylene glycol (PEG) surface modification agent (SMA) synthesized in this work. During the modification process, the ANT parts of the SMAs poke through and anchor to the surface of a commercial PET woven fabric via physical interactions and mechanical locking. The PEG chain parts coat the surface in the brush and arch forms, which generates a hydration layer on the fabric surface. The consequently obtained surface property and unique structure of the modified PET-based membrane result in higher nitrate ion permeability, organic fouling resistance, and microalgae production compared to those of the unmodified one. These are also affected by the molecular weight of the PEG and the number density of the anchored SMAs. The study demonstrates that this new surface modification method has the potential to allow the development of a desirable PET-based membrane for the efficient massive production of marine microalgae.


Asunto(s)
Incrustaciones Biológicas/prevención & control , Chlorophyta/crecimiento & desarrollo , Técnicas de Cultivo/instrumentación , Membranas Artificiales , Microalgas/crecimiento & desarrollo , Tereftalatos Polietilenos/química , Antracenos/química , Reactores Biológicos/microbiología , Permeabilidad , Polietilenglicoles/química , Propiedades de Superficie
7.
Bioresour Technol ; 251: 288-294, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29288957

RESUMEN

Oils and fatty acids are important renewable resources provided by nature. Therefore, biotransformation of renewable oils and fatty acids into industrially relevant C9 chemicals was investigated in this study. Olive oil, soybean oil, yeast derived oil, and microalgae fatty acid methyl esters were converted into n-nonanoic acid, 9-hydroxynonanoic acid, and 1,9-nonanedioic acid by a lipase and a recombinant Escherichia coli expressing oleate hydratase, long chain secondary alcohol dehydrogenase, Baeyer-Villiger monooxygenase, long chain primary alcohol dehydrogenase, and aldehyde dehydrogenase. It was found that n-nonanoic acid and azelaic acid could be produced to a concentration of 4.3 mM from 3 g/L olive oil with a specific product formation rate of 3.1 U/g dry cells. Biotransformation rates were influenced by compositions of fatty acids and purity of the starting material. This study may contribute to the production of industrially relevant C9 chemicals from renewable oils and fatty acids by simultaneous enzyme/whole-cell biotransformation.


Asunto(s)
Ácidos Grasos , Microalgas , Biotransformación , Ácidos Dicarboxílicos , Ésteres , Aceites de Plantas
8.
J Endod ; 43(11): 1857-1861, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28951032

RESUMEN

INTRODUCTION: The aim of this study was to assess the antifungal efficacy of a synthetic human beta-defensin-3-C15 peptide (HBD3-C15) in Candida albicans-infected human root dentin. METHODS: Standardized root dentin blocks were prepared (6-mm thick, 0.7-mm-wide canal) from single-rooted human permanent premolars and infected with C. albicans for 3 weeks. They were randomly divided into 4 groups (n = 8/group), and their canals were filled with calcium hydroxide (CH), HBD3-C15 peptide, or chlorhexidine digluconate (CHX, 2%) as disinfectants or saline as control. After 1 week of disinfection, dentinal debris were harvested at depths of 200 and 400 µm from the canal lumen, and incubated in Yeast broth for 72 hours at 37°C. Then, colony-forming units (CFU) were measured to assess the antifungal efficacy of each medicament and analyzed statistically. RESULTS: All medicaments showed significantly lower CFU than saline (P < .05), and their antifungal efficacies were similar at both 200- and 400-µm tubular depths (P > .05). HBD3-C15 had similar antifungal efficacy to that of CHX at both depths (P > .05), and both medicaments had significantly lower CFU than CH at both depths (P < .05). CONCLUSIONS: In this ex vivo model of C. albicans-infected human root dentin, the antifungal efficacy of synthetic HBD3-C15 was comparable with CHX.


Asunto(s)
Antifúngicos/uso terapéutico , Candidiasis Bucal/tratamiento farmacológico , Dentina/microbiología , Raíz del Diente/microbiología , beta-Defensinas/uso terapéutico , Humanos
9.
Photomed Laser Surg ; 35(2): 71-77, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27929924

RESUMEN

OBJECTIVE: The aim of this study was to compare the effectiveness of five intracanal agitation techniques on the penetration of irrigant and sealer into dentinal tubules. BACKGROUND DATA: Intracanal agitation techniques could promote chemomechanical debridement and the sealing of root canals during endodontic treatment. However, there is limited evidence for the agitation effect of Nd:YAP laser. MATERIALS AND METHODS: Human maxillary premolars with single straight canals (N = 60) were prepared with ProTaper Next® NiTi rotary files (Dentsply Maillefer) up to X4 (ISO 40 size). Rhodamine B-labeled sodium hypochlorite was used for final irrigation together with the conventional syringe (control), sonic, ultrasonic, Nd:YAP laser, or V-Clean™ endodontic agitation system. All canals were obturated with gutta-percha and fluorescein isothiocyanate-labeled AH Plus sealer. Transverse sections were obtained at 2, 5, and 8 mm from the apex and observed under confocal laser scanning microscopy. Maximum penetration depth and penetration percentage of both irrigant and sealer were recorded. Kruskal-Wallis and Mann-Whitney tests were performed for multiple comparisons. The Spearman coefficient was calculated to confirm correlations between irrigant and sealer penetration. RESULTS: Laser agitation attained the most irrigant and sealer penetration depth and penetration percentage (p < 0.05). Sonic and ultrasonic agitation attained significantly more penetration percentage than the control group at 2 mm from the apex (p < 0.05). Patterns of irrigant and sealer penetration correlated significantly for all agitation techniques (p < 0.001). CONCLUSIONS: Nd:YAP laser was superior to other agitation techniques in dentinal tubule penetration of irrigant and sealer at one or more sectioned levels from the apex.


Asunto(s)
Dentina/efectos de los fármacos , Láseres de Estado Sólido/uso terapéutico , Irrigantes del Conducto Radicular/farmacología , Diente Premolar/cirugía , Dentina/química , Resinas Epoxi , Humanos , Microscopía Confocal/métodos , Preparación del Conducto Radicular/métodos , Sensibilidad y Especificidad , Hipoclorito de Sodio/farmacología
10.
J Dent Sci ; 12(1): 14-20, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30895018

RESUMEN

BACKGROUND/PURPOSE: Heat treatment of nickel-titanium (NiTi) alloy produces a better arrangement of the crystal structure, thereby leading to increased flexibility and improved fatigue resistance or plastic behavior. This study aimed to assess the performance of various heat-treated NiTi rotary instruments in S-shaped resin canals. MATERIALS AND METHODS: Forty S-shaped resin canals were instrumented (10/group) with either Twisted Files (R-phase), WaveOne (M-wire), Hyflex CM, or V Taper 2H (CM-wire) with the same apical size and taper (25/0.08). Each S-shaped resin canal was scanned both before and after instrumentation with microcomputed tomography. Changes in canal volume and transportation were evaluated at regular intervals (0.5 mm). Differences between instruments at the apical curve, coronal curve, and straight portion of the canals were analyzed statistically. RESULTS: All tested instruments caused more transportation at the coronal rather than apical curvatures, with the exception of Twisted Files for which apical transportation was the highest for any instrument or location (P < 0.05). The transportation was mostly influenced by the alloy type rather than their cross-sectional characteristics (P < 0.05). The volumetric increase after instrumentation was similar for all tested instruments at the apical curve (P > 0.05), whereas Hyflex CM created the most conservative preparations at the coronal curve (P < 0.05). At the straight portion, volumetric changes were largest for Twisted Files and smallest for V Taper 2H (P < 0.05). CONCLUSION: Amongst heat-treated NiTi instruments, the CM-wire based instruments created the most favorable preparations in S-shaped resin canals.

11.
Restor Dent Endod ; 41(2): 91-7, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27200276

RESUMEN

OBJECTIVES: The purpose of this ex vivo study was to compare the antifungal activity of a synthetic peptide consisting of 15 amino acids at the C-terminus of human ß-defensin 3 (HBD3-C15) with calcium hydroxide (CH) and Nystatin (Nys) against Candida albicans (C. albicans) biofilm. MATERIALS AND METHODS: C. albicans were grown on cover glass bottom dishes or human dentin disks for 48 hr, and then treated with HBD3-C15 (0, 12.5, 25, 50, 100, 150, 200, and 300 µg/mL), CH (100 µg/mL), and Nys (20 µg/mL) for 7 days at 37℃. On cover glass, live and dead cells in the biomass were measured by the FilmTracer Biofilm viability assay, and observed by confocal laser scanning microscopy (CLSM). On dentin, normal, diminished and ruptured cells were observed by field-emission scanning electron microscopy (FE-SEM). The results were subjected to a two-tailed t-test, a one way analysis variance and a post hoc test at a significance level of p = 0.05. RESULTS: C. albicans survival on dentin was inhibited by HBD3-C15 in a dose-dependent manner. There were fewer aggregations of C. albicans in the groups of Nys and HBD3-C15 (≥ 100 µg/mL). CLSM showed C. albicans survival was reduced by HBD3-C15 in a dose dependent manner. Nys and HBD3-C15 (≥ 100 µg/mL) showed significant fungicidal activity compared to CH group (p < 0.05). CONCLUSIONS: Synthetic HBD3-C15 peptide (≥ 100 µg/mL) and Nys exhibited significantly higher antifungal activity than CH against C. albicans by inhibiting cell survival and biofilm.

12.
Bioprocess Biosyst Eng ; 39(5): 713-23, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26857371

RESUMEN

Culturing microalgae in the ocean has potentials that may reduce the production cost and provide an option for an economic biofuel production from microalgae. The ocean holds great potentials for mass microalgal cultivation with its high specific heat, mixing energy from waves, and large cultivable area. Suitable photobioreactors (PBRs) that are capable of integrating marine energy into the culture systems need to be developed for the successful ocean cultivation. In this study, prototype floating PBRs were designed and constructed using transparent low-density polyethylene film for microalgal culture in the ocean. To improve the mixing efficiency, various types of internal partitions were introduced within PBRs. Three different types of internal partitions were evaluated for their effects on the mixing efficiency in terms of mass transfer (k(L)a) and mixing time in the PBRs. The partition type with the best mixing efficiency was selected, and the number of partitions was varied from one to three for investigation of its effect on mixing efficiency. When the number of partitions is increased, mass transfer increased in proportion to the number of partitions. However, mixing time was not directly related to the number of partitions. When a green microalga, Tetraselmis sp. was cultivated using PBRs with the selected partition under semi-continuous mode in the ocean, biomass and fatty acid productivities in the PBRs were increased by up to 50 % and 44% at high initial cell density, respectively, compared to non-partitioned ones. The results of internally partitioned PBRs demonstrated potentials for culturing microalgae by efficiently utilizing ocean wave energy into culture mixing in the ocean.


Asunto(s)
Microalgas/metabolismo , Océanos y Mares , Fotobiorreactores , Ácidos Grasos/metabolismo , Biología Marina , Microalgas/crecimiento & desarrollo
13.
Restor Dent Endod ; 41(1): 12-21, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26877986

RESUMEN

OBJECTIVES: To evaluate the effects of three acids on the microhardness of set mineral trioxide aggregate (MTA) and root dentin, and cytotoxicity on murine macrophage. MATERIALS AND METHODS: OrthoMTA (BioMTA) was mixed and packed into the human root dentin blocks of 1.5 mm diameter and 5 mm height. Four groups, each of ten roots, were exposed to 10% citric acid (CA), 5% glycolic acid (GA), 17% ethylenediaminetetraacetic acid (EDTA), and saline for five minutes after setting of the OrthoMTA. Vickers surface microhardness of set MTA and dentin was measured before and after exposure to solutions, and compared between groups using one-way ANOVA with Tukey test. The microhardness value of each group was analyzed using student t test. Acid-treated OrthoMTA and dentin was examined by scanning electron microscope (SEM). Cell viability of tested solutions was assessed using WST-8 assay and murine macrophage. RESULTS: Three test solutions reduced microhardness of dentin. 17% EDTA demonstrated severe dentinal erosion, significantly reduced the dentinal microhardness compared to 10% CA (p = 0.034) or 5% GA (p = 0.006). 10% CA or 5% GA significantly reduced the surface microhardness of set MTA compared to 17% EDTA and saline (p < 0.001). Acid-treated OrthoMTA demonstrated microporous structure with destruction of globular crystal. EDTA exhibited significantly more cellular toxicity than the other acidic solutions at diluted concentrations (0.2, 0.5, 1.0%). CONCLUSIONS: Tested acidic solutions reduced microhardness of root dentin. Five minute's application of 10% CA and 5% GA significantly reduced the microhardness of set OrthoMTA with lower cellular cytotoxicity compared to 17% EDTA.

14.
J Dent Sci ; 11(1): 95-102, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30894953

RESUMEN

BACKGROUND/PURPOSE: Recent studies have demonstrated a high incidence of isthmuses in mandibular first molar mesial roots, and intratubular mineralization following mineral trioxide aggregate obturation. This study assessed the filling quality of three obturation techniques in the apical 5 mm of mandibular first molar mesial root canals. MATERIALS AND METHODS: Sixty extracted human mandibular first molar mesial roots with two separate canals that had interconnecting isthmuses, were prepared to an apical size of 40/0.06. They were allocated to three groups of 20 roots for obturation by either cold lateral compaction (CLC) or the continuous wave of condensation (CW) that used gutta-percha and AH Plus sealer, or by an orthograde canal obturation using OrthoMTA. The obturated roots were scanned by micro-computed tomography and assessed for the volumetric ratio (%) of gutta-percha, sealer, and OrthoMTA within the main canals or isthmuses in the apical 5 mm area. Measurements were analyzed statistically for differences among three obturation techniques. RESULTS: In the main canals, filled volume ratios were not significantly different among groups. Within isthmuses, the filled volume ratio for CLC was lower than in CW (P = 0.025) or OrthoMTA (P = 0.002). In isthmuses, the gutta-percha volume ratio in CLC was lower than in CW (P = 0.005), although the sealer volume ratio was higher than in CW (P = 0.049). CONCLUSION: CLC demonstrated lower filling densities in isthmuses in the apical region than either CW or OrthoMTA. Orthograde MTA obturation showed comparable filling quality to gutta-percha with sealer.

15.
Transplantation ; 98(10): 1040-7, 2014 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-25208321

RESUMEN

BACKGROUND: Periosteum-derived progenitor cells (PDPCs) isolated from the adult periosteum can differentiate into several specific cell types. In this study, we examined the characteristics of human PDPCs and insulin-producing cells (IPCs) differentiated from PDPCs and their ability to ameliorate hyperglycemia when transplanted into streptozotocin-induced nonobese diabetic-severe combined immunodeficiency diabetic mice. METHODS: Periosteum-derived progenitor cells were isolated from patients, expanded in culture, and subjected to a three-step differentiation protocol to produce IPCs. The expression of immunogenic, pluripotent, and pancreatic markers was examined, and glucose-stimulated insulin release in vitro was also assessed. Insulin-producing cells that differentiated from PDPCs were transplanted under the kidney capsule of streptozotocin-induced diabetic mice, and glucose levels and glucose tolerance were measured. RESULTS: We found that PDPCs expressed the mesenchymal stem cell markers CD73, CD90, and CD105 and the pluripotent markers, octamer-binding transcription factor 4 and Nanog, but not sex-determining region Y-box 2 or Rex1. Periosteum-derived progenitor cells expressed human leukocyte antigen-ABC but did not express human leukocyte antigen-DR or the costimulatory molecules CD80 and CD86. Differentiated IPCs expressed pancreatic hormones (insulin, glucagon, somatostatin, and glucose transporter 2), hormone processing, and secretion molecules (prohormone convertase-1 and convertase-2, Kir6.2), and pancreatic transcription factors (neurogenin 3, pancreatic and duodenal homeobox 1, sex-determining region Y-box 17). When IPCs were stimulated with glucose in vitro, insulin secretion was elevated. Transplantation of IPCs under the kidney capsules of diabetic mice improved hyperglycemia and glucose tolerance. Human insulin was detected in the serum and kidney sections of mice transplanted with IPCs differentiated from PDPCs. CONCLUSION: These results suggest that IPCs differentiated from PDPCs might be an alternative source of ß cells for treating diabetes.


Asunto(s)
Hiperglucemia/terapia , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/metabolismo , Insulina/biosíntesis , Trasplante de Islotes Pancreáticos/métodos , Células Madre Adultas/citología , Células Madre Adultas/metabolismo , Animales , Glucemia/metabolismo , Diferenciación Celular , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/terapia , Femenino , Xenoinjertos , Humanos , Hiperglucemia/sangre , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos NOD , Ratones SCID , Periostio/citología
16.
Int J Oral Sci ; 6(4): 227-32, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25012869

RESUMEN

The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n=60) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (n=10) was filled with phosphate buffered saline (PBS); Group 2 (n=10) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3 (n=20) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (n=20) was incubated with E. faecalis for 3 weeks and then obturated with OrthoMTA-PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.


Asunto(s)
Compuestos de Aluminio/uso terapéutico , Compuestos de Calcio/uso terapéutico , Cavidad Pulpar/microbiología , Dentina/microbiología , Enterococcus faecalis/ultraestructura , Óxidos/uso terapéutico , Materiales de Obturación del Conducto Radicular/uso terapéutico , Silicatos/uso terapéutico , Calcificación Fisiológica/fisiología , Cristalización , Combinación de Medicamentos , Humanos , Metilmetacrilatos/uso terapéutico , Microscopía Electrónica de Rastreo , Obturación del Conducto Radicular/métodos , Preparación del Conducto Radicular/instrumentación , Factores de Tiempo , Cemento de Óxido de Zinc-Eugenol/uso terapéutico
17.
J Endod ; 40(3): 417-22, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24565663

RESUMEN

INTRODUCTION: Micro-computed tomography (MCT) shows detailed root canal morphology that is not seen with traditional tooth clearing. However, alternative image reformatting techniques in MCT involving 2-dimensional (2D) minimum intensity projection (MinIP) and 3-dimensional (3D) volume-rendering reconstruction have not been directly compared with clearing. The aim was to compare alternative image reformatting techniques in MCT with tooth clearing on the mesiobuccal (MB) root of maxillary first molars. METHODS: Eighteen maxillary first molar MB roots were scanned, and 2D MinIP and 3D volume-rendered images were reconstructed. Subsequently, the same MB roots were processed by traditional tooth clearing. Images from 2D, 3D, 2D + 3D, and clearing techniques were assessed by 4 endodontists to classify canal configuration and to identify fine anatomic structures such as accessory canals, intercanal communications, and loops. RESULTS: All image reformatting techniques in MCT showed detailed configurations and numerous fine structures, such that none were classified as simple type I or II canals; several were classified as types III and IV according to Weine classification or types IV, V, and VI according to Vertucci; and most were nonclassifiable because of their complexity. The clearing images showed less detail, few fine structures, and numerous type I canals. Classification of canal configuration was in 100% intraobserver agreement for all 18 roots visualized by any of the image reformatting techniques in MCT but for only 4 roots (22.2%) classified according to Weine and 6 (33.3%) classified according to Vertucci, when using the clearing technique. CONCLUSIONS: The combination of 2D MinIP and 3D volume-rendered images showed the most detailed canal morphology and fine anatomic structures.


Asunto(s)
Cavidad Pulpar/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Preparación del Conducto Radicular/métodos , Microtomografía por Rayos X/métodos , Adulto , Anciano , Carbono , Colorantes , Técnica de Descalcificación , Cavidad Pulpar/anatomía & histología , Humanos , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Imagenología Tridimensional/métodos , Imagenología Tridimensional/estadística & datos numéricos , Maxilar , Persona de Mediana Edad , Diente Molar/anatomía & histología , Diente Molar/diagnóstico por imagen , Ápice del Diente/anatomía & histología , Ápice del Diente/diagnóstico por imagen , Cuello del Diente/anatomía & histología , Cuello del Diente/diagnóstico por imagen , Microtomografía por Rayos X/estadística & datos numéricos
18.
J Endod ; 39(12): 1625-9, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24238461

RESUMEN

INTRODUCTION: The aggregation of mixed bacterial flora into sessile biofilms on root canal surfaces can be one of the causes of persistent apical periodontitis. The aim of this study was to evaluate the antibacterial efficacy of human ß-defensin-3 (HBD3) peptide on multispecies biofilms by using confocal laser scanning microscopy. METHODS: Actinomyces naeslundii, Lactobacillus salivarius, Streptococcus mutans, and Enterococcus faecalis were cultured in a peptone-yeast-glucose broth, and their culture suspensions were combined in equal proportions. The mixed bacteria were inoculated on sterile coverslips placed into the wells of tissue culture plates to permit the formation of mixed species biofilm. After incubation for 3 weeks, the samples were treated for 24 hours with saline (control), saturated calcium hydroxide solution (CH), 2% chlorhexidine solution (CHX), and 50 µg/mL HBD3 solution. A commercial biofilm/viability assay kit was used to assess cell viability and analyze the 3-dimensional architecture of biofilms. The percentage of dead cells was determined from the ratio of biovolumes for the red subpopulation and the total biofilm. RESULTS: Three medication groups showed a significant reduction of biovolume within the biofilms compared with the control group (P < .001). The HBD3-treated biofilms had a higher percentage of dead cells than the other medication groups (P < .05). The CH and CHX groups showed higher levels of bactericidal activity than saline (P < .05), and there was no significant difference between the 2 groups (P > .05). CONCLUSIONS: HBD3 peptide exhibited more antibacterial activity against mature multispecies biofilms in vitro than either CH or CHX.


Asunto(s)
Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , beta-Defensinas/farmacología , Actinomyces/efectos de los fármacos , Antiinfecciosos Locales/farmacología , Técnicas Bacteriológicas , Hidróxido de Calcio/farmacología , Clorhexidina/análogos & derivados , Clorhexidina/farmacología , Técnicas de Cocultivo , Colorantes , Enterococcus faecalis/efectos de los fármacos , Colorantes Fluorescentes , Humanos , Imagenología Tridimensional/métodos , Lactobacillus/efectos de los fármacos , Ensayo de Materiales , Viabilidad Microbiana/efectos de los fármacos , Microscopía Confocal , Compuestos Orgánicos , Propidio , Streptococcus mutans/efectos de los fármacos , Factores de Tiempo
19.
J Endod ; 39(9): 1136-40, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23953286

RESUMEN

INTRODUCTION: The aim of this study was to investigate the bacterial community profile of intracanal microbiota in primary and persistent endodontic infections associated with asymptomatic chronic apical periodontitis by using GS-FLX Titanium pyrosequencing. The null hypothesis was that there is no difference in diversity of overall bacterial community profiles between primary and persistent infections. METHODS: Pyrosequencing analysis from 10 untreated and 8 root-filled samples was conducted. RESULTS: Analysis from 18 samples yielded total of 124,767 16S rRNA gene sequences (with a mean of 6932 reads per sample) that were taxonomically assigned into 803 operational taxonomic units (3% distinction), 148 genera, and 10 phyla including unclassified. Bacteroidetes was the most abundant phylum in both primary and persistent infections. There were no significant differences in bacterial diversity between the 2 infection groups (P > .05). The bacterial community profile that was based on dendrogram showed that bacterial population in both infections was not significantly different in their structure and composition (P > .05). CONCLUSIONS: The present pyrosequencing study demonstrates that persistent infections have as diverse bacterial community as primary infections.


Asunto(s)
Bacterias/clasificación , Cavidad Pulpar/microbiología , Enfermedades de la Pulpa Dental/microbiología , Periodontitis Periapical/microbiología , Actinobacteria/clasificación , Adulto , Anciano , Enfermedades Asintomáticas , Bacteroidetes/clasificación , Fusobacterias/clasificación , Fusobacterium/clasificación , Bacterias Anaerobias Gramnegativas/clasificación , Bacterias Gramnegativas/clasificación , Humanos , Consorcios Microbianos , Persona de Mediana Edad , Prevotella/clasificación , Propionibacterium/clasificación , Proteobacteria/clasificación , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisis , Análisis de Secuencia de ADN , Spirochaetales/clasificación , Adulto Joven
20.
J Biosci Bioeng ; 113(6): 771-7, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22425523

RESUMEN

Mesenchymal stem cells (MSCs) are capable of crossing germinative layer borders and are obtainable in high numbers via in vitro cultures. Therefore, many researchers have searched for diverse sources of MSCs. Recently the generation of glucose-responsive insulin-producing cells (IPCs) from MSCs has shown immense potential for the treatment of type 1 diabetes mellitus (T1DM) due to a lack of pancreas donors. In this study, we compared the growth potency of four kinds of MSCs derived from bone marrow, Wharton's jelly, adipose tissue, and the periosteum. In addition, in vitro differentiation of these MSCs into IPCs was also investigated. After 2weeks of IPCs differentiation, we compared the expression of the insulin gene and protein using RT-qPCR and immunofluorescence staining. Only IPCs derived from periosteum-derived progenitor cells (PDPCs) showed a response to glucose concentration. Glucose stimulated insulin secretion was conclusive evidence of the potential functionality of IPCs. Therefore, PDPCs are a promising alternative stem cell source for IPCs differentiation.


Asunto(s)
Diferenciación Celular/fisiología , Glucosa/metabolismo , Insulina/metabolismo , Células Madre Mesenquimatosas/fisiología , Diabetes Mellitus Tipo 1/terapia , Insulina/biosíntesis , Secreción de Insulina , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/fisiología , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo
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