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

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
BMC Oral Health ; 24(1): 492, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664749

RESUMEN

OBJECTIVES: this study aims to compare the clinical outcomes of traditional and digital crown extension guides in the aesthetic restoration of anterior teeth. Additionally, the study will analyze the differences in the results of various digital crown extension guides in anterior aesthetic restorations. METHODS: Sixty-two patients who required aesthetic restoration of their anterior teeth were selected for this study. The patients had a total of 230 anterior teeth and were randomly divided into three groups: a control group of 22 cases who received diagnostic wax-up with pressure film, an experimental group 1 of 20 cases who received 3D printed digital models with pressure film, and an experimental group 2 of 20 patients who received digital dual-positioning guides. The control group had a total of 84 anterior teeth, experimental group 1 had 72 anterior teeth, and experimental group 2 had 74 anterior teeth. The study compared three methods for fabricating crown extension guides: the control group used the diagnostic wax-up plus compression film method, while experimental group 1 used compression film on 3D printed models and experimental group 2 used 3D printed digital dual-positioning crown extension guides. After the crown lengthening surgery, the control group patients wore DMG resin temporary crown material for gingival contouring, while the experimental group patients wore 3D printed resin temporary crowns for the same purpose. The patients were followed up in the outpatient clinic after wearing temporary crowns for 1 month, 3 months, and 6 months, respectively. The clinical results were evaluated in terms of marginal fit, red aesthetic index, and white aesthetic index. RESULTS: Based on the statistical analysis, the experimental group required significantly fewer follow-up visits and less time for guide design and fabrication compared to the control group. Additionally, the surgical time for the experimental group was significantly shorter than that of the control group. During the postoperative period between the 1st and 3rd month, the PES index scores for the marginal gingival level, proximal, and distal mesiodistal gingival papillae of the experimental group showed a trend of superiority over those of the control group. By the 6th month, the marginal gingival level exhibited a significant difference between the experimental and control groups. The experimental group demonstrated superior results to the control group in terms of shape, contour, and volume of the teeth, color, surface texture, and transparency of the restorations, and features during the 1st and 3rd postoperative months. In the 6th month, the comparative results indicated that the experimental group continued to exhibit superior outcomes to the control group in terms of the shape, color, surface texture, and transparency of the restorations, as well as the characteristics of the teeth. Additionally, the experimental group demonstrated significantly fewer gingival alterations than the control group at 1 month, 3 months, and 6 months post-procedure, with this difference being statistically significant. Furthermore, the combination of 3D printing technology and restorative techniques was utilized, resulting in consistent patient satisfaction. CONCLUSION: Digitalisation plays an important role in anterior aesthetic restorations. The use of digital technology to manage the entire process of anterior cosmetic restorations can improve restorative results, reduce the number of follow-up appointments, shorten consultation time, and achieve better patient satisfaction.


Asunto(s)
Coronas , Estética Dental , Sonrisa , Humanos , Femenino , Masculino , Adulto , Incisivo , Impresión Tridimensional , Tecnología Digital , Diseño de Prótesis Dental , Alargamiento de Corona/métodos , Adulto Joven , Persona de Mediana Edad , Diseño Asistido por Computadora
2.
Int Wound J ; 21(3): e14804, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38385817

RESUMEN

The process of wound healing in the dental pulp is characterized by intricate interplay of signalling cascades, cellular responses, and extracellular matrix (ECM). The objective of this research was to examine the intricate interaction between signalling cascades, cellular responses, and extracellular matrix (ECM) dynamics that comprise the wound healing process of dental pulp. We conducted a controlled laboratory analysis of transcriptomic landscape of dental pulp tissues, including both healthy and inflamed samples, utilizing single-cell RNA sequencing. We identified significant change in cellular composition under carious conditions by analysing samples from 50 patients. Specifically, the proportion of immune cells increased from 25% to 40%, while the proportion of fibroblasts decreased from 20% to 10%. A transition towards ECM remodelling and fibrosis was indicated by this change. In addition, substantial increase inexpression of critical genes including COL1A1, FN1, IL-1B, IL-6 and TNC was detected, indicating that the extracellular matrix (ECM) was actively remodelled and that a robust inflammatory response was present, both of which are vital for tissue repair. Increased cell-cell interactions among B cells, plasma cells, macrophages and MSCs, and fibroblasts were highlighted in our study, demonstrating the intricate cellular dynamics that occur in response to dental pulp injury. The knowledge gained regarding the cellular and molecular processes underlying pulp wound healing contributed to the advancement of knowledge regarding pulp pathology and regeneration. Moreover, it established a foundation for creation of targeted therapeutic interventions that seek to maximize pulp repair and regeneration. This study represented noteworthy achievement in the field of dental surgery, establishing a solid groundwork for subsequent investigations into regenerative medicine, wound healing, and dental tissue restoration.


Asunto(s)
Pulpa Dental , Perfilación de la Expresión Génica , Humanos , Estado de Salud , Fibroblastos , Análisis de Secuencia de ARN
3.
Oral Dis ; 2023 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-37246926

RESUMEN

OBJECTIVES: The aim of this study was to explore the potential role of zinc-finger homeodomain transcription factor (TCF8) in osteoclastogenesis and inflammation during periodontitis. MATERIALS AND METHODS: Rats with periodontitis were induced via Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS) injection. The recombinant lentivirus delivering short hairpin RNA (shRNA) against TCF8 was used to downregulate TCF8 in vivo. Alveolar bone loss in rats was determined by micro-computed tomography (Micro-CT). Typical pathological changes, periodontal tissue inflammation, and osteoclastogenesis were evaluated via histological analyses. The RAW264.7-derived osteoclasts were induced by RANKL stimulation. TCF8 downregulation in vitro was achieved by lentivirus infection. The osteoclast differentiation and inflammatory signaling in RANKL-induced cells were measured via immunofluorescence methods and molecular biology approaches. RESULTS: Porphyromonas gingivalis-lipopolysaccharide induced rats exhibited overexpressed TCF8 in their periodontal tissues, while TCF8 knockdown attenuated the bone loss, tissue inflammation, and osteoclastogenesis in LPS-induced rats. Besides, TCF8 silencing inhibited RANKL-induced osteoclast differentiation in RAW264.7 cells, as evidenced by the reduced numbers of TRAP-positive osteoclasts, less formation of F-actin rings, and downregulated expressions of osteoclast-specific markers. It also exerted an inhibitory effect on the NF-κB signaling in RANKL-induced cells via blocking NF-κB p65 phosphorylation and nuclear translocation. CONCLUSIONS: TCF8 silencing inhibited alveolar bone loss, osteoclast differentiation, and inflammation in periodontitis.

4.
Int J Mol Sci ; 24(23)2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-38069279

RESUMEN

Tumors are a major public health issue of concern to humans, seriously threatening the safety of people's lives and property. With the increasing demand for early and accurate diagnosis and efficient treatment of tumors, noninvasive optical imaging (including fluorescence imaging and photoacoustic imaging) and tumor synergistic therapies (phototherapy synergistic with chemotherapy, phototherapy synergistic with immunotherapy, etc.) have received increasing attention. In particular, light in the near-infrared second region (NIR-II) has triggered great research interest due to its penetration depth, minimal tissue autofluorescence, and reduced tissue absorption and scattering. Nanomaterials with many advantages, such as high brightness, great photostability, tunable photophysical properties, and excellent biosafety offer unlimited possibilities and are being investigated for NIR-II tumor imaging-guided synergistic oncotherapy. In recent years, many researchers have tried various approaches to investigate nanomaterials, including gold nanomaterials, two-dimensional materials, metal sulfide oxides, polymers, carbon nanomaterials, NIR-II dyes, and other nanomaterials for tumor diagnostic and therapeutic integrated nanoplatform construction. In this paper, the application of multifunctional nanomaterials in tumor NIR-II imaging and collaborative therapy in the past three years is briefly reviewed, and the current research status is summarized and prospected, with a view to contributing to future tumor therapy.


Asunto(s)
Nanopartículas , Nanoestructuras , Neoplasias , Humanos , Fototerapia/métodos , Polímeros/uso terapéutico , Nanoestructuras/uso terapéutico , Neoplasias/terapia , Neoplasias/tratamiento farmacológico , Imagen Óptica , Nanomedicina Teranóstica/métodos
5.
Lasers Med Sci ; 37(8): 3249-3258, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35854018

RESUMEN

The disinfection of root canal through minimally invasive access cavity remains questionable. This in vitro study compared the effectiveness of three disinfection measures including conventional irrigation, ultrasonic assisted irrigation, and erbium:yttrium-aluminum-garnet (Er:YAG) laser assisted irrigation through conventionally or minimally invasive access. Sixty-six extracted maxillary first molars were randomly divided into group 1 conventionally invasive access group (CIA) and group 2 computer-guided minimally invasive access group (MIA). Each group was further randomly divided into three subgroups, (A) conventional irrigation (CI), (B) passive ultrasonic agitation (PUI), and (C) Er:YAG laser activated irrigation (LAI). Enterococcus faecalis (E. faecalis) infection model was established inside all root canals after instrumentation was performed up to ProTaper Universal F2. After various disinfection methods, microbial samples were collected from root canals by paper tip method and cultured, and colony forming units (CFU) values of each sample were calculated. Then the root canals were enlarged to the size of F3, after which dentin debris was collected from the F3 file. After dilution and culturing, the CFU value was calculated for each group. Two-way analysis of variance (ANOVA) was performed to test the interaction. The results revealed a significant antagonism (F = 3.394, P = 0.043). The bacterial CFU counts of group B and group C were significantly less than that of group A (P < 0.05), and there was no significant difference between group B and C (P > 0.05). Additionally, group 2A was better than group 1A (P < 0.05); there was no significant difference between group 1B and group 2B, group 1C and group 2C (P > 0.05). Comparison of the bacterial CFU counts in dentin debris after disinfection, the results revealed a significant antagonism (F = 7.224, P = 0.002), and group C had the least. The disinfection effect of Er:YAG laser or ultrasonic assisted computer-guided minimally invasive access is similar to conventionally invasive access, and Er:YAG laser is better than ultrasonic in removing bacteria from dentinal tubules and is easy to operate, which is more suitable for minimally invasive root canal treatment.


Asunto(s)
Láseres de Estado Sólido , Cavidad Pulpar , Desinfección/métodos , Enterococcus faecalis , Erbio , Láseres de Estado Sólido/uso terapéutico , Irrigantes del Conducto Radicular/farmacología , Preparación del Conducto Radicular/métodos , Hipoclorito de Sodio/farmacología , Ultrasonido
6.
J Mater Sci Mater Med ; 32(9): 115, 2021 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-34455518

RESUMEN

Caries and dental erosion are common oral diseases. Traditional treatments involve the mechanical removal of decay and filling but these methods are not suitable for cases involving large-scale enamel erosion, such as hypoplasia. To develop a noninvasive treatment, promoting remineralisation in the early stage of caries is of considerable clinical significance. Therefore, biomimetic mineralisation is an ideal approach for restoring enamel. Biomimetic mineralisation forms a new mineral layer that is tightly attached to the surface of the enamel. This review details the state-of-art achievements on the application of amelogenin and non-amelogenin, amorphous calcium phosphate, ions flow and other techniques in the biomimetic mineralisation of enamel. The ultimate goal of this review was to shed light on the requirements for enamel biomineralisation. Hence, herein, we summarise two strategies of biological minimisation systems for in situ enamel restoration inspired by amelogenesis that have been developed in recent years and compare their advantages and disadvantages.


Asunto(s)
Materiales Biomiméticos , Esmalte Dental/efectos de los fármacos , Restauración Dental Permanente , Amelogénesis/efectos de los fármacos , Amelogenina/química , Amelogenina/farmacología , Animales , Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Biomimética/métodos , Calcificación Fisiológica/efectos de los fármacos , Calcificación Fisiológica/fisiología , Fosfatos de Calcio/química , Fosfatos de Calcio/farmacología , Esmalte Dental/química , Restauración Dental Permanente/instrumentación , Restauración Dental Permanente/métodos , Humanos
7.
Small ; 16(9): e1901819, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31379136

RESUMEN

Heterostructure rough spindle-knot microfibers (HRSFs) are fabricated via a flexible parallel-nozzle microfluidic method. In this method, the bioinspired HRSF with a roughness gradient between spindle-knots and joints, can be manufactured in large-scale, and with which the size of the spindle-knots and joints can be precisely adjusted by regulating flow rates. The HRSFs, fabricated with chitosan and calcium alginate, have strong mechanical properties and corrosion resistance in acid environment (pH = 5) and alkaline environment (pH = 9), respectively. More attractively, under controlled treatment conditions, the morphology of the spindle-knots on the HRSFs can be effectively managed by changing the composite content of calcium chloride in the fluid. During the water collection process, tiny droplets of moisture can be captured on the surface of the HRSFs, subsequently, the droplets can coalesce and be transported from joint to spindle-knot sections. It is demonstrated that the surface morphology of spindle-knots directly influences the water collection efficiency, where a higher roughness gradient generates higher water collection efficiency. This parallel-nozzle microfluidic technology provides a low-cost and flexible method to manufacture high biocompatibility bioinspired rough spindle-knot microfibers, which has many potential applications in large-scale water collection, sustained drug release, and directional water collection.


Asunto(s)
Materiales Biocompatibles , Microfluídica , Agua , Alginatos/química , Materiales Biocompatibles/aislamiento & purificación , Calcio/química , Agua/química
8.
Faraday Discuss ; 217: 8-33, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31094388

RESUMEN

This introduction provides a historical context for the development of ion spectroscopy over the past half century by following the evolution of experimental methods to the present state-of-the-art. Rather than attempt a comprehensive review, we focus on how early work on small ions, carried out with fluorescence, direct absorption, and photoelectron spectroscopy, evolved into powerful technologies that can now address complex chemical problems ranging from catalysis to biophysics. One of these developments is the incorporation of cooling and temperature control to enable the general application of "messenger tagging" vibrational spectroscopy, first carried out using ionized supersonic jets and then with buffer gas cooling in radiofrequency ion traps. Some key advances in the application of time-resolved pump-probe techniques to follow ultrafast dynamics are also discussed, as are significant benchmarks in the refinement of ion mobility to allow spectroscopic investigation of large biopolymers with well-defined shapes. We close with a few remarks on challenges and opportunities to explore molecular level mechanics that drive macroscopic behavior.


Asunto(s)
Fenómenos Astronómicos , Biopolímeros/análisis , Física , Análisis Espectral/tendencias , Biología , Análisis Espectral/instrumentación
9.
Mediators Inflamm ; 2016: 8467849, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26884650

RESUMEN

Periodontitis is a kind of chronic inflammatory disease that affects the tooth-supporting tissues. ET-1 is related to periodontitis and involved in the regulation of cytokines, but the mechanisms remain unclear. The aim of this study is to investigate how ET-1 affects proinflammatory cytokine expression and differentiation in human periodontal ligament stem cells (PDLSCs). PDLSCs were isolated from the periodontal ligament tissues of periodontitis patients and then treated with ET-1 (1, 10, or 100 nM) for 12 h, 24 h, or 72 h. The osteogenic potential of PDLSCs was tested using ALP staining. TNF-α, IL-1ß, and IL-6 levels were evaluated by ELISA and western blot. Runx2, OCN, and COL1 mRNA and western levels were detected by RT-PCR and western blot, respectively. To examine the signaling pathways and molecular mechanisms involved in ET-1-mediated cytokine expression and osteogenic differentiation, ETR pathway, MAPKs pathway, Wnt/ß-catenin pathway, and Wnt/Ca(2+) pathway were detected by RT-PCR and western blot, respectively. ET-1 promoted differentiation of PDLSCs into osteoblasts by increasing secretion of TNF-α, IL-1ß, and IL-6 in a dose- and time-dependent manner. ET-1 also increased expression of Runx2, OCN, and COL1. ET-1 promotes differentiation of PDLSCs into osteoblasts through ETR, MAPK, and Wnt/ß-catenin signaling pathways under inflammatory microenvironment.


Asunto(s)
Endotelina-1/farmacología , Osteoblastos/citología , Ligamento Periodontal/citología , Células Madre/citología , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Humanos , Interleucina-6/metabolismo , Osteoblastos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Células Madre/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo , Vía de Señalización Wnt
10.
Mol Pharm ; 12(1): 232-9, 2015 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-25418453

RESUMEN

Lung cancer is the major cause of cancer related lethality worldwide, and metastasis to distant organs is the pivotal cause of death for the vast majority of lung cancer patients. Accumulated evidence indicates that lung cancer stem-like cells (CSLCs) play important roles in metastagenesis, and these circulating CSLCs may be important targets to inhibit the subsequent metastasis. The present study was aimed at establishing CSLC-targeting polylactic acid (PLA) encapsulated docetaxel nanoparticles for antimetastatic therapy. Cyclic binding peptides were screened on CSLCs in vitro and the peptide CVKTPAQSC exhibiting high specific binding ability to pulmonary adenocarcinoma tissue was subsequently conjugated to the nanoparticles loaded with docetaxel (NDTX). Antimetastatic effect of CSLC-targeting nanoparticles loaded with docetaxel (TNDTX) was evaluated in a nude mouse model of liver metastasis. Results showed that, in the absence of targeting peptide, NDTX hardly exhibited any antimetastatic effect. However, TNDTX treatment significantly decreased the metastatic tumor area in the nude mouse liver. Histopathological and serological results also confirmed the antimetastatic efficacy of TNDTX. To our knowledge, this is the first report on establishing a CSLC-based strategy for lung cancer metastatic treatment, and we hope this will offer a potential therapeutic approach for management of metastatic lung cancer.


Asunto(s)
Antineoplásicos/administración & dosificación , Ácido Láctico/química , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Células Neoplásicas Circulantes/efectos de los fármacos , Polímeros/química , Taxoides/administración & dosificación , Antígeno AC133 , Animales , Antígenos CD/metabolismo , Peso Corporal , Línea Celular Tumoral , Docetaxel , Portadores de Fármacos , Femenino , Glicoproteínas/metabolismo , Hígado/metabolismo , Neoplasias Hepáticas/patología , Neoplasias Pulmonares/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Nanomedicina , Nanopartículas/química , Metástasis de la Neoplasia , Péptidos/química , Péptidos/metabolismo , Poliésteres
11.
Int J Mol Sci ; 16(10): 23867-80, 2015 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-26473831

RESUMEN

Synthetic amphiphilic polymers have been established as potentially efficient agents to combat widespread deadly infections involving antibiotic resistant superbugs. Incorporation of poly(ethylene glycol) (PEG) side chains into amphiphilic copolymers can reduce their hemolytic activity while maintaining high antibacterial activity. Our study found that the incorporation of PEG has substantially different effects on the hemolytic and antibacterial activities of copolymers depending on structural variations in the positions of cationic centers relative to hydrophobic groups. The PEG side chains dramatically reduced the hemolytic activities in copolymers with hydrophobic hexyl and cationic groups on the same repeating unit. However, in case of terpolymers with cationic and lipophilic groups placed on separate repeating units, the presence of PEG has significantly lower effect on hemolytic activities of these copolymers. PEGylated terpolymers displayed substantially lower activity against Staphylococcus aureus (S. aureus) than Escherichia coli (E. coli) suggesting the deterring effect of S. aureus' peptidoglycan cell wall against the penetration of PEGylated polymers. Time-kill studies confirmed the bactericidal activity of these copolymers and a 5 log reduction in E. coli colony forming units was observed within 2 h of polymer treatment.


Asunto(s)
Acrilatos/farmacología , Antibacterianos/farmacología , Escherichia coli/efectos de los fármacos , Polietilenglicoles/farmacología , Staphylococcus aureus/efectos de los fármacos , Acrilatos/química , Antibacterianos/química , Cationes/química , Pared Celular/efectos de los fármacos , Farmacorresistencia Bacteriana , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Interacciones Hidrofóbicas e Hidrofílicas , Pruebas de Sensibilidad Microbiana , Polietilenglicoles/química , Polímeros/química , Polímeros/farmacología , Ácidos Polimetacrílicos/química , Tensoactivos/química , Tensoactivos/farmacología
12.
Dent Mater J ; 43(2): 200-206, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38296510

RESUMEN

To investigate the mechanism underlying high acid resistance of enamel after erbium laser etching. Forty-five premolars were collected and assigned to three groups. A 4×4×1 mm enamel sample was prepared, the left side was the control side, the right side was the treated side, which was treated with different surface treatments, including 35% phosphoric acid etching, Er:YAG laser etching, and Er,Cr:YSGG laser etching. The hydroxyapatite crystal size on the enamel surface of the samples was observed. The contents of Ca, P, O, F, Cl, C, Mg were detected. The crystallinity of the hydroxyapatite crystal was analyzed. After erbium laser etching, the enamel surface had high hydroxyapatite crystal size, beneficial content of chemical elements and crystallinity. The morphological and composition changes of crystals in the enamel surface after erbium laser etching may be one of the crucial mechanisms underlying the enhancement of acid resistance of enamel after erbium laser etching.


Asunto(s)
Recubrimiento Dental Adhesivo , Láseres de Estado Sólido , Erbio/farmacología , Grabado Ácido Dental , Esmalte Dental , Hidroxiapatitas/farmacología
13.
BMC Oral Health ; 13: 8, 2013 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-23331491

RESUMEN

BACKGROUND: The need to obtain information on the dental prosthetic treatment needs (DPTNs) of inpatients with schizophrenia is unrecognized. This study aims to assess the DPTNs of this population and investigate the association between these needs and related factors. METHODS: The results of an oral health survey involving 1,103 schizophrenic adult inpatients in a long-term care institution in Taiwan were used. Chi-square tests and multiple logistic analyses were used to measure the independent effects of the characteristics of each subject on their DPTNs. RESULTS: Of the subjects, 805 (73.0%) were men and 298 (27.0%) were women. The mean age was 50.8 years. A total of 414 (37.5%) required fixed prosthesis, whereas 700 (63.5%) needed removable prosthesis. Multivariate analyses show that fixed prosthesis is associated with age only after adjusting for other potential independent variables. Older subjects who had a lower educational attainment or a longer length of stay required removable prosthesis. CONCLUSIONS: The findings of this study show that the DPTNs of schizophrenic inpatients are not being met. Therefore, a special approach to the dental prosthetic treatment of these patients should be developed.


Asunto(s)
Atención Dental para Enfermos Crónicos , Prótesis Dental/estadística & datos numéricos , Necesidades y Demandas de Servicios de Salud/estadística & datos numéricos , Pacientes Internos , Esquizofrenia , Adulto , Anciano , Análisis de Varianza , Distribución de Chi-Cuadrado , Intervalos de Confianza , Estudios Transversales , Femenino , Hospitales Psiquiátricos , Humanos , Modelos Logísticos , Cuidados a Largo Plazo , Masculino , Persona de Mediana Edad , Taiwán , Adulto Joven
14.
J Mech Behav Biomed Mater ; 138: 105658, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36610283

RESUMEN

This work reports the first in vitro study on the in-situ biodegradation behaviour and the evolution of fixation strength of Zn-Cu alloy wires in a simulated sternum closure environment. Zn-Cu wires were used to reapproximate the partial bisected sternum models, and their fixation effect was compared with traditional surgical grade 316 L stainless steel (SS) wires in terms of fixation rigidity, critical load, first/ultimate failure characteristics. The metal sutures were then immersed in Hank's balanced salt solution for 12 weeks immersion period, and their corrosion behaviours assessed. Zn-Cu wires showed similar fixation rigidity at 70.89 ± 6.97 N/mm as SS, but the critical load, first failure and ultimate failure characteristics were inferior to SS. The key challenges that limited the fixation effect of the Zn-Cu wires were poor mechanical strength, short elastic region, and strain softening behaviours, which resulted in poor load-bearing capabilities and reduced the knot security of the sutures. The in-situ biodegradation of the Zn-Cu suture was accompanied by the early onset of localised corrosion within the twisted knot and the section located next to the incision line. Crevice corrosion and strain-induced corrosion were the dominant mechanisms in the observed localised corrosion. The localised corrosion on the Zn-Cu sutures did not lead to a significant shift in fixation rigidity, critical load and the first failure characteristics. The findings suggest that the Zn-based biodegradable metallic wires could be a promising sternum closure suture material once the limitations in mechanical characteristics are addressed.


Asunto(s)
Esternón , Técnicas de Sutura , Esternón/cirugía , Hilos Ortopédicos , Suturas , Acero Inoxidable , Aleaciones/farmacología , Corrosión , Zinc , Ensayo de Materiales
15.
Acta Biomater ; 167: 593-607, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37369266

RESUMEN

A zinc-nutrient element alloy (Zn-1.0Cu-0.5Ca) was developed into subcuticular absorbable staples (SAS) as a robust alternative to the commercially available poly(l-lactide-co-glycolide) (PLGA) SAS for the first time. The fixation properties of the Zn SAS were measured via pull-out tests and in-situ lap-shear pull-out test comparatively against the PLGA SAS. The Zn SAS exhibited fixation force of 18.9±0.2 N, which was over three times higher than that of PLGA SAS (5.5±0.1 N). The Zn SAS was used to close incision wounds in a SD rat model for biodegradability and biocompatibility characterisation at 1, 4 and 12 weeks. The Zn SAS showed uniform degradation behaviour after in vivo implantation at the average rate of 198±54, 112±28, and 70±24 µm/y after 1, 4, and 12 weeks, which reduced the fixation force to 16.8±1.1 N, 15.4±0.9 N, 12.7±0.7 N, respectively. These findings showed the potential of the Zn SAS for the closure of heavy loading and slowing healing tissues. The Zn SAS enabled successful closure and healing of the incision wound, similar to the PLGA staples. However, the slow long-term degradation rate of the Zn SAS may lead to unnecessary implant retention. In addition, the alloy SAS resulted in higher local foreign body responses due to their stiffness. Reducing the implant cross-section profile and applying low stiffness and a corrosion-accelerating coating are suggested as possible approaches to reduce post-service implant retention and improve the biocompatibility of the Zn SAS. STATEMENT OF SIGNIFICANCE: This work reports the fabrication of the first metallic subcuticular absorbable staples (SAS) made from ZnCuCa alloy for skin wound closure applications. The Zn-based SAS were characterised in vitro and in vivo (SD rat model) for biodegradability, fixation properties, biocompatibility and inflammatory responses, which were compared against the commercially available PLGA-based SAS. The Zn-based SAS provided a secure attachment of the full-thickness wounds on SD rats and allowed successful healing during the 12-week service period. In addition, the in vitro results showed that the Zn-based SAS provided more than three times higher fixation strength than the commercial PLGA, indicating the potential of the Zn-based SAS for load-bearing wound closure application.


Asunto(s)
Cicatrización de Heridas , Zinc , Animales , Ratas , Ratas Sprague-Dawley , Suturas , Aleaciones/farmacología , Implantes Absorbibles , Ensayo de Materiales
16.
ACS Biomater Sci Eng ; 9(3): 1261-1273, 2023 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-36808972

RESUMEN

As a representative of the biodegradable iron (Fe)-manganese (Mn) alloys, Fe35Mn has been investigated as a promising biodegradable metal biomaterial for orthopedic applications. However, its slow degradation rate, though better than pure Fe, and poor bioactivity are concerns that retard its clinical applications. Akermanite (Ca2MgSi2O7, Ake) is a silicate-based bioceramic, showing desirable degradability and bioactivity for bone repair. In the present work, Fe35Mn/Ake composites were prepared via a powder metallurgy route. The effect of different contents of Ake (0, 10, 30, 50 vol %) on the microstructure, mechanical properties, degradation, and biocompatibility of the composites was investigated. The ceramic phases were found to be evenly distributed in the metal matrix. The Ake reacted with Fe35Mn and generated CaFeSiO4 during sintering. The addition of Ake increased the relative density of pure Fe35Mn from ∼90 to ∼94-97%. The compressive yield strength (CYS) and elastic modulus (Ec) increased with increasing Ake, with Fe35Mn/50Ake exhibiting the highest CYS of ∼403 MPa and Ec of ∼18 GPa. However, the ductility decreased at higher Ake concentrations (30 and 50%). Microhardness also showed an increasing trend with the addition of Ake. Electrochemical measurements indicated that higher concentrations of Ake (30 and 50%) could potentially increase the corrosion rate of Fe35Mn from ∼0.25 to ∼0.39 mm/year. However, all of the compositions tested did not show measurable weight loss after immersion in simulated body fluid (SBF) for 4 weeks, attributed to the use of prealloyed raw material, high sintered density of the fabricated composites, and the formation of a dense Ca-, P-, and O-rich layer on the surface. Human osteoblasts on Fe35Mn/Ake composites showed increasing viability with increasing Ake content, indicating improved in vitro biocompatibility. These preliminary results suggest that Fe35Mn/Ake can be a potential material for biodegradable bone implant applications, particularly Fe35Mn/30Ake, if the slow corrosion of the composite can be addressed.


Asunto(s)
Materiales Biocompatibles , Cerámica , Humanos , Ensayo de Materiales , Cerámica/química , Aleaciones
17.
Environ Pollut ; 333: 121933, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37277069

RESUMEN

Microplastic (MP) pollution is a critical environmental issue. Dandelions could be used as a biomonitor of environmental pollution. However, the ecotoxicology of MPs in dandelions remains unclear. Therefore, the toxic effects of polyethylene (PE), polystyrene (PS), and polypropylene (PP) at concentrations of 0, 10, 100, and 1000 mg L-1 on the germination and early seedling growth of dandelion were investigated. PS and PP inhibited seed germination and decreased root length and biomass while promoting membrane lipid peroxidation, increasing O2•-, H2O2, SP, and proline contents, and enhancing the activities of SOD, POD, and CAT. Principal component analysis (PCA) and membership function value (MFV) analysis indicated that PS and PP could be more harmful than PE in dandelion, especially at 1000 mg L-1. In addition, according to the integrated biological response (IBRv2) index analysis, O2•-, CAT, and proline were sensitive biomarkers of dandelion contamination by MPs. Here we provide evidence that dandelion has the potential to be a biomonitor to assess the phytotoxicity of MPs pollution, especially PS with high toxicity. Meanwhile, we believe that if dandelion is to be used as a biomonitor for MPs, attention should also be paid to the practical safety of dandelion.


Asunto(s)
Alcaloides , Taraxacum , Contaminantes Químicos del Agua , Microplásticos/toxicidad , Plásticos/toxicidad , Peróxido de Hidrógeno , Poliestirenos/toxicidad , Polietileno , Alcaloides/análisis , Polipropilenos , Contaminantes Químicos del Agua/análisis
18.
Front Immunol ; 14: 1179007, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37143646

RESUMEN

Periodontal disease is an infectious disease that affects many people worldwide. Disease progression destroys the alveolar bone and causes tooth loss. We have previously shown that alymphoplasia (aly/aly) mice harboring a loss-of-function mutation in the map3k14 gene, which is involved in p100 to p52 processing of the alternative NF-κB pathway, exhibited mild osteopetrosis due to decreased number of osteoclasts, suggesting the alternative NF-κB pathway as a potential drug target for the amelioration of bone disease. In the present study, wild-type (WT) and aly/aly mice were subjected to silk ligation to establish a periodontitis model. Alveolar bone resorption was suppressed in aly/aly mice by decreased numbers of osteoclasts in the alveolar bone in comparison to WT mice. Furthermore, the expression of receptor activator of NF-κB ligand (RANKL) and TNFα (cytokines involved in osteoclast induction in periligative gingival tissue) was decreased. When primary osteoblasts (POBs) and bone marrow cells (BMCs) derived from WT and aly/aly mice were prepared and co-cultured, osteoclasts were induced from WT-derived BMCs, regardless of the origin of the POBs, but hardly formed from aly/aly mouse-derived BMCs. Furthermore, the local administration of an NIK inhibitor, Cpd33, inhibited osteoclast formation and thereby inhibited alveolar bone resorption in the periodontitis model. Therefore, the NIK-mediated NF-κB alternative pathway can be a therapeutic target for periodontal disease.


Asunto(s)
Enfermedades Óseas Metabólicas , Resorción Ósea , Enfermedades Periodontales , Periodontitis , Ratones , Animales , FN-kappa B/metabolismo , Inflamación
19.
J Formos Med Assoc ; 111(4): 214-9, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22526210

RESUMEN

BACKGROUND/PURPOSE: There is little comparative research evidence to support the claim that there is disparity in dental care between inpatients with schizophrenia and the disabled people or the general population. This study aimed to investigate whether schizophrenia inpatients had poorer dental care and worse oral health than the disabled people and the general population, respectively. METHODS: An oral health survey was conducted in a specific-psychiatric long-term care institution in Taiwan in 2006. The results of this survey were compared with the findings of oral health investigations of the disabled people or the general population in Taiwan using proportion test and t-test. RESULTS: This study used decayed, missing, and filled teeth index (DMFT) to describe the condition of dental caries. Compared with the disabled people, schizophrenia inpatients aged 19 to 44 years had a lower subjects' filling rate of DMFT index (FI) and a higher caries experience, but schizophrenia inpatients aged 45 or more had a lower mean number of DMFT. Compared with the general population, schizophrenia inpatients had higher caries experience, mean number of DMFT, percentage edentulous, and community periodontal index and lower FI and number of remaining tooth among various gender or age groups. CONCLUSION: In Taiwan, inpatients with schizophrenia have a lower FI than the disabled people and a worse overall oral health status than the general population.


Asunto(s)
Caries Dental/epidemiología , Personas con Discapacidad/estadística & datos numéricos , Pacientes Internos/estadística & datos numéricos , Salud Bucal , Esquizofrenia/epidemiología , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Índice CPO , Caries Dental/complicaciones , Femenino , Encuestas Epidemiológicas , Disparidades en Atención de Salud , Hospitales Psiquiátricos , Humanos , Cuidados a Largo Plazo , Masculino , Persona de Mediana Edad , Higiene Bucal , Vigilancia de la Población , Taiwán/epidemiología , Adulto Joven
20.
Biomaterials ; 280: 121301, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34922270

RESUMEN

The need for the development of load-bearing, absorbable wound closure devices is driving the research for novel materials that possess both good biodegradability and superior mechanical characteristics. Biodegradable metals (BMs), namely: magnesium (Mg), zinc (Zn) and iron (Fe), which are currently being investigated for absorbable vascular stent and orthopaedic implant applications, are slowly gaining research interest for the fabrication of wound closure devices. The current review presents an overview of the traditional and novel BM-based intracutaneous and transcutaneous wound closure devices, and identifies Zn as a promising substitute for the traditional materials used in the fabrication of absorbable load-bearing sutures, internal staples, and subcuticular staples. In order to further strengthen Zn to be used in highly stressed situations, nutrient elements (NEs), including calcium (Ca), Mg, Fe, and copper (Cu), are identified as promising alloying elements for the strengthening of Zn-based wound closure device material that simultaneously provide potential therapeutic benefit to the wound healing process during implant biodegradation process. The influence of NEs on the fundamental characteristics of biodegradable Zn are reviewed and critically assessed with regard to the mechanical properties and biodegradability requirements of different wound closure devices. The opportunities and challenges in the development of Zn-based wound closure device materials are presented to inspire future research on this rapidly growing field.


Asunto(s)
Aleaciones , Zinc , Implantes Absorbibles , Aleaciones/uso terapéutico , Materiales Biocompatibles/uso terapéutico , Magnesio , Ensayo de Materiales , Nutrientes
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA