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1.
Small ; : e2311033, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459643

RESUMO

The re-tear rate of rotator cuff tears (RCT) after surgical repair is high, especially in aged patients with chronic tears. Senescent tendon stem cells (s-TSCs) generally exist in aged and chronically torn rotator cuff tendons and are closely associated with impaired tendon-to-bone healing results. The present study found a positive feedback cross-talk between s-TSCs and macrophages. The conditioned medium (CM) from s-STCs can promote macrophage polarization mainly toward the M1 phenotype, whose CM reciprocally accelerated further s-TSC senescence. Additional healthy tendon stem-cells derived exosomes (h-TSC-Exos) can break this positive feedback cross-talk by skewing macrophage polarization from the M1 phenotype to the M2 phenotype, attenuating s-TSCs senescence. S-TSC senescence acceleration or attenuation effects induced by M1 or M2 macrophages are associated with the inhibition or activation of the bone morphogenetic protein 4 signaling pathway following RNA sequencing analysis. Using an aged-chronic rotator cuff tear rat model, it is found that h-TSC-Exos can shift the microenvironment in the tendon-to-bone interface from a pro-inflammatory to an anti-inflammatory type at the acute postoperative stage and improve the tendon-to-bone healing results, which are associated with the rejuvenated s-TSCs. Therefore, this study proposed a potential strategy to improve the healing of aged chronic RCT.

2.
J Pineal Res ; 76(1): e12924, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37941528

RESUMO

Osteoporotic bone defects, a severe complication of osteoporosis, are distinguished by a delayed bone healing process and poor repair quality. While bone marrow-derived mesenchymal stem cells (BMMSCs) are the primary origin of bone-forming osteoblasts, their mitochondrial function is impaired, leading to inadequate bone regeneration in osteoporotic patients. Melatonin is well-known for its antioxidant properties and regulation on bone metabolism. The present study postulated that melatonin has the potential to enhance the repair of osteoporotic bone defects by restoring the mitochondrial function of BMMSCs. In vitro administration of melatonin at varying concentrations (0.01, 1, and 100 µM) demonstrated a significant dose-dependent improvement in the mitochondrial function of BMMSCs obtained from ovariectomized rats (OVX-BMMSCs), as indicated by an elevation in mitochondrial membrane potential, adenosine triphosphate synthesis and expression of mitochondrial respiratory chain factors. Melatonin reduced the level of mitochondrial superoxide by activating the silent information regulator type 1 (SIRT1) and its downstream antioxidant enzymes, particularly superoxide dismutase 2 (SOD2). The protective effects of melatonin were found to be nullified upon silencing of Sirt1 or Sod2, underscoring the crucial role of the SIRT1-SOD2 axis in the melatonin-induced enhancement of mitochondrial energy metabolism in OVX-BMMSCs. To achieve a sustained and localized release of melatonin, silk fibroin scaffolds loaded with melatonin (SF@MT) were fabricated. The study involved the surgical creation of bilateral femur defects in OVX rats, followed by the implantation of SF@MT scaffolds. The results indicated that the application of melatonin partially restored the mitochondrial energy metabolism and osteogenic differentiation of OVX-BMMSCs by reinstating mitochondrial redox homeostasis. These findings suggest that the localized administration of melatonin through bone implants holds potential as a therapeutic approach for addressing osteoporotic bone defects.


Assuntos
Melatonina , Células-Tronco Mesenquimais , Osteoporose , Humanos , Ratos , Animais , Osteogênese , Melatonina/metabolismo , Sirtuína 1/metabolismo , Antioxidantes/uso terapêutico , Medula Óssea/metabolismo , Osteoporose/tratamento farmacológico , Diferenciação Celular , Mitocôndrias/metabolismo , Células Cultivadas
3.
Eur Spine J ; 33(4): 1490-1497, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38062266

RESUMO

BACKGROUND: Vertebral augmentation, such as vertebroplasty (VP) or kyphoplasty (KP), has been utilized for decades to treat OVCFs; however, the precise impact of this procedure on reducing mortality risk remains a topic of controversy. This study aimed to explore the potential protective effects of vertebral augmentation on mortality in patients with osteoporotic vertebral compression fractures (OVCFs) using a large-scale meta-analysis. MATERIALS AND METHODS: Cochrane Library, Embase, MEDLINE, PubMed and Web of Science databases were employed for literature exploration until May 2023. The hazard ratios (HRs) and 95% confidence intervals (CIs) were utilized as a summary statistic via random-effect models. Statistical analysis was executed using Review Manager 5.3 software. RESULTS: After rigorous screening, a total of five studies with substantial sample sizes were included in the quantitative meta-analysis. The total number of participants included in the study was an 2,421,178, comprising of 42,934 cases of vertebral augmentation and 1,991,244 instances of non-operative management. The surgical intervention was found to be significantly associated with an 18% reduction in the risk of mortality (HR 0.82; 95% CI 0.78, 0.85). Subgroup analysis revealed a remarkable 71% reduction in mortality risk following surgical intervention during short-term follow-up (HR 0.29; 95% CI 0.26, 0.32). Furthermore, KP exhibited a superior and more credible decrease in the risk of mortality when compared to VP treatment. CONCLUSIONS: Based on a comprehensive analysis of large samples, vertebral augmentation has been shown to significantly reduce the mortality risk associated with OVCFs, particularly in the early stages following fractures. Furthermore, it has been demonstrated that KP is more reliable and effective than VP in terms of mitigating mortality risk.


Assuntos
Fraturas por Compressão , Cifoplastia , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Vertebroplastia , Humanos , Cifoplastia/métodos , Fraturas por Compressão/cirurgia , Fraturas da Coluna Vertebral/etiologia , Fraturas por Osteoporose/cirurgia , Vertebroplastia/métodos , Resultado do Tratamento
4.
Nanotechnology ; 34(15)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36734530

RESUMO

Flexible electronic and optoelectronic devices are highly desirable for various emerging applications, such as human-computer interfaces, wearable medical electronics, flexible display, etc. Layered two-dimensional (2D) material is one of the most promising types of materials to develop flexible devices due to its atomically thin thickness, which gives it excellent flexibility and mechanical endurance. However, the 2D material devices fabricated on flexible substrate inevitably suffer from mechanical deformation, which can severely affect device performances, resulting in function degradation and even failure. In this work, we propose a strain insensitive flexible photodetector based on MoS2/MoTe2heterostructure on polyimide substrate, which provides a feasible approach to cancel unpredicted impacts of strain on the device performances. Specifically, the MoS2/MoTe2heterostructure is deposited with 4 electrodes to form three independent devices of MoS2FET, MoTe2FET and MoS2/MoTe2heterojunction. Among them, the MoS2/MoTe2heterojunction is used as the photodetector, while the MoS2FET is used as a strain gauge to calibrate the photo detection result. Such configuration is enabled by the Schottky barrier formed between the electrodes and the MoS2flake, which leads to obvious and negligible photo response of MoS2/MoTe2heterojunction and MoS2FET, respectively, under low source-drain bias (ex. 10 mV). The experimental results show that the proposed mechanism can not only calibrate the photo response to cancel strain effect, but also successfully differentiate the wavelength (with fixed power) or power (with fixed wavelength) of light illumination.

5.
Apoptosis ; 27(9-10): 762-777, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35779185

RESUMO

Bone marrow mesenchymal stem cells (BMSCs) have strong regenerative potential and show good application prospects for treating clinical diseases. However, in the process of BMSC transplantation for treating ischemic and hypoxic diseases, BMSCs have high rates of apoptosis in the hypoxic microenvironment of transplantation, which significantly affects the transplantation efficacy. Our previous studies have confirmed the key role of long non-coding RNA Tmem235 (LncRNA Tmem235) in the process of hypoxia-induced BMSC apoptosis and its downstream regulatory mechanism, but the upstream mechanism by which hypoxia regulates LncRNA Tmem235 expression to induce BMSC apoptosis is still unclear. Under hypoxic conditions, we found that the level of LncRNA Tmem235 promoter histone H3 lysine 27 trimethylation modification (H3K27me3) was significantly increased by CHIP-qPCR. Moreover, H3K27me3 cooperated with LncRNA Tmem235 promoter DNA methylation to inhibit the expression of LncRNA Tmem235 and promote apoptosis of BMSCs. To study the mechanism of hypoxia-induced modification of LncRNA Tmem235 promoter H3K27me3 in the hypoxia model of BMSCs, we detected the expression of H3K27 methylase and histone demethylase and found that only histone methylase enhancer of zeste homolog 2 (EZH2) expression was significantly upregulated. Knockdown of EZH2 significantly decreased the level of H3K27me3 modification in the LncRNA Tmem235 promoter. The EZH2 promoter region contains a hypoxia-responsive element (HRE) that interacts with hypoxia-inducible factor-1alpha (HIF-1α), which is overexpressed under hypoxic conditions, thereby promoting its overexpression. In summary, hypoxia promotes the modification of the LncRNA Tmem235 promoter H3K27me3 through the HIF-1α/EZH2 signaling axis, inhibits the expression of LncRNA Tmem235, and leads to hypoxic apoptosis of BMSCs. Our findings improve the regulatory mechanism of LncRNA Tmem235 during hypoxic apoptosis of BMSCs and provide a more complete theoretical pathway for targeting LncRNA to inhibit hypoxic apoptosis of BMSCs.


Assuntos
Células-Tronco Mesenquimais , RNA Longo não Codificante , Apoptose/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Lisina/genética , Lisina/metabolismo , Células-Tronco Mesenquimais/metabolismo , Regiões Promotoras Genéticas , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
6.
J Pineal Res ; 73(2): e12815, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35726138

RESUMO

Recent evidence indicates that the mitochondrial functions of chondrocytes are impaired in the pathogenesis of osteoarthritis (OA). Melatonin can attenuate cartilage degradation through its antioxidant functions. This study aims to investigate whether melatonin could rescue the impaired mitochondrial functions of OA chondrocytes and protect cartilage metabolism. OA chondrocytes showed a compromised matrix synthesis capacity associated with mitochondrial dysfunction and aberrant oxidative stress. In vitro treatments with melatonin promoted the expression of cartilage extracellular matrix (ECM) components, improved adenosine triphosphate production, and attenuated mitochondrial oxidative stress. Mechanistically, either silencing of SOD2 or inhibition of SIRT1 abolished the protective effects of melatonin on mitochondrial functions and ECM synthesis. To achieve a sustained release effect, a melatonin-laden drug delivery system (DDS) was developed and intra-articular injection with DDS successfully improved cartilage matrix degeneration in a posttraumatic rat OA model. These findings demonstrate that melatonin-mediated recharge of mitochondria to rescue the mitochondrial functions of chondrocytes represents a promising therapeutic strategy to protect cartilage from OA.


Assuntos
Cartilagem Articular , Melatonina , Osteoartrite , Animais , Cartilagem Articular/patologia , Condrócitos/metabolismo , Preparações de Ação Retardada/metabolismo , Preparações de Ação Retardada/farmacologia , Preparações de Ação Retardada/uso terapêutico , Homeostase , Melatonina/metabolismo , Mitocôndrias/metabolismo , Osteoartrite/metabolismo , Ratos
7.
J Nanobiotechnology ; 20(1): 303, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35761235

RESUMO

Loss of extracellular matrix (ECM) of cartilage due to oxidative stress injury is one of the main characteristics of osteoarthritis (OA). As a bioactive molecule derived from the traditional Chinese Burdock, arctiin exerts robust antioxidant properties to modulate redox balance. However, the potential therapeutic effects of arctiin on OA and the underlying mechanisms involved are still unknown. Based on the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) tool, Burdock-extracted small molecule arctiin was identified as a potential anti-arthritic component. In vitro, treatment using arctiin rescued the interleukin (IL)-1ß-induced activation of proteinases and promoted the cartilage ECM synthesis in human chondrocytes. In vivo, intraperitoneal injection of arctiin ameliorated cartilage erosion and encountered subchondral bone sclerosis in the post-traumatic OA mice. Transcriptome sequencing uncovered that arctiin-enhanced cartilage matrix deposition was associated with restricted oxidative stress. Mechanistically, inhibition of nuclear factor erythroid 2-related factor 2 (NRF2) abolished arctiin-mediated anti-oxidative and anti-arthritic functions. To further broaden the application prospects, a gellan gum (GG)-based bioactive gel (GG-CD@ARC) encapsulated with arctiin was made to achieve long-term and sustained drug release. Intra-articular injection of GG-CD@ARC counteracted cartilage degeneration in the severe (12 weeks) OA mice model. These findings indicate that arctiin may be a promising anti-arthritic agent. Furthermore, GG-modified bioactive glue loaded with arctiin provides a unique strategy for treating moderate to severe OA.


Assuntos
Antioxidantes , Osteoartrite , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Condrócitos , Furanos , Glucosídeos/farmacologia , Glucosídeos/uso terapêutico , Camundongos , Osteoartrite/tratamento farmacológico
8.
Int J Mol Sci ; 23(12)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35743287

RESUMO

Oxygen-generating materials have been used in several tissue engineering applications; however, their application as in situ oxygen supply within bioprinted constructs has not been deeply studied. In this study, two oxygen-generating materials, sodium percarbonate (SPO) and calcium peroxide (CPO), were studied for their oxygen release kinetics under a 0.1% O2 condition. In addition, a novel cell-culture-insert setup was used to evaluate the effects of SPO and CPO on the viability of skeletal muscle cells under the same hypoxic condition. Results showed that SPO had a burst oxygen release, while CPO had a more stable oxygen release than SPO. Both SPO and CPO reduced cell viability when used alone. The addition of catalase in SPO and CPO increased the oxygen release rate, as well as improving the viability of skeletal muscle cells; however, CPO still showed cytotoxicity with catalase. Additionally, the utilization of 1 mg/mL SPO and 20 U catalase in a hydrogel for bioprinting significantly enhanced the cell viability under the hypoxic condition. Moreover, bioprinted muscle constructs could further differentiate into elongated myotubes when transferring back to the normoxic condition. This work provides an excellent in vitro model to test oxygen-generating materials and further discover their applications in bioprinting, where they represent promising avenues to overcome the challenge of oxygen shortage in bioprinted constructs before their complete vascularization.


Assuntos
Bioimpressão , Engenharia Tecidual , Carbonatos , Catalase , Humanos , Hipóxia , Cinética , Oxigênio , Peróxidos , Impressão Tridimensional , Engenharia Tecidual/métodos , Alicerces Teciduais
9.
Aging Clin Exp Res ; 33(12): 3161-3172, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33913118

RESUMO

OBJECTIVES: Dementia is a common mental disorder that affects the life quality in elders. Recently, emerging studies reported the negative impacts of dementia on prognosis after hip surgeries. However, the integrated and reliable role of dementia in hip surgery is not illustrated. METHODS: We searched the relevant literatures before June 2020 and extracted the data that met the inclusion criteria. The influence of dementia on postoperative walking ability, complications including infection, cardiovascular complications, hip dislocation, delirium, and respiratory complications, and survival rate at different periods were evaluated. Qualitative and quantitative analysis were conducted using Review Manager Version 5.3. RESULTS: The meta-analysis enrolled a total of 30 studies with 1,037,049 patients. The pooled results revealed that there were significant negative impacts of dementia on the recovery of postoperative walking ability, postoperative infection, hip dislocation, delirium and respiratory complications and mortality at different periods. CONCLUSIONS: Dementia is a crucial risk factor for the poor prognosis after hip fracture surgery. Therefore, when making clinical strategies for hip fracture patients with dementia, countermeasures for possible complications should be generated.


Assuntos
Demência , Fraturas do Quadril , Idoso , Fraturas do Quadril/cirurgia , Humanos , Complicações Pós-Operatórias , Prognóstico , Fatores de Risco
10.
J Cell Mol Med ; 24(20): 11972-11983, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32896108

RESUMO

Osteolysis around the prosthesis and subsequent aseptic loosening are the main causes of prosthesis failure. Inflammation due to wear particles and osteoclast activation are the key factors in osteolysis and are also potential targets for the treatment of osteolysis. However, it is not clear whether puerarin can inhibit chronic inflammation and alleviate osteolysis. In this study, we investigated the effect of puerarin on Ti particle-induced inflammatory osteolysis in vivo in rat femoral models and in vitro in receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast activation models. Our in vivo results showed that puerarin significantly inhibited Ti particle-induced osteolysis and the expression of matrix metallopeptidase 9 (MMP-9), nuclear factor of activated T cells 1 (NFATc1), tumour necrosis factor (TNF)-α and interleukin (IL)-6. In vitro, puerarin prevented RANKL-induced osteoclast differentiation, bone resorption and F-actin ring formation in a concentration-dependent manner. Furthermore, puerarin decreased the phosphorylation of p65 and prevented p65 moving from the cytoplasm to the nucleus. Puerarin also reduced the expression of osteoclast-specific factors and inhibited the inflammatory response. In conclusion, our study proves that puerarin can block the NF-κB signalling pathway to inhibit osteoclast activation and inflammatory processes, which provides a new direction for the treatment of osteolysis-related diseases.


Assuntos
Isoflavonas/farmacologia , NF-kappa B/metabolismo , Osteogênese , Osteólise/induzido quimicamente , Ligante RANK/farmacologia , Transdução de Sinais , Titânio/efeitos adversos , Actinas/metabolismo , Animais , Reabsorção Óssea/complicações , Reabsorção Óssea/patologia , Reabsorção Óssea/prevenção & controle , Citocinas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Isoflavonas/química , Isoflavonas/uso terapêutico , Masculino , Camundongos , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteogênese/efeitos dos fármacos , Osteólise/complicações , Osteólise/patologia , Células RAW 264.7 , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
11.
Nat Mater ; 18(5): 482-488, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30886399

RESUMO

In two-dimensional (2D) systems, high mobility is typically achieved in low-carrier-density semiconductors and semimetals. Here, we discover that the nanobelts of Weyl semimetal NbAs maintain a high mobility even in the presence of a high sheet carrier density. We develop a growth scheme to synthesize single crystalline NbAs nanobelts with tunable Fermi levels. Owing to a large surface-to-bulk ratio, we argue that a 2D surface state gives rise to the high sheet carrier density, even though the bulk Fermi level is located near the Weyl nodes. A surface sheet conductance up to 5-100 S per □ is realized, exceeding that of conventional 2D electron gases, quasi-2D metal films, and topological insulator surface states. Corroborated by theory, we attribute the origin of the ultrahigh conductance to the disorder-tolerant Fermi arcs. The evidenced low-dissipation property of Fermi arcs has implications for both fundamental study and potential electronic applications.

12.
BMC Neurol ; 20(1): 143, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32312321

RESUMO

BACKGROUND: This meta-analysis was designed to investigate the long-term efficacy and safety between cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) in treating cervical disc degenerative diseases (CDDDs). METHODS: Literature search was performed on Pubmed, Embase, Cochrane Library, and Web of Science before Jan 2019. Surgical details, clinical outcomes, range of motion (ROM), complications, and reoperation rates between CDA and ACDF groups were compared and analyzed. A fixed- or random-effects model was applied based on different heterogeneity. STATA (Version 11.0) software was used to perform data analysis. RESULTS: A total of 13 randomized controlled trial studies with more than 60 months of follow-up (mean 83.1 months) were enrolled in this meta-analysis. Pool results indicated that the CDA group exhibited significantly better outcomes in clinical scores (odds ratio [OR] = 1.54, 95% confidence interval [CI]: 1.15-2.08, p = 0.004) and preservation of ROM (mean difference = 1.77, 95% CI: 1.60-1.95, p < 0.001) than the ACDF group. Meanwhile, the incidence of adjacent segment disease (ASD) (OR = 0.51, 95% CI: 0.35-0.76, p = 0.001) and occurrence of reoperation (OR = 0.41, 95% CI: 0.25-0.69, p = 0.001) were lower in the CDA group than in the ACDF group. CONCLUSIONS: At long-term follow-up, CDA showed better efficacy in terms of clinical outcomes, ROM, ASD, and reoperation than ACDF for treating CDDDs. However, our results require further validation in large-sample and high-quality studies.


Assuntos
Vértebras Cervicais/cirurgia , Degeneração do Disco Intervertebral/cirurgia , Procedimentos Ortopédicos , Humanos , Procedimentos Ortopédicos/efeitos adversos , Procedimentos Ortopédicos/métodos , Procedimentos Ortopédicos/estatística & dados numéricos , Complicações Pós-Operatórias , Ensaios Clínicos Controlados Aleatórios como Assunto , Reoperação , Resultado do Tratamento
13.
BMC Oral Health ; 20(1): 176, 2020 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-32586315

RESUMO

BACKGROUND: Mechanical plaque removal has been commonly accepted to be the basis for periodontal treatment. This study aims to compare the effectiveness of ultrasonic and manual subgingival scaling at different initial probing pocket depths (PPD) in periodontal treatment. METHODS: English-language databases (PubMed, Cochrane Central Register of Controlled Trials, EMBASE, Medline, and ClinicalTrials.gov, by January, 2019) were searched. Weighted mean differences in primary outcomes, PPD and clinical attachment loss (CAL) reduction, were estimated by random effects model. Secondary outcomes, bleeding on probing (BOP), gingival recession (GR), and post-scaling residual dental calculus, were analyzed by comparing the results of each study. The quality of RCTs was appraised with the Cochrane Collaboration risk of bias tool. The GRADE approach was used to assess quality of evidence. RESULTS: Ten randomized controlled trials were included out of 1434 identified. Initial PPD and follow-up periods formed subgroups. For 3-months follow-up: (1) too few shallow initial pocket studies available to draw a conclusion; (2) the heterogeneity of medium depth studies was so high that could not be merged to draw a conclusion; (3) deep pocket studies showed no statistical differences in PPD and CAL reduction between ultrasonic and manual groups. For 6-months follow-up: (1) too few shallow initial PPD studies to draw a conclusion; (2) at medium pocket depth, PPD reduction showed manual subgingival scaling better than ultrasound. No statistical differences were observed in CAL reduction between the two approaches; (3) for deep initial PPD studies, both PPD and CAL reduction showed manual subgingival scaling better. GR results indicated no statistical differences at medium and deep initial pocket studies between the two methods. BOP results showed more reduction at deep pocket depths with manual subgingival scaling. No conclusion could be drawn about residual dental calculus. CONCLUSION: When initial PPD was 4-6 mm, PPD reduction proved manual subgingival scaling was superior, but CAL results showed no statistical differences between the two means. When initial PPD was ≥6 mm, PPD and CAL reductions suggested that manual subgingival scaling was superior.


Assuntos
Raspagem Dentária , Periodontite/terapia , Ultrassom , Humanos , Bolsa Periodontal , Projetos Piloto , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
Int J Mol Sci ; 20(9)2019 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-31027323

RESUMO

Poly(methyl methacrylate) (PMMA) bone cements have been widely used in clinical practices. In order to enhance PMMA's imaging performance to facilitate surgical procedures, a supplementation of radiopaque agent is needed. However, PMMA bone cements are still facing problems of loosening and bacterial infection. In this study, a multifunctional coating to simultaneously encapsulate drug and prevent the infection of radiopaque agent has been developed. Barium sulfate (BaSO4), a common radiopaque agent, is used as a substrate material. We successfully fabricated porous BaSO4 microparticles, then modified with hexakis-(6-iodo-6-deoxy)-alpha-cyclodextrin (I-CD) and silver (Ag) to obtain porous BaSO4@PDA/I-CD/Ag microparticles. The porous nature and presence of PDA coating and I-CD on the surface of microparticles result in efficient loading and release of drugs such as protein. Meanwhile, the radiopacity of BaSO4@PDA/I-CD/Ag microparticles is enhanced by this multifunctional coating containing Ba, I and Ag. PMMA bone cements containing BaSO4@PDA/I-CD/Ag microparticles show 99% antibacterial rate against both Staphylococcus aureus (S. aureus) and Escherichia Coli (E. coli), yet without apparently affecting its biocompatibility. Together, this multifunctional coating possessing enhanced radiopacity, controlled drug delivery capability and exceptional antibacterial performance, may be a new way to modify radiopaque agents for bone cements.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Sulfato de Bário/química , Cimentos Ósseos/química , Polimetil Metacrilato/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
15.
Int J Mol Sci ; 19(6)2018 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-29895809

RESUMO

Poly (methyl methacrylate) (PMMA)-based bone cements are the most commonly used injectable orthopedic materials due to their excellent injectability and mechanical properties. However, their poor biocompatibility and excessive stiffness may cause complications such as aseptic implant loosening and stress shielding. In this study, we aimed to develop a new type of partially biodegradable composite bone cement by incorporating magnesium (Mg) microspheres, known as "Mg sacrifices" (MgSs), in the PMMA matrix. Being sensitive to the physiological environment, the MgSs in PMMA could gradually degrade to produce bioactive Mg ions and, meanwhile, result in an interconnected macroporous structure within the cement matrix. The mechanical properties, solidification, and biocompatibility, both in vitro and in vivo, of PMMA⁻Mg bone cement were characterized. Interestingly, the incorporation of Mg microspheres did not markedly affect the mechanical strength of bone cement. However, the maximum temperature upon setting of bone cement decreased. This partially biodegradable composite bone cement showed good biocompatibility in vitro. In the in vivo study, considerable bony ingrowth occurred in the pores upon MgS degradation. Together, the findings from this study indicate that such partially biodegradable PMMA⁻Mg composite may be ideal bone cement for minimally invasive orthopedic surgeries such as vertebroplasty and kyphoplasty.


Assuntos
Cimentos Ósseos/química , Polimetil Metacrilato/química , Magnésio/química , Osseointegração/fisiologia , Temperatura
16.
J Cell Mol Med ; 20(8): 1542-9, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27061332

RESUMO

Recent studies have suggested that platelet-rich plasma (PRP) injections are an effective way to retard intervertebral disc degeneration, but the mechanism of action is unclear. Activated platelets release some growth factors, such as transforming growth factor-ß1 (TGF-ß1), which positively modulate the extracellular matrix of nucleus pulposus cells. The purpose of this study was to explore the mechanism underlying the PRP-mediated inhibition of intervertebral disc degeneration. In an in vitro study, we found that the proliferation of nucleus pulposus cells was greatly enhanced with 2.5% PRP treatment. The TGF-ß1 concentration was much higher after PRP treatment. PRP administration effectively increased the collagen II, aggrecan and sox-9 mRNA levels and decreased collagen X levels. However, Western blotting demonstrated that specifically inhibiting TGF-ß1 signalling could significantly prevent nucleus pulpous cellular expression of Smad2/3 and matrix protein. In a rabbit study, magnetic resonance imaging revealed significant recovery signal intensity in the intervertebral discs of the PRP injection group compared with the very low signal intensity in the control groups. Histologically, the PRP plus inhibitor injection group had significantly lower expression levels of Smad2/3 and collagen II than the PRP group. These results demonstrated that a high TGF-ß1 content in the platelets retarded disc degeneration in vitro and in vivo. Inhibiting the TGF-ß1/Smad2/3 pathway could prevent this recovery by inactivating Smad2/3 and down-regulating the extracellular matrix. Therefore, the TGF-ß1/Smad2/3 pathway might play a critical role in the ability of PRP to retard intervertebral disc degeneration.


Assuntos
Degeneração do Disco Intervertebral/metabolismo , Plasma Rico em Plaquetas/metabolismo , Transdução de Sinais , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Western Blotting , Proliferação de Células , Colágeno Tipo II/metabolismo , Ensaio de Imunoadsorção Enzimática , Regulação da Expressão Gênica , Imuno-Histoquímica , Degeneração do Disco Intervertebral/patologia , Imageamento por Ressonância Magnética , Núcleo Pulposo/patologia , Contagem de Plaquetas , Coelhos , Reação em Cadeia da Polimerase em Tempo Real
17.
Acta Radiol ; 55(8): 985-91, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24280137

RESUMO

BACKGROUND: Osteoporotic vertebral biconcave-shaped fractures are not commonly seen in clinical practice. Some articles have been published showing the outcome of vertebroplasty (PV) and balloon kyphoplasty (BKP), but few comparative studies have been performed. PURPOSE: To compare the effect and safety of PV and BKP in treating osteoporotic vertebral biconcave-shaped fractures. MATERIAL AND METHODS: In this retrospective comparative study, 38 patients with osteoporotic vertebral biconcave-shaped fractures were treated by PV, and 41 patients were treated by BKP from May 2005 to July 2011. The heights of the compromised vertebral body and the kyphotic angles were measured. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate pain and functional activity, respectively. The occurrence of refracture and cement leakage were determined, and the costs were recorded. RESULTS: The mean VAS and ODI scores significantly improved for both procedures at postsurgical measurements (P < 0.05), and the improvement sustained at the final follow-up. In both groups, there were no significant differences in terms of restoration of the anterior vertebral height and correction of the kyphotic deformity. However, BKP was more effective in restoring the middle vertebral height than PV. Cement leakages were observed in nine (23.7%) treated vertebral bodies in PV group and in three (7.4%) treated vertebral bodies in BKP group, which was a statistically significant difference (P < 0.05). There were four new osteoporotic vertebral fractures in the PV group and two in the BKP group during the follow-up period. The mean cost in the BKP group (6200 ± 122.1 USD) was higher than the PV group (2100 ± 112.5 USD) (P < 0.05). CONCLUSION: Both PV and BKP achieved similar improvements in pain and functional outcomes for the treatment of osteoporotic vertebral biconcave-shaped fractures. BKP had a significant advantage over PV in terms of the restoration of the middle vertebral height and fewer cement leakages than PV.


Assuntos
Fraturas por Osteoporose/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Vertebroplastia/métodos , Vertebroplastia/normas , Idoso , Feminino , Seguimentos , Humanos , Cifoplastia/métodos , Cifoplastia/normas , Masculino , Fraturas por Osteoporose/complicações , Fraturas por Osteoporose/diagnóstico por imagem , Dor/etiologia , Dor/prevenção & controle , Medição da Dor/métodos , Radiografia , Estudos Retrospectivos , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem , Resultado do Tratamento
18.
J Mater Sci Mater Med ; 25(7): 1709-19, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24659100

RESUMO

To prepare a bioactive bone substitute, which integrates biphasic calcium phosphate (BCP) and rhBMP-2/silk fibroin (SF) microsphere, and to evaluate its characteristics. Hydroxyapatite and ß-tricalcium phosphate were integrated with a ratio of 60­40%. RhBMP-2/SF (0.5 µg/1 mg) microsphere was prepared, and its rhBMP-2-release kinetics was assed. After joining pore-forming agent (Sodium chloride, NaCl), porous BCP/rhBMP-2/SF were manufactured, and its characteristics and bioactivity in vitro were evaluated. Mean diameter of rhBMP-2/SF microsphere was 398.7 ± 99.86 nm, with a loading rate of 4.53 ± 0.08%. RhBMP-2 was released in a dual-phase pattern, of which fast-release (nearly half of protein released) focused on the initial 3 days, and slow-release sustained more than 28 days. With the increase in concentration of NaCl, greater was porosity and pore size, but smaller mechanical strength of BCP/rhBMP-2/SF. Material with 150% (w/v) NaCl had an optimal performance, with a porosity of 78.83%, pore size of 293.25 ± 42.77µm and mechanical strength of 31.03 MPa. Proliferation of human placenta-derived mesenchymal stem cells (hPMSCs) on leaching extract medium was similar to the normal medium (P = 0.89), which was better than that on control group (P = 0.03). Activity of alkaline phosphatase on BCP/rhBMP-2/SF surface was higher than on pure BCP at each time point except at 1 day (P < 0.05). RhBMP-2 has a burst release on early times and a sustaining release on later times. BCP/rhBMP-2/SF with 150% (w/v) pore-forming agent has excellent porosity, pore size and mechanical strength. The biomaterial induces proliferation and differentiation hPMSCs effectively.


Assuntos
Proteína Morfogenética Óssea 2/química , Fosfatos de Cálcio/química , Fibroínas/química , Microesferas , Fator de Crescimento Transformador beta/química , Animais , Materiais Biocompatíveis/química , Bombyx , Osso e Ossos/metabolismo , Adesão Celular , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Durapatita/química , Feminino , Humanos , Cinética , Células-Tronco Mesenquimais/citologia , Microscopia Eletrônica de Varredura , Placenta/metabolismo , Porosidade , Gravidez , Proteínas Recombinantes/química , Cloreto de Sódio/química , Estresse Mecânico , Fatores de Tempo
19.
Pharmazie ; 69(8): 585-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25158568

RESUMO

This study was to investigate the physical and chemical compatibility of butorphanol with tramadol or fentanyl in 0.9% sodium chloride injections for patient controlled analgesia administration. The solutions were prepared in polyvinyl chloride (PVC) infusion bags and stored without protected from light exposure at room temperature (25 degrees C) or refrigerated (4 degrees C). Over a period of 168 hours, stabilities were determined by visual inspection, pH measurement, and high-pressure liquid chromatography (HPLC) assay of drug concentrations. At both temperatures, admixtures of butorphanol-tramadol and butorphanol-fentanyl were clear in appearance, and no color change or precipitation was observed during the study period. The maximum losses obtained were lower than 5% for the three drugs after 168 hours of storage. The results indicate that, at ambient or refrigerated storage conditions, the drug mixtures of butorphanol-tramadol and butorphanol-fentanyl in 0.9% sodium chloride injections were physically and chemically stable for at least 168 hours when stored in PVC syringes.


Assuntos
Analgesia Controlada pelo Paciente/métodos , Butorfanol/química , Fentanila/química , Entorpecentes/química , Tramadol/química , Butorfanol/administração & dosagem , Cromatografia Líquida de Alta Pressão , Combinação de Medicamentos , Incompatibilidade de Medicamentos , Estabilidade de Medicamentos , Fentanila/administração & dosagem , Indicadores e Reagentes , Infusões Intravenosas , Entorpecentes/administração & dosagem , Soluções Farmacêuticas , Tramadol/administração & dosagem
20.
Foods ; 13(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38672852

RESUMO

Rose tea is a type of flower tea in China's reprocessed tea category, which is divided into seven grades, including super flower, primary flower, flower bud, flower heart, yellow flower, scattered flower, and waste flower. Grading rose tea into distinct quality levels is a practice that is essential to boosting their competitive advantage. Manual grading is inefficient. We provide a lightweight model to advance rose tea grading automation. Firstly, four kinds of attention mechanisms were introduced into the backbone and compared. According to the experimental results, the Convolutional Block Attention Module (CBAM) was chosen in the end due to its ultimate capacity to enhance the overall detection performance of the model. Second, the lightweight module C2fGhost was utilized to change the original C2f module in the neck to lighten the network while maintaining detection performance. Finally, we used the SIoU loss in place of the CIoU loss to improve the boundary regression performance of the model. The results showed that the mAP, precision (P), recall (R), FPS, GFLOPs, and Params values of the proposed model were 86.16%, 89.77%, 83.01%, 166.58, 7.978, and 2.746 M, respectively. Compared with the original model, the mAP, P, and R values increased by 0.67%, 0.73%, and 0.64%, the GFLOPs and Params decreased by 0.88 and 0.411 M, respectively, and the speed was comparable. The model proposed in this study also performed better than other advanced detection models. It provides theoretical research and technical support for the intelligent grading of roses.

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