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1.
Small ; 18(30): e2202201, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35771091

RESUMO

Developing dynamic and highly sensitive methods for imaging M2-type tumor-associated macrophages (TAMs) is vital for monitoring the tumor progression and assessing the therapeutic efficacy. Here, the fabrication and application of rationally designed Er-based rare-earth nanoprobes for the targeted imaging of M2-type TAMs in glioblastoma (GBM) through the second near-infrared (NIR-II) fluorescence beyond 1500 nm is reported. The NIR-IIb fluorescence of Er-based rare-earth nanoparticles can be remarkably enhanced by optimizing their core-shell structures and the shell thickness, which allows for in vivo imaging under excitation by a 980 nm laser with the lowest power density (40 mW cm-2 ). These bright Er-based nanoparticles functionalized with M2pep polypeptide show notable targeting ability to M2-type macrophages, which has been well tested in both in vitro and in vivo experiments by their up-conversion (UC) fluorescence (540 nm) and down-shifting (DS) fluorescence (1525 nm), respectively. The targeting capability of these nanoprobes in vivo is also demonstrated by the overlap of immunofluorescence of M2-type TAMs and Arsenazo III staining of rare-earth ions in tumor tissue. It is envisioned that these nanoprobes can serve as a companion diagnostic tool to dynamically assess the progression and prognosis of GBM.


Assuntos
Glioblastoma , Metais Terras Raras , Nanopartículas , Glioblastoma/diagnóstico por imagem , Humanos , Raios Infravermelhos , Metais Terras Raras/química , Nanopartículas/química , Imagem Óptica , Macrófagos Associados a Tumor
2.
J Mater Sci Mater Med ; 29(6): 85, 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-29892835

RESUMO

Nitrogen doped graphene quantum dots (N-GQDs) were synthesized to explore and extend their potential applications in biomedical field. The hemocompatibility and cytotoxity of the obtained N-GQDs were primarily assessed at concentrations ranging from 10 to 100 µg/ml. From the results, it was found that the proliferation of rat Bone Mesenchymal Stem Cells (rBMSCs) was depressed to a certain extent after incubating with the high concentration (100 µg/ml) of N-GQDs. The nanoscale size and superior dispersibility endow N-GQDs with good cell permeability. Meanwhile, owing to their intrinsic photoluminescence characteristic, the N-GQDs can be used to label cells with high uniformity and light stability in absence of chemical dyes. More importantly, the up-regulated expression of alkaline phosphate (ALP), extracellular matrix, osteopontin (OPN) and osteocalcin (OCN) in rBMSCs cultured with N-GQDs, indicating N-GQDs have the abilities to promote rBMSCs osteogenic differentiation. This work would help give a new insight into the advantages of N-GQDs and pave the way for application of N-GQDs in regenerative medicine fields.


Assuntos
Grafite/química , Células-Tronco Mesenquimais/citologia , Nitrogênio/química , Osteogênese , Pontos Quânticos , Animais , Adesão Celular , Diferenciação Celular , Proliferação de Células , Imuno-Histoquímica , Teste de Materiais , Microscopia Eletrônica de Varredura , Nanotecnologia/métodos , Osteocalcina/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Medicina Regenerativa
3.
J Neural Eng ; 21(2)2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38588700

RESUMO

Objective. The instability of the EEG acquisition devices may lead to information loss in the channels or frequency bands of the collected EEG. This phenomenon may be ignored in available models, which leads to the overfitting and low generalization of the model.Approach. Multiple self-supervised learning tasks are introduced in the proposed model to enhance the generalization of EEG emotion recognition and reduce the overfitting problem to some extent. Firstly, channel masking and frequency masking are introduced to simulate the information loss in certain channels and frequency bands resulting from the instability of EEG, and two self-supervised learning-based feature reconstruction tasks combining masked graph autoencoders (GAE) are constructed to enhance the generalization of the shared encoder. Secondly, to take full advantage of the complementary information contained in these two self-supervised learning tasks to ensure the reliability of feature reconstruction, a weight sharing (WS) mechanism is introduced between the two graph decoders. Thirdly, an adaptive weight multi-task loss (AWML) strategy based on homoscedastic uncertainty is adopted to combine the supervised learning loss and the two self-supervised learning losses to enhance the performance further.Main results. Experimental results on SEED, SEED-V, and DEAP datasets demonstrate that: (i) Generally, the proposed model achieves higher averaged emotion classification accuracy than various baselines included in both subject-dependent and subject-independent scenarios. (ii) Each key module contributes to the performance enhancement of the proposed model. (iii) It achieves higher training efficiency, and significantly lower model size and computational complexity than the state-of-the-art (SOTA) multi-task-based model. (iv) The performances of the proposed model are less influenced by the key parameters.Significance. The introduction of the self-supervised learning task helps to enhance the generalization of the EEG emotion recognition model and eliminate overfitting to some extent, which can be modified to be applied in other EEG-based classification tasks.


Assuntos
Eletroencefalografia , Emoções , Aprendizado de Máquina Supervisionado , Aprendizado de Máquina Supervisionado/normas , Conjuntos de Dados como Assunto , Humanos
4.
ACS Nano ; 18(23): 15114-15129, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38798240

RESUMO

Implant-related secondary infections are a challenging clinical problem. Sonodynamic therapy (SDT) strategies are promising for secondary biofilm infections by nonsurgical therapy. However, the inefficiency of SDT in existing acoustic sensitization systems limits its application. Therefore, we take inspiration from popular metamaterials and propose the design idea of a metainterface heterostructure to improve SDT efficiency. The metainterfacial heterostructure is defined as a periodic arrangement of heterointerface monoclonal cells that amplify the intrinsic properties of the heterointerface. Herein, we develop a TiO2/Ti2O3/vertical graphene metainterface heterostructure film on titanium implants. This metainterface heterostructure exhibits extraordinary sonodynamic and acoustic-to-thermal conversion effects under low-intensity ultrasound. The modulation mechanisms of the metainterface for electron accumulation and separation are revealed. The synergistic sonodynamic/mild sonothermal therapy disrupts biofilm infections (antibacterial rates: 99.99% for Staphylococcus aureus, 99.54% for Escherichia coli), and the osseointegration ability of implants is significantly improved in in vivo tests. Such a metainterface heterostructure film lays the foundation for the metainterface of manipulating electron transport to enhance the catalytic performance and holding promise for addressing secondary biofilm infections.


Assuntos
Antibacterianos , Biofilmes , Escherichia coli , Staphylococcus aureus , Titânio , Terapia por Ultrassom , Biofilmes/efeitos dos fármacos , Titânio/química , Titânio/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Grafite/química , Grafite/farmacologia , Camundongos , Animais , Testes de Sensibilidade Microbiana
5.
Transfus Clin Biol ; 30(2): 189-194, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36257581

RESUMO

BACKGROUND: In China, the platelet donation interval is 14 days. The eligibility criterion of plateletpheresis donors (PD) is more stringent than that of whole blood donors, so the deferral causes are very complicated. However, the deferral prevalence and causes among PDs are not well known in China. OBJECTIVE: To analyse the deferral prevalence and influencing factors during pre-donation among PDs in a blood centre in Eastern China. METHODS: From December 26, 2020 to December 25, 2021, all data of potential PDs during pre-donation were extracted from the register system and collected using Microsoft Excel. The number of deferred visits and the corresponding causes were retrospectively analysed, and the re-donation rate of deferred donors was calculated. RESULTS: A total of 19,762 visits were included in the study. Of these 17,847 (90.3%) donated platelets successfully and 1915 (9.7%) were deferred. The prevalence of deferrals was high among those less than 35 years old (p < 0.05) and first-time donors (p = 0). The leading cause for deferral was elevated alanine transaminase (51.4%) followed by abnormal haematological parameters (37.15%). High white blood cell count was the first deferral factor (26.9%) in abnormal haematological parameters. In more than 2 ineligible items, low haemoglobin and haematocrit simultaneously were dominant (58.3%). The re-donation rate of repeat donors (65.4%) was higher than that of first-time donors (19.3%) (p = 0). CONCLUSION: The deferral prevalence in Chinese plateletpheresis donors was not high. First-time and young donors were more frequently deferred. The repeat donors should be of concern, especially with abnormal haematological parameters.


Assuntos
Doadores de Sangue , Plaquetoferese , Humanos , Adulto , Estudos Retrospectivos , Prevalência , Hematócrito
6.
ACS Appl Mater Interfaces ; 15(9): 12005-12016, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36827513

RESUMO

Ever-evolving advancements in films have fueled many of the developments in the field of electrochemical sensors. For biosensor application platforms, the fabrication of metal-organic framework (MOF) films on microscopically structured substrates is of tremendous importance. However, fabrication of MOF film-based electrodes always exhibits unsatisfactory performance, and the mechanisms of the fabrication and sensing application of the corresponding composites also need to be explored. Here, we report the fabrication of conformal MIL-53 (Fe) films on carbonized natural seaweed with the assistance of an oxide nanomembrane and a potential-dependent electrochemical dopamine (DA) sensor. The geometry and structure of the composite can be conveniently tuned by the experimental parameters, while the sensing performance is significantly influenced by the applied potential. The obtained sensor demonstrates ultrahigh sensitivity, a wide linear range, a low limit of detection, and a good distinction between DA and ascorbic acid at an optimized potential of 0.3 V. The underneath mechanism is investigated in detail with the help of theoretical calculations. This work bridges the natural material and MOF films and is promising for future biosensing applications.


Assuntos
Técnicas Biossensoriais , Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Carbono/química , Dopamina/química , Óxidos , Eletrodos , Técnicas Eletroquímicas
7.
Adv Healthc Mater ; 11(3): e2102042, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34787378

RESUMO

As the primary malignant tumor in the brain, glioblastoma exhibits a high mortality due to the challenges for complete treatment by conventional therapeutic methods. It is of great importance to develop innovative therapeutic agents and methods for treatment of glioblastoma. In this work, the imaging and therapy of glioblastoma are reported by using dye sensitized core-shell NaYF4 :Yb/Tm@NaYF4 :Nd nanoparticles with strong up/down-conversion luminescence, of which the ultraviolet up-conversion emissions at 348 and 365 nm are significantly enhanced by nearly 28 times and used to control the release of SO2 from 5-Amino-1,3-dihydrobenzo[c]thiophene 2,2-dioxide prodrug for gas therapy, and the second near-infrared (NIR-II) down conversion emission at 1340 nm is increased five times and applied for imaging. It is revealed that the released SO2 molecules not only cause oxidative stress damage of tumor cells, but also induce their pro-death autophagy by down-regulating the expression of p62 and up-regulating the ratio of LC3-II/LC3-I, ultimately inhibiting tumor growth. The work demonstrates the great potential of rare earth nano-platform with functions of NIR-II imaging and photo-controlled gas therapy in the diagnosis and treatment of orthotopic glioblastoma.


Assuntos
Glioblastoma , Nanopartículas , Encéfalo , Glioblastoma/diagnóstico por imagem , Glioblastoma/tratamento farmacológico , Humanos , Luminescência , Nanopartículas/uso terapêutico , Imagem Óptica
8.
Front Neurosci ; 16: 1014485, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36278009

RESUMO

Objective: Neuromelanin-sensitive magnetic resonance imaging (NM-MRI) technique was used to detect the changes of the locus coeruleus (LC) signals in Alzheimer's disease patients (AD), and to analyze its correlation with cognitive function. Materials and methods: A total of 27 patients with AD, 15 patients with mild cognitive impairment (MCI), and 25 healthy controls (HC) were examined by NM-MRI technique. ImageJ software was used to measure the LC signals. The locus coeruleus signal contrast ratios (LC-CRs) were calculated, along with the measurement of neuropsychological scales. Results: The LC-CRs of AD patients were significantly different from that of HC (p = 0.007, 95% CI: -0.053∼-0.007). However, such significant differences were not observed between MCI and HC (p = 1.000, 95% CI: -0.030∼0.024), AD and MCI (p = 0.050, 95% CI: -0.054∼0.000). Furthermore, a significant positive correlation was identified between LC-CRs and MMSE sub item Drawing (r = 0.484, p = 0.011) in the AD group, MoCA sub item Attention (r = 0.519, p = 0.047) in the MCI group. The area under the curve of LC-CRs in the diagnosis of AD was 0.749 (p = 0.002, 95% CI: 0.618∼0.880), with a sensitivity of 85.2% and a specificity of 56.0%. Conclusion: The NM-MRI technique could quantify the pathological degenerations of the LC in AD. Such LC degenerations can be employed to distinguish AD from healthy elderly.

9.
Acta Biomater ; 153: 494-504, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36115653

RESUMO

The field of nanomedicine-catalyzed tumor therapy has achieved a lot of progress; however, overcoming the limitations of the tumor microenvironment (TME) to achieve the desired therapeutic effect remains a major challenge. In this study, a nanocomposite hydrogel (GH@LDO) platform combining the nanozyme CoMnFe-layered double oxides (CoMnFe-LDO) and natural enzyme glucose oxidase (GOX) was engineered to remodel the TME to enhance tumor catalytic therapy. The CoMnFe-LDO is a nanozyme that can convert endogenous H2O2 into reactive oxygen species (ROS) and O2 to achieve chemodynamic therapy (CDT) and alleviate the hypoxic microenvironment. Meanwhile, GOX can catalyze the conversion of glucose and O2 to gluconic acid and H2O2, which not only represses the ATP production of tumor cells to achieve starvation therapy (ST), but also decreases the pH value of TME and supplies extra H2O2 to enhance the CDT effect. Furthermore, this well-designed CoMnFe-LDO possessed a high photothermal conversion efficiency of GH@LDO (66.63%), which could promote the generation of ROS to enhance the CDT effect and achieve photothermal therapy (PTT) under near-infrared light irradiation. The GH@LDO hydrogel performes cascade reaction which overcomes the limitation of the TME and achieves satisfactory CDT/ST/PTT synergetic effects in vitro and in vivo. This work provides a new strategy for remodeling the TME using nanomedicine to achieve precise tumor cascaded catalytic therapy. STATEMENT OF SIGNIFICANCE: At present, the focus of tumor therapy has begun to shift from monotherapy to combination therapy for improving the overall therapeutic effect. In this study, we synthesized a CoMnFe-LDO nanozyme composed of multiple transition metal oxides, which demonstrated improved peroxidase and oxidase activities as well as favorable photothermal conversion capability. The CoMnFe-LDO nanozyme was compounded with an injectable GH hydrogel crosslinked by GOX and horseradish peroxidase (HRP). This nanocomposite hydrogel overcame the limitations of weak acidity, H2O2, and O2 levels in the TME and achieved synergetic CDT, ST, and PTT effects based on the cascaded catalytic actions of CoMnFe-LDO and GOX to H2O2 and glucose.


Assuntos
Neoplasias , Óxidos , Humanos , Hidrogéis/uso terapêutico , Espécies Reativas de Oxigênio , Peróxido de Hidrogênio , Terapia Fototérmica , Nanogéis , Linhagem Celular Tumoral , Microambiente Tumoral , Glucose Oxidase , Neoplasias/patologia , Glucose , Reatores Biológicos
10.
Acta Biochim Biophys Sin (Shanghai) ; 43(9): 698-702, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21785112

RESUMO

Neogambogic acid (NGA), an active ingredient in garcinia, can inhibit the growth of some solid tumors and result in an anticancer effect. We hypothesize that NGA may be responsible for the inhibition of proliferation of human breast cancer cell line MCF-7 cells. To investigate its anticancer mechanism in vitro, MCF-7 cells were treated with various concentrations of NGA. Results of MTT (methyl thiazolyl tetrazolum) assay showed that treatment with NGA significantly reduced the proliferation of MCF-7 cells in a dose-dependent manner. NGA could increase the expression of the apoptosis-related proteins FasL, caspase-3, caspase-8, caspase-9, and Bax and decrease the expression of anti-apoptotic protein Bcl-2 accompanied by the mitochondrial transmembrane damage. The antiproliferative effect of NGA on MCF-7 cells is due to the G(0)/G(1) arrest, increased apoptosis and activation of Fas/FasL and cytochrome C pathway. These results provide an important insight into the cellular and molecular mechanisms through which NGA impairs the proliferation of breast cancer cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Terpenos/farmacologia , Xantonas/farmacologia , Antineoplásicos Fitogênicos/química , Western Blotting , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Caspase 3/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Proteína Ligante Fas/metabolismo , Feminino , Fase G1/efeitos dos fármacos , Garcinia/química , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estrutura Molecular , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Terpenos/química , Xantenos , Xantonas/química , Proteína X Associada a bcl-2/metabolismo , Receptor fas/metabolismo
11.
Adv Sci (Weinh) ; 8(16): e2004393, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34166584

RESUMO

Transmembrane charge (ion/electron) transfer is essential for maintaining cellular homeostasis and is involved in many biological processes, from protein synthesis to embryonic development in organisms. Designing implant devices that can detect or regulate cellular transmembrane charge transfer is expected to sense and modulate the behaviors of host cells and tissues. Thus, charge transfer can be regarded as a bridge connecting living systems and human-made implantable devices. This review describes the mode and mechanism of charge transfer between organisms and nonliving materials, and summarizes the strategies to endow implants with charge-transfer regulating or monitoring abilities. Furthermore, three major charge-transfer controlling systems, including wired, self-activated, and stimuli-responsive biomedical implants, as well as the design principles and pivotal materials are systematically elaborated. The clinical challenges and the prospects for future development of these implant devices are also discussed.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Próteses e Implantes , Transporte de Elétrons , Humanos
12.
J Mater Chem B ; 8(22): 4778-4812, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32226981

RESUMO

Copper chalcogenides have a simple general formula, variable atomic ratios, and complicated crystal structures, which lead to their wealth of optical, electrical, and magnetic properties with great potential for wide applications ranging from energy conversion to the biomedical field. Herein, we summarize the recent advances in (1) the synthesis of size- and morphology tunable nanostructures by different methods; (2) surface modification and functionalization for different purposes; and (3) bioapplications for diagnosis and treatment of tumors by different imaging and therapy methods, as well as antibacterial applications. We also briefly discuss the future directions and challenges of copper chalcogenide nanoparticles in the biomedical field.


Assuntos
Antineoplásicos/farmacologia , Calcogênios/farmacologia , Cobre/farmacologia , Nanopartículas Metálicas/química , Neoplasias/tratamento farmacológico , Antineoplásicos/química , Pesquisa Biomédica , Proliferação de Células/efeitos dos fármacos , Calcogênios/química , Cobre/química , Humanos , Neoplasias/patologia , Tamanho da Partícula , Propriedades de Superfície
13.
Colloids Surf B Biointerfaces ; 194: 111176, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32540767

RESUMO

Mussel inspired polydopamine (PDA) coatings have attracted a great deal of attention for their superior osteogenic property. Furthermore, recent investigations have demonstrated that vessel formation is crucial to bone regeneration. Hence, in the present study, the potential ability of polydopamine coatings with different oxidation degrees were systematically investigated in vitro to improve the angiogenic behavior of human umbilical vein endothelial cells (HUVECs). PDA was first coated on titanium (PDA-1#), and then oxidized by thermal treatment at 150 (PDA-2#) and 300 °C (PDA-3#), respectively. X-ray photoelectron spectroscopy (XPS) results revealed that phenolic hydroxyl (C-OH) and primary amino group (-NH2) on PDA coatings deceased after oxidation, while quinone (C=O) increased. In vitro cell culture experiments suggested that PDA-2# sample was most beneficial for the adhesion, migration, and proliferation of HUVECs. Furthermore, HUVECs cultured on PDA-2# sample also exhibited best tube formation, CD31 expression, vascular endothelial growth factor (VEGF) secretion, as well as angiogenic-associated gene expression abilities. Our study suggests that moderate oxidation of PDA coating with balanced quinone and amino group has excellent potential to enhance bone vascularization, and is thus promising for clinical application in orthopedic implants.


Assuntos
Células Endoteliais da Veia Umbilical Humana , Neovascularização Fisiológica , Proliferação de Células , Humanos , Indóis , Molécula-1 de Adesão Celular Endotelial a Plaquetas , Polímeros , Propriedades de Superfície , Fator A de Crescimento do Endotélio Vascular
14.
Colloids Surf B Biointerfaces ; 173: 681-688, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30384264

RESUMO

Graphene halides are promising two-dimensional systems which have interesting physical and chemical properties. In particular, high quality fluorinated graphene offers a great potential in modulating variable properties by regulating its surface microstructure. Moreover, the fluorine introduction and carbon-fluorine bonding characters will enable some interesting biological response. Here, the biological responses to bacteria and cells of fluorinated graphene were studied. Present work revealed that partially fluorinated graphene behaved satisfactory antibacterial ability. Fluorinated graphene showed well facilitating function to cell adhesion in early period, however, after a longer incubation period, the enhanced intracellular ROS level in rBMSCs on the fully fluorinated graphene gives rise to the decrease of cell viability. It was found that there is no statistical difference in the activity of alkaline phosphatase (ALP) and matrix mineralization of rBMSCs on pristine graphene, partially fluorinated graphene and fluorographene. In addition, the introduction of fluorine into pristine graphene plane reduced the adhesion and aggregation of blood platelets due to the attenuation of π-π interaction between material surface and blood protein. The findings in this work revealed that partial fluorinated graphene exhibited better antibacterial ability and cytocompatibility, outperforming pristine graphene and fluorographene.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Grafite/farmacologia , Fosfatase Alcalina/metabolismo , Animais , Antibacterianos/química , Biomarcadores/metabolismo , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Grafite/química , Halogenação , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Testes de Sensibilidade Microbiana , Agregação Plaquetária/efeitos dos fármacos , Cultura Primária de Células , Ratos , Espécies Reativas de Oxigênio/agonistas , Espécies Reativas de Oxigênio/metabolismo
15.
Bioact Mater ; 3(3): 341-346, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29988418

RESUMO

Duo to their superior physicochemical properties, graphene and its derivatives (GDs), such as graphene oxide (GO) and reduced graphene oxide (rGO), have attracted extensive research interests around the world. In recent years, antibacterial activities of GDs have aroused wide concern and substantial works have been done. However, the underlying antibacterial mechanisms still remain controversial. Antibacterial activities of GDs vary with various factors, such as size, number of layers, oxygen-containing groups, and experimental surroundings. We assume that combination types between graphene oxide and substrate may affect the antibacterial activity. Therefore, in this work, GO was fixed on the titanium surface with three kinds of combination types including drop with gravitational effects (GO-D), electrostatic interaction (GO-APS) and electrophoretic deposition (GO-EPD), and the antibacterial activities in vitro were systematically investigated. Results showed that combination types affected the ability of GO for preventing Staphylococcus aureus (S. aureus) from gathering, sharpness of wrinkles or edges and reactive oxygen spices (ROS) levels. Once S. aureus are in the form of separation without aggregation, GO can effectively interact with them and kill them with sharp wrinkles or edges and high ROS levels. GO-EPD could effectively prevent S. aureus from gathering, own sharp wrinkles or edges and could generate higher ROS levels. As a result, GO-EPD exhibited optimal antibacterial activity against S. aureus, followed by GO-APS and GO-D.

16.
West J Nurs Res ; 40(6): 874-888, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-28395593

RESUMO

This study aimed to evaluate the effects of self-management educational intervention on the symptoms of patients with functional constipation. From January 2014 to April 2015, 66 patients with functional constipation were randomly assigned into intervention group receiving intensive educational interventions and control group receiving routine nursing care. The constipation score of all clinical symptoms (Bristol stool form scale, defecation interval, incomplete evacuation, evacuatory difficulty) at 1 month postdischarge were all significantly lower in the intervention group than in the control group (all, p < .05). At 1 month postdischarge, the intervention group had a significantly higher proportion of patients with good health habits (reasonable diet, regular exercise, good defecation habits, proper use of laxatives) as compared with the control group (all, p < .05). These data suggest educational intervention can effectively improve constipation symptoms and compliance with treatment of patients, and lead to the development of good health habits.


Assuntos
Constipação Intestinal/terapia , Papel do Profissional de Enfermagem , Educação de Pacientes como Assunto/métodos , Autogestão , Dieta , Feminino , Humanos , Laxantes/administração & dosagem , Masculino , Pessoa de Meia-Idade , Pesquisa em Enfermagem , Cooperação do Paciente
17.
ACS Appl Mater Interfaces ; 10(49): 42018-42029, 2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30412372

RESUMO

The interactions between material surfaces and bacteria/cells have been widely investigated, based on which biomaterials with antibacterial and osteogenic abilities can be designed to conquer implant failures. The pH of environments is known to affect bacterial growth and bone formation/resorption, and it is possible that the antibacterial and osteogenic abilities of biomaterials can be simultaneously improved by regulating their surface alkalinity. Herein, we fabricated many kinds of films with various alkalinity levels on titanium surface to explore the effect of local alkaline microenvironments around material surfaces on the behaviors of bacteria and osteogenic cells. Both Gram-positive and -negative bacteria were cultured on sample surfaces to investigate their antibacterial effects. Cell adhesion, proliferation, and alkaline phosphatase (ALP) activities were investigated by culturing both bone mesenchymal stem cells (MSCs) and osteoblast cells on sample surfaces. The results show that an appropriate local alkaline environment can effectively inhibit the growth of both Gram-positive and -negative bacteria through inactivating ATP synthesis and inducing oxidative stress. Meanwhile, it can promote the osteogenic differentiation of bone MSCs and enhance the proliferation and ALP activities of osteoblast cells. In conclusion, material surfaces endowed with appropriate alkalinity can possess antibacterial and osteogenic properties, which provide a novel strategy to design multifunctional biomaterials for bone generation.


Assuntos
Proliferação de Células/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/metabolismo , Staphylococcus aureus/crescimento & desenvolvimento , Nicho de Células-Tronco , Titânio , Animais , Aderência Bacteriana/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Camundongos , Ratos , Titânio/química , Titânio/farmacologia
18.
J Mater Chem B ; 6(13): 2004-2012, 2018 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32254366

RESUMO

Implant failure of titanium and its alloys still occurs due to insufficient osseointegration and implant associated infections. Therefore, titanium implants with enhanced osseointegration and antibacterial activities are desirable. To achieve this goal, graphene oxide (GO) as a dual zinc/magnesium (Zn/Mg) ion carrier and release platform was constructed on the titanium surface by cathode electrophoresis deposition. Rat bone mesenchymal stem cells were used to investigate the osteogenic activity. Gram-negative E. coli was utilized to assess the antibacterial activities. Results show that GO co-doped with Mg and Zn ions with a sustained and slow release exhibited the best osteogenic activity among all the samples by stimulating the expressions of osteogenesis related genes containing alkaline phosphatase (ALP), type I collagen (Col-I), osteocalcin (OCN), and osteopontin (OPN), and by promoting the alkaline phosphatase activity and extracellular matrix mineralization. The existence of GO endowed titanium with superior antibacterial activities against Gram-negative E. coli. Due to the synergistic effects of GO, Mg and Zn ions, a titanium surface with enhanced osseointegration and antibacterial activities was achieved.

19.
Colloids Surf B Biointerfaces ; 163: 175-183, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29291503

RESUMO

It is important to fabricate an implant possessing environment sensitive drug delivery. In this work, the construction of 3D porous structure on polyetheretherketone (PEEK) surface and pH sensitive polymer, chitosan, was introduced. The smart release of doxorubicin can be realized on the 3D porous surface of PEEK loading chitosan. We give a feasible explanation for the effect of chitosan on smart drug release according to Henderson-Hasselbalch equation. Furthermore, the intracellular drug content of the cell cultured on the samples with highest chitosan is significantly higher at pH 4.0, whereas lower at pH 7.4 than other samples. The smart release of doxorubicin via modification with chitosan onto 3D porous PEEK surface paves the way for the application of PEEK in drug loading platform for recovering bone defect caused by malignant bone tumor.


Assuntos
Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Cetonas/química , Polietilenoglicóis/química , Benzofenonas , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Fluorescência , Humanos , Concentração de Íons de Hidrogênio , Polímeros , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície
20.
ACS Appl Mater Interfaces ; 9(14): 12253-12263, 2017 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-28345852

RESUMO

Graphene oxide has attracted widespread attention in the biomedical fields due to its excellent biocompatibility. Herein we investigated the layer-number dependent antibacterial and osteogenic behaviors of graphene oxide in biointerfaces. Graphene oxide with different layer numbers was deposited on the titanium surfaces by cathodal electrophoretic deposition with varied deposition voltages. The initial cell adhesion and spreading, cell proliferation, and osteogenic differentiation were observed from all the samples using rat bone mesenchymal stem cells. Both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were used to investigate the antibacterial effect of the modified titanium surfaces. Cocultures of human gingival fibroblasts (HGF) cells with Escherichia coli and Staphylococcus aureus were conducted to simulate the conditions of the clinical practice. The results show that the titanium surfaces with graphene oxide exhibited excellent antibacterial and osteogenic effects. Increasing the layer-number of graphene oxide resulted in the augment of reactive oxygen species levels and the wrinkling, which led to the antibacterial and osteogenic effects, respectively. Compared to pure titanium surface in the cells-bacteria coculture process, the modified titanium surfaces with graphene oxide exhibited higher surface coverage percentage of cells.


Assuntos
Titânio/química , Animais , Antibacterianos , Grafite , Humanos , Células-Tronco Mesenquimais , Osteogênese , Óxidos , Ratos , Propriedades de Superfície
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