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1.
Materials (Basel) ; 17(9)2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38730893

RESUMEN

Metakaolin-based geopolymers have substantial potential as replacements for cement, but their relatively inferior mechanical properties restrict their application. This paper aims to enhance the mechanical properties of metakaolin-based geopolymers by incorporating appropriate amounts of calcium sources. CaCO3, Ca(OH)2, and CaSO4 are three types of calcium sources commonly found in nature and are widely present in various industrial wastes. Thus, the effects of these three calcium sources on the performance of metakaolin-based geopolymers were studied. Through the analysis of the mechanical properties, heat-release behavior during hydration, hydration products, and microstructure of geopolymers, the effectiveness of the aforementioned calcium sources in improving the performance of metakaolin-based geopolymer was evaluated, and the mechanisms of action were elucidated. The results indicate that the pozzolanic reaction between CH and MK could promote MK hydration and increase the proportion of CASH gel in the hydration products, thereby facilitating the setting of the geopolymer and enhancing its strength. CS could react with the active aluminates in MK to form ettringite, thus forming a higher early strength. CC had a lower reactivity with MK and does not improve the performance of MK-based geopolymers.

2.
World J Gastrointest Surg ; 16(1): 173-185, 2024 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-38328335

RESUMEN

BACKGROUND: Recently, research has linked Helicobacter pylori (H. pylori) stomach infection to colonic inflammation, mediated by toxin production, potentially impacting colorectal cancer occurrence. AIM: To investigate the risk factors for post-colon polyp surgery, H. pylori infection, and its correlation with pathologic type. METHODS: Eighty patients who underwent colon polypectomy in our hospital between January 2019 and January 2023 were retrospectively chosen. They were then randomly split into modeling (n = 56) and model validation (n = 24) sets using R. The modeling cohort was divided into an H. pylori-infected group (n = 37) and an H. pylori-uninfected group (n = 19). Binary logistic regression analysis was used to analyze the factors influencing the occurrence of H. pylori infection after colon polyp surgery. A roadmap prediction model was established and validated. Finally, the correlation between the different pathological types of colon polyps and the occurrence of H. pylori infection was analyzed after colon polyp surgery. RESULTS: Univariate results showed that age, body mass index (BMI), literacy, alcohol consumption, polyp pathology type, high-risk adenomas, and heavy diet were all influential factors in the development of H. pylori infection after intestinal polypectomy. Binary multifactorial logistic regression analysis showed that age, BMI, and type of polyp pathology were independent predictors of the occurrence of H. pylori infection after intestinal polypectomy. The area under the receiver operating characteristic curve was 0.969 [95% confidence interval (95%CI): 0.928-1.000] and 0.898 (95%CI: 0.773-1.000) in the modeling and validation sets, respectively. The slope of the calibration curve of the graph was close to 1, and the goodness-of-fit test was P > 0.05 in the two sets. The decision analysis curve showed a high rate of return in both sets. The results of the correlation analysis between different pathological types and the occurrence of H. pylori infection after colon polyp surgery showed that hyperplastic polyps, inflammatory polyps, and the occurrence of H. pylori infection were not significantly correlated. In contrast, adenomatous polyps showed a significant positive correlation with the occurrence of H. pylori infection. CONCLUSION: Age, BMI, and polyps of the adenomatous type were independent predictors of H. pylori infection after intestinal polypectomy. Moreover, the further constructed column-line graph prediction model of H. pylori infection after intestinal polypectomy showed good predictive ability.

3.
Adv Sci (Weinh) ; 11(5): e2305152, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38044308

RESUMEN

Hand gesture plays an important role in many circumstances, which is one of the most common interactive methods in daily life, especially for disabled people. Human-machine interaction is another popular research topic to realize direct and efficient control, making machines intelligent and maneuverable. Here, a special human-machine interaction system is proposed and namedas computer-vision (CV) based gesture-metasurface interaction (GMI) system, which can be used for both direct beam manipulations and real-time wireless communications. The GMI system first needs to select its working mode according to the gesture command to determine whether to perform beam manipulations or wireless communications, and then validate the permission for further operation by recognizing unlocking gesture to ensure security. Both beam manipulation and wireless communication functions are validated experimentally, which show that the GMI system can not only realize real-time switching and remote control of different beams through gesture command, but also communicate with a remote computer in real time by translating the gesture language to text message. The proposed non-contact GMI system has the advantages of good interactivity, high flexibility, and multiple functions, which can find potential applications in community security, gesture-command smart home, barrier-free communications, and so on.

4.
Aging Cell ; 23(3): e14057, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38044573

RESUMEN

Aging is a complex biological process leading to impaired functions, with a variety of hallmarks. In the testis of Drosophila, the terminal epithelium region is involved in spermatid release and maturation, while its functional diversity and regulatory mechanism remain poorly understood. In this study, we performed single-cell RNA-sequencing analysis (scRNA-seq) to characterize the transcriptomes of terminal epithelium in Drosophila testes at 2-, 10 and 40-Days. Terminal epithelium populations were defined with Metallothionein A (MtnA) and subdivided into six novel sub-cell clusters (EP0-EP5), and a series of marker genes were identified based on their expressions. The data revealed the functional characteristics of terminal epithelium populations, such as tight junction, focal adhesion, bacterial invasion, oxidative stress, mitochondrial function, proteasome, apoptosis and metabolism. Interestingly, we also found that disrupting genes for several relevant pathways in terminal epithelium led to male fertility disorders. Moreover, we also discovered a series of age-biased genes and pseudotime trajectory mediated state-biased genes during terminal epithelium aging. Differentially expressed genes during terminal epithelium aging were mainly participated in the regulation of several common signatures, e.g. mitochondria-related events, protein synthesis and degradation, and metabolic processes. We further explored the Drosophila divergence and selection in the functional constraints of age-biased genes during aging, revealing that age-biased genes in epithelial cells of 2 Days group evolved rapidly and were endowed with greater evolutionary advantages. scRNA-seq analysis revealed the diversity of testicular terminal epithelium populations, providing a gene target resource for further systematic research of their functions during aging.


Asunto(s)
Drosophila , Testículo , Animales , Masculino , Testículo/metabolismo , Drosophila/genética , Transcriptoma/genética , Envejecimiento/genética , Epitelio
5.
Biochem Genet ; 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37962691

RESUMEN

An increasing number of circRNAs have been found to be involved in the development of gastric cancer. However, the function of circ_0003789 in regulating gastric cancer progression is unclear. Here, we aimed to investigate the expression, function and molecular mechanism of circ_0003789 in gastric cancer pathogenesis. Circ_0003789, miR-429 and ZFP36 ring finger protein like 2 (ZFP36L2) mRNA were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was illustrated by 5-Ethynyl-2'-deoxyuridine (Edu), cell counting kit-8 (CCK-8) and colony formation assays. Apoptosis was determined by flow cytometry. Protein level was detected by Western blotting assay. Xenograft assays were used for functional analysis of circ_0003789 in vivo. The relationship between miR-429 and circ_0003789 or ZFP36L2 was predicted by starbase3.0 online database and identified by dual luciferase reporter assay. The expression levels of circ_0003789 and ZFP36L2 were significantly upregulated in gastric cancer tissues and cells, while the expression of miR-429 was downregulated. Downregulation of circ_0003789 inhibited gastric cancer cell growth and invasion and promoted apoptosis in vitro. Circ_0003789 acted as a sponge of miR-429. Moreover, miR-429 silencing by miR-429 inhibitors attenuated the effects of circ_0003789 interference on cell growth, apoptosis and invasion. ZFP36L2 was targeted by miR-429, and the effects of miR-429 on cell growth, invasion and apoptosis were attenuated by ZFP36L2 overexpression. Circ_0003789 could enhance ZFP36L2 expression by interacting with miR-429. Silencing of circ_0003789 inhibited tumor growth in vivo. Circ_0003789 regulates tumor progression in gastric cancer through miR-429/ZFP36L2 axis. This finding implies that circ_0003789 may be a therapeutic target for gastric cancer.

6.
Bioeng Transl Med ; 8(6): e10540, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38023724

RESUMEN

The management of infected wounds is still an intractable challenge in clinic. Development of antibacterial wound dressing is of great practical significance for wound management. Herein, a natural-derived antibacterial drug, tannic acid (TA), was incorporated into the electrospun polyvinyl alcohol (PVA) fiber (TA/PVA fiber, 952 ± 40 nm in diameter). TA worked as a cross-linker via hydrogen bonding with PVA to improve the physicochemical properties of the fiber and to reach a sustained drug release (88% release of drug at 48 h). Improved mechanical property (0.8-1.2 MPa) and computational simulation validated the formation of the hydrogen bonds between TA and PVA. Moreover, the antibacterial and anti-inflammatory characteristics of TA laid the foundation for the application of TA/PVA fiber in repairing infected wounds. Meanwhile, in vitro studies proved the high hemocompatibility and cytocompatibility of TA/PVA fiber. Further in vivo animal investigation showed that the TA/PVA fiber promoted the repair of infected wound by inhibiting the bacterial growth, promoting granulation formation, and collagen matrix deposition, accelerating angiogenesis, and inducing M2 macrophage polarization within 14 days. All the data demonstrated that the TA cross-linked fiber would be a potent dressing for bacteria-infected wound healing.

7.
Chemosphere ; 338: 139516, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37454983

RESUMEN

This study was conducted on a full-scale (500 t/d) municipal solid waste incinerator (MSWI), investigating the influence of different loads on the emission of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/Fs) and their removal by selective catalytic reduction (SCR) system. The total concentration of PCDD/Fs at the SCR inlet under 100% load was higher than that under 80% load. The changing loads caused different distribution characteristics of PCDD/Fs at the SCR inlet, and the dominant congeners changed from high-chlorinated PCDDs (80% load) to low-chlorinated PCDFs (100% load). Moreover, the increased load enhanced the removal efficiency of PCDD/Fs by SCR from 17.3% to 64.2%, which was influenced by the inlet PCDD/F distribution and the moisture content. The high-chlorinated PCDD/Fs with the more stable structure were more difficult to be deteriorated and the high moisture content can weaken the catalytic activity of SCR catalysts. Correlation analysis was used to study the relationship between major air pollutants and PCDD/F emissions. The results showed that HCl positively correlated with PCDD/F emission concentrations, while NOx and SO2 negatively correlated. The results of this study can provide a reference for MSWI to operate properly under variable loads.


Asunto(s)
Contaminantes Atmosféricos , Dibenzodioxinas Policloradas , Dibenzodioxinas Policloradas/análisis , Residuos Sólidos/análisis , Incineración , Dibenzofuranos/análisis , Contaminantes Atmosféricos/análisis , Dibenzofuranos Policlorados/análisis
8.
Int J Mol Sci ; 24(2)2023 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-36674715

RESUMEN

Staphylococcus aureus Cas9 (SaCas9) is a widely used genome editing tool. Understanding its molecular mechanisms of DNA cleavage could effectively guide the engineering optimization of this system. Here, we determined the first cryo-electron microscopy structure of the SaCas9-sgRNA-DNA ternary complex. This structure reveals that the HNH nuclease domain is tightly bound to the cleavage site of the target DNA strand, and is in close contact with the WED and REC domains. Moreover, it captures the complete structure of the sgRNA, including the previously unresolved stem-loop 2. Based on this structure, we build a full-length model for the ternary complex in cleavage state. This model enables identification of the residues for the interactions between the HNH domain and the WED and REC domains. Moreover, we found that the stem-loop 2 of the sgRNA tightly binds to the PI and RuvC domains and may also regulate the position shift of the RuvC domain. Further mutagenesis and molecular dynamics simulations supported the idea that the interactions of the HNH domain with the WED and REC domains play an important role in the DNA cleavage. Thus, this study provides new mechanistic insights into the DNA cleavage of SaCas9 and is also useful for guiding the future engineering of SaCas9-mediated gene editing systems.


Asunto(s)
Sistemas CRISPR-Cas , ARN Guía de Sistemas CRISPR-Cas , Microscopía por Crioelectrón , ADN/química , Edición Génica
9.
Mol Biotechnol ; 65(8): 1346-1358, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36577835

RESUMEN

Growing evidence has suggested that lncRNAs play a significant role in the development of colorectal adenocarcinoma. LncRNA LINC02535 was a potential novel lncRNA marker of neoplastic processes of the colon. Nevertheless, the function and mechanisms of LINC02535 in colorectal adenocarcinoma remain unclear. Proteins levels were measured by western blotting. EdU, CCK-8, Transwell, and wound healing assays were performed to investigate the function of LINC02535 in colorectal adenocarcinoma. The distribution of LINC02535 in cells was evaluated by subcellular fractionation assay. The interaction among RNAs was identified by luciferase reporter and RIP assays. In this study, our findings revealed that LINC02535 was highly expressed in colorectal adenocarcinoma cells. Knockdown of LINC02535 inhibited colorectal adenocarcinoma cell proliferation, migration, and invasion. Mechanistically, LINC02535 bound with miR-30d-5p and worked as a competing endogenous RNA to facilitate the expression of messenger RNA chromodomain helicase DNA-binding protein 1 (CHD1). miR-30d-5p directly targeted the sequence of CHD1 3'-untranslated region. Notably, CHD1 upregulation abolished the suppressive influence of LINC02535 inhibition on the malignant phenotypes of colorectal adenocarcinoma cells. Overall, it was disclosed that LINC02535 played an oncogenic role in colorectal adenocarcinoma progression by sponging miR-30d-5p to upregulate CHD1 expression.


Asunto(s)
Adenocarcinoma , Neoplasias Colorrectales , MicroARNs , ARN Largo no Codificante , Humanos , Adenocarcinoma/genética , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Neoplasias Colorrectales/genética , ADN Helicasas/genética , Proteínas de Unión al ADN/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo
10.
Materials (Basel) ; 15(22)2022 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-36431370

RESUMEN

The individual coupling processes of two-phase materials are controlled to some extent by damage theory. However, the existing theory is not sufficient to explain the effect of pore pressure on mortar materials under freeze-thaw action. In order to predict the resistance of saturated mortars during rapid cooling and to describe the physical behavior of the pore structure, the authors derived in detail the governing equations of saturated mortars during freezing in the framework of the pore elasticity theory and analyzed the sensitivity of physical parameters to the influence of temperature stresses by means of stress-strain calculations. In addition, the effects of phase change and latent heat of freezing on the local thermodynamic equilibrium are considered, and a mathematical model is established for quantitatively simulating the temperature distribution of the specimen. This model is reformulated and extended in the current work to intuitively reveal the effect of concrete dimensions on the temperature hysteresis effect. The results of the numerical model calculations show that during the freezing process, for the specimen with dimensions of 50 mm × 50 mm × 50 mm and a water-cement ratio of 0.6, the maximum temperature difference from center to surface is 10 °C, the maximum vertical strain on the surface is 4.27 × 10-4, and the maximum pore water pressure at the center of the specimen is 76 MPa. The model calculation results present a similar pattern to the physical interpretation and reference results, thus effectively evaluating the freezing damage process of saturated mortar.

11.
Carbohydr Polym ; 281: 119017, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35074133

RESUMEN

Bacterial infections on open wounds have always been a threat to human health. Herein, we prepared a silver (Ag)-polydopamine (PDA)/bacterial cellulose (BC)-chitosan (CTS) film using biological self-generation and in situ reduction. CTS was added to culture medium to allow BC to intertwine with CTS during film formation. Silver nitrate was reduced in situ to Ag nanoparticles under ultraviolet irradiation, and the nanoparticles were well dispersed in the BC-CTS film with the help of PDA, which worked synergistically with the CTS. The Ag-PDA/BC-CTS film was enriched in functional groups, and it had good tensile and swelling properties. The inhibition film demonstrated broad-spectrum inhibition of Gram-positive and Gram-negative bacteria, and this inhibition was maintained at more than 80% after 48 h of continuous use. The good biocompatibility of the film was verified using NIH3T3 fibroblasts. The results suggested that the Ag-PDA/BC-CTS film inhibited the growth of harmful bacteria while having little effect on healthy cells.


Asunto(s)
Quitosano , Nanopartículas del Metal , Animales , Antibacterianos/farmacología , Bacterias , Celulosa/farmacología , Quitosano/farmacología , Bacterias Gramnegativas , Bacterias Grampositivas , Humanos , Nanopartículas del Metal/toxicidad , Ratones , Pruebas de Sensibilidad Microbiana , Células 3T3 NIH , Plata/farmacología
12.
Opt Lett ; 46(23): 5790-5793, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34851891

RESUMEN

In this Letter, we propose an approach to generate high-purity orbital angular momentum (OAM) vortex waves using an amplitude-and-phase metasurface (APM). By varying the square split ring opening and orientation angles, the cross-polarized reflection response of the proposed structure can yield full phase and amplitude coverage. Based on the traditional phase-only metasurface (POM), the Chebyshev synthesis method (CSM) is applied to array the metasurface amplitude distribution. Metasurfaces with modes l of 1, 2, 3, and 4 are designed. Compared with the POM, the APM can effectively improve the vortex beam quality and OAM mode purity. The measured results agree well with full-wave simulations. The presented method provides a new, to the best of our knowledge, way to design high-purity OAM generators based on metasurfaces.

13.
Vet Med Sci ; 7(6): 2250-2259, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34455709

RESUMEN

BACKGROUND: In highly intensive dairy farms, cows often suffer from metabolic disorders that cause severe oxidative stress. OBJECTIVES: This study aimed to observe correlations and associations of oxidative stress-related indicators with milk compositions and metabolites. METHODS: Twenty-two multiparous Holstein dairy cows in early lactation were randomly selected from a commercial dairy farm. The morning milk was collected for composition and metabolites analysis. Blood was sampled via the tail vein to analyze oxidative stress-related indicators (reactive oxygen species, ROS; catalase, CAT; superoxide dismutase, SOD; glutathione peroxidase, GPX; malondialdehyde, MDA) and metabolites. RESULTS: Results showed that ROS were positively correlated with CAT, GPX, SOD, and MDA. However, the levels of CAT, GPX, and SOD were negatively related to milk fat (P  <  0.05). Nineteen serum and 7 milk metabolites were selected from detectable metabolites according to their correlations with ROS, CAT, GPX, and SOD (P  <  0.05). Metabolic pathway analysis and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed that these metabolites are primarily involved in the metabolic pathways of carbohydrates and amino acids. CONCLUSIONS: This study gave us a better understanding on oxidative stress that ROS not only increased oxidative damage (MDA) in dairy cows, but also altered some metabolites involved in amino acid and carbohydrate metabolism.


Asunto(s)
Lactancia , Leche , Animales , Antioxidantes/metabolismo , Bovinos , Femenino , Leche/metabolismo , Estrés Oxidativo , Superóxido Dismutasa/metabolismo
14.
Tissue Cell ; 72: 101591, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34325277

RESUMEN

OBJECTIVE: To study the possible effects of miR-26b-5p on fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS) through targeting enhancer of zeste homolog 2 (EZH2). METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect miR-26b-5p and EZH2 expressions in synovial tissues of RA patients and healthy controls. Dual luciferase reporter assay was adopted to verify the targeting relationship between miR-26b-5p and EZH2. RA-FLS was divided into Blank, mimics NC, mimics, NC siRNA, EZH2 siRNA and inhibitors + EZH2 siRNA groups, followed by the assessment of proliferation, apoptosis, migration and invasion. The expression of genes and proteins in RA-FLS was tested by qRT-PCR and western blotting, respectively. RESULTS: MiR-26b-5p expression was lower, while EZH2 expression was higher in synovial tissue of RA patients than healthy controls; and miR-26b-5p was negatively correlated with the EZH2 in synovial tissue of RA patients, which were both related with disease activities. MiR-26b-5p can target EZH2 in RA-FLS. In vitro, miR-26b-5p mimics down-regulated EZH2 expression in RA-FLS. Compared with EZH2 siRNA group, the miR-26b-5p expression in inhibitors + EZH2 siRNA group was reduced, but EZH2 expression was increased. EZH2 siRNA inhibited the proliferation, invasion and migration of RA-FLS, promoted cell apoptosis, and inhibited the expression of TNF-α, IL-1ß, IL-6, IL-17, MMP-2, MMP-9, which were reversed by miR-26b-5p inhibitor. CONCLUSION: MiR-26b-5p may affect the biological characteristics of RA-FLS via targeting EZH2, including proliferation, apoptosis, invasion and migration, as well as the secretion of cytokines, thus playing a potential therapeutic role in RA.


Asunto(s)
Artritis Reumatoide/patología , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Fibroblastos/patología , MicroARNs/metabolismo , Anciano , Apoptosis/fisiología , Artritis Reumatoide/metabolismo , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Femenino , Fibroblastos/metabolismo , Regulación de la Expresión Génica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Sinoviocitos/metabolismo , Sinoviocitos/patología
15.
iScience ; 24(3): 102150, 2021 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-33665569

RESUMEN

Black tea is the most widely consumed tea drink in the world and has consistently been reported to possess anti-aging benefits. However, whether theaflavins, one type of the characteristic phytochemicals in black tea extracts, are involved in regulating aging and lifespan in consumers remains largely unknown. In this study, we show that theaflavins play a beneficial role in preventing age-onset intestinal leakage and dysbiosis, thus delaying aging in Drosophila. Mechanistically, theaflavins regulate the condensate assembly of Imd to negatively govern the overactivation of Imd signals in fruit fly intestines. In addition, theaflavins prevent DSS-induced colitis in mice, suggesting theaflavins play a role in modulating intestinal integrity. Overall, our study reveals a molecular mechanism by which theaflavins regulate gut homeostasis likely through controlling Imd coalescence.

16.
Zookeys ; 1011: 85-100, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33551652

RESUMEN

A new Sillago species, the black-banded sillago, Sillago nigrofasciata sp. nov., is described based on 302 specimens sampled from the southern coast of China. Morphological comparisons have been conducted between the new species and ten other Sillago species. The results show that the new species is characterized by a black mid-lateral band below the lateral line when fresh; other characteristics are similar to those of Sillago sihama but subtle differences exist on the swim bladder between Sillago nigrofasciata sp. nov. and S. sihama. A detailed description and illustrations are provided for the new species. The validity of this new species is also supported by a genetic comparison using sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene.

17.
Carbohydr Polym ; 257: 117671, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33541624

RESUMEN

It is difficult to obtain stable multifunctional silver-containing materials that are suitable for use as wound dressings. To solve this problem, we added graphene oxide (GO) to an acetobacter culture medium and used a biological blending self-growth method to fix GO onto the bacterial cellulose to form a mixed-growth film. We then used polydopamine to fix AgNPs to obtain a novel silver-based cellulose wound dressing. This composite material was characterized by infrared spectroscopy, electron microscopy, and X-ray diffractometry, and the results showed that silver nanoparticles uniformly covered the material surface, while graphene was wrapped in a layer of bacterial cellulose. This composite film was conductive and produced a weak current, and it generated heat when a voltage was applied. This allowed it to accelerate wound cell migration and promote wound healing. In addition, AgNPs immobilized on the surface released Ag+, which generated a large number of oxidizing free radicals that killed and bacteria. The in vitro cytotoxicity tests showed that the Ag-pDA/BC (rGO) composite film has excellent biocompatibility, giving it good application prospects for wound dressings.


Asunto(s)
Celulosa/química , Fibroblastos/metabolismo , Grafito/química , Nanopartículas del Metal/química , Plata/química , Cicatrización de Heridas/efectos de los fármacos , Animales , Materiales Biocompatibles , Biopelículas , Conductividad Eléctrica , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Radicales Libres , Gluconacetobacter xylinus , Técnicas In Vitro , Ratones , Células 3T3 NIH , Nanopartículas/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
18.
J Mater Chem B ; 8(7): 1359-1370, 2020 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-31840731

RESUMEN

Topical wound dressings with various silver compositions that exhibit effective bacterial inhibition properties are often used to treat infected wounds. However, a silver dressing with no bioactive functionality will typically delay subsequent wound repair processes. Therefore, development of a simple wound dressing containing silver and loaded with a bioactive drug is a very attractive solution. Herein, we developed a silver crosslinked injectable chitosan-silver hydrogel as a silver immobilization matrix, loaded with basic fibroblast growth factor (bFGF) as its cargo (namely, bFGF@CS-Ag) for treatment of both acute and infected wounds. The in vivo results showed that bFGF@CS-Ag significantly enhanced infectious wound regeneration compared to that of acute wounds. Further investigation demonstrated that the improved wound repair by bFGF@CS-Ag was ascribed to the effectiveness of bacterial inhibition, the promotion of granulation formation, collagen deposition, neovascularization and re-epithelization, and to the reduction of the inflammatory response through promotion of M2 macrophage polarization. These results proved that the immobilization of silver in the hydrogel not only reduced the side effects of silver on the bioactivity of bFGF but also allowed elution of bFGF in a controlled release manner. Thus, this novel system has promising therapeutic potential for topical treatment of wounds.


Asunto(s)
Reactivos de Enlaces Cruzados/farmacología , Factor 2 de Crecimiento de Fibroblastos/farmacología , Hidrogeles/farmacología , Plata/farmacología , Cicatrización de Heridas/efectos de los fármacos , Infección de Heridas/tratamiento farmacológico , Animales , Reactivos de Enlaces Cruzados/síntesis química , Reactivos de Enlaces Cruzados/química , Factor 2 de Crecimiento de Fibroblastos/química , Hidrogeles/síntesis química , Hidrogeles/química , Sustancias Macromoleculares/síntesis química , Sustancias Macromoleculares/química , Sustancias Macromoleculares/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Plata/química , Infección de Heridas/microbiología , Infección de Heridas/patología
19.
Biomaterials ; 222: 119398, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31487582

RESUMEN

Hydrogen sulfide (H2S), as a gaseous messenger, exhibits potential therapeutic effects in biological and clinical applications. Herein, an in situ forming biomimetic hyaluronic acid (HA) hydrogel was used as a matrix to dope a pH-controllable H2S donor, JK1, to form a novel HA-JK1 hybrid system. This HA-JK1 hydrogel was designed as an ideal delivery scaffold for JK1 with pH-dependent prolonged H2S releasing profile. In vitro study suggested that JK1 could induce the polarization of M2 phenotype indicating a higher pro-healing efficiency of macrophages. The in vivo studies on dermal wounds showed that the HA-JK1 hybrid hydrogel significantly accelerated the wound regeneration process through enhanced re-epithelialization, collagen deposition, angiogenesis and cell proliferation. Furthermore, the in vivo results also demonstrated a higher level of M2 polarization in HA-JK1 treated group with reduced inflammation and improved wound remodeling effects, which was consistent with the in vitro results. These observations could be considered as a key to the efficient wound treatment. Therefore, we suggest that HA-JK1 can be used as a novel wound dressing material toward cutaneous wound model in vivo. This system should significantly enhance wound regeneration through the release of H2S that induces the expression of M2 macrophage phenotype.


Asunto(s)
Hidrogeles/química , Sulfuro de Hidrógeno/química , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Animales , Western Blotting , Citometría de Flujo , Ratones , Ratones Endogámicos C57BL , Células RAW 264.7 , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Cicatrización de Heridas/efectos de los fármacos
20.
ACS Appl Mater Interfaces ; 11(31): 28377-28386, 2019 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-31251577

RESUMEN

The extracellular matrix (ECM) plays the role of a double-edged sword for controlling the differentiation of fibroblasts toward contractile myofibroblasts in the wound healing process. However, the exact structure-function relationship between ECM morphology and fibroblast behaviors still remains unclear. To better understand this relationship, herein, we designed and prepared a series of biocompatible polycaprolactone (PCL)-based fibers with different fiber diameters (nano vs micro) and different alignments (random vs aligned) using a simple electrospinning process, with a particular attention to the morphological effect of PCL fiber scaffolds on guiding fibroblast behaviors. Microfibers with the larger fiber diameters induce less cell spreading, adhesion, differentiation, and migration because of their lower surface tension. In contrast, nanofibers will retain fibroblast cells with typical spindle shapes and promote the expression of focal adhesion proteins through the integrin pathway. Furthermore, nanofibers upregulate the expression of α-smooth muscle actin (α-SMA), transforming growth factor, and vimentin filaments, indicating that the size change of the PCL fiber matrix from micrometers to nanometers indeed alters fibroblast differentiation to activate more α-SMA-expressed contractile myofibroblasts. Such a fiber size-dependent fibroblast behavior is largely attributed to the enhanced surface tension from the dressing matrix, which helps to promote the conversion of fibroblasts to myofibroblasts via either tissue regeneration or fibrosis. Therefore, this work further indicated that the rearrangement of collagen from nano-tropocollagen to micro-collagen bundles during the wound healing process can reverse fibroblasts to myofibroblasts from motivated to demise. This finding allows us to achieve the structural-based design of a new fibrous matrix for promoting wound healing and tissue regeneration.

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