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1.
Int J Biol Macromol ; : 132517, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38777008

RESUMO

The rapid activation of phosphatidylinositol-specific phospholipase C (PI-PLC) occurs early after the stimulation of biotic and abiotic stress in plants, which directly associated with the calcium channel-induced calcium (Ca2+) influx. Exogenous calcium chloride (CaCl2) mediates the calcium signaling transduction to promote the γ-aminobutyric acid accumulation and nutritional quality in shredded carrots whereas the generation mechanism remains uncertain. Therefore, the involvement of PI-PLC-associated phospholipid metabolism was investigated in present study. Our result revealed that CaCl2 treatment promoted the expression and activity of PI-PLC and increased the inositol 1,4,5-trisphosphate and hexakisphosphate content in shredded carrots. The transcripts of multi-glutamate receptor-like channels (DcGLRs), the glutamate and γ-aminobutyric acid (GABA) content, and Ca2+ influx were induced by CaCl2 treatment in shredded carrots during storage. However, PI-PLC inhibitor (U73122) treatment inhibited the activation of PI-PLC, the increase of many DcGLRs family genes expression levels, and Ca2+ influx. Moreover, the identification of DcPI-PLC4/6 and DcGLRs proteins, along with the analysis of characteristic domains such as PLCXc, PLCYc, C2 domain, transmembranous regions, and ligand binding domain, suggests their involvement in phospholipid catalysis and calcium transport in carrots. Furthermore, DcPI-PLC4/6 overexpression in tobacco leaves induced the Ca2+ influx by activating the expressions of NtGLRs and the accumulation of glutamate and GABA. These findings collectively indicate that CaCl2 treatment-induced PI-PLC activation influences DcGLRs expression levels to mediate cytosolic Ca2+ influx, thus, highlighting the "PI-PLC-GLRs-Ca2+" pathway in calcium signaling generation and GABA biosynthesis in shredded carrots.

2.
Carbohydr Polym ; 334: 121934, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38553248

RESUMO

The development of highly effective chitosan-based hemostatic materials that can be utilized for deep wound hemostasis remains a considerable challenge. In this study, a hemostatic antibacterial chitosan/N-hydroxyethyl acrylamide (NHEMAA)/Ti3C2Tx (CSNT) composite cryogel was facilely prepared through the physical interactions between the three components and the spontaneous condensation of NHEMAA. Because of the formation of strong crosslinked network, the CSNT cryogel showed a developed pore structure (~ 99.07 %) and superfast water/blood-triggered shape recovery, enabling it to fill the wound after contacting the blood. Its capillary effect, amino groups, negative charges, and affinity with lipid collectively induced rapid hemostasis, which was confirmed by in vitro and in vivo analysis. In addition, CSNT cryogel showed excellent photothermal antibacterial activities, high biosafety, and in vivo wound healing ability. Furthermore, the presence of chitosan effectively prevented the oxidation of MXene, thus enabling the long-term storage of the MXene-reinforced cryogel. Thus, our hemostatic cryogel demonstrates promising potential for clinical application and commercialization, as it combines high resilience, rapid hemostasis, efficient sterilization, long-term storage, and easy mass production.


Assuntos
Quitosana , Hemostáticos , Nitritos , Elementos de Transição , Humanos , Acrilamida , Antibacterianos/farmacologia , Criogéis , Hemostasia , Hemostáticos/farmacologia
3.
Food Chem ; 448: 139126, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38555693

RESUMO

Uncontrolled antibacterial, insufficient barrier and low strength are the bottlenecks of food packaging applications. Herein, Ta4C3Tx nanosheet as a template was used to prepare Ta4C3Tx immobilized silver nanoparticles (Ta4C3Tx-AgNPs), which was compounded with nanocellulose to obtain high-strength and high barrier controllable bactericidal nanocellulose-based bioplastic packaging (CTa-Ag). The results indicated that due to the hydrogen bonding between nanocellulose and Ta4C3Tx, the bridging effect of QCS (quaternized chitosan) and the filling of Ta4C3Tx-AgNPs, the CTa-Ag had tightly stacked microstructure, which endowed them with excellent mechanical properties (4.0 GPa), ultra-low oxygen permeability (0.009 cm3/m2·d·atm) and stable photothermal conversion efficiency. Importantly, the packaging exhibits the ability to control the release of antibacterial active ingredients. Moreover, the synergistic effects of controllable release of nano active factors, photothermal and photocatalysis in CTa-Ag gave it long-lasting antibacterial properties. This study brings new insights into the design and manufacture of multifunctional, controllable and long-lasting antibacterial bioplastic food packaging.


Assuntos
Antibacterianos , Celulose , Embalagem de Alimentos , Nanopartículas Metálicas , Prata , Embalagem de Alimentos/instrumentação , Antibacterianos/química , Antibacterianos/farmacologia , Prata/química , Prata/farmacologia , Celulose/química , Nanopartículas Metálicas/química , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Quitosana/química
4.
Food Chem ; 446: 138866, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38430769

RESUMO

Fresh-cut potatoes are prone to surface browning and physiological degradation. Chlorogenic acid (CGA), a natural phenolic antioxidant, has demonstrated preservative properties in various postharvest products. However, the underlying mechanisms of its application on maintaining quality remain unclear. Therefore, the effect of exogenous CGA treatment on quality deterioration of potato slices and the mechanisms involved were investigated. Results revealed CGA treatment retarded the browning coloration, suppressed microbial growth and inhibited the declines in starch, and ascorbic acid contents in potato slices. Meanwhile, the treatment activated the phenylpropanoid pathway but decreased the activities of phenolic decomposition-related enzymes such as polyphenol oxidase (PPO) and tyrosinase and downregulated StPPO expression. Moreover, the treated slices exhibited reduced accumulation of reactive oxygen species and increased activity of antioxidant enzymes. Additionally, they displayed enhanced 2,2-diphenyl-1-picrylhydrazyl radicals scavenging capacity and higher ATP levels. Therefore, these findings indicated that CGA treatment was effective for quality maintenance and antioxidant capacity enhancement in fresh-cut potatoes, thereby providing potential strategies for the preservation and processing of fresh-cut produce.


Assuntos
Antioxidantes , Solanum tuberosum , Antioxidantes/metabolismo , Ácido Clorogênico/farmacologia , Ácido Clorogênico/metabolismo , Solanum tuberosum/metabolismo , Fenóis/metabolismo , Ácido Ascórbico/metabolismo , Catecol Oxidase/metabolismo
5.
Int J Biol Macromol ; 266(Pt 1): 131253, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38556240

RESUMO

Food packaging is an essential part of food transportation, storage and preservation. Biodegradable biopolymers are a significant direction for the future development of food packaging materials. As a natural biological polysaccharide, chitosan has been widely concerned by researchers in the field of food packaging due to its excellent film-forming property, good antibacterial property and designability. Thus, the application research of chitosan-based food packaging films, coatings and aerogels has been greatly developed. In this review, recent advances on chitosan-based food packaging materials are summarized. Firstly, the development background of chitosan-based packaging materials was described, and then chitosan itself was introduced. In addition, the design, preparation and applications of films, coatings and aerogels in chitosan-based packaging for food preservation were discussed, and the advantages and disadvantages of each research in the development of chitosan-based packaging materials were analyzed. Finally, the application prospects, challenges and suggestions for solving the problems of chitosan-based packaging are summarized and prospected.


Assuntos
Quitosana , Embalagem de Alimentos , Quitosana/química , Embalagem de Alimentos/métodos , Plásticos Biodegradáveis/química , Biopolímeros/química
6.
Int J Biol Macromol ; 260(Pt 1): 129489, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38242399

RESUMO

Effective control of wound bleeding and sustained promotion of wound healing remain a major challenge for hemostatic materials. In this study, the hemostatic sponge with controllable antibacterial and adjustable continuous promotion of wound healing (CMNCu) was prepared by chitosan, aminated MXene and copper ion. Interestingly, the internal topological point-line-surface interaction endowed the CMN-Cu sponge longitudinal staggered tubular porous microstructure, combined with the lipophilic properties obtained by modified MXene, which greatly improved its flexibility, wet elasticity and blood enrichment capacity. In addition, the sponge achieved controlled release of active ingredients, which made it present highly effective antibacterial activity and long-lasting ability to promote wound healing. In vitro and in vivo experiments confirmed that CMN-Cu sponge presented high-efficient hemostatic performance. Last but not least, a series of cell experiments showed that the CMN-Cu sponge had excellent safety as a hemostatic material.


Assuntos
Quitosana , Hemostáticos , Nitritos , Elementos de Transição , Hemostáticos/farmacologia , Hemostáticos/química , Quitosana/farmacologia , Quitosana/química , Cobre/farmacologia , Hemostasia , Cicatrização , Antibacterianos/farmacologia , Antibacterianos/química
7.
Plant Physiol Biochem ; 206: 108217, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38039581

RESUMO

The effect of calcium chloride (CaCl2) treatment on γ-aminobutyric acid (GABA) accumulation in fresh-cut cantaloupe and the involved mechanisms were investigated. The result showed that 1% (w/v) CaCl2 treatment increased GABA content and activities of glutamate decarboxylase (GAD) and succinate semialdehyde dehydrogenase (SSADH), while decreased glutamate (Glu) content and GABA transaminase (GABA-T) activities in fresh-cut cantaloupe. CmCML11 and CmCAMTA5 expressions of CaCl2-treated fruit increased by 187.4% and 165.6% than control fruit in the initial 6 h. Besides, expressions of GABA shunt genes, including CmGAD1, CmGAD2, CmGABA-T and CmSSADH were also up-regulated by CaCl2 treatment during early storage. Moreover, acting as a transcriptional activator, CmCAMTA5 could bind to the CG-box in promoters of CmGAD1, CmGABA-T and CmSSADH and activate their transcription. Furthermore, the interaction between CmCML11 and CmCAMTA5 could enhance the transcriptional activation on GABA shunt genes which were regulated by CmCAMTA5. Collectively, our findings revealed that CaCl2 treatment promoted GABA accumulation in fresh-cut cantaloupe via the combined effect of CmCML11 and CmCAMTA5 in the regulation of expressions of CmGAD1, CmGABA-T, and CmSSADH in GABA shunt.


Assuntos
Cucumis melo , Cucumis melo/genética , Cucumis melo/metabolismo , Cloreto de Cálcio , 4-Aminobutirato Transaminase/genética , 4-Aminobutirato Transaminase/metabolismo , Ácido gama-Aminobutírico/metabolismo , Ácido Glutâmico
8.
Carbohydr Polym ; 299: 120204, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36876815

RESUMO

Super strength and high barrier properties are the bottleneck of the application of cellulose film materials. Herein, it is reported a flexible gas barrier film with nacre-like layered structure, in which 1D TEMPO-oxidized nanocellulose (TNF) and 2D MXene self-assembled to form an interwoven stack structure with 0D AgNPs filling the void space. The strong interaction and dense structure endowed TNF/MX/AgNPs film with mechanical properties far superior to PE films and acid-base stability. Importantly, the film presented ultra-low oxygen permeability confirmed by molecular dynamics simulations and better barrier properties to volatile organic gases than PE films. It is here considered the tortuous path diffusion mechanism of the composite film responsible for the enhanced gas barrier performance. The TNF/MX/AgNPs film also possessed antibacterial properties, biocompatibility and degradability (completely degraded after 150 days in soil). Collectively, the TNF/MX/AgNPs film brings innovative insights into the design and fabrication of high-performance materials.

9.
Front Oncol ; 12: 939021, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35978819

RESUMO

Gefitinib has shown promising efficacy in the treatment of patients with locally advanced or metastatic EGFR-mutated non-small cell lung cancer (NSCLC). Molecular biomarkers for gefitinib metabolism-related lncRNAs have not yet been elucidated. Here, we downloaded relevant genes and matched them to relevant lncRNAs. We then used univariate, LASSO, and multivariate regression to screen for significant genes to construct prognostic models. We investigated TME and drug sensitivity by risk score data. All lncRNAs with differential expression were selected for GO/KEGG analysis. Imvigor210 cohort was used to validate the value of the prognostic model. Finally, we performed a stemness indices difference analysis. lncRNA-constructed prognostic models were significant in the high-risk and low-risk subgroups. Immune pathways were identified in both groups at low risk. The higher the risk score the greater the value of exclusion, MDSC, and CAF. PRRophetic algorithm screened a total of 58 compounds. In conclusion, the prognostic model we constructed can accurately predict OS in NSCLC patients. Two groups of low-risk immune pathways are beneficial to patients. Gefitinib metabolism was again validated to be related to cytochrome P450 and lipid metabolism. Finally, drugs that might be used to treat NSCLC patients were screened.

10.
ACS Nano ; 15(12): 18880-18894, 2021 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-34870416

RESUMO

The rapid development of consumer electronics, artificial intelligence, and clinical medicine generates an increasing demand for flexible pressure sensors, whose performance depends significantly on sensitive materials with high flexibility and proper conductivity. MXene, a type of 2D nanomaterial, has attracted extensive attention due to its good electrical conductivity, hydrophilicity, and flexibility. The synthesis methods for MXenes make it relatively easy to control their microstructure and surface termination groups. Hence, MXenes can obtain peculiar microstructures and facilely combine with other functional materials, making them promising prospects for use in flexible pressure sensors. In this Review, recent advances in MXenes are summarized, mainly focusing on the synthesis methods and their application in flexible pressure sensors. Finally, the challenges and potential solutions for future development are also discussed.


Assuntos
Nanoestruturas , Titânio , Inteligência Artificial , Condutividade Elétrica , Eletrônica
11.
Carbohydr Polym ; 273: 118545, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34560957

RESUMO

Food packaging systems with a single function of freshness keeping or monitoring may not be able to meet all practical needs. Herein, cellulose nanofibers (CNF)-based labels with dual functions of fruit freshness keeping and visual monitoring were prepared by coaxial 3D printing. CNF-based ink with blueberry anthocyanin was used to create the shell of fibers, exhibiting high formability and print fidelity as well as sensitive visual pH-responsiveness for freshness monitoring. Chitosan containing 1-methylcyclopropene (1-MCP) was loaded into the hollow microchannels of fibers, in which 1-MCP was trapped by the electrostatic effect of chitosan and CNF and exhibited a sustained release behavior. The 3D printed labels prolonged the shelf life of litchis for 6 days, meanwhile, they sensitively indicated the changes in freshness and the accuracy was confirmed by Headspace-Gas Chromatography-Ion Mobility Spectrometry. The CNF-based integrated labels developed in this work provided a new idea for the development of food intelligent packaging.

12.
Front Immunol ; 12: 682435, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34194437

RESUMO

Cancer immunotherapy is a kind of therapy that can control and eliminate tumors by restarting and maintaining the tumor-immune cycle and restoring the body's normal anti-tumor immune response. Although immunotherapy has great potential, it is currently only applicable to patients with certain types of tumors, such as melanoma, lung cancer, and cancer with high mutation load and microsatellite instability, and even in these types of tumors, immunotherapy is not effective for all patients. In order to enhance the effectiveness of tumor immunotherapy, this article reviews the research progress of tumor microenvironment immunotherapy, and studies the mechanism of stimulating and mobilizing immune system to enhance anti-tumor immunity. In this review, we focused on immunotherapy against tumor microenvironment (TME) and discussed the important research progress. TME is the environment for the survival and development of tumor cells, which is composed of cell components and non-cell components; immunotherapy for TME by stimulating or mobilizing the immune system of the body, enhancing the anti-tumor immunity. The checkpoint inhibitors can effectively block the inhibitory immunoregulation, indirectly strengthen the anti-tumor immune response and improve the effect of immunotherapy. We also found the checkpoint inhibitors have brought great changes to the treatment model of advanced tumors, but the clinical treatment results show great individual differences. Based on the close attention to the future development trend of immunotherapy, this study summarized the latest progress of immunotherapy and pointed out a new direction. To study the mechanism of stimulating and mobilizing the immune system to enhance anti-tumor immunity can provide new opportunities for cancer treatment, expand the clinical application scope and effective population of cancer immunotherapy, and improve the survival rate of cancer patients.


Assuntos
Suscetibilidade a Doenças , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Imunidade , Neoplasias/etiologia , Neoplasias/metabolismo , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/metabolismo , Biomarcadores , Terapia Combinada , Gerenciamento Clínico , Suscetibilidade a Doenças/imunologia , Humanos , Imunofenotipagem , Terapia de Alvo Molecular , Mutação , Neoplasias/patologia , Neoplasias/terapia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Resultado do Tratamento , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
13.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200653

RESUMO

Cushioning and antibacterial packaging are the requirements of the storage and transportation of fruits and vegetables, which are essential for reducing the irreversible quality loss during the process. Herein, the composite of carboxymethyl nanocellulose, glycerin, and acrylamide derivatives acted as the shell and chitosan/AgNPs were immobilized in the core by using coaxial 3D-printing technology. Thus, the 3D-printed cushioning-antibacterial dual-function packaging aerogel with a shell-core structure (CNGA/C-AgNPs) was obtained. The CNGA/C-AgNPs packaging aerogel had good cushioning and resilience performance, and the average compression resilience rate was more than 90%. Although AgNPs was slowly released, CNGA/C-AgNPs packaging aerogel had an obvious antibacterial effect on E. coli and S. aureus. Moreover, the CNGA/C-AgNPs packaging aerogel was biodegradable. Due to the customization capabilities of 3D-printing technology, the prepared packaging aerogel can be adapted to more application scenarios by accurately designing and regulating the microstructure of aerogels, which provides a new idea for the development of food intelligent packaging.


Assuntos
Antibacterianos/química , Celulose/química , Embalagem de Alimentos/métodos , Géis/química , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Quitosana/química , Escherichia coli/efeitos dos fármacos , Impressão Tridimensional , Prata/química , Staphylococcus aureus/efeitos dos fármacos
14.
Food Chem ; 363: 130342, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34144414

RESUMO

The cumulative toxicity of AgNPs has limited their application in food packaging. As such, the quest for AgNPs should focus on controlling their release to reduce the cumulative toxicity. Here, two kinds of green hydrothermal carbonized methods were used to treat sulfhydryl-modified chitosan to obtain two kinds of carbon spheres/AgNPs (Glutinous rice sesameballs-like AgNPs-SMCS and dragon fruit-like SMCS-Ag), which exhibited good stability and high immobilization efficiency for AgNPs, and the release of total Ag from AgNPs-SMCS and SMCS-Ag were only about 5.63% and 3.59% after 14 days, respectively. Subsequently, they were added into chitosan separately to prepare chitosan-based films. Two carbon spheres/AgNPs regulated the microstructure of chitosan-based films because of the electrostatic interaction and the micro-nanometer filling behavior, thus further immobilized the AgNPs. Importantly, the films presented good antibacterial activity and excellent safety. These results will provide a theoretical basis for the green and safe design of AgNPs antibacterial agent.


Assuntos
Quitosana , Nanopartículas Metálicas , Antibacterianos , Carbono , Prata
15.
Biomed Pharmacother ; 138: 111450, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33690088

RESUMO

Lung cancer is one of the common malignant tumors that threaten human life with serious incidence and high mortality. According to the histopathological characteristics, lung cancer is mainly divided into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC accounts for about 80-85% of lung cancers. In fact, lung cancer metastasis is a major cause of treatment failure in clinical patients. The underlying reason is that the mechanisms of lung cancer metastasis are still not fully understood. The metastasis of lung cancer cells is controlled by many factors, including the interaction of various components in the lung cancer microenvironment, epithelial-mesenchymal transition (EMT) transformation, and metastasis of cancer cells through blood vessels and lymphatics. The molecular relationships are even more intricate. Further study on the mechanisms of lung cancer metastasis and in search of effective therapeutic targets can bring more reference directions for clinical drug research and development. This paper focuses on the factors affecting lung cancer metastasis and connects with related molecular mechanisms of the lung cancer metastasis and mechanisms of lung cancer to specific organs, which mainly reviews the latest research progress of NSCLC metastasis. Besides, in this paper, experimental models of lung cancer and metastasis, mechanisms in SCLC transfer and the challenges about clinical management of lung cancer are also discussed. The review is intended to provide reference value for the future research in this field and promising treatment clues for clinical patients.


Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/genética , Metástase Neoplásica/tratamento farmacológico , Metástase Neoplásica/patologia , Microambiente Tumoral/fisiologia
16.
Mater Sci Eng C Mater Biol Appl ; 113: 111012, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32487414

RESUMO

Silver nanoparticles (AgNPs) have been widely used for sterilization due to their broad-spectrum bactericidal properties. However, there exist the problems of premature releasing and accumulative toxicity when free AgNPs are applied. This study proposed a one-pot hydrothermal strategy to synthesize carbon spheres immobilized silver nanoparticles (AgNPs@CS). The synthesis involves with silver ammonia solution as Ag precursor, and corn stalk as green reducing agent and carbon precursor. Furthermore, AgNPs@CS was anchored by cellulose nanofibers (CNF) to obtain the antibacterial composite paper. The obtained CNF/AgNPs@CS paper exhibited superior antibacterial properties against E. coli and S. aureus. Notably, the accumulative release rate of AgNPs from AgNPs@CS was 10.2% in 9 days, while that from CNF/AgNPs@CS paper was only 6.7% due to the anchoring effect of both CS and CNF, which was low for avoiding the cumulative toxicity problem. In addition, the mechanical and barrier properties of CNF/AgNPs@CS paper were also improved by 29.4% (tensile index), 2.7% (tear index), 7.4% (burst index), 10% (folding endurance), 0.8% (water vapor transmission) and 9.4% (oxygen transmission rate), respectively. Therefore, the composite paper has potential application as a medical antibacterial material.


Assuntos
Antibacterianos/química , Carbono/química , Nanocompostos/química , Prata/química , Zea mays/química , Animais , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Celulose/química , Escherichia coli/efeitos dos fármacos , Química Verde , Nanopartículas Metálicas/química , Camundongos , Testes de Sensibilidade Microbiana , Nanocompostos/toxicidade , Nanofibras/química , Papel , Staphylococcus aureus/efeitos dos fármacos , Resistência à Tração , Zea mays/metabolismo
17.
ACS Appl Mater Interfaces ; 12(18): 20307-20320, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32298570

RESUMO

Wound bleeding and infection are two of the major threats to patients' lives, but developing safe materials with high hemostasis efficiency and antibacterial activity remains a major challenge. Silver nanoparticles (AgNPs) are suitable as antibacterial agents in the hemostatic process, but the application is hampered because of easy accumulation of toxicity. Herein, thiol-modified chitosan (TMC) was prepared by modifying with mercaptosuccinic acid and then was used to immobilize AgNPs to obtain composite sponges (TMC/AgNPs) for stemming the bleeding and preventing infection. TMC/AgNPs sponges had complex interlaced tubular porous structure with high porosity (99.42%), indicating high absorption. TMC had high immobilization efficiency for AgNPs-the release rate of AgNPs was 14.35% after 14 days-but the TMC/AgNPs sponge still had excellent antibacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. In vitro and in vivo experiments confirm that the TMC/AgNPs sponge had fast and efficient hemostatic performance in comparison with the PVF sponge, and its possible mechanism was the synergistic effect of high blood absorption capacity and the interaction between amino, sulfydryl, and blood cells. Furthermore, the TMC/AgNPs sponge can promote wound healing by preventing wound infection, while the PVF sponge cannot. More importantly, the sponges had good safety due to the immobilization of TMC for AgNPs.


Assuntos
Antibacterianos/uso terapêutico , Quitosana/análogos & derivados , Quitosana/uso terapêutico , Hemostáticos/uso terapêutico , Nanopartículas Metálicas/uso terapêutico , Prata/uso terapêutico , Animais , Antibacterianos/toxicidade , Coagulação Sanguínea/efeitos dos fármacos , Quitosana/toxicidade , Escherichia coli/efeitos dos fármacos , Hemostáticos/toxicidade , Masculino , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Camundongos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Coelhos , Prata/química , Prata/toxicidade , Staphylococcus aureus/efeitos dos fármacos , Tampões de Gaze Cirúrgicos , Cicatrização/efeitos dos fármacos
18.
Carbohydr Polym ; 224: 115197, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472838

RESUMO

In order to obtain new retention and drainage-aid agent, exfoliated xylan-g-QCS/MMT nanocomposites were prepared. Briefly, quaternized chitosan azide (QCS-N3) was intercalated into the layer of montmorillonite (MMT) to enlarge the interplanar gallery; subsequently, QCS-N3/MMT was grafted with xylan by click chemistry, during this process, the interlayer space of MMT was further increased till exfoliated. Subsequently, the exfoliated xylan-g-QCS/MMT was evaluated to act as retention and drainage-aid agent. The initial critical concentration of xylan-g-QCS/MMT was 0.01 mg/g in the adsorption behavior on cellulosic substrate. The maximum flocculation efficiency for CaCO3 was 37.41%. When dosages were about 0.01 mg/g, oSR values were the lowest. All these results show that retention and drainage-aid performance of xylan-g-QCS/MMT was better than only xylan, QCS or MMT. The study combined three kinds of natural resources to prepare organic/inorganic nanocomposites, providing a new method to develop papermaking additive and achieve high-value utilization of natural resources.

19.
Food Chem ; 295: 16-25, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174745

RESUMO

The instability of Laurel essential oil (LEO) and easy leakage of silver nanoparticle (AgNP) restricts their application in food field. To control their release, liposomes were used to encapsulate LEO and AgNPs (Lip-LEO-AgNPs), and mixed with chitosan to coat polyethylene (PE) films (PC-Lip/LEO/AgNPs) to package pork. The results show that only about 29.30% of LEO and 11.79% of AgNPs were released from the liposome after 7 days at 25 °C. Nevertheless, Lip-LEO-AgNPs showed good antioxidant properties. Moreover, PC-Lip/LEO/AgNPs films had good antimicrobial activity. Evaluation tests on pork indicate that PC-Lip/LEO/AgNPs films could keep the quality of pork at 4 °C for 15 days while pure PE film only kept it for 9 days, and that the coating films had no cytotoxicity. PC-Lip/LEO/AgNPs films exhibited significant combined action in functional packaging to extend storage period, and provided a new idea for the application of LEO and AgNPs in food.


Assuntos
Conservação de Alimentos/métodos , Lipossomos/química , Óleos Voláteis/química , Carne Vermelha , Sesquiterpenos/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Quitosana/química , Qualidade dos Alimentos , Armazenamento de Alimentos/métodos , Humanos , Lipossomos/farmacologia , Nanopartículas Metálicas/química , Óleos Voláteis/farmacologia , Tamanho da Partícula , Sesquiterpenos/farmacologia , Prata/química , Suínos , Temperatura
20.
Carbohydr Polym ; 216: 119-128, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31047048

RESUMO

As a kind of potential absorbent, polysaccharide materials are limited due to weak stability, low absorption and recovery rate. Herein, a novel composite adsorbent - the magnetic composite gel beads (CMC/SA/graphene oxide@Fe3O4) were prepared by combining carboxymethyl chitosan (CMC), sodium alginate (SA) with graphene oxide@Fe3O4, and then utilized for the adsorption of Cu2+, Cd2+ and Pb2+ from the wastewater. The physicochemical property of CMC/SA/graphene oxide@Fe3O4 beads were characterized in detail. The CMC/SA/graphene oxide@Fe3O4 magnetic gel beads could separate easily from the wastewater and showed a higher stability due to the addition of graphene oxide@Fe3O4. The adsorption experiments show that the adsorption of Cu2+, Cd2+ and Pb2+ on the magnetic gel bead was well fitted with pseudo-second-order model and Langmuir isotherm model, and the maximum adsorption capacity of Cu2+, Cd2+ and Pb2+ reached 55.96, 86.28 and 189.04 mg/g, respectively. Moreover, the magnetic gel beads had selective adsorption toward Pb2+. In addition, the magnetic gel beads still obtained 90% of the adsorption rates after five cycles, and showed good adsorption efficiency in the simulated real environment. This work proves that the CMC/SA/graphene oxide@Fe3O4 magnetic gel beads as the adsorbents have promising potential in wastewater treatment.


Assuntos
Alginatos/química , Quitosana/análogos & derivados , Óxido Ferroso-Férrico/química , Géis/química , Grafite/química , Metais Pesados/química , Adsorção , Cádmio/química , Quitosana/química , Cobre/química , Óxido Ferroso-Férrico/síntese química , Géis/síntese química , Grafite/síntese química , Química Verde/métodos , Substâncias Húmicas , Chumbo/química , Fenômenos Magnéticos , Termodinâmica , Purificação da Água/métodos
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