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1.
Int J Biol Macromol ; 154: 758-764, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32171832

RESUMO

Alkali/urea, a green dissolution system for chitosan, have been widely used in preparation of chitosan-derived materials. However, there are no related reports detail the structure stability and biocompatibility of chitosan in alkali/urea, which are important for its large-scale application. In this work, chitosan was dissolved in KOH/urea solution and stored at different temperature for different time. The structure, viscosity, molecule weight (Mw), degree of deacetylation (DD), and biocompatibility of chitosan were determined. The Mw of chitosan decreased from 1011 KDa to 827-834 KDa, and DD increased from 76.9% to 85.7-93.5% after been stored at 25 °C and 4 °C for 5 weeks. Incomplete dissolution of chitosan and increase of DD enhanced its thermal stability by forming new crystallization zone. In contrast, chitosan stored in -20 °C for 5 weeks was stable without obvious change of Mw and DD. Moreover, the processed chitosans were no-toxic and safety for the biomedicine applications.

2.
Carbohydr Polym ; 229: 115557, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826433

RESUMO

Chitosan (CS) based self-assembled nanohydrogels are considered as promising platform for biomedicine, petrochemical, agricultural and food applications due to their unique biodegradability, nano-interface effect, and intelligent responsiveness. However, the most CS derivatives are prepared in heterogeneous system, which is unstable and environmentally unfriendly. In this work, a series of hydroxybutyl chitosan (HBC) was synthesized based on a green and homogeneous system (potassium hydroxide (KOH)/urea), which given this derivative interesting temperature responsive phase transformation behavior. HBC could change from dissolved state into nanohydrogel state in deionized water, when the temperature exceed its critical phase change temperature, and this process could be repeated more than 50 cycles (one cycle/day) without coagulation. The nanohydrogels solution exhibited concentration and temperature-dependent ultraviolet absorption and visible light regulation, which had great application potential in smart windows. This study provided a novel preparation method and extended the application of chitosan-based temperature responsive self-assembled nanohydrogels.

3.
Int J Biol Macromol ; 146: 99-109, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31874265

RESUMO

Biocompatibility and mechanical properties have always been important indicators for the application of hydrogel materials in tissue engineering. In this work, a high strength and toughness chitosan-poly (vinyl alcohol) (PVA) DN (double network) hydrogel based on multiple hydrogen bonding interactions was prepared by applying the simple freezing-heating alternate treatment to the chitosan-PVA alkaline solution. The PVA first network was prepared by freeze crystallization, and the chitosan second network was constructed by raising the chitosan/KOH/urea temperature to 45 °C. The dynamic hydrogen bonding presented in the first PVA network and the second chitosan network given the hydrogel superior compressive (60%-230 KPa), tensile (152 KPa-360%), recoverability (90.77% after 5 cycles) and anti-swelling properties. The results of in vitro cell compatibility and in vivo subcutaneous implantation in rats both indicated that the chitosan-PVA DN hydrogel had the ability to promote cell attachment and wound healing. This DN hydrogel based on hydrogen bonding is expected to be applied in the tissue engineering repair. In addition, the hydrogel preparation process is simple and non-toxic, which provides a reference for the production of green and safe tissue engineering hydrogels.

4.
PLoS One ; 14(12): e0226599, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31860684

RESUMO

The MADS-box gene family encodes transcription factors with many biological functions that extensively regulate plant growth, development and reproduction. Erigeron breviscapus is a medicinal herb used widely in traditional Chinese medicine, and is believed to improve blood circulation and ameliorate platelet coagulation. In order to gain a detailed understanding of how transcription factor expression may regulate the growth of this potentially important medicinal plant, a genome-wide analysis of the MADS-box gene family of E. breviscapus is needed. In the present study, 44 MADS-box genes were identified in E. breviscapus and categorized into five subgroups (MIKC, Mα, Mß, Mγ and Mδ) according to their phylogenetic relationships with the Arabidopsis MADS-box genes. Additionally, the functional domain, subcellular location and motif compositions of the E. breviscapus MADS-box gene products were characterized. The expression levels for each of the E. breviscapus MADS-box (EbMADS) genes were analyzed in flower, leaf, stem and root organs, and showed that the majority of EbMADS genes were expressed in flowers. Meanwhile, some MADS genes were found to express high levels in leaf, stem and root, indicating that the MADS-box genes are involved in various aspects of the physiological and developmental processes of the E. breviscapus. The results from gene expression analysis under different pollination treatments revealed that the MADS-box genes were highly expressed after non-pollinated treatment. To the best of our knowledge, this study describes the first genome-wide analysis of the E. breviscapus MADS-box gene family, and the results provide valuable information for understanding of the classification, cloning and putative functions of the MADS-box family.


Assuntos
Erigeron/genética , Perfilação da Expressão Gênica/métodos , Proteínas de Domínio MADS/genética , Sequenciamento Completo do Genoma/métodos , Evolução Molecular , Flores/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/química , Família Multigênica , Filogenia , Folhas de Planta/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Caules de Planta/genética , Plantas Medicinais , Domínios Proteicos
5.
EBioMedicine ; 49: 106-117, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31668570

RESUMO

BACKGROUND: KRAS mutations are the most frequent oncogenic aberration in lung adenocarcinoma. KRAS mutant isoforms differentially shape tumour biology and influence drug responses. This heterogeneity challenges the development of effective therapies for patients with KRAS-driven non-small cell lung cancer (NSCLC). METHODS: We developed an integrative pharmacogenomics analysis to identify potential drug targets to overcome MEK/ERK inhibitor resistance in lung cancer cell lines with KRAS(G12C) mutation (n = 12). We validated our predictive in silico results with in vitro models using gene knockdown, pharmacological target inhibition and reporter assays. FINDINGS: Our computational analysis identifies casein kinase 2A1 (CSNK2A1) as a mediator of MEK/ERK inhibitor resistance in KRAS(G12C) mutant lung cancer cells. CSNK2A1 knockdown reduces cell proliferation, inhibits Wnt/ß-catenin signalling and increases the anti-proliferative effect of MEK inhibition selectively in KRAS(G12C) mutant lung cancer cells. The specific CK2-inhibitor silmitasertib phenocopies the CSNK2A1 knockdown effect and sensitizes KRAS(G12C) mutant cells to MEK inhibition. INTERPRETATION: Our study supports the importance of accurate patient stratification and rational drug combinations to gain benefit from MEK inhibition in patients with KRAS mutant NSCLC. We develop a genotype-based strategy that identifies CK2 as a promising co-target in KRAS(G12C) mutant NSCLC by using available pharmacogenomics gene expression datasets. This approach is applicable to other oncogene driven cancers. FUND: This work was supported by grants from the National Natural Science Foundation of China, the National Key Research and Development Program of China, the Lung Cancer Research Foundation and a Mildred-Scheel postdoctoral fellowship from the German Cancer Aid Foundation.

6.
Carbohydr Polym ; 224: 115176, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472871

RESUMO

Weak mechanical properties, lack biocompatibility and relatively bioinert are formidable obstruct in application of bone repair materials. Multifunctional composite materials have been considered as a viable solution to this problem. Here, a new double network (DN) hydrogel was constructed by physical cross-linking of medical grade poly (vinyl alcohol) (PVA) and chitosan in KOH/urea dissolution system. The obtained hydrogel demonstrated excellent tensile strength (0.24 MPa), elongation at break (286%), and high compressive strength (0.11 MPa on the strain of 60%). Our studies showed that the prepared hydrogel had excellent biocompatibility in vitro and the introduction of hydroxyapatite (HAp) by surface mineralization imparted hydrogel the ability to induce rat bone marrow stem cells (rBMSCs) differentiation. The in vivo experiments revealed that the surface mineralized double network hydrogel significantly accelerated simultaneous regeneration of bone defects in a rabbit bone defect model. All the results indicated that this hydrogel has the potential as a bone repair material.


Assuntos
Osso e Ossos/efeitos dos fármacos , Quitosana/química , Hidrogéis/química , Hidrogéis/farmacologia , Minerais/química , Álcool de Polivinil/química , Adsorção , Animais , Osso e Ossos/citologia , Osso e Ossos/fisiologia , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Força Compressiva , Hidróxidos/química , Osteogênese/efeitos dos fármacos , Compostos de Potássio/química , Coelhos , Soroalbumina Bovina/química , Propriedades de Superfície , Resistência à Tração , Engenharia Tecidual , Ureia/química
7.
Int J Biol Macromol ; 138: 321-333, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31295499

RESUMO

The aim of this study was to develop an effective wound dressing using a temperature-responsive hydroxybutyl chitosan (HBC) based hydrogel. The HBC - chitosan (CS) - dopamine (HCS-DOPA) composite hydrogels were prepared by the dopamine self-polymerization at different concentrations (0, 0.5, 1.0 and 2.0 mg/mL), termed as HCS, HCS-DOPA-0.5, HCS-DOPA-1 and HCS-DOPA-2, respectively. The gelling characteristic of HBC hydrogel was not influenced by composite CS and DOPA. The HCS-DOPA composite hydrogels were non-cytotoxic to mouse fibroblast cells (L929), and induced under 5.0% hemolysis rate. In vitro antibacterial studies, composite HCS-DOPA-2 hydrogels exhibited lasting inhibition to S. aureus >8 h. The whole blood test in vitro demonstrated that blood clotting time treated with HCS-DOPA-2 composite hydrogels was shortened to 95.6 s compared with that of HCS in vitro hemostasis. The results suggested that HCS-DOPA-2 composite hydrogels could be applied as a promising wound dressing for hemostasis in vitro.


Assuntos
Bivalves , Quitosana/química , Hemostasia/efeitos dos fármacos , Hidrogéis/química , Hidrogéis/farmacologia , Indóis/química , Polímeros/química , Temperatura Ambiente , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Fenômenos Químicos , Escherichia coli/efeitos dos fármacos , Cinética , Staphylococcus aureus/efeitos dos fármacos
8.
Int J Biol Macromol ; 132: 1090-1097, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902715

RESUMO

We have designed microcapsules-immobilized composite capsules and evaluated the oral delivery efficacy. The composite capsules were developed by encapsulating Perinereis aibuhitensis extract (PaE), a model substance possessing antioxidant activity, loaded gum Arabic/gelatin microcapsules in calcium alginate (CA) hydrogel (PaE:CA/GA/GE-CCs). In vitro antioxidant assay showed the obtained composite capsules were able to protect PaE from gastric acid, since O2- scavenging rate of encapsulated PaE was about 1.8 folds as that of free PaE after 5 h incubation in simulated gastrointestinal fluid. Moreover, in vivo study showed that after the treatment of oral administration for 30 days, the mice of PaE:CA/GA/GE-CCs group suffered significantly lower oxidative stress level than those of other groups, illustrated as higher SOD and catalase activity, as well as lower malondialdehyde content in liver cells. The results demonstrated the composite capsules could concentrate PaE in small intestine, and enhance the absorption efficiency and in vivo efficacy.


Assuntos
Alginatos/química , Antioxidantes/administração & dosagem , Antioxidantes/química , Portadores de Fármacos/química , Gelatina/química , Goma Arábica/química , Hidrogéis/química , Administração Oral , Animais , Antioxidantes/farmacologia , Cápsulas , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/toxicidade , Teste de Materiais , Camundongos , Estresse Oxidativo/efeitos dos fármacos
9.
Contrast Media Mol Imaging ; 2019: 2783519, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30804723

RESUMO

Vascular cell adhesion molecule-1 (VCAM-1) can be a promising target for colitis study because of its critical role in inflammation development. Single-chain variable fragment (scFv) antibody presents fast blood clearance when served as an imaging probe. We applied the probe of 99mTc-scFv-VCAM-1 to colitis rabbit to examine its imaging performance. The colitis model rabbit was prepared, and a typical inflammatory lesion was confirmed in the colon. The probe of 99mTc-scFv-VCAM-1 was synthesized and injected into the model animal before imaging examination. Scintigraphy detected colitis lesions in both SPECT planar and SPECT/CT fused images, with higher target-to-nontarget ratios in the model group (2.71 ± 0.31) than those in the control group (1.12 ± 0.10). Biodistribution study determined tracer uptake in different organs, and autoradiography (ARG) confirmed probe accumulation in colon lesions. The uptake ratio of the model colon to the control colon was 4.71 ± 0.61 in quantitative analysis of the ARG regions of interest. Stronger VCAM-1 expression in the model colon than that in the control colon was confirmed by western blotting and immunohistochemistry. Our imaging study indicates molecular imaging with scFv-VCAM-1 as a promising way for inflammatory bowel disease diagnosis and evaluation.


Assuntos
Colite/metabolismo , Sondas Moleculares , Molécula 1 de Adesão de Célula Vascular/imunologia , Animais , Autorradiografia , Western Blotting , Colite/diagnóstico por imagem , Colite/imunologia , Imuno-Histoquímica , Masculino , Coelhos , Anticorpos de Cadeia Única , Tomografia Computadorizada de Emissão de Fóton Único , Molécula 1 de Adesão de Célula Vascular/metabolismo
10.
Int J Biol Macromol ; 125: 78-86, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30529347

RESUMO

Cell therapy with bone marrow-derived mesenchymal stem cells (BMSCs) is a potential method for many disease treatments, including keloid. In the present study, an Arg-Gly-Asp (RGD) modified hydroxybutyl chitosan (HBC) hydrogel (HBC-RGD) was developed to enhance the adhesion and proliferation of BMSCs within the hydrogel. The successful synthesis of HBC-RGD was confirmed by FTIR and 1H NMR. Both HBC and HBC-RGD hydrogel had desired thermosensitivity, biocompatibility and enzymatic degradability in vitro. Compared with HBC hydrogel, HBC-RGD hydrogel was more beneficial for the adhesion and proliferation of BMSCs. Furthermore, the BMSCs incorporated HBC-RGD (BMSCs/HBC-RGD) hydrogel could inhibit the proliferation of keloid fibroblasts (Kfs) and suppress the nodular collagenous fibers of keloid tissue. These results suggested that the HBC-RGD hydrogel could be applied as a potential 3D hydrogel scaffold for cell culture, and BMSCs/HBC-RGD hydrogel was potential to be applied for keloid therapy with subcutaneous in-situ injection in the future.


Assuntos
Quitosana/análogos & derivados , Hidrogéis/química , Células-Tronco Mesenquimais/citologia , Oligopeptídeos/química , Tecidos Suporte/química , Materiais Biocompatíveis , Quitosana/química , Fibroblastos/metabolismo , Hemólise , Humanos , Hidrogéis/síntese química , Queloide/tratamento farmacológico , Teste de Materiais , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Reologia , Análise Espectral
11.
Int J Biol Macromol ; 120(Pt A): 1103-1110, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30170054

RESUMO

The novel solvent (0.25 M KOH/0.01 M urea alkaline solution) was used to successfully dissolve chitosan without freezing-thawing cycles, for the first time. The results from XRD, FTIR, and 13CNRM proved that KOH/urea solution could destroy the hydrogen bonds between chitosan chains more efficiently than NaOH/urea solution. The dynamic light scattering, rheology, viscosity and elemental analysis confirmed that the KOH/urea hydrogen-bonded chitosan complex had a better thermal stability at 40 °C, and no obvious deacetylation and degradation appeared in dissolution process. Subsequently, the homogeneous chemical modification of chitosan based on KOH/urea dissolution system solution was conducted at 25 °C. The FTIR and microscopic observation indicated that the carboxymethyl chitosan, N,N,N-trimethyl chitosan and hydroxyl butyl chitosan were synthetized successfully. This work provided a green and stable solvent for homogeneous chemical modification of chitosan.


Assuntos
Quitosana/análogos & derivados , Quitosana/química , Hidróxidos/química , Compostos de Potássio/química , Ureia/química , Quitosana/síntese química , Ligações de Hidrogênio , Radical Hidroxila/química , Espectroscopia de Ressonância Magnética , Reologia , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade , Água/química
12.
Int J Biol Macromol ; 120(Pt A): 152-158, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30092308

RESUMO

The aim of this study was to develop an effective cell sheet translocation method using a cell adhesive and temperature-responsive hydroxybutyl chitosan hydrogel (HBC). The polydopamine (PD)-coated HBC hydrogels were prepared by the dopamine self-polymerization on the surface of HBC hydrogel with different coating time, termed as P30, P60 and P120, respectively. Gelling property of HBC was not affected by PD coating. The PD-coated HBC hydrogels promoted the attachment and proliferation of mouse fibroblast cells (L929) and human umbilical vein endothelial cells (HUVECs), and allowed formation of monolayer cell sheet. In vitro translocation of HUVECs sheet could be obtained successively through phase transition of PD coated HBC hydrogel from gel to sol, and the cells sheet transferred from P30 hydrogel to a round cell coverglass maintained relatively complete monolayer and normal cell morphology. The results showed that P30 hydrogel has the potential to be used for cell transplantation therapy.


Assuntos
Células Imobilizadas , Quitosana/análogos & derivados , Células Endoteliais da Veia Umbilical Humana , Hidrogéis/química , Indóis/química , Polímeros/química , Animais , Células Imobilizadas/metabolismo , Células Imobilizadas/transplante , Quitosana/química , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/transplante , Humanos , Camundongos
13.
World J Microbiol Biotechnol ; 34(2): 35, 2018 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-29427255

RESUMO

The High osmolarity glycerol (HOG) gene family plays crucial roles in various developmental and physiological processes in fungi, such as the permeability of cell membrane, chlamydospore formation and stress signaling. Although the function of HOG genes has been investigated in Saccharomyces cerevisiae and some filamentous fungi, a comprehensive analysis of HOG gene family has not been performed in Aspergillus oryzae, a fungi mainly used for the production of soy sauce. In this study, we identified and corrected a total of 90 HOG genes from the A. oryzae genome. According to the phylogenetic relationship, they were divided into four discrete groups (Group A-D) comprising of 16, 24, 30 and 20 proteins, respectively. Six conserved motifs and exon-intron structures were examined among all HOG proteins to reveal the diversity of AoHOG genes. Based on transcriptome technology, the expression patterns of AoHOG genes across all developmental stages was identified, suggesting that the AoHOG gene family mainly functions in the logarithmic phase of development. The expression profiles of AoHOG genes under different concentrations of salt stress indicated that AoHOG genes are extensively involved in salt stress response, with possibly different mechanisms. The genome-wide identification, evolutionary, gene structures and expression analyses of AoHOG genes provide a comprehensive overview of this gene family as well as their potential involvements in development and stress responses. Our results will facilitate further research on HOG gene family regarding their physiological and biochemical functions.


Assuntos
Aspergillus oryzae/genética , Perfilação da Expressão Gênica , Genes Fúngicos/genética , Estudo de Associação Genômica Ampla , Glicerol/metabolismo , Aspergillus oryzae/fisiologia , Evolução Molecular , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Genoma Fúngico , Concentração Osmolar , Pressão Osmótica , Filogenia , Tolerância ao Sal , Transdução de Sinais , Estresse Fisiológico , Transcriptoma
14.
Macromol Biosci ; 18(3)2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29369479

RESUMO

A series of thermo/pH sensitive N-succinyl hydroxybutyl chitosan (NSHBC) hydrogels with different substitution degrees of succinyl are prepared for drug delivery. Rheology analysis shows that the gelation temperature of NSHBC hydrogels is 3.8 °C higher than that of hydroxybutyl chitosan (HBC) hydrogels. A model drug bovine serum albumin (BSA) is successfully loaded and released. NSHBC hydrogels show excellent pH sensitivity drug release behaviors. After incubation for 24 h, 93.7% of BSA is released from NSHBC hydrogels in phosphate buffer saline (PBS) (pH 7.4), which is significantly greater than that of 24.6% at pH 3.0. In contrast, the release rate of BSA from HBC is about 70.0% at pH 3.0 and 7.4. Thus, these novel hydrogels have the prominent merits of high adaptability to soluble drugs and pH sensitivity triggered release, indicating that NSHBC hydrogels have promising applications in oral drug delivery.


Assuntos
Quitosana/química , Sistemas de Liberação de Medicamentos , Hidrogéis/química , Ácido Succínico/química , Administração Oral , Quitosana/análise , Concentração de Íons de Hidrogênio , Reologia
15.
Carbohydr Polym ; 184: 154-163, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29352906

RESUMO

In this work, a composite sponge was produced by physically mixing hydroxybutyl chitosan with chitosan to form a porous spongy material through vacuum freeze-drying. Hydrophilic and macroporous composite hydroxybutyl chitosan sponge was developed via the incorporation of chitosan into hydroxybutyl chitosan. The composite sponge showed higher porosity (about 85%), greater water absorption (about 25 times), better softness and lower blood-clotting index (BCI) than those of chitosan sponge and hydroxybutyl chitosan sponge. The composite sponge with good hydrophilic could absorb the moisture in the blood to increase blood concentration and viscosity, and become a semi-swelling viscous colloid to clog the capillaries. Cytocompatibility tests with L929 cells and HUVEC cells demonstrated that composite sponge were no cytotoxicity, and could promote the growth of fibroblasts. It made up for the shortcomings of hydroxybutyl chitosan with unfavorable antibacterial effect to achieve a higher level of antibacterial (>99.99% reduction). Eventually, the vivo evaluations in Sprague-Dawley rats revealed that epithelial cells attached to the composite sponge and penetrated into the interior, in addition to this, it was also proved that the composite sponge (HC-1) had a better ability to promote wound healing and helped for faster formation of skin glands and re-epithelialization. The obtained data encourage the use of this composite sponge for wound dressings.


Assuntos
Quitosana/análogos & derivados , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/uso terapêutico , Bandagens , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Quitosana/uso terapêutico , Masculino , Camundongos , Coelhos , Ratos , Ratos Sprague-Dawley , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Int J Biol Macromol ; 107(Pt A): 463-469, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28887187

RESUMO

The hemostatic properties of surface modified chitosan nonwoven had been investigated. The succinyl groups, carboxymethyl groups and quaternary ammonium groups were introduced into the surface of chitosan nonwoven (obtained NSCS, CMCS and TMCS nonwoven, respectively). For blood clotting, absorbance value (0.105±0.03) of NSCS1 nonwoven was the smallest (CS 0.307±0.002, NSCS2 0.148±0.002, CMCS1 0.195±0.02, CMCS2 0.233±0.001, TMCS1 0.191±0.002, TMCS2 0.345±0.002), which indicated the stronger hemostatic potential. For platelet aggregation, adenosine diphosphate agonist was added to induce the nonwoven to adhered platelets. The aggregation of platelet with TMCS2 nonwoven was highest (10.97±0.16%). Further research of blood coagulation mechanism was discussed, which indicated NSCS and CMCS nonwoven could activate the intrinsic pathway of coagulation to accelerate blood coagulation. NSCS1 nonwoven showed the shortest hemostatic time (147±3.7s) and the lowest blood loss (0.23±0.05g) in a rabbit ear artery injury model. These results demonstrated that these surface modified chitosan nonwoven dressings could use as a promising hemostatic intervention, especially NSCS nonwoven dressing.


Assuntos
Bandagens , Quitosana/química , Hemorragia/prevenção & controle , Agregação Plaquetária/efeitos dos fármacos , Difosfato de Adenosina/agonistas , Difosfato de Adenosina/química , Compostos de Amônio/química , Animais , Coagulação Sanguínea/efeitos dos fármacos , Quitosana/administração & dosagem , Hemorragia/patologia , Hemostáticos/administração & dosagem , Hemostáticos/química , Humanos , Adesividade Plaquetária/efeitos dos fármacos , Coelhos , Siloxanas/química , Propriedades de Superfície
17.
ChemSusChem ; 10(23): 4715-4724, 2017 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-28926196

RESUMO

A new strategy was developed to simultaneously produce two important chemicals, namely, methallyl alcohol (Mol) and diethyl acetal (Dal) from methacrolein in ethanol solvent at low temperature with the use of Beta zeolites modified by tin (Sn-ß catalysts). All the Sn-ß catalysts were prepared by the solid-state ion-exchange method, wherein the calcination step was conducted under different gas atmospheres. The catalyst precalcined in Ar (Sn-ß-Ar) had a reduced number of extra-framework Sn species and enabled more Sn species to be exchanged into the framework as isolated tetrahedral SnIV , enhancing the catalytic activity of the Meerwein-Ponndorf-Verley (MPV) reaction. The sodium-exchanged Sn-ß-Ar, with a reduced number of weak Brønsted acid sites, led to an even better selectivity for Mol, owing to the restriction of the side reactions such as acetalization, addition, and etherification. Under optimized catalyst and reaction conditions, the yield of Mol and Dal reached approximately 90 % and 96 %, respectively. The possible reaction pathways, along with a complex network of side products, was proposed after a detailed investigation through the use of different substrates as reactants. The fine-tuning of Sn-ß catalysts through different treatments discussed in this work is of great significance toward the understanding and manipulation of complex reactions between α,ß-unsaturated aldehydes and primary alcohols.

18.
Food Funct ; 8(10): 3533-3541, 2017 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-28875196

RESUMO

In this work, a thermal and wide pH range (from 1 to 13) stable biological agent was extracted from Perinereis aibuhitensis (P. aibuhitensis), and the antithrombotic activity of this P. aibuhitensis extract (PaE) was investigated. In vitro antithrombotic activity test indicated that PaE could significantly extend the clotting time of recalcified rabbit blood: the clotting time of the 10 mg mL-1, 20 mg mL-1 and 40 mg mL-1 PaE groups increased by 24.24%, 68.64% and 130.76%, respectively. Further platelet poor plasma (PPP) coagulation study proved that PaE could obviously inhibit the intrinsic coagulation pathway and slightly inhibit the extrinsic coagulation pathway. Moreover, PaE could effectively inhibit fibrinogen turning into fibrin induced by thrombin. More importantly, PaE exhibited thermal stability, since P. aibuhitensis was boiled in the PaE preparation process, as well as tolerance to strong acid and alkali, since its fibrinogen inhibition activity was retained after treatment with a wide range of pH value conditions. Finally, the antithrombotic activity ingredients in PaE were preliminarily identified, the results of which indicated that the ingredients were ethanol insoluble, insensitive to papain and pepsin, and could be degraded by H2O2. Additionally, we demonstrated that PaE at a concentration of not more than 20 mg mL-1, the concentration at which PaE showed high anticoagulant activity, exhibited favorable biocompatibility via in vitro hemolysis rate test and MTT assay. In summary, the results evidenced that this conveniently prepared and stable PaE was a safe and effective antithrombotic agent, and had the potential to be utilized for antithrombotic food development.


Assuntos
Fibrinolíticos/química , Fibrinolíticos/isolamento & purificação , Poliquetos/química , Animais , Coagulação Sanguínea/efeitos dos fármacos , Fibrinogênio/metabolismo , Concentração de Íons de Hidrogênio , Coelhos , Temperatura Ambiente , Trombina/metabolismo
19.
J Huazhong Univ Sci Technolog Med Sci ; 37(4): 582-586, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28786065

RESUMO

This study aimed to examine the diagnosis performance of 99mTc-methoxyisobutylisonitrisonitrile (99mTc-MIBI) and multimodality imaging [ultrasound, single-photon emission computed tomography/computed tomography (SPECT/CT)] for hyperparathyroidism (HPT). From Nov. 2009 to Dec. 2015, clinical data of a total of 43 HPT patients (16 males and 27 females; 26-70 years old, average age: 51.60±10.66 years old) were retrospectively analyzed. Among them, 19 patients with primary hyperparathyroidism (PHPT) underwent 99mTc-MIBI planar imaging, 24 [15 with PHPT and 9 with secondary hyperparathyroidism (SHPT)] underwent SPECT/CT hybrid imaging, and 41 (33 with PHPT and 8 with SHPT) had neck ultrasound imaging. Final diagnosis was determined by pathological examination after surgery. The positive rate was compared between different imaging modalities, and the correlation analysis was conducted between imaging results and lesion size or serum parathyroid hormone (PTH) level. The results showed that the total positive rates of 99mTc-MIBI imaging, ultrasound, and the two combined imaging in the 43 HPT cases were 90.70% (39/43), 58.54% (24/41), and 100% (41/41), respectively. According to lesion numbers, the positive rates were 79.10% (53/67), 53.23% (33/62), and 88.71% (55/62), respectively. SPECT/CT hybrid images were positive in all the 24 patients who underwent this examination. The mean maximum diameters of the lesions in 99mTc-MIBI positive and negative patients were 1.96±0.95 cm and 1.36±0.67 cm respectively, with statistically significant difference noted (P=0.03). The T/NT of 99mTc-MIBI imaging at the early phase was correlated positively with serum PTH level (r=0.40, P=0.01). The T/NT of 99mTc-MIBI imaging at both the early phase and the delay phase was correlated positively with lesion size (r=0.51, and r=0.45, respectively; P<0.01 for both). It was concluded that 99mTc-MIBI imaging presents significant value for location diagnosis of HPT, especially when combined with SPECT/CT hybrid imaging or ultrasound. The 99mTc-MIBI uptake correlates positively with serum PTH level and lesion size.


Assuntos
Hiperparatireoidismo Primário/diagnóstico por imagem , Imagem Multimodal , Tecnécio Tc 99m Sestamibi/química , Adulto , Idoso , Feminino , Humanos , Hiperparatireoidismo Primário/patologia , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/metabolismo
20.
Int J Biol Macromol ; 105(Pt 1): 924-930, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28736041

RESUMO

Multilayer alginate hydrogel beads (MAHBs), which were prepared by emulsion method, had been fabricated via the ionic crosslinking between calcium ion (Ca2+) and carboxylic group of alginate and utilized as encapsulating material for oral delivery of a model probiotic bacteria Bifidobacterium breve. Optical and fluorescence microscopy obviously showed the microorganism cells were encapsulated in the core beads. The viability of B. breve cells encapsulated in MAHBs was significantly enhanced compared with ordinary free cultured ones, the top CFU per mL were (3.70±0.20)×107 and (2.61±0.22)×107 respectively. Meanwhile, B. breve cells encapsulated in MAHBs could still keep viability even after 12h' culture in the broth with pH value similar to gastric juice, while the free cultured cells had no activity in such culture condition. To test applicability of MAHBs for the delivery of microorganisms, a Gram-positive strain, Staphylococcus aureus, as well as a Gram-negative strain, Escherichia coli, were also employed and encapsulated in MAHBs. Similar to B. breve cells, the viability of encapsulated S. aureus cells and E. coli cells in extreme pH value environment were significantly promoted. In addition, a high α-amylase yielding efficiency Bacillus subtilis strain was found and encapsulated in MAHBs. Compared with control groups, MAHBs encapsulated B. subtilis cells produced more α-amylase after 240h' culture, while the release of this enzyme was sustained rather than the burst release like free cultured group, which means this system would not reduce metabolite yield while having long term sustained-release effect. In summary, MAHBs are favorable biological carrier, which has the potential of being applied to oral delivery of probiotics.


Assuntos
Alginatos/química , Portadores de Fármacos/química , Hidrogéis/química , Microesferas , Probióticos/química , Administração Oral , Bacillus subtilis/química , Bacillus subtilis/citologia , Bacillus subtilis/metabolismo , Fermentação , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio , Probióticos/metabolismo
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