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1.
Int J Biol Macromol ; 218: 1-8, 2022 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-35792312

RESUMO

Polycaprolactone (PCL) nanofibers have become an ideal material for bone tissue engineering due to a series of advantages. Considering the clinical treatment of bone defects, in addition to meeting the golden standard, PCL based nanofibers also need to be multifunctional to anti-inflammatory, antibacterial properties, and enhance the bone regeneration and repair. Herein, we successfully developed the multifunctional PCL/LIG/ZIF-8 composite nanofibers by loading ZIF-8 on electrospun PCL/lignin (PCL/LIG) nanofibers. The prepared composite nanofibers exhibit fairly good wettability and acceptable degradation rate, as well as excellent antioxidative stress and antibacterial properties originating from the incorporated LIG and loaded ZIF-8. Moreover, owing to the synergistic effect of LIG and ZIF-8, the composite nanofibers present excellent osteogenic differentiation, which can be verified in biomineralization experiments and real-time quantitative polymerase chain reaction. These results indicate that the PCL/LIG/ZIF-8 composite nanofibers, as potential healthcare candidate, have a promising applied in the treatment of bone defects.

2.
ACS Appl Mater Interfaces ; 13(43): 50836-50850, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34689546

RESUMO

Polyetheretherketone (PEEK) is a biocompatible polymer, but its clinical application is largely limited due to its inert surface. To solve this problem, a multifunctional PEEK implant is urgently fabricated. In this work, a dual-metal-organic framework (Zn-Mg-MOF74) coating is bonded to PEEK using a mussel-inspired polydopamine interlayer to prepare the coating, and then, dexamethasone (DEX) is loaded on the coating surface. The PEEK surface with the multifunctional coating provides superior hydrophilicity and favorable stability and forms an alkaline microenvironment when Mg2+, Zn2+, 2,5-dihydroxyterephthalic acid, and DEX are released due to the coating degradation. In vitro results showed that the multifunctional coating has strong antibacterial ability against both Escherichia coli and Staphylococcus aureus; it also improves human umbilical vein endothelial cell angiogenic ability and enhances rat bone marrow mesenchymal stem cell osteogenic differentiation activity. Furthermore, the in vivo rat subcutaneous infection model, chicken chorioallantoic membrane model, and rat femoral drilling model verify that the PEEK implant coated with the multifunctional coating has strong antibacterial and angiogenic ability and promotes the formation of new bone around the implant with a stronger bone-implant interface. Our findings indicate that DEX loaded on the Zn-Mg-MOF74 coating-modified PEEK implant with bacteriostasis, angiogenesis, and osteogenesis properties has great clinical application potential as bone graft materials.


Assuntos
Antibacterianos/farmacologia , Regeneração Óssea/efeitos dos fármacos , Estruturas Metalorgânicas/farmacologia , Neovascularização Patológica/tratamento farmacológico , Adsorção , Animais , Antibacterianos/síntese química , Antibacterianos/química , Benzofenonas/química , Benzofenonas/farmacologia , Dexametasona/química , Dexametasona/farmacologia , Escherichia coli/efeitos dos fármacos , Magnésio/química , Magnésio/farmacologia , Masculino , Estruturas Metalorgânicas/síntese química , Estruturas Metalorgânicas/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Neovascularização Patológica/microbiologia , Polímeros/química , Polímeros/farmacologia , Ratos , Ratos Sprague-Dawley , Staphylococcus aureus/efeitos dos fármacos , Zinco/química , Zinco/farmacologia
3.
Nanoscale Res Lett ; 16(1): 4, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33404823

RESUMO

Conductive and degradable nanofibrous scaffolds have great potential in promoting cell growth, proliferation, and differentiation under an external electric field. Although the issue of inferior electrical conductivity in body fluids still exists, polyaniline (PANI)-based degradable nanofibers can promote cell adhesion, growth, and proliferation. To investigate whether the effect is caused by the PANI morphology, we selected three inorganic acids as dopants in the process of PANI in situ oxidative polymerization: hydrochloric acid, sulfuric acid, and perchloric acid. The obtained polyaniline/polylactic acid (PANI/PLA) composite nanofibers were characterized via SEM, FTIR, and XPS analysis, and we confirmed that the PLA nanofibers were successfully coated by PANI without any change to the porous structure of the PLA nanofibers. The in vitro mechanical properties and degradability indicated that the oxidation of acid dopants should be considered and that it was likely to have a higher oxidation degradation effect on PLA nanofibers. The contact angle test demonstrated that PANI/PLA composite nanofibers with different surface morphologies have good wettability, implying that they meet the requirements of bone tissue engineering scaffolds. The surface roughness and cell viability demonstrated that different PANI morphologies on the surface can promote cell proliferation. The higher the surface roughness of the PANI, the better the biocompatibility. Consequently, the regulated surface morphology of PANI/PLA composite nanofibers via different acids doping has positive effect on biocompatibility in tissue engineering.

4.
J Hazard Mater ; 384: 121367, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31629589

RESUMO

Generally, the efficiency of water purification can be greatly increased by a high-flux membrane separation technology. One major challenge in the application of this technology is to achieve high removal efficacy of target pollutants with elevated water flux. Here we report a novel self-assembled composite by depositing two-dimensional MXene nanosheets on a commercialized mixed cellulose ester filter (as designated as MCM). Morphology study reveals that MCM exhibits an ultrathin flaked structure with uniform nanochannels which is stapled on a porous support. The tailored membrane has been successfully applied in the methylene blue solution treatment and 100% ± 0.1% removal rate is achieved while the feed concentration of dye solution is up to 90 mg·L-1. Concurrently, stable and comparatively elevated water flux was achieved, i.e., 28.94 ± 0.74 L·m-2·h-1, which is 1.88-fold of that of the commercialized UTC60 membrane. Further investigations on the separation mechanism are performed to get more insights into separation performance exhibited by MCM. It is found that the size-selective sieving, electrostatic repulsion of MXene and the high porosity of substrate play the synergistic effect on the fast and efficient dye removal behavior. Taken together, the composite membrane fabricated in present work provides an alternatively high-efficiency approach for dye treatment, and unflagging efforts will be further invested on the development and large-scale application of MXene-based membrane.

5.
Polymers (Basel) ; 11(6)2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31167368

RESUMO

CO2 has been regarded as one of the most promising blowing agents for polystyrene (PS) foam due to its non-flammability, low price, nontoxicity, and eco-friendliness. However, the low solubility and fast diffusivity of CO2 in PS hinder its potential applications. In this study, an attapulgite (ATP)/polypyrrole (PPy) nanocomposite was developed using the in situ polymerization method to generate the hierarchical cell texture for the PS foam based on the supercritical CO2 foaming. The results demonstrated that the nanocomposite could act as an efficient CO2 capturer enabling the random release of it during the foaming process. In contrast to the pure PS foam, the ATP/PPy nanocomposite reinforced PS foam is endowed with high cell density (up to 1.9 × 106) and similar thermal conductivity as the neat PS foam, as well as high compression modulus. Therefore, the in situ polymerized ATP/PPy nanocomposite makes supercritical CO2 foaming desired candidate to replace the widely used fluorocarbons and chlorofluorocarbons as PS blowing agents.

6.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 36(6): 776-8, 2005 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-16334550

RESUMO

OBJECTIVE: To investigate the expression of A-type atrial natriuretic peptide receptor (ANPR-A) in the kidneys of renovascular hypertension rats and evaluate the significance of the expression. METHODS: The rat model of renovascular hypertension was produced by constricting one lateral renal artery. After the renal artery being constricted for 4 weeks and 8 weeks, the systolic BP of rats was measured with a manometer using the tail-cuff method. Then, the expression of ANPR-A was respectively detected by immunohistochemical technique in the kidneys of the two-kidney, one-clip (2K1C) rats, and the expression level of ANPR-A was semi-quantitatively measured by Mias-2000 computer image analyzer. RESULTS: At 4 weeks after the artery-constricted operation,the expression of ANPR-A increased significantly in 2K1C hypertensive rat glomeruli and decreased significantly in renal tubules, compared with control (P<0.01), but there was no marked change in medullar collecting tubules. At 8 weeks after the artery-constricted operation, the expression of ANPR-A decreased significantly in 2K1C hypertensive rat renal tubules and medullar collecting tubules, compared with control (P<0.01); however, there was weak expression in glomeruli, and no statistically significant difference was seen when compared with control (P>0.05). CONCLUSION: The expression of ANPR-A decreased significantly in kidney tissues of renovascular


Assuntos
Hipertensão Renovascular/metabolismo , Rim/metabolismo , Receptores do Fator Natriurético Atrial/biossíntese , Animais , Fator Natriurético Atrial/metabolismo , Hipertensão Renovascular/etiologia , Masculino , Ratos , Ratos Sprague-Dawley , Receptores do Fator Natriurético Atrial/genética
7.
Zhongguo Zhong Yao Za Zhi ; 28(3): 259-62, 2003 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-15015316

RESUMO

OBJECTIVE: To investigate the influence of Shenfu injection on the hemodynamic indexes of myocardial ischemic dogs and blood pressure of dogs and rats. METHOD: Myocardial ischemic model was made and hypotension in the dogs was induced with ligating left front descending limb coronary artery method, and secondary hypertension by narrowing nephridium artery of rats, Shenfu injection was administered with 5, 10 mL.kg-1 to the above dogs and rats separately to investigate the influence of it on the hemodynamic indexes of myocardial ischemic dogs and blood pressure of rats. RESULT AND CONCLUSION: Shenfu injection enhanced the capacity of myocardial work markedly; it augmented the myocardium contractility and cardiac output without raising the oxygen consume, and at the same time it returned normal the blood pressure in myocardial ischemic; but it had no effects on the normal blood pressure and secondary hypertension of rats.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Isquemia Miocárdica/fisiopatologia , Plantas Medicinais , Aconitum/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Animais , Cães , Combinação de Medicamentos , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/isolamento & purificação , Ginsenosídeos/isolamento & purificação , Ginsenosídeos/farmacologia , Hemodinâmica/efeitos dos fármacos , Hipertensão/fisiopatologia , Injeções , Masculino , Panax/química , Plantas Medicinais/química , Ratos , Ratos Sprague-Dawley , Tetra-Hidroisoquinolinas/isolamento & purificação , Tetra-Hidroisoquinolinas/farmacologia
8.
Space Med Med Eng (Beijing) ; 15(5): 355-8, 2002 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-12449142

RESUMO

Objective. To study the influence of Ca2+ and Mg2+ on the enzymatic properties of cardiac muscle myosin. Method. A convenient method for the purification myosin from the left ventricle of rabbit heart was described. The Km and Vmax of Ca(2+)-activated and Mg(2+)-activated ATPase and the effects on the enzymatic properties of myosin ATPase in different ionic concentration and different pH range were determined from the rate of Pi release in enzymatic reaction. Result. The Km values of Ca2+, Mg(2+)-activated myosin ATPase at high ionic [correction of ironic] strength were 5.27 +/- 2.10 mmol, 7.04 +/- 2.06 mmol and the Vmax values were 1.10 +/- 0.13 micromoles mg-1 min-1, 0.617 +/- 0.09 micromoles mg-1 min-1 respectively. The Km of Ca(2+)-activated ATPase was higher than that of Mg(2+)-activated ATPase. But the ATPase activity of Ca2+ was influenced by the concentrations of MgCl2. The effect of Ca(2+)-activated ATPase increase was found at lower MgCl2 concentrations. As the MgCl2 concentration increased above 6 mmol/L, Ca2+ sensitivity was decreased. The pH-activity profiles showed that Mg(2+)-activated myosin ATPase activity was more stable than that of Ca(2+)-activated. Conclusion. The mechanism of Ca2+ and Mg2+ effect on myosin ATPase were different. Mg2+ is essential to maintain the conformation of enzymatic activity of myosin in cardiac muscle contraction. Ca2+ is likely acted as a role conducting signals and regulating function.


Assuntos
Cálcio/farmacologia , Cloreto de Magnésio/farmacologia , Magnésio/farmacologia , Miocárdio/enzimologia , Miosinas/metabolismo , Animais , ATPase de Ca(2+) e Mg(2+)/metabolismo , Cálcio/fisiologia , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Magnésio/fisiologia , Miosinas/efeitos dos fármacos , Coelhos
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