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1.
Sci Rep ; 11(1): 1544, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33452372

RESUMO

Soil microbe is crucial to a healthy soil, therefore its diversities and abundances under different conditions are still need fully understand.The aims of the study were to characterize the community structure and diversity of microbe in the rhizosphere soil after continuous maize seed production, and the relationship between the disease incidence of four diseases and the variation of the rhizosphere microbe. The results showed that different fungal and bacterial species were predominant in different cropping year, and long-term maize seed production had a huge impact on structure and diversity of soil microbial. Ascomycota and Mortierellomycota were the dominant fungal phyla and Mortierella and Ascomycetes represented for a large proportion of genus. A relative increase of Fusarium and Gibberella and a relative decrease of Mortierella, Chrysosporium, Podospora, and Chaetomium were observed with the increase of cropping year. Pathogenic Fusarium, Curvularia, Curvularia-lunata, Cladosporium, Gibberella-baccata, and Plectosphaerellaceae were over-presented and varied at different continuous cropping year, led to different maize disease incidence. Proteobacteria and Actinobacteria ranked in the top two of all bacterial phyla, and genus Pseudarthrobacter, Roseiflexus and RB41 dominated top 3. Haliangium and Streptomyces decreased with the continuous cropping year and mono-cropping of maize seed production increased disease incidence with the increase of cropping year, while the major disease was different. Continuous cropping of maize seed production induced the decrease of protective microbe and biocontrol genera, while pathogenic pathogen increased, and maize are in danger of pathogen invasion. Field management show great effects on soil microbial community.

2.
Mater Sci Eng C Mater Biol Appl ; 119: 111613, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33321656

RESUMO

Construction of biomimetic microenvironment is vital to understand the relationship between matrix mechanical cues and cell fate, as well as to explore potential tissue engineering scaffolds for clinical application. In this study, through the enzymatic mineralizable collagen hydrogel system, we established the biomimetic bone matrix which was capable of realizing mechanical regulation independent of mineralization by incorporation of phosphorylated molecules (vinylphosphonic acid, VAP). Then, based on the biomimetic mineralized matrix with same composition but significantly different mechanical stiffness, we further investigated the effect of matrix stiffness on osteogenic differentiation of bone marrow stromal cells (BMSCs). The results clearly demonstrated that biomimetic mineralized microenvironment with higher mechanical strength promoted osteogenic differentiation of BMSCs. Further mechanism analysis demonstrated that the mineralized hydrogel with higher stiffness promoted cytoskeletal assembly, which enhanced the expression and nuclear colocalization of YAP and RUNX2, thereby promoted the osteogenic differentiation of stem cells. This study supplies a promising material platform not only for bone tissue engineering but also for exploring the mechanism of biomimetic bone matrix mechanics on osteogenesis.

3.
Regen Biomater ; 7(5): 505-514, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33149939

RESUMO

Various surface bioactivation technology has been confirmed to improve the osteogenic ability of porous titanium (pTi) implants effectively. In this study, a three-layered composite coating, i.e. outer layer of hydroxyapatite (HA), middle layer of loose titanium dioxide (L-TiO2) and inner layer of dense TiO2 (D-TiO2), was fabricated on pTi by a combined processing procedure of pickling, alkali heat (AH), anodic oxidation (AO), electrochemical deposition (ED) and hydrothermal treatment (HT). After soaking in simulated body fluid for 48 h, the surface of the AHAOEDHT-treated pTi was completely covered by a homogeneous apatite layer. Using MC3T3-E1 pro-osteoblasts as cell model, the cell culture revealed that both the pTi without surface treatment and the AHAOEDHT sample could support the attachment, growth and proliferation of the cells. Compared to the pTi sample, the AHAOEDHT one induced higher expressions of osteogenesis-related genes in the cells, including alkaline phosphatase, Type I collagen, osteopontin, osteoclast inhibitor, osteocalcin and zinc finger structure transcription factor. As thus, besides the good corrosion resistance, the HA/L-TiO2/D-TiO2-coated pTi had good osteogenic activity, showing good potential in practical application for bone defect repair.

4.
Nanoscale ; 2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33241829

RESUMO

Weak osteogenic activity affects the long-term fixation and lifespan of titanium (Ti) implants. Surface modification along with a built-in porous structure is a highly considerable approach to improve the osteoinduction and osseointegration capacity of Ti. Herein, the osteoinduction and osteogenic activities of electrochemically deposited (ED) nanoplate-like, nanorod-like and nanoneedle-like hydroxyapatite (HA) coatings (named EDHA-P, EDHA-R, and EDHA-N, respectively) were evaluated in vitro and in vivo by comparison with those of acid/alkali (AA) treatment. The results revealed that the apatite forming ability of all nanostructured EDHA coatings was excellent, and only 12 h of soaking in SBF was needed to induce a complete layer of apatite. More serum proteins adsorbed on EDHA-P than others. In cellular experiments, different from those on EDHA-R and EDHA-N, the cells on EDHA-P presented a polygonal shape with lamellipodia extension, and thus exhibited a relatively larger spreading area. Furthermore, EDHA-P was more favorable for the enhancement of the proliferation and ALP activity of BMSCs, and the up-regulation of OPN gene expression. Based on the good biological performance in vitro, EDHA-P was selected to further evaluate its osteoinduction and osteogenic activities in vivo by comparison with AA treatment. Interestingly, a greater ability of ectopic osteoinduction was observed in the EDHA-P group compared to that in the AA group. At the osseous site, EDHA-P promoted more bone on/ingrowth, and had a higher area percentage of newly formed bone in the bone-implant interface and inner pores of the implants than in the AA group. Thus, a nanoplate-like HA coating has good potential in improving the osteoinductivity and osteogenic activity of porous Ti implants in clinical applications.

5.
Int J Nanomedicine ; 15: 6605-6618, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982221

RESUMO

Purpose: The aim of research is to fabricate nanostructured hydroxyapatite (HA) coatings on the titanium via electrochemical deposition (ED). Additionally, the biological properties of the ED-produced HA (EDHA) coatings with a plate-like nanostructure were evaluated in vitro and in vivo by undertaking comparisons with those prepared by acid/alkali (AA) treatment and by plasma spray-produced HA (PSHA) nanotopography-free coatings. Materials and Methods: Nanoplate-like HA coatings were prepared through ED, and nanotopography-free PSHA coatings were fabricated. The surface morphology, phase composition, roughness, and wettability of these samples were investigated. Furthermore, the growth, proliferation, and osteogenic differentiation of MC3T3-E1 cells cultured on each sample were evaluated via in vitro experiments. Histological assessment and push-out tests for the bone-implant interface were performed to explore the effect of the EDHA coatings on the interfacial osseointegration in vivo. Results: XRD analysis showed that the strongest intensity for the EDHA coatings was at the (002) plane rather than at the regular (211) plane. Relatively higher surface roughness and greater wettability were observed for the EDHA coatings. Cellular experiments revealed that the plate-like nanostructured EDHA coatings not only possessed an ability, similar to that of PSHA coatings, to promote the adhesion and proliferation of MC3T3-E1 cells but also demonstrated significantly enhanced early or intermediate markers of osteogenic differentiation. Significant osseointegration enhancement in the early stage of implantation period and great bonding strength were observed at the interface of bone and EDHA samples. In comparison, relatively weak osseointegration and bonding strength of the bone-implant interface were observed for the AA treatment. Conclusion: The biological performance of the plate-like nanostructured EDHA coating, which was comparable with that of the PSHA, improves early-stage osteogenic differentiation and osseointegration abilities and has great potential for enhancing the initial stability and long-term survival of uncemented or 3D porous titanium implants.

6.
Int J Nanomedicine ; 15: 4171-4189, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606671

RESUMO

Background: Angiogenic and osteogenic activities are two major problems with biomedical titanium (Ti) and other orthopedic implants used to repair large bone defects. Purpose: The aim of this study is to prepare hydroxyapatite (HA) coatings on the surface of Ti by using electrochemical deposition (ED), and to evaluate the effects of nanotopography and silicon (Si) doping on the angiogenic and osteogenic activities of the coating in vitro. Materials and Methods: HA coating and Si-doped HA (HS) coatings with varying nanotopographies were fabricated using two ED modes, ie, the pulsive current (PC) and cyclic voltammetry (CV) methods. The coatings were characterized through scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometer (XPS), and atomic force microscopy (AFM), and their in vitro bioactivity and protein adsorption were assessed. Using MC3T3-E1 pre-osteoblasts and HUVECs as cell models, the osteogenic and angiogenic capabilities of the coatings were evaluated through in vitro cellular experiments. Results: By controlling Si content in ~0.8 wt.%, the coatings resulting from the PC mode (HA-PC and HS-PC) and CV mode (HA-CV and HS-CV) had nanosheet and nanorod topographies, respectively. At lower crystallinity, higher ionic dissolution, smaller contact angle, higher surface roughness, and more negative zeta potential, the HS and PC samples exhibited quicker apatite deposition and higher BSA adsorption capacity. The in vitro cell study showed that Si doping was more favorable for enhancing the viability of the MC3T3-E1 cells, but nanosheet coating increased the area for cell spreading. Of the four coatings, HS-PC with Si doping and nanosheet topography exhibited the best effect in terms of up-regulating the expressions of the osteogenic genes (ALP, Col-I, OSX, OPN and OCN) in the MC3T3-E1 cells. Moreover, all leach liquors of the surface-coated Ti disks promoted the growth of the HUVECs, and the HS samples played a more significant role in promoting cell migration and tube formation than the HA samples. Of the four leach liquors, only the two HS samples up-regulated NO content and expressions of the angiogenesis-related genes (VEGF, bFGF and eNOS) in the HUVECs, and the HS-PC yielded a better effect. Conclusion: The results show that Si doping while regulating the topography of the coating can help enhance the bone regeneration and vascularization of HA-coated Ti implants.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Durapatita/farmacologia , Nanopartículas/química , Osteogênese , Próteses e Implantes , Silício/química , Titânio/farmacologia , Adsorção , Animais , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Camundongos , Nanopartículas/ultraestrutura , Nanotubos/química , Neovascularização Fisiológica/efeitos dos fármacos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Soroalbumina Bovina/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios X
7.
ACS Appl Mater Interfaces ; 11(25): 22152-22163, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31194504

RESUMO

Natural nerve tissue is composed of nerve bundles with multiple aligned assembles, and matrix electroconductivity is beneficial to the transmission of intercellular electrical signals, or effectively deliver external electrical cues to cells. Herein, aiming at the biomimetic design of the extracellular matrix for neurons, we first synthesized electroconductive polypyrrole (PPy) nanoparticles with modified hydrophilicity to improve their uniformity in collagen hydrogel. Next, cell-laden collagen-PPy hybrid hydrogel microfibers with highly oriented microstructures were fabricated via a microfluidic chip. The hydrogel microfibers formed a biomimetic three-dimensional microenvironment for neurons, resulting from the native cell adhesion domains, oriented fibrous structures, and conductivity. The oriented fibrous microstructures enhanced neuron-like cells aligning with fibers' axon; the matrix conductivity improved cell extension and upregulated neural-related gene expression; moreover, external electrical stimulation further promoted the neuronal functional expression. This mechanism was attributed to the electroconductive matrix and its delivered electrical stimulation to cells synergistically upregulated the expression of an L-type voltage-gated calcium channel, resulting in an increase in the intracellular calcium level, which in turn promoted neurogenesis. This approach has potential in constructing the biomimetic microenvironment for neurogenesis.


Assuntos
Hidrogéis/química , Nanopartículas/química , Neurogênese/fisiologia , Animais , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Colágeno Tipo I/química , Condutividade Elétrica , Imunofluorescência , Neurogênese/genética , Células PC12 , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Água/química
8.
Biomaterials ; 147: 133-144, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28942129

RESUMO

Adequate bone regeneration has been difficult to achieve at segmental bone defects caused by disease. The surface structure and phase composition of calcium phosphate bioceramic are crucial for its bioactivity and osteoinductivity. In the present study, biphasic calcium phosphate (BCP) bioceramics composed of micro-whiskers and nanoparticles hybrid-structured surface (hBCP) were fabricated via a hydrothermal reaction. The in vivo long bone defect model of beagle dogs implanted with hBCP bioceramics achieved a higher quality regenerated bone as compared to the traditional smooth-surface BCP control group. After a 12-week implantation period, more new bone formation within the implanted material and a higher fracture load were observed in the hBCP group (p < 0.05 vs. control). In addition, the local bone integration efficacy, as determined by nanoindentation, showed a significantly closer elastic modulus of the implanted hBCP bioceramics to that of the natural bone adjacent. Finally, in vitro gene microarray analysis of the mesenchymal stem cells (MSCs) co-cultured with two bioceramics showed that the hBCP group induced a drastic downregulation of the genes associated with inflammatory response, which was never documented in previous studies regarding biomaterials with a micro/nano hybrid structure. The tumor necrosis factor (TNF) signalling pathway was the most involved and preferentially inhibited by the hBCP material. Collectively, the findings suggested that the micro/nano hybrid-structured bioceramics augmented local bone regeneration at segmental bone defects and presented a potential alternative to autologous bone grafts.


Assuntos
Materiais Biocompatíveis/química , Regeneração Óssea , Cerâmica/química , Hidroxiapatitas/química , Células-Tronco Mesenquimais/imunologia , Nanoestruturas/química , Animais , Substitutos Ósseos , Diferenciação Celular , Células Cultivadas , Cerâmica/toxicidade , Cães , Perfilação da Expressão Gênica , Hidroxiapatitas/toxicidade , Masculino , Fenômenos Mecânicos , Células-Tronco Mesenquimais/metabolismo , Osteogênese , Transdução de Sinais , Propriedades de Superfície , Fator de Necrose Tumoral alfa/metabolismo
9.
Mater Sci Eng C Mater Biol Appl ; 70(Pt 2): 1192-1199, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27772721

RESUMO

Biomedical porous titanium (Ti) scaffolds were fabricated by an improved polymeric sponge replication method. The unique formulations and distinct processing techniques, i.e. a mixture of water and ethanol as solvent, multiple coatings with different viscosities of the Ti slurries and centrifugation for removing the extra slurries were used in the present study. The optimized porous Ti scaffolds had uniform porous structure and completely interconnected macropores (~365.1µm). In addition, two different sizes of micropores (~45.4 and ~6.2µm) were also formed in the skeleton of the scaffold. The addition of ethanol to the Ti slurry increased the compressive strength of the scaffold by improving the compactness of the skeleton. A compressive strength of 83.6±4.0MPa was achieved for a porous Ti scaffold with a porosity of 66.4±1.8%. Our cellular study also revealed that the scaffolds could support the growth and proliferation of mesenchymal stem cells (MSCs).


Assuntos
Polímeros/farmacologia , Poríferos/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Titânio/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Força Compressiva/efeitos dos fármacos , Etanol/análise , Células-Tronco Mesenquimais/citologia , Álcool de Polivinil/análise , Porosidade , Coelhos , Estresse Mecânico , Viscosidade
10.
Mater Sci Eng C Mater Biol Appl ; 70(Pt 2): 1047-1056, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27772704

RESUMO

A simple approach to fabricating hydroxyxapatite/titanium dioxide (HA/TiO2) coating on porous titanium (Ti) scaffolds was developed in the present study. Surface TiO2 layer was firstly formed on porous Ti scaffolds with multi-scale pores by acid-alkali (AA) treatment. The outer HA layer was then formed on the TiO2 layer by subsequent pulse electrochemical deposition (ED) technique. All the three main process parameters, i.e. deposition times, current density and mass transfer mode affected the properties of the HA coating notably. Under the conditions of 90 deposition cycles, -10mA/cm2 of pulse current density and stirring, a thin layer of homogeneous and nanorod-like HA sediments was formed on the substrate surface of porous Ti scaffolds. The results of protein adsorption and cellular experiments showed that compared to the single TiO2 surface, the HA/TiO2 surface allowed more adsorption of serum proteins and further enhanced the alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts.


Assuntos
Materiais Revestidos Biocompatíveis/farmacologia , Durapatita/farmacologia , Tecidos Suporte/química , Titânio/farmacologia , Ácidos/química , Adsorção , Álcalis/química , Fosfatase Alcalina/metabolismo , Animais , Proteínas Sanguíneas/metabolismo , Linhagem Celular , Materiais Revestidos Biocompatíveis/química , Durapatita/química , Eletricidade , Eletroquímica , Camundongos , Osteocalcina/metabolismo , Porosidade , Titânio/química , Difração de Raios X
11.
Environ Sci Pollut Res Int ; 21(12): 7586-95, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24604271

RESUMO

To evaluate the effects of manure application on continuous maize seed production, 10-year cattle manure on soil properties, heavy metal in soil and plant were evaluated and investigated in calcareous soil. Results showed that manure application increased soil organic matter, total and available nutrients, pH, and electrical conductivity (EC), and the most massive rate caused the highest increase. Manure application led to an increase in exchangeable fraction and an increase of availability of heavy metal. Residual fraction was dominant among all metals, followed by the fraction bound to Fe and Mn oxides. Manure application involved accumulation of heavy metal on corn, but the accumulation in the stem is higher than that in the seed. Manure application led to a high deficiency of total Zn and high accumulation of total Cd in the soil of corn seed production, which should be a risk for safety seed production in calcareous soil in Northwest China.


Assuntos
Esterco , Metais Pesados/análise , Caules de Planta/química , Sementes/química , Poluentes do Solo/análise , Zea mays , Agricultura , Animais , Bovinos , China , Condutividade Elétrica , Fertilizantes , Concentração de Íons de Hidrogênio
12.
J Mater Sci Mater Med ; 23(9): 2267-79, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22639153

RESUMO

The network structure of a three-dimensional hydrogel scaffold dominates its performance such as mechanical strength, mass transport capacity, degradation rate and subsequent cellular behavior. The hydrogels scaffolds with interpenetrating polymeric network (IPN) structure have an advantage over the individual component gels and could simulate partly the structure of native extracellular matrix of cartilage tissue. In this study, to develop perfect cartilage tissue engineering scaffolds, IPN hydrogels of collagen/chondroitin sulfate/hyaluronan were prepared via two simultaneous processes of collagen self-assembly and cross linking polymerization of chondroitin sulfate-methacrylate (CSMA) and hyaluronic acid-methacrylate. The degradation rate, swelling performance and compressive modulus of IPN hydrogels could be adjusted by varying the degree of methacrylation of CSMA. The results of proliferation and fluorescence staining of rabbit articular chondrocytes in vitro culture demonstrated that the IPN hydrogels possessed good cytocompatibility. Furthermore, the IPN hydrogels could upregulate cartilage-specific gene expression and promote the chondrocytes secreting glycosaminoglycan and collagen II. These results suggested that IPN hydrogels might serve as promising hydrogel scaffolds for cartilage tissue engineering.


Assuntos
Cartilagem/fisiologia , Sulfatos de Condroitina/química , Colágeno/química , Ácido Hialurônico/química , Hidrogéis/síntese química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Animais , Animais Recém-Nascidos , Cartilagem/citologia , Bovinos , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Hidrogéis/química , Polímeros/síntese química , Polímeros/química , Coelhos
13.
J Phys Chem B ; 111(23): 6544-8, 2007 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-17506546

RESUMO

We focus our studies on DNA-chromophore motif on surfaces using samples prepared by the synthetic methods described by Wang and Li in a recent publication (J. Am. Chem. Soc. 2003, 125, 5248-5249). Scanning tunneling microscope (STM) was used to investigate the DNA-chromophore hybrids adsorbed on Au(111) and highly oriented pyrolytic graphite (HOPG) surfaces at room temperature in air. Experiments found that the DNA-chromophore hybrid molecules easily formed multimolecule aggregations on gold surface. On HOPG surfaces, however, DNA-chromophore hybrids were usually adsorbed as single molecules. STM images further showed DNA-chromophore hybrids adsorbed on Au(111) surfaces existed in the form of single molecule, dimer, trimer, tetramer, etc. The occurrence of molecular aggregations indicates that molecular interactions are comparable or stronger than molecule-substrate interactions; such weak interactions control the geometrical sizes and topographical shapes of the self-assembled DNA-chromophore hybrids on surfaces.


Assuntos
DNA/química , Ouro/química , Grafite/química , Microscopia de Tunelamento , Nanoestruturas/química , Eletroquímica , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície , Raios X
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