以16.7%(质量分数)的柠檬酸水溶液作溶剂,通过粒子沥滤法制备了 n HA/CS多孔材料,并对其进行了IR、XRD、SEM、孔隙率及力学性能测试。结果表明n HA/CS复合材料中羟基磷灰石呈弱结晶状态,复合前后两组分的化学组成未发生显著变化,但两相...以16.7%(质量分数)的柠檬酸水溶液作溶剂,通过粒子沥滤法制备了 n HA/CS多孔材料,并对其进行了IR、XRD、SEM、孔隙率及力学性能测试。结果表明n HA/CS复合材料中羟基磷灰石呈弱结晶状态,复合前后两组分的化学组成未发生显著变化,但两相间发生了相互作用。多孔材料呈高度多孔结构,孔壁上富含微孔,孔间贯通性高;复合材料/致孔剂质量比为1时,多孔材料的孔隙率为 53%,其抗压强度可达17 MPa左右,可以满足组织工程支架材料的要求。展开更多
将具有传骨性的生物可吸收无机材料硫酸钙与具有诱骨性的明胶组合起来,构制新型可吸收复合生物材料。该材料可避免硫酸钙颗粒的脱落,可以作为骨填充物或支架材料。明胶的加入减缓了半水硫酸钙向二水硫酸钙的转化,形成了CSH/CSD/CLG e l...将具有传骨性的生物可吸收无机材料硫酸钙与具有诱骨性的明胶组合起来,构制新型可吸收复合生物材料。该材料可避免硫酸钙颗粒的脱落,可以作为骨填充物或支架材料。明胶的加入减缓了半水硫酸钙向二水硫酸钙的转化,形成了CSH/CSD/CLG e l复合材料。在该复合材料表面培养了人成骨细胞,细胞在支架表面粘附良好,可见该支架和细胞有较好的生物相容性。硫酸钙吸收后形成一可供细胞生长的多孔支架,所以明胶/硫酸钙(CLG e l/CS)复合材料实为原位成孔支架材料,解决了多孔支架材料初期强度低的致命弱点。展开更多
The practical application of solid polymer electrolytes in high-energy Li metal batteries is hindered by Li dendrites,electrochemical instability and insufficient ion conductance.To address these issues,flexible compo...The practical application of solid polymer electrolytes in high-energy Li metal batteries is hindered by Li dendrites,electrochemical instability and insufficient ion conductance.To address these issues,flexible composite polymer electrolyte(CPE)membranes with three dimensional(3D)aramid nanofiber(ANF)frameworks are facilely fabricated by filling polyethylene oxide(PEO)-lithium bis(trifluoromethylsulphonyl)imide(Li TFSI)electrolyte into 3D ANF scaffolds.Because of the unique composite structure design and the continuous ion conduction at the 3D ANF framework/PEO-Li TFSI interfaces,the CPE membranes show higher mechanical strength(10.0 MPa),thermostability,electrochemical stability(4.6 V at 60℃)and ionic conductivity than the pristine PEO-Li TFSI electrolyte.Thus,the CPEs display greatly improved interfacial stability against Li dendrites(≥1000 h at 30℃under 0.10 m A cm-2),compared with the pristine electrolyte(short circuit in 13 h).The CPE-based all-solid-state LiFePO4/Li cells also exhibit superior cycling performance(e.g.,130 mA h g-1 with 93%retention after 100 cycles at 0.4 C)than the ANF-free cells(e.g.,82 mA h g-1 with 66%retention).This work offers a simple and effective way to achieve high-performance composite electrolyte membranes with 3D nanofiller framework for promising solid-state Li metal battery applications.展开更多
In the present study,novel biomimetic composite scaffolds with a composition similar to that of natural bone were prepared,using nano-hydroxyapatite,collagen,and phosphatidylserine.The scaffolds possess an interconnec...In the present study,novel biomimetic composite scaffolds with a composition similar to that of natural bone were prepared,using nano-hydroxyapatite,collagen,and phosphatidylserine.The scaffolds possess an interconnected porous structure with a porosity of 84%.The pore size ranges from several micrometers up to about 400 m.In-vitro studies in simulated body fluids showed that the morphologies of the products derived from mineralization can be regulated by the extracellular matrix components of the scaffolds;this in turn leads to creation of a large number of hydroxyapatite crystals on the scaffold surface.The regulatory properties of collagen and phosphatidylserine also influenced the cell response to the composite scaffolds.MC3T3-E1 cells attached and spread on the surfaces of the materials and interacted with the substrates;this may be the result of charged groups on the composite materials.Radiological analysis suggested that calluses and bone bridges formed in defects within 12 weeks.These composite scaffolds may therefore be a suitable replacement in bone-tissue engineering.展开更多
背景:对于支架物理性质的研究始终是组织工程研究领域的热点,但对于促血管支架来说,除了要满足支架的基本性能外,还需要通过其他方法来促进血管在支架内的再生过程,以达到修复骨组织的最终目的。目的:对国内外发表的骨组织工程下促血管...背景:对于支架物理性质的研究始终是组织工程研究领域的热点,但对于促血管支架来说,除了要满足支架的基本性能外,还需要通过其他方法来促进血管在支架内的再生过程,以达到修复骨组织的最终目的。目的:对国内外发表的骨组织工程下促血管支架的文献进行可视化分析,探究该领域的研究热点及研究现状,为后续研究提供参考。方法:以中国知网及Web of Science核心集数据库为检索库,检索骨组织工程下促血管支架的相关文献,去除不符合纳入标准的文献,随后导入CiteSpace 6.1.R2软件,对研究领域的作者、国家机构及关键词进行可视化分析。结果与结论:①骨组织工程下促血管支架应用的研究中,发文量最多的前3个国家分别为中国、美国和德国。②中国知网数据库机构该领域研究发文量排名前3位分别为南方医科大学、华中科技大学、东华大学;Web of Science核心集数据库中机构发文量排名前3位分别为上海交通大学、四川大学、中国科学院。③中国知网数据库关键词频次排名前3位为“组织工程、血管化、血管生成”,Web of Science核心集数据库关键词频次排名前3位为“mesenchymal stem cell(间充质干细胞),scaffold(支架),vascularization(血管化)”。④参考文献共被引情况和高被引文献分析显示,该领域的血管化策略研究热点为支架设计、血管生成因子的输送、体外共培养和体内预血管化;技术方面研究热点为3D打印、静电纺丝、血管移植及血管融合;机制方面研究热点为免疫调节和巨噬细胞、药物/生长因子输送、内皮细胞和成骨细胞之间的关系、骨细胞和内皮细胞之间旁分泌关系及信号分子通路、血管生成和抗血管生成分子。⑤国内外骨组织工程下促血管支架应用研究均十分重视干细胞和3D打印技术的运用,而目前的研究热点主要为生物3D打印技术、支架改性修饰的展开更多
Three dimensional（3D） bioprinting, which involves depositing bioinks（mixed biomaterials） layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However,...Three dimensional（3D） bioprinting, which involves depositing bioinks（mixed biomaterials） layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However, it remains challenging to prepare biomaterials with micro-nanostructures that accurately mimic the nanostructural features of natural tissues. A novel nanotechnological tool, electrospinning, permits the processing and modification of proper nanoscale biomaterials to enhance neural cell adhesion, migration, proliferation, differentiation, and subsequent nerve regeneration. The composite scaffold was prepared by combining 3D bioprinting with subsequent electrochemical deposition of polypyrrole and electrospinning of silk fibroin to form a composite polypyrrole/silk fibroin scaffold. Fourier transform infrared spectroscopy was used to analyze scaffold composition. The surface morphology of the scaffold was observed by light microscopy and scanning electron microscopy. A digital multimeter was used to measure the resistivity of prepared scaffolds. Light microscopy was applied to observe the surface morphology of scaffolds immersed in water or Dulbecco＇s Modified Eagle＇s Medium at 37℃ for 30 days to assess stability. Results showed characteristic peaks of polypyrrole and silk fibroin in the synthesized conductive polypyrrole/silk fibroin scaffold, as well as the structure of the electrospun nanofiber layer on the surface. The electrical conductivity was 1 × 10^-5–1 × 10^-3 S/cm, while stability was 66.67%. A 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2-H-tetrazolium bromide assay was employed to measure scaffold cytotoxicity in vitro. Fluorescence microscopy was used to observe Ed U-labeled Schwann cells to quantify cell proliferation. Immunohistochemistry was utilized to detect S100β immunoreactivity, while scanning electron microscopy was applied to observe the morphology of adherent Schwann cells. Results demonstrated that the polypyrrole/silk fibroin scaffold was not cytotoxic and 展开更多
The aim of this study is to investigate the applicability of poly(lactic-co-glycolic acid)(PLGA)/collagen composite scaffold for skin tissue engineering.PLGA and collagen were dissolved in HFIP as a common solvent and...The aim of this study is to investigate the applicability of poly(lactic-co-glycolic acid)(PLGA)/collagen composite scaffold for skin tissue engineering.PLGA and collagen were dissolved in HFIP as a common solvent and fibrous scaffolds were prepared by electrospinning method.The scaffolds were characterized by scanning electron microscopy(SEM),FTIR spectroscopy,mercury porosimetry,tensile strength,biocompatibility assays and Biodegradation.Cytotoxicity and cell adhesion were tested for two cell line groups,human dermal fibroblast(HDF)and human keratinocyte(HaCat).SEM images showed appropriate cell adhesion to the scaffold for both cell lines.MTT assays indicated that the cell viability of HDF cells increased with time,but the number of HaCat cells decreased after 14 days.The ultimate tensile strength was suitable for skin substitute application,but its elongation at break was rather low.For successful clinical application of the PLGA/collagen scaffold,some properties especially mechanical strain needs to be improved.展开更多
The development of lit;triton ion batteries （LIBs） relies on the improvement in the performance of electrode materials with higher capacity, higher rate capability, and longer cycle lift;. In this review article, th...The development of lit;triton ion batteries （LIBs） relies on the improvement in the performance of electrode materials with higher capacity, higher rate capability, and longer cycle lift;. In this review article, the recent advances in carbon nanotube （CNT） anodes, CNT-based composite electrodes, and CNT current collectors for high performance LIBs are concerned. CNT has received considerable attentions as a candidate material for the LIB applications. In addition to a possible choice for anode, CNT has been recognized as a solution in improving the performance of the state-of-the-art electrode materials. The CNT-based composite electrodes can be fabricated by mechanical or chem- ical approaches. Owing to the large aspect ratio and the high electrical conductivity, CNTs at very low loading can lead to an efficient conductive network. The excellent mechanical strength suggests the great potential in forming a structure scaffold to accommodate nano-sized electrode materials. Accordingly, the incorporation of CNTs will enhance the conductivity of the composite electrodes, mitigatc the agglomeration problem, decrease the dependence on inactive binders, and improve the clcctrochenfical properties of both anode and cathode materials remarkably. Freestanding CNT network can be used as lightweight current collectors to increase the overall energy density of LIBs. Finally, research perspectives for exploiting CNTs in high-performance LIBs are discussed.展开更多
文摘将具有传骨性的生物可吸收无机材料硫酸钙与具有诱骨性的明胶组合起来,构制新型可吸收复合生物材料。该材料可避免硫酸钙颗粒的脱落,可以作为骨填充物或支架材料。明胶的加入减缓了半水硫酸钙向二水硫酸钙的转化,形成了CSH/CSD/CLG e l复合材料。在该复合材料表面培养了人成骨细胞,细胞在支架表面粘附良好,可见该支架和细胞有较好的生物相容性。硫酸钙吸收后形成一可供细胞生长的多孔支架,所以明胶/硫酸钙(CLG e l/CS)复合材料实为原位成孔支架材料,解决了多孔支架材料初期强度低的致命弱点。
基金supported partially by Beijing Natural Science Foundation(L172036)Joint Funds of the Equipment Pre-Research and Ministry of Education(6141A020225)+2 种基金Par-Eu Scholars Program,Science and Technology Beijing 100 Leading Talent Training Project,Beijing Municipal Science and Technology Project(Z161100002616039)China Postdoctoral Science Foundation(2018M631419)the Fundamental Research Funds for the Central Universities(2017ZZD02 and 2019QN001).
文摘The practical application of solid polymer electrolytes in high-energy Li metal batteries is hindered by Li dendrites,electrochemical instability and insufficient ion conductance.To address these issues,flexible composite polymer electrolyte(CPE)membranes with three dimensional(3D)aramid nanofiber(ANF)frameworks are facilely fabricated by filling polyethylene oxide(PEO)-lithium bis(trifluoromethylsulphonyl)imide(Li TFSI)electrolyte into 3D ANF scaffolds.Because of the unique composite structure design and the continuous ion conduction at the 3D ANF framework/PEO-Li TFSI interfaces,the CPE membranes show higher mechanical strength(10.0 MPa),thermostability,electrochemical stability(4.6 V at 60℃)and ionic conductivity than the pristine PEO-Li TFSI electrolyte.Thus,the CPEs display greatly improved interfacial stability against Li dendrites(≥1000 h at 30℃under 0.10 m A cm-2),compared with the pristine electrolyte(short circuit in 13 h).The CPE-based all-solid-state LiFePO4/Li cells also exhibit superior cycling performance(e.g.,130 mA h g-1 with 93%retention after 100 cycles at 0.4 C)than the ANF-free cells(e.g.,82 mA h g-1 with 66%retention).This work offers a simple and effective way to achieve high-performance composite electrolyte membranes with 3D nanofiller framework for promising solid-state Li metal battery applications.
基金supported by Science and Technology Plan Project of Fu-jian Department of Education,China(JK2009021)
文摘In the present study,novel biomimetic composite scaffolds with a composition similar to that of natural bone were prepared,using nano-hydroxyapatite,collagen,and phosphatidylserine.The scaffolds possess an interconnected porous structure with a porosity of 84%.The pore size ranges from several micrometers up to about 400 m.In-vitro studies in simulated body fluids showed that the morphologies of the products derived from mineralization can be regulated by the extracellular matrix components of the scaffolds;this in turn leads to creation of a large number of hydroxyapatite crystals on the scaffold surface.The regulatory properties of collagen and phosphatidylserine also influenced the cell response to the composite scaffolds.MC3T3-E1 cells attached and spread on the surfaces of the materials and interacted with the substrates;this may be the result of charged groups on the composite materials.Radiological analysis suggested that calluses and bone bridges formed in defects within 12 weeks.These composite scaffolds may therefore be a suitable replacement in bone-tissue engineering.
文摘背景:对于支架物理性质的研究始终是组织工程研究领域的热点,但对于促血管支架来说,除了要满足支架的基本性能外,还需要通过其他方法来促进血管在支架内的再生过程,以达到修复骨组织的最终目的。目的:对国内外发表的骨组织工程下促血管支架的文献进行可视化分析,探究该领域的研究热点及研究现状,为后续研究提供参考。方法:以中国知网及Web of Science核心集数据库为检索库,检索骨组织工程下促血管支架的相关文献,去除不符合纳入标准的文献,随后导入CiteSpace 6.1.R2软件,对研究领域的作者、国家机构及关键词进行可视化分析。结果与结论:①骨组织工程下促血管支架应用的研究中,发文量最多的前3个国家分别为中国、美国和德国。②中国知网数据库机构该领域研究发文量排名前3位分别为南方医科大学、华中科技大学、东华大学;Web of Science核心集数据库中机构发文量排名前3位分别为上海交通大学、四川大学、中国科学院。③中国知网数据库关键词频次排名前3位为“组织工程、血管化、血管生成”,Web of Science核心集数据库关键词频次排名前3位为“mesenchymal stem cell(间充质干细胞),scaffold(支架),vascularization(血管化)”。④参考文献共被引情况和高被引文献分析显示,该领域的血管化策略研究热点为支架设计、血管生成因子的输送、体外共培养和体内预血管化;技术方面研究热点为3D打印、静电纺丝、血管移植及血管融合;机制方面研究热点为免疫调节和巨噬细胞、药物/生长因子输送、内皮细胞和成骨细胞之间的关系、骨细胞和内皮细胞之间旁分泌关系及信号分子通路、血管生成和抗血管生成分子。⑤国内外骨组织工程下促血管支架应用研究均十分重视干细胞和3D打印技术的运用,而目前的研究热点主要为生物3D打印技术、支架改性修饰的
基金supported by the National Natural Science Foundation of China,No.81671823,81701835a grant from the National Key Research and Development Program of China,No.2016YFC1101603a grant from the Natural Science Research Program of Nantong of China,No.MS12016056
文摘Three dimensional（3D） bioprinting, which involves depositing bioinks（mixed biomaterials） layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However, it remains challenging to prepare biomaterials with micro-nanostructures that accurately mimic the nanostructural features of natural tissues. A novel nanotechnological tool, electrospinning, permits the processing and modification of proper nanoscale biomaterials to enhance neural cell adhesion, migration, proliferation, differentiation, and subsequent nerve regeneration. The composite scaffold was prepared by combining 3D bioprinting with subsequent electrochemical deposition of polypyrrole and electrospinning of silk fibroin to form a composite polypyrrole/silk fibroin scaffold. Fourier transform infrared spectroscopy was used to analyze scaffold composition. The surface morphology of the scaffold was observed by light microscopy and scanning electron microscopy. A digital multimeter was used to measure the resistivity of prepared scaffolds. Light microscopy was applied to observe the surface morphology of scaffolds immersed in water or Dulbecco＇s Modified Eagle＇s Medium at 37℃ for 30 days to assess stability. Results showed characteristic peaks of polypyrrole and silk fibroin in the synthesized conductive polypyrrole/silk fibroin scaffold, as well as the structure of the electrospun nanofiber layer on the surface. The electrical conductivity was 1 × 10^-5–1 × 10^-3 S/cm, while stability was 66.67%. A 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2-H-tetrazolium bromide assay was employed to measure scaffold cytotoxicity in vitro. Fluorescence microscopy was used to observe Ed U-labeled Schwann cells to quantify cell proliferation. Immunohistochemistry was utilized to detect S100β immunoreactivity, while scanning electron microscopy was applied to observe the morphology of adherent Schwann cells. Results demonstrated that the polypyrrole/silk fibroin scaffold was not cytotoxic and
基金The authors wish to acknowledge the financial support of the Iranian Academic Center for Education,Culture and Research(ACECR)(Grant No.2146-21).
文摘The aim of this study is to investigate the applicability of poly(lactic-co-glycolic acid)(PLGA)/collagen composite scaffold for skin tissue engineering.PLGA and collagen were dissolved in HFIP as a common solvent and fibrous scaffolds were prepared by electrospinning method.The scaffolds were characterized by scanning electron microscopy(SEM),FTIR spectroscopy,mercury porosimetry,tensile strength,biocompatibility assays and Biodegradation.Cytotoxicity and cell adhesion were tested for two cell line groups,human dermal fibroblast(HDF)and human keratinocyte(HaCat).SEM images showed appropriate cell adhesion to the scaffold for both cell lines.MTT assays indicated that the cell viability of HDF cells increased with time,but the number of HaCat cells decreased after 14 days.The ultimate tensile strength was suitable for skin substitute application,but its elongation at break was rather low.For successful clinical application of the PLGA/collagen scaffold,some properties especially mechanical strain needs to be improved.
基金Acknowledgements This work was supported by the National Basic Research Program of China （Grant No. 2012CB932301）, the National Natural Science Foundation of China （Grant Nos. 51102146 and 50825201）, and the Chhmse Postdoctoral Science Foundation （2012NI520261）.
文摘The development of lit;triton ion batteries （LIBs） relies on the improvement in the performance of electrode materials with higher capacity, higher rate capability, and longer cycle lift;. In this review article, the recent advances in carbon nanotube （CNT） anodes, CNT-based composite electrodes, and CNT current collectors for high performance LIBs are concerned. CNT has received considerable attentions as a candidate material for the LIB applications. In addition to a possible choice for anode, CNT has been recognized as a solution in improving the performance of the state-of-the-art electrode materials. The CNT-based composite electrodes can be fabricated by mechanical or chem- ical approaches. Owing to the large aspect ratio and the high electrical conductivity, CNTs at very low loading can lead to an efficient conductive network. The excellent mechanical strength suggests the great potential in forming a structure scaffold to accommodate nano-sized electrode materials. Accordingly, the incorporation of CNTs will enhance the conductivity of the composite electrodes, mitigatc the agglomeration problem, decrease the dependence on inactive binders, and improve the clcctrochenfical properties of both anode and cathode materials remarkably. Freestanding CNT network can be used as lightweight current collectors to increase the overall energy density of LIBs. Finally, research perspectives for exploiting CNTs in high-performance LIBs are discussed.
