To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared ...To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, i.e. solventcasting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behaviorof the porous scaffold, e.g. weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP,the particle size of β-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporatedinto the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold weredetermined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Resultsshow that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strengthneeded for surgery. RMSCs seeding on porous PLLA/β-TCP composite behaves good seeding efficacy, biocompatibility andosteoinductive potential. Osteoprogenitor cells could well penetrate into the material matrix and begin cell proliferation andosteogenic differentiation. Osseous matrix could be formed on the surface of the composite after culturing in vitro. It isexpected that the PLLA/β-TCP porous composites are promising scaffolds for bone tissue engineering in prosthesis surgery.展开更多
Highly porous ultrafine electrospun scaffolds,gelatin/poly(L-lactic acid)(PLLA) and chitosan/PLLA were prepared by blending gelatin and PLLA,chitosan and PLLA respectively.The biocompatibilities of these scaffolds wer...Highly porous ultrafine electrospun scaffolds,gelatin/poly(L-lactic acid)(PLLA) and chitosan/PLLA were prepared by blending gelatin and PLLA,chitosan and PLLA respectively.The biocompatibilities of these scaffolds were assessed by attachment,proliferation and viability of cells on them.The results indicated that over 30%WI-38 cells could attach to the gelatin/PLLA and chitosan/PLLA scaffolds at 2 h after seeding,while the attachment of the cells was only 15%on PLLA scaffolds.Both gelatin/PLLA and chitosan/PLLA scaffolds also exhibited a very good ability for proliferation of WI-38 cells.Cell growth on the gelatin/PLLA and chitosan /PLLA scaffolds showed dramatic improvement,indicating a much better biocompatibility in the blends contributed by gelatin and chitosan.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay also demonstrated gelatin/PLLA showed better ability to enhance the growth and functions of the cells.These assays suggest that the electrospun gelatin/PLLA and chitosan/PLLA scaffolds are promising biomaterials with great biocompatibility for the development of skin tissue engineering.展开更多
目的制备聚乳酸（PLLA）三维微小凹图式并实现图式上新生大鼠海马神经干细胞（NSC）三维聚集体的形成及培养。方法用2只新生1~3 d SPF级SD大鼠体外分离提取海马组织并培养NSC,观察其悬浮神经球和贴壁生长特性;以紫外光光刻和复制模塑法...目的制备聚乳酸（PLLA）三维微小凹图式并实现图式上新生大鼠海马神经干细胞（NSC）三维聚集体的形成及培养。方法用2只新生1~3 d SPF级SD大鼠体外分离提取海马组织并培养NSC,观察其悬浮神经球和贴壁生长特性;以紫外光光刻和复制模塑法制备3种不同结构尺寸的PLLA微小凹图式;以普通光学显微镜和Image J图像处理软件研究图式上NSC聚集体的形成及大小分布;以免疫细胞荧光技术研究图式上NSC标志物Nestin的表达。结果 NSC在体外能够以悬浮神经球和贴壁生长的2种方式生长。在所研究的3种结构尺寸的图式中,无通道（120-0μm）和通道宽度为20μm（120-20μm）的微小凹图式更利于NSC聚集体的形成（P〈0.01）;而在通道宽度为40μm的图式（120-40μm）上NSC更倾向于沿通道方向生长、迁移,并形成准一维排布的三维神经细胞网络。图式上聚集体Feret’s直径分布均匀,无大的聚集体（直径〉120μm）出现。在细胞聚集体及神经细胞网络形成期间NSC均保持Nestin阳性表达。结论 PLLA微小凹图式可用于体外NSC聚集体形成及神经细胞网络的三维图式化,这为干细胞组织工程及基于神经细胞的微系统提供了有效的研究及应用途径。展开更多
基金This study was financially supported by 863 Hj-Tech ResearchDevelopment Program of China(2002AA326080)The Fund for Youth Teacher of Education Mlinistry of China(2002123).
文摘To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, i.e. solventcasting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behaviorof the porous scaffold, e.g. weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP,the particle size of β-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporatedinto the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold weredetermined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Resultsshow that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strengthneeded for surgery. RMSCs seeding on porous PLLA/β-TCP composite behaves good seeding efficacy, biocompatibility andosteoinductive potential. Osteoprogenitor cells could well penetrate into the material matrix and begin cell proliferation andosteogenic differentiation. Osseous matrix could be formed on the surface of the composite after culturing in vitro. It isexpected that the PLLA/β-TCP porous composites are promising scaffolds for bone tissue engineering in prosthesis surgery.
基金the Project of the Science and Technology Commission of Shanghai Municipality (No.Ilnm0505100)the China Postdoctoral Science Foundation(No.2012M510116)the Fundamental Research Funds for the Central Universities (No.0500219160)
文摘Highly porous ultrafine electrospun scaffolds,gelatin/poly(L-lactic acid)(PLLA) and chitosan/PLLA were prepared by blending gelatin and PLLA,chitosan and PLLA respectively.The biocompatibilities of these scaffolds were assessed by attachment,proliferation and viability of cells on them.The results indicated that over 30%WI-38 cells could attach to the gelatin/PLLA and chitosan/PLLA scaffolds at 2 h after seeding,while the attachment of the cells was only 15%on PLLA scaffolds.Both gelatin/PLLA and chitosan/PLLA scaffolds also exhibited a very good ability for proliferation of WI-38 cells.Cell growth on the gelatin/PLLA and chitosan /PLLA scaffolds showed dramatic improvement,indicating a much better biocompatibility in the blends contributed by gelatin and chitosan.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay also demonstrated gelatin/PLLA showed better ability to enhance the growth and functions of the cells.These assays suggest that the electrospun gelatin/PLLA and chitosan/PLLA scaffolds are promising biomaterials with great biocompatibility for the development of skin tissue engineering.
