共查询到18条相似文献,搜索用时 277 毫秒
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研究一种具有径向和轴向孔径梯度的变形Gyroid单元多孔结构参数化设计方法,采用激光选区熔化成形(selective laser melting, SLM)技术,制备出孔隙率为60%和75%的钛合金变形Gyroid单元梯度多孔结构样件。使用有限元法(finiteelementmethod,FEM)对4组梯度多孔支架模型及2组均质模型进行静力学仿真分析,对制备的钛合金梯度多孔样件进行力学性能测试,并与已测试过的均质样件进行力学性能对比分析。有限元计算结果与力学性能试验结果共同表明:变形Gyroid单元多孔结构力学性能随孔隙率的升高而降低,孔隙率相同时,径向梯度多孔支架力学性能优于均质多孔支架,更适用于皮质骨的骨缺损修复,轴向梯度多孔支架力学性能相比均质多孔支架有所减弱,更适用于松质骨。 相似文献
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采用叔丁醇溶液为冷冻媒介,冷冻干燥技术制备出网眼状多孔氧化铝陶瓷支架。通过改变冷冻温度影响网眼孔陶瓷支架孔径,并对不同孔径的网眼孔支架进行生物性能分析。结果表明,采用叔丁醇冷冻干燥技术制备的网眼孔支架主要以开孔为主,网眼孔支架孔径随着冷冻温度的降低而减少,但支架的开孔孔隙率不受冷冻温度影响。体外模拟实验表明,大孔径的网眼孔支架有利于细胞在表面生长,细胞贴壁生长,形态正常。支架表面细胞的附着率随支架孔径的增大而增多。 相似文献
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针对目前骨组织工程支架微孔结构难以准确设计制备的问题,提出了一种基于点云的参数化建模+3D打印新方法。通过提取cube(C)、diamond(D)、gyroid(G)3种结构的型面函数点云数据,完成对不同孔结构特征的参数化建模。通过对模型有限元力学分析,对不同孔结构特征的多孔钛骨组织支架进行力学设计与订制。借助激光选区熔融(SLM)3D打印技术,完成对不同孔特征的骨组织支架快速成型。对多孔钛骨组织支架进行了相关材料学表征,包括孔结构表征与力学性能测试。结果表明:参数化模型的快速成型制造,能够有效地设计制备钛合金骨组织工程支架的孔结构特性,且可有效设计订制支架的力学性能,从仿生的角度实现多孔钛合金骨组织工程支架生物学功能的设计优化。 相似文献
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金属3D打印技术成为当前最具有发展潜力和发展前景的工业制造技术之一,通过SLM激光选区烧结技术,选取合理的烧结参数,将金属粉末烧结成型。建立了不同孔径的多孔支架复杂三维模型,并通过有限元分析进行应力、应变的模拟分析,获得了优化后的多孔支架三维模型,为后续的实验研究分析建立理论基础,然后通过SLM烧结技术制备316L不锈钢多孔支架,通过后期热处理实验、压缩试验、金相实验,对多孔试样进行力学性能分析、硬度测试以及表面微观组织分析。通过模拟分析获得优化后的多孔支架孔径尺寸,获得了更适于人体骨骼缺损部位承重的多孔支架,可对后续研究进行指导。实验研究发现300μm孔径支架强度和弹性模量都高于天然骨,而成形多孔结构的金属件保证了骨骼修复体的生物力学性能,具有良好的力学性能。 相似文献
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采用Ca(OH)2/H3PO4中和反应,超声分散条件下制备β-TCP粉末原料;通过致孔剂方法制备多孔β-TCP支架,并在β-TCP成型过程中加入K2HPO4提高支架强度将制备的多孔支架与明胶复合,冷冻干燥后与戊二醛交联,得到多孔β-TCP/明胶复合支架.实验表明,加入K2HPO4后提高了支架强度,当多孔β-TCP支架孔隙率为49.47%时抗压强度为7.60 MPa.多孔β-TCP支架的孔隙率高、强度高、孔隙大小可控、孔隙连通性好;进一步与明胶复合后,制各的多孔β-TCP/明胶复合材料,符合组织工程结构特征的要求. 相似文献
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无机-有机复合组织器官工程支架的微纳制造是近年来兴起的生物材料研究领域,相对传统的生物材料与组织工程材料制造技术,微纳制造整合了微纳米技术、计算机辅助设计、数字化制造等先进技术手段,为新型生物医用材料的开发以及生物材料制造新技术、新设备的研发提供了新的技术路线。综述了生物医用材料、特别是组织器官工程与组织修复材料微纳制造技术现状及发展趋势,主要内容包括生物材料的微纳米化及实现途径、组织器官工程支架材料的数字化设计、组织器官工程支架材料的数字化制造新技术等,对我国组织器官工程(修复)材料数字化微纳制造新技术的优先发展领域提出了展望。 相似文献
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本文从凝固理论、凝固方法与装置、凝固体系、性能及应用等方面,综述了定向凝固多孔金属的研究进展。圆柱形气孔规则排列的多孔金属是通过定向凝固方法在加压气氛中利用金属/气体共晶反应制备的。通过控制凝固方向,不仅可以制备一维藕状多孔结构,还可以制备二维放射状多孔结构。参考经典的JacksonHunt共晶模型,建立了稳态凝固条件下金属-气体共晶定向凝固的理论模型,并且给出了考虑H2逸出和定向凝固多孔结构形成的工艺参数窗口。介绍了模铸法、连续铸造法和Bridgman型定向凝固法3种制备技术。重点介绍了定向凝固多孔结构制备过程中的2个重要进展:孔结构均匀的定向凝固多孔合金的制备以及高孔隙率定向凝固多孔Al的制备。圆柱形气孔规则排列使得定向凝固多孔金属在力、热、声以及渗透等方面具有特殊的性能优势,因此在轻质结构材料、热沉、过滤器和人工骨等领域具有广阔的应用前景。 相似文献
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3D打印技术制备医用生物多孔支架是目前最有前景和吸引力的生物医学应用之一.采用建模软件(C4D)通过随机域建立自生长多孔结构支架,最大程度地模拟松质骨的形态和结构.通过选择性激光熔化技术获得默认尺寸120%、160%、200%和240%比例的的三维结构模型.通过金相分析、热处理、硬度测试和压缩实验,对自生长多孔支架试样... 相似文献
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W. W. Thein-Han R. D. K. Misra 《JOM Journal of the Minerals, Metals and Materials Society》2009,61(9):41-44
We describe the structure of biodegradable chitosan-nanohydroxyapatite (nHA) composites scaffolds and their interaction with
pre-osteoblasts for bone tissue engineering. The scaffolds were fabricated via freezing and lyophilization. The nanocomposite
scaffolds were characterized by a highly porous structure and pore size of ∼50–125 μm, irrespective of nHA content. The observed
significant enhancement in the biological response of pre-osteoblast on nanocomposite scaffolds expressed in terms of cell
attachment, proliferation, and widespread morphology in relation to pure chitosan points toward their potential use as scaffold
material for bone regeneration. 相似文献
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人口老龄化,疾病以及交通事故等造成大量的人体骨组织损伤和丢失。如何实现骨组织缺损的快速修复与再生成为临床医学研究的重要课题和目标,而生物医用材料在其中发挥着极其重要的作用。目前临床上常用的骨组织修复材料如自体骨、异体骨、合成材料(金属,陶瓷,高分子)等都存在各种各样的问题,无法实现大规模的应用和骨组织的快速有效再生。而骨组织工程学科研究多孔支架结合细胞和生长因子来实现骨组织再生,以鳃决骨科临床面临的问题为目的。最近十多年来,三维纳米纤维支架由于可以仿天然细胞外基质的结构和形态而显示出较强的促进细胞增殖、成骨分化以及骨组织修复再生的能力。主要综述具有仿生的纳米纤维及其复合支架材料的制备技术以及他们在增强细胞功能、干细胞成骨分化、及其骨组织再生中的应用。 相似文献
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A challenge for tissue engineering is to produce synthetic scaffolds of adequate chemical, physical and biological cues effectively. This paper describes a plasma-assisted bio-extrusion system to produce functional-gradient scaffolds; it comprises pressure-assisted and screw-assisted extruders, and plasma jets. This paper also describes how the system conducts plasma surface modification during the polycaprolactone scaffold fabrication process. Water contact angle and in vitro biological tests confirm that the plasma modification alters the hydrophilicity properties of synthetic polymers and promotes proliferation of cells, leading to homogeneous cell colonization. The results suggest this system is promising for producing functional gradient scaffolds of biomaterials. 相似文献
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Andrew J. Steward Yongxing Liu Diane R. Wagner 《JOM Journal of the Minerals, Metals and Materials Society》2011,63(4):74-82
One of the challenges of tissue engineering, a promising cell-based treatment for damaged or diseased cartilage, is designing
the scaffold that provides structure while the tissue regenerates. In addition to the scaffold material’s biocompatibility,
mechanical properties, and ease of manufacturing, scaffold interactions with the cells must also be considered. In cartilage
tissue engineering, a range of scaffolds with various degrees of cell attachment have been proposed, but the attachment density
and type have yet to be optimized. Several techniques have been developed to modulate cell adhesion to the scaffold. These
studies suggest that the need for cell attachment in cartilage tissue engineering may vary with cell type, stage of differentiation,
culture condition, and scaffold material. Further studies will elucidate the role of cell attachment in cartilage regeneration
and enhance efforts to engineer cell-based cartilage therapies. 相似文献
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钽金属是一种理想的医用金属材料,能够与人体软/硬组织发生整合。利用化学气相沉积方法,在可控多孔结构的Ti6Al4V合金支架表面沉积涂覆钽金属涂层,使其同时具备理想的三维孔隙结构和力学相容性,以及钽金属优异的生物学性能。研究结果显示,多孔钛合金支架表面涂层前后色泽发生明显变化,涂层后支架呈现钽金属色泽。扫描电镜和XRD分析进一步证明了多孔钛合金支架表面沉积物为钽金属。与美国Zimmer公司生产的多孔钽小梁金属相比,钽涂层多孔钛合金支架具备与人体皮质骨更相似的弹性模量和抗压强度,是一种理想的骨修复替代物。 相似文献
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Nicholas W. Meghri Amalie E. Donius Benjamin W. Riblett Elizabeth J. Martin Alisa Morss Clyne Ulrike G. K. Wegst 《JOM Journal of the Minerals, Metals and Materials Society》2010,62(7):71-75
Vascularization is a primary challenge in tissue engineering. To achieve it in a tissue scaffold, an environment with the
appropriate structural, mechanical, and biochemical cues must be provided enabling endothelial cells to direct blood vessel
growth. While biochemical stimuli such as growth factors can be added through the scaffold material, the culture medium, or
both, a well-designed tissue engineering scaffold is required to provide the necessary local structural and mechanical cues.
As chitosan is a well-known carrier for biochemical stimuli, the focus of this study was on structure-property correlations,
to evaluate the effects of composition and processing conditions on the three-dimensional architecture and properties of freeze-cast
scaffolds; to establish whether freeze-east scaffolds are promising candidates as constructs promoting vascularization; and
to conduct initial tissue culture studies with endothelial cells on flat substrates of identical compositions as those of
the scaffolds to test whether these are biocompatible and promote cell attachment and proliferation. 相似文献
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In this study, the macroporous forsterite scaffolds with highly interconnected spherical pores, with sizes ranged from 50 to 200 μm have been successfully fabricated via gelcasting method. The crystallite size of the forsterite scaffolds was measured in the range 26-35 nm. Total porosity of different bodies sintered at different sintering temperatures was calculated in the range 81-86%, while open porosity ranges from 69 to 78%. The maximum values of compressive strength and elastic modulus of the prepared scaffolds were found to be about 2.43 MPa and 182 MPa, respectively, which are close to the lower limit of the compressive strength and elastic modulus of cancellous bone and the compressive strength is equal to the standard for a porous bioceramic bone implant (2.4 MPa). Transmission electron microscopy analyses showed that the particle sizes are smaller than 100 nm. In vitro test in the simulated body fluid proved the good bioactivity of the prepared scaffold. It seems that, the mentioned properties could make the forsterite scaffold appropriate for tissue engineering applications, but cell culture and in vivo tests are needed for more confidence. 相似文献