人牙髓细胞三维生物打印的初步研究

通过生物打印方法构建含人牙髓细胞(human dental pulp cells,hDPCs)的组织工程三维结构体。探讨对hDPCs进行三维生物打印的可行性。用常规体外培养hDPCs至第4代。将细胞悬液与海藻酸钠-明胶水溶胶混合,制备hDPCs-海藻酸钠-明胶水溶胶共混物。细胞终密度为2×106/mL。用生物打印机根据预先设计的参数进行生物打印,构建组织工程三维结构体。对结构体进行肉眼观察和倒置相差显微镜观察。用钙黄绿素-AM和碘化丙啶双荧光染料对结构体进行染色,激光共聚焦显微镜观察分析结构体中hDPCs的活性。通过生物打印技术的结果可按照预先设计的参数打印出含有hDPCs的网格状的水凝胶结构体,该结构体的大小约为5 mm×5 mm×1.5 mm。倒置相差显微镜下可见结构体内微丝的直径约300μm,微丝间的孔隙相互通连,孔隙大小约350μm×350μm,hDPCs在结构体中呈球形均匀分布。激光共聚焦显微镜观察证实结构体中大部分细胞存活。初步证明hDPCs可耐受生物打印过程。通过研究说明三维生物打印技术构建出了含人牙髓细胞的组织工程三维结构体,实现了hDPCs的生物打印,为生物打印技术应用于牙组织工程奠定了基础。     

对3D打印医疗器械管理的政策建议

 3D打印技术,又称为增材制造技术,是一种通过三维数据,通常由逐层加工的方式结合材料以制造构件的技术。近年来,随着技术的发展,3D打印已率先在医疗领域获得应用上的突破。这主要因为医疗行业个性定制化需求显著,鲜有标准的量化生产,而个性化、小批量和高精度恰是3D打印技术的优势所在^[1]。目前,3D打印在医疗器械领域的应用主要包括：体外医疗器械,如医疗模型、假肢、齿科手术模板等;个性化植入物,如颅骨修复、颈椎人工椎体及人工关节等;常规植入物,如关节柄的表面修饰、种植牙、补片等;加入细胞3D打印人体器官等^[2]。     

面向组织工程的多细胞结构三维自组装成形方法的研究进展

多细胞结构是由细胞群体构成的有机体,其体外构建对于组织工程和再生医学的发展具有重要的基础意义。利用细胞自身的自组织特性构建三维(3D)多细胞结构正成为生物制造和组织再生的一种重要途径,并受到越来越多的关注。对三维多细胞结构的自组装式构建与调控的相关基础研究及关键技术进行了综述及分析,主要涉及凝胶内3D细胞培养、多细胞结构可控形成,及其与图灵反应-扩散机制的联系等方面的研究工作。为进一步研究多细胞3D自组装机理,使得该自组装过程可控,且满足同时调控外部施加和细胞自身分泌的作用因子的浓度梯度分布的需求,提出对内部结构特征梯度化的3D凝胶体内细胞3D自组装模型进行研究,以推进三维多细胞结构及组织前体形成的理性调控技术。     

广州迈普：生物3D打印领域的领头羊

将生物3D打印迈向普罗大众 2008年,广州迈普再生医学科技有限公司（Medprin Regenerative Medical Technologies Co.Ltd,以下简称迈普）正式成立。公司的创办人是师从于美国克莱姆森大学托马斯.波兰教授的徐弢与袁玉宇。托马斯.波兰教授为何许人？其正是现代意义生物3D打印技术概念的最早提出者。这一技术概念是指打印细胞活体等材料,并定位于构建三维组织和器官的新型生物3D打印,即细胞和器官打印。     

3D生物打印在组织工程应用中的技术难题和前景展望

目前,利用3D生物打印技术已能打印出生物的生理功能与结构简单、不具备完整血管和神经系统的体外组织/器官,要实现打印出具有可供移植、具备生物活性和完整生理功能的器官,还需要攻克打印技术和策略、血管和微观通道构建、仿生结构、打印墨水等方面的技术难题。对3D生物打印技术的发展前景及其在组织工程中的应用进行了展望。     

3D打印技术在陶瓷制造中的应用

3D打印技术作为区别于传统制造技术的一种新型技术,近年来在陶瓷制造领域得到了广泛的应用.该技术无需模具,可快速制备出形状复杂的陶瓷部件.系统综述了6种常见的3D打印技术包括浆料堆积成型技术、光固化成型技术、激光选区烧结技术、分层实体成型技术、三维打印成型技术、喷射打印成型技术在陶瓷制造领域的研究进展.综合3D打印技术在陶瓷制造领域的应用现状,展望了未来陶瓷3D打印技术的发展趋势.     

个性化聚醚醚酮植入物的制造工艺研究

为了解决个性化假体数控加工材料浪费严重、加工成本高、异形薄壁件加工困难,以及增材制造力学性能不足的难题,提出了一种利用光固化3D打印技术制造个性化聚醚醚酮(poly-ether-ether-ketone,PEEK)假体的耐高温树脂注塑模具,并进一步通过注塑工艺获得高强度个性化假体的方案。该方案充分地结合了3D打印技术和传统注塑技术的优势,即利用3D打印技术实现复杂的结构形状,利用传统注塑技术实现优异的综合力学性能。研究了在模芯设计过程中分型面的设计原则、模芯合模固定方式的选择原则以及模芯是否填充材料的原则。利用该方案制造了个性化PEEK颅骨和下颌骨假体,并对注塑件进行结晶度测试、组织观察。结果显示,PEEK注塑件的结晶度为30.82%,注塑件组织致密,无孔隙和缺损。因此,采用3D打印和注塑相结合的方案制造具有综合力学性能的个性化PEEK植入物是可行的,对个性化PEEK植入物在临床的广泛应用具有一定的参考作用。     

基于3D打印的仿生材料

随着3D打印技术的飞速发展和广泛应用,能够模仿和制造的生物仿生结构越来越多样化.简单介绍了现有的3D打印技术,并从结构、功能、医用和智能材料等方面综述了3D打印技术结合仿生领域的研究成果,如贝壳珍珠层、龙虾螯棒、鲨鱼皮、荷叶、血管网络和义肢等;最后讨论了3D打印技术在仿生领域面临的挑战和发展前景.     

2020年3D打印热点回眸

 3D打印是基于材料累加原理,将计算机中的三维模型通过分层添加材料打印出实物的一种增材制造技术。2020年,3D打印研究在打印机理、技术改进及应用拓展等方面取得了重要进展。从打印方法改进、新型墨水研发、新型结构制备和应用,以及金属3D打印机理研究等方面回顾了3D打印的年度研究热点和代表性成果。     

短肽自组装技术构建纳米三维细胞培养基质

绝大多数用于细胞3D(3-dimension,3D)培养的生物材料支架具有多孔渗水性的无定形结构,能被生物降解,但没有生物活性,也没有组织特异性,其支架显微结构与体内ECM(extracellular matrix,ECM)相差很大.目前,国际上兴起用短肽自组装技术构建纳米三维细胞培养基质,它具有纳米级结构、具有生物活性、组织特异性、成分清楚可控、生物力学、显微结构与体内一致等特征.纳米三维细胞培养基质在细胞生物学,肿瘤学,高通量药物筛选,组织工程,再生医学,以及生物纳米材料的发展具有重要的意义.     

Direct ink writing of polycaprolactone/polyethylene oxide based 3D constructs

There has been increasing interest over recent years in the application of three-dimensional(3 D) printing technologies in the biomedical field. One such method is Direct Ink Writing(DIW); this approach has the potential advantage of allowing room-temperature deposition of materials, presented as an ink, to build complex architectures. DIW offers the ability to process biomaterials containing temperature-sensitive components. Due to the fabrication principles of DIW, there are specific rheological requirements that the ink must exhibit for the 3 D construction. For this reason, hydrogel-based liquid feed stocks have been the focal point of ink development. As a consequence, studies based on inks comprising hydrophobic biomaterials, which are insoluble in water and hence unsuited to the hydrogel approach, have been limited.In this study, we investigate novel inks that utilize polycaprolactone(PCL), a hydrophobic polymer, as the primary constituent by dissolving the polymer in solvent systems based on dichloromethane(DCM) and acetone(ACE). Moreover, polyethylene oxide(PEO) was incorporated into the PCL systems in order to extend the range of hydrophilicity of the systems. The rheological properties of the inks were investigated as a function of polymer composition and solvent system. Woodpile constructs of PCL and PCL/PEO were fabricated using DIW method and were assessed by a series of material characterisation. The type of solvent system had a noticeable impact on the ink rheology, which ultimately affected the surface properties. The incorporation of PEO particularly enhanced the roughness and wettability of the constructs. Our results support the use of DIW as a new means to process hydrophobic polymers for biomedical applications.     

Strontium Substituted Nanohydroxyapatite Incorporated 3D Printing Scaffold for Bone Tissue Engineering

The customized implants which are composed of polycaprolactone( PCL) and strontium substituted nanohydroxyapatite( SrHA) were fabricated successfully by using fused deposition modeling( FDM),which is a simple 3 D printing technology for fabricating personalized products. The physical and chemical properties of composite scaffolds were characterized by transmission electron microscopy( TEM), Fourier transform infrared spectroscopy( FTIR), X-Ray diffraction( XRD) and inductively coupled plasma-atomic emission spectroscopy( ICPAES). The results suggested that strontium element was successfully doped into nanohydroxyapatite and all scaffolds showed the homogeneous network structure. Furthermore, the in vitro biocompatibility of the scaffolds was evaluated by cell counting kit-8( CCK-8) assay. The data indicated that the prepared scaffolds exhibited excellent biocompatibility to bone marrow mesenchymal stem cells( BMSCs). Besides,strontium element can be released from PCL-SrHA scaffolds in a sustained manner. Therefore,the 3 D printing PCL-SrHA scaffolds hold great potential for bone tissue engineering.     

宋代古船的三维激光扫描技术重建与模型3D打印

针对古文物的完整有效保存,文物研究、修复,以及其可能造成的毁损,提出采用三维激光扫描技术对文物进行数字化重建.构建文物真实三维模型,并通过3D打印技术制作文物的高精度实体复原模型.以宋代古船实体模型重建为例,对所提出的方法进行验证,研究结果表明:三维激光扫描技术和3D 打印技术可以提高文物历史信息的保存和修复效率,避免接触式测量文物造成的表面损坏,提高研究人员对文物分析研究的参与度.但是,对于表面纹理比较复杂的文物,这项技术依然存在精度上的缺陷.     

Emergent Technologies for Cardiovascular Surgery

The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of fidelity between the device and the patient.As regenerative medicine is still in its infancy,the ongoing search for new and effective prosthetic alternatives continues to be essential and highly rewarding.Thanks in part to the progress of imaging and the benefits of 3D printing,previously unimagined emergent technologies are at hand.The emerging technologies of the last few decades and the near future will continue to greatly improve both the quality and quantity of patients' lives.They focus on minimally invasive technologies(keyhole surgery) and approaches for deployment of valves,stent-grafts,leadless pacemakers and adaptation of medical devices for destination therapy(assist devices and artificial hearts).In addition,specific blood conduits for the aortic valves together with the aortic arch and the pulmonary valves are considered.These breakthroughs are currently at various stages of development and acceptability.Innovative biomaterials were essential in the development of cardiovascular devices.They were and they still are the essential support for conduction prosthesis,but their place in signal prosthesis is being revisited.Any new development in medical devices has been frequently driven by surgeons and industry.The emergent technologies are introduced by pioneers.The risks and benefits of devices must be continuously reassessed during the lifetime of the implants based upon sound scientific principles of investigation,clinical experience of the users and retrieval programs.     

应用机械臂混凝土3D打印技术的空心曲面建筑物的设计和建造

以机械臂混凝土3D打印系统为硬件平台,以Rhino和Grasshopper为软件平台,研制出一套集设计、模拟、建造一体化的制造平台,并为此制定了设计模式、原则和程序.研究结果表明：机械臂混凝土3D打印技术可以提高空心曲面建筑物加工的精度和效率,能够完成空心曲面建筑物从生形、模拟、优化到建造的一体化制造过程.     

Visualization of the complex structure and stress field inside rock by means of 3D printing technology

Accurate characterization and visualization of the complex inner structure and stress distribution of rocks are of vital significance to solve a variety of underground engineering problems. In this paper, we incorporate several advanced technologies, such as CT scan, three-dimensional（3D） reconstruction, and 3D printing, to produce a physical model representing the natural coal rock that inherently contains complex fractures or joints. We employ 3D frozen stress and photoelastic technologies to characterize and visualize the stress distribution within the fractured rock under uniaxial compression. The 3D printed model presents the fracture structures identical to those of the natural prototype. The mechanical properties of the printed model,including uniaxial compression strength, elastic modulus,and Poisson’s ratio, are testified to be similar to those of the prototype coal rock. The frozen stress and photoelastic tests show that the location of stress concentration and the stress gradient around the discontinuous fractures are in good agreement with the numerical predictions of the real coalsample. The proposed method appears to be capable of visually quantifying the influences of discontinuous,irregular fractures on the strength, deformation, and stress concentration of coal rock. The method of incorporating3 D printing and frozen stress technologies shows a promising way to quantify and visualize the complex fracture structures and their influences on 3D stress distribution of underground rocks, which can also be used to verify numerical simulations.     

3D打印机喷头及工作台振动响应特性分析

寻找高效率、高精度、低成本的陶瓷3D打印机是3D打印技术在陶瓷材料应用方面非常重要的一部分。以柱塞式陶瓷3D打印机为研究对象,建立运动轴简化模型,并利用ANSYS Workbench软件分析柱塞式陶瓷3D打印机运动轴在单轴运动及多轴联动时,喷头及工作台的振动等动态响应数据,并通过打印样件实验,验证了喷头不断变换打印方向时,运动轴启停所造成喷头和工作台的振动,及工作台在下降打印层高时的振动对打印精度的影响微小,运动轴结构稳定,可保障打印精度。     

3D打印在岩石力学研究中的应用现状与展望

基于增材制造原理的3D打印技术因其打印精度高、周期短、可个性化定制、打印材料多样化等优点,在许多研究领域得到广泛应用。在岩石力学研究中,该技术也展现出超越传统研究方法的优势。本文从文献计量角度简要分析了3D打印的发展趋势及其在岩石力学研究中的应用情况,综述该技术在小尺度力学样品与大尺度物理模型试样中的应用现状,分析影响3D打印岩石样品力学强度的因素,总结3D打印制作岩石样品的应用流程及应用效果,最后展望其在岩石力学研究中的应用前景。     

3D打印金属材料研究进展

3D打印技术是快速原型制造技术的一种,也被称为增材制造技术,被誉为"第三次工业革命"的核心技术,其中金属3D打印被认为是将来制造业的主导方向.金属粉末材料是金属打印的物质基础,同时也是3D打印技术发展的突破点.综述了3D打印金属粉体材料的研究现状,重点介绍了钛合金、铝合金、不锈钢、高温合金和镁合金等5种金属粉体材料在3D打印技术中的应用,并对金属粉体材料的运用进行总结和展望.