摘要：Medical devices are instruments and other tools that act on the human body to aid clinical diagnosis and disease treatment,playing an indispensable role in modern ***,the increasing demand for personalized medical devices poses a significant challenge to traditional manufacturing *** emerging manufacturing technology of three-dimensional(3D)printing as an alternative has shown exciting applications in the medical field and is an ideal method for manufacturing such personalized medical devices with complex ***,the application of this new technology has also brought new risks to medical devices,making 3D-printed devices face severe challenges due to insufficient regulation and the lack of standards to provide guidance to the *** review aims to summarize the current regulatory landscape and existing research on the standardization of 3D-printed medical devices in China,and provide ideas to address these *** focus on the aspects concerned by the regulatory authorities in 3D-printed medical devices,highlighting the quality system of such devices,and discuss the guidelines that manufacturers should follow,as well as the current limitations and the feasible path of regulation and standardization work based on this *** key points of the whole process quality control,performance evaluation methods and the concept of whole life cycle management of 3D-printed medical devices are ***,the significance of regulation and standardization is pointed ***,aspects worthy of attention and future perspectives in this field are discussed.

摘要：Biomedical field has been seeking a feasible standard drug screening system consisting of 3D tumor model array for drug researching due to providing sufficient samples and simulating actual in vivo tumor growth situation,which is still a challenge to rapidly and uniformly establish ***,we propose a novel drug screening system,namely 3D tumor array chip with“layer cake”structure,for drug *** gelatin methacryloyl hydrogel droplets(~0.1μL)containing tumor cells can be automatically deposited on demand with electrohydrodynamic 3D *** conductive membrane is introduced as a chip basement for preventing charges accumulation during fabricating and convenient observing during *** chambers formed by stainless steel and silicon interlayer is convenient to be assembled and *** this chip is compatible with the existing 96-well culturing plate,the drug screening protocols could keep the same as *** properties of this chip,namely printing stability,customizability,accuracy,microenvironment,tumor functionalization,are detailly *** a demonstration,it is applied for screening of epirubicin and paclitaxel with breast tumor cells to confirm the compatibility of the proposed screening system with the traditional screening *** believe this chip will potentially play a significant role in drug evaluation in the future.

摘要：Classification of 3D bioprinting As we mentioned in the last editorial,3D printing,also known as additive manufacturing,could be considered as the reverse process of potato cutting,automatically assembling sliced potato,shredded potato,diced potato to integrity[1].Generally speaking,cell-laden 3D bioprinting can be classified into three types:extrusion-based,droplet-based and photocuring-based bioprinting according to different printing ***-based bioprinting squeezes out continuous hydrogel fibers to set up structures;dropletbased bioprinting generates droplets as the basic unit for biofabrication;and photocuring-based bioprinting utilizes the characteristics of light-sensitive materials,to stack 3D models *** bioprinting approaches own diverse characteristics facing various scenarios and have specific requirements for bioinks.

摘要：Surface topographies such as micrometric edges and grooves have been widely used to improve neuron ***,finding the mechanism of neuron–surface interactions on grooved substrates remains a *** this work,PC12 cells and chick forebrain neurons(CFNs)were cultured on grooved and smooth polyacrylonitrile *** was found that CFNs showed a tendency of growing across groove ridges;while PC12 cells were only observed to grow in the longitudinal direction of *** further investigate these observations,a 3D physical model of axonal outgrowth was *** this model,axon shafts are simulated as elastic 3D beams,accounting for the axon outgrowth as well as the focal contacts between axons and ***,the bending direction of axon tips during groove ridge crossing is governed by the energy minimization *** physical model predicts that axonal groove ridge crossing is contributed by the bending compliance of axons,caused by lower Young’s modulus and smaller *** work will aid the understanding of the mechanisms involved in axonal alignment and elongation of neurons guided by grooved substrates,and the obtained insights can be used to enhance the design of instructive scaffolds for nerve tissue engineering and regeneration applications.

摘要：Tracheal stents are an important form of treatment for benign or malignant central airway ***,the mechanical behavior of current tracheal stents is significantly different from that of the native trachea,which leads to a variety of serious *** this study,inspired by the structure of the native trachea,a wavy non-uniform ligament chiral tracheal stent is proposed,in which J-shaped stress-strain behavior and negative Poisson's ratio response are achieved by replacing the tangential ligament of tetrachiral and anti-tetrachiral hybrid structure with a wavy non-uniform *** the combination of theoretical analysis,finite element analysis and experimental tests,a wide range of desired J-shaped stress-strain curves are explored to mimic the native porcine trachea by tailoring the stent ***,the negative Poisson’s ratio and auxetic diameter curves versus axial strain of the stent are also studied in detail,thus contributing to the enhancement of cross-section ventilation and reducing the migration of the *** novel tracheal stent with a unique microstructure shows a potential to perfectly match the physiological activities of the native trachea and thereby reduce potential complications.

摘要：Three-dimensional(3D)bioprinting is a powerful approach that enables the fabrication of 3D tissue constructs that retain complex biological ***,the dense hydrogel networks that form after the gelation of bioinks often restrict the migration and proliferation of encapsulated ***,a sacrificial microgel-laden bioink strategy was designed for directly bioprinting constructs with mesoscale pore networks(MPNs)for enhancing nutrient delivery and cell *** sacrificial microgel-laden bioink,which contains cell/gelatin methacryloyl(GelMA)mixture and gelled gelatin microgel,is first thermo-crosslinked to fabricate temporary predesigned cell-laden constructs by extrusion bioprinting onto a cold ***,the construct is permanently stabilized through photo-crosslinking of *** MPNs inside the printed constructs are formed after subsequent dissolution of the gelatin *** MPNs allowed for effective oxygen/nutrient diffusion,facilitating the generation of bioactive ***,osteoblast and human umbilical vein endothelial cells encapsulated in the bioprinted large-scale constructs(≥1 cm)with MPNs showed enhanced bioactivity during *** 3D bioprinting strategy based on the sacrificial microgel-laden bioink provided a facile method to facilitate formation of complex tissue constructs with MPNs and set a foundation for future optimization of MPN-based tissue constructs with applications in diverse areas of tissue engineering.

摘要：Graphic abstract Concept of 3D bioprinting 3D printing,also called additive manufacturing,is a layerby-layer manufacturing method,and it has been implemented in a wide variety of areas.3D printing could be treated as the reverse process of potato cutting,automatically assembling the chips or slicing into a potato[1].When this simple idea is met with biomedical engineering,3D bioprinting is born.

摘要：A native organ has heterogeneous structures, sirength, and cell components. It is a big challenge to fabricate organ prototypes with controllable shapes, strength, and cells. Herein, a hybrid method is developed to fabricate organ prototypes with controlled cell deposition by integrating extrusion-based 3D printing, electrospinning, and 3D bioprinting. Multi-scale sheets were first fabricated by 3D printing and electrospinning;then, all the sheets were assembled into organ prototypes by sol-gel react io n duri ng bioprinting. With this method, macroscale structures fabricated by 3D printing ensure the customized structures and provide mechanical support, nanoscale structures fabricated by electrospinning offer a favorable environment for cell growth, and different types of cells with controllable densities are deposited in accurate locations by bioprinting. The results show that L929 mouse fibroblasts encapsulated in the structures exhibited over 90% survival within 10 days and maintai ned a high proliferation rate. furthermore, the cells grew in spherical shapes first and then migrated to the nano scale fibers showing stretched morphology. Additionally, a branched vascular structure was successfully fabricated using the presented method. Compared with other methods, this strategy offers an easy way to simultancously realize the shape control, nanolibrous structures, and cell accurate deposition, which will have potemidi applications in tissue cngineering.

摘要：为了进一步提升电主轴的加工性能,以常见的A02型电主轴为分析对象,使用热膨胀系数小以及减振性能优异的碳纤维材料替换芯轴的不同部位,以此设计4种碳纤维-金属复合芯轴,探讨其对A02型电主轴的影响。通过有限元分析,对4种碳纤维-金属复合芯轴和常规钢芯轴的动态特性和热特性进行评估。结果表明:全碳纤维芯轴的性能最佳,而心部碳纤维芯轴可以在避免使用大量碳纤维材料的基础上实现与全碳纤维芯轴相近的效果;外侧碳纤维芯轴具有成熟的加工工艺,可以直接进行加工试验。列举了几种碳纤维-金属复合芯轴已有或具备可行性的加工方案,为碳纤维材料与电主轴结构更好地结合提供参考。

摘要：This paper proposes an additive nanomanufacturing approach to fabricate a personalized lab-on-a-chip fluorescent peptide nanoparticles (f-PNPs) array for simultaneous multi-biomarker detection that can be used in Alzheimer’s disease (AD) diagnosis. We will discuss optimization techniques for the additive nanomanufacturing process in terms of reliability, yield and manufacturing efficiency. One contribution of this paper lies in utilization of additive nanomanufacturing techniques to fabricate a patient-specific customize-designed lab-on-a-chip device for personalized AD diagnosis, which remains a major challenge for biomedical engineering. Through the integrated bio-design and bio-manufacturing process, doctor’s check-up and computer-aided customized design are integrated into the lab-on-a-chip array for patient-specific AD diagnosis. In addition, f-PNPs with targeting moieties for personalized AD biomarkers will be self-assembled onto the customized lab-on-a-chip through the additive nanomanufacturing process, which has not been done before. Another contribution of this research is the personalized lab-on-a-chip f-PNPs array for AD diagnosis utilizing limited human blood. Blood-based AD assessment has been described as “the holy grail” of early AD detection. This research created the computer-aided design, fabrication through additive nanomanufacturing, and validation of the f-PNPs array for AD diagnosis. This is a highly interdisciplinary research contributing to nanotechnology, biomaterials, and biomedical engineering for neurodegenerative disease. The conceptual work is preliminary with intent to introduce novel techniques to the application. Large-scale manufacturing based on the proposed framework requires extensive validation and optimization.