摘要：Recently,the First Youth Forum of Bio-design&Manufac-turing(BDM)was held in Hangzhou on July 3,***-emician Huayong Yang,Editor-in-Chief of BDM,acted as the Chairman and this conference was jointly sponsored by the School of Mechanical Engineering,Zhejiang Univer-sity,as well as the State Key Laboratory of Fluid Power and Mechatronic Systems.A total of 11 prestigious pro-fessors and researchers from all over the world presented at the conference either online or offline,while more than 150 researchers and students from different universities and research institutes attended and heatedly discussed their research in the fields of bio-design and manufacturing from various perspectives.

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：Dilemmas of current drug screening Recently,multiple technological advancements have been involved in the process of drug research and *** addition,the spending on the relevant projects has doubled in the last 20 years,cumulatively increasing 28%from 2014 to ***,these improvements have not led directly to an obvious increase in feasible drug candidates that successfully passed the clinical *** to the increased spending and stagnant clinical success rate of 10–20%,the efficiency of this project drastically decreased from around 40 drugs per billion in 1950 to 0.6 drugs in 2012.

摘要：Projection-based 3D bioprinting(PBP):a powerful method to fabricate 3D cellular structures Three-dimensional(3D)bioprinting has played an important role in tissue engineering and regenerative medicine areas over the past decade[1].Different from traditional cell cultures in Petri dishes,3D bioprinting can build bionic structures with a better potential to become artificial organ substitutes[2–4].With the development of photocurable biomaterials,the projection-based 3D printing method has been successfully applied in biological research[5,6].

摘要：Introduction Why 3D cell culture urgently needed?Tissue engineering has extremely influenced the development process of basic biological studies and biomedical *** quite a long time,the vast majority of these researches have been relying on the experimental results of conventional two-dimensional(2D)cell culture in flask,petri dish or well ***,these 2D culture results could be very different with or even totally opposite to the actual situations in vivo where cells grow inside a 3D extracellular matrix(ECM).Therefore,3D cell culture has been playing a more and more significant role because of its higher accuracy and authenticity[1–4].

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：As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap *** particular,three-dimensional(3D)bioprinting stands as a landmark in this setting,by promising the precise integration of biomaterials,cells,and bioactive molecules,thus opening up a novel avenue for tissue/organ *** by the editorial board of Bio-Design and Manufacturing,this review brings together a cohort of leading young scientists in China to dissect the core functionalities and evolutionary trajectory of 3D bioprinting,by elucidating the intricate challenges encountered in the manufacturing of transplantable *** further delve into the translational pathway from scientific research to clinical application,emphasizing the imperativeness of establishing a regulatory framework and rigorously enforcing quality-control ***,this review outlines the strategic landscape and innovative achievements of China in this field and provides a comprehensive roadmap for researchers worldwide to propel this field collectively to even greater heights.

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：Micro-/nano-patterns on hydrogels are widely used in cell ***,manufacturing molds with traditional lithography is time-consuming and *** addition,the excessive demolding force can easily damage patterns since biocompatible hydrogels are ultra-soft or ***,we presented a novel method for rapid and mass fabrication of cell ***-precision three-dimensional(3D)printing was used to manufacture a mold with a resolution of 2µm,and the gelatin-based hydrogel was cured by thermal–photo-crosslinking so that the low-concentration and low-substitutionrate hydrogel could be demolded *** found that pre-cooling before illumination made gelatin-based hydrogels resilient due to the partial regain of triple-helix *** this method,arbitrarily customized hydrogel patterns with a feature size of 6–80µm can be fabricated stably and at low *** cardiomyocytes were seeded on ultra-soft hydrogels with parallel groove structures,a consistent and spontaneous beating with 216 beats per minute(BPM)could be observed,approaching the natural beating rate of rat hearts(300 BPM).Overall,this work provides a general scheme for manufacturing cell patterns which has great potential for cell ethology and tissue repair.

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.