A liquid Li divertor is a promising alternative for future fusion devices.In this work a new divertor model is proposed,which is processed by 3D-printing technology to accurately control the size of the internal capil...A liquid Li divertor is a promising alternative for future fusion devices.In this work a new divertor model is proposed,which is processed by 3D-printing technology to accurately control the size of the internal capillary structure.At a steady-state heat load of 10 MW m^(-2),the thermal stress of the tungsten target is within the bearing range of tungsten by finite-element simulation.In order to evaluate the wicking ability of the capillary structure,the wicking process at 600℃ was simulated by FLUENT.The result was identical to that of the corresponding experiments.Within 1 s,liquid lithium was wicked to the target surface by the capillary structure of the target and quickly spread on the target surface.During the wicking process,the average wicking mass rate of lithium should reach 0.062 g s^(-1),which could even supplement the evaporation requirement of liquid lithium under an environment>950℃.Irradiation experiments under different plasma discharge currents were carried out in a linear plasma device(SCU-PSI),and the evolution of the vapor cloud during plasma irradiation was analyzed.It was found that the target temperature tends to plateau despite the gradually increased input current,indicating that the vapor shielding effect is gradually enhanced.The irradiation experiment also confirmed that the 3D-printed tungsten structure has better heat consumption performance than a tungsten mesh structure or multichannel structure.These results reveal the application potential and feasibility of a 3D-printed porous capillary structure in plasma-facing components and provide a reference for further liquid-solid combined target designs.展开更多
Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailora...Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailorable structures and compositions,diverse functionalities,and well-controlled pore/size distribution.However,most developed MOFs are in powder forms,which still have some technical challenges,including abrasion,dustiness,low packing densities,clogging,mass/heat transfer limitation,environmental pollution,and mechanical instability during the packing process,that restrict their applicability in industrial applications.Therefore,in recent years,attention has focused on techniques to convert MOF powders into macroscopic materials like beads,membranes,monoliths,gel/sponges,and nanofibers to overcome these challenges.Three-dimensional(3D)printing technology has achieved much interest because it can produce many high-resolution macroscopic frameworks with complex shapes and geometries from digital models.Therefore,this review summarizes the combination of different 3D printing strategies with MOFs and MOF-based materials for fabricating 3D-printed MOF monoliths and their environmental applications,emphasizing water treatment and gas adsorption/separation applications.Herein,the various strategies for the fabrication of 3D-printed MOF monoliths,such as direct ink writing,seed-assisted in-situ growth,coordination replication from solid precursors,matrix incorporation,selective laser sintering,and digital light processing,are described with the relevant examples.Finally,future directions and challenges of 3D-printed MOF monoliths are also presented to better plan future trajectories in the shaping of MOF materials with improved control over the structure,composition,and textural properties of 3D-printed MOF monoliths.展开更多
Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method...Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method,has been reported.In this method,the customized precursor paste and programmable shape are two main advantages.Here,we have put forward a new way to customize the YBCO 3D-printing precursor paste which is doped with Al_(2)O_(3)nanoparticles to obtain YBCO with higher thermal conductivity.The great rheological properties of precursor paste after being doped with Al_(2)O_(3)nanoparticles can help the macroscopic YBCO samples with high thermal conductivity fabricated stably with high crystalline and lightweight properties.Test results show that the peak thermal conductivity of Al_(2)O_(3)-doped YBCO can reach twice as much as pure YBCO,which makes a great effort to reduce the quench propagation speed.Based on the microstructure analysis,one can find that the thermal conductivity of Al_(2)O_(3)-doped YBCO has been determined by its components and microstructures.In addition,a macroscopic theoretical model has been proposed to assess the thermal conductivity of different microstructures,whose calculated results take good agreement with the experimental results.Meanwhile,a microstructure with high thermal conductivity has been found.Finally,a macroscopic YBCO bulk with the presented high thermal conductivity microstructure has been fabricated by the Al_(2)O_(3)-doped method.Compared with YBCO fabricated by the traditional 3D-printed,the Al_(2)O_(3)-doped structural YBCO bulks present excellent heat transfer performances.Our customized design of 3D-printing precursor pastes and novel concept of structural design for enhancing the thermal conductivity of YBCO superconducting material can be widely used in other DIW 3D-printing materials.展开更多
In the current study poly(lactic acid)PLA composites with a 3 wt%and 5 wt%of nanofibrillated cellulose(NFC)were produced by 3D-printing method.An enzymatic pretreatment coupled with mechanical fibrillation in a twin s...In the current study poly(lactic acid)PLA composites with a 3 wt%and 5 wt%of nanofibrillated cellulose(NFC)were produced by 3D-printing method.An enzymatic pretreatment coupled with mechanical fibrillation in a twin screw extruder was used to produce high consistency NFC.Scanning electron microscopy(SEM)equipped with Fibermetric software,FASEP fiber length distribution analysis,Furrier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),tensile tests,impact tests and differential scanning calorimetry were used to characterize NFC and PLA/NFC composites.The results of the fiber length and width measurements together with the results of the SEM analysis showed that enzymatic hydrolysis coupled with a twin screw extrusion could effectively reduce the diameter and length of cellulose fibers.The produced NFC consisted of microand nanosized fibers entangled in a characteristic 3D-network.Based on the FT-IR analysis,no new bonds were formed during the enzymatic hydrolysis or fibrillation process.The TGA analysis confirmed that produced NFC can be used in hightemperature extrusion processing without NFC degradation.During the PLA/NFC composites preparation the NFC agglomerates were formed,which negatively influenced PLA/NFC composites impact properties.The slightly improved tensile strength and elastic modulus were reported for all composites when compared to the neat PLA.The elongation at break was not affected by the NFC addition.No significant differences in thermal stability were detectable among composites nor in comparation with the neat PLA.However,the crystallinity degree of the composite containing 5 wt%NFC was increased in respect to the neat PLA.展开更多
Living and/or non-living animal models are often used as stimuli to observe the behavioral responses of the target animals.In the past,parasites,predators,and harmless controls have been used to test host anti-parasit...Living and/or non-living animal models are often used as stimuli to observe the behavioral responses of the target animals.In the past,parasites,predators,and harmless controls have been used to test host anti-parasitism defense behavior,and their taxidermy specimens have been widely used as a set of standard methods for the study of avian brood parasitism.In recent years,with the rapid development of 3D-printing technology,3D-printed bird models are expected to be applied as a standard method in the study of avian brood parasitism.To evaluate the use of 3D-printed models,this study tests the reaction of Oriental Reed Warbler(Acrocephalus orientalis)towards predators,parasites,or controls,and compares the reaction among different nest intruders and between taxidermy specimens and 3D-printed animal models.It was found that the Oriental Reed Warbler responded most aggressively to the parasite,followed by predator,and finally the control;the results were consistent between the reaction to taxidermy specimens and 3D-printed animal models,indicating that 3D-printed models could serve as a substitute for taxidermy specimens.We propose a series of advantages of using 3D-printed models and suggest them to be a standard method for widespread use in future studies of avian brood parasitism.展开更多
To improve the strength of carbon fiber(CF) reinforced Polycaprolactam(PA6) composites, controlled amounts of carbon nanotubes(CNTs) were grafted onto the surface of CF to prepare the hybrid reinforcement(HR). We used...To improve the strength of carbon fiber(CF) reinforced Polycaprolactam(PA6) composites, controlled amounts of carbon nanotubes(CNTs) were grafted onto the surface of CF to prepare the hybrid reinforcement(HR). We used HR to fabricate laminate and H-sample to test the interfacial bonding strength(IBS) of the composites by means of a novel process called three-dimensional printed molding(3 D-PM). By using the melt drop printing method, we measured the contact angles between PA6 and CF(without sizing) and between PA6 and HR. The IBS and the mechanical properties of the composites were obtained by the tensile test. The experimental result indicated that CF grafted by 0.25% weight fraction of CNT or more could develop a special microstructure similar to the micro-pits on the surface of CF, which improved the wettability of CF and PA6 due to the increased surface area and the roughness of CF. When the weight fraction of CNT reached 0.25%, the IBS increased by 41.8%, the tensile strength by 130%, and the interfacial shear strength(IFSS) by 238%. The interfacial dimple fracture was observed by Scanning Electron Microscope(SEM), which revealed that the composites were able to absorb more deforming energy before fracture. The modified surface microstructure of CF would prevent crack propagation at the interface and increase the mechanical properties of thermoplastic composites(TPCs).展开更多
Postoperative anatomical reconstruction and prevention of local recurrence after tumor resection are two vital clinical challenges in osteosarcoma treatment.A three-dimensional(3D)-printed porous Ti6Al4V scaffold(3DTi...Postoperative anatomical reconstruction and prevention of local recurrence after tumor resection are two vital clinical challenges in osteosarcoma treatment.A three-dimensional(3D)-printed porous Ti6Al4V scaffold(3DTi)is an ideal material for reconstructing critical bone defects with numerous advantages over traditional implants,including a lower elasticity modulus,stronger bone-implant interlock,and larger drug-loading space.Simvastatin is a multitarget drug with anti-tumor and osteogenic potential;however,its efficiency is unsatisfactory when delivered systematically.Here,simvastatin was loaded into a 3DTi using a thermosensitive poly(lactic-co-gly-colic)acid(PLGA)-polyethylene glycol(PEG)-PLGA hydrogel as a carrier to exert anti-osteosarcoma and oste-ogenic effects.Newly constructed simvastatin/hydrogel-loaded 3DTi(Sim-3DTi)was comprehensively appraised,and its newfound anti-osteosarcoma mechanism was explained.Specifically,in a bone defect model of rabbit condyles,Sim-3DTi exhibited enhanced osteogenesis,bone in-growth,and osseointegration compared with 3DTi alone,with greater bone morphogenetic protein 2 expression.In our nude mice model,simvastatin loading reduced tumor volume by 59%-77%without organic damage,implying good anti-osteosarcoma activity and biosafety.Furthermore,Sim-3DTi induced ferroptosis by upregulating transferrin and nicotinamide adenine dinucleotide phosphate oxidase 2 levels in osteosarcoma both in vivo and in vitro.Sim-3DTi is a promising osteogenic bone substitute for osteosarcoma-related bone defects,with a ferroptosis-mediated anti-osteosarcoma effect.展开更多
Here,we report the production of 3D-printed MoS_(2)/Ni electrodes(3D-MoS_(2)/Ni)with longterm stability and excellent performance by the selective laser melting(SLM)technique.As a cathode,the obtained 3D-MoS_(2)/Ni co...Here,we report the production of 3D-printed MoS_(2)/Ni electrodes(3D-MoS_(2)/Ni)with longterm stability and excellent performance by the selective laser melting(SLM)technique.As a cathode,the obtained 3D-MoS_(2)/Ni could maintain a degradation rate above 94.0%for forfenicol(FLO)when repeatedly used 50 times in water.We also found that the removal rate of FLO by 3D-MoS_(2)/Ni was about 12 times higher than that of 3D-printed pure Ni(3D-Ni),attributed to the improved accessibility of H^(*).In addition,the electrochemical characterization results showed that the electrochemically active surface area of the 3D-MoS_(2)/Ni electrode is about 3-fold higher than that of the 3D-Ni electrode while the electrical resistance is 4 times lower.Based on tert-butanol suppression,electron paramagnetic resonance and triple quadrupole mass spectrometer experiments,a“dual path”mechanism and possible degradation pathway for the dechlorination of FLO by 3D-MoS_(2)/Ni were proposed.Furthermore,we also investigated the impacts of the cathode potential and the initial pH of the solution on the degradation of FLO.Overall,this study reveals that the SLM 3D printing technique is a promising approach for the rapid fabrication of high-stability metal electrodes,which could have broad application in the control of water contaminants in the environmental field.展开更多
The integrative regeneration of both articular cartilage and subchondral bone remains an unmet clinical need due to the difficulties of mimicking spatial complexity in native osteochondral tissues for artificial impla...The integrative regeneration of both articular cartilage and subchondral bone remains an unmet clinical need due to the difficulties of mimicking spatial complexity in native osteochondral tissues for artificial implants.Layer-by-layer fabrication strategies,such as 3D printing,have emerged as a promising technology replicating the stratified zonal architecture and varying microstructures and mechanical properties.However,the dynamic and circulating physiological environments,such as mass transportation or cell migration,usually distort the pre-confined biological properties in the layered implants,leading to undistinguished spatial variations and subsequently inefficient regenerations.This study introduced a biomimetic calcified interfacial layer into the scaffold as a compact barrier between a cartilage layer and a subchondral bone layer to facilitate osteogenic-chondrogenic repair.The calcified interfacial layer consisting of compact polycaprolactone(PCL),nano-hydroxyapatite,and tasquinimod(TA)can physically and biologically separate the cartilage layer(TA-mixed,chondrocytes-load gelatin methacrylate)from the subchondral bond layer(porous PCL).This introduction preserved the as-designed independent biological environment in each layer for both cartilage and bone regeneration,successfully inhibiting vascular invasion into the cartilage layer and preventing hyaluronic cartilage calcification owing to devascularization of TA.The improved integrative regeneration of cartilage and subchondral bone was validated through gross examination,micro-computed tomography(micro-CT),and histological and immunohistochemical analyses based on an in vivo rat model.Moreover,gene and protein expression studies identified a key role of Caveolin(CAV-1)in promoting angiogenesis through the Wnt/β-catenin pathway and indicated that TA in the calcified layer blocked angiogenesis by inhibiting CAV-1.展开更多
Nonlinear flow behavior of fluids through three-dimensional(3D)discrete fracture networks(DFNs)considering effects of fracture number,surface roughness and fracture aperture was experimentally and numerically investig...Nonlinear flow behavior of fluids through three-dimensional(3D)discrete fracture networks(DFNs)considering effects of fracture number,surface roughness and fracture aperture was experimentally and numerically investigated.Three physical models of DFNs were 3D-printed and then computed tomography(CT)-scanned to obtain the specific geometry of fractures.The validity of numerically simulating the fluid flow through DFNs was verified via comparison with flow tests on the 3D-printed models.A parametric study was then implemented to establish quantitative relations between the coefficients/parameters in Forchheimer’s law and geometrical parameters.The results showed that the 3D-printing technique can well reproduce the geometry of single fractures with less precision when preparing complex fracture networks,numerical modeling precision of which can be improved via CT-scanning as evidenced by the well fitted results between fluid flow tests and numerical simulations using CT-scanned digital models.Streamlines in DFNs become increasingly tortuous as the fracture number and roughness increase,resulting in stronger inertial effects and greater curvatures of hydraulic pressure-low rate relations,which can be well characterized by the Forchheimer’s law.The critical hydraulic gradient for the onset of nonlinear flow decreases with the increasing aperture,fracture number and roughness,following a power function.The increases in fracture aperture and number provide more paths for fluid flow,increasing both the viscous and inertial permeabilities.The value of the inertial permeability is approximately four orders of magnitude greater than the viscous permeability,following a power function with an exponent a of 3,and a proportional coefficient b mathematically correlated with the geometrical parameters.展开更多
The classical 3D-printed scaffolds have attracted enormous interests in bone regeneration due to the customized structural and mechanical adaptability to bone defects.However,the pristine scaffolds still suffer from t...The classical 3D-printed scaffolds have attracted enormous interests in bone regeneration due to the customized structural and mechanical adaptability to bone defects.However,the pristine scaffolds still suffer from the absence of dynamic and bioactive microenvironment that is analogous to natural extracellular matrix(ECM)to regulate cell behaviour and promote tissue regeneration.To address this challenge,we develop a black phosphorus nanosheets-enabled dynamic DNA hydrogel to integrate with 3D-printed scaffold to build a bioactive gel-scaffold construct to achieve enhanced angiogenesis and bone regeneration.The black phosphorus nanosheets reinforce the mechanical strength of dynamic self-healable hydrogel and endow the gel-scaffold construct with preserved protein binding to achieve sustainable delivery of growth factor.We further explore the effects of this activated construct on both human umbilical vein endothelial cells(HUVECs)and mesenchymal stem cells(MSCs)as well as in a critical-sized rat cranial defect model.The results confirm that the gel-scaffold construct is able to promote the growth of mature blood vessels as well as induce osteogenesis to promote new bone formation,indicating that the strategy of nano-enabled dynamic hydrogel integrated with 3D-printed scaffold holds great promise for bone tissue engineering.展开更多
Facile and rapid 3D fabrication of strong,bioactive materials can address challenges that impede repair of large-to-massive rotator cuff tears including personalized grafts,limited mechanical support,and inadequate ti...Facile and rapid 3D fabrication of strong,bioactive materials can address challenges that impede repair of large-to-massive rotator cuff tears including personalized grafts,limited mechanical support,and inadequate tissue regeneration.Herein,we developed a facile and rapid methodology that generates visible light-crosslinkable polythiourethane(PHT)pre-polymer resin(~30 min at room temperature),yielding 3D-printable scaffolds with tendon-like mechanical attributes capable of delivering tenogenic bioactive factors.Ex vivo characterization confirmed successful fabrication,robust human supraspinatus tendon(SST)-like tensile properties(strength:23 MPa,modulus:459 MPa,at least 10,000 physiological loading cycles without failure),excellent suture retention(8.62-fold lower than acellular dermal matrix(ADM)-based clinical graft),slow degradation,and controlled release of fibroblast growth factor-2(FGF-2)and transforming growth factor-β3(TGF-β3).In vitro studies showed cytocompatibility and growth factor-mediated tenogenic-like differentiation of mesenchymal stem cells.In vivo studies demonstrated biocompatibility(3-week mouse subcutaneous implantation)and ability of growth factor-containing scaffolds to notably regenerate at least 1-cm of tendon with native-like biomechanical attributes as uninjured shoulder(8-week,large-to-massive 1-cm gap rabbit rotator cuff injury).This study demonstrates use of a 3D-printable,strong,and bioactive material to provide mechanical support and pro-regenerative cues for challenging injuries such as large-to-massive rotator cuff tears.展开更多
Fucoidan,a sulfate polysaccharide obtained from brown seaweed,has various bioactive properties,including anti-inflammatory,anti-cancer,anti-viral,anti-oxidant,anti-coagulant,anti-thrombotic,anti-angiogenic,and anti-He...Fucoidan,a sulfate polysaccharide obtained from brown seaweed,has various bioactive properties,including anti-inflammatory,anti-cancer,anti-viral,anti-oxidant,anti-coagulant,anti-thrombotic,anti-angiogenic,and anti-Helicobacter pylori properties.However,the effects of low-molecular-weight fucoidan(LMW-F)on melanoma cell lines and three dimensional(3D)cell culture models are not well understood.This study aimed to investigate the effects of LMW-F on A375 human melanoma cells and cryopreserved biospecimens derived from patients with advanced melanoma.Ultrasonic wave was used to fragment fucoidan derived from Fucus vesiculosus into smaller LMW-F.MTT and live/dead assays showed that LMW-F inhibited cell proliferation in both A375 cells and patientderived melanoma explants in a 3D-printed collagen scaffold.The PTEN/AKT pathway was found to be involved in the anti-melanoma effects of fucoidan.Western blot analysis revealed that LMW-F reduced the phosphorylation of Bcl-2 at Thr 56,which was associated with the prevention of anti-apoptotic activity of cancer cells.Our findings suggested that LMW-F could enhance anti-melanoma chemotherapy and improve the outcomes of patients with melanoma resistance.展开更多
Three-dimensional (3D) printing technology is driving forward the progresses of various engineering fields, including tissue engineering. However, the pristine 3D-printed scaffolds usually lack robust functions in sti...Three-dimensional (3D) printing technology is driving forward the progresses of various engineering fields, including tissue engineering. However, the pristine 3D-printed scaffolds usually lack robust functions in stimulating desired activity for varied regeneration applications. In this study, we combined the two-dimensional (2D) hetero-nanostructures and immuno-regulative interleukin-4 (IL-4) cytokines for the functionalization of 3D-printed scaffolds to achieve a pro-healing immuno-microenvironment for optimized bone injury repair. The 2D hetero-nanostructure consists of graphene oxide (GO) layers, for improved cell adhesion, and black phosphorous (BP) nanosheets, for the continuous release of phosphate ions to stimulate cell growth and osteogenesis. In addition, the 2D hetero-nanolayers facilitated the adsorption of large content of immuno-regulative IL-4 cytokines, which modulated the polarization of macrophages into M2 phenotype. After in vivo implantation in rat, the immuno-functioned 3D-scaffolds achieved in vivo osteo-immunomodulation by building a pro-healing immunological microenvironment for better angiogenesis and osteogenesis in the defect area and thus facilitated bone regeneration. These results demonstrated that the immuno-functionalization of 3D-scaffolds with 2D hetero-nanostructures with secondary loading of immuno-regulative cytokines is an encouraging strategy for improving bone regeneration.展开更多
The architecture and surface modifications have been regarded as effective methods to enhance the bi-ological response of biomaterials in bone tissue engineering.The porous architecture of the implanta-tion was essent...The architecture and surface modifications have been regarded as effective methods to enhance the bi-ological response of biomaterials in bone tissue engineering.The porous architecture of the implanta-tion was essential conditions for bone regeneration.Meanwhile,the design of biomimetic hydroxyap-atite(HAp)coating on porous scaffolds was demonstrated to strengthen the bioactivity and stimulate osteogenesis.However,bioactive bio-ceramics such asβ-tricalcium phosphate(β-TCP)and calcium sili-cate(CS)with superior apatite-forming ability were reported to present better osteogenic activity than that of HAp.Hence in this study,3D-printed interconnected porous bioactive ceramicsβ-TCP/CS scaf-fold was fabricated and the biomimetic HAp apatite coating were constructed in situ via hydrothermal reaction,and the effects of HAp apatite layer on the fate of mouse bone mesenchymal stem cells(mBM-SCs)and the potential mechanisms were explored.The results indicated that HAp apatite coating en-hanced cell proliferation,alkaline phosphatase(ALP)activity,and osteogenic gene expression.Further-more,PI3K/AKT/mTOR signaling pathway is proved to have an important impact on cellular functions.The present results demonstrated that the key molecules of phosphatidylinositol 3-kinase(PI3K),protein kinase B(AKT)and mammalian target of rapamycin(mTOR)were activated after the biomimetic hydrox-yapatite coating were constructed on the 3D-printed ceramic scaffolds.Besides,the activated influence on the protein expression of Runx2 and BMP2 could be suppressed after the treatment of inhibitor HY-10358.In vivo studies showed that the constructed HAp coating promoted bone formation and strengthen the bone quality.These results suggest that biomimetic HAp coating constructed on the 3D-printed bioac-tive composite scaffolds could strengthen the bioactivity and the obtained biomimetic multi-structured scaffolds might be a potential alternative bone graft for bone regeneration.展开更多
The increased number of mastectomies,combined with rising patient expectations for cosmetic and psychosocial outcomes,has necessitated the use of adipose tissue restoration techniques.However,the therapeutic effect of...The increased number of mastectomies,combined with rising patient expectations for cosmetic and psychosocial outcomes,has necessitated the use of adipose tissue restoration techniques.However,the therapeutic effect of current clinical strategies is not satisfying due to the high demand of personalized customization and the timely vascularization in the process of adipose regeneration.Here,a composite hydrogel scaffold was prepared by three-dimensional(3D)printing technology,applying gelatin methacrylate anhydride(GelMA)as printing ink and calcium silicate(CS)bioceramic as an active ingredient for breast adipose tissue regeneration.The in vitro experiments showed that the composite hydrogel scaffolds could not only be customized with controllable architectures,but also significantly stimulated both 3T3-L1 preadipocytes and human umbilical vein endothelial cells in multiple cell behaviors,including cell adhesion,proliferation,migration and differentiation.Moreover,the composite scaffold promoted vascularized adipose tissue restoration under the skin of nude mice in vivo.These findings suggest that 3D-printed GelMA/CS composite scaffolds might be a good candidate for adipose tissue engineering.展开更多
Bi_(2)Te_(3)-based materials were prepared by direct ink writing(DIW)3D printing and their microstructure and thermoelectric properties were investigated with an emphasis on the effect of the content of DMF and Te/Se ...Bi_(2)Te_(3)-based materials were prepared by direct ink writing(DIW)3D printing and their microstructure and thermoelectric properties were investigated with an emphasis on the effect of the content of DMF and Te/Se addition.As the mass ratio of DMF in the composition increased from 6.5%to 8.0%(in mass),the electrical conductivity deteriorated because of the corresponding increased porosity and organic remains in the samples.However,the volatilization of DMF would reduce the fluidity of the slurry.Thus,thermoelectric slurry with 7.0%DMF is the most suitable mass ratio for 3D printing.Additionally,adding Te in the p-type Bi0.4Sb1.6Te3 and adding Se in the n-type Bi2Te2.6Se0.4 have significantly improved their electrical conductivity due to the increased carrier concentration and mobility.Combining with the moderate Seebeck coefficient(~200 mV/K),high power factors with~802 mW·m^(-1)·K^(-2)and 1266 mW·m^(-1)·K^(-2)were obtained for the n-type Bi_(2)Te_(2.6)Se_(0.4)þ10%Se and p-type Bi_(0.4)Sb_(1.6)Te_(3)þ7%Te,respectively,which result in the final relatively high zT values of 0.68 at 573 K and 0.56 at 330 K for ntype and p-type 3D-printed samples.展开更多
Highly deformable bodies are essential for numerous types of applications in all sorts of environments. Joint-like structures comprising a ball and socket joint have many degrees of freedom that allow mobility of many...Highly deformable bodies are essential for numerous types of applications in all sorts of environments. Joint-like structures comprising a ball and socket joint have many degrees of freedom that allow mobility of many biomimetic structures. Recently, soft robots are favored over rigid structures for their highly compliant material, high-deformation properties at low forces, and ability to operate in di fficult environments. However, it is still challenging to fabricate complex designs that satisfy application constraints due to the combined e ffects of material properties, actuation method, and structural geometry on the performance of the soft robot. Therefore, a combination of a rigid joint and a soft body can help achieve modular robots with fully functional body morphology. Yet, the fabrication of soft parts requires extensive molding for complex shapes, which comprises several processes and can be time-consuming. In addition, molded connections between extremely soft materials and hard materials can be critical failing points. In this paper, we present a functionally graded 3D-printed joint-like structure actuated by novel contractile actuators. Functionally graded materials (FGMs) via 3D printing allow for extensive material property enhancement and control which warrant tunable functionalities of the system. The 3D-printed structure is made of 3 rigid ball and socket joints connected in series and actuated by integrating twisted and coiled polymer fishing line ( TCPFL) actuators, which are con fined in the FGM accordion-shaped channels. The implementation of the untethered T CPFL actuation system can be highly bene ficial for deployment in environments that require low vibrations and silent actuation. The fishing line TCP actuators produce an actuation strain up to 40% and bend the joint up to 40° in any direction. The T CPFL can be actuated individually or as a group to control the bending trajectory of the modular joint, which is bene ficial when deployed in areas that contain small crevices. Obtaining complex modes of bending, the FGM multidirectional joint demonstrated a great potential to achieve di fferent functionalities such as crawling, rolling, swimming, or underwater exploration.展开更多
BACKGROUND Hernia is a common condition requiring abdominal surgery.The current standard treatment for hernia is tension-free repair using meshes.Globally,more than 200 new types of meshes are licensed each year.Howev...BACKGROUND Hernia is a common condition requiring abdominal surgery.The current standard treatment for hernia is tension-free repair using meshes.Globally,more than 200 new types of meshes are licensed each year.However,their clinical applications are associated with a series of complications,such as recurrence(10%-24%)and infection(0.5%-9.0%).In contrast,3D-printed meshes have significantly reduced the postoperative complications in patients.They have also shortened operating time and minimized the loss of mesh materials.In this study,we used the myopectineal orifice(MPO)data obtained from preoperative computer tomography(CT)-based 3D reconstruction for the production of 3D-printed biologic meshes.AIM To investigate the application of multislice spiral CT-based 3D reconstruction technique in 3D-printed biologic mesh for hernia repair surgery.METHODS We retrospectively analyzed 60 patients who underwent laparoscopic tension-free repair for inguinal hernia in the Department of General Surgery of the First Hospital of Shanxi Medical University from September 2019 to December 2019.This study included 30 males and 30 females,with a mean age of 40±5.6 years.Data on the MPO were obtained from preoperative CT-based 3D reconstruction as well as from real-world intraoperative measurements for all patients.Anatomic points were set for the purpose of measurement based on the definition of MPO:A:The pubic tubercle;B:Intersection of the horizontal line extending from the summit of the inferior edge of the internal oblique and transversus abdominis and the outer edge of the rectus abdominis,C:Intersection of the horizontal line extending from the summit of the inferior edge of the internal oblique and transversus abdominis and the inguinal ligament,D:Intersection of the iliopsoas muscle and the inguinal ligament,and E:Intersection of the iliopsoas muscle and the superior pubic ramus.The distance between the points was measured.All preoperative and intraoperative data were analyzed using the t test.Differences with P<0.05 were considered significant in comparative analysis.RESULTS The distance between points AB,AC,BC,DE,and AE based on preoperative and intraoperative data was 7.576±0.212 cm vs 7.573±0.266 cm,7.627±0.212 cm vs 7.627±0.212 cm,7.677±0.229 cm vs 7.567±0.786 cm,7.589±0.204 cm vs 7.512±0.21 cm,and 7.617±0.231 cm vs 7.582±0.189 cm,respectively.All differences were not statistically significant(P>0.05).CONCLUSION The use of multislice spiral CT-based 3D reconstruction technique before hernia repair surgery allows accurate measurement of data and relationships of different anatomic sites in the MPO region.This technique can provide precise data for the production of 3D-printed biologic meshes.展开更多
A study was conducted to evaluate the current production capabilities of the Mark One? 3D printer in printing carbon fibre reinforced thermoplastic (CFRTP) tensile test specimens according to the JIS K 7073 by making ...A study was conducted to evaluate the current production capabilities of the Mark One? 3D printer in printing carbon fibre reinforced thermoplastic (CFRTP) tensile test specimens according to the JIS K 7073 by making use of fused deposition modelling. Several different types of CFRTP tensile test specimens are printed and are tensile tested in the longitudinal direction to obtain an overview of the mechanical properties of 3D printed CFRTP material. These properties are compared with the literature values known for composite materials to see if these agree. The main goal of this research is to increase the knowledge of the 3D printing process of CFRTP and to later use this knowledge to further improve the 3D printing process to obtain stronger 3D printed CFRTP materials.展开更多
基金funded by the China Postdoctoral Science Foundation(No.2019M663487)the National Key Research and Development Program of China(No.2022YFE03130000)。
文摘A liquid Li divertor is a promising alternative for future fusion devices.In this work a new divertor model is proposed,which is processed by 3D-printing technology to accurately control the size of the internal capillary structure.At a steady-state heat load of 10 MW m^(-2),the thermal stress of the tungsten target is within the bearing range of tungsten by finite-element simulation.In order to evaluate the wicking ability of the capillary structure,the wicking process at 600℃ was simulated by FLUENT.The result was identical to that of the corresponding experiments.Within 1 s,liquid lithium was wicked to the target surface by the capillary structure of the target and quickly spread on the target surface.During the wicking process,the average wicking mass rate of lithium should reach 0.062 g s^(-1),which could even supplement the evaporation requirement of liquid lithium under an environment>950℃.Irradiation experiments under different plasma discharge currents were carried out in a linear plasma device(SCU-PSI),and the evolution of the vapor cloud during plasma irradiation was analyzed.It was found that the target temperature tends to plateau despite the gradually increased input current,indicating that the vapor shielding effect is gradually enhanced.The irradiation experiment also confirmed that the 3D-printed tungsten structure has better heat consumption performance than a tungsten mesh structure or multichannel structure.These results reveal the application potential and feasibility of a 3D-printed porous capillary structure in plasma-facing components and provide a reference for further liquid-solid combined target designs.
文摘Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailorable structures and compositions,diverse functionalities,and well-controlled pore/size distribution.However,most developed MOFs are in powder forms,which still have some technical challenges,including abrasion,dustiness,low packing densities,clogging,mass/heat transfer limitation,environmental pollution,and mechanical instability during the packing process,that restrict their applicability in industrial applications.Therefore,in recent years,attention has focused on techniques to convert MOF powders into macroscopic materials like beads,membranes,monoliths,gel/sponges,and nanofibers to overcome these challenges.Three-dimensional(3D)printing technology has achieved much interest because it can produce many high-resolution macroscopic frameworks with complex shapes and geometries from digital models.Therefore,this review summarizes the combination of different 3D printing strategies with MOFs and MOF-based materials for fabricating 3D-printed MOF monoliths and their environmental applications,emphasizing water treatment and gas adsorption/separation applications.Herein,the various strategies for the fabrication of 3D-printed MOF monoliths,such as direct ink writing,seed-assisted in-situ growth,coordination replication from solid precursors,matrix incorporation,selective laser sintering,and digital light processing,are described with the relevant examples.Finally,future directions and challenges of 3D-printed MOF monoliths are also presented to better plan future trajectories in the shaping of MOF materials with improved control over the structure,composition,and textural properties of 3D-printed MOF monoliths.
基金supported by the Fund of Natural Science Foundation of China(No.11872196,12232005)supported by the Outstanding Postgraduate‘Innovation Star’Fund for Distinguished of Gansu Province(No.2021CXZX-032).
文摘Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method,has been reported.In this method,the customized precursor paste and programmable shape are two main advantages.Here,we have put forward a new way to customize the YBCO 3D-printing precursor paste which is doped with Al_(2)O_(3)nanoparticles to obtain YBCO with higher thermal conductivity.The great rheological properties of precursor paste after being doped with Al_(2)O_(3)nanoparticles can help the macroscopic YBCO samples with high thermal conductivity fabricated stably with high crystalline and lightweight properties.Test results show that the peak thermal conductivity of Al_(2)O_(3)-doped YBCO can reach twice as much as pure YBCO,which makes a great effort to reduce the quench propagation speed.Based on the microstructure analysis,one can find that the thermal conductivity of Al_(2)O_(3)-doped YBCO has been determined by its components and microstructures.In addition,a macroscopic theoretical model has been proposed to assess the thermal conductivity of different microstructures,whose calculated results take good agreement with the experimental results.Meanwhile,a microstructure with high thermal conductivity has been found.Finally,a macroscopic YBCO bulk with the presented high thermal conductivity microstructure has been fabricated by the Al_(2)O_(3)-doped method.Compared with YBCO fabricated by the traditional 3D-printed,the Al_(2)O_(3)-doped structural YBCO bulks present excellent heat transfer performances.Our customized design of 3D-printing precursor pastes and novel concept of structural design for enhancing the thermal conductivity of YBCO superconducting material can be widely used in other DIW 3D-printing materials.
文摘In the current study poly(lactic acid)PLA composites with a 3 wt%and 5 wt%of nanofibrillated cellulose(NFC)were produced by 3D-printing method.An enzymatic pretreatment coupled with mechanical fibrillation in a twin screw extruder was used to produce high consistency NFC.Scanning electron microscopy(SEM)equipped with Fibermetric software,FASEP fiber length distribution analysis,Furrier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),tensile tests,impact tests and differential scanning calorimetry were used to characterize NFC and PLA/NFC composites.The results of the fiber length and width measurements together with the results of the SEM analysis showed that enzymatic hydrolysis coupled with a twin screw extrusion could effectively reduce the diameter and length of cellulose fibers.The produced NFC consisted of microand nanosized fibers entangled in a characteristic 3D-network.Based on the FT-IR analysis,no new bonds were formed during the enzymatic hydrolysis or fibrillation process.The TGA analysis confirmed that produced NFC can be used in hightemperature extrusion processing without NFC degradation.During the PLA/NFC composites preparation the NFC agglomerates were formed,which negatively influenced PLA/NFC composites impact properties.The slightly improved tensile strength and elastic modulus were reported for all composites when compared to the neat PLA.The elongation at break was not affected by the NFC addition.No significant differences in thermal stability were detectable among composites nor in comparation with the neat PLA.However,the crystallinity degree of the composite containing 5 wt%NFC was increased in respect to the neat PLA.
基金This study was supported by the Education Department of Hainan Province(HnjgY2022-12)Hainan Provincial Natural Science Foundation of China(320CXTD437 and 2019RC189)+1 种基金the National Natural Science Foundation of China(32260127 and 31672303)to CYthe Hainan Provincial Innovative Research Program for Graduates(Qhyb2021-55)to XC.
文摘Living and/or non-living animal models are often used as stimuli to observe the behavioral responses of the target animals.In the past,parasites,predators,and harmless controls have been used to test host anti-parasitism defense behavior,and their taxidermy specimens have been widely used as a set of standard methods for the study of avian brood parasitism.In recent years,with the rapid development of 3D-printing technology,3D-printed bird models are expected to be applied as a standard method in the study of avian brood parasitism.To evaluate the use of 3D-printed models,this study tests the reaction of Oriental Reed Warbler(Acrocephalus orientalis)towards predators,parasites,or controls,and compares the reaction among different nest intruders and between taxidermy specimens and 3D-printed animal models.It was found that the Oriental Reed Warbler responded most aggressively to the parasite,followed by predator,and finally the control;the results were consistent between the reaction to taxidermy specimens and 3D-printed animal models,indicating that 3D-printed models could serve as a substitute for taxidermy specimens.We propose a series of advantages of using 3D-printed models and suggest them to be a standard method for widespread use in future studies of avian brood parasitism.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51373048)the National Key Research and Development Program of China(Grant Nos.U1604253 and 2016YFB0101602)
文摘To improve the strength of carbon fiber(CF) reinforced Polycaprolactam(PA6) composites, controlled amounts of carbon nanotubes(CNTs) were grafted onto the surface of CF to prepare the hybrid reinforcement(HR). We used HR to fabricate laminate and H-sample to test the interfacial bonding strength(IBS) of the composites by means of a novel process called three-dimensional printed molding(3 D-PM). By using the melt drop printing method, we measured the contact angles between PA6 and CF(without sizing) and between PA6 and HR. The IBS and the mechanical properties of the composites were obtained by the tensile test. The experimental result indicated that CF grafted by 0.25% weight fraction of CNT or more could develop a special microstructure similar to the micro-pits on the surface of CF, which improved the wettability of CF and PA6 due to the increased surface area and the roughness of CF. When the weight fraction of CNT reached 0.25%, the IBS increased by 41.8%, the tensile strength by 130%, and the interfacial shear strength(IFSS) by 238%. The interfacial dimple fracture was observed by Scanning Electron Microscope(SEM), which revealed that the composites were able to absorb more deforming energy before fracture. The modified surface microstructure of CF would prevent crack propagation at the interface and increase the mechanical properties of thermoplastic composites(TPCs).
文摘Postoperative anatomical reconstruction and prevention of local recurrence after tumor resection are two vital clinical challenges in osteosarcoma treatment.A three-dimensional(3D)-printed porous Ti6Al4V scaffold(3DTi)is an ideal material for reconstructing critical bone defects with numerous advantages over traditional implants,including a lower elasticity modulus,stronger bone-implant interlock,and larger drug-loading space.Simvastatin is a multitarget drug with anti-tumor and osteogenic potential;however,its efficiency is unsatisfactory when delivered systematically.Here,simvastatin was loaded into a 3DTi using a thermosensitive poly(lactic-co-gly-colic)acid(PLGA)-polyethylene glycol(PEG)-PLGA hydrogel as a carrier to exert anti-osteosarcoma and oste-ogenic effects.Newly constructed simvastatin/hydrogel-loaded 3DTi(Sim-3DTi)was comprehensively appraised,and its newfound anti-osteosarcoma mechanism was explained.Specifically,in a bone defect model of rabbit condyles,Sim-3DTi exhibited enhanced osteogenesis,bone in-growth,and osseointegration compared with 3DTi alone,with greater bone morphogenetic protein 2 expression.In our nude mice model,simvastatin loading reduced tumor volume by 59%-77%without organic damage,implying good anti-osteosarcoma activity and biosafety.Furthermore,Sim-3DTi induced ferroptosis by upregulating transferrin and nicotinamide adenine dinucleotide phosphate oxidase 2 levels in osteosarcoma both in vivo and in vitro.Sim-3DTi is a promising osteogenic bone substitute for osteosarcoma-related bone defects,with a ferroptosis-mediated anti-osteosarcoma effect.
基金supported by the Guangdong Province Youth Innovative Talents Project in Higher Education (No.2018KQNCX257)the Guangdong Province Enterprise Science and Technology Commissioner Project (No.GDKTP2021048000)+4 种基金the Key-Area Research and Development Program of Guangdong Province (No.2020B090923002)the Guangdong-Dongguan Joint Fund (No.2019B151530005)the Guangdong Basic and Applied Basic Research Foundation (No.2019A1515110497)the National Natural Science Foundation of China (No.41907292)the National Natural Science Foundation of China (No.21876130)。
文摘Here,we report the production of 3D-printed MoS_(2)/Ni electrodes(3D-MoS_(2)/Ni)with longterm stability and excellent performance by the selective laser melting(SLM)technique.As a cathode,the obtained 3D-MoS_(2)/Ni could maintain a degradation rate above 94.0%for forfenicol(FLO)when repeatedly used 50 times in water.We also found that the removal rate of FLO by 3D-MoS_(2)/Ni was about 12 times higher than that of 3D-printed pure Ni(3D-Ni),attributed to the improved accessibility of H^(*).In addition,the electrochemical characterization results showed that the electrochemically active surface area of the 3D-MoS_(2)/Ni electrode is about 3-fold higher than that of the 3D-Ni electrode while the electrical resistance is 4 times lower.Based on tert-butanol suppression,electron paramagnetic resonance and triple quadrupole mass spectrometer experiments,a“dual path”mechanism and possible degradation pathway for the dechlorination of FLO by 3D-MoS_(2)/Ni were proposed.Furthermore,we also investigated the impacts of the cathode potential and the initial pH of the solution on the degradation of FLO.Overall,this study reveals that the SLM 3D printing technique is a promising approach for the rapid fabrication of high-stability metal electrodes,which could have broad application in the control of water contaminants in the environmental field.
基金supported by the National Natural Science Foundation of China(Grant No.82202690)the Shanghai Pujiang Program(2022PJD051)+1 种基金the China Postdoctoral Science Foundation(2022M712121)the Basic Science Program of Shanghai Sixth People’s Hospital(Grant No.ynqn202203).
文摘The integrative regeneration of both articular cartilage and subchondral bone remains an unmet clinical need due to the difficulties of mimicking spatial complexity in native osteochondral tissues for artificial implants.Layer-by-layer fabrication strategies,such as 3D printing,have emerged as a promising technology replicating the stratified zonal architecture and varying microstructures and mechanical properties.However,the dynamic and circulating physiological environments,such as mass transportation or cell migration,usually distort the pre-confined biological properties in the layered implants,leading to undistinguished spatial variations and subsequently inefficient regenerations.This study introduced a biomimetic calcified interfacial layer into the scaffold as a compact barrier between a cartilage layer and a subchondral bone layer to facilitate osteogenic-chondrogenic repair.The calcified interfacial layer consisting of compact polycaprolactone(PCL),nano-hydroxyapatite,and tasquinimod(TA)can physically and biologically separate the cartilage layer(TA-mixed,chondrocytes-load gelatin methacrylate)from the subchondral bond layer(porous PCL).This introduction preserved the as-designed independent biological environment in each layer for both cartilage and bone regeneration,successfully inhibiting vascular invasion into the cartilage layer and preventing hyaluronic cartilage calcification owing to devascularization of TA.The improved integrative regeneration of cartilage and subchondral bone was validated through gross examination,micro-computed tomography(micro-CT),and histological and immunohistochemical analyses based on an in vivo rat model.Moreover,gene and protein expression studies identified a key role of Caveolin(CAV-1)in promoting angiogenesis through the Wnt/β-catenin pathway and indicated that TA in the calcified layer blocked angiogenesis by inhibiting CAV-1.
基金the Natural Science Foundation of Zhejiang Province(Grant No.LR19E090001)the Natural Science Foundation of China(Grant Nos.42077252,42011530122,and 51979272).
文摘Nonlinear flow behavior of fluids through three-dimensional(3D)discrete fracture networks(DFNs)considering effects of fracture number,surface roughness and fracture aperture was experimentally and numerically investigated.Three physical models of DFNs were 3D-printed and then computed tomography(CT)-scanned to obtain the specific geometry of fractures.The validity of numerically simulating the fluid flow through DFNs was verified via comparison with flow tests on the 3D-printed models.A parametric study was then implemented to establish quantitative relations between the coefficients/parameters in Forchheimer’s law and geometrical parameters.The results showed that the 3D-printing technique can well reproduce the geometry of single fractures with less precision when preparing complex fracture networks,numerical modeling precision of which can be improved via CT-scanning as evidenced by the well fitted results between fluid flow tests and numerical simulations using CT-scanned digital models.Streamlines in DFNs become increasingly tortuous as the fracture number and roughness increase,resulting in stronger inertial effects and greater curvatures of hydraulic pressure-low rate relations,which can be well characterized by the Forchheimer’s law.The critical hydraulic gradient for the onset of nonlinear flow decreases with the increasing aperture,fracture number and roughness,following a power function.The increases in fracture aperture and number provide more paths for fluid flow,increasing both the viscous and inertial permeabilities.The value of the inertial permeability is approximately four orders of magnitude greater than the viscous permeability,following a power function with an exponent a of 3,and a proportional coefficient b mathematically correlated with the geometrical parameters.
基金National Key Research and Development Program of China(2018YFA0703000)National Natural Science Foundation of China(22072047,U1801252)Science and Technology Program of Guangzhou(202007020002).
文摘The classical 3D-printed scaffolds have attracted enormous interests in bone regeneration due to the customized structural and mechanical adaptability to bone defects.However,the pristine scaffolds still suffer from the absence of dynamic and bioactive microenvironment that is analogous to natural extracellular matrix(ECM)to regulate cell behaviour and promote tissue regeneration.To address this challenge,we develop a black phosphorus nanosheets-enabled dynamic DNA hydrogel to integrate with 3D-printed scaffold to build a bioactive gel-scaffold construct to achieve enhanced angiogenesis and bone regeneration.The black phosphorus nanosheets reinforce the mechanical strength of dynamic self-healable hydrogel and endow the gel-scaffold construct with preserved protein binding to achieve sustainable delivery of growth factor.We further explore the effects of this activated construct on both human umbilical vein endothelial cells(HUVECs)and mesenchymal stem cells(MSCs)as well as in a critical-sized rat cranial defect model.The results confirm that the gel-scaffold construct is able to promote the growth of mature blood vessels as well as induce osteogenesis to promote new bone formation,indicating that the strategy of nano-enabled dynamic hydrogel integrated with 3D-printed scaffold holds great promise for bone tissue engineering.
基金supported by Hong Kong Health Bureau (DFEK:Health Medical and Research Fund,08190466,DMW:Health Medical and Research Fund,07180686)Hong Kong Research Grants Council (DFEK:Early Career Scheme Award,24201720,General Research Fund:14213922,DMW:General Research Fund:14118620 and 14121121)+3 种基金National Natural Science Foundation of China-Hong Kong Research Grants Council Joint Research Scheme (DMW:N_CUHK409/23)Hong Kong Innovation and Technology Commission (DFEK:Tier 3 Award,ITS/090/18,DW:ITS/333/18DFEK,DMW,and RST:Health@InnoHK program)The Chinese University of Hong Kong (DFEK:Faculty Innovation Award,FIA2018/A/01)。
文摘Facile and rapid 3D fabrication of strong,bioactive materials can address challenges that impede repair of large-to-massive rotator cuff tears including personalized grafts,limited mechanical support,and inadequate tissue regeneration.Herein,we developed a facile and rapid methodology that generates visible light-crosslinkable polythiourethane(PHT)pre-polymer resin(~30 min at room temperature),yielding 3D-printable scaffolds with tendon-like mechanical attributes capable of delivering tenogenic bioactive factors.Ex vivo characterization confirmed successful fabrication,robust human supraspinatus tendon(SST)-like tensile properties(strength:23 MPa,modulus:459 MPa,at least 10,000 physiological loading cycles without failure),excellent suture retention(8.62-fold lower than acellular dermal matrix(ADM)-based clinical graft),slow degradation,and controlled release of fibroblast growth factor-2(FGF-2)and transforming growth factor-β3(TGF-β3).In vitro studies showed cytocompatibility and growth factor-mediated tenogenic-like differentiation of mesenchymal stem cells.In vivo studies demonstrated biocompatibility(3-week mouse subcutaneous implantation)and ability of growth factor-containing scaffolds to notably regenerate at least 1-cm of tendon with native-like biomechanical attributes as uninjured shoulder(8-week,large-to-massive 1-cm gap rabbit rotator cuff injury).This study demonstrates use of a 3D-printable,strong,and bioactive material to provide mechanical support and pro-regenerative cues for challenging injuries such as large-to-massive rotator cuff tears.
基金supported by the Priority Research Centers Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(Grant 2017R1A6A03015562 and RS-2023-00237386).
文摘Fucoidan,a sulfate polysaccharide obtained from brown seaweed,has various bioactive properties,including anti-inflammatory,anti-cancer,anti-viral,anti-oxidant,anti-coagulant,anti-thrombotic,anti-angiogenic,and anti-Helicobacter pylori properties.However,the effects of low-molecular-weight fucoidan(LMW-F)on melanoma cell lines and three dimensional(3D)cell culture models are not well understood.This study aimed to investigate the effects of LMW-F on A375 human melanoma cells and cryopreserved biospecimens derived from patients with advanced melanoma.Ultrasonic wave was used to fragment fucoidan derived from Fucus vesiculosus into smaller LMW-F.MTT and live/dead assays showed that LMW-F inhibited cell proliferation in both A375 cells and patientderived melanoma explants in a 3D-printed collagen scaffold.The PTEN/AKT pathway was found to be involved in the anti-melanoma effects of fucoidan.Western blot analysis revealed that LMW-F reduced the phosphorylation of Bcl-2 at Thr 56,which was associated with the prevention of anti-apoptotic activity of cancer cells.Our findings suggested that LMW-F could enhance anti-melanoma chemotherapy and improve the outcomes of patients with melanoma resistance.
基金supported by the National Institutes of Health grant R01 AR075037 and R01 AR56212.
文摘Three-dimensional (3D) printing technology is driving forward the progresses of various engineering fields, including tissue engineering. However, the pristine 3D-printed scaffolds usually lack robust functions in stimulating desired activity for varied regeneration applications. In this study, we combined the two-dimensional (2D) hetero-nanostructures and immuno-regulative interleukin-4 (IL-4) cytokines for the functionalization of 3D-printed scaffolds to achieve a pro-healing immuno-microenvironment for optimized bone injury repair. The 2D hetero-nanostructure consists of graphene oxide (GO) layers, for improved cell adhesion, and black phosphorous (BP) nanosheets, for the continuous release of phosphate ions to stimulate cell growth and osteogenesis. In addition, the 2D hetero-nanolayers facilitated the adsorption of large content of immuno-regulative IL-4 cytokines, which modulated the polarization of macrophages into M2 phenotype. After in vivo implantation in rat, the immuno-functioned 3D-scaffolds achieved in vivo osteo-immunomodulation by building a pro-healing immunological microenvironment for better angiogenesis and osteogenesis in the defect area and thus facilitated bone regeneration. These results demonstrated that the immuno-functionalization of 3D-scaffolds with 2D hetero-nanostructures with secondary loading of immuno-regulative cytokines is an encouraging strategy for improving bone regeneration.
基金This work was sponsored by the National Science Foundation of China(Nos.32071341,52202358,52003302)The Natural Science Foundation of Guangdong Province(No.2017A030308004)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110824)the Science and Technology Project of Guangdong province(No.2018A050506021).
文摘The architecture and surface modifications have been regarded as effective methods to enhance the bi-ological response of biomaterials in bone tissue engineering.The porous architecture of the implanta-tion was essential conditions for bone regeneration.Meanwhile,the design of biomimetic hydroxyap-atite(HAp)coating on porous scaffolds was demonstrated to strengthen the bioactivity and stimulate osteogenesis.However,bioactive bio-ceramics such asβ-tricalcium phosphate(β-TCP)and calcium sili-cate(CS)with superior apatite-forming ability were reported to present better osteogenic activity than that of HAp.Hence in this study,3D-printed interconnected porous bioactive ceramicsβ-TCP/CS scaf-fold was fabricated and the biomimetic HAp apatite coating were constructed in situ via hydrothermal reaction,and the effects of HAp apatite layer on the fate of mouse bone mesenchymal stem cells(mBM-SCs)and the potential mechanisms were explored.The results indicated that HAp apatite coating en-hanced cell proliferation,alkaline phosphatase(ALP)activity,and osteogenic gene expression.Further-more,PI3K/AKT/mTOR signaling pathway is proved to have an important impact on cellular functions.The present results demonstrated that the key molecules of phosphatidylinositol 3-kinase(PI3K),protein kinase B(AKT)and mammalian target of rapamycin(mTOR)were activated after the biomimetic hydrox-yapatite coating were constructed on the 3D-printed ceramic scaffolds.Besides,the activated influence on the protein expression of Runx2 and BMP2 could be suppressed after the treatment of inhibitor HY-10358.In vivo studies showed that the constructed HAp coating promoted bone formation and strengthen the bone quality.These results suggest that biomimetic HAp coating constructed on the 3D-printed bioac-tive composite scaffolds could strengthen the bioactivity and the obtained biomimetic multi-structured scaffolds might be a potential alternative bone graft for bone regeneration.
基金supported by National Natural Science Foundation of China(32271386,31900945)Zhejiang Traditional Chinese Medicine Scientific Research Fund Project(2022ZB342)+3 种基金Chengdu Municipal Technological Innovation R&D Project(2021-YF05-01871-SN)Project of Chengdu Municipal Health Commission(2021059)the seed grants from the Wenzhou Institute,University of Chinese Academy of Sciences(WIUCASQD2020013,WIUCASQD2021030)the funding from First Affiliated Hospital of Wenzhou Medical University.
文摘The increased number of mastectomies,combined with rising patient expectations for cosmetic and psychosocial outcomes,has necessitated the use of adipose tissue restoration techniques.However,the therapeutic effect of current clinical strategies is not satisfying due to the high demand of personalized customization and the timely vascularization in the process of adipose regeneration.Here,a composite hydrogel scaffold was prepared by three-dimensional(3D)printing technology,applying gelatin methacrylate anhydride(GelMA)as printing ink and calcium silicate(CS)bioceramic as an active ingredient for breast adipose tissue regeneration.The in vitro experiments showed that the composite hydrogel scaffolds could not only be customized with controllable architectures,but also significantly stimulated both 3T3-L1 preadipocytes and human umbilical vein endothelial cells in multiple cell behaviors,including cell adhesion,proliferation,migration and differentiation.Moreover,the composite scaffold promoted vascularized adipose tissue restoration under the skin of nude mice in vivo.These findings suggest that 3D-printed GelMA/CS composite scaffolds might be a good candidate for adipose tissue engineering.
基金supported by the National Natural Science Foundation of China(No.52072248)Natural Science Foundation of Guangdong Province of China(No.2021A1515012128,No.2018A030313574)+1 种基金Natural Science Foundation of SZU(No.827-000357)Science and Technology Plan of Shenzhen City(Grant No.JCYJ20190813171603633).
文摘Bi_(2)Te_(3)-based materials were prepared by direct ink writing(DIW)3D printing and their microstructure and thermoelectric properties were investigated with an emphasis on the effect of the content of DMF and Te/Se addition.As the mass ratio of DMF in the composition increased from 6.5%to 8.0%(in mass),the electrical conductivity deteriorated because of the corresponding increased porosity and organic remains in the samples.However,the volatilization of DMF would reduce the fluidity of the slurry.Thus,thermoelectric slurry with 7.0%DMF is the most suitable mass ratio for 3D printing.Additionally,adding Te in the p-type Bi0.4Sb1.6Te3 and adding Se in the n-type Bi2Te2.6Se0.4 have significantly improved their electrical conductivity due to the increased carrier concentration and mobility.Combining with the moderate Seebeck coefficient(~200 mV/K),high power factors with~802 mW·m^(-1)·K^(-2)and 1266 mW·m^(-1)·K^(-2)were obtained for the n-type Bi_(2)Te_(2.6)Se_(0.4)þ10%Se and p-type Bi_(0.4)Sb_(1.6)Te_(3)þ7%Te,respectively,which result in the final relatively high zT values of 0.68 at 573 K and 0.56 at 330 K for ntype and p-type 3D-printed samples.
文摘Highly deformable bodies are essential for numerous types of applications in all sorts of environments. Joint-like structures comprising a ball and socket joint have many degrees of freedom that allow mobility of many biomimetic structures. Recently, soft robots are favored over rigid structures for their highly compliant material, high-deformation properties at low forces, and ability to operate in di fficult environments. However, it is still challenging to fabricate complex designs that satisfy application constraints due to the combined e ffects of material properties, actuation method, and structural geometry on the performance of the soft robot. Therefore, a combination of a rigid joint and a soft body can help achieve modular robots with fully functional body morphology. Yet, the fabrication of soft parts requires extensive molding for complex shapes, which comprises several processes and can be time-consuming. In addition, molded connections between extremely soft materials and hard materials can be critical failing points. In this paper, we present a functionally graded 3D-printed joint-like structure actuated by novel contractile actuators. Functionally graded materials (FGMs) via 3D printing allow for extensive material property enhancement and control which warrant tunable functionalities of the system. The 3D-printed structure is made of 3 rigid ball and socket joints connected in series and actuated by integrating twisted and coiled polymer fishing line ( TCPFL) actuators, which are con fined in the FGM accordion-shaped channels. The implementation of the untethered T CPFL actuation system can be highly bene ficial for deployment in environments that require low vibrations and silent actuation. The fishing line TCP actuators produce an actuation strain up to 40% and bend the joint up to 40° in any direction. The T CPFL can be actuated individually or as a group to control the bending trajectory of the modular joint, which is bene ficial when deployed in areas that contain small crevices. Obtaining complex modes of bending, the FGM multidirectional joint demonstrated a great potential to achieve di fferent functionalities such as crawling, rolling, swimming, or underwater exploration.
基金Supported by the Shanxi Provincial Key Research and Development Program,No.201903D321175.
文摘BACKGROUND Hernia is a common condition requiring abdominal surgery.The current standard treatment for hernia is tension-free repair using meshes.Globally,more than 200 new types of meshes are licensed each year.However,their clinical applications are associated with a series of complications,such as recurrence(10%-24%)and infection(0.5%-9.0%).In contrast,3D-printed meshes have significantly reduced the postoperative complications in patients.They have also shortened operating time and minimized the loss of mesh materials.In this study,we used the myopectineal orifice(MPO)data obtained from preoperative computer tomography(CT)-based 3D reconstruction for the production of 3D-printed biologic meshes.AIM To investigate the application of multislice spiral CT-based 3D reconstruction technique in 3D-printed biologic mesh for hernia repair surgery.METHODS We retrospectively analyzed 60 patients who underwent laparoscopic tension-free repair for inguinal hernia in the Department of General Surgery of the First Hospital of Shanxi Medical University from September 2019 to December 2019.This study included 30 males and 30 females,with a mean age of 40±5.6 years.Data on the MPO were obtained from preoperative CT-based 3D reconstruction as well as from real-world intraoperative measurements for all patients.Anatomic points were set for the purpose of measurement based on the definition of MPO:A:The pubic tubercle;B:Intersection of the horizontal line extending from the summit of the inferior edge of the internal oblique and transversus abdominis and the outer edge of the rectus abdominis,C:Intersection of the horizontal line extending from the summit of the inferior edge of the internal oblique and transversus abdominis and the inguinal ligament,D:Intersection of the iliopsoas muscle and the inguinal ligament,and E:Intersection of the iliopsoas muscle and the superior pubic ramus.The distance between the points was measured.All preoperative and intraoperative data were analyzed using the t test.Differences with P<0.05 were considered significant in comparative analysis.RESULTS The distance between points AB,AC,BC,DE,and AE based on preoperative and intraoperative data was 7.576±0.212 cm vs 7.573±0.266 cm,7.627±0.212 cm vs 7.627±0.212 cm,7.677±0.229 cm vs 7.567±0.786 cm,7.589±0.204 cm vs 7.512±0.21 cm,and 7.617±0.231 cm vs 7.582±0.189 cm,respectively.All differences were not statistically significant(P>0.05).CONCLUSION The use of multislice spiral CT-based 3D reconstruction technique before hernia repair surgery allows accurate measurement of data and relationships of different anatomic sites in the MPO region.This technique can provide precise data for the production of 3D-printed biologic meshes.
文摘A study was conducted to evaluate the current production capabilities of the Mark One? 3D printer in printing carbon fibre reinforced thermoplastic (CFRTP) tensile test specimens according to the JIS K 7073 by making use of fused deposition modelling. Several different types of CFRTP tensile test specimens are printed and are tensile tested in the longitudinal direction to obtain an overview of the mechanical properties of 3D printed CFRTP material. These properties are compared with the literature values known for composite materials to see if these agree. The main goal of this research is to increase the knowledge of the 3D printing process of CFRTP and to later use this knowledge to further improve the 3D printing process to obtain stronger 3D printed CFRTP materials.
