3D-printed Ti6Al4V Research Articles

A novel hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold with enhanced osteoporotic osseointegration through osteoimmunomodulation

BackgroundFemoral stem of titanium alloy has been widely used for hip arthroplasty with considerable efficacy; however, the application of this implant in patients with osteoporosis is limited due to excessive bone resorption. Macrophages participate in the regulation of inflammatory response and have been a topic of increasing research interest in implant field. However, few study has explored the link between macrophage polarization and osteogenic–osteoclastic differentiation. The present study aims to develop a novel hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold with enhanced osteoporotic osseointegration through immunotherapy.MethodTo improve the osteointegration under osteoporosis, we developed a hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold (PT). Biomimetic extracellular matrix (ECM) was constructed inside the interconnected pores of PT in micro-scale. And in nano-scale, a drug cargo icariin@Mg-MOF-74 (ICA@MOF) was wrapped in ECM-like structure that can control release of icariin and Mg2+.ResultsIn this novel hierarchical biofunctionalized 3D-printed porous Ti6Al4V scaffold, the macroporous structure provides mechanical support, the microporous structure facilitates cell adhesion and enhances biocompatibility, and the nanostructure plays a biological effect. We also demonstrate the formation of abundant new bone at peripheral and internal sites after intramedullary implantation of the biofunctionalized PT into the distal femur in osteoporotic rats. We further find that the controlled-release of icariin and Mg2+ from the biofunctionalized PT can significantly improve the polarization of M0 macrophages to M2-type by inhibiting notch1 signaling pathway and induce the secretion of anti-inflammatory cytokines; thus, it significantly ameliorates bone metabolism, which contributes to improving the osseointegration between the PT and osteoporotic bone.ConclusionThe therapeutic potential of hierarchical PT implants containing controlled release system are effective in geriatric orthopaedic osseointegration.Graphical

3D-printed porous Ti6Al4V alloys with silver coating combine osteocompatibility and antimicrobial properties

Additive manufacturing allows for the production of porous metallic implants for use in orthopaedics, providing excellent mechanical stability and osseointegration. However, the increased surface area of such porous implants also renders them susceptible to bacterial colonization. In this work, two trabecular porous Ti6Al4V alloys produced by electron beam melting were investigated for their osteocompatibility and antimicrobial effects, comparing samples with a silver-coated surface to uncoated samples. Dense grit-blasted Ti samples were used for comparison. The porous samples had pore sizes of 500–600 μm and 5 to 10 μm surface roughness, the silver-coated samples contained 7 at.% Ag, resulting in a cumulative Ag release of 3.5 ppm up to 28 days. Silver reduced the adhesion of Staphylococcus aureus to porous samples and inhibited 72 h biofilm formation by Staphylococcus epidermidis but not that of S. aureus. Primary human osteoblast adhesion, proliferation and differentiation were not impaired in the presence of silver, and expression of osteogenic genes as well as production of mineralized matrix were similar on silver-coated and uncoated samples. Our findings indicate that silver coating of porous titanium implants can achieve antimicrobial effects without compromising osteocompatibility, but higher silver contents may be needed to yield a sustained protection against fast-growing bacteria.

Enhanced osseointegration of 3D-printed cementless tibial prostheses with trabecular metal surfaces in a novel three-partition design

Compared with cemented implants in total knee arthroplasty (TKA), cementless prostheses can provide better biological fixation for young and active patients by their osseointegration with host bone. However, to date, early loosening occurs in most cementless knee prostheses due to extensive bone ingrowth deficiencies, especially at the tibial bone-prosthesis interfaces. This study aims to improve the osseointegration capability of 3D-printed cementless tibial prostheses by modifying metal surfaces with a three-partition trabecular-like porous structure. Ti6Al4V tibial prostheses were prepared with a novel three-partition trabecular surface design by electron beam melting (EBM) according to the regional structural and mechanical properties of human tibial plateaus. The trabecular prostheses were implanted in the knee joints of sheep in situ to evaluate the osseointegration and stability of the designed tibial implants. X-ray images and anatomical observation showed no detachment or displacement of the trabecular implants at 3 and 6 months postoperation. Micro-CT evaluation and histological analysis showed improved osseointegration and strengthened biological fixation of the trabecular implants. The cellular experiment results indicated that three topological types of porous scaffolds corresponding to the three-partition trabecular prosthesis design were favorable for the proliferation and differentiation of preosteoblasts. In conclusion, a novel three-partition trabecular surface design enhanced the osseointegration capacity of 3D-printed Ti6Al4V tibial implants, which will promote the application of cementless knee prostheses in clinics.

Solid solubility and charge compensation/exchange mechanisms in Ga- or Mn-Doped CeO2 thin films on 3D printed biomedical titanium alloy

CeO2 films doped with 0–9 mol% Ga/Mn were fabricated by spin coating on 3D-printed Ti6Al4V, calcined at 650 °C for 2 h, and characterised by TEM, FESEM, 3D laser scanning confocal microscopy, GAXRD, and XPS. The results depend on the roles of several factors: (1) Sol-gel precursor viscosity affected pore filling and surface coverage. (2) Lattice contraction and resultant intervalence charge transfer increased the Ce3+ concentration as a minority effect. (3) Substitutional solid solubility and associated redox charge compensation controlled the defect equilibria, which highlight the majority role of this solid solubility mechanism in decreasing the Ce3+ concentration. (4) Electronegativity played a negligible role in affecting the valences but was important in initiating intervalence charge transfer. (5) Multivalence charge transfer combined electron exchanges between film matrix, dopants, and Ti substrate. The present work provides a foundation to interpret the effects of extrinsic effects from both dopant and substrate on the properties of films.

Incorporation of Bone Morphogenetic Protein-2 and Osteoprotegerin in 3D-Printed Ti6Al4V Scaffolds Enhances Osseointegration Under Osteoporotic Conditions.

Osteoporosis is an age-related metabolic disease that results in limited bone regeneration capacity and excessive osteoclast activity. After arthroplasty in patients with osteoporosis, poor interface osseointegration resulting from insufficient bone regeneration ability often leads to catastrophic complications such as prosthesis displacement and loosening and periprosthetic fractures. In this study, we prepared a thermosensitive hydrogel loaded with bone morphogenetic protein-2 (BMP-2) to promote osteogenesis and osteoprotegerin (OPG) to inhibit excessive osteoclast activity. To construct three-dimensional (3D)-printed composite scaffolds for implantation, a hydrogel loaded with drugs was injected into porous Ti6Al4V scaffolds. The 3D-printed composite scaffolds showed good biocompatibility and sustained release of BMP-2 and OPG for more than 20 days. In vitro experiments indicated that composite scaffolds promoted osteogenic differentiation and reduced the osteoclastic activation simultaneously. Remarkably, immunofluorescence staining, micro-CT, histological, and biomechanical tests demonstrated that the sustained release of both BMP-2 and OPG from composite scaffolds significantly improved bone ingrowth and osseointegration in osteoporotic defects. In conclusion, this study demonstrated that the BMP-2- and OPG-loaded 3D-printed composite scaffolds can potentially promote osseointegration for osteoporotic patients after joint replacement.

3D-printed Ti6Al4V femoral component of knee: Improvements in wear and biological properties by AIP TiN and TiCrN coating

As patients are dissatisfied with the excessive weight of Co-based knee femoral components, it is an urgent need to reduce their weight without compromising the excellent mechanical properties. In the present study, femoral components of knee with Ti6Al4V alloy (86 g) or Co–Cr alloy (192 g) were printed by selective laser melting (SLM). In order to improve the mechanical properties and biocompatibility of 3D-printed Ti6Al4V, TiN and TiCrN coating layers were deposited on the surface of SLM Ti6Al4V using arc ion plating (AIP) system. The surface characterizations were analyzed by scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), X-ray diffraction (XRD), contact angle tensiometer, and contact profilometer. The wear property, hardness value and corrosion resistance in phosphate buffered saline (PBS) were also investigated through vickers hardness, sliding wear test, electrochemical impedance spectroscopy and potentiodynamic polarization. The antibacterial capability and biocompatibility were assessed with Staphylococcus aureus and mesenchymal stem cells (MSCs) in vitro . Results illustrated that, after coating SLM Ti6Al4V with thin TiN and TiCrN layers, the hardness, anti-wear performance and corrosion resistance of SLM Ti6Al4V were significantly improved and became comparable to SLM CoCr. The TiN and TiCrN coated SLM Ti6Al4V also showed moderate antibacterial ability, and excellent biocompatibility in comparation with SLM Ti6Al4V and SLM CoCr.

Research on the Dynamic Compressive Deformation Behavior of 3D-Printed Ti6Al4V

In this paper, the plastic flow and fracture behavior of 3D-printed Ti6Al4V (TC-4) alloy under different temperatures (289–1073 K) and strain rates (0.1–4100 s−1) were studied by using the MTS comprehensive experimental machine (MTS) and split Hopkinson pressure bar (SHPB) equipment. The patterns of the influence of temperature and strain rate on the plastic flow behavior of 3D-printed materials in different printing directions were analyzed and compared with those of the traditional TC-4. Based on the experimental data, the modified Johnson–Cook (J-C) constitutive model of 3D-printed TC-4 alloy was established, and the plastic deformation behavior of the material driven by detonation was studied by X-ray photography. The research results showed that under static loading conditions, the strength of the material (AM-P-TC-4) along the printing direction was much higher than the strength of the material perpendicular to the printing direction (AM-T-TC-4). However, there was no difference in material strength for different directions under dynamic loading. Second, under the same deformation conditions, the strength of the 3D-printed TC-4 alloy was considerably higher than that of the traditional TC-4 alloy, but adiabatic shear fracture could be more easily induced under dynamic compressive deformation conditions for the 3D-printed TC-4 alloy, and its fracture strain was substantially less than that of TC-4 alloys. The modified J-C constitutive model established in this paper could better describe the plastic flow behavior of the AM-P-TC-4 alloy under high temperature and high-strain rate deformation conditions.

Biotribocorrosion of 3D-Printed silica-coated Ti6Al4V for load-bearing implants.

Laser-based 3D Printing was utilized to deposit a silica (SiO2) coating on the surface of Ti6Al4V (Ti64) alloy for implementation onto articulating surfaces of load-bearing implants. The surface laser melting (SLM) technique was implemented in 1, and 2 laser passes (1LP and 2LP) after SiO2 deposition to understand the influence of remelting on the coating's hardness and tribological performance. It was observed that compositional and microstructural features increased the cross-sectional hardness. Wear rate was observed to decrease from 2.9×10-4 in the Ti64 to 5.2 ×10-6, 3.8×10-6, and 2.1×10-7 mm3/Nm for the as-processed or zero laser-pass (0LP), 1LP, and 2LP, respectively. Coated samples displayed a positive shift in open-circuit potential (OCP) during linear wear by displaying a 368, 85, and 613 mV increase compared to Ti64 for 0LP, 1LP, and 2LP, respectively. Our results showed promising tribological performance of SiO2 coated Ti6Al4V for articulating surfaces of load-bearing implants.

Effect of Surface Electropulsing Assisted Ultrasonic Impact Treatment on the Microstructure, Phase Composition, and Microhardness of 3D Printed Ti–6Al–4V Alloy

Effect of Surface Electropulsing Assisted Ultrasonic Impact Treatment on the Microstructure, Phase Composition, and Microhardness of 3D Printed Ti–6Al–4V Alloy

Surface treatment of 3D printed porous Ti6Al4V implants by ultraviolet photofunctionalization for improved osseointegration

Three-dimensional (3D)-printed porous Ti6Al4V implants play an important role in the reconstruction of bone defects. However, its osseointegration capacity needs to be further improved, and related methods are inadequate, especially lacking customized surface treatment technology. Consequently, we aimed to design an omnidirectional radiator based on ultraviolet (UV) photofunctionalization for the surface treatment of 3D-printed porous Ti6Al4V implants, and studied its osseointegration promotion effects in vitro and in vivo, while elucidating related mechanisms. Following UV treatment, the porous Ti6Al4V scaffolds exhibited significantly improved hydrophilicity, cytocompatibility, and alkaline phosphatase activity, while preserving their original mechanical properties. The increased osteointegration strength was further proven using a rabbit condyle defect model in vivo, in which UV treatment exhibited a high efficiency in the osteointegration enhancement of porous Ti6Al4V scaffolds by increasing bone ingrowth (BI), the bone-implant contact ratio (BICR), and the mineralized/osteoid bone ratio. The advantages of UV treatment for 3D-printed porous Ti6Al4V implants using the omnidirectional radiator in the study were as follows: 1) it can significantly improve the osseointegration capacity of porous titanium implants despite the blocking out of UV rays by the porous structure; 2) it can evenly treat the surface of porous implants while preserving their original topography or other morphological features; and 3) it is an easy-to-operate low-cost process, making it worthy of wide clinical application.

Practical strategy to construct anti-osteosarcoma bone substitutes by loading cisplatin into 3D-printed titanium alloy implants using a thermosensitive hydrogel

Surgical resection and perioperative adjuvant chemotherapy-based therapies have improved the prognosis of patients with osteosarcoma; however, intraoperative bone defects, local tumour recurrence, and chemotherapy-induced adverse effects still affect the quality of life of patients. Emerging 3D-printed titanium alloy (Ti6Al4V) implants have advantages over traditional implants in bone repair, including lower elastic modulus, lower stiffness, better bone conduction, more bone in-growth, stronger mechanical interlocking, and lager drug-loading capacity by their inherent porous structure. Here, cisplatin, a clinical first-line anti-osteosarcoma drug, was loaded into Ti6Al4V implants, within a PLGA-PEG-PLGA thermo-sensitive hydrogel, to construct bone substitutes with both anti-osteosarcoma and bone-repair functions. The optimal concentrations of cisplatin (0.8 and 1.6 mg/mL) were first determined in vitro. Thereafter, the anti-tumour effect and biosafety of the cisplatin/hydrogel-loaded implants, as well as their bone-repair potential were evaluated in vivo in tumour-bearing mouse, and bone defect rabbit models, respectively. The loading of cisplatin reduced tumour volume by more than two-thirds (from 641.1 to 201.4 mm3) with negligible organ damage, achieving better anti-tumour effects while avoiding the adverse effects of systemic cisplatin delivery. Although bone repair was hindered by cisplatin loading at 4 weeks, no difference was observed at 8 weeks in the context of implants with versus without cisplatin, indicating acceptable long-term stability of all implants (with 8.48%–10.04% bone in-growth and 16.94%–20.53% osseointegration). Overall, cisplatin/hydrogel-loaded 3D-printed Ti6Al4V implants are safe and effective for treating osteosarcoma-caused bone defects, and should be considered for clinical use.

Use of a novel Screen-Enrich-Combine(-biomaterials) Circulating System to fill a 3D-printed open Ti6Al4V frame with mesenchymal stem cells/β-tricalcium phosphate to repair complex anatomical bone defects in load-bearing areas.

BackgroundRepairing complex anatomical load-bearing bone defects is difficult because it requires the restoration of the load-bearing function, reconstructing the anatomical shape, and repair by regenerated bone. We previously developed a Screen–Enrich–Combine(-biomaterials) Circulating System (SECCS) for rapid intraoperative enrichment of autologous bone marrow mesenchymal stem cells (MSCs) to enhance the osteogenic ability of porous bone substitutes. In this study, we prepared a 3D-printed Ti6A14V macroporous frame matching the defect shape to provide early load-bearing support and evaluated the efficacy of filling the frame with SECCS-processed MSCs/beta tricalcium phosphate (β-TCP) for long-term bone growth.MethodsFifteen 2-year-old goats were involved in this study, and the lateral part of their distal femur was removed by an electric saw and was fitted by a matching electron beam melting technology-prepared (EBM) Ti6Al4V frame. Three types of frames, filled with nothing, pure porous β-TCP, or SECCS-processed MSCs/β-TCP, were fixed onto the defect site. Repair efficacy was evaluated by X-ray radiography, computed tomography (CT), histology, and histomorphometry.ResultsIn the basic regular hexagon printing unit, the combined side width (w) and the inscribed circle diameter (d) determines the printing frame’s mechanical strength. The compressive load was significantly higher for w=1.9 mm, d=4.4 mm than for w=1.7 mm, d=4.0 mm or w=2.0 mm, d=5.0 mm (P<0.05). The EBM-prepared Ti6Al4V defect-matched frame was well maintained 9 months after implantation. The MSCs successfully adhered to the wall of the porous β-TCP in the SECCS-processed group and had spread fully in the test samples. Each goat in the MSCs/β-TCP–the filled group, had approximately 31,321.7±22,554.7 of MSCs and a larger area of new bone growth inside the frame than the control and blank areas groups.ConclusionsFilling the 3D-printed Ti6Al4V large-aperture frame with osteogenic materials achieved biological reconstruction over a larger area of regenerated bone to repair complex anatomical weight-bearing bone defects under the condition of early frame-supported load bearing. MSCs/β-TCP prepared by SECCS can be used as a filling material for this type of bone defect to obtain more efficacious bone repair.

3D-Printed Ti6Al4V Scaffolds with Graded Triply Periodic Minimal Surface Structure for Bone Tissue Engineering

The repair of bone defect needs bionic scaffolds that meet biomechanical and bio-structural requirements. The triply periodic minimal surface (TPMS) scaffold, with a radial gradient porosity distribution mimicking natural bone, is a potential high-performance biomaterial for orthopedic implants. In this paper, TPMS scaffolds with various radial gradient porosities, which resembled the graded structure of human bone, were prepared by selective laser melting (SLM) with Ti6Al4V as a building material. The microstructure characteristics, mechanical properties and cell behaviors of scaffolds were systematically analyzed. Metallographic structure results showed that the grain size exhibited a radial decreasing porosity from the outer layer to the inner layer. The average porosity of all as-built samples ranged from 55% to 71%, and the average pore sizes ranged from 333μm to 674μm. The compression tests showed that the Young’s modulus (2.7-7.4GPa) and yield strength (233-520MPa) of all samples were sufficient to satisfy the requirements of human nature bone. Additionally, the cell viability of scaffolds by measuring the cell distribution and proliferation after 48h, 72h and 96h showed expected biocompatibility. The significance of this work is to improve the understanding of the effect of design parameters on the mechanical properties and cell growth of the scaffolds.

3D Printed Ti-6Al-4V Implant with a Micro/Nanostructured Surface and Its Cellular Responses.

Three-dimensional (3D) printing technology has been proved to be a powerful tool for the free-form fabrication of titanium (Ti) implants. However, the surface quality of 3D printed Ti implants is not suitable for clinical application directly. Therefore, surface modification of 3D printed Ti implants is required in order to achieve good biocompatibility and osseointegration. In this study, a novel surface modification method of 3D printed Ti–6Al–4V implants has been proposed, which combined acid etching with hydrothermal treatment to construct micro/nanostructures. Polished TC4 sheets (P), electron beam melting Ti sheets (AE), and micro/nanostructured Ti sheets (AMH) were used in this study to evaluate the effects of different surface morphologies on cellular responses. The surface morphology and 3D topography after treatment were detected via scanning electron microscopy and laser scanning microscopy. The results illustrated that a hierarchical structure comprising micro-valleys and nanowires with a surface roughness of 14.388 μm was successfully constructed. Compared with group P samples, the hydrophilicity of group AMH samples significantly increased with a reduced water contact angle from 54.9° to 4.5°. Cell culture experiments indicated that the micro/nanostructures on the material surface could enhance the cell adhesion and proliferation of MC3T3s. The microstructure could enhance bone-to-implant contact, and the nanostructure could directly interact with some cell membrane receptors. Overall, this study proposes a new strategy to construct micro/nanostructures on the surface of 3D printed Ti–6Al–4V implants and may further serve as a potential modification method for better osteogenesis ability.

Laser processing of freeform surfaces: A new approach based on an efficient workpiece partitioning strategy

A novel method for laser processing freeform surfaces is proposed and demonstrated in this article. The method employs empirical data on the 3D limitations of a given laser process, namely the negative effects of focal offset and angle of incidence on the process performance, to partition a freeform surface into triangular laser processing fields. In this way, processing efficiency can be maximized by minimizing part repositioning while fully utilizing the capabilities of high dynamics galvo scanners. In this proof of concept, the surface of 3D printed Ti–6Al–4V spherical shells was improved by more than 90% and subsequently textured, using the proposed method. Conclusions were made about the advantages of this new approach for processing freeform surfaces consistently and efficiently.

Free boundary effects and representative volume elements in 3D printed Ti–6Al–4V gyroid structures

Abstract

3D-printed Ti6Al4V scaffolds coated with freeze-dried platelet-rich plasma as bioactive interface for enhancing osseointegration in osteoporosis

The serious complications after arthroplasty in patients with osteoporosis is a challenge for orthopedics. Three-dimensional (3D)-printed porous titanium (pTi) alloys have the character of low stiffness, similar to cortical bone, and are seemed as promising materials in orthopedic applications, but limited by the bio-inert of titanium alloy. Thus, improving the bioactivity of the prosthesis and bone regeneration around the implant are crucial for the osseointegration. Herein, we established rabbit model of osteoporosis by bilateral ovariectomy, and the bioactive interface was constructed by coating 3D-printed pTi scaffolds with autologous platelet-rich plasma (PRP) prepared by traditional and Freeze-Dried methods. The pTi have advantages of ideal pore size, porosity and mechanical properties matching with bone tissue. In vitro, PRP-coated pTi significantly promoted bone marrow mesenchymal stem cells (BMSCs) attachment, proliferation, migration, and osteogenic differentiation. In vivo studies of the implant coatings were performed using osteoporosis models. The results indicated that this PRP-coated bioactive interface enhanced bone regeneration and osseointegration. Besides, compared with Traditional PRP, the Freeze-Dried PRP-coated pTi exhibited the superiority of promoting cell activity and osteogenic differentiation of BMSCs, and better bone formation. The novel Freeze-Dried PRP-coated pTi shows potential for the development of artificial prosthesis with bioactive interface for patients with osteoporosis.

Preparation and surface modification of 3D printed Ti–6Al–4V porous implant

Three-dimensional (3D) printed titanium alloy implants hold enormous potential in orthopedic applications to avoid stress shielding. However, titanium alloy is bioinert, limiting its application and making surface modification a necessity. In this paper, porous implants were treated by acid etching and anodizing to improve the bioactivity, which was evaluated by simulated body fluid (SBF) immersion test. The results showed that, after surface modification, micro–nanocomposite structures were obtained on the titanium surface, and after immersing in SBF for 2 weeks, the implants showed a drastically enhanced apatite forming ability, confirming improved bioactivity. However, the surface structures were different at different positions and it is believed that this phenomenon is closely related to the different current densities of the surfaces during anodic oxidation. Our research evaluates the effect of anodic oxidation at different voltages on the surface modification and provides a reference for improving the bioactivity of the medical porous implant surface prepared by 3D printing.

The synergistic effect of 3D-printed microscale roughness surface and nanoscale feature on enhancing osteogenic differentiation and rapid osseointegration

Personalized precision therapy and rapid osseointegration are the main development directions of dental implants. 3D printing is a vital advanced manufacturing technology for personalized precision therapy. However, the osteogenesis of the 3D printed Ti6Al4V implants is unsatisfactory. From the bionic perspective, the hierarchical micro/nano-topography can mimic the microenvironment of the multilevel structure of natural bone tissue and may endow the implant surface with superior bioactivity. In the present study, the hierarchical micro/nano-topography was successfully fabricated by construction the nanoscale feature on 3D printed microscale roughness surface of 3D-printed Ti6Al4V implants by alkali-heat treatment and hydrothermal treatment. Then the cell biological responses in vitro and osseointegration performance in vivo were systematically evaluated. The hierarchical micro/nano-topography evidently increased the roughness, improved the hydrophilicity and accelerated the hydroxyapatite deposition and mineralization, which significantly enhanced the adhesion, differentiation and extracellular matrix mineralization of bone marrow derived mesenchymal stromal cells (BMSCs). Most importantly, the hierarchical micro/nano-topography on 3D-printed implants facilitated the new bone formation and rapid osseointegration in vivo. Our study suggested that 3D-printed implant with micro/nano-topography may be a promising candidate to be applied in orthopedic field to meet the need of customized therapy and rapid osseointegration.

Microstructure and cyclic deformation behavior of a 3D-printed Ti–6Al–4V alloy

The main purpose of this investigation was to identify microstructure and cyclic deformation behavior of a 3D-printed Ti–6Al–4V alloy via selective electron beam melting (SEBM). Abundant orientated α-lamellae were present in the prior columnar β grains along the building direction. Four distinct high-angle α/α grain boundaries were detected as stipulated by the Burgers orientation relationship in the β→α phase transformation at a relatively slow cooling rate during SEBM, including the unique low-energy prismatic/basal (PB) grain boundaries with a misorientation angle of 90° in the 3D-printed Ti–6Al–4V alloy. The alloy exhibited superior strength and adequate ductility, along with a certain extent of strain-rate sensitivity. Cyclic stabilization largely sustained, while cyclic softening occurred at higher strain amplitudes. Although fatigue life could be described by Smith, Watson and Topper (SWT) model, it would be better predicted via a total strain energy-based model. Crack initiation occurred from near-surface defects of entrapped gas pores or residual unmelted zones, and crack propagation was characterized by typical fatigue striations. The results obtained would help promote the safe and reliable applications of 3D-printed titanium components.