3D-printed Constructs Research Articles

A review of molybdenum disulfide-based 3D printed structures for biomedical applications

MoS2 is a substance, highly valued for its two-dimensional nanostructure and diverse physical and chemical properties. This review examines the advancements achieved in biomedical applications through the integration of molybdenum disulfide (MoS2), and the state-of-the-art area of 3D printing technology. It initially outlines MoS2 synthesis routes and techniques to tailor its properties. The review explores how MoS2 properties underpin its biological significance, thereby facilitating its therapeutic, tissue engineering, and biosensing applications. Emphasis is placed on the emerging area of 3D printing, assessing its potential when combined with MoS2 to produce customized materials for biomedical purposes. Strategies to create foam topologies and electrocatalytically active filaments in 3D-printed constructs are explained. The enhanced mechanical strength, conductivity, and therapeutic efficacy observed in 3D-printed MoS2 structures foreshadow new developments in healthcare, including the advent of biocompatible implants for regenerative medicine and tissue engineering. Further results show how innovations have been made in biosensing areas leveraging MoS2 3D printing. These insights, grounded in scientific research, medical practices, and technological advancements, position MoS2 as a flexible and innovative material with diverse applications across various biomedical sectors.

Risk assessment for 3D printing in construction projects

Purpose The purpose of this study is to identify and assess new risks in construction projects that use 3D printing. Design/methodology/approach A mixed approach of both qualitative and quantitative methods was used. Literature review was conducted to extract 30 risks of 3D printing in construction. A survey was then developed to assess the probability and impact of these risks. In total, 37 respondents, who have experience and/or knowledge of 3D printing, completed the survey. The risk priority was calculated using a fuzzy logic approach. The main benefit of the proposed model is being able to use numerical and linguistic data in the risk assessment model. Findings The results show that the main risks, in terms of priority, are lack of codes and regulations for 3D printing in construction, delay in government approvals, shortage in labour skilled in 3D printed construction, lack of knowledge and information of 3D printed design concepts and changes in 3D construction codes and regulations. Originality/value This paper fills an identified gap in the literature related to 3D printing in construction and provides insights into the key risks affecting this disruptive technology.

3D Construction Printing as a Tool for Forming the Design Methodology of an Actual Modern Object of Architecture and Construction

An analysis of the experience of the design and construction of objects of modern architecture, reflecting in an aesthetic image, a high -tech direction and brightness of the image. In particular, the features of 3D construction printing with a variety of approaches and purposes of using this technology in the field of architecture are considered.The purpose of the research and analysis is to bring the theory of technological capabilities, their practical application and the relevance of modern architectural solutions into design methods, on the basis of which it is possible to form general trends and directions of aesthetic images of modern architecture.The article presents an approach to the design of a residential housing facility based on the analyzed experience and selected methods of architectural design, taking into account their subsequent implementation by 3D construction printing.

Design, calibration and performance evaluation of a small-scale 3D printer for accelerating research in additive manufacturing in construction

3D printing in construction presents numerous advantages, such as geometric flexibility, potential cost and time savings, the incorporation of recycled and sustainable materials, and reduced waste, thereby reducing the construction sector's environmental impact. Despite these advantages, the widespread adoption of AM in construction faces hurdles, primarily due to the prohibitive costs of large-scale concrete printers — typically ranging from $180,000 to over $1 million — and technological constraints that impede research and development efforts within the construction sector. To address these challenges, our study focuses on designing, developing, calibrating and evaluating an affordable lab-scale 3D printer specifically tailored for cement-based materials, aiming to lower the entry barrier for AM research in construction. This paper presents a proof-of-concept for a simple, yet functional printing technology that meet the requirements for research studies. The study details the development process, from the conceptual design to the calibration of printing parameters. The development process included the assessment of preliminary extrusion system designs integrated with the motion systems of a fused deposition modeling 3D printer. Subsequently, material studies were carried out to determine optimal material mix compositions and ratios. A comprehensive calibration of printing parameters using statistical analysis was proposed to ensure consistent and quality printing. The printability and applicability of the proposed small-scale 3D printer were assessed by printing samples and testing their thermal properties. Cost analysis showed that the proposed 3D printer, costing $273, offers benefits compared to existing market alternatives. The study illustrates the potential of small-scale 3D printers to facilitate construction research and practices, thereby promoting the development of sustainable construction methods.

Advancing sustainable construction: Terracotta component development through extrusion-based 3d printing with local clay

This study examines the use of 3D printing technology in construction, specifically the use of local clay as the primary material for developing Terracotta components. The results demonstrate the feasibility and high print quality achievable with clay, establishing it as a viable material for 3D printing in construction. The analysis of physical properties, such as shrinkage, density, and water absorption, provides valuable insights. Thermal conductivity, also examined, contributes to a comprehensive understanding of material performance. The article identifies the optimal extrusion parameters for terracotta components. The evaluations show that the water absorption rates are within standards, and the density variation ranges from 1420 to 1466 kg/m³. Additionally, there is a direct correlation between thermal conductivity and density. The compressive strengths are diverse, ranging from 18 MPa to 33 MPa. While modulus of elasticity provides essential quantitative data for understanding the mechanical behavior of printed samples when subjected to various stresses. The internal structure significantly influences compression resistance in 3D printed bricks, emphasizing its importance in design. This research highlights the potential of 3D printing, specifically with clay, in sustainable construction. It encourages further exploration of its practical applications in the industry.

Advances and Challenges in Immune-Modulatory Biomaterials for Wound Healing Applications.

Wound healing progresses through three distinct stages: inflammation, proliferation, and remodeling. Immune regulation is a central component throughout, crucial for orchestrating inflammatory responses, facilitating tissue repair, and restraining scar tissue formation. Elements such as mitochondria, reactive oxygen species (ROS), macrophages, autophagy, ferroptosis, and cytokines collaboratively shape immune regulation in this healing process. Skin wound dressings, recognized for their ability to augment biomaterials' immunomodulatory characteristics via antimicrobial, antioxidative, pro- or anti-inflammatory, and tissue-regenerative capacities, have garnered heightened attention. Notwithstanding, a lack of comprehensive research addressing how these dressings attain immunomodulatory properties and the mechanisms thereof persists. Hence, this paper pioneers a systematic review of biomaterials, emphasizing immune regulation and their underlying immunological mechanisms. It begins by highlighting the importance of immune regulation in wound healing and the peculiarities and obstacles faced in skin injury recovery. This segment explores the impact of wound metabolism, infections, systemic illnesses, and local immobilization on the immune response during healing. Subsequently, the review examines a spectrum of biomaterials utilized in skin wound therapy, including hydrogels, aerogels, electrospun nanofiber membranes, collagen scaffolds, microneedles, sponges, and 3D-printed constructs. It elaborates on the immunomodulatory approaches employed by these materials, focusing on mitochondrial and ROS modulation, autophagic processes, ferroptosis, macrophage modulation, and the influence of cytokines on wound healing. Acknowledging the challenge of antibiotic resistance, the paper also summarizes promising plant-based alternatives for biomaterial integration, including curcumin. In its concluding sections, the review charts recent advancements and prospects in biomaterials that accelerate skin wound healing via immune modulation. This includes exploring mitochondrial transplantation materials, biomaterial morphology optimization, metal ion incorporation, electrostimulation-enabled immune response control, and the benefits of composite materials in immune-regulatory wound dressings. The ultimate objective is to establish a theoretical foundation and guide future investigations in the realm of skin wound healing and related materials science disciplines.

A Compressive Load Bearing Analysis of 3D-Printed Circular Elements

Large-scale construction 3D printing is a promising platform technology that can be leveraged to fabricate structural elements such as columns, piers, pipes, and culverts. In this study, the axial compression and split tensile performance of 3D-printed steel-fiber-reinforced circular elements fabricated with different configurations (hollow, hybrid, mold-cast, and fully 3D-printed) is evaluated. This study further investigates the performance of multi-material circular hybrid elements (3D-printed shells with different backfilled core materials) in an attempt to assess their suitability as a new construction paradigm. The experimental results revealed that the fully 3D-printed steel-fiber-reinforced circular elements exhibited a higher load capacity (up to 36%) and a distinct crack pattern compared to the other configurations. The void ratio of circular elements has varying effects on its axial load capacity depending on the printing material and significantly influences its splitting tensile load capacity. Furthermore, the compatibility between the 3D-printed shell and the cast-in-place core is identified as an influential factor in the structural performance of the hybrid elements. The results suggest a promising construction approach where low-cement material can be utilized as infill material for a cost-effective 3D-printed permanent formwork, offering a viable solution for specific infrastructure development applications.

3D Printing and Implementation of Engineered Cementitious Composites - A Review

While 3D printing of concrete (3DCP) has gained increasing interest in the construction industry, steel reinforcement remains a significant obstacle to 3D printing (3DP) construction. To address this concern, Engineered Cementitious Composites (ECC), also recognized as Strain-Hardening Cementitious Composites (SHCC), can provide structural performance and integrity, safety, durability, and strength without steel reinforcement. The article reviews scientific works on 3DCP using ECC and proposes further investigations to lead to better development. As a result, generally, Poly-Ethylene (PE) fibers are used more frequently because of their strength. Mix design parameters have been extensively examined in relation to fresh ECC rheological characteristics. Due to the printing process, fiber orientation may affect ultimate tensile strain. As compared to casted ones with random fiber orientation, fiber orientation aligned with tensile stress resulted in a higher ultimate tensile strain. Additionally, research showed that ECC including up to 2 % fiber can be mixed, extruded, and built. Morovere, results highlighted the comparison between printed ECC containing PVA and PE fibers, the influence of mix design parameters on extrudability, and the impact of fiber length and volume fraction on strain-hardening properties. The text also covers the effects of fiber orientation and nozzle distance on tensile performance and ultimate tensile strain, as well as the anisotropic properties of 3DP-ECC. As well as this, there are some areas that require further research, such as durability and response to a variety of loading conditions, such as seismic loading.

Computer-aided design and 3D printing for a stable construction of segmental bone defect model in Beagles: a short term observation

ObjectiveSegmental bone defect animal studies require stable fixation which is a continuous experimental challenge. Large animal models are comparable to the human bone, but with obvious drawbacks of housing and costs. Our study aims to utilize CAD and 3D printing in the construction of a stable and reproducible segmental bone defect animal mode.MethodsCAD-aided 3D printed surgical instruments were incorporated into the construction of the animal model through preoperative surgical emulation. 20 3D printed femurs were divided into either experimental group using 3D surgical instruments or control group. In Vitro surgical time and accuracy of fixation were analysed and compared between the two groups. A mature surgical plan using the surgical instruments was then utilized in the construction of 3 segmental bone defect Beagle models in vivo. The Beagles were postoperatively assessed through limb function and imaging at 1, 2 and 3 months postoperatively.ResultsIn vitro experiments showed a significant reduction in surgical time from 40.6 ± 14.1 (23–68 min) to 26 ± 4.6 (19–36 min) (n = 10, p < 0.05) and the accuracy of intramedullary fixation placement increased from 71.6 ± 23.6 (33.3–100) % to 98.3 ± 5.37 (83–100) %, (n = 30, p < 0.05) with the use of CAD and 3D printed instruments. All Beagles were load-bearing within 1 week, and postoperative radiographs showed no evidence of implant failure.ConclusionIncorporation of CAD and 3D printing significantly increases stability, while reducing the surgical time in the construction of the animal model, significantly affecting the success of the segmental bone defect model in Beagles.

Digital Light Processing of 19F MRI-Traceable Gelatin-Based Biomaterial Inks towards Bone Tissue Regeneration.

Gelatin-based photo-crosslinkable hydrogels are promising scaffold materials to serve regenerative medicine. They are widely applicable in additive manufacturing, which allows for the production of various scaffold microarchitectures in line with the anatomical requirements of the organ to be replaced or tissue defect to be treated. Upon their in vivo utilization, the main bottleneck is to monitor cell colonization along with their degradation (rate). In order to enable non-invasive visualization, labeling with MRI-active components like N-(2,2-difluoroethyl)acrylamide (DFEA) provides a promising approach. Herein, we report on the development of a gelatin-methacryloyl-aminoethyl-methacrylate-based biomaterial ink in combination with DFEA, applicable in digital light processing-based additive manufacturing towards bone tissue regeneration. The fabricated hydrogel constructs show excellent shape fidelity in line with the printing resolution, as DFEA acts as a small molecular crosslinker in the system. The constructs exhibit high stiffness (E = 36.9 ± 4.1 kPa, evaluated via oscillatory rheology), suitable to serve bone regeneration and excellent MRI visualization capacity. Moreover, in combination with adipose tissue-derived stem cells (ASCs), the 3D-printed constructs show biocompatibility, and upon 4 weeks of culture, the ASCs express the osteogenic differentiation marker Ca2+.

3D printed sulfur-regolith concrete performance evaluation for waterless extraterrestrial robotic construction

By leveraging the capabilities of construction 3D printing, building structures in harsh extraterrestrial environments is conceivable. Sulfur concrete is a waterless construction material that offers great potential to replace Portland cement concrete (PCC) in extraterrestrial construction. The shape stability of 3D printed Martian sulfur-regolith concrete (SRC) was found to benefit from a lower substrate layer temperature. However, this comes at the cost of flexural strength, resulting in up to 53% strength loss. The printed SRC specimens demonstrated a significantly faster strength development rate (gaining about 85% of the ultimate strength after only 12 h) compared to the printed PCC. The printed SRC specimens also outperformed the PCC specimens in vacuum conditions at higher temperatures. Furthermore, modifying the SRC materials with Dicyclopentadiene resulted in up to 44% strength increase and minimized the sublimation rate of the printed specimens in vacuum, especially at an elevated temperature.

Structuration and yield strength characterization of hybrid alkali-activated cement composites (HACC) for ultra-rapid 3D construction printing

This study investigates the critical time-dependent rheological properties, including structuration rate and yield stress, of hybrid alkali-activated cement composites (HACC). HACC, a blend of geopolymer and cement paste, is examined to evaluate its suitability for ultra-rapid 3D construction printing (3DCP), which refers to a material’s ability to attain rapid structuration and buildability within 5–10 min after mixing, essential for additive manufacturing of 3D structures. The investigation extends to the impact of filler materials like silica sand and PVA fibers on HACC’s rapid structuration. Vicat needle, fast- and slow-penetration resistance measurements indicate that setting time increases with decreasing the Silicon/Aluminum (S/A) molar ratio and the addition of silica sand. Conversely, the addition of fibers reduces setting time while enhancing yield strength. Specifically, HACC mixtures with 0.5% and 1% PVA fiber additions, alongside combined sand (30%, 40%) and fiber (0.5%) mixtures, demonstrate ultra-rapid setting behavior within 3–5 min. Notably, mixtures with 40% silica sand and 0.5% PVA fiber exhibit highest yield strength development, i.e., 14 MPa at 12 min. Remarkably, incorporating 1% fibers into the HACC mixture yields the highest 28-day compressive strength (∼80 MPa) and flexural strength (∼11 MPa). The synergistic interplay between geopolymer and cement facilitates rapid setting time and high early-age strength development in HACC mixtures. The varying effects of silica sand and PVA fiber on setting time and yield strength provide opportunities for designing suitable structuration profiles. These findings underscore the exceptional rapid setting, structuration, and mechanical properties of HACC, positioning it as a promising material for ultra-rapid 3D construction printing.

Nanoporous, Gas Permeable PEGDA Ink for 3D Printing Organ‐on‐a‐Chip Devices

AbstractPolydimethylsiloxane (PDMS), commonly used in organ‐on‐a‐chip (OoC) systems, faces limitations in replicating complex geometries, hindering its effectiveness in creating 3D OoC models. In contrast, poly(ethylene glycol)diacrylate (PEGDA‐250), favored for its fabrication ease and resistance to small molecule absorption, is increasingly used for 3D printing microfluidic devices. However, applications in cell culture have been limited due to poor cell adhesion. Here, a nanoporous PEGDA ink (P‐PEGDA) is introduced to enhance cell adhesion. P‐PEGDA is formulated with a porogen, photopolymerized, followed by the porogen removal. Utilizing P‐PEGDA, complex microstructures, and membranes as thin as 27 µm are 3D‐printed. Porogen concentrations from 10 to 30% are tested yielding constructs with increasing porosity and oxygen permeability surpassing PDMS, without compromising printing resolution. Tests across four cell lines show &gt;80% cell viability, with a notable 77‐fold increase in MDA‐MB‐231 cell coverage on the porous scaffolds. Finally, an OoC model comprising a gyroid scaffold with a central opening filled with a cancer spheroid is introduced. This setup, after a 14 days co‐culture, demonstrates significant endothelial sprouting and integration within the spheroid. The P‐PEGDA formulation is suitable for high‐resolution 3D printing of constructs for 3D cell culture and OoC owing to its printability, gas permeability, biocompatibility, and cell adhesion.

3D Printing Technology and Future of Construction: A Review

Abstract Historically characterised by its labour-intensive nature and low productivity, the construction industry is witnessing a technological revolution. Among these advancements, 3D printing stands out as a frontrunner, offering the potential to automate construction processes, reduce material waste, shorten project timelines, and mitigate risks associated with manual labour. This study explores the transformative capacity of large-scale 3D printing in construction, examining current progress, potential trajectories, and inherent limitations. Furthermore, it assesses the impact of expanded 3D printing adoption on the construction labour market. Our findings highlight 3D printing’s potential to significantly diminish the need for manual labour, addressing labour shortages, particularly in countries reliant on immigrant labour forces. However, its effectiveness may vary in regions with competitive labour costs where manual labour remains prevalent. Integrating 3D printing in construction necessitates cultivating a specialised workforce with expertise in this innovative technology. In conclusion, this study underscores the transformative influence of 3D printing in construction, offering increased efficiency, reduced labour dependency, and solutions to industry challenges. Adapting 3D printing adoption to regional labour dynamics and workforce upskilling is essential for maximising its benefits. As the construction industry evolves, embracing 3D printing emerges as a pivotal factor in shaping its future landscape.

Economic analysis of offsite and onsite 3D construction printing techniques for low-rise buildings: A comparative value stream assessment

In comparison with traditional construction, 3D construction printing (3DCP) has the potential to be cost-effective due to its shorter supply chain and higher level of automation. Previous studies suggested that offsite 3DCP can be more capital-intensive than onsite 3DCP. Thus, there is a need for comprehensive research on the comparative economic analysis of offsite and onsite 3DCP techniques. Therefore, this study aims to investigate the overall construction cost of both techniques. In this regard, the Value stream assessment technique has been used to map the current state of the material flow from the supplier to the construction site. For the detailed cost analysis, mathematical models have been developed that consider transportation, warehousing, setup installation, printing, onsite assembly, and environmental costs based on the current state of Value stream mapping (VSM). The feasibility and practicality of the developed models have been validated through real-time case studies. Results from the cost breakdown analysis and cost based VSM show that offsite 3D printing leads to higher construction costs due to the significant contribution of warehousing costs for pre-printed components and the cost of assembling them. Cost based value stream assessment depicts that offsite and onsite 3DCP have a significant amount of non-value added cost (284.26 €/tonne and 199.05 €/tonne, respectively) and offer more space for process improvement. However, sensitivity analysis revealed that offsite 3DCP has the potential to reduce the transportation cost for small-scale projects involving low volume (<130 tonnes) of construction materials. Onsite 3D printing can be a feasible option for relatively larger projects due to its lower transportation, warehousing and construction costs. The findings of this research offer the construction industry a strategic roadmap to achieve cost-effectiveness and efficiency in construction practices.

In vivo study of a novel 3D-printed motion-preservation artificial cervical corpectomy construct: short-term imaging and biocompatibility evaluations in a goat model

BackgroundNonfusion technologies, such as motion-preservation devices, have begun a new era of treatment options in spine surgery. Motion-preservation approaches mainly include total disc replacement for anterior cervical discectomy and fusion. However, for multisegment fusion, such as anterior cervical corpectomy and fusion, the options are more limited. Therefore, we designed a novel 3D-printed motion-preservation artificial cervical corpectomy construct (ACCC) for multisegment fusion. The aim of this study was to explore the feasibility of ACCC in a goat model.MethodsGoats were treated with anterior C3 corpectomy and ACCC implantation and randomly divided into two groups evaluated at 3 or 6 months. Radiography, 3D CT reconstruction and MRI evaluations were performed. Biocompatibility was evaluated using micro-CT and histology.ResultsPostoperatively, all goats were in good condition, with free neck movement. Implant positioning was optimal. The relationship between facet joints was stable. The range of motion of the C2-C4 segments during flexion–extension at 3 and 6 months postoperatively was 7.8° and 7.3°, respectively. The implants were wrapped by new bone tissue, which had grown into the porous structure. Cartilage tissue, ossification centres, new blood vessels, and bone mineralization were observed at the porous metal vertebrae-bone interface and in the metal pores.ConclusionsThe ACCC provided stabilization while preserving the motion of the functional spinal unit and promoting bone regeneration and vascularization. In this study, the ACCC was used for anterior cervical corpectomy and fusion (ACCF) in a goat model. We hope that this study will propel further research of motion-preservation devices.

Development of novel 3D printable inks for protein delivery

The application of 3D printing technology in the delivery of macromolecules, such as proteins and enzymes, is limited by the lack of suitable inks. In this study, we report the development of novel inks for 3D printing of constructs containing proteins while maintaining the activity of the proteins during and after printing. Different ink formulations containing Pluronic F-127 (20–35 %, w/v), trehalose (2–10 %, w/v) or mannitol, poly (ethylene glycol) diacrylate (PEGDA) (0 or 10 %, w/w), and diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO, 0 or 0.2 mg/mL) were prepared for 3D-microextrusion printing. The F2 formulation that contained β-galactosidase (β-gal) as a model enzyme, Pluronic F-127 (30 %), and trehalose (10 %) demonstrated the desired viscosity, printability, and dose flexibility. The shear-thinning property of the F2 formulation enabled the printing of β-gal containing constructs with a good peak force during extrusion. After 3D printing, the enzymatic activity of the β-gal in the constructs was maintained for an extended period, depending on the construct design and storage conditions. For instance, there was a 50 % reduction in β-gal activity in the two-layer constructs, but only a 20 % reduction in the four-layer construct (i.e., 54.5 ± 1.2 % and 82.7 ± 9.9 %, respectively), after 4 days of storage. The β-gal activity in constructs printed from the F2 formulation was maintained for up to 20 days when stored in sealed bags at room temperatures (21 ± 2 °C), but not when stored unsealed in the same conditions (e.g., ∼60 % activity loss within 7 days). The β-gal from constructs printed from F2 started to release within 5 min and reached 100 % after 20 min. With the design flexibility offered by the 3D printing, the β-gal release from the constructs was delayed to 3 h by printing a backing layer of β-gal-free F5 ink on the constructs printed from the F2 ink. Finally, ovalbumin as an alternative protein was also incorporated in similar ink compositions. Ovalbumin exhibited a release profile like that of the β-gal, and the release can also be modified with different shape design and/or ink composition. In conclusion, ink formulations that possess desirable properties for 3D printing of protein-containing constructs while maintaining the protein activity during and after printing were developed.

Modelling, Analysis and Comparison of Robot Energy Consumption for Three-Dimensional Concrete Printing Technology

The technology used for the 3D printing of buildings from concrete is currently a very relevant and developing topic and appears to be especially advantageous in terms of sustainable production. An important aspect of the sustainability assessment is the energy efficiency of the printing robots. Printing robots consume a significant amount of energy when printing. It is important to analyse this energy thoroughly and to be able to predict it in order to optimise the movement and control of printing robots to reduce energy consumption. In that paper, we analyse in detail the energy consumption of printing robots, which has not yet been thoroughly investigated in the context of 3D printing building applications. We present a methodology to develop an energy consumption model for a printing robot, specifically developed and optimized for this technology. Our methodology incorporates an innovative approach to determine reduced-efficiency maps, allowing for the inclusion of difficult-to-measure drive efficiency parameters in the model. This results in a comprehensive model of the energy consumption of the printing robot, reflecting its operating characteristics in a real-world environment. An open control system of the printing robot is used for the measurement of energy quantities, and specially developed software tools are introduced. We also present the first direct comparison of the energy consumption of different printing robots when following a uniform printing trajectory. The comparison is made based on the presented methodology to obtain and compare actual energy data from workplaces with printing robots. The methodology combines measured data with energy simulations from ABB RobotStudio, enabling energy comparisons between industrially articulated robots and real printing robots, including the ABB IRB4600, the gantry printing robot, and the printing robot. The experiments clearly demonstrate that the kinematic structure of printing robots significantly affects their energy consumption in 3D printing concrete. Based on the conducted methodologies and analyses, we identify key aspects of energy consumption of printing robots in 3D Construction Printing or 3D Concrete Printing (3DCP) technology. In doing so, we bring a new perspective and provide a basis for further research and development in this previously understudied area.

3D Printing of Maturable Tissue Constructs Using a Cell‐Adaptable Nanocolloidal Hydrogel

Abstract3D‐printed cell‐laden hydrogels as tissue constructs show great promise in generating living tissues for medicine. Currently, the maturation of 3D‐printed constructs into living tissues remains challenge, since commonly used hydrogels struggle to provide an ideal microenvironment for the seeded cells. In this study, a cell‐adaptable nanocolloidal hydrogel is created for 3D printing of maturable tissue constructs. The nanocolloidal hydrogel is composed of interconnected nanoparticles, which is prepared by the self‐assembly and subsequent photocrosslinking of the gelatin methacryloyl solutions. Cells can get enough space to grow and migrate within the hydrogel through squeezing the flexible nanocolloidal networks. Meanwhile, the nanostructure can promote the seeded cells to proliferate and produce matrix proteins through mechanotransduction. Using digital light process‐based 3D printing technology, it can rapidly customize cartilage tissue constructs. After implantation, these tissue constructs efficiently matured into cartilage tissues for the articular cartilage defect repair and ear cartilage reconstruction in vivo. The 3D printing of maturable tissue constructs using the nanocolloidal hydrogel shows potential for future clinical applications.

Appraising the Feasibility of 3D Printing Construction in New Zealand Housing

The construction industry in New Zealand is significantly impacted by the importance of housing, particularly as urbanisation continues to grow in major cities. Modern construction methods, such as offsite construction and building automation, evolving into digital manufacturing and construction in the industry, have become prominent. Despite the global recognition of 3D printing technology, its adoption in the construction industry in New Zealand is still relatively limited. This study aims to examine the feasibility of 3D printing construction in response to current market challenges, innovation, and the 2050 net-zero carbon goal. Utilising Building Information Modelling (BIM) and Life Cycle Assessment (LCA) approaches, this study investigated the environmental impacts of three housing types: 3D printing (3DP), light steel framed (LSF), and timber. This study used cradle-to-cradle as the system boundary. The results indicate that the 3DP house emits 20% fewer carbon emissions than the traditional timber house and 25% less than the LSF house. Additionally, the 3DP house exhibits a 19% lower annual electric energy consumption than the timber house. Therefore, in response to the growing housing demand in New Zealand, the construction industry must innovate and embrace digital and advanced construction methods, including the adoption of 3D printing.