Three-dimensional printing in orthopaedic surgery: A review of current and future applications.

Three-dimensional (3D) printing is a form of technology in which 3D physical models are created. It has been used in a variety of surgical specialities ranging from cranio-maxillo-facial to orthopaedic surgery and is currently an area of much interest within the medical profession. Within the field of orthopaedic surgery, 3D printing has several clinical applications including surgical education, surgical planning, manufacture of patient-specific prostheses/patient specific instruments and bone tissue engineering. This article reviews the current practices of 3D printing in orthopaedic surgery in both clinical and pre-clinical settings along with discussing its potential future applications.

Architectural design and optimization of internal structures in 3D printed electrodes for superior supercapacitor performance.

The architecture of electrodes plays a pivotal role in the transfer and transportation of charges during electrochemical reactions. Selecting optimal electrode materials and devising well-conceived electrode structures can substantially enhance the electrochemical performance of devices. This manuscript leverages 3D printing technology to fabricate asymmetric supercapacitor devices featuring regular layered configurations. By investigating the impact of various materials on the internal architecture of printed electrodes, we establish a stratified electrode structure with an orderly arrangement, thereby significantly improving asymmetric charge transfer between electrodes. The application of 3D printing technology to construct electrode structures effectively mitigates the agglomeration of electrode materials. The 3D-printed VCG//MXene devices demonstrate exceptional areal capacitance (205.57 mF cm-2) and energy density (60.03 µWh cm-2), with a power density of 0.174 W cm-2. Consequently, selecting appropriate materials for fabricating printable electrode structures and achieving efficient 3D printing is anticipated to offer novel insights into the construction and enhancement of miniature asymmetric micro-supercapacitor (MSCs) devices.

Wetting of soap bubbles on topographic surfaces.

HYPOTHESIS: There is a relationship between the static contact angle of droplets and soap bubbles on flat homogeneous surfaces, therefore, it should be possible to derive a relationship between the static contact angle of a soap bubble on a periodic topographic surface and a droplet on a flat homogeneous surface. EXPERIMENTS: A free energy model of the static contact angle of soap bubbles on a topographic surface in the Cassie-Baxter state was derived. Polydimethylsiloxane surfaces of varying area fraction (0.125, 0.250, 0.500, 0.750, and 1.00) and periodic topographies (lined and pillared) were fabricated using 3D printed moulds for pattern transfer. A bubble goniometer was developed to accommodate bubbles of 40,000 ± 5,000 mm3 and 50,000 ± 5,000 mm3 volumes. Then, the static contact angle of bubbles of both volumes were measured on the varying topographic surfaces. FINDINGS: The derived predictions imply that the relationship between the static contact angle for bubbles on a flat homogeneous surface and on a composite surface, has the same form as the Cassie-Baxter equation for a droplet. The experimental results for the measured static contact angle for both bubble volumes on the varying surfaces had good agreement with the predicted trends.

3D printing of highly conductive and strongly adhesive PEDOT:PSS hydrogel-based bioelectronic interface for accurate electromyography monitoring.

PEDOT: PSS hydrogel-based bioelectronic interfaces have gained significant attention in various fields including biomedical devices, wearable devices, and epidermal electronics. However, the development of high-performance bioelectronic interfaces that integrate excellent conductivity, strong adhesion, and advanced processing compatibility remains a challenge. Herein, we develop a high-performance bioelectronic interface by 3D printing of a novel poly(vinyl alcohol-formaldehyde) (PVAF)-PEDOT:PSS composite ink. Such a PEDOT:PSS-PVAF ink exhibits favorable rheological properties for direct-ink-writing 3D printing, enabling the fabrication of high-resolution patterns and three-dimensional structures with high aspect ratios. Hydrogel bioelectronic interface printed by such PEDOT:PSS-PVAF ink simultaneously achieves high conductivity (over 100 S m-1), strong adhesion (31.44 ± 7.07 kPa), as well as stable electrochemical performance (charge injection capacity of 13.72 mC cm-2 and charge storage capacity of 18.80 mC cm-2). We further integrate PEDOT:PSS-PVAF hydrogel bioelectronic interface to fabricate adhesive skin electrodes for electromyography (EMG) signal recording. The resultant EMG skin electrodes demonstrate superior performance and stability compared to commercial products, maintaining high signal-to-noise ratio of > 10 dB under varying weights and repetitive motions. These advantageous performance of PEDOT:PSS-PVAF based hydrogel bioelectronic interfaces may be helpful for diverse bioelectronic applications like healthcare monitoring and epidermal bioelectronics.

Detection properties of indium-111 and IRDye800CW for intraoperative molecular imaging use across tissue phantom models.

Significance: Intraoperative molecular imaging (IMI) enables the detection and visualization of cancer tissue using targeted radioactive or fluorescent tracers. While IMI research has rapidly expanded, including the recent Food and Drug Administration approval of a targeted fluorophore, the limits of detection have not been well-defined. Aim: The ability of widely available handheld intraoperative tools (Neoprobe and SPY-PHI) to measure gamma decay and fluorescence intensity from IMI tracers was assessed while varying characteristics of both the signal source and the intervening tissue or gelatin phantoms. Approach: Gamma decay signal and fluorescence from tracer-bearing tumors (TBTs) and modifiable tumor-like inclusions (TLIs) were measured through increasing thicknesses of porcine tissue and gelatin in custom 3D-printed molds. TBTs buried beneath porcine tissue were used to simulate IMI-guided tumor resection. Results: Gamma decay from TBTs and TLIs was detected through significantly thicker tissue and gelatin than fluorescence, with at least 5% of the maximum signal observed through up to 5 and 0.5 cm, respectively, depending on the overlying tissue type or gelatin. Conclusions: We developed novel systems that can be fine-tuned to simulate variable tumor characteristics and tissue environments. These were used to evaluate the detection of fluorescent and gamma signals from IMI tracers and simulate IMI surgery.

3D printed polylactic acid/polyethylene glycol/bredigite nanocomposite scaffold enhances bone tissue regeneration via promoting osteogenesis and angiogenesis.

Recently, the fabrication of personalized scaffolds with high accuracy has been developed through 3D printing technology. In the current study, polylactic acid/polyethylene glycol (PLA/PEG) composite scaffolds with varied weight percentages (0, 5, 10, 20 and 30 %) of bredigite nanoparticles (B) were fabricated using the 3D printing and then characterized through scanning electron microscopy and Fourier transform infra-red spectroscopy. The addition of B nanoparticles up to 20 wt% to PLA/PEG scaffold increased the compressive strength (from 7.59 to 13.84 MPa) and elastic modulus (from 142.42 to 268.33 MPa). The apatite formation ability as well as inorganic ion release in simulated body fluid were investigated for 28 days. The MG-63 cells viability and adhesion were enhanced by increasing the amount of B in the PLA/PEG scaffold and the osteogenic differentiation of the rat bone marrow mesenchymal stem cells was confirmed by alkaline phosphatase activity test and alizarin red staining. According to chorioallantoic membrane assay, the highest angiogenesis occurred around the PLA/PEG/B30 scaffold. In vivo experiments on a rat calvarial defect model demonstrated an almost complete recovery in the PLA/PEG/B30 group within 8 weeks. Based on the results, the PLA/PEG/B30 composite scaffold is proposed as an optimal scaffold to repair bone defects.

Tragacanth gum hydrogels with cellulose nanocrystals: A study on optimizing properties and printability.

This study investigates a novel all-polysaccharide hydrogel composed of tragacanth gum (TG) and cellulose nanocrystals (CNCs), eliminating the need for toxic crosslinkers. Designed for potential tissue engineering applications, these hydrogels were fabricated using 3D printing and freeze-drying techniques to create scaffolds with interconnected macropores, facilitating nutrient transport. SEM images revealed that the hydrogels contained macropores with a diameter of 100-115 µm. Notably, increasing the CNC content within the TG matrix (30-50 %) resulted in a decrease in porosity from 83 % to 76 %, attributed to enhanced polymer-nanocrystal interactions that produced denser networks. Despite the reduced porosity, the hydrogels demonstrated high swelling ratios (890-1090 %) due to the high water binding capacity of the hydrogel. Mechanical testing showed that higher CNC concentrations significantly improved compressive strength (27.7-49.5 kPa) and toughness (362-707 kJ/m3), highlighting the enhanced mechanical properties of the hydrogels. Thermal analysis confirmed stability up to 400 °C and verified ionic crosslinking with CaCl2. Additionally, hemolysis tests indicated minimal hemolytic activity, affirming the biocompatibility of the TG/CNC hydrogels. These findings highlight the potential of these hydrogels as advanced materials for 3D-printed scaffolds and injectable hydrogels, offering customizable porosity, superior mechanical strength, thermal stability, and biocompatibility.

Transapical Transcatheter Aortic Valve Replacement Under 3-Dimensional Guidance to Treat Pure Aortic Regurgitation in Patients with a Large Aortic Annulus.

Background: Transcatheter aortic valve replacement (TAVR) is a challenge for patients with aortic regurgitation (AR) and a large annulus. Our goal was to evaluate the clinical outcomes and predictors of transapical TAVR in AR patients with a large annulus and noncalcification and the feasibility and safety of 3-dimensional printing (3DP) in the preprocedural simulation. Methods: Patients with a large annulus (diameter >29 mm) were enrolled and divided into the simulation (n = 43) and the nonsimulation group (n = 82). Surgeons used the specific 3DP model of the simulation group to simulate the main steps before the procedure and to refit the transcatheter heart valve (THV) according to the simulated results. Results: The average annular diameter of the overall cohort was 29.8 ± 0.7 mm. Compared with the nonsimulation group, the simulation group used a higher proportion of extra oversizing for THVs (97.6% vs. 85.4%, p = 0.013), and the coaxiality performance was better (9.7 ± 3.9° vs. 12.7 ± 3.8°, p < 0.001). Both THV displacement and ≥ mild paravalvular leakage (PVL) occurred only in the nonsimulation group (9.8% vs. 0, p < 0.001; 9.8% vs. 0, p < 0.001). Multivariate regression analysis showed that extra oversizing, coaxial angle and annulus diameter were independent predictors of THV displacement and ≥ mild PVL, respectively. Conclusions: Based on 3DP guidance, transapical TAVR using extra oversizing was safe and feasible for patients with noncalcified AR with a large annulus. Extra oversizing and coaxial angle were predictors of postprocedural THV displacement and ≥ mild PVL in such patients.

Influence of silver coated zeolite fillers on the chemical and mechanical properties of 3D-printed polyphenylene sulfone restorations.

OBJECTIVES: To investigate the chemical and mechanical properties of polyphenylene sulfone (PPSU) depending on its composition and manufacturing. METHODS: Unfilled-PPSU1 and with antimicrobial silver coated zeolites filled-PPSU2 specimens were made of granulate-GR, filament-FI, or printed-3D. Scanning microscopy and X-ray spectroscopy were performed. Martens hardness-HM, elastic indentation modulus-EIT and flexural strength-FS were determined initially and after aging. Shear bond strength-SBS to veneering and luting composite after conditioning with 7 adhesive systems were examined after aging. Silver leaching was tested after 1-, 3-, 7-, 14-, 21-, 28- and 42 days. Analyses of variance, Kolmogorov-Smirnov, Kruskal-Wallis, Mann-Whitney U, unpaired t-tests and Weibull modulus were computed (p < 0.05). RESULTS: Zeolites were homogeneously distributed. PPSU1-GR and PPSU1-FI showed the highest HM/EIT, followed by PPSU2-GR, PPSU1-3D and PPSU2-3D. PPSU2-FI presented the lowest HM/EIT, displaying micro pits. Aging showed reduced HM/EIT in PPSU1 and no impact on PPSU2, while FS increased (PPSU1) or decreased (PPSU2). PPSU2-3D presented lower FS than PPSU1-3D. High SBS to the luting (7.0-16.2 MPa) and veneering composite (11.8-22.2 MPa), except for adhesive system PR, were observed. PPSU2-3D showed the highest silver release (9.6%), with all compositions dispensing silver over 42 days. CONCLUSIONS: For the examined period of 6 weeks, antimicrobial silver ions were released from filled PPSU. The high SBS between PPSU and veneering/luting composite confirmed the feasibility of esthetically veneering and luting filled PPSU. To achieve mechanical properties like unfilled PPSU, the processing parameters of filled PPSU require refinement. CLINICAL SIGNIFICANCE: This investigation provides proof of principle that PPSU can be successfully doped with silver-coated zeolites. The combination of 3D-printing with an antimicrobial thermoplastic constitutes a great opportunity in the field of prosthetic dentistry. Potential applications include clasps for removable dental prostheses, provisional or permanent fixed dental prostheses and implant abutments.

A portable micro-nanochannel bio-3D printed liver microtissue biosensor for DON detection.

We investigated a portable micro-nanochannel biosensor 3D-printed liver microtissues for rapid and sensitive deoxynivalenol (DON) detection. The screen-printed carbon electrode (SPCE) was modified with nanoporous anodic aluminum oxide (AAO), gold nanoparticles (AuNPs), and cytochrome C oxidase (COx) to enhance sensor performance. Gelatin methacrylate hydrogel, combined with hepatocellular carcinoma cells, formed the bioink for 3D printing. Liver microtissues were prepared through standardized and high-throughput techniques via bio-3D printing technology. These microtissues were immobilized onto modified electrodes to fabricate liver microtissue sensors. The peak current of this biosensor was positively correlated with DON concentration, as determined by cyclic voltammetry (CV), within a linear detection range of 2∼40 µg/mL. The standard curve equation is denoted by ICV(µA) = = 18.76956 + 0.03107CDON(µg/mL), with a correlation coefficient R2 was 0.99471(n＝3). A minimum detection limit of 1.229 µg/mL was calculated from the formula, indicating the successful construction of a portable micro-nanochannel bio-3D printed liver microtissue biosensor. It provides innovative ideas for developing rapid and convenient instrumentation to detect mycotoxin hazards after grain production. It also holds significant potential for application in the prediction and assessment of post-production quality changes in grain.

Engineered Shape-Morphing Transitions in Hydrogels Through Suspension Bath Printing of Temperature-Responsive Granular Hydrogel Inks.

4D printing of hydrogels is an emerging technology used to fabricate shape-morphing soft materials that are responsive to external stimuli for use in soft robotics and biomedical applications. Soft materials are technically challenging to process with current 4D printing methods, which limits the design and actuation potential of printed structures. Here, a simple multi-material 4D printing technique is developed that combines dynamic temperature-responsive granular hydrogel inks based on hyaluronic acid, whose actuation is modulated via poly(N-isopropylacrylamide) crosslinker design, with granular suspension bath printing that provides structural support during and after the printing process. Granular hydrogels are easily extruded upon jamming due to their shear-thinning properties and their porous structure enables rapid actuation kinetics (i.e., seconds). Granular suspension baths support responsive ink deposition into complex patterns due to shear-yielding to fabricate multi-material objects that can be post-crosslinked to obtain anisotropic shape transformations. Dynamic actuation is explored by varying printing patterns and bath shapes, achieving complex shape transformations such as 'S'-shaped and hemisphere structures. Furthermore, stepwise actuation is programmed into multi-material structures by using microgels with varied transition temperatures. Overall, this approach offers a simple method to fabricate programmable soft actuators with rapid kinetics and precise control over shape morphing.

Direct Ink Writing 3D Printing Elastomeric Polyurethane Aided by Cellulose Nanofibrils.

3D printing of a flexible polyurethane elastomer is highly demandable for its potential to revolutionize industries ranging from footwear to soft robotics thanks to its exceptional design flexibility and elasticity performance. Nevertheless, conventional methods like fused deposition modeling (FDM) and vat photopolymerization (VPP) polyurethane 3D printing typically limit material options to thermoplastic or photocurable polyurethanes. In this research, a water-borne polyurethane ink was synthesized for direct ink writing (DIW) 3D printing through the incorporation of cellulose nanofibrils (CNFs), enabling direct printing of complex, monolithic elastomeric structures at room temperature that can maintain the designed structure. Additionally, a solvent-induced fast solidification (SIFS) method was introduced to facilitate room-temperature curing and enhance mechanical properties. The 3D-printed WPU structures demonstrated strong interfacial adhesion, exhibiting high ultimate tensile strength of up to 22 MPa and an elongation at break of 951%. The 3D-printed WPU structures also demonstrated outstanding resilience and durability, capable of enduring more than 100 cycles of compression and tension as well as withstanding vehicle crushing and heavy lifting. This method also shows suitability for 3D printing complex structures such as a vase and an octopus.

Pharmacy 3D printing.

A significant limitation of the "one size fits all" medication approach is the lack of consideration for special population groups. 3D printing technology has revolutionised the landscape of pharmaceuticals and pharmacy practice, playing an integral role in enabling on-demand production of customised medication. Compared to traditional pharmaceutical processes, 3D printing has major advantages in producing tailored dosage forms with unique drug release mechanisms. Moreover, this technology has enabled the combination of multiple drugs in a single formulation addressing key issues of medication burden. Development of 3D printing in clinical applications and large-scale pharmaceutical manufacturing has substantially increased in recent years. This review focuses on the emergence of extrusion-based 3D printing, particularly semi solid extrusion, fused deposition modelling and direct powder extrusion, which are currently the most commonly studied in pharmacy practice. The concept of each technique is summarised, with examples of current and potential applications. Next, recent advancements in the 3D printer market and pharmacist perceptions are discussed. Finally, the benefits, challenges and prospects of pharmacy 3D printing technology are highlighted, emphasising its significance in changing the future of this field.

3D Printed Leaf-Vein-Like Al2O3/EP Biohybrid Structures with Enhanced Thermal Conductivity.

The high computility of electronic components put urgent requirements on the dissipation efficiency of a high thermal conductive substrate. Herein, inspired by the nature structure, leaf-vein-like Al2O3 skeleton was first designed though topology optimization algorithm and manufactured via vat photopolymerization (VPP) 3D printing, then compounded with epoxy (EP) to prepare leaf-vein-like biohybrid structures. The biohybrid structure had a high λ (14.65 Wm-1 K-1 with the solid fraction of 40 vol %), which was 5585% higher than neat EP and 269% higher than the random dispersed Al2O3/EP composite at the same solid amount. Moreover, it further showed a high enhancement in the cooling ecoefficiency of the lighting-emitting diode (LED) cooling system. Compared with 40 vol % random dispersed Al2O3/EP composite as a cooling substrate, the leaf-vein-like biohybrid structure with the same solid fraction reduced the working temperature of LED by 8.9 °C. Our strategy has a significant potential as a viable type and mass-producible bionic cooling substrate.

4D-printed shape-programmable [H+]-responsive needles for determination of urea.

Four-dimensional printing (4DP) technologies are revolutionizing the fabrication, functionality, and applicability of stimuli-responsive analytical devices. More practically, 4DP technologies are effective in fabricating devices with complex geometric designs and functions, and the degree of shape programming of 4D-printed stimuli-responsive devices can be optimized to become a reliable analytical strategy. Although shape-programming modes play a critical role in determining the analytical characteristics of 4D-printed stimuli-responsive sensing devices, the effect of shape-programming modes on the analytical performance of 4D-printed stimuli-responsive devices remains an unexplored subject. We employed digital light processing three-dimensional printing (3DP) with acrylate-based photocurable resins and 2-carboxyethyl acrylate (CEA)-incorporated photocurable resins for 4DP of the bending, helixing, and twisting needles. Upon immersion in samples with pH values above the pKa of CEA, the electrostatic repulsion among the dissociated carboxyl groups of polyCEA caused swelling of the CEA-incorporated part and [H+]-dependent shape programming. When coupling with the derivatization reaction of the urease-mediated hydrolysis of urea, the decline in [H+] induced shape programming of the needles, offering reliable determination of urea based on the shape-programming angles. After optimizing the experimental conditions, the helixing needles provided the best analytical performance, with the method's detection limit of 0.9 µM. The reliability of this analytical method was validated by determining urea in samples of human urine and sweat, fetal bovine serum, and rat plasma with spike analyses and comparing these results with those obtained from a commercial assay kit. Our demonstration and analytical results suggest the importance of optimizing the shape-programming modes to improve the analytical performance of 4D-printed stimuli-responsive shape-programming sensing devices and emphasize the benefits and applicability of 4DP technologies in advancing the development and fabrication of stimuli-responsive sensing devices for chemical sensing and quantitative chemical analyses.

Three-dimensional printed polyelectrolyte construct containing mupirocin-loaded quaternized chitosan nanoparticles for skin repair.

Despite substantial advancements in wound dressing development, effective skin repair remains a significant challenge, largely due to the persistent issue of recurrent infections. Three-dimensional printed constructs that integrate bioactive and antibacterial agents hold significant potential to address this challenge. In this study, a 3D-printed hydrogel scaffold composed of polyallylamine hydrochloride (PAH) and pectin (Pc), incorporated with mupirocin (Mp)-loaded quaternized chitosan nanoparticles (QC NPs) was fabricated. The primary objective of this study was to facilitate a controlled and sustained release of Mp via the QC NPs. The average size of QC-Mp nanoparticles was measured to be 66.05 nm and the average strand diameter and pore size of the 3D-printed construct were measured as 147.22 ±â€¯5.83 and 388.44 ±â€¯14.50 µm, respectively. The hemolysis rate of all scaffolds was below 2 %, indicating that they can be classified as non-hemolytic materials with sufficient blood compatibility. The PAH-Pc/QC-Mp scaffold exhibited significant antibacterial activity, enhanced cell viability in HaCat cells, sustained Mp release until day 7 (⁓60 %), and in-vivo wound healing promotion by stimulation of human keratinocytes. In conclusion, the proposed biocompatible construct demonstrates significant potential for the treatment of chronic and infected wounds by preventing infection and promoting accelerated wound healing.

Impact Deposition of a Single Droplet of Low-Melting-Point Alloy as the Top Electrode for Organic Photovoltaics.

Top electrodes of organic photovoltaics (OPVs) are usually thermally evaporated in the vacuum, which is non-continuous and time-consuming and has been the bottleneck for the OPV fabrication process. Printable top electrodes that are free of vacuum, high temperature, and solvents will make OPVs more attractive. Low-melting-point alloys (LMPAs) are promising candidates for printable OPV electrodes thanks to the merits of matching work functions, high electron conductivity, high environment stability, and no need for post-treatment. Here, LMPA electrodes are directly deposited on OPVs by simply falling a single LMPA droplet onto the substrate. The LMPA droplet spreads to form a thin film with a smooth interface intimately contacting the substrate. The electrode area can be tailored by adjusting the droplet diameter or the Weber number, which is the ratio of inertia to surface tension. The interface morphology is mainly affected by the contact temperature. The degree of oxidation and charges on the droplet can also influence the electrode area and interface morphology. OPVs with droplet-impacted LMPA electrodes exhibit power conversion efficiencies of up to 16.17%. This work demonstrates the potential of single-droplet impact deposition as a simple method for printing OPV electrodes for scalable manufacturing.

4D-Flow MRI and Vector Ultrasound in the In-Vitro Evaluation of Surgical Aortic Heart Valves - a Pilot Study.

INTRODUCTION: The aim of this study was the initial investigation of 4D-Flow MRI and Vector Ultrasound as novel imaging techniques in the in-vitro analysis of hemodynamics in anatomical models. Specifically, by looking at the hemodynamic performance of state-of-the-art surgical heart valves in a 3D-printed aortic arch. METHODS: The mock circulatory loop simulated physiological, pulsatile flow. Two mechanical and three biological aortic valves prostheses were compared in a 3D-printed aortic arch. 4D magnetic resonance imaging and vector flow Doppler ultrasound served as imaging methods. Hemodynamic parameters such as wall shear stress, flow velocities and pressure gradients were analyzed. RESULTS: The flow analysis revealed characteristic flow-patterns in the 3D-printed aortic arch. The blood-flow in the arch presented complex patterns, including the formation of helixes and vortices. Higher proximal peak velocities and lower flow volumes were found for biological valves. CONCLUSION: The mock circulatory loop in combination with modern radiological imaging provides a sufficient basis for the hemodynamic comparison of aortic valves.

Inertial microfluidic mixer for biological CubeSat missions.

Nanosatellites of CubeSat type due to, i.a., minimized costs of space missions, as well as the potential large application area, have become a significant part of the space economy sector recently. The opportunity to apply miniaturized microsystem (MEMS) tools in satellite space missions further accelerates both the space and the MEMS markets, which in the coming years are considered to become inseparable. As a response to the aforementioned perspectives, this paper presents a microfluidic mixer system for biological research to be conducted onboard CubeSat nanosatellites. As a high complexity of the space systems is not desired due to the need for failure-free and remotely controlled operation, the principal concept of the work was to design an entirely passive micromixer, based on lab-on-chip technologies. For the first time, the microfluidic mixer that uses inertial force generated by rocket engines during launch to the orbit is proposed to provide an appropriate mixing of liquid samples. Such a solution not only saves the space occupied by standard pumping systems, but also reduces the energy requirements, ultimately minimizing the number of battery modules and the whole CubeSat size. The structures of the microfluidic mixers were fabricated entirely out of biocompatible resins using MultiJet 3D printing technology. To verify the functionality of the passive mixing system, optical detection consisting of the array of blue LEDs and phototransistors was applied successfully. The performance of the device was tested utilizing an experimental rocket, as a part of the Spaceport America Cup 2023 competition.

Advancements in Tissue Engineering: A Review of Bioprinting Techniques, Scaffolds, and Bioinks.

Tissue engineering is a multidisciplinary field that uses biomaterials to restore tissue function and assist with drug development. Over the last decade, the fabrication of three-dimensional (3D) multifunctional scaffolds has become commonplace in tissue engineering and regenerative medicine. Thanks to the development of 3D bioprinting technologies, these scaffolds more accurately recapitulate in vivo conditions and provide the support structure necessary for microenvironments conducive to cell growth and function. The purpose of this review is to provide a background on the leading 3D bioprinting methods and bioink selections for tissue engineering applications, with a specific focus on the growing field of developing multifunctional bioinks and possible future applications.