Three-dimensional Printing Research Articles

Application of electrospinning and 3D-printing based bilayer composite scaffold in the skull base reconstruction during transnasal surgery

Skull base defects are a common complication after transsphenoidal endoscopic surgery, and their commonly used autologous tissue repair has limited clinical outcomes. Tissue-engineered scaffolds prepared by advanced techniques of electrostatic spinning and three-dimensional (3D) printing was an effective way to solve this problem. In this study, soft tissue scaffolds consisting of centripetal nanofiber mats and 3D-printed hard tissue scaffolds consisting of porous structures were prepared, respectively. And the two layers were combined to obtain bilayer composite scaffolds. The physicochemical characterization proved that the nanofiber mat prepared by polylactide-polycaprolactone (PLCL) electrospinning had a uniform centripetal nanofiber structure, and the loaded bFGF growth factor could achieve a slow release for 14 days and exert its bioactivity to promote the proliferation of fibroblasts. The porous scaffolds prepared with polycaprolactone (PCL), and hydroxyapatite (HA) 3D printing have a 300 μm macroporous structure with good biocompatibility. In vivo experiments results demonstrated that the bilayer composite scaffold could promote soft tissue repair of the skull base membrane through the centripetal nanofiber structure and slow-release of bFGF factor. It also played the role of promoting the regeneration of the skull base bone tissue. In addition, the centripetal nanofiber structure also had a promotional effect on the regeneration of skull base bone tissue.

Tissue Engineering Nasal Cartilage Grafts with Three-Dimensional Printing: A Comprehensive Review.

Nasal cartilage serves a crucial structural function for the nose, where rebuilding the cartilaginous framework is an essential aspect of nasal reconstruction. Conventional methods of nasal reconstruction rely on autologous cartilage harvested from patients, which contributes to donor site pain and the potential for site-specific complications. Some patients are not ideal candidates for this procedure due to a lack of adequate substitute cartilage due to age-related calcification, differences in tissue quality, or due to prior surgeries. Tissue engineering, combined with three-dimensional printing technologies, has emerged as a promising method of generating biomimetic tissues to circumvent these issues to restore normal function and aesthetics. We conducted a comprehensive literature review to examine the applications of three-dimensional printing in conjunction with tissue engineering for the generation of nasal cartilage grafts. This review aims to compare various approaches and discuss critical considerations in the design of these grafts.

Influence of Material, Sterilization, and Disinfection on the Accuracy of Three-Dimensional Printed Surgical Templates: An InVitro Study.

To evaluate the influence of the three-dimensional (3D) printing technology, material, sterilization, and disinfection on the accuracy of guided surgical templates. Fifty printed resin surgical templates were designed and fabricated using a digital light processing 3D printer with a photopolymerizing resin, and 50 printed metal surgical templates were designed and fabricated using a selective laser melting 3D printer with a titanium alloy. Templates from both groups were randomly divided into five subgroups involving different sterilization and disinfection procedures. The group without any sterilization or disinfection procedure served as the control group, whereas the other groups were used as the study groups (hydrogen peroxide gas plasma sterilization, 5% povidone-iodine disinfection, 75% ethyl alcohol disinfection, and steam autoclave sterilization). Implant simulations were performed on the 3D-printed resin models, and postoperative impressions were acquired with scan bodies attached to the implants. All surgical templates were digitally scanned. The root mean square was used to determine and quantify fabrication accuracy and reproducibility, and the definitive and planned implant positions were compared. The printed resin templates exhibited lower fabrication accuracy and reproducibility, as well as higher 3D deviations, after steam autoclave sterilization (p < 0.001); however, the printed metal templates were not affected by the different sterilization or disinfection procedures (p > 0.05). Printed metal surgical templates are viable alternatives for guided implant surgery. Preoperative steam or gas plasma sterilization is recommended, especially for metal templates, as resin templates show deformation and decreased accuracy after steam sterilization. chictr.org.cn number: ChiCTR2400081334.

Experimental method for internal deformation measurement of 3D solids with embedded cracks based on 3D printing and digital speckle techniques

Quantification of the internal deformation of fractured solids such as rock masses under external loads, especially the deformation around internal fractures, is crucial for understanding and predicting the failure of fractured solids. However, it is very difficult to achieve the goal using conventional experimental methods. In this study, we proposed a novel internal deformation measurement method based on three-dimensional (3D) printing and digital speckle techniques. The 3D printing technology was applied to fabricate a 3D transparent model with an embedded elliptical crack and to set a speckle pattern on the internal section of the transparent model. The digital image correlation (DIC) method was used to determine the internal deformation field of the 3D fractured model. The measured displacements and strains of the internal sections in the fractured model were compared with the numerical simulation results. The comparison indicates that the proposed experimental method can well determine the deformation inside the 3D model. This built-in speckle method can realize real-time observation of the internal deformation of a 3D solid model in a non-contact and non-destructive manner.

Coalescence Mechanism Induced by Different Wetting States of Ti and Al Droplets on Rough Surfaces.

There is currently increasing interest in droplet transportation and coalescence on rough surfaces. However, the relationship among wettability, coalescence mode, and substrate characteristics (roughness and nanopillar height) remains unclear. In this work, two coalescence modes, climbing coalescence and contacting coalescence, are first observed in the dynamic behaviors of Ti and Al droplets on rough substrates. Due to the nonsynchronized wetting state transition of the droplets, the coalescence mode with increasing substrate characteristics differs, transitioning from contacting coalescence to climbing coalescence and then returning to the contacting mode. In general, the mode of coalescence correlates closely with the respective wetting states. Typically, Ti and Al droplets coalesce in the contacting mode when they have the same wetting state, but if they have different wetting states, they coalesce in the climbing mode. Our results emphasize the complicated relationship between the surface structure and the wettability of droplets, which could provide insights into self-assembly, three-dimensional printing, and microfluidic devices.

Evaluation of optical and mechanical properties of crown materials produced by 3D printing.

The various advantages of crown materials produced using three-dimensional (3D) printers have increased their use in restorative and prosthetic dentistry in recent years. Accordingly, their optical and mechanical properties have become more important. To evaluate the mechanical, surface and optical properties of crown materials produced with 3D printing and computer-aided design (CAD)/computer-aided manufacturing (CAM), which has recently been used frequently in the clinic. The 3-point bending test was used to evaluate the mechanical properties of 2 different crown materials produced with 3D printing (Permanent Crown and VarseoSmile Crown Plus) and a crown material produced using CAD/CAM (Vita Enamic). After the initial color and surface roughness measurements were made, the specimens were immersed in 4 different solutions. The most translucent material was VarseoSmile Crown Plus (p < 0.05). In all specimens, coffee caused the most discoloration (p < 0.05). The effects of the solutions on the roughness were mostly observed in Permanent Crown specimens (p < 0.05). Vita Enamic showed the highest statistically significant values in terms of flexural strength (p < 0.05). The stereolithographic technique among the materials produced by 3D printing can be recommended for use in restorations due to its higher flexural strength.

Ductile (Ag,Cu)2(S,Se,Te)-based auxetic metamaterials for sustainable thermoelectric power generation

Sustainable energy solution has resulted in significant interest in thermoelectric power generation, converting waste heat into electricity. However, the practical application of thermoelectric generators has been hindered by issues with their adaptability to arbitrary heat sources and durability in an operational environment. Here, we propose deformable auxetic thermoelectric metamaterials composed of high-entropy (Ag,Cu)2(S,Se,Te) ductile alloys, realized using finite element modelling and three-dimensional (3D) printing. We design a re-entrant auxetic structure with a negative Poisson’s ratio to maximize the mechanical deformability and develop an (Ag,Cu)2(S,Se,Te) particle-based colloidal 3D printable ink, tailored with Te microparticles. The 3D-printed (Ag,Cu)2(S,Se,Te) alloy exhibit a ZT value of 1.15 coupled with high compressive strength (208 MPa) and fracture strain (17.5 %). The fabricated auxetic metamaterials exhibit excellent vibrational stability and adaptability to diverse curved surfaces, realizing efficient power generation on a synclastic curved heat source. Our approach offers a method to design durable and efficient heat recovery devices.

The Design of Novel 3D-Printed, Moulded, and Oral Viscous Budesonide Formulations for Paediatrics: A Comparative Evaluation of Their Mucoadhesive Properties.

Paediatric eosinophilic oesophagitis (EoE) treatment is challenging due to the limited number of age-appropriate formulations. This study aims to develop and evaluate oral viscous suspensions and solid formulations of budesonide (BUD), focusing on their in vitro mucoadhesive properties, to enhance drug delivery and therapeutic outcomes in paediatric EoE. This study encompasses the development of oral viscous suspensions and orodispersible solid formulations (moulded tablets and 3D-printed dosage forms) containing BUD. The formulations underwent quality control tests as per the European Pharmacopoeia, chemical stability assessments, and an in vitro evaluation of their mucoadhesiveness properties. A validated analytical method enabled accurate BUD quantification and efficient extraction, and all developed formulations demonstrated chemical stability for 30 days, meeting Ph. Eur. quality standards. Three-dimensional printing using SSE successfully produced 1 mg and 0.5 mg BUD printlets, complying with quality tests for conventional tablets. Formulations containing xanthan gum (L2-XG and P1-0.5-XG) exhibited superior mucoadhesive properties. L2-XG showed significantly higher mucoadhesion than L1-MC. Among the solid formulations, P1-0.5-XG demonstrated the highest mucoadhesive properties. This is the first study to develop solid oral dosage forms of BUD at a very low dose, specifically for paediatric use. The results highlight the potential of 3D printing for developing individualised orodispersible BUD formulations with improved bioadhesion for paediatric EoE treatment. The L2-XG formulation and the XG-containing printlets are the most promising formulations in terms of increasing contact time with the oesophageal mucosa, which could translate into improved therapeutic efficacy in this patient population.

Evaluation of Mechanical Properties of ABS-like Resin for Stereolithography Versus ABS for Fused Deposition Modeling in Three-Dimensional Printing Applications for Odontology.

This study investigates the differences in mechanical properties between acrylonitrile butadiene styrene (ABS) samples produced using fused deposition modeling (FDM) and stereolithography (SLA) using ABS filaments and ABS-like resin, respectively. The central question is to determine how these distinct printing techniques affect the properties of ABS and ABS-like resin and which method delivers superior performance for specific applications, particularly in dental treatments. The evaluation methods used in this study included Shore D hardness, accelerated aging, tensile testing, Izod impact testing, flexural resistance measured by a 3-point bending test, and compression testing. Poisson's ratio was also assessed, along with microstructure characterization, density measurement, confocal microscopy, dilatometry, wettability, Fourier-transform infrared spectroscopy (FTIR), and nanoindentation. It was concluded that ABS has the same hardness in both manufacturing methods; however, the FDM process results in significantly superior mechanical properties compared to SLA. Microscopy demonstrates a more accurate sample geometry when fabricated with SLA. It is also concluded that printable ABS is suitable for applications in dentistry to fabricate models and surgical guides using the SLA and FDM methods, as well as facial protectors for sports using the FDM method.

Current Applications of the Three-Dimensional Printing Technology in Neurosurgery: A Review.

In the recent years, three-dimensional (3D) printing technology has emerged as a transformative tool, particularly in health care, offering unprecedented possibilities in neurosurgery. This review explores the diverse applications of 3D printing in neurosurgery, assessing its impact on precision, customization, surgical planning, and education. A literature review was conducted using PubMed, Web of Science, Embase, and Scopus, identifying 84 relevant articles. These were categorized into spine applications, neurovascular applications, neuro-oncology applications, neuroendoscopy applications, cranioplasty applications, and modulation/stimulation applications. 3D printing applications in spine surgery showcased advancements in guide devices, prosthetics, and neurosurgical planning, with patient-specific models enhancing precision and minimizing complications. Neurovascular applications demonstrated the utility of 3D-printed guide devices in intracranial hemorrhage and enhanced surgical planning for cerebrovascular diseases. Neuro-oncology applications highlighted the role of 3D printing in guide devices for tumor surgery and improved surgical planning through realistic models. Neuroendoscopy applications emphasized the benefits of 3D-printed guide devices, anatomical models, and educational tools. Cranioplasty applications showed promising outcomes in patient-specific implants, addressing biomechanical considerations. The integration of 3D printing into neurosurgery has significantly advanced precision, customization, and surgical planning. Challenges include standardization, material considerations, and ethical issues. Future directions involve integrating artificial intelligence, multimodal imaging fusion, biofabrication, and global collaboration. 3D printing has revolutionized neurosurgery, offering tailored solutions, enhanced surgical planning, and invaluable educational tools. Addressing challenges and exploring future innovations will further solidify the transformative impact of 3D printing in neurosurgical care. This review serves as a comprehensive guide for researchers, clinicians, and policymakers navigating the dynamic landscape of 3D printing in neurosurgery.

Research progress on femoral attachment positioning during medial patellofemoral ligament reconstruction

To review research progress on femoral attachment positioning during medial patellofemoral ligament (MPFL) reconstruction, so as to provide a reference for accurate positioning in clinic. The literature at home and abroad on femoral attachment positioning during MPFL reconstruction was extensively reviewed and summarized. MPFL is the main ligament that restricts patellar outward migration, so MPFL reconstruction is the main treatment for patellar dislocation, but the accuracy of intraoperative femoral attachment positioning will significantly affect the effectiveness. At present, there are three main methods for femoral attachment positioning in MPFL reconstruction, including imaging positioning, bony landmark positioning, and new technology. Among them, the main imaging positioning method is the "Schöttle point" method, but it has high requirements for fluoroscopic positioning, and can only be accurately positioned under standard lateral fluoroscopy of the femur. The bony landmark positioning method mainly locates the femoral attachment by touching or dissecting the bony landmarks such as adductor tubercles and medial epicondyle of femur, but its disadvantages are that the positioning is not accurate enough, the intraoperative visual field exposure requirements are high, and a large incision is required. In order to avoid the problem that the simple bony landmark positioning method, in recent years, the combination of bony landmarks combined with arthroscopy, three-dimensional (3D) printing technology, and robot-assisted positioning methods have begun to be used in clinical practice. New technology localization methods have shown good results by preparing guides before operation, planning positioning paths in advance, or directly using robots to assist positioning during operation. The accurate positioning of the femoral attachment in MPFL reconstruction is crucial, and the method of accurate and rapid intraoperative determination needs to be further improved and optimized. In the future, it is expected that the combination of computer image recognition correction technology and intraoperative position assistance will solve this problem.

A new path planning strategy driven by geometric features and tensile properties for 3D printing of continuous fiber reinforced thermoplastic composites

Three-dimensional (3D) printing technology for continuous fiber reinforced thermoplastic composites (C-FRTP), capable of rapid manufacturing of lightweight components with intricate geometric features, has emerged as one of the most promising technologies in the field of advanced composite manufacturing. Path planning is a crucial step for determining the fabrication quality of C-FRTP components. This study proposed a new 3D printing path planning strategy driven by the geometric features and tensile properties of C-FRTP components. The strategy employed the properties of the Euler graph to generate the continuous full-field filling paths, ensuring the geometric features of the target components. The intersections were scattered along the printing path to enhance the tensile strength. The feasibility and advantages of the new path planning strategy were validated by comparative experiments with different printing paths. The results indicated that the new strategy not only achieved the geometric features of the target components but significantly enhanced their tensile strength. Using the printing path generated by the new path planning strategy, the tensile strength of specimens featuring mounting holes reached 349.4 MPa, which was only about 4.1 % lower than the tensile strength of continuous fibers at straight paths. Compared to the existing contour-parallel path, the new strategy in this work improved the tensile properties by about 40.9 %. The new path planning strategy proposed in this study shows great potential to design and fabricate C-FRTP components with enhanced mechanical properties for practical applications.

Research progress in repair and reconstruction of tumor-related bone defects in proximal femur

To review the repair and reconstruction methods for large segmental femoral proximal bone defects caused by tumors, and to explore their clinical application effects, advantages, and disadvantages, and future research directions. A comprehensive search of Chinese and foreign databases was conducted to select basic and clinical research literature related to the repair and reconstruction of femoral proximal bone defects caused by tumors. The studies were classified and analyzed based on two main strategies: hip-preserving reconstruction and non-hip-preserving reconstruction. In hip-preserving reconstruction, traditional methods such as allograft transplantation and vascularized autograft transplantation are common but have risks of poor bone integration and bone resorption. The clinical application of inactivated tumor segment reimplantation and distraction osteogenesis techniques is limited. In recent years, three-dimensional printing technology has become increasingly mature, with personalized prostheses and precise surgeries becoming development trends. Non-hip-preserving reconstruction primarily includes allograft prosthesis composite and total femoral replacement. The former focuses on improving the survival rate and bone integration efficiency of the allograft, while the latter requires the simultaneous reconstruction of hip and knee joint stability. Significant progress has been made in repairing and reconstructing proximal femoral bone defects caused by tumors, but many challenges remain. The integration of three-dimensional printing technology and digital design offers potential for precise bone defect repair. Future efforts should focus on new concepts, technologies, and materials through multidisciplinary approaches to provide personalized and precise solutions, thereby improving patient quality of life.

State of art on evaluation of three- to six-dimensional novel additive manufacturing technology for biomedical applications

Additive manufacturing has evolved over the last few decades. Three-dimensional printing is a digital manufacturing technology that provides nearly endless options for the creation of an accessible instrument for all parts of various medical practices, including tissue engineering, through meticulous optimization of material, processing, and geometry for every point in an object. Three-dimensional printing has opened up a new, faster, and safer manufacturing process, despite its incapability to fabricate complex structures and objects. Recently, novel four-dimensional printing techniques have been developed for the transformation of typical stable three-dimensional printed parts into smart objects. The limitations of three-dimensional printing could be remedied with four-dimensional printing, by applying time as the fourth dimension. Self-repairing and speedy printing are two additional benefits of this technology's by using smart materials. By adapting this technology, numerous medical domains could be profited. Four-dimensional printing does not have the ability to produce curved complicated forms. However, five-dimensional printing overcomes the flaws seems in four-dimensional printing. Five-dimensional additive manufacturing relies on the rotation of both the print bed and the extruder head. Five-dimensional printing outlasts in terms of durability than three- and four-dimensional printing. Currently, a combination of the principles of four- and five-dimensional printing into a single process is called six-dimensional printing. In six-dimensional printing, the form changes over time due to the reaction of environmental factors, which is primarily used in biomedical applications. This paper summarizes extensive research on biomaterials in the field of biomedical science and discusses the present implications of three-, four-, five-, and six-dimensional printing techniques.

High-Fidelity Sensing Modality for Anomaly Detection in Inkjet Printing

Abstract Inkjet three-dimensional (3D) printing has emerged as a transformative manufacturing technique, finding applications in diverse fields such as biomedical, metal fabrication, and functional materials production. It involves precise deposition of materials onto a moving substrate through a nozzle, achieving submillimeter scale resolution. However, the dynamic nature of droplet deposition introduces uncertainties, challenging consistent quality control. Current process monitoring, relying on image-based techniques, is slow and limited, hindering real-time feedback in erratic droplet ejection. In response to these challenges, we present the zero-dimensional ultrafast sensing (0-DUS) system, a novel, cost-effective, in situ monitoring tool designed to assess the quality of drop-on-demand inkjet printing. The 0-DUS system leverages the sensitivity of the light-beam field interference effect to rapidly and precisely detect and analyze localized droplets. Two core technical advancements drive this innovation: first, the exploration of integral sensing of the computational light-beam field, which allows for efficient extraction of temporal and spatial information about droplet evolution, introducing a novel in situ sensing modality; second, the establishment of a robust mapping mechanism that aligns sensor data with image-based data, facilitating accurate estimation of droplet characteristics. We successfully implemented the 0-DUS system within a commercial inkjet printer and conducted a comparative analysis with ground truth data. Our experimental results demonstrate a detection accuracy exceeding 95%, even at elevated speeds, allowing for an impressive in situ certification throughput of up to 500 Hz. Consequently, our proposed 0-DUS system meets the stringent quality assurance requirements, thereby expanding the potential applications of inkjet printing across a wide spectrum of industrial sectors.

The effectiveness of 3d printing technology course on attitudes of occupational therapy students-a controlled study

There is interest in three-dimensional (3D) printing technology, but views on the integration of these technologies into business and education vary. It is crucial to determine how the introduction of new technologies will impact the attitudes of occupational therapy undergraduate students. Hence, the purpose of this study is to examine the effect of using this technology in the assistive technology (AT) lesson on the attitudes and acceptance of technology among students. This study was designed as a non-randomized controlled pretest and posttest control group study. The intervention group consisted of second-year undergraduate students (n = 50) enrolled in a compulsory “AT course,” while the control group consisted of third-year undergraduate students (n = 41) who had completed the AT course in the previous academic year. The intervention involved participants attending a 3D printing course in combination with an 8-week AT course. A Modified Technology Acceptance Model (M-TAM) questionnaire was used to assess students’ acceptance of 3D printing technology. The related study observed that experiencing and practicing new technologies, such as 3D printing and modeling course in the intervention group AT lesson effectively increased the acceptability of these new technologies that students encountered. The pre-post test analysis of the intervention group was statistically significant in all categories of the M-TAM questionnaire (p < 0.05). Compared to the control group, the effect size was small and moderate in all categories (p < 0.05). This course has increased student acceptance of this technology. Future studies should examine the long-term effects of such courses on student attitudes.

Microfluidic Wearable Electrochemical Sensor Based on MOF-Derived Hexagonal Rod-Shaped Porous Carbon for Sweat Metabolite and Electrolyte Analysis.

Wearable sensors enable the noninvasive continuous analysis of biofluid, which is of great importance for healthcare monitoring. In this work, a wearable sensor was seamlessly integrated with a microfluidic chip which was prepared by a three-dimensional printing technology for noninvasive and multiplexed analysis of metabolite and electrolytes in human sweat. The microfluidic chip could enable rapid sampling of sweat, which avoids the sweat evaporation and contamination. Using a Zn metal-organic framework as a sacrificial template, the hexagonal rod-shaped porous carbon nanorod (PCN) with high porosity, a large specific surface area, and excellent conductivity was synthesized and exhibited the robust electrocatalytic ability of uric acid (UA) oxidation. Therefore, the PCN-based sensor showed high sensitivity and good selectivity of UA with a wide linear range of 10-200 μM and a low detection limit of 4.13 μM. Meanwhile, the potentiometry-based ion-selective electrode was constructed for detection of pH and K+, respectively, with good sensitivity, selectivity, reproducibility, and stability. In addition, the testing under different bending states demonstrated that mechanical deformation had little effect on the electrochemical performance of the wearable sensors. Furthermore, we evaluated the utility of the wearable sensor for multiplexed real-time analysis of UA, pH, and K+ in sweat during aerobic exercise, and the effect of the amount of consumed purine-rich foods on uric acid metabolite levels in sweat and urine was further investigated. The relationship between urine UA and sweat UA was obtained. Overall, this wearable sensor enables multiple electrolyte and metabolite analysis in different noninvasive biofluids, suggesting its potential application in personalized disease prevention.

Pepgen-P15 delivery to bone: A novel 3D printed scaffold for enhanced bone regeneration

Pepgen-P15 is a combination of an organic hydroxyapatite matrix derived from bovine sources, combined with a synthetic peptide known as P-15. The interaction between α2β1 integrin and the P15 chain triggers both intracellular and extracellular signaling pathways, resulting in the production of growth factors. Three-dimensional (3D) printing has recently emerged as an innovative strategy for developing personalized therapies in bone tissue regeneration. In this research, various ratios of calcium magnesium silicate (bredigite) nanoparticles were used to modify 3D printed scaffolds made of xanthan gum and polycaprolactone (PCL) via fused deposition modeling (FDM). Scaffolds were subsequently treated with an alkaline solution, covered with graphene oxide, and finally, Pepgen-P15 was applied. the effects of xanthan gum were assessed using swellability and contact angle tests. The results indicated that, the prepared scaffolds exhibited suitable degradation rates, mechanical characteristics, and apatite formation. Alizarin red and alkaline phosphatase assays were also conducted to evaluate the scaffolds’ effectiveness in promoting bone cell differentiation during cell culture. Furthermore, the surface of the scaffold was examined to determine the amount of Pepgen-P15 loaded and released. According to the findings, the scaffold composed of 20 % bredigite and 0.3 % graphene oxide, coated with Pepgen-P15, demonstrate optimal mechanical properties, cell adherence, development, and proliferation. Typically, it is a good candidate for use in bone tissue engineering.

Valved Microwell Array Platforms for Stepwise Liquid Dispensing.

The fabrication of microarray chips and the precise dispensing of nanoliter to microliter liquids are fundamental for high-throughput parallel biochemical testing. Conventional microwells, typically featuring a uniform cross section, fill completely in a single operation, complicating the introduction of multiple reagents for stepwise and combinatorial analyses. To overcome this limitation, we developed an innovative valved microwell array. Using ultraviolet (UV)-curing resin three-dimensional (3D) printing, these multilayer configurations can be rapidly fabricated through direct template printing and polydimethylsiloxane (PDMS) casting. Each microwell incorporates a microvalve structure, truncating fluids within the upper metering well and allowing transfer to the bottom reservoir well under centrifugal force. Sequential operations enable the introduction of multiple reagents, facilitating orthogonal combinations for complex assays. We explored four types of valving methods: DeepWell, Expansion, Bottleneck, and Membrane valve, each offering varying degrees of design complexity, operational efficiency, robustness, and precision. These methods constitute a versatile toolkit to accommodate a broad spectrum of analytical requirements. Our innovative approach redefines microwell architecture, direct manufacturing techniques, and stepwise fluid dispensation in microarrays.

Customized bioresin formulation for stereolithography in tissue engineering

Recently, advancements in fabrication technology have brought a new aspect to the field of tissue engineering. By utilizing advanced techniques in 3D manufacturing and biomaterials, scientists have successfully created tissue engineering scaffolds with complex three-dimensional structures and customized chemical compositions that closely mimic the natural environment of living tissues. These methodologies show potential not only for developing therapies that restore lost tissue function but also for creating in vitro models that replicate living tissue. The current investigation involved the synthesis of methacrylated polycaprolactone (PCLMA) by incorporating methacryloyl chloride (Meth-Cl) into polycaprolactone (PCL) with a molecular weight of 80,000 Da. Afterwards, PCLMA was subjected to crosslinking with glycerol acrylate (GA) and, by utilizing Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as a photoinitiator, achieved the three-dimensional (3D) printing of tissue materials using Stereolithography (SLA). Analytical techniques included nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Cell viability was investigated using Human Osteoblast (HOB) cells. The biocompatibility of glycerol acrylate (GA) crosslinked polymethacrylated polycaprolactone (PCLMA) was confirmed using cell viability experiments. Overall, the GA-crosslinked PCLMA bioresin, particularly PCLMA-8, shows promise for further use in tissue engineering applications.