Annals of 3D printed medicine最新文献

Porous scaffolds have evolved, allowing personalised 3D-printed structures that can improve tissue reconstruction. By using scaffolds with specific porosity, Poisson's ratio and stiffness, load-bearing tissues such as tibial reconstruction can be improved. Recent studies suggest the potential for negative Poisson's ratio ($-\upsilon$) meta-scaffolds in mimicking the behaviour of natural tissue, leading to improved healing and tissue reintegration. This study reveals a porous meta-scaffold that offers high $-\upsilon$ and can be personalised to match desired stiffness. By using laser powder bed fusion (L-PBF) of CoCrMo, a porous structure was created, characterised by its ability to achieve heightened $-\upsilon$. Prototype testing and numerical modelling unveiled a proxy-model capable of predicting and personalising the porosity, yield strength, elastic modulus, and $-\upsilon$ of the tibial meta-scaffold representing a novel contribution to the field. The surrogate model also aids characterising the impact of design variables such as of the scaffold on the key performance requirements of the tibial scaffold. This approach enables the fabrication of porous biomaterials with personalised properties, specifically suited for load-bearing tibial reconstruction. The resulting meta-scaffold offers $-\upsilon$ ranging from -0.16 to -0.38, porosity between 73.46% and 85.36%, yield strength of 30–80 MPa, and elastic modulus ranging from 8.6 to 22.6 GPa. The optimised architecture feature $-\upsilon$ of 0.223 and a targeted elastic modulus of 17.53 GPa, while also showcasing yield strength and porosity of 57.2 MPa and 76.35%, respectively. By combining 3D printing with tailored scaffolds, this study opens doors to mass customisation of improved load-bearing porous biomaterials that of negative Poisson's ratio and stiffness matching.

Introduction

The development of biomaterials and medical devices for burn wound treatment necessitates thorough investigation through in vitro/ex vivo models before transitioning to animal studies. Establishing a standardized and high-throughput burn wound model in ex vivo skin presents a considerable challenge. Our objective was to address this challenge by developing a practical and cost-effective 3D-printed burn wound tool capable of uniformly inducing burns in 12 skin samples simultaneously.

Material and methods

Utilizing Autodesk Inventor software, we designed a 3D model comprising a plate-base component (PBC) and a rod-base component (RBC). The design was exported as a Standard Triangulation Language (STL) file, processed through "Slicer" software to generate a G-code file tailored for 3D printing.

Results

The Rod-Base component underwent iterative design modifications to optimize weight, airflow, and material consumption, resulting in a final design featuring a unique star shape for enhanced airflow. Simultaneously, the Plate-Base component design evolved to enable easy and secure plate placement, demonstrating compatibility with 12-well plates. The average production time for the model was 14.5 h, with a production cost of approximately $20 (USD), covering printing material and steel rods.

Conclusion

In conclusion, this study provides valuable insights into the required equipment and software, empowering researchers to efficiently produce their accurate and cost-effective 3D-printed tool for controlled and reproducible burn wound creation in ex vivo viable skin tissues.

Three-dimensional (3D) bioprinting technology allows the production of porous structures with complex and varied geometries, which facilitates the development of equally dispersed cells and the orderly release of signal components. This is in contrast to the traditional methods used to produce tissue scaffolding. To date, 3D bioprinting has employed a range of cell-laden materials, including organic and synthetic polymers, to construct scaffolding systems and manufacture extracellular matrix (ECM). Still, there are several challenges in meeting the technical issues in bio-ink formulations, such as the printability of bio-inks, the customization of mechanical and biological properties in bio-implants, the guidance of cell activities in biomaterials, etc. The main objective of this article is to discuss the various strategies for preparing bio-inks to mimic native tissue's extracellular matrix environment. A discussion has also been conducted about the process parameters of bio-ink formulations and printing, structure requirements, and fabrication methods of durable bio-scaffolds. The present study also reviews various 3D-printing techniques. Conclusively, the challenges and potential paths for smart bioink/scaffolds have been outlined for tissue regeneration.

Background

Tricuspid regurgitation (TR) treatments have gradually shifted toward a more interventional approach and transcatheter edge-to-edge repair (TEER) has assumed a first-order role. TriClip™ by Abbott (Menlo Park, USA) is one of the most widely used devices for tricuspid repair. TEER procedures are recognised as technically challenging, characterized by a steep learning curve. For this reason, specialized training is necessary. The aim of this work is to develop and test a novel 3D printed training simulator, which considers both anatomical and mechanical characteristics, specifically designed for this kind of procedure.

Methods

Starting from routinely acquired computed tomography (CT) images, a 3D digital model of the heart was reconstructed. This was then properly “augmented”, so that it could realistically reproduce the key features involved in the procedure. The simulator was manufactured exploiting the Polyjet 3D printed. Proper materials selection was performed to accurately reproduce mechanical properties. The manufactured prototype was then tested by a specialized professional, with the TriClip™ system.

Results

The simulator was assessed to practice access, navigation, catheter steering and leaflet grasping. Throughout the process, appropriately placed cameras ensured that the operators could visualize the crucial steps on a screen. Even if a deeper evaluation is needed, preliminary feedback is satisfactory.

Conclusions

In this study, a new training simulator for TriClip™ procedure was designed, produced, and preliminary assessed. Further studies will have to demonstrate the advantages of using this simulator design to shorten the learning curve and subsequently lead to better clinical outcomes.

Background

Compartment syndrome is a medical emergency. It should be diagnosed promptly, and therapeutic measures should be taken to avoid limb ischemia. Measurement of compartment pressure is extremely important.

Model

Knowledge about compartments and familiarity with the pressure monitoring device are important to diagnose acute compartment syndrome properly. Simulations provide an opportunity to learn the device and practice the procedure. Given their lower cost and the possibility of frequent reproduction, simulations using 3D-printed material are gaining popularity. We propose a simple low-fidelity model using a silicone-based lower leg soft tissue, 3D-printed tibia and fibula, Foley catheter, and syringes.

Conclusion

This low-fidelity simulator helps to improve procedural skills and retention through repeated practice.

Introduction

Distal radius fractures make up around 20% of adult fractures, varying in type and severity, thus requiring different treatments. Cast immobilization is effective in indicated fractures, but is associated with several disadvantages such that 3D-printed orthoses (3D-Braces) have been introduced as a potentially advantageous alternative. The present study was designed to test the hypothesis that short-arm 3D-printed Polylactic Acid (PLA) orthoses would provide superior biomechanical properties when compared to plaster of Paris short-arm casts for immobilization of distal radial fractures.

Methods

Modified mannequin forearms were utilized as human models for the creation of both the circular casts and the 3D Braces. A total of five plaster cast prototypes were produced, based on a standard cylindrical plaster cast application technique used in the treatment of distal radius fractures, and another five samples were 3D printed braces. Each sample was then subjected to a three-point bend load test, using an Instron 68SC2 testing machine, and the data was collected and exported to an Excel spreadsheet and analyzed using SPSS Statistics version 26 (IBM Corp., Armonk, N.Y., USA).

Results

The 3D-Braces can withstand significantly higher forces at yield and maximum force, implying they may offer superior mechanical stability. Moreover, our findings indicated a higher strain at yield for the 3D-Braces compared to conventional plaster casts.

Conclusions

3D-printed Polylactic Acid short-arm orthoses demonstrated superior biomechanical properties when compared to plaster of Paris short-arm casts designed for immobilization of distal radial fractures. Taken together with data from previous studies, preclinical evidence suggests that PLA 3D-Braces can effectively maintain distal radius fracture alignment and stability with potential advantages over traditional casts with respect to biomechanical properties as well as post-fabrication adjustment, patient hygiene, comfort, and daily activities.

Background

Ocular injuries are common complaints in the emergency department (ED). In certain instances, a hematoma builds up behind the eyeball and can lead to increased intraocular pressure (IOP), restricting circulation and threatening vision. A lateral canthotomy can be vision-saving if performed appropriately and quickly. Unfortunately, not every physician in the ED is familiar with the procedure.

Objective

Our objective was to build a hybrid 3D-printed model to simulate lateral canthotomy, hence improving physicians’ skills in performing the procedure.

Method

Using a MakerBot 3D printer, a hemi-cranium and a sphere imitating the eyeball were printed. The model is supplemented with silicon skin and other materials. A hematoma is created using chocolate pudding. We present a low-fidelity, long-lasting hybrid model for lateral canthotomies. This model simulates the pathology, anatomy, and basic technical steps required to perform the procedure.

Conclusion

This low-fidelity simulator helps to improve procedural skills and retention through repeated practice.

3D printing, or additive manufacturing, has transformed various industries with its layer-by-layer fabrication approach. In medicine, 3D printing, or biofabrication, has seen significant advancements, particularly in the creation of patient-specific medical models and custom-made drug tablets. Bioprinting, a key aspect of biofabrication, encompasses three approaches: biomimicry, autonomous self-assembly, and microtissues, each with its unique advantages and disadvantages. This comprehensive review explores the merits and limitations of these bioprinting approaches and outlines the three main phases of the entire bioprinting process: pre-processing, processing, and post-processing. By enhancing patients’ quality of life, reducing healthcare costs, and tapping into the global medical device market, biofabrication technologies hold immense promise for the future of medicine. This literature review focuses on the applications of 3D printing technologies in creating medical devices, including bone tissues, joint tissues, 3D printed tablets, and medical models.

In this work, we developed and analyzed a biphasic calcium phosphate (BC_P) bioceramic for bone regeneration using stereolithography (SLA). The SLA method is a promising additive manufacturing (AM) technique capable of creating BCp parts with high accuracy and efficiency. However, the ceramic suspension used in SLA exhibits significantly higher viscosity and is not environmentally friendly. Therefore, adequate preparation of a suspension with low viscosity and high solid loading is essential. In this paper, we optimized the effects of surfactant doses and solid loading on the BCp slurry, and initially examined the process parameters of photocuring, debinding, and sintering. The utilization of 9 wt % Disperbyk (BYK) with a 40 vol % loading of BCp bioceramics exhibited a reasonably low viscosity of 8.9 mPa·s at a shear level of 46.5 s⁻¹. Functional and structural analyses confirmed that BCp was retained after photocuring and subsequent treatment, which were incorporated into the BYK dispersion. The 3D printed objects with different sintered temperatures, specifically at 1100 °C, 1200 °C, and 1300 °C, were further optimized. Additionally, the surface roughness, porosity, and mechanical properties of BCp green parts were systematically investigated. Most importantly, in vitro analysis of cell attachment, differentiation, and red alizarin analysis could support the application of bone regeneration.