Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (39)

Search Parameters:
Keywords = 3D-printed capsule

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
16 pages, 2915 KB  
Article
Extrusion-Based 3D Printing of Rutin Using Aqueous Polyethylene Oxide Gel Inks
by Oleh Koshovyi, Jyrki Heinämäki, Alina Shpychak, Andres Meos, Niklas Sandler Topelius and Ain Raal
Pharmaceutics 2025, 17(7), 878; https://doi.org/10.3390/pharmaceutics17070878 - 3 Jul 2025
Viewed by 653
Abstract
Background/Objectives. Flavonoids are a vast class of phenolic substances. To date, approximately 6000 plant-origin flavonoids have been discovered, with many of them being used in drug therapy. Therapeutic flavonoids are commonly formulated to conventional “one-size-fits-all” dosage forms, such as conventional tablets or hard [...] Read more.
Background/Objectives. Flavonoids are a vast class of phenolic substances. To date, approximately 6000 plant-origin flavonoids have been discovered, with many of them being used in drug therapy. Therapeutic flavonoids are commonly formulated to conventional “one-size-fits-all” dosage forms, such as conventional tablets or hard capsules. However, the current trends in pharmacy and medicine are centred on personalised drug therapy and drug delivery systems (DDSs). Therefore, 3D printing is an interesting technique for designing and preparing novel personalised pharmaceuticals for flavonoids. The aim of the present study was to develop aqueous polyethylene oxide (PEO) gel inks loaded with rutin for semisolid extrusion (SSE) 3D printing. Methods. Rutin (a model substance for therapeutic flavonoids), Tween 80, PEO (MW approx. 900,000), ethanol, and purified water were used in PEO gels at different proportions. The viscosity and homogeneity of the gels were determined. The rutin–PEO gels were printed with a bench-top Hyrel 3D printer into lattices and discs, and their weight and effective surface area were investigated. Results. The key SSE 3D-printing process parameters were established and verified. The results showed the compatibility of rutin as a model flavonoid and PEO as a carrier polymer. The rutin content (%) and content uniformity of the 3D-printed preparations were assayed by UV spectrophotometry and high-performance liquid chromatography (HPLC). Conclusions. The most feasible aqueous PEO gel ink formulation for SSE 3D printing contained rutin 100 mg/mL and Tween 80 50 mg/mL in a 12% aqueous PEO gel. The 3D-printed dosage forms are intended for the oral administration of flavonoids. Full article
(This article belongs to the Special Issue 3D Printing of Drug Delivery Systems)
Show Figures

Graphical abstract

12 pages, 3074 KB  
Article
Mechanical Properties and Material Characteristics of 3D-Printed Titanium Capsules for Cancer Drug Delivery Applications
by Katarzyna Kazimierska-Drobny, Grzegorz Szala, Janusz Musiał, Marek Macko, Tomasz Karasiewicz and Jakub Lewandowski
Materials 2025, 18(13), 2969; https://doi.org/10.3390/ma18132969 - 23 Jun 2025
Viewed by 612
Abstract
The aim of the study was to assess the mechanical and material properties of porous titanium capsules, produced by 3D printing via the DMLS (Direct Metal Laser Sintering) technique based on their potential application as carriers for anticancer drugs. The study used capsules [...] Read more.
The aim of the study was to assess the mechanical and material properties of porous titanium capsules, produced by 3D printing via the DMLS (Direct Metal Laser Sintering) technique based on their potential application as carriers for anticancer drugs. The study used capsules made from the Ti-6Al-4V alloy, and analyzes the impact of geometric parameters, structural features, and printing angles (0°, 45°, and 90°) on their compressive strength. A total of 36 capsules were tested, 18 of type KTD and 18 of type KTM, each in two loading directions. The surface roughness and damage characteristics resulting from mechanical loading have also been evaluated. Statistical analysis of the results was performed using Student’s t-test. The results show that the capsules printed at an angle of 45° are characterized by the highest compressive strength, while their resistance significantly exceeds the values typical of human bone tissue. Additionally, the observed damage does not lead to the formation of sharp edges or loose fragments, which confirms the safety of their use in the body. The high surface roughness promotes tissue integration and limits capsule migration after implantation. The analyses confirm the potential of 3D-printed titanium capsules as effective and safe drug carriers in personalized anticancer therapy. Full article
Show Figures

Figure 1

19 pages, 5644 KB  
Article
3D Printing of PVA Capsular Devices for Applications in Compounding Pharmacy: Stability Evaluation and In Vivo Performance
by Juan Francisco Peña, Daniel Andrés Real, Juan Pablo Real, Santiago Daniel Palma, María del Pilar Zarazaga, Nicolás Javier Litterio, Loreana Gallo and Ivana Maria Cotabarren
Pharmaceutics 2025, 17(5), 613; https://doi.org/10.3390/pharmaceutics17050613 - 5 May 2025
Cited by 1 | Viewed by 946
Abstract
Background: The personalization of medication through 3D printing enables the development of capsular devices (CDs) tailored to patient-specific needs. This study aimed to evaluate the stability and in vivo performance of 3D-printed polyvinyl alcohol (PVA) CDs with 0.4 and 0.9 mm width [...] Read more.
Background: The personalization of medication through 3D printing enables the development of capsular devices (CDs) tailored to patient-specific needs. This study aimed to evaluate the stability and in vivo performance of 3D-printed polyvinyl alcohol (PVA) CDs with 0.4 and 0.9 mm width wall thicknesses (WT) compared to traditional hard gelatin capsules (HGCs). Methods: Capsules were tested for swelling, erosion, adhesion, water sorption, and in vitro disintegration. Additionally, the release of the model drug (losartan potassium) from CDs was evaluated. In vivo capsule opening times were assessed in dogs using X-ray imaging. Stability studies were conducted under natural (25 ± 2 °C, 60 ± 5% RH) and accelerated (40 ± 2 °C, 75 ± 5% RH) storage conditions. Results: CDs with 0.4 mm WT (CD–0–0.4) exhibited higher swelling and erosion, lower adhesion, and faster disintegration, leading to a more immediate drug release, comparable to HGCs. A strong correlation was found between in vitro and in vivo disintegration behavior. Water sorption tests revealed lower moisture affinity for PVA CDs compared to HGC. Stability studies showed that CD–0–0.4 retained its physical and chemical properties. Instead, CDs with 0.9 mm WT (CD–0–0.9) were sensitive to storage, particularly under accelerated aging, which affected their integrity and release profile. Conclusions: These findings highlight the potential of PVA-CDs, especially the 0.4 mm design, as a promising and stable alternative for compounding pharmacy applications, offering an effective platform for personalized oral drug delivery. Full article
Show Figures

Figure 1

10 pages, 6432 KB  
Article
Three-Dimensionally Printed Gypsum Located Within Micro-Encapsulated Phase Change Material: Thermal Conductivity Benefits of Selective Activation Technique
by Marwa El Yassi, Alexandre Pierre, Valentine Danché, Ikram Darcherif and Yannick Mélinge
Appl. Sci. 2025, 15(4), 1929; https://doi.org/10.3390/app15041929 - 13 Feb 2025
Cited by 2 | Viewed by 1083
Abstract
The widespread occurrence of encapsulated phase change materials (PCMs) within a mineral matrix has been demonstrated to improve the thermo-physical properties of final products. The upscaling of such materials has not yet been achieved, as traditional onsite mixing and casting processes could damage [...] Read more.
The widespread occurrence of encapsulated phase change materials (PCMs) within a mineral matrix has been demonstrated to improve the thermo-physical properties of final products. The upscaling of such materials has not yet been achieved, as traditional onsite mixing and casting processes could damage the capsule, leading to a leakage of the active content and then a deterioration of the final element. The aim of this paper is to evaluate the influence of selectively depositing a layer of PCM on plaster, through a powder bed 3D printing process, on its density and thermal conductivity. A home-made selective-binding 3D printer has been used to assess samples of composites of calcium sulfate and encapsulated PCM. Thermal conductivity and Scanning Electron Microscope measurements were carried out on pure calcium sulfate as well as on a mix design containing a 5% mass ratio of PCM. The SEM measurements highlight that the PCM shells are undamaged by the selective-binding 3D printing process compared to the traditional mixing and casting process. Also, the 3D-printed composite material demonstrates a thermal conductivity reduction of 39%, which is linked to the 17% decrease in density. This applicative study validates the idea of designing functionally composite construction materials with phase change materials inserted as a thin layer between printed plaster layers and also demonstrates the great potential of this innovative selective-binding 3D printing technique. Full article
(This article belongs to the Section Additive Manufacturing Technologies)
Show Figures

Figure 1

47 pages, 3462 KB  
Review
Hydrogels and Nanogels: Pioneering the Future of Advanced Drug Delivery Systems
by Ernesto J. Delgado-Pujol, Guillermo Martínez, David Casado-Jurado, Juan Vázquez, Jesús León-Barberena, David Rodríguez-Lucena, Yadir Torres, Ana Alcudia and Belén Begines
Pharmaceutics 2025, 17(2), 215; https://doi.org/10.3390/pharmaceutics17020215 - 7 Feb 2025
Cited by 45 | Viewed by 6005
Abstract
Conventional drug delivery approaches, including tablets and capsules, often suffer from reduced therapeutic effectiveness, largely attributed to inadequate bioavailability and difficulties in ensuring patient adherence. These challenges have driven the development of advanced drug delivery systems (DDS), with hydrogels and especially nanogels emerging [...] Read more.
Conventional drug delivery approaches, including tablets and capsules, often suffer from reduced therapeutic effectiveness, largely attributed to inadequate bioavailability and difficulties in ensuring patient adherence. These challenges have driven the development of advanced drug delivery systems (DDS), with hydrogels and especially nanogels emerging as promising materials to overcome these limitations. Hydrogels, with their biocompatibility, high water content, and stimuli-responsive properties, provide controlled and targeted drug release. This review explores the evolution, properties, and classifications of hydrogels versus nanogels and their applications in drug delivery, detailing synthesis methods, including chemical crosslinking, physical self-assembly, and advanced techniques such as microfluidics and 3D printing. It also examines drug-loading mechanisms (e.g., physical encapsulation and electrostatic interactions) and release strategies (e.g., diffusion, stimuli-responsive, and enzyme-triggered). These gels demonstrate significant advantages in addressing the limitations of traditional DDS, offering improved drug stability, sustained release, and high specificity. Their adaptability extends to various routes of administration, including topical, oral, and injectable forms, while emerging nanogels further enhance therapeutic targeting through nanoscale precision and stimuli responsiveness. Although hydrogels and nanogels have transformative potential in personalized medicine, challenges remain in scalable manufacturing, regulatory approval, and targeted delivery. Future strategies include integrating biosensors for real-time monitoring, developing dual-stimuli-responsive systems, and optimizing surface functionalization for specificity. These advancements aim to establish hydrogels and nanogels as cornerstones of next-generation therapeutic solutions, revolutionizing drug delivery, and paving the way for innovative, patient-centered treatments. Full article
(This article belongs to the Section Drug Delivery and Controlled Release)
Show Figures

Graphical abstract

21 pages, 73296 KB  
Article
Experimental Research on the Tribological Behavior of Plastic Materials with Friction Properties, with Applications to Manipulators in the Pharmaceutical Industry
by Maria Stoica, Marius Gabriel Petrescu, Razvan George Ripeanu, Eugen Laudacescu and Maria Tănase
Coatings 2025, 15(1), 84; https://doi.org/10.3390/coatings15010084 - 14 Jan 2025
Cited by 1 | Viewed by 1209
Abstract
In this article, the authors present the results obtained within a complex experimental program that focuses on determining the tribological characteristics of the friction materials used in transmission belts, which are critical active components in manipulators within the pharmaceutical industry. The elements of [...] Read more.
In this article, the authors present the results obtained within a complex experimental program that focuses on determining the tribological characteristics of the friction materials used in transmission belts, which are critical active components in manipulators within the pharmaceutical industry. The elements of transmission belts, having the role of ensuring the movement of cardboard packaging—used when packing the foils with medicine capsules—and stopping them during the insertion of the foils, were studied. This repetitive cycle—travel-braking—leads to the wearing of the friction material on the active surface of the belt. The experiments were carried out in a dry environment (air) by testing different types of friction materials (original belt, 3D printed TPU 60A, and TPU 95A). While the study is limited to these three materials, the results highlight the significant influence of material type and infill percentage on the coefficient of friction (COF) and wear resistance. TPU 60A achieved the highest COF at 100% infill, indicating a superior grip but experienced substantial wear, under the same conditions. Conversely, TPU 95A demonstrated a lower COF, suggesting reduced grip, but exhibited exceptional wear resistance. The aim of the research is to provide a preliminary investigation into the materials’ wear resistance and braking effectiveness. The experiments utilized appropriate samples to replicate real operational conditions, particularly focusing on the nature of contact between the moving belt and the packaging. Full article
(This article belongs to the Special Issue Friction and Wear Behaviors in Mechanical Engineering)
Show Figures

Figure 1

15 pages, 3552 KB  
Article
Multifunctional 3D-Printed Thermoplastic Polyurethane (TPU)/Multiwalled Carbon Nanotube (MWCNT) Nanocomposites for Thermal Management Applications
by Daniele Rigotti, Andrea Dorigato and Alessandro Pegoretti
Appl. Sci. 2024, 14(20), 9614; https://doi.org/10.3390/app14209614 - 21 Oct 2024
Cited by 4 | Viewed by 3395
Abstract
In this work, multiwalled carbon nanotubes (MWCNTs) were melt-compounded into a novel thermal energy storage system consisting of a microencapsulated paraffin, with a melting temperature of 6 °C (M6D), dispersed within a flexible thermoplastic polyurethane (TPU) matrix. The resulting materials were then processed [...] Read more.
In this work, multiwalled carbon nanotubes (MWCNTs) were melt-compounded into a novel thermal energy storage system consisting of a microencapsulated paraffin, with a melting temperature of 6 °C (M6D), dispersed within a flexible thermoplastic polyurethane (TPU) matrix. The resulting materials were then processed via Fused Filament Fabrication (FFF), and their thermo-mechanical properties were comprehensively evaluated. After an optimization of the processing parameters, good adhesion between the polymeric layers was obtained. Field-Emission Scanning Electron Microscopy (FESEM) images of the 3D-printed samples highlighted a uniform distribution of the microcapsules within the polymer matrix, without an evident MWCNT agglomeration. The thermal energy storage/release capability provided by the paraffin microcapsules, evaluated through Differential Scanning Calorimetry (DSC), was slightly lowered by the FFF process but remained at an acceptable level (i.e., >80% with respect to the neat M6D capsules). The novelty of this work lies in the successful integration of MWCNTs and PCMs into a TPU matrix, followed by 3D printing via FFF technology. This approach combines the high thermal conductivity of MWCNTs with the thermal energy storage capabilities of PCMs, creating a multifunctional nanocomposite material with unique thermal management properties. Full article
(This article belongs to the Section Materials Science and Engineering)
Show Figures

Figure 1

14 pages, 3454 KB  
Review
Driving Deployment of Bioengineered Products—An Arduous, Sometimes Tedious, Challenging, Rewarding, Most Exciting Journey That Has to Be Made!
by Gordon George Wallace
Bioengineering 2024, 11(8), 856; https://doi.org/10.3390/bioengineering11080856 - 22 Aug 2024
Cited by 1 | Viewed by 1671
Abstract
More than three decades ago, we embarked on a number of bioengineering explorations using the most advanced materials and fabrication methods. In every area we ventured into, it was our intention to ensure fundamental discoveries were deployed into the clinic to benefit patients. [...] Read more.
More than three decades ago, we embarked on a number of bioengineering explorations using the most advanced materials and fabrication methods. In every area we ventured into, it was our intention to ensure fundamental discoveries were deployed into the clinic to benefit patients. When we embarked on this journey, we did so without a road map, not even a compass, and so the path was arduous, sometimes tedious. Now, we can see the doorway to deployment on the near horizon. We now appreciate that overcoming the challenges has made this a rewarding and exciting journey. However, maybe we could have been here a lot sooner, and so maybe the lessons we have learned could benefit others and accelerate progress in clinical translation. Through a number of case studies, including neural regeneration, cartilage regeneration, skin regeneration, the 3D printing of capsules for islet cell transplantation, and the bioengineered cornea, here, we retrace our steps. We will summarise the journey to date, point out the obstacles encountered, and celebrate the translational impact. Then, we will provide a framework for project design with the clinical deployment of bioengineered products as the goal. Full article
(This article belongs to the Special Issue 10th Anniversary of Bioengineering: Perspectives in Bioengineering)
Show Figures

Figure 1

15 pages, 4188 KB  
Article
Three-Dimensional Printing of PVA Capsular Devices for Applications in Compounding Pharmacy: Effect of Design Parameters on Pharmaceutical Performance
by Juan Francisco Peña, Ivana Cotabarren and Loreana Gallo
Pharmaceutics 2024, 16(8), 1069; https://doi.org/10.3390/pharmaceutics16081069 - 15 Aug 2024
Cited by 1 | Viewed by 1571
Abstract
The creation of products with personalized or innovative features in the pharmaceutical sector by using innovative technologies such as three-dimensional (3D) printing is particularly noteworthy, especially in the realm of compounding pharmacies. In this work, 3D printed capsule devices (CDs) with different wall [...] Read more.
The creation of products with personalized or innovative features in the pharmaceutical sector by using innovative technologies such as three-dimensional (3D) printing is particularly noteworthy, especially in the realm of compounding pharmacies. In this work, 3D printed capsule devices (CDs) with different wall thicknesses (0.2, 0.3, 0.4, 0.6, and 0.9 mm) and sizes were designed and successfully fabricated varying printing parameters such as extrusion temperature, printing speed, material flow percent, and nozzle diameter. The physicochemical, pharmaceutical, and biopharmaceutical performance of these CDs was evaluated with the aim of achieving an immediate drug release profile comparable to hard gelatin capsules (HGC) for use in magistral compounding. It was observed that the disintegration time of the CDs increased with wall thickness, which correlated with a slower drug release rate. CDs with configurations presenting 0.4 mm wall thickness and sizes comparable to HGC n° 0, 1, and 2 demonstrated satisfactory weight uniformity, short disintegration times, and immediate drug release, indicating their potential as effective devices in future compounding pharmacy applications. In addition, a modified Weibull-type model was proposed that incorporates wall thickness as a new variable in predicting dissolution profiles. This model improves the process of selecting a specific wall thickness to achieve the desired dissolution rate within a specified time frame. Full article
(This article belongs to the Special Issue 3D Printing of Drug Delivery Systems)
Show Figures

Graphical abstract

23 pages, 9762 KB  
Article
Virtually Possible: Enhancing Quality Control of 3D-Printed Medicines with Machine Vision Trained on Photorealistic Images
by Siyuan Sun, Manal E. Alkahtani, Simon Gaisford, Abdul W. Basit, Moe Elbadawi and Mine Orlu
Pharmaceutics 2023, 15(11), 2630; https://doi.org/10.3390/pharmaceutics15112630 - 16 Nov 2023
Cited by 9 | Viewed by 3132
Abstract
Three-dimensional (3D) printing is an advanced pharmaceutical manufacturing technology, and concerted efforts are underway to establish its applicability to various industries. However, for any technology to achieve widespread adoption, robustness and reliability are critical factors. Machine vision (MV), a subset of artificial intelligence [...] Read more.
Three-dimensional (3D) printing is an advanced pharmaceutical manufacturing technology, and concerted efforts are underway to establish its applicability to various industries. However, for any technology to achieve widespread adoption, robustness and reliability are critical factors. Machine vision (MV), a subset of artificial intelligence (AI), has emerged as a powerful tool to replace human inspection with unprecedented speed and accuracy. Previous studies have demonstrated the potential of MV in pharmaceutical processes. However, training models using real images proves to be both costly and time consuming. In this study, we present an alternative approach, where synthetic images were used to train models to classify the quality of dosage forms. We generated 200 photorealistic virtual images that replicated 3D-printed dosage forms, where seven machine learning techniques (MLTs) were used to perform image classification. By exploring various MV pipelines, including image resizing and transformation, we achieved remarkable classification accuracies of 80.8%, 74.3%, and 75.5% for capsules, tablets, and films, respectively, for classifying stereolithography (SLA)-printed dosage forms. Additionally, we subjected the MLTs to rigorous stress tests, evaluating their scalability to classify over 3000 images and their ability to handle irrelevant images, where accuracies of 66.5% (capsules), 72.0% (tablets), and 70.9% (films) were obtained. Moreover, model confidence was also measured, and Brier scores ranged from 0.20 to 0.40. Our results demonstrate promising proof of concept that virtual images exhibit great potential for image classification of SLA-printed dosage forms. By using photorealistic virtual images, which are faster and cheaper to generate, we pave the way for accelerated, reliable, and sustainable AI model development to enhance the quality control of 3D-printed medicines. Full article
(This article belongs to the Section Pharmaceutical Technology, Manufacturing and Devices)
Show Figures

Figure 1

17 pages, 1294 KB  
Article
Concrete Self-Healing for Sustainable Buildings: A Focus on the Economic Evaluation from a Life-Cycle Perspective
by Andres Miguel Panza Uguzzoni, Elena Fregonara, Diego Giuseppe Ferrando, Giovanni Anglani, Paola Antonaci and Jean-Marc Tulliani
Sustainability 2023, 15(18), 13637; https://doi.org/10.3390/su151813637 - 12 Sep 2023
Cited by 18 | Viewed by 7440
Abstract
Concrete is one of the world’s most used and produced materials, based on its dominant role in the construction sector, both for the construction of new structures and for the repair, restoration, and retrofitting of built ones. Recently, research has been focused on [...] Read more.
Concrete is one of the world’s most used and produced materials, based on its dominant role in the construction sector, both for the construction of new structures and for the repair, restoration, and retrofitting of built ones. Recently, research has been focused on the development of innovative solutions to extend the service life of reinforced concrete structures, specifically by introducing self-healing properties aimed at reducing the necessary maintenance interventions and, consequently, the environmental impacts. These solutions imply costs and financial feasibility impacts, which must be measured and evaluated to support the ranking of preferable alternatives. Thus, this paper proposes a methodology capable of supporting the selection of material/product options from the early design stages in the construction sector. Assuming a life-cycle perspective, the Life-Cycle Costing (LCC) approach is proposed for comparing three material solutions applied to the case study of a wall component hypothesized to be used in building construction in Turin, Northern Italy. Namely, traditional standard concrete and two different self-healing concrete types were evaluated using the Global Cost calculation of each solution. The focus is on the material service life as a crucial factor, capable of orienting investment decisions given its effects on the required maintenance activities (and related investments) and the obtainable residual value. Thus, according to a performance approach, LCC is combined with the Factor Method (FM). Assuming the capability of the lifespan to affect the Global Cost calculation, the results give full evidence of the potential benefits due to the use of self-healing materials in construction in terms of the reduction in maintenance costs, the increase in the durability of buildings and structures and related residual values, and consequently, the reduction in the environmental impacts. Full article
Show Figures

Figure 1

13 pages, 4815 KB  
Article
An Osteocartilaginous 3D Printing Implant Using a Biocompatible Polymer and Pre-Differentiated Mesenchymal Stem Cells in Sheep
by Carlos Landa-Solís, Clemente Ibarra, Andrea Salinas-Rojas, Carmina Ortega-Sánchez, Alexandra Berenice Luna-Angulo, María del Rocío Aguilar-Gaytán and Eric Joseph Hazan-Lasri
Appl. Sci. 2023, 13(18), 10177; https://doi.org/10.3390/app131810177 - 10 Sep 2023
Cited by 1 | Viewed by 1883
Abstract
(1) Background: Currently, there are no pharmacological treatments that can modify the course of osteoarthritis (OA). For this reason, the present work is focused on generating knowledge for the development of new therapeutic alternatives for the treatment of OA. The objective of this [...] Read more.
(1) Background: Currently, there are no pharmacological treatments that can modify the course of osteoarthritis (OA). For this reason, the present work is focused on generating knowledge for the development of new therapeutic alternatives for the treatment of OA. The objective of this work was to develop an articular hybrid implant with mesenchymal stem cells (MSCs) from sheep. The cells were differentiated into cartilage and bone using a bioabsorbable polymer with 3D printing Technology. (2) Methods: MSCs pre-differentiated to chondrocytes and osteoblasts were seeded on the 3D-printed scaffolds using polylactic acid (PLA). These were later implanted for 3 months in the thoracic ribs area and for 6 months inside the femoral head and outside of the joint capsule. After recovery, we analyzed the expressions of specific markers for bone and cartilage in the implants (3) Results: After 3 months, in lateral implants, the expression for bone markers (OPN, RUNX2) was similar to that of the control; at 6 months, we obtained a higher expression of bone markers in the implants with pre-differentiated MCS to osteoblasts outside and inside the joint. For cartilage markers, three months after the placement of the lateral implant, the expressions of Aggrecan and SOX9 COL2A1 were similar to those of the control, but the expression of COL2A1 was less; at 6 months, the three cartilage markers SOX9, Aggrecan, and COL2A1 showed significant expressions in the implant inside joint with pre-differentiated MCS to chondrocytes. (4) Conclusions: In this study, we demonstrated that the presence of pre-differentiated MSCs in the implants was a determinant factor for the expression of bone- and cartilage-specific markers at three and six months. We managed to generate a practical and easy-to-implement articular surface repair model. Full article
(This article belongs to the Special Issue Computer-Assisted Methods and 3D Printing in Orthopedics)
Show Figures

Figure 1

12 pages, 6014 KB  
Article
Development of 3D-Printed Self-Healing Capsules with a Separate Membrane and Investigation of Mechanical Properties for Improving Fracture Strength
by Taeuk Lim, Hao Cheng, Jie Hu, Yeongjun Lee, Sangyou Kim, Jangheon Kim and Wonsuk Jung
Materials 2023, 16(16), 5687; https://doi.org/10.3390/ma16165687 - 18 Aug 2023
Cited by 4 | Viewed by 1815
Abstract
Studies on self-healing capsules embedded in cement composites to heal such cracks have recently been actively researched in order to improve the dimensional stability of concrete structures. In particular, capsule studies were mainly conducted to separately inject reactive healing solutions into different capsules. [...] Read more.
Studies on self-healing capsules embedded in cement composites to heal such cracks have recently been actively researched in order to improve the dimensional stability of concrete structures. In particular, capsule studies were mainly conducted to separately inject reactive healing solutions into different capsules. However, with this method, there is an important limitation in that the probability of self-healing is greatly reduced because the two healing solutions must meet and react. Therefore, we propose three-dimensional (3D) printer-based self-healing capsules with a membrane structure that allows two healing solutions to be injected into one capsule. Among many 3D printing methods, we used the fusion deposition modeling (FDM) to design, analyze, and produce new self-healing capsules, which are widely used due to their low cost, precise manufacturing, and high-speed. However, polylactic lactic acid (PLA) extruded in the FDM has low adhesion energy between stacked layers, which causes different fracture strengths depending on the direction of the applied load and the subsequent performance degradation of the capsule. Therefore, the isotropic fracture characteristics of the newly proposed four types of separated membrane capsules were analyzed using finite element method analysis. Additionally, capsules were produced using the FDM method, and the compression test was conducted by applying force in the x, y, and z directions. The isotropic fracture strength was also analyzed using the relative standard deviation (RSD) parameter. As a result, the proposed separated membrane capsule showed that the RSD of isotropic fracture strength over all directions fell to about 18% compared to other capsules. Full article
(This article belongs to the Section Construction and Building Materials)
Show Figures

Figure 1

19 pages, 6084 KB  
Article
Analysis of the Self-Healing Capability of Thermoplastic Elastomer Capsules in a Polymeric Beam Structure Based on Strain Energy Release Behaviour during Crack Growth
by Mohammed Dukhi Almutairi, Feiyang He, Yousef Lafi Alshammari, Sultan Saleh Alnahdi and Muhammad Ali Khan
Polymers 2023, 15(16), 3384; https://doi.org/10.3390/polym15163384 - 12 Aug 2023
Cited by 3 | Viewed by 1909
Abstract
The objective of this study was to investigate the elastic and plastic responses of 3D-printed thermoplastic elastomer (TPE) beams under various bending loads. The study also aimed to develop a self-healing mechanism using origami TPE capsules embedded within an ABS structure. These cross-shaped [...] Read more.
The objective of this study was to investigate the elastic and plastic responses of 3D-printed thermoplastic elastomer (TPE) beams under various bending loads. The study also aimed to develop a self-healing mechanism using origami TPE capsules embedded within an ABS structure. These cross-shaped capsules have the ability to be either folded or elastically deformed. When a crack occurs in the ABS structure, the strain is released, causing the TPE capsule to unfold along the crack direction, thereby enhancing the crack resistance of the ABS structure. The enhanced ability to resist cracks was confirmed through a delamination test on a double cantilever specimen subjected to quasi-static load conditions. Consistent test outcomes highlighted how the self-healing process influenced the development of structural cracks. These results indicate that the suggested self-healing mechanism has the potential to be a unique addition to current methods, which mostly rely on external healing agents. Full article
(This article belongs to the Special Issue Applications of 3D Printing for Polymers 2.0)
Show Figures

Figure 1

7 pages, 952 KB  
Brief Report
Challenges of 3D Surface Reconstruction in Capsule Endoscopy
by Olivier Rukundo
J. Clin. Med. 2023, 12(15), 4955; https://doi.org/10.3390/jcm12154955 - 27 Jul 2023
Cited by 3 | Viewed by 2311
Abstract
Essential for improving the accuracy and reliability of bowel cancer screening, three-dimensional (3D) surface reconstruction using capsule endoscopy (CE) images remains challenging due to CE hardware and software limitations. This report generally focuses on challenges associated with 3D visualization and specifically investigates the [...] Read more.
Essential for improving the accuracy and reliability of bowel cancer screening, three-dimensional (3D) surface reconstruction using capsule endoscopy (CE) images remains challenging due to CE hardware and software limitations. This report generally focuses on challenges associated with 3D visualization and specifically investigates the impact of the indeterminate selection of the angle of the line–of–sight on 3D surfaces. Furthermore, it demonstrates that impact through 3D surfaces viewed at the same azimuth angles and different elevation angles of the line–of–sight. The report concludes that 3D printing of reconstructed 3D surfaces can potentially overcome line–of–sight indeterminate selection and 2D screen visual restriction-related errors. Full article
Show Figures

Figure 1

Back to TopTop