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3D Printing in Medicine and Biomedical Engineering
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3D Printing in Medicine and Biomedical Engineering

A topical collection in Materials (ISSN 1996-1944). This collection belongs to the section "Biomaterials".

Viewed by 98989

Editor

Dr. Filip Górski

E-Mail Website
Collection Editor
Faculty of Mechanical Engineering and Management, Poznan University of Technology, 60-965 Poznań, Poland
Interests: CAD/CAM/CAE systems; reverse engineering; 3D printing; virtual reality
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

Medicine and biomedical engineering are today among the most vital applications of 3D printing, also known as additive manufacturing (AM). Both doctors and patients, as well as scientists can benefit from recent advancements in this technology and its increasing availability at acceptable cost. Additive manufacturing of polymers, metals, and composites is invaluable to making customized implants, orthopedic and prosthetic supplies, pre- and mid-surgery supplies, and a number of other medical and biomedical devices, as well as training and educational models for students. Bioprinting allows the building of complex structures using living cells of various types.

However, many aspects of 3D printing in medicine and biomedical engineering remain unknown and need thorough studies in order to make progress, especially considering the whole process of making medical products—starting from obtaining patients’ data via medical imaging through data processing, design of products, selecting or often designing new materials, preparing and organizing manufacturing processes, and tuning them to obtain products fulfilling often strict requirements of strength, accuracy, surface quality, and chemical and biological reactivity. Therefore, this Topical Collection is dedicated to research and review papers tackling the problems of using additive technologies for medical and biomedical engineering applications.

Possible topics for this Topical Collection include, but are not limited to, the following:

  • 3D printing for making customized implants;
  • 3D-printed orthopedic and prosthetic supplies and studies on them;
  • 3D-printed pre- and mid-surgery supplies;
  • 3D-printed medical devices;
  • Bioprinting of tissues and organs;
  • Preparing 3D printing processes for medicine—studies on the influence of process parameters on the properties of obtained products;
  • New materials for 3D printing in medicine and biomedical engineering—design and studies of mechanical, chemical, and biological properties;
  • Medical imaging—MRI, CT, ultrasound, optical and laser scanning, and data processing for the preparation of 3D printing processes; and
  • Numerical simulation of 3D-printed structures used in medicine.

Dr. Filip Górski
Collection Editor

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Published Papers (32 papers)

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2024

Jump to: 2023, 2022, 2021, 2020

24 pages, 8652 KiB  
Article
Influence of Different Powder Conditioning Strategies on Metal Binder Jetting with Ti-6Al-4V
by Kevin Janzen, Kim Julia Kallies, Lennart Waalkes, Philipp Imgrund and Claus Emmelmann
Materials 2024, 17(3), 750; https://doi.org/10.3390/ma17030750 - 04 Feb 2024
Viewed by 850
Abstract
Metal binder jetting shows great potential for medical technology. This potential can be exploited by integrating binder jetting into existing process routes known from metal injection molding. The biggest challenge here is the flowability and packing behavior of the powders used, due to [...] Read more.
Metal binder jetting shows great potential for medical technology. This potential can be exploited by integrating binder jetting into existing process routes known from metal injection molding. The biggest challenge here is the flowability and packing behavior of the powders used, due to their low size distributions. This paper investigates different powder-drying strategies to improve flowability using a statistical experimental design. Because of its relevance for medical applications, spherical Ti-6Al-4V powder with a size distribution under 25 µm is dried under various parameters using vacuum and gas purging. The investigated parameters, time and temperature, are selected in a central-composite-circumscribed test plan with eleven tests and three center points. The target parameters—water content, flowability and impurity levels (oxygen, nitrogen)—of the powder are analyzed. For validation, practical test trials are carried out on an industrial binder jetting system with unconditioned powder and conditioning with optimized parameters, comparing the manufactured parts and the powder bed. An optimized drying cycle with a duration of 6 h at 200 °C was determined for the investigated powder. Significant improvements in the dimensional accuracy (from ±1.5 to 0.3%) of the components and the visual impression of the powder bed are demonstrated. Full article
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2023

Jump to: 2024, 2022, 2021, 2020

24 pages, 2065 KiB  
Review
Drug-Eluting Sutures by Hot-Melt Extrusion: Current Trends and Future Potentials
by Garba M. Khalid and Nashiru Billa
Materials 2023, 16(22), 7245; https://doi.org/10.3390/ma16227245 - 20 Nov 2023
Cited by 1 | Viewed by 1067
Abstract
Surgical site infections (SSIs) may result from surgical procedures requiring a secondary administration of drugs at site or systemically in treating the infection. Drug-eluting sutures containing antimicrobial agents symbolise a latent strategy that precludes a secondary drug administration. It also offers the possibility [...] Read more.
Surgical site infections (SSIs) may result from surgical procedures requiring a secondary administration of drugs at site or systemically in treating the infection. Drug-eluting sutures containing antimicrobial agents symbolise a latent strategy that precludes a secondary drug administration. It also offers the possibility of delivering a myriad of therapeutic agents to a localised wound site to effect analgesia, anti-inflammation, or the deployment of proteins useful for wound healing. Further, the use of biodegradable drug-eluting sutures eliminates the need for implanting foreign material into the wound, which needs to be removed after healing. In this review, we expound on recent trends in the manufacture of drug-eluting sutures with a focus on the hot-melt extrusion (HME) technique. HME provides a solvent-free, continuous one-step manufacturing conduit for drug-eluting sutures, hence, there is no drying step, which can be detrimental to the drug or suture threads and, thus, environmentally friendly. There is the possibility of combining the technology with additive manufacturing platforms to generate personalised drug-loaded implantable devices through prototyping and scalability. The review also highlights key material requirements for fabricating drug-eluting sutures by HME, as well as quality attributes. Finally, a preview of emerging drug-eluting sutures and advocacy for harmonisation of quality assurance by regulatory authorities that permits quality evaluation of novelty sutures is presented. Full article
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12 pages, 3471 KiB  
Article
In Vitro Comparison of Internal and Marginal Adaptation between Printed and Milled Onlays
by Oriol Cantó-Navés, Kyra Michels, Oscar Figueras-Alvarez, Sandra Fernández-Villar, Josep Cabratosa-Termes and Miguel Roig
Materials 2023, 16(21), 6962; https://doi.org/10.3390/ma16216962 - 30 Oct 2023
Cited by 2 | Viewed by 885
Abstract
Statement of problem: Nowadays, milling is still the gold standard for fabricating indirect restorations, but to overcome its disadvantages, there are alternatives, such as 3D printing. Purpose: This study aimed to compare the gaps between the prepared tooth and milled and printed onlays [...] Read more.
Statement of problem: Nowadays, milling is still the gold standard for fabricating indirect restorations, but to overcome its disadvantages, there are alternatives, such as 3D printing. Purpose: This study aimed to compare the gaps between the prepared tooth and milled and printed onlays fabricated with the same CAD design. It also aimed to determine the gap reproducibility across onlays fabricated by 3D printing and milling. Methods: A resin tooth was prepared for an onlay. After scanning the preparation, an onlay was designed with proprietary dental software. Next, 22 onlays were milled in a graphene-reinforced PMMA disc (Group 1), and 22 onlays were 3D-printed with a hybrid composite material (Group 2). After that, all fabricated restorations were scanned and superimposed on the scanned prepared resin tooth. Subsequently, a specific software was used to measure the margin, central, and intaglio-located gap between the milled or printed restoration and the preparation. Finally, measurements were compared with a multifactor analysis of variance. Results: The results demonstrated that printed onlays (Group 2) adapted better to the prepared tooth than the milled ones (Group 1) (p < 0.05). The comparison of standard deviations showed the better gap reproducibility of printed onlays (p < 0.05). Conclusion: This study concluded that the printed onlays adapted significantly better to the prepared tooth than the milled onlays. Printed onlays also showed significantly better gap reproducibility. Full article
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13 pages, 1278 KiB  
Article
Additive Manufacturing of an Extended-Release Tablet of Tacrolimus
by Azin Abdollahi, Zahra Ansari, Mohammad Akrami, Ismaeil Haririan, Simin Dashti-Khavidaki, Mohammad Irani, Mojtaba Kamankesh and Emad Ghobadi
Materials 2023, 16(14), 4927; https://doi.org/10.3390/ma16144927 - 10 Jul 2023
Cited by 7 | Viewed by 1423
Abstract
An extended-release tablet of tacrolimus as once-daily dosing was fabricated using 3D printing technology. It was developed by combining two 3D-printing methods in parallel. Indeed, an optimized mixture of PVA, sorbitol, and magnesium stearate as a shell compartment was printed through a hot-melt [...] Read more.
An extended-release tablet of tacrolimus as once-daily dosing was fabricated using 3D printing technology. It was developed by combining two 3D-printing methods in parallel. Indeed, an optimized mixture of PVA, sorbitol, and magnesium stearate as a shell compartment was printed through a hot-melt extrusion (HME) nozzle while an HPMC gel mixture of the drug in the core compartment was printed by a pressure-assisted micro-syringe (PAM). A 3D-printed tablet with an infill of 90% was selected as an optimized formula upon the desired dissolution profile, releasing 86% of the drug at 12 h, similar to the commercial one. The weight variation, friability, hardness, assay, and content uniformity determination met USP requirements. A microbial evaluation showed that the 3D-printed tablet does not support microbial growth. SEM analysis showed smooth surfaces with multiple deposited layers. No peak interference appeared based on FTIR analysis. No decomposition of the polymer and drug was observed in the printing temperature, and no change in tacrolimus crystallinity was detected based on TGA and DSC analyses, respectively. The novel, sTable 3D-printed tablet, fabricated using controllable additive manufacturing, can quickly provide tailored dosing with specific kinetic release for personalized medicine at the point-of-care. Full article
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19 pages, 9925 KiB  
Article
Exploring High-Precision Non-Assembly Mechanisms: Design of a Vitrectome Mechanism for Eye Surgery
by Kirsten Lussenburg, Marta Scali, Maarten Stolk, Daisy Robijns, Aimée Sakes and Paul Breedveld
Materials 2023, 16(5), 1772; https://doi.org/10.3390/ma16051772 - 21 Feb 2023
Viewed by 1642
Abstract
A vitrectome is a commonly used instrument in eye surgery, which is used to cut and aspirate the vitreous body out of the eye. The mechanism of the vitrectome consists of miniature components that need to be assembled by hand due to their [...] Read more.
A vitrectome is a commonly used instrument in eye surgery, which is used to cut and aspirate the vitreous body out of the eye. The mechanism of the vitrectome consists of miniature components that need to be assembled by hand due to their size. Non-assembly 3D printing, in which fully functional mechanisms can be produced in a single production step, can help create a more streamlined production process. We propose a vitrectome design based on a dual-diaphragm mechanism, which can be produced with minimal assembly steps using PolyJet printing. Two different diaphragm designs were tested to fulfill the requirements of the mechanism: a homogenous design based on ‘digital’ materials and a design using an ortho-planar spring. Both designs were able to fulfill the required displacement for the mechanism of 0.8 mm, as well as cutting forces of at least 8 N. The requirements for the cutting speed of the mechanism of 8000 RPM were not fulfilled by both designs, since the viscoelastic nature of the PolyJet materials resulted in a slow response time. The proposed mechanism does show promise to be used in vitrectomy; however, we suggest that more research into different design directions is required. Full article
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9 pages, 2819 KiB  
Article
Particle Image Velocimetry of 3D-Printed Anatomical Blood Vascular Models Affected by Atherosclerosis
by Arkadiusz Antonowicz, Krzysztof Wojtas, Łukasz Makowski, Wojciech Orciuch and Michał Kozłowski
Materials 2023, 16(3), 1055; https://doi.org/10.3390/ma16031055 - 25 Jan 2023
Cited by 6 | Viewed by 1878
Abstract
Improvements in the diagnosis and treatment of cardiovascular diseases facilitate a better understanding of the ongoing process. The study of biomedical fluid dynamics using non-intrusive visualizing methods on a micro-scale has become possible using a proper 3D printing process. The computed tomography scan [...] Read more.
Improvements in the diagnosis and treatment of cardiovascular diseases facilitate a better understanding of the ongoing process. The study of biomedical fluid dynamics using non-intrusive visualizing methods on a micro-scale has become possible using a proper 3D printing process. The computed tomography scan of a patient with atherosclerosis was processed, and a 3D-printed artery with an inlet diameter of 4.2 mm was developed and measured using three different constant flow rates. To mimic blood, a solution of glycerin and water was used. The procedure to obtain a proper 3D-printed model using low-force stereolithography technology with high-quality optical access usable for PIV was described and discussed. The paper presents the results of PIV as multi-stitched, color-coded vector maps from the axis cross section along the whole 3D-printed model. The obtained data allowed a resolution of 100 × 100 µm per single vector to be achieved. Furthermore, the results of the stitched 16 base images of the artery and the 3D-printed model prepared were included. The results of this study show that 3D prints allow for the creation of the desired geometry and can be used to investigate severe pathologies of the human circulatory system. The strengths and weaknesses of this methodology were discussed and compared to other techniques used to obtain transparent objects. Full article
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24 pages, 2863 KiB  
Review
Additive Manufacturing of 3D Anatomical Models—Review of Processes, Materials and Applications
by Magdalena Żukowska, Maryam Alsadat Rad and Filip Górski
Materials 2023, 16(2), 880; https://doi.org/10.3390/ma16020880 - 16 Jan 2023
Cited by 9 | Viewed by 2533
Abstract
The methods of additive manufacturing of anatomical models are widely used in medical practice, including physician support, education and planning of treatment procedures. The aim of the review was to identify the area of additive manufacturing and the application of anatomical models, imitating [...] Read more.
The methods of additive manufacturing of anatomical models are widely used in medical practice, including physician support, education and planning of treatment procedures. The aim of the review was to identify the area of additive manufacturing and the application of anatomical models, imitating both soft and hard tissue. The paper outlines the most commonly used methodologies, from medical imaging to obtaining a functional physical model. The materials used to imitate specific organs and tissues, and the related technologies used to produce, them are included. The study covers publications in English, published by the end of 2022 and included in the Scopus. The obtained results emphasise the growing popularity of the issue, especially in the areas related to the attempt to imitate soft tissues with the use of low-cost 3D printing and plastic casting techniques. Full article
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2022

Jump to: 2024, 2023, 2021, 2020

14 pages, 18306 KiB  
Article
Improved Osseointegration of Selective Laser Melting Titanium Implants with Unique Dual Micro/Nano-Scale Surface Topography
by Xuetong Sun, Huaishu Lin, Chunyu Zhang, Ruiran Huang, Ying Liu, Gong Zhang and Si Di
Materials 2022, 15(21), 7811; https://doi.org/10.3390/ma15217811 - 05 Nov 2022
Cited by 2 | Viewed by 1450
Abstract
Selective laser melting manufacture of patient specific Ti implants is serving as a promising approach for bone tissue engineering. The success of implantation is governed by effective osseointegration, which depends on the surface properties of implants. To improve the bioactivity and osteogenesis, the [...] Read more.
Selective laser melting manufacture of patient specific Ti implants is serving as a promising approach for bone tissue engineering. The success of implantation is governed by effective osseointegration, which depends on the surface properties of implants. To improve the bioactivity and osteogenesis, the universal surface treatment for SLM-Ti implants is to remove the primitive roughness and then reengineer new roughness by various methods. In this study, the micro-sized partially melted Ti particles on the SLM-Ti surface were preserved for assembling mesoporous bioactive glass nanospheres to obtain a unique micro/nano- topography through combination of SLM manufacture and sol–gel processes. The results of simulated body fluid immersion test showed that bioactive ions (Ca, Si) can be continuously and stably released from the MBG nanospheres. The osseointegration properties of SLM-Ti samples, examined using pre-osteoblast cells, showed enhanced adhesion and osteogenic differentiation compared with commercial pure titanium commonly used as orthopedic implants. Overall, the developed approach of construction of the dual micro/nano topography generated on the SLM-Ti native surface could be critical to enhance musculoskeletal implant performance. Full article
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2 pages, 692 KiB  
Correction
Correction: Liu et al. 3D-Printed Double-Helical Biodegradable Iron Suture Anchor: A Rabbit Rotator Cuff Tear Model Materials 2022, 15, 2801
by Wen-Chih Liu, Chih-Hau Chang, Chung-Hwan Chen, Chun-Kuan Lu, Chun-Hsien Ma, Shin-I Huang, Wei-Lun Fan, Hsin-Hsin Shen, Pei-I Tsai, Kuo-Yi Yang and Yin-Chih Fu
Materials 2022, 15(20), 7226; https://doi.org/10.3390/ma15207226 - 17 Oct 2022
Viewed by 878
Abstract
In the original publication [...] Full article
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13 pages, 2605 KiB  
Article
Additive Manufacturing of Spinal Braces: Evaluation of Production Process and Postural Stability in Patients with Scoliosis
by Fabio Alexander Storm, Davide Felice Redaelli, Emilia Biffi, Gianluigi Reni and Paolo Fraschini
Materials 2022, 15(18), 6221; https://doi.org/10.3390/ma15186221 - 07 Sep 2022
Cited by 1 | Viewed by 2327
Abstract
Spinal orthoses produced using additive manufacturing show great potential for obtaining patient-specific solutions in clinical applications, reducing manual operations, time consumption, and material waste. This study was conducted to evaluate the production process of spinal orthoses produced by additive manufacturing, and to test [...] Read more.
Spinal orthoses produced using additive manufacturing show great potential for obtaining patient-specific solutions in clinical applications, reducing manual operations, time consumption, and material waste. This study was conducted to evaluate the production process of spinal orthoses produced by additive manufacturing, and to test the effects of 3D-printed braces on postural stability in patients with adolescent idiopathic scoliosis and osteogenesis imperfecta. Ten patients were recruited consecutively and were asked to wear a spinal orthosis produced by additive manufacturing for 2 weeks. The four phases of the production process for each brace were evaluated separately on a scale from 0 (not acceptable) to 3 (optimal). Postural stability in the unbraced and the two braced conditions (3D-printed and conventional) was assessed using validated metrics obtained from a wearable inertial sensor. The production process was evaluated as good in four cases, acceptable in five cases, and not acceptable in one case, due to problems in the printing phase. No statistically significant differences were observed in any of the postural balance metrics between the 3D-printed and conventional brace. On the other hand, postural balance metrics improved significantly with both types of braces with respect to the unbraced condition. Spinal orthoses produced with an innovative production process based on digital scans, CAD, and 3D printing are valid alternatives to conventionally produced orthoses, providing equivalent postural stability. Full article
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14 pages, 8503 KiB  
Article
Design of a Novel Trabecular Acetabular Cup and Selective Laser Melting Fabrication
by Congyu Wang, Baoyu Sun, Yongdi Zhang, Congwei Wang and Guang Yang
Materials 2022, 15(17), 6142; https://doi.org/10.3390/ma15176142 - 04 Sep 2022
Cited by 5 | Viewed by 2107
Abstract
The acetabular cups used in total hip arthroplasty are mostly made of dense metal materials with an elastic moduli much higher than that of human bone. This leads to stress shielding after implantation, which may cause aseptic loosening of the implant. Selective laser [...] Read more.
The acetabular cups used in total hip arthroplasty are mostly made of dense metal materials with an elastic moduli much higher than that of human bone. This leads to stress shielding after implantation, which may cause aseptic loosening of the implant. Selective laser melting (SLM) technology allows us to produce tiny and complex porous structures and to reduce the elastic moduli of dense metals, thereby avoiding stress shielding. In the present study, rhombic dodecahedron porous structures with cell sizes of 1 mm, 1.5 mm, and 2 mm were designed. The strut diameter was changed to ensure that the porosity and pore size would meet the bone ingrowth requirements. Then, porous Ti6Al4V alloy specimens were printed using SLM, and compressive tests were carried out. The results showed that the compressive strength and elastic modulus values of the specimens with a cell size of 1.5 mm were in the range of 78.16–242.94 MPa and 1.74–4.17 GPa, respectively, which are in line with the mechanical properties of human cortical bone. Finite element analysis of a total hip joint model was carried out to simulate gait, and the surface of the trabecular acetabular cup was divided into 10 regions according to the stress distribution, with the stress interval in the range of 37.44–219.24 MPa. According to the compression test results, the gradient structure of Ti6Al4V alloy with different porosity was designed for trabecular coating. The gradient porous structure meets the mechanical requirements and is closer to the natural structure of human bone than the uniformly distributed porous structure. Full article
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15 pages, 3878 KiB  
Article
Numerical and Experimental Mechanical Analysis of Additively Manufactured Ankle–Foot Orthoses
by Ratnesh Raj, Amit Rai Dixit, Krzysztof Łukaszewski, Radosław Wichniarek, Justyna Rybarczyk, Wiesław Kuczko and Filip Górski
Materials 2022, 15(17), 6130; https://doi.org/10.3390/ma15176130 - 03 Sep 2022
Cited by 14 | Viewed by 2444
Abstract
Growing age and different conditions often require the replacement of orthoses, and FDM-based 3D printing can produce them quickly with less investment. In today’s market for orthotics, these characteristics are highly desired. Therefore, this study is fully focused on the optimization and strength [...] Read more.
Growing age and different conditions often require the replacement of orthoses, and FDM-based 3D printing can produce them quickly with less investment. In today’s market for orthotics, these characteristics are highly desired. Therefore, this study is fully focused on the optimization and strength analysis of FDM 3D-printed ankle–foot orthoses (AFO) fabricated using PLA and PLA reinforced with carbon fiber (PLA-C). An increase in ankle plantar-flexor force can be achieved by reinforcing thermoplastic AFOs with CFs. Specially designed mechanical strength tests were conducted at the UTM to generate force–displacement curves for stored elastic energy and fracture studies. The mechanical behavior of both AFOs was predicted with the help of an FEA. The model predictions were validated by comparing them with mechanical strength testing conducted under the same loading and boundary conditions as the FEA. In both the prediction and experimental analysis, the PLA-C-based AFOs were stiffer and could withstand greater loads than the PLA-based AFOs. An area of high stress in the simulation and a fracture point in experimentation were both found at the same location. Furthermore, these highly accurate models will allow the fabrication of AFOs to be improved without investing time and resources on trials. Full article
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11 pages, 2833 KiB  
Article
Demonstration of Use of a Novel 3D Printed Simulator for Mitral Valve Transcatheter Edge-to-Edge Repair (TEER)
by Michele Bertolini, Michael Mullen, Georgios Belitsis, Angel Babu, Giorgio Colombo, Andrew Cook, Aigerim Mullen and Claudio Capelli
Materials 2022, 15(12), 4284; https://doi.org/10.3390/ma15124284 - 17 Jun 2022
Cited by 2 | Viewed by 2250
Abstract
Mitral regurgitation is a common valvular disorder. Transcatheter edge-to-edge repair (TEER) is a minimally invasive technique which involves holding together the middle segments of the mitral valve leaflets, thereby reducing regurgitation. To date, MitraClip™ is the only Food and Drug Administration (FDA)-approved device [...] Read more.
Mitral regurgitation is a common valvular disorder. Transcatheter edge-to-edge repair (TEER) is a minimally invasive technique which involves holding together the middle segments of the mitral valve leaflets, thereby reducing regurgitation. To date, MitraClip™ is the only Food and Drug Administration (FDA)-approved device for TEER. The MitraClip procedure is technically challenging, characterised by a steep learning curve. Training is generally performed on simplified models, which do not emphasise anatomical features, realistic materials, or procedural scenarios. The aim of this study is to propose a novel, 3D printed simulator, with a major focus on reproducing the anatomy and plasticity of all areas of the heart involved and specifically the ones of the mitral valve apparatus. A three-dimensional digital model of a heart was generated by segmenting computed tomography (CT). The model was subsequently modified for: (i) adding anatomical features not fully visible with CT; (ii) adapting the model to interact with the MitraClip procedural equipment; and (iii) ensuring modularity of the system. The model was manufactured with a Polyjet technology printer, with a differentiated material assignment among its portions. Polypropylene threads were stitched to replicate chordae tendineae. The proposed system was successfully tested with MitraClip equipment. The simulator was assessed to be feasible to practice in a realistic fashion, different procedural aspects including access, navigation, catheter steering, and leaflets grasping. In addition, the model was found to be compatible with clinical procedural imaging fluoroscopy equipment. Future studies will assess the effect of the proposed training system on improving TEER training. Full article
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11 pages, 1584 KiB  
Article
3D-Printed Patient-Specific Casts for the Distal Radius in Children: Outcome and Pre-Market Survey
by Simone Lazzeri, Emiliano Talanti, Simone Basciano, Raffaele Barbato, Federico Fontanelli, Francesca Uccheddu, Michaela Servi, Yary Volpe, Laura Vagnoli, Elena Amore, Antonio Marzola, Kathleen S. McGreevy and Monica Carfagni
Materials 2022, 15(8), 2863; https://doi.org/10.3390/ma15082863 - 13 Apr 2022
Cited by 3 | Viewed by 2069
Abstract
Background: Orthopaedic and Trauma surgery is expected to undergo profound transformation as a result of the adoption of 3D technology. Among the various applications, patient specific manufacturing of splints and casts would appear to be, particularly in children, an interesting implementation. This study [...] Read more.
Background: Orthopaedic and Trauma surgery is expected to undergo profound transformation as a result of the adoption of 3D technology. Among the various applications, patient specific manufacturing of splints and casts would appear to be, particularly in children, an interesting implementation. This study aims to assess the safety of patient specific 3D casts obtained with a newly developed 3D-scanning devise in a small case series. We therefore conducted a clinical outcome and pre-marketing study in 10 consecutive patients with distal radius fractures treated at an Academic Level I Pediatric Trauma Center. After the application of the 3D cast, patients underwent three consecutive evaluations in the following 21 days. The main outcome measurements were: pain, skin lesions and general comfort, and acceptance of the cast. The three domains were measured with the Visual Analogue Scale (VAS), the NPUAP/EPUAP classification and the Positive affect-Negative affect Scale for Children (PANAS-C), the Self-Assessment Manikin (SAM) clinical psychology tests and a Likert-type five item questionnaire, respectively. A final mechanical analysis of the cast was carried out to confirm product integrity. Results: The results obtained were consistently positive in the investigated domains of general comfort, efficacy of contention and mechanical integrity of the 3D-printed cast as well as in the practicability of the supply chain. Conclusions: This study provides Level IV evidence that patient specific 3D printed casts obtained with a specifically designed software were safe in the management of “buckle” fractures of the distal radius in children. These results encourage to extend the technology to the treatment of more demanding fractures. Full article
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18 pages, 5877 KiB  
Article
3D-Printed Double-Helical Biodegradable Iron Suture Anchor: A Rabbit Rotator Cuff Tear Model
by Wen-Chih Liu, Chih-Hau Chang, Chung-Hwan Chen, Chun-Kuan Lu, Chun-Hsien Ma, Shin-I Huang, Wei-Lun Fan, Hsin-Hsin Shen, Pei-I Tsai, Kuo-Yi Yang and Yin-Chih Fu
Materials 2022, 15(8), 2801; https://doi.org/10.3390/ma15082801 - 11 Apr 2022
Cited by 4 | Viewed by 3066 | Correction
Abstract
Suture anchors are extensively used in rotator cuff tear surgery. With the advancement of three-dimensional printing technology, biodegradable metal has been developed for orthopedic applications. This study adopted three-dimensional-printed biodegradable Fe suture anchors with double-helical threads and commercialized non-vented screw-type Ti suture anchors [...] Read more.
Suture anchors are extensively used in rotator cuff tear surgery. With the advancement of three-dimensional printing technology, biodegradable metal has been developed for orthopedic applications. This study adopted three-dimensional-printed biodegradable Fe suture anchors with double-helical threads and commercialized non-vented screw-type Ti suture anchors with a tapered tip in the experimental and control groups, respectively. The in vitro study showed that the Fe and Ti suture anchors exhibited a similar ultimate failure load in 20-pound-per-cubic-foot polyurethane foam blocks and rabbit bone. In static immersion tests, the corrosion rate of Fe suture anchors was 0.049 ± 0.002 mm/year. The in vivo study was performed on New Zealand white rabbits and SAs were employed to reattach the ruptured supraspinatus tendon. The in vivo ultimate failure load of the Fe suture anchors was superior to that of the Ti suture anchors at 6 weeks. Micro-computed tomography showed that the bone volume fraction and bone surface density in the Fe suture anchors group 2 and 6 weeks after surgery were superior, and the histology confirmed that the increased bone volume around the anchor was attributable to mineralized osteocytes. The three-dimensional-printed Fe suture anchors outperformed the currently used Ti suture anchors. Full article
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21 pages, 2379 KiB  
Review
Industry 4.0 and Digitalisation in Healthcare
by Vladimir V. Popov, Elena V. Kudryavtseva, Nirmal Kumar Katiyar, Andrei Shishkin, Stepan I. Stepanov and Saurav Goel
Materials 2022, 15(6), 2140; https://doi.org/10.3390/ma15062140 - 14 Mar 2022
Cited by 48 | Viewed by 8461
Abstract
Industry 4.0 in healthcare involves use of a wide range of modern technologies including digitisation, artificial intelligence, user response data (ergonomics), human psychology, the Internet of Things, machine learning, big data mining, and augmented reality to name a few. The healthcare industry is [...] Read more.
Industry 4.0 in healthcare involves use of a wide range of modern technologies including digitisation, artificial intelligence, user response data (ergonomics), human psychology, the Internet of Things, machine learning, big data mining, and augmented reality to name a few. The healthcare industry is undergoing a paradigm shift thanks to Industry 4.0, which provides better user comfort through proactive intervention in early detection and treatment of various diseases. The sector is now ready to make its next move towards Industry 5.0, but certain aspects that motivated this review paper need further consideration. As a fruitful outcome of this review, we surveyed modern trends in this arena of research and summarised the intricacies of new features to guide and prepare the sector for an Industry 5.0-ready healthcare system. Full article
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2021

Jump to: 2024, 2023, 2022, 2020

18 pages, 27869 KiB  
Article
A Fully 3D-Printed Steerable Instrument for Minimally Invasive Surgery
by Costanza Culmone, Kirsten Lussenburg, Joost Alkemade, Gerwin Smit, Aimée Sakes and Paul Breedveld
Materials 2021, 14(24), 7910; https://doi.org/10.3390/ma14247910 - 20 Dec 2021
Cited by 10 | Viewed by 5161
Abstract
In the field of medical instruments, additive manufacturing allows for a drastic reduction in the number of components while improving the functionalities of the final design. In addition, modifications for users’ needs or specific procedures become possible by enabling the production of single [...] Read more.
In the field of medical instruments, additive manufacturing allows for a drastic reduction in the number of components while improving the functionalities of the final design. In addition, modifications for users’ needs or specific procedures become possible by enabling the production of single customized items. In this work, we present the design of a new fully 3D-printed handheld steerable instrument for laparoscopic surgery, which was mechanically actuated using cables. The pistol-grip handle is based on ergonomic principles and allows for single-hand control of both grasping and omnidirectional steering, while compliant joints and snap-fit connectors enable fast assembly and minimal part count. Additive manufacturing allows for personalization of the handle to each surgeon’s needs by adjusting specific dimensions in the CAD model, which increases the user’s comfort during surgery. Testing showed that the forces on the instrument handle required for steering and grasping were below 15 N, while the grasping force efficiency was calculated to be 10–30%. The instrument combines the advantages of additive manufacturing with regard to personalization and simplified assembly, illustrating a new approach to the design of advanced surgical instruments where the customization for a single procedure or user’s need is a central aspect. Full article
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16 pages, 40792 KiB  
Article
A Three-Dimensional Printed Foot Orthosis for Flexible Flatfoot: An Exploratory Biomechanical Study on Arch Support Reinforcement and Undercut
by Ka-Wing Cheng, Yinghu Peng, Tony Lin-Wei Chen, Guoxin Zhang, James Chung-Wai Cheung, Wing-Kai Lam, Duo Wai-Chi Wong and Ming Zhang
Materials 2021, 14(18), 5297; https://doi.org/10.3390/ma14185297 - 14 Sep 2021
Cited by 12 | Viewed by 4088
Abstract
The advancement of 3D printing and scanning technology enables the digitalization and customization of foot orthosis with better accuracy. However, customized insoles require rectification to direct control and/or correct foot deformity, particularly flatfoot. In this exploratory study, we aimed at two design rectification [...] Read more.
The advancement of 3D printing and scanning technology enables the digitalization and customization of foot orthosis with better accuracy. However, customized insoles require rectification to direct control and/or correct foot deformity, particularly flatfoot. In this exploratory study, we aimed at two design rectification features (arch stiffness and arch height) using three sets of customized 3D-printed arch support insoles (R+U+, R+U−, and R−U+). The arch support stiffness could be with or without reinforcement (R+/−) and the arch height may or may not have an additional elevation, undercutting (U+/−), which were compared to the control (no insole). Ten collegiate participants (four males and six females) with flexible flatfoot were recruited for gait analysis on foot kinematics, vertical ground reaction force, and plantar pressure parameters. A randomized crossover trial was conducted on the four conditions and analyzed using the Friedman test with pairwise Wilcoxon signed-rank test. Compared to the control, there were significant increases in peak ankle dorsiflexion and peak pressure at the medial midfoot region, accompanied by a significant reduction in peak pressure at the hindfoot region for the insole conditions. In addition, the insoles tended to control hindfoot eversion and forefoot abduction though the effects were not significant. An insole with stronger support features (R+U+) did not necessarily produce more favorable outcomes, probably due to over-cutting or impingement. The outcome of this study provides additional data to assist the design rectification process. Future studies should consider a larger sample size with stratified flatfoot features and covariating ankle flexibility while incorporating more design features, particularly medial insole postings. Full article
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26 pages, 8122 KiB  
Article
Study on Properties of Automatically Designed 3D-Printed Customized Prosthetic Sockets
by Filip Górski, Radosław Wichniarek, Wiesław Kuczko and Magdalena Żukowska
Materials 2021, 14(18), 5240; https://doi.org/10.3390/ma14185240 - 12 Sep 2021
Cited by 14 | Viewed by 3474
Abstract
This paper presents the results of experiments conducted on a batch of additively manufactured customized prosthetic sockets for upper limbs, made of thermoplastics and designed automatically on the basis of a 3D-scanned limb of a 3-year-old patient. The aim of this work was [...] Read more.
This paper presents the results of experiments conducted on a batch of additively manufactured customized prosthetic sockets for upper limbs, made of thermoplastics and designed automatically on the basis of a 3D-scanned limb of a 3-year-old patient. The aim of this work was to compare sockets made of two different materials—rigid PLA and elastic TPE. Two distinct socket designs with various mounting systems were prepared. To find a reliable set of parameters for cheap and stable manufacturing of usable prostheses using 3D printers, realizing the fused deposition modeling (FDM) process, sets of sockets were manufactured with various process parameters. This paper presents the methodology of the design, the plan of the experiments and the obtained results in terms of process stability, fit and assessment by patient, as well as strength of the obtained sockets and their measured surface roughness. The results are promising, as most of the obtained products fulfil the strength criteria, although not all of them meet the fitting and use comfort criteria. As a result, recommendations of materials and process parameters were determined. These parameters were included in a prototype of the automated design and production system developed by the authors, and prostheses for several other patients were manufactured. Full article
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16 pages, 3542 KiB  
Article
Independent Lung Ventilation-Experimental Studies on a 3D Printed Respiratory Tract Model
by Katarzyna Kramek-Romanowska, Anna M. Stecka, Krzysztof Zieliński, Agata Dorosz, Piotr Okrzeja, Marcin Michnikowski and Marcin Odziomek
Materials 2021, 14(18), 5189; https://doi.org/10.3390/ma14185189 - 09 Sep 2021
Cited by 3 | Viewed by 2396
Abstract
Independent lung ventilation (ILV) is a life-saving procedure in unilateral pulmonary pathologies. ILV is underused in clinical practice, mostly due to the technically demanding placement of a double lumen endotracheal tube (ETT). Moreover, the determination of ventilation parameters for each lung in vivo [...] Read more.
Independent lung ventilation (ILV) is a life-saving procedure in unilateral pulmonary pathologies. ILV is underused in clinical practice, mostly due to the technically demanding placement of a double lumen endotracheal tube (ETT). Moreover, the determination of ventilation parameters for each lung in vivo is limited. In recent years, the development of 3D printing techniques enabled the production of highly accurate physical models of anatomical structures used for in vitro research, considering the high risk of in vivo studies. The purpose of this study was to assess the influence of double-lumen ETT on the gas transport and mixing in the anatomically accurate 3D-printed model of the bronchial tree, with lung lobes of different compliances, using various ventilation modes. The bronchial tree was obtained from Respiratory Drug Delivery (RDD Online, Richmond, VA, USA), processed and printed by a dual extruder FFF 3D printer. The test system was also composed of left side double-lumen endotracheal tube, Siemens Test Lung 190 and anesthetic breathing bag (as lobes). Pressure and flow measurements were taken at the outlets of the secondary bronchus. The measured resistance increased six times in the presence of double-lumen ETT. Differences between the flow distribution to the less and more compliant lobe were more significant for the airways with double-lumen ETT. The ability to predict the actual flow distribution in model airways is necessary to conduct effective ILV in clinical conditions. Full article
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15 pages, 2268 KiB  
Article
Calculation of Mass Transfer and Cell-Specific Consumption Rates to Improve Cell Viability in Bioink Tissue Constructs
by Axel Pössl, David Hartzke, Peggy Schlupp and Frank E. Runkel
Materials 2021, 14(16), 4387; https://doi.org/10.3390/ma14164387 - 05 Aug 2021
Cited by 1 | Viewed by 2187
Abstract
Biofabrication methods such as extrusion-based bioprinting allow the manufacture of cell-laden structures for cell therapy, but it is important to provide a sufficient number of embedded cells for the replacement of lost functional tissues. To address this issue, we investigated mass transfer rates [...] Read more.
Biofabrication methods such as extrusion-based bioprinting allow the manufacture of cell-laden structures for cell therapy, but it is important to provide a sufficient number of embedded cells for the replacement of lost functional tissues. To address this issue, we investigated mass transfer rates across a bioink hydrogel for the essential nutrients glucose and glutamine, their metabolites lactate and ammonia, the electron acceptor oxygen, and the model protein bovine serum albumin. Diffusion coefficients were calculated for these substances at two temperatures. We could confirm that diffusion depends on the molecular volume of the substances if the bioink has a high content of polymers. The analysis of pancreatic 1.1B4 β-cells revealed that the nitrogen source glutamine is a limiting nutrient for homeostasis during cultivation. Taking the consumption rates of 1.1B4 β-cells into account during cultivation, we were able to calculate the cell numbers that can be adequately supplied by the cell culture medium and nutrients in the blood using a model tissue construct. For blood-like conditions, a maximum of ~106 cells·mL−1 was suitable for the cell-laden construct, as a function of the diffused substrate and cell consumption rate for a given geometry. We found that oxygen and glutamine were the limiting nutrients in our model. Full article
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12 pages, 3072 KiB  
Article
3D Plotting of Silica/Collagen Xerogel Granules in an Alginate Matrix for Tissue-Engineered Bone Implants
by Sina Rößler, Andreas Brückner, Iris Kruppke, Hans-Peter Wiesmann, Thomas Hanke and Benjamin Kruppke
Materials 2021, 14(4), 830; https://doi.org/10.3390/ma14040830 - 09 Feb 2021
Cited by 5 | Viewed by 2408
Abstract
Today, materials designed for bone regeneration are requested to be degradable and resorbable, bioactive, porous, and osteoconductive, as well as to be an active player in the bone-remodeling process. Multiphasic silica/collagen Xerogels were shown, earlier, to meet these requirements. The aim of the [...] Read more.
Today, materials designed for bone regeneration are requested to be degradable and resorbable, bioactive, porous, and osteoconductive, as well as to be an active player in the bone-remodeling process. Multiphasic silica/collagen Xerogels were shown, earlier, to meet these requirements. The aim of the present study was to use these excellent material properties of silica/collagen Xerogels and to process them by additive manufacturing, in this case 3D plotting, to generate implants matching patient specific shapes of fractures or lesions. The concept is to have Xerogel granules as active major components embedded, to a large proportion, in a matrix that binds the granules in the scaffold. By using viscoelastic alginate as matrix, pastes of Xerogel granules were processed via 3D plotting. Moreover, alginate concentration was shown to be the key to a high content of irregularly shaped Xerogel granules embedded in a minimum of matrix phase. Both the alginate matrix and Xerogel granules were also shown to influence viscoelastic behavior of the paste, as well as the dimensionally stability of the scaffolds. In conclusion, 3D plotting of Xerogel granules was successfully established by using viscoelastic properties of alginate as matrix phase. Full article
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12 pages, 2068 KiB  
Article
3D-Printed Hermetic Alumina Housings
by Max Eickenscheidt, Michael Langenmair, Ahmad Dbouk, Dorit Nötzel, Thomas Hanemann and Thomas Stieglitz
Materials 2021, 14(1), 200; https://doi.org/10.3390/ma14010200 - 03 Jan 2021
Cited by 16 | Viewed by 3786
Abstract
Ceramics are repeatedly investigated as packaging materials because of their gas tightness, e.g., as hermetic implantable housing. Recent advances also make it possible to print the established aluminum oxide in a Fused Filament Fabrication process, creating new possibilities for manufacturing personalized devices with [...] Read more.
Ceramics are repeatedly investigated as packaging materials because of their gas tightness, e.g., as hermetic implantable housing. Recent advances also make it possible to print the established aluminum oxide in a Fused Filament Fabrication process, creating new possibilities for manufacturing personalized devices with complex shapes. This study was able to achieve integration of channels with a diameter of 500 µm (pre-sintered) with a nozzle size of 250 µm (layer thickness 100 µm) and even closed hemispheres were printed without support structures. During sintering, the weight-bearing feedstock shrinks by 16.7%, resulting in a relative material density of 96.6%. The well-known challenges of the technology such as surface roughness (Ra = 15–20 µm) and integrated cavities remain. However, it could be shown that the hollow structures in bulk do not represent a mechanical weak point and that the material can be gas-tight (<10−12 mbar s−1). For verification, a volume-free helium leak test device was developed and validated. Finally, platinum coatings with high adhesion examined the functionalization of the ceramic. All the prerequisites for hermetic housings with integrated metal structures are given, with a new level of complexity of ceramic shapes available. Full article
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2020

Jump to: 2024, 2023, 2022, 2021

13 pages, 2611 KiB  
Article
Selective Laser Melting of Patient Individualized Osteosynthesis Plates—Digital to Physical Process Chain
by André Edelmann, Monique Dubis and Ralf Hellmann
Materials 2020, 13(24), 5786; https://doi.org/10.3390/ma13245786 - 18 Dec 2020
Cited by 18 | Viewed by 2240
Abstract
We report on the exemplified realization of a digital to physical process chain for a patient individualized osteosynthesis plate for the tarsal bone area. Anonymized patient-specific data of the right feet were captured by computer tomography, which were then digitally processed to generate [...] Read more.
We report on the exemplified realization of a digital to physical process chain for a patient individualized osteosynthesis plate for the tarsal bone area. Anonymized patient-specific data of the right feet were captured by computer tomography, which were then digitally processed to generate a surface file format (standard tessellation language, STL) ready for additive manufacturing. Physical realization by selective laser melting in titanium using optimized parameter settings and post-processing by stress relief annealing results in a customized osteosynthesis plate with superior properties fulfilling medical demands. High fitting accuracy was demonstrated by applying the osteosynthesis plate to an equally good 3D printed bone model, which likewise was generated using the patient-specific computer tomography (CT) data employing selective laser sintering and polyamid 12. Proper fixation has been achieved without any further manipulation of the plate using standard screws, proving that based on CT data, individualized implants well adapted to the anatomical conditions can be accomplished without the need for additional steps, such as bending, cutting and shape trimming of precast bone plates during the surgical intervention. Beyond parameter optimization for selective laser melting, this exemplified digital to physical process chain highlights the potential of additive manufacturing for individualized osteosynthesis. Full article
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19 pages, 2154 KiB  
Article
AI-Optimized Technological Aspects of the Material Used in 3D Printing Processes for Selected Medical Applications
by Izabela Rojek, Dariusz Mikołajewski, Ewa Dostatni and Marek Macko
Materials 2020, 13(23), 5437; https://doi.org/10.3390/ma13235437 - 29 Nov 2020
Cited by 54 | Viewed by 4202
Abstract
While the intensity, complexity, and specificity of robotic exercise may be supported by patient-tailored three-dimensional (3D)-printed solutions, their performance can still be compromised by non-optimal combinations of technological parameters and material features. The main focus of this paper was the computational optimization of [...] Read more.
While the intensity, complexity, and specificity of robotic exercise may be supported by patient-tailored three-dimensional (3D)-printed solutions, their performance can still be compromised by non-optimal combinations of technological parameters and material features. The main focus of this paper was the computational optimization of the 3D-printing process in terms of features and material selection in order to achieve the maximum tensile force of a hand exoskeleton component, based on artificial neural network (ANN) optimization supported by genetic algorithms (GA). The creation and 3D-printing of the selected component was achieved using Cura 0.1.5 software and 3D-printed using fused filament fabrication (FFF) technology. To optimize the material and process parameters we compared ten selected parameters of the two distinct printing materials (polylactic acid (PLA), PLA+) using ANN supported by GA built and trained in the MATLAB environment. To determine the maximum tensile force of the exoskeleton, samples were tested using an INSTRON 5966 universal testing machine. While the balance between the technical requirements and user safety constraints requires further analysis, the PLA-based 3D-printing parameters have been optimized. Additive manufacturing may support the successful printing of usable/functional exoskeleton components. The network indicated which material should be selected: Namely PLA+. AI-based optimization may play a key role in increasing the performance and safety of the final product and supporting constraint satisfaction in patient-tailored solutions. Full article
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11 pages, 6282 KiB  
Communication
3D Printed Model of Extrahepatic Biliary Ducts for Biliary Stent Testing
by Joanna Thomas, Sagar Patel, Leia Troop, Robyn Guru, Nicholas Faist, Brian J. Bellott and Bethany A. Esterlen
Materials 2020, 13(21), 4788; https://doi.org/10.3390/ma13214788 - 27 Oct 2020
Cited by 7 | Viewed by 6050
Abstract
Several inflammatory conditions of the bile ducts cause strictures that prevent the drainage of bile into the gastrointestinal tract. Non-pharmacological treatments to re-establish bile flow include plastic or self-expanding metal stents (SEMs) that are inserted in the bile ducts during endoscopic retrograde cholangiopancreatography [...] Read more.
Several inflammatory conditions of the bile ducts cause strictures that prevent the drainage of bile into the gastrointestinal tract. Non-pharmacological treatments to re-establish bile flow include plastic or self-expanding metal stents (SEMs) that are inserted in the bile ducts during endoscopic retrograde cholangiopancreatography (ERCP) procedures. The focus of this study was to 3D print an anatomically accurate model of the extrahepatic bile ducts (EHBDs) with tissue-like mechanical properties to improve in vitro testing of stent prototypes. Following generation of an EHBD model via computer aided design (CAD), we tested the ability of Formlabs SLA 3D printers to precisely print the model with polymers selected based on the desired mechanical properties. We found the printers were reliable in printing the dimensionally accurate EHBD model with candidate polymers. Next, we evaluated the mechanical properties of Formlabs Elastic (FE), Flexible (FF), and Durable (FD) resins pre- and post-exposure to water, saline, or bile acid solution at 37 °C for up to one week. FE possessed the most bile duct-like mechanical properties based on its elastic moduli, percent elongations at break, and changes in mass under all liquid exposure conditions. EHBD models printed in FE sustained no functional damage during biliary stent deployment or when tube connectors were inserted, and provided a high level of visualization of deployed stents. These results demonstrate that our 3D printed EHBD model facilitates more realistic pre-clinical in vitro testing of biliary stent prototypes. Full article
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18 pages, 12951 KiB  
Article
Determination of the Elasticity Modulus of Additively Manufactured Wrist Hand Orthoses
by Krzysztof Łukaszewski, Radosław Wichniarek and Filip Górski
Materials 2020, 13(19), 4379; https://doi.org/10.3390/ma13194379 - 01 Oct 2020
Cited by 12 | Viewed by 2503
Abstract
The article describes the experimental and simulation research on the material properties of the individualized wrist orthoses produced in the additive manufacturing (AM) process by the fused filament fabrication (FFF) method. The authors produced a series of standard (normalized) samples for three-point bending [...] Read more.
The article describes the experimental and simulation research on the material properties of the individualized wrist orthoses produced in the additive manufacturing (AM) process by the fused filament fabrication (FFF) method. The authors produced a series of standard (normalized) samples for three-point bending from acrylonitrile butadiene styrene (ABS) filament on a low-budget 3D printer and a series of samples in the shape of a fragment of the orthosis and the entire orthosis. All types of samples were subjected to experimental tests on a universal testing machine, which allowed us to determine the modulus of elasticity of the produced materials by comparing it with finite element method (FEM) simulation models in the ABAQUS environment. The adopted research methodology allowed us to compare the material properties of the material of the entire product—wrist hand orthosis (WHO)—with the material properties of standard bending samples. The obtained values of Young’s modulus are characterized by a large discrepancy between the standard samples and the entire orthosis. On the other hand, the samples with the shape of the middle part of the orthosis were similar in the value of Young’s modulus to the results obtained during the examination of the complete orthosis. Full article
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18 pages, 7432 KiB  
Article
An Integration of a Peristaltic Pump-Based Extruder into a 3D Bioprinter Dedicated to Hydrogels
by Dorota Bociaga, Mateusz Bartniak, Krzysztof Sobczak and Karolina Rosinska
Materials 2020, 13(19), 4237; https://doi.org/10.3390/ma13194237 - 23 Sep 2020
Cited by 8 | Viewed by 3546
Abstract
The 3D printing technologies used for medical applications are mostly based on paste extruders. These are designed for high capacity, and thus often feature large material reservoirs and large diameter nozzles. A major challenge for most 3D printing platforms is a compromise between [...] Read more.
The 3D printing technologies used for medical applications are mostly based on paste extruders. These are designed for high capacity, and thus often feature large material reservoirs and large diameter nozzles. A major challenge for most 3D printing platforms is a compromise between speed, accuracy, and/or volume/mass of moving elements. To address these issues, we integrated a peristaltic pump into a bioprinter. That allowed for combining the most important requirements: high precision, a large material reservoir, and safety of biological material. The system of a fully heated nozzle and a cooled print bed were developed to maintain the optimal hydrogel temperature and crosslinking speed. Our modifications of the bioprinter design improved the mechanical properties of the printouts and their accuracy while maintaining the maximal survival rate of cells and increasing the capacity of the bioink reservoir. Full article
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19 pages, 5627 KiB  
Article
Experimental Studies on 3D Printing of Automatically Designed Customized Wrist-Hand Orthoses
by Filip Górski, Radosław Wichniarek, Wiesław Kuczko, Magdalena Żukowska, Monika Lulkiewicz and Przemysław Zawadzki
Materials 2020, 13(18), 4091; https://doi.org/10.3390/ma13184091 - 15 Sep 2020
Cited by 44 | Viewed by 5122
Abstract
The paper presents results of research conducted on a batch of additively manufactured individualized openwork wrist–hand orthoses made of thermoplastics and designed automatically based on 3D-scanned geometry of a given patient. The aim of the work was to establish an automated design process [...] Read more.
The paper presents results of research conducted on a batch of additively manufactured individualized openwork wrist–hand orthoses made of thermoplastics and designed automatically based on 3D-scanned geometry of a given patient. The aim of the work was to establish an automated design process and find a reliable set of parameters for rapid and affordable manufacturing of usable orthoses on popular 3D printers, with little or no supervision of the process. The paper presents motivations, methodology of automated design, plan of manufacturing and testing, the obtained results in terms of process stability, fit and assessment by patient and strength of the obtained orthoses. Almost 100 manufacturing processes of ready-to-use orthosis parts were carried out in a controlled environment and their results were analyzed thoroughly. The results are promising, as most of the obtained products fulfil the strength criteria, although not all of them meet the economic criteria. As a result, a recommended set of process parameters was determined. These parameters were included in a prototype of the automated design and in a production system developed by the authors. Full article
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25 pages, 3456 KiB  
Review
Utilization of Carbon Nanotubes in Manufacturing of 3D Cartilage and Bone Scaffolds
by Tomasz Szymański, Adam Aron Mieloch, Magdalena Richter, Tomasz Trzeciak, Ewa Florek, Jakub Dalibor Rybka and Michael Giersig
Materials 2020, 13(18), 4039; https://doi.org/10.3390/ma13184039 - 11 Sep 2020
Cited by 24 | Viewed by 4064
Abstract
Cartilage and bone injuries are prevalent ailments, affecting the quality of life of injured patients. Current methods of treatment are often imperfect and pose the risk of complications in the long term. Therefore, tissue engineering is a rapidly developing branch of science, which [...] Read more.
Cartilage and bone injuries are prevalent ailments, affecting the quality of life of injured patients. Current methods of treatment are often imperfect and pose the risk of complications in the long term. Therefore, tissue engineering is a rapidly developing branch of science, which aims at discovering effective ways of replacing or repairing damaged tissues with the use of scaffolds. However, both cartilage and bone owe their exceptional mechanical properties to their complex ultrastructure, which is very difficult to reproduce artificially. To address this issue, nanotechnology was employed. One of the most promising nanomaterials in this respect is carbon nanotubes, due to their exceptional physico-chemical properties, which are similar to collagens—the main component of the extracellular matrix of these tissues. This review covers the important aspects of 3D scaffold development and sums up the existing research tackling the challenges of scaffold design. Moreover, carbon nanotubes-reinforced bone and cartilage scaffolds manufactured using the 3D bioprinting technique will be discussed as a novel tool that could facilitate the achievement of more biomimetic structures. Full article
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8 pages, 4331 KiB  
Article
Investigating the Response of Human Neutrophils to Hydrophilic and Hydrophobic Micro-Rough Titanium Surfaces
by Karim El Kholy, Daniel Buser, Julia-Gabriella Wittneben, Dieter D. Bosshardt, Thomas E. Van Dyke and Michael J. Kowolik
Materials 2020, 13(15), 3421; https://doi.org/10.3390/ma13153421 - 03 Aug 2020
Cited by 9 | Viewed by 2738
Abstract
Various treatments have been used to change both the topography and chemistry of titanium surfaces, aiming to enhance tissue response and reduce healing times of endosseous implants. Most studies to date focused on bone healing around dental implants occurring later during the healing [...] Read more.
Various treatments have been used to change both the topography and chemistry of titanium surfaces, aiming to enhance tissue response and reduce healing times of endosseous implants. Most studies to date focused on bone healing around dental implants occurring later during the healing cascade. However, the impact of the initial inflammatory response in the surgical wound site on the success and healing time of dental implants is crucial for implant integration and success, yet it is still poorly understood. The purpose of this study was to investigate the effect of titanium surface hydrophilicity on the response of human neutrophils by monitoring oxygen radical production, which was measured as chemiluminescence activity. Materials and Methods: Neutrophils were isolated from human donors’ blood buffy coats using the double sucrose gradient method. Neutrophils were exposed to both hydrophilic and hydrophobic titanium surfaces with identical topographies in the presence and absence of human serum. This resulted in six experimental groups including two different implant surfaces, with and without exposure to human serum, and two control groups including an active control with cells alone and a passive control with no cells. Two samples from each group were fixed and analyzed by SEM. Comparisons between surface treatments for differences in chemiluminescence values were performed using analysis of variance ANOVA. Results and Conclusion: In the absence of exposure to serum, there was no significant difference noted between the reaction of neutrophils to hydrophilic and hydrophobic surfaces. However, there was a significant reduction in the mean and active chemiluminescence activity of neutrophils to serum-coated hydrophilic titanium surfaces than to serum-coated hydrophobic titanium surfaces. This suggests that surface hydrophilicity promotes enhanced adsorption of serum proteins, which leads to decreased provocation of initial immune cells and reduction of local oxygen radical production during wound healing. This can help explain the faster osseointegration demonstrated by hydrophilic titanium implants. Full article
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16 pages, 4720 KiB  
Article
3D-Printed Drug Delivery Systems: The Effects of Drug Incorporation Methods on Their Release and Antibacterial Efficiency
by Bahaa Shaqour, Inés Reigada, Żaneta Górecka, Emilia Choińska, Bart Verleije, Koen Beyers, Wojciech Święszkowski, Adyary Fallarero and Paul Cos
Materials 2020, 13(15), 3364; https://doi.org/10.3390/ma13153364 - 29 Jul 2020
Cited by 11 | Viewed by 3945
Abstract
Additive manufacturing technologies have been widely used in the medical field. More specifically, fused filament fabrication (FFF) 3D-printing technology has been thoroughly investigated to produce drug delivery systems. Recently, few researchers have explored the possibility of directly 3D printing such systems without the [...] Read more.
Additive manufacturing technologies have been widely used in the medical field. More specifically, fused filament fabrication (FFF) 3D-printing technology has been thoroughly investigated to produce drug delivery systems. Recently, few researchers have explored the possibility of directly 3D printing such systems without the need for producing a filament which is usually the feedstock material for the printer. This was possible via direct feeding of a mixture consisting of the carrier polymer and the required drug. However, as this direct feeding approach shows limited homogenizing abilities, it is vital to investigate the effect of the pre-mixing step on the quality of the 3D printed products. Our study investigates the two commonly used mixing approaches—solvent casting and powder mixing. For this purpose, polycaprolactone (PCL) was used as the main polymer under investigation and gentamicin sulfate (GS) was selected as a reference. The produced systems’ efficacy was investigated for bacterial and biofilm prevention. Our data show that the solvent casting approach offers improved drug distribution within the polymeric matrix, as was observed from micro-computed topography and scanning electron microscopy visualization. Moreover, this approach shows a higher drug release rate and thus improved antibacterial efficacy. However, there were no differences among the tested approaches in terms of thermal and mechanical properties. Full article
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