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Thompson C, González C, LLorca J. Additively-manufactured Mg wire-reinforced PLDL-matrix composites for biomedical applications. J Mech Behav Biomed Mater 2024; 153:106496. [PMID: 38460456 DOI: 10.1016/j.jmbbm.2024.106496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 03/11/2024]
Abstract
Coupons of a medical grade PLDL polymer matrix uniaxially reinforced with a 15% volume fraction of Mg wires have been manufactured by fused filament fabrication for the first time. Two different types of Mg wires, without and with a surface treatment by plasma electrolytic oxidation were used. Both composite materials were subjected to degradation in phosphate buffer solution over a 3-week period, and their degradation and deformation micromechanisms were analysed in detail. Additionally, the materials were subjected to extensive mechanical testing under various loading conditions, and the interface strength was also analysed. It was found that the presence of the Mg wires improves the mechanical behaviour and accelerates the corrosion rate of the composite with respect that of the polymer matrix and these properties can be further tailored through the surface-modification of Mg wires by plasma electrolytic oxidation. The additive manufacturing strategy presented opens the path to fabricate multimaterial implants and scaffolds with complex shape and tailored properties provided by biodegradable polymers reinforced with either Mg and Zn particles and/or wires.
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Affiliation(s)
- C Thompson
- IMDEA Materials Institute, C/ Eric Kandel 2, 28906, Getafe, Madrid, Spain; Department of Material Science and Engineering, Universidad Carlos III de Madrid, 28911, Leganés, Madrid, Spain
| | - C González
- IMDEA Materials Institute, C/ Eric Kandel 2, 28906, Getafe, Madrid, Spain; Department of Material Science, Polytechnic University of Madrid, E. T. S. de Ingenieros de Caminos, 28040 Madrid, Spain
| | - J LLorca
- IMDEA Materials Institute, C/ Eric Kandel 2, 28906, Getafe, Madrid, Spain; Department of Material Science, Polytechnic University of Madrid, E. T. S. de Ingenieros de Caminos, 28040 Madrid, Spain.
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2
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Moetazedian A, Candeo A, Liu S, Hughes A, Nasrollahi V, Saadat M, Bassi A, Grover LM, Cox LR, Poologasundarampillai G. Versatile Microfluidics for Biofabrication Platforms Enabled by an Agile and Inexpensive Fabrication Pipeline. Adv Healthc Mater 2023; 12:e2300636. [PMID: 37186512 DOI: 10.1002/adhm.202300636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Indexed: 05/17/2023]
Abstract
Microfluidics have transformed diagnosis and screening in regenerative medicine. Recently, they are showing much promise in biofabrication. However, their adoption is inhibited by costly and drawn-out lithographic processes thus limiting progress. Here, multi-material fibers with complex core-shell geometries with sizes matching those of human arteries and arterioles are fabricated employing versatile microfluidic devices produced using an agile and inexpensive manufacturing pipeline. The pipeline consists of material extrusion additive manufacturing with an innovative continuously varied extrusion (CONVEX) approach to produce microfluidics with complex seamless geometries including, novel variable-width zigzag (V-zigzag) mixers with channel widths ranging from 100-400 µm and hydrodynamic flow-focusing components. The microfluidic systems facilitated rapid mixing of fluids by decelerating the fluids at specific zones to allow for increased diffusion across the interfaces. Better mixing even at high flow rates (100-1000 µL min-1 ) whilst avoiding turbulence led to high cell cytocompatibility (>86%) even when 100 µm nozzles are used. The presented 3D-printed microfluidic system is versatile, simple and efficient, offering a great potential to significantly advance the microfluidic platform in regenerative medicine.
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Affiliation(s)
- Amirpasha Moetazedian
- School of Dentistry, Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B5 7EG, UK
- EPSRC Future Metrology Hub, School of Computing and Engineering, University of Huddersfield, Huddersfield, HD1 3D, UK
| | - Alessia Candeo
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Siyun Liu
- School of Dentistry, Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B5 7EG, UK
| | - Arran Hughes
- Department of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Vahid Nasrollahi
- Department of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Mozafar Saadat
- Department of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Andrea Bassi
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133, Italy
| | - Liam M Grover
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Liam R Cox
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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Hozdić E, Hozdić E. Comparative Analysis of the Influence of Mineral Engine Oil on the Mechanical Parameters of FDM 3D-Printed PLA, PLA+CF, PETG, and PETG+CF Materials. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6342. [PMID: 37763618 PMCID: PMC10534872 DOI: 10.3390/ma16186342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 09/15/2023] [Accepted: 09/20/2023] [Indexed: 09/29/2023]
Abstract
Polymer materials and composites play a pivotal role in modern industry, prized for their durability, light weight, and resistance to corrosion. This study delves into the effects of mineral engine oil exposure on the mechanical parameters of 3D-printed materials created through fused deposition modeling (FDM). The research scrutinizes prototype materials under diverse environmental conditions, with a particular focus on the tensile parameters. The primary aim is to analyze and compare how mineral engine oil affects the mechanical parameters of four commonly used FDM 3D-printed materials: PLA, PLA+CF composites, PETG, and PETG+CF composites. In the case of the PLA specimens, the tensile strength decreased by approximately 36%, which, considering the 30% infill, remained acceptable. Simultaneously, the nominal strain at the point of breaking increased by 60.92% after 7 days and 47.49% after 30 days, indicating enhanced ductility. Interestingly, the PLA's Young's modulus remained unaffected by the oil. The 3D-printed PLA+CF materials exposed to 30 days of mineral engine oil displayed a substantial Young's modulus increase of over 49.93%. The PETG specimens exhibited intriguing behavior, with a tensile strength decrease of 16.66% after 7 days and 16.85% after 30 days, together with a notable increase in the nominal strain at breaking by 21.34% for 7 days and 14.51% for 30 days, signifying enhanced ductility. In PETG material specimens, the Young's modulus increased by 55.08% after 7 days and 66.27% after 30 days. The PETG+CF samples initially exhibited increases in tensile strength (1.78%) and nominal strain at breaking (6.08%) after 7 days, but later experienced an 11.75% reduction in the tensile strength after 30 days. This research underscores the critical role of material selection in oil-exposed environments and suggests avenues for future exploration, encompassing microstructural analysis, the long-term impact of oil exposure, and broader considerations related to environmental and oil-specific factors. It contributes to a deeper understanding of the intricate interactions between polymer materials and mineral engine oil, offering valuable insights that can enhance industrial applications.
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Affiliation(s)
- Elvis Hozdić
- Faculty of Mechanical Engineering, University of Novo Mesto, Na Loko 2, 8000 Novo Mesto, Slovenia
| | - Emine Hozdić
- Kranj School Centre, Kidričeva Cesta 55, 4000 Kranj, Slovenia;
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4
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Noroozi R, Arif ZU, Taghvaei H, Khalid MY, Sahbafar H, Hadi A, Sadeghianmaryan A, Chen X. 3D and 4D Bioprinting Technologies: A Game Changer for the Biomedical Sector? Ann Biomed Eng 2023:10.1007/s10439-023-03243-9. [PMID: 37261588 DOI: 10.1007/s10439-023-03243-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/14/2023] [Indexed: 06/02/2023]
Abstract
Bioprinting is an innovative and emerging technology of additive manufacturing (AM) and has revolutionized the biomedical sector by printing three-dimensional (3D) cell-laden constructs in a precise and controlled manner for numerous clinical applications. This approach uses biomaterials and varying types of cells to print constructs for tissue regeneration, e.g., cardiac, bone, corneal, cartilage, neural, and skin. Furthermore, bioprinting technology helps to develop drug delivery and wound healing systems, bio-actuators, bio-robotics, and bio-sensors. More recently, the development of four-dimensional (4D) bioprinting technology and stimuli-responsive materials has transformed the biomedical sector with numerous innovations and revolutions. This issue also leads to the exponential growth of the bioprinting market, with a value over billions of dollars. The present study reviews the concepts and developments of 3D and 4D bioprinting technologies, surveys the applications of these technologies in the biomedical sector, and discusses their potential research topics for future works. It is also urged that collaborative and valiant efforts from clinicians, engineers, scientists, and regulatory bodies are needed for translating this technology into the biomedical, pharmaceutical, and healthcare systems.
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Affiliation(s)
- Reza Noroozi
- School of Mechanical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran
| | - Zia Ullah Arif
- Department of Mechanical Engineering, University of Management & Technology, Lahore, Sialkot Campus, Lahore, 51041, Pakistan
| | - Hadi Taghvaei
- School of Mechanical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran
| | - Muhammad Yasir Khalid
- Department of Aerospace Engineering, Khalifa University of Science and Technology, PO Box: 127788, Abu Dhabi, United Arab Emirates
| | - Hossein Sahbafar
- School of Mechanical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran
| | - Amin Hadi
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Ali Sadeghianmaryan
- Postdoctoral Researcher Fellow at Department of Biomedical Engineering, University of Memphis, Memphis, TN, USA.
- Department of Mechanical Engineering, College of Engineering, University of Saskatchewan, 57 Campus Dr., Saskatoon, SK, S7N5A9, Canada.
| | - Xiongbiao Chen
- Department of Mechanical Engineering, College of Engineering, University of Saskatchewan, 57 Campus Dr., Saskatoon, SK, S7N5A9, Canada
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Moetazedian A, Allum J, Gleadall A, Silberschmidt VV. Bulk-Material Bond Strength Exists in Extrusion Additive Manufacturing for a Wide Range of Temperatures, Speeds, and Layer Times. 3D PRINTING AND ADDITIVE MANUFACTURING 2023; 10:514-523. [PMID: 37346192 PMCID: PMC10280202 DOI: 10.1089/3dp.2021.0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/23/2023]
Abstract
Do extrusion temperature, printing speed, and layer time affect mechanical performance of interlayer bonds in material extrusion additive manufacturing (MEAM)? The question is one of the main challenges in 3D printing of polymers. This article aims to analyze the independent effect of printing parameters on interlayer bonding in MEAM. In previous research, printing parameters were unavoidably interrelated, such as printing speed and layer cooling time. Here, original specimen designs allow the effects to be studied independently for the first time to provide new understanding of the effects of a wide range of thermal factors on mechanical properties of 3D-printed polylactide. The experimental approach used direct GCode design to manufacture specially designed single-filament-thick specimens for tensile testing to measure mechanical and thermal properties normal to the interface between layers. In total, five different extrusion temperatures (a range of 60°C), five different printing speeds (a 16-fold change in the magnitude) and four different layer times (an 8-fold change) were independently studied. The results demonstrate interlayer bond strength to be equivalent to that of the bulk material within experimental scatter. This study provides strong evidence about the crucial role of microscale geometry for apparent interlayer bond strength relative to the role of thermal factors. By designing specimens specifically for the MEAM process, this study clearly demonstrates that bulk-material strength can be achieved for interlayer bonds in MEAM even when printing parameters change severalfold. Widespread industrial and academic efforts to improve interlayer bonding should be refocused to study extrusion geometry-the primary cause of anisotropy in MEAM.
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Affiliation(s)
- Amirpasha Moetazedian
- Wolfson School of Mechanical, Electrical, and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom
| | - James Allum
- Wolfson School of Mechanical, Electrical, and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom
| | - Andrew Gleadall
- Wolfson School of Mechanical, Electrical, and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom
| | - Vadim V. Silberschmidt
- Wolfson School of Mechanical, Electrical, and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom
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6
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Arif ZU, Khalid MY, Zolfagharian A, Bodaghi M. 4D bioprinting of smart polymers for biomedical applications: recent progress, challenges, and future perspectives. REACT FUNCT POLYM 2022. [DOI: 10.1016/j.reactfunctpolym.2022.105374] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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7
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Głowacki M, Mazurkiewicz A, Słomion M, Skórczewska K. Resistance of 3D-Printed Components, Test Specimens and Products to Work under Environmental Conditions-Review. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15176162. [PMID: 36079539 PMCID: PMC9458170 DOI: 10.3390/ma15176162] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 05/27/2023]
Abstract
The development of additive manufacturing methods known as "3D printing" started in the 1980s. In these methods, spatial models are created from a semi-finished product such as a powder, filament or liquid. The model is most often created in layers, which are created from the semi-finished product, which is most often subjected to thermal treatment or using light or ultraviolet rays. The technology of additive manufacturing has both advantages and disadvantages when compared to the traditionally used methods of processing thermoplastic materials, such as, for example, injection or extrusion. The most important advantages are low cost, flexibility and speed of manufacturing of elements with different spatial shapes. From the point of view of the user of the product, the most important disadvantages are the lower mechanical properties and lower resistance to environmental factors that occur during the use of the manufactured products. The purpose of this review is to present current information and a compilation of features in the field of research on the effects of the interactions of different types of environments on the mechanical properties of 3D-manufactured thermoplastic products. Changes in the structure and mechanical properties of the material under the influence of factors such as humidity, salt, temperature, UV rays, gasoline and the environment of the human body are presented. The presented article enables the effects of environmental conditions on common materials used in 3D printing technology to be collated in one place.
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Affiliation(s)
- Marcin Głowacki
- Department of Mechanical Engineering, Bydgoszcz University of Sciences and Technology, Kaliskiego 7 Street, 85-789 Bydgoszcz, Poland
| | - Adam Mazurkiewicz
- Department of Mechanical Engineering, Bydgoszcz University of Sciences and Technology, Kaliskiego 7 Street, 85-789 Bydgoszcz, Poland
| | - Małgorzata Słomion
- Department of Management, Bydgoszcz University of Sciences and Technology, Kaliskiego 7 Street, 85-789 Bydgoszcz, Poland
| | - Katarzyna Skórczewska
- Faculty of Technology and Chemical Engineering, University of Sciences and Technology, Seminaryjna 3, Street, 85-326 Bydgoszcz, Poland
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8
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Recent advances in 3D-printed polylactide and polycaprolactone-based biomaterials for tissue engineering applications. Int J Biol Macromol 2022; 218:930-968. [PMID: 35896130 DOI: 10.1016/j.ijbiomac.2022.07.140] [Citation(s) in RCA: 95] [Impact Index Per Article: 47.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 07/13/2022] [Accepted: 07/18/2022] [Indexed: 01/10/2023]
Abstract
The three-dimensional printing (3DP) also known as the additive manufacturing (AM), a novel and futuristic technology that facilitates the printing of multiscale, biomimetic, intricate cytoarchitecture, function-structure hierarchy, multi-cellular tissues in the complicated micro-environment, patient-specific scaffolds, and medical devices. There is an increasing demand for developing 3D-printed products that can be utilized for organ transplantations due to the organ shortage. Nowadays, the 3DP has gained considerable interest in the tissue engineering (TE) field. Polylactide (PLA) and polycaprolactone (PCL) are exemplary biomaterials with excellent physicochemical properties and biocompatibility, which have drawn notable attraction in tissue regeneration. Herein, the recent advancements in the PLA and PCL biodegradable polymer-based composites as well as their reinforcement with hydrogels and bio-ceramics scaffolds manufactured through 3DP are systematically summarized and the applications of bone, cardiac, neural, vascularized and skin tissue regeneration are thoroughly elucidated. The interaction between implanted biodegradable polymers, in-vivo and in-vitro testing models for possible evaluation of degradation and biological properties are also illustrated. The final section of this review incorporates the current challenges and future opportunities in the 3DP of PCL- and PLA-based composites that will prove helpful for biomedical engineers to fulfill the demands of the clinical field.
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9
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A Review of Polylactic Acid as a Replacement Material for Single-Use Laboratory Components. MATERIALS 2022; 15:ma15092989. [PMID: 35591324 PMCID: PMC9100125 DOI: 10.3390/ma15092989] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/04/2022] [Accepted: 04/18/2022] [Indexed: 02/04/2023]
Abstract
Every year, the EU emits 13.4 Mt of CO2 solely from plastic production, with 99% of all plastics being produced from fossil fuel sources, while those that are produced from renewable sources use food products as feedstocks. In 2019, 29 Mt of plastic waste was collected in Europe. It is estimated that 32% was recycled, 43% was incinerated and 25% was sent to landfill. It has been estimated that life-sciences (biology, medicine, etc.) alone create plastic waste of approximately 5.5 Mt/yr, the majority being disposed of by incineration. The vast majority of this plastic waste is made from fossil fuel sources, though there is a growing interest in the possible use of bioplastics as a viable alternative for single-use lab consumables, such as petri dishes, pipette tips, etc. However, to-date only limited bioplastic replacement examples exist. In this review, common polymers used for labware are discussed, along with examining the possibility of replacing these materials with bioplastics, specifically polylactic acid (PLA). The material properties of PLA are described, along with possible functional improvements dure to additives. Finally, the standards and benchmarks needed for assessing bioplastics produced for labware components are reviewed.
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10
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Popescu D, Baciu F, Amza CG, Cotrut CM, Marinescu R. The Effect of Disinfectants Absorption and Medical Decontamination on the Mechanical Performance of 3D-Printed ABS Parts. Polymers (Basel) 2021; 13:4249. [PMID: 34883752 PMCID: PMC8659898 DOI: 10.3390/polym13234249] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/23/2021] [Accepted: 12/02/2021] [Indexed: 12/13/2022] Open
Abstract
Producing parts by 3D printing based on the material extrusion process determines the formation of air gaps within layers even at full infill density, while external pores can appear between adjacent layers making prints permeable. For the 3D-printed medical devices, this open porosity leads to the infiltration of disinfectant solutions and body fluids, which might pose safety issues. In this context, this research purpose is threefold. It investigates which 3D printing parameter settings are able to block or reduce permeation, and it experimentally analyzes if the disinfectants and the medical decontamination procedure degrade the mechanical properties of 3D-printed parts. Then, it studies acetone surface treatment as a solution to avoid disinfectants infiltration. The absorption tests results indicate the necessity of applying post-processing operations for the reusable 3D-printed medical devices as no manufacturing settings can ensure enough protection against fluid intake. However, some parameter settings were proven to enhance the sealing, in this sense the layer thickness being the most important factor. The experimental outcomes also show a decrease in the mechanical performance of 3D-printed ABS (acrylonitrile butadiene styrene) instruments treated by acetone cold vapors and then medical decontaminated (disinfected, cleaned, and sterilized by hydrogen peroxide gas plasma sterilization) in comparison to the control prints. These results should be acknowledged when designing and 3D printing medical instruments.
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Affiliation(s)
- Diana Popescu
- Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania; (D.P.); (C.G.A.)
| | - Florin Baciu
- Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania; (D.P.); (C.G.A.)
| | - Catalin Gheorghe Amza
- Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, Romania; (D.P.); (C.G.A.)
| | - Cosmin Mihai Cotrut
- Faculty of Materials Science and Engineering, University Politehnica of Bucharest, 060042 Bucharest, Romania;
| | - Rodica Marinescu
- Department of Orthopedics, University of Medicine and Pharmacology Carol Davila, 020021 Bucharest, Romania;
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11
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Vallejos Baier R, Contreras Raggio JI, Toro Arancibia C, Bustamante M, Pérez L, Burda I, Aiyangar A, Vivanco JF. Structure-function assessment of 3D-printed porous scaffolds by a low-cost/open source fused filament fabrication printer. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 123:111945. [PMID: 33812577 DOI: 10.1016/j.msec.2021.111945] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/28/2021] [Accepted: 01/31/2021] [Indexed: 10/22/2022]
Abstract
Additive manufacturing encompasses a plethora of techniques to manufacture structures from a computational model. Among them, fused filament fabrication (FFF) relies on heating thermoplastics to their fusion point and extruding the material through a nozzle in a controlled pattern. FFF is a suitable technique for tissue engineering, given that allows the fabrication of 3D-scaffolds, which are utilized for tissue regeneration purposes. The objective of this study is to assess a low-cost/open-source 3D printer (In-House), by manufacturing both solid and porous samples with relevant microarchitecture in the physiological range (100-500 μm pore size), using an equivalent commercial counterpart for comparison. For this, compressive tests in solid and porous scaffolds manufactured in both printers were performed, comparing the results with finite element analysis (FEA) models. Additionally, a microarchitectural analysis was done in samples from both printers, comparing the measurements of both pore size and porosity to their corresponding computer-aided design (CAD) models. Moreover, a preliminary biological assessment was performed using scaffolds from our In-House printer, measuring cell adhesion efficiency. Finally, Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) was performed to evaluate chemical changes in the material (polylactic acid) after fabrication in each printer. The results show that the In-House printer achieved generally better mechanical behavior and resolution capacity than its commercial counterpart, by comparing with their FEA and CAD models, respectively. Moreover, a preliminary biological assessment indicates the feasibility of the In-House printer to be used in tissue engineering applications. The results also show the influence of pore geometry on mechanical properties of 3D-scaffolds and demonstrate that properties such as the apparent elastic modulus (Eapp) can be controlled in 3D-printed scaffolds.
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Affiliation(s)
- Raúl Vallejos Baier
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar, Chile.
| | | | | | - Miguel Bustamante
- Facultad de Ciencias Exactas, Universidad Andrés Bello, Santiago, Chile.
| | - Luis Pérez
- Departamento de Ingeniería Mecánica, Universidad Técnica Federico Santa María, Valparaíso, Chile.
| | - Iurii Burda
- Mechanical Systems Engineering, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
| | - Ameet Aiyangar
- Mechanical Systems Engineering, Empa - Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland; Department of Orthopaedic Surgery, University of Pittsburgh, USA.
| | - Juan F Vivanco
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar, Chile.
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12
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Moetazedian A, Gleadall A, Mele E, Silberschmidt VV. Damage in extrusion additive manufactured biomedical polymer: Effects of testing direction and environment during cyclic loading. J Mech Behav Biomed Mater 2021; 118:104397. [PMID: 33743441 DOI: 10.1016/j.jmbbm.2021.104397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 02/02/2021] [Accepted: 02/11/2021] [Indexed: 10/22/2022]
Abstract
Although biodegradable polymers were widely researched, this is the first study considering the effect of combined testing environments and cyclic loading on the most important aspect related to additive manufacturing: the interfacial bond between deposited layers. Its results give confidence in applicability of the material extrusion additive manufacturing technology for biomedical fields, by demonstrating that the interface behaves in a manner similar to that of the bulk-polymer material. To do this, especially designed tensile specimens were used to analyse the degradation of 3D-printed polymers subjected to constant-amplitude and incremental cyclic loads when tested in air at room temperature (control) and submerged at 37 °C (close to in-vivo conditions). The mechanical properties of the interface between extruded filaments were compared against the bulk material, i.e. along filaments. In both cases, cyclic loading caused only a negligible detrimental effect compared to non-cyclic loading (less than 10 % difference in ultimate tensile strength), demonstrating the suitability of using 3D-printed components in biomedical applications, usually exposed to cyclic loading. For cyclic tests with a constant loading amplitude, larger residual deformation (>100 % greater) and energy dissipation (>15 % greater) were found when testing submerged in solution at 37 °C as opposed to in laboratory conditions (air at room temperature), as used by many studies. This difference may be due to plasticisation effects of water and temperature. For cyclic tests with incrementally increasing loading amplitudes, the vast majority of energy dissipation happened in the last two cycles prior to failure, when the polymer approached the yield point. The results demonstrate the importance of using an appropriate methodology for biomedical applications; otherwise, mechanical properties may be overestimated.
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Affiliation(s)
- Amirpasha Moetazedian
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU, UK
| | - Andrew Gleadall
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU, UK.
| | - Elisa Mele
- Department of Materials, Loughborough University, Loughborough, LE11 3TU, UK
| | - Vadim V Silberschmidt
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU, UK
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