1
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Xiang Y, Yan J, Bao X, Gleadall A, Sun T. Investigation of cell infiltration and colonization in 3D porous scaffolds via integrated experimental and computational strategies. J Biotechnol 2024; 382:78-87. [PMID: 38307299 DOI: 10.1016/j.jbiotec.2024.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 01/29/2024] [Indexed: 02/04/2024]
Abstract
This study aimed to integrate experimental and computational methods to systematically investigate cell infiltration and colonization within porous scaffolds. Poly(lactic acid) discs (Diameter: 6 mm; Thickness: 500 µm) with open pores (Diameter: 400-1100 µm), corners (Angle: 30-120°) and gaps (Distance: 100-500 µm), and cellulosic scaffolds with irregular pores (Diameter: 50-300 µm) were situated in tissue culture plates and cultured with human dermal fibroblasts (HDFs). Both phase contrast and scanning electron microscopy revealed that HDFs initially proliferated on scaffold surfaces, then infiltrated into the porous structures via cell bridging and stacking strategies, which was affected by the initial cell seeding densities, porous structures and culture times. Based on the density-dependent cell growths in two-dimensional cell cultures, power law models were developed to quantitatively simulate cell growths on scaffold surfaces. Model analysis predicted the effect of cell seeding efficiency on cell infiltrations into the porous scaffolds, which was further validated via series cell seeding experiments. The novelty of this research lies in the incorporation of multiple experimental and computational strategies, which enables the mechanistic insights of cell invasion and colonization in porous scaffolds, also facilitates the development of suitable bioprocesses for cell seeding and tissue manufacturing in Tissue Engineering and Regenerative Medicine.
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Affiliation(s)
- Yu Xiang
- Department of Materials, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Jiongyi Yan
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Xujin Bao
- Department of Materials, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Andrew Gleadall
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Tao Sun
- Department of Chemical Engineering, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK.
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2
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Zhang B, Belton P, Teoh XY, Gleadall A, Bibb R, Qi S. An investigation into the effects of ink formulations of semi-solid extrusion 3D printing on the performance of printed solid dosage forms. J Mater Chem B 2023; 12:131-144. [PMID: 38050731 DOI: 10.1039/d3tb01868g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
Semi-solid extrusion (SSE) 3D printing has recently attracted increased attention for its pharmaceutical application as a potential method for small-batch manufacturing of personalised solid dosage forms. It has the advantage of allowing ambient temperature printing, which is especially beneficial for the 3D printing of thermosensitive drugs. In this study, the effects of polymeric compositions (single hydroxypropyl methylcellulose (HPMC) system and binary HPMC + polyvinylpyrrolidone (PVP) system), disintegrant (silicon oxide (SiO2)), and active pharmaceutical ingredients (tranexamic acid (TXA) and paracetamol (PAC)) on the printability of semisolid inks and the qualities of SSE printed drug-loaded tablets were investigated. Printability is defined by the suitability of the material for the process in terms of its physical properties during extrusions and post-extrusion, including rheology, solidification time, avoiding slumping, etc. The rheological properties of the inks were investigated as a function of polymeric compositions and drug concentrations and further correlated with the printability of the inks. The SSE 3D printed tablets were subjected to a series of physicochemical properties characterisations and in vitro drug release performance evaluations. The results indicated that an addition of SiO2 would improve 3D printing shape fidelity (e.g., pore area and porosity) by altering the ink rheology. The pores of HPMC + PVP + 5PAC prints completely disappeared after 12 hours of drying (pore area = 0 mm2). An addition of SiO2 significantly improved the pore area of the prints which are 3.5 ± 0.1 mm2. It was noted that the drug release profile of PAC significantly increased (p < 0.05) when additive SiO2 was incorporated in the formulation. This could be due to a significantly higher porosity of HPMC + PVP + SiO2 + PAC (70.3 ± 0.2%) compared to HPMC + PVP + PAC (47.6 ± 2.1%). It was also likely that SiO2 acted as a disintegrant speeding up the drug release process. Besides, the incorporation of APIs with different aqueous solubilities, as well as levels of interaction with the polymeric system showed significant impacts on the structural fidelity and subsequently the drug release performance of 3D printed tablets.
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Affiliation(s)
- Bin Zhang
- School of Pharmacy, University of East Anglia, Norwich, UK.
- Department of Mechanical and Aerospace Engineering, Brunel University London, London, UK.
| | - Peter Belton
- School of Chemistry, University of East Anglia, Norwich, UK
| | - Xin Yi Teoh
- School of Pharmacy, University of East Anglia, Norwich, UK.
- School of Pharmacy, University College London, London, UK
| | - Andrew Gleadall
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, UK
| | - Richard Bibb
- Nottingham School of Art & Design, Nottingham Trent University, UK
| | - Sheng Qi
- School of Pharmacy, University of East Anglia, Norwich, UK.
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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 Print Addit Manuf 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] [What about the content of this article? (0)] [Affiliation(s)] [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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4
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Xiang Y, Yan J, Bao X, Gleadall A, Roach P, Sun T. Evaluation of Polymeric Particles for Modular Tissue Cultures in Developmental Engineering. Int J Mol Sci 2023; 24:ijms24065234. [PMID: 36982306 PMCID: PMC10049291 DOI: 10.3390/ijms24065234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 03/30/2023] Open
Abstract
Developmental engineering (DE) aims to culture mammalian cells on corresponding modular scaffolds (scale: micron to millimeter), then assemble these into functional tissues imitating natural developmental biology processes. This research intended to investigate the influences of polymeric particles on modular tissue cultures. When poly(methyl methacrylate) (PMMA), poly(lactic acid) (PLA) and polystyrene (PS) particles (diameter: 5-100 µm) were fabricated and submerged in culture medium in tissue culture plastics (TCPs) for modular tissue cultures, the majority of adjacent PMMA, some PLA but no PS particles aggregated. Human dermal fibroblasts (HDFs) could be directly seeded onto large (diameter: 30-100 µm) PMMA particles, but not small (diameter: 5-20 µm) PMMA, nor all the PLA and PS particles. During tissue cultures, HDFs migrated from the TCPs surfaces onto all the particles, while the clustered PMMA or PLA particles were colonized by HDFs into modular tissues with varying sizes. Further comparisons revealed that HDFs utilized the same cell bridging and stacking strategies to colonize single or clustered polymeric particles, and the finely controlled open pores, corners and gaps on 3D-printed PLA discs. These observed cell-scaffold interactions, which were then used to evaluate the adaptation of microcarrier-based cell expansion technologies for modular tissue manufacturing in DE.
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Affiliation(s)
- Yu Xiang
- Department of Materials, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Jiongyi Yan
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Xujin Bao
- Department of Materials, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Andrew Gleadall
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Paul Roach
- Department of Chemistry, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
| | - Tao Sun
- Department of Chemical Engineering, Loughborough University, Epinal Way, Loughborough LE11 3TU, UK
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5
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Hewavidana Y, Balci MN, Gleadall A, Pourdeyhimi B, Silberschmidt VV, Demirci E. Assessing Crimp of Fibres in Random Networks with 3D Imaging. Polymers (Basel) 2023; 15:polym15041050. [PMID: 36850332 PMCID: PMC9966919 DOI: 10.3390/polym15041050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/05/2023] [Accepted: 02/13/2023] [Indexed: 02/22/2023] Open
Abstract
The analysis of fibrous structures using micro-computer tomography (µCT) is becoming more important as it provides an opportunity to characterise the mechanical properties and performance of materials. This study is the first attempt to provide computations of fibre crimp for various random fibrous networks (RFNs) based on µCT data. A parametric algorithm was developed to compute fibre crimp in fibres in a virtual domain. It was successfully tested for six different X-ray µCT models of nonwoven fabrics. Computations showed that nonwoven fabrics with crimped fibres exhibited higher crimp levels than those with non-crimped fibres, as expected. However, with the increased fabric density of the non-crimped nonwovens, fibres tended to be more crimped. Additionally, the projected fibre crimp was computed for all three major 2D planes, and the obtained results were statistically analysed. Initially, the algorithm was tested for a small-size, nonwoven model containing only four fibres. The fraction of nearly straight fibres was computed for both crimped and non-crimped fabrics. The mean value of the fibre crimp demonstrated that fibre segments between intersections were almost straight. However, it was observed that there were no perfectly straight fibres in the analysed RFNs. This study is applicable to approach employing a finite-element analysis (FEA) and computational fluid dynamics (CFD) to model/analyse RFNs.
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Affiliation(s)
- Yasasween Hewavidana
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
| | - Mehmet N. Balci
- Department of Mechanical Engineering, Hacettepe University, Ankara 06800, Turkey
| | - Andrew Gleadall
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
| | - Behnam Pourdeyhimi
- The Nonwovens Institute, North Carolina State University, 1010 Main Campus Dr, Raleigh, NC 27606, USA
| | - Vadim V. Silberschmidt
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
| | - Emrah Demirci
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
- Correspondence:
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6
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Zhang B, Teoh XY, Yan J, Gleadall A, Belton P, Bibb R, Qi S. Development of combi-pills using the coupling of semi-solid syringe extrusion 3D printing with fused deposition modelling. Int J Pharm 2022; 625:122140. [PMID: 36031167 DOI: 10.1016/j.ijpharm.2022.122140] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/20/2022] [Accepted: 08/21/2022] [Indexed: 01/10/2023]
Abstract
Three-dimensional (3D) printing allows for the design and printing of more complex designs than traditional manufacturing processes. For the manufacture of personalised medicines, such an advantage could enable the production of personalised drug products on demand. In this study, two types of extrusion-based 3D printing techniques, semi-solid syringe extrusion 3D printing and fused deposition modelling, were used to fabricate a combi-layer construct (combi-pill). Two model drugs, tranexamic acid (water soluble, rapid release) and indomethacin (poorly water-soluble, extended release), were printed with different geometries and materials compositions. Fourier transform infrared spectroscopy results showed that there were no interactions detected between drug-drug and drug-polymers. The printed combi-pills demonstrated excellent abrasion resisting properties in friability tests. The use of different functional excipients demonstrated significant impact on in vitro drug release of the model drugs incorporated in two 3D printed layers. Tranexamic acid and indomethacin were successfully 3D printed as a combi-pill with immediate-release and sustained-release profiles, respectively, to target quick anti-bleeding and prolonged anti-inflammation functions. For the first time, this paper systematically demonstrates the feasibility of coupling syringe-based extrusion 3D printing and fused deposition modelling as an innovative platform for various drug therapy productions, facilitating a new era of personalised combi-pills development.
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Affiliation(s)
- Bin Zhang
- School of Pharmacy, University of East Anglia, Norwich, UK
| | - Xin Yi Teoh
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | - Jiongyi Yan
- School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, UK
| | - Andrew Gleadall
- School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, UK
| | - Peter Belton
- School of Chemistry, University of East Anglia, Norwich, UK
| | - Richard Bibb
- School of Design and Creative Arts, Loughborough University, Loughborough, UK
| | - Sheng Qi
- School of Pharmacy, University of East Anglia, Norwich, UK.
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7
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Lu Y, Han XX, Gleadall A, Zhao LG. Fracture Toughness of Three-Dimensional Stereolithography Printed Polymer Reinforced with Continuous Carbon Fibers. 3D Print Addit Manuf 2022; 9:278-287. [PMID: 36660232 PMCID: PMC9831550 DOI: 10.1089/3dp.2020.0310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Additive manufacturing of fiber-reinforced polymers is one of the latest technical developments in composites manufacturing. However, there is a severe shortage of research into continuous fiber-reinforced polymers manufactured through stereolithography. For the first time, this article investigates the fracture properties of continuous carbon fiber-reinforced polymer produced by three-dimensional stereolithography printing. Compact tension (CT) specimens, both plain and fiber reinforced, were produced and tested systematically. The results showed a significant improvement in fracture toughness for fiber-reinforced specimens when compared with plain ones. The positioning of fiber bundles had a substantial effect on fracture properties, and a higher fracture toughness was reported for specimens with the fiber bundle placed closer to the crack tip. By increasing the number of fiber bundles, a significant increase in fracture toughness was reported when compared with the sample with a single fiber bundle, indicating a strong contribution of fiber volume. Also, the contribution appeared to be most effective when the fiber bundles were placed symmetrically in the thickness direction. The study is of importance and value for the development of the stereolithography technique in manufacturing continuous fiber-reinforced composites with enhanced mechanical properties.
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Affiliation(s)
- Yue Lu
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom
| | - Xiao Xiao Han
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Hunan, China
| | - Andrew Gleadall
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom
| | - Li-Guo Zhao
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom
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8
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Kayali Y, Balci MN, Gleadall A, Silberschmidt VV, Demirci E. Numerical characterisation of uniformity of fibrous networks. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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9
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Chen F, Ekinci A, Li L, Cheng M, Johnson AA, Gleadall A, Han X. How do the printing parameters of fused filament fabrication and structural voids influence the degradation of biodegradable devices? Acta Biomater 2021; 136:254-265. [PMID: 34571269 DOI: 10.1016/j.actbio.2021.09.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 12/27/2022]
Abstract
Fused Filament Fabrication (FFF), a commonly used additive manufacturing technology, is now employed widely in biomedical fields for fabricating geometrically complex biodegradable devices. Structural voids arising from the printing process exist within the objects manufactured by FFF. This paper reveals the underlying mechanism of how the printing parameters and voids affect the degradation behaviours of devices made of biodegradable polyesters. It was found that both voids and internal architecture (layer height, for instance) affect the degradation rate by interacting with the reaction-diffusion process. Large suppression of the degradation rate was found when auto-catalytic hydrolysis and diffusion are significant. Degradation rate reduced in an approximately logarithmic manner as void size increased. The extent this effect depended on the strength of auto-catalytic hydrolysis and diffusion, void size and overall device size. The internal architecture of FFF products (regulated by printing parameters) influences the degradation rate by altering the diffusion speed of acid catalysts (regulated by diffusion path length). Both void size and internal architecture should be considered in fabricating biodegradable devices using FFF. STATEMENT OF SIGNIFICANCE: A geometric model that relates printing parameters with voids of FFF is developed to characterise the structure of FFF components. Such a model, when coupled with a degradation model, offers end-to-end simulation capability (e.g. from printing parameters to degradation rate) for predicting degradation properties. The model is validated against the in vitro degradation data obtained in this study. To our knowledge, the impact of printing parameters and voids on degradation is investigated here for the first time. It is found that both the void size and the internal architecture determined by the printing parameters play an essential role in regulating degradation behaviours.
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10
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Vega G, Paz R, Gleadall A, Monzón M, Alemán-Domínguez ME. Comparison of CAD and Voxel-Based Modelling Methodologies for the Mechanical Simulation of Extrusion-Based 3D Printed Scaffolds. Materials (Basel) 2021; 14:ma14195670. [PMID: 34640068 PMCID: PMC8510365 DOI: 10.3390/ma14195670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 11/30/2022]
Abstract
Porous structures are of great importance in tissue engineering. Most scaffolds are 3D printed, but there is no single methodology to model these printed parts and to apply finite element analysis to estimate their mechanical behaviour. In this work, voxel-based and geometry-based modelling methodologies are defined and compared in terms of computational efficiency, dimensional accuracy, and mechanical behaviour prediction of printed parts. After comparing the volumes and dimensions of the models with the theoretical and experimental ones, they are more similar to the theoretical values because they do not take into account dimensional variations due to the printing temperature. This also affects the prediction of the mechanical behaviour, which is not accurate compared to reality, but it makes it possible to determine which geometry is stiffer. In terms of comparison of modelling methodologies, based on process efficiency, geometry-based modelling performs better for simple or larger parts, while voxel-based modelling is more advantageous for small and complex geometries.
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Affiliation(s)
- Gisela Vega
- Mechanical Engineering Department, Campus de Tafira Baja, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas, Spain; (M.M.); (M.E.A.-D.)
- Correspondence: (G.V.); (R.P.)
| | - Rubén Paz
- Mechanical Engineering Department, Campus de Tafira Baja, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas, Spain; (M.M.); (M.E.A.-D.)
- Correspondence: (G.V.); (R.P.)
| | - Andrew Gleadall
- Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK;
| | - Mario Monzón
- Mechanical Engineering Department, Campus de Tafira Baja, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas, Spain; (M.M.); (M.E.A.-D.)
| | - María Elena Alemán-Domínguez
- Mechanical Engineering Department, Campus de Tafira Baja, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas, Spain; (M.M.); (M.E.A.-D.)
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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12
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Moetazedian A, Gleadall A, Han X, Silberschmidt VV. Effect of environment on mechanical properties of 3D printed polylactide for biomedical applications. J Mech Behav Biomed Mater 2020; 102:103510. [DOI: 10.1016/j.jmbbm.2019.103510] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/14/2019] [Accepted: 10/23/2019] [Indexed: 01/20/2023]
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13
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Moetazedian A, Gleadall A, Mele E, Silberschmidt VV. Damage in extrusion additive manufactured parts: effect of environment and cyclic loading. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.prostr.2020.10.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Ruiz-Cantu L, Gleadall A, Faris C, Segal J, Shakesheff K, Yang J. Multi-material 3D bioprinting of porous constructs for cartilage regeneration. Mater Sci Eng C Mater Biol Appl 2019; 109:110578. [PMID: 32228894 DOI: 10.1016/j.msec.2019.110578] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 11/21/2019] [Accepted: 12/19/2019] [Indexed: 12/25/2022]
Abstract
The current gold standard for nasal reconstruction after rhinectomy or severe trauma includes transposition of autologous cartilage grafts in conjunction with coverage using an autologous skin flap. Harvesting autologous cartilage requires a major additional procedure that may create donor site morbidity. Major nasal reconstruction also requires sculpting autologous cartilages to form a cartilage framework, which is complex, highly skill-demanding and very time consuming. These limitations have prompted facial reconstructive surgeons to explore different techniques such as tissue engineered cartilage. This work explores the use of multi-material 3D bioprinting with chondrocyte-laden gelatin methacrylate (GelMA) and polycaprolactone (PCL) to fabricate constructs that can potentially be used for nasal reconstruction. In this study, we have investigated the effect of 3D manufacturing parameters including temperature, needle gauge, UV exposure time, and cell carrier formulation (GelMA) on the viability and functionality of chondrocytes in bioprinted constructs. Furthermore, we printed chondrocyte-laden GelMA and PCL into composite constructs to combine biological and mechanical properties. It was found that 20% w/v GelMA was the best concentration for the 3D bioprinting of the chondrocytes without comprising the scaffold's porous structure and cell functionality. In addition, the 3D bioprinted constructs showed neocartilage formation and similar mechanical properties to nasal alar cartilage after a 50-day culture period. Neocartilage formation was also observed in the composite constructs evidenced by the presence of glycosaminoglycans and collagen type II. This study shows the feasibility of manufacturing neocartilage using chondrocytes/GelMA/PCL 3D bioprinted porous constructs which could be applied as a method for fabricating implants for nose reconstruction.
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Affiliation(s)
- Laura Ruiz-Cantu
- Centre for Additive Manufacturing, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK; Regenerative Medicine and Cellular Therapies Division, Faculty of Science, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Andrew Gleadall
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, University of Loughborough, Loughborough LE113TU, UK
| | - Callum Faris
- Department of Otorhinolaryngology and Facial Plastic Reconstructive Surgery, Poole Hospital, Poole BH15 2JB, UK
| | - Joel Segal
- Advanced Manufacturing Technology Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Kevin Shakesheff
- Regenerative Medicine and Cellular Therapies Division, Faculty of Science, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Jing Yang
- Regenerative Medicine and Cellular Therapies Division, Faculty of Science, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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Visscher DO, Gleadall A, Buskermolen JK, Burla F, Segal J, Koenderink GH, Helder MN, van Zuijlen PPM. Design and fabrication of a hybrid alginate hydrogel/poly(ε-caprolactone) mold for auricular cartilage reconstruction. J Biomed Mater Res B Appl Biomater 2018; 107:1711-1721. [PMID: 30383916 PMCID: PMC6587956 DOI: 10.1002/jbm.b.34264] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 08/14/2018] [Accepted: 09/23/2018] [Indexed: 11/11/2022]
Abstract
The aim of this study was to design and manufacture an easily assembled cartilage implant model for auricular reconstruction. First, the printing accuracy and mechanical properties of 3D-printed poly-ε-caprolactone (PCL) scaffolds with varying porosities were determined to assess overall material properties. Next, the applicability of alginate as cell carrier for the cartilage implant model was determined. Using the optimal outcomes of both experiments (in terms of (bio)mechanical properties, cell survival, neocartilage formation, and printing accuracy), a hybrid auricular implant model was developed. PCL scaffolds with 600 μm distances between strands exhibited the best mechanical properties and most optimal printing quality for further exploration. In alginate, chondrocytes displayed high cell survival (~83% after 21 days) and produced cartilage-like matrix in vitro. Alginate beads cultured in proliferation medium exhibited slightly higher compressive moduli (6 kPa) compared to beads cultured in chondrogenic medium (3.5 kPa, p > .05). The final auricular mold could be printed with 300 μm pores and high fidelity, and the injected chondrocytes survived the culture period of 21 days. The presented hybrid auricular mold appears to be an adequate model for cartilage tissue engineering and may provide a novel approach to auricular cartilage regeneration for facial reconstruction. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1711-1721, 2019.
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Affiliation(s)
- D O Visscher
- Department of Plastic, Reconstructive and Hand Surgery, Amsterdam University Medical Center, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - A Gleadall
- Manufacturing and Process Technologies, Faculty of Engineering, University of Nottingham, Nottingham, England, UK.,Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU, UK
| | - J K Buskermolen
- Department of Dermatology, Amsterdam University Medical Center, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - F Burla
- Department of Living Matter, AMOLF, Amsterdam, The Netherlands
| | - J Segal
- Manufacturing and Process Technologies, Faculty of Engineering, University of Nottingham, Nottingham, England, UK
| | - G H Koenderink
- Department of Living Matter, AMOLF, Amsterdam, The Netherlands
| | - M N Helder
- Department of Oral and Maxillofacial Surgery/Oral Pathology, Amsterdam University Medical Center, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - P P M van Zuijlen
- Department of Plastic, Reconstructive and Hand Surgery, Amsterdam University Medical Center, Amsterdam Movement Sciences, Amsterdam, The Netherlands.,Department of Plastic, Reconstructive and Hand Surgery, Red Cross Hospital, Beverwijk, The Netherlands.,Association of Dutch Burn Centers, Beverwijk, The Netherlands
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Gretzinger S, Beckert N, Gleadall A, Lee-Thedieck C, Hubbuch J. 3D bioprinting – Flow cytometry as analytical strategy for 3D cell structures. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.bprint.2018.e00023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Gleadall A, Visscher D, Yang J, Thomas D, Segal J. Review of additive manufactured tissue engineering scaffolds: relationship between geometry and performance. Burns Trauma 2018; 6:19. [PMID: 29988731 PMCID: PMC6029169 DOI: 10.1186/s41038-018-0121-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/30/2018] [Indexed: 02/07/2023]
Abstract
Material extrusion additive manufacturing has rapidly grown in use for tissue engineering research since its adoption in the year 2000. It has enabled researchers to produce scaffolds with intricate porous geometries that were not feasible with traditional manufacturing processes. Researchers can control the structural geometry through a wide range of customisable printing parameters and design choices including material, print path, temperature, and many other process parameters. Currently, the impact of these choices is not fully understood. This review focuses on how the position and orientation of extruded filaments, which sometimes referred to as the print path, lay-down pattern, or simply “scaffold design”, affect scaffold properties and biological performance. By analysing trends across multiple studies, new understanding was developed on how filament position affects mechanical properties. Biological performance was also found to be affected by filament position, but a lack of consensus between studies indicates a need for further research and understanding. In most research studies, scaffold design was dictated by capabilities of additive manufacturing software rather than free-form design of structural geometry optimised for biological requirements. There is scope for much greater application of engineering innovation to additive manufacture novel geometries. To achieve this, better understanding of biological requirements is needed to enable the effective specification of ideal scaffold geometries.
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Affiliation(s)
- Andrew Gleadall
- 1Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire LE11 3TU UK
| | - Dafydd Visscher
- Department of Plastic, Reconstructive and Hand Surgery, VU University Medical Center, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Jing Yang
- 3Faculty of Science, School of Pharmacy, University of Nottingham, University Park, Nottingham, NG7 2RD UK
| | - Daniel Thomas
- 3Dynamic Systems, Heol Ty Gwyn Industrial Estate, Bridgend, CF34 0BQ UK
| | - Joel Segal
- 5Advanced Manufacturing Technology Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD UK
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Ruiz-Cantu L, Gleadall A, Faris C, Segal J, Shakesheff K, Yang J. Characterisation of the surface structure of 3D printed scaffolds for cell infiltration and surgical suturing. Biofabrication 2016; 8:015016. [DOI: 10.1088/1758-5090/8/1/015016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Gleadall A, Pan J, Ding L, Kruft MA, Curcó D. An atomic finite element model for biodegradable polymers. Part 1. Formulation of the finite elements. J Mech Behav Biomed Mater 2015; 51:409-20. [DOI: 10.1016/j.jmbbm.2015.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/15/2015] [Indexed: 10/23/2022]
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Gleadall A, Pan J, Kruft MA, Kellomäki M. Degradation mechanisms of bioresorbable polyesters. Part 2. Effects of initial molecular weight and residual monomer. Acta Biomater 2014; 10:2233-40. [PMID: 24473239 DOI: 10.1016/j.actbio.2014.01.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 01/08/2014] [Accepted: 01/15/2014] [Indexed: 11/20/2022]
Abstract
This paper presents an understanding of how initial molecular weight and initial monomer fraction affect the degradation of bioresorbable polymers in terms of the underlying hydrolysis mechanisms. A mathematical model was used to analyse the effects of initial molecular weight for various hydrolysis mechanisms including noncatalytic random scission, autocatalytic random scission, noncatalytic end scission or autocatalytic end scission. Different behaviours were identified to relate initial molecular weight to the molecular weight half-life and to the time until the onset of mass loss. The behaviours were validated by fitting the model to experimental data for molecular weight reduction and mass loss of samples with different initial molecular weights. Several publications that consider initial molecular weight were reviewed. The effect of residual monomer on degradation was also analysed, and shown to accelerate the reduction of molecular weight and mass loss. An inverse square root law relationship was found between molecular weight half-life and initial monomer fraction for autocatalytic hydrolysis. The relationship was tested by fitting the model to experimental data with various residual monomer contents.
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Affiliation(s)
- Andrew Gleadall
- Department of Engineering, University of Leicester, Leicester LE1 7RH, UK
| | - Jingzhe Pan
- Department of Engineering, University of Leicester, Leicester LE1 7RH, UK.
| | - Marc-Anton Kruft
- Purac Biomaterials, PO Box 21, 4200 AA Gorinchem, The Netherlands
| | - Minna Kellomäki
- BioMediTech and Department of Electronics and Communications Engineering, PO Box 692, 33101 Tampere, Finland
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