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Blanquer SBG, Grijpma DW. Triply Periodic Minimal Surfaces (TPMS) for the Generation of Porous Architectures Using Stereolithography. Methods Mol Biol 2021; 2147:19-30. [PMID: 32840807 DOI: 10.1007/978-1-0716-0611-7_2] [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] [Indexed: 06/11/2023]
Abstract
A new generation of sophisticated tissue engineering scaffolds are developed using the periodicity of trigonometric equations to generate triply periodic minimal surfaces (TPMS). TPMS architectures display minimal surface energy that induce typical pore features and surface curvatures. Here we described a series of TPMS geometries and developed a procedure to build such scaffolds by stereolithography using biocompatible and biodegradable photosensitive resins.
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Affiliation(s)
| | - Dirk W Grijpma
- MIRA Institute for Biomedical Technology and Technical Medicine, Department of Biomaterials Science and Technology, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
- Department of Biomedical Engineering, University Medical Centre Groningen, Groningen, The Netherlands
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Geven MA, Grijpma DW. Additive manufacturing of composite structures for the restoration of bone tissue. ACTA ACUST UNITED AC 2019. [DOI: 10.1088/2399-7532/ab201f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Markl D, Zeitler A, Rades T, Rantanen J, Bøtker J. Toward quality assessment of 3D printed oral dosage forms. ACTA ACUST UNITED AC 2018. [DOI: 10.2217/3dp-2017-0016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The additive manufacturing industry achieved a corporate annual growth rate of 25.9% according to the Forbes analysis of the Wohlers Report 2016. This high growth rate is placed in perspective when looking at the past 27 years where the corporate annual growth rate has averaged 26.2% each year indicating that additive manufacturing is clearly a growing industry. Such growth needs to be supported by suitable quality testing methods: with the economic success achieved in this market and the associated transition from mass production toward mass customization comes the need for new and innovative methods to assess the quality of the 3D printed geometries. This will be especially important for pharmaceutical products where a sub-standard quality of the final product can have detrimental consequences for patient health and safety. [Formula: see text]
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Affiliation(s)
- Daniel Markl
- Department of Chemical Engineering & Biotechnology, University of Cambridge, Cavendish Laboratory, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Axel Zeitler
- Department of Chemical Engineering & Biotechnology, University of Cambridge, Cavendish Laboratory, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Thomas Rades
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
- Faculty of Science & Engineering, Åbo Akademi University, Tykistökatu 6A, 20521 Turku, Finland
| | - Jukka Rantanen
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Johan Bøtker
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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Markl D, Zeitler JA, Rasch C, Michaelsen MH, Müllertz A, Rantanen J, Rades T, Bøtker J. Analysis of 3D Prints by X-ray Computed Microtomography and Terahertz Pulsed Imaging. Pharm Res 2017; 34:1037-1052. [PMID: 28004318 PMCID: PMC5382186 DOI: 10.1007/s11095-016-2083-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 12/07/2016] [Indexed: 11/04/2022]
Abstract
PURPOSE A 3D printer was used to realise compartmental dosage forms containing multiple active pharmaceutical ingredient (API) formulations. This work demonstrates the microstructural characterisation of 3D printed solid dosage forms using X-ray computed microtomography (XμCT) and terahertz pulsed imaging (TPI). METHODS Printing was performed with either polyvinyl alcohol (PVA) or polylactic acid (PLA). The structures were examined by XμCT and TPI. Liquid self-nanoemulsifying drug delivery system (SNEDDS) formulations containing saquinavir and halofantrine were incorporated into the 3D printed compartmentalised structures and in vitro drug release determined. RESULTS A clear difference in terms of pore structure between PVA and PLA prints was observed by extracting the porosity (5.5% for PVA and 0.2% for PLA prints), pore length and pore volume from the XμCT data. The print resolution and accuracy was characterised by XμCT and TPI on the basis of the computer-aided design (CAD) models of the dosage form (compartmentalised PVA structures were 7.5 ± 0.75% larger than designed; n = 3). CONCLUSIONS The 3D printer can reproduce specific structures very accurately, whereas the 3D prints can deviate from the designed model. The microstructural information extracted by XμCT and TPI will assist to gain a better understanding about the performance of 3D printed dosage forms.
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Affiliation(s)
- Daniel Markl
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - J Axel Zeitler
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Cecilie Rasch
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark
| | - Maria Høtoft Michaelsen
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark
| | - Anette Müllertz
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark
| | - Jukka Rantanen
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark
| | - Thomas Rades
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark
| | - Johan Bøtker
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen, Denmark.
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Hendrikson WJ, Deegan AJ, Yang Y, van Blitterswijk CA, Verdonschot N, Moroni L, Rouwkema J. Influence of Additive Manufactured Scaffold Architecture on the Distribution of Surface Strains and Fluid Flow Shear Stresses and Expected Osteochondral Cell Differentiation. Front Bioeng Biotechnol 2017; 5:6. [PMID: 28239606 PMCID: PMC5300985 DOI: 10.3389/fbioe.2017.00006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/23/2017] [Indexed: 01/22/2023] Open
Abstract
Scaffolds for regenerative medicine applications should instruct cells with the appropriate signals, including biophysical stimuli such as stress and strain, to form the desired tissue. Apart from that, scaffolds, especially for load-bearing applications, should be capable of providing mechanical stability. Since both scaffold strength and stress–strain distributions throughout the scaffold depend on the scaffold’s internal architecture, it is important to understand how changes in architecture influence these parameters. In this study, four scaffold designs with different architectures were produced using additive manufacturing. The designs varied in fiber orientation, while fiber diameter, spacing, and layer height remained constant. Based on micro-CT (μCT) scans, finite element models (FEMs) were derived for finite element analysis (FEA) and computational fluid dynamics (CFD). FEA of scaffold compression was validated using μCT scan data of compressed scaffolds. Results of the FEA and CFD showed a significant impact of scaffold architecture on fluid shear stress and mechanical strain distribution. The average fluid shear stress ranged from 3.6 mPa for a 0/90 architecture to 6.8 mPa for a 0/90 offset architecture, and the surface shear strain from 0.0096 for a 0/90 offset architecture to 0.0214 for a 0/90 architecture. This subsequently resulted in variations of the predicted cell differentiation stimulus values on the scaffold surface. Fluid shear stress was mainly influenced by pore shape and size, while mechanical strain distribution depended mainly on the presence or absence of supportive columns in the scaffold architecture. Together, these results corroborate that scaffold architecture can be exploited to design scaffolds with regions that guide specific tissue development under compression and perfusion. In conjunction with optimization of stimulation regimes during bioreactor cultures, scaffold architecture optimization can be used to improve scaffold design for tissue engineering purposes.
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Affiliation(s)
- Wim J Hendrikson
- Department of Tissue Regeneration, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente , Enschede , Netherlands
| | - Anthony J Deegan
- Institute for Science and Technology in Medicine, School of Medicine, Keele University , Stoke on Trent , UK
| | - Ying Yang
- Institute for Science and Technology in Medicine, School of Medicine, Keele University , Stoke on Trent , UK
| | - Clemens A van Blitterswijk
- Department of Tissue Regeneration, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands; Complex Tissue Regeneration Department, MERLN Institute for Technology Inspired Regenerative Medicine, University of Maastricht, Maastricht, Netherlands
| | - Nico Verdonschot
- Department of Biomechanical Engineering, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands; Orthopaedic Research Laboratory, Radboud Nijmegen Medical Centre, Nijmegen, Netherlands
| | - Lorenzo Moroni
- Department of Tissue Regeneration, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands; Complex Tissue Regeneration Department, MERLN Institute for Technology Inspired Regenerative Medicine, University of Maastricht, Maastricht, Netherlands
| | - Jeroen Rouwkema
- Department of Biomechanical Engineering, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente , Enschede , Netherlands
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