Optimizing Design Parameters of PLA 3D-Printed Scaffolds for Bone Defect Repair
Current materials used to fill bone defects (ceramics, cement) either lack strength or do not induce bone repair. The use of biodegradable polymers such as PLA may promote patient healing by stimulating the production of new bone in parallel with a controlled degradation of the scaffold. This projec...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-06-01
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| Series: | Surgeries |
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| Online Access: | https://www.mdpi.com/2673-4095/3/3/18 |
| _version_ | 1797482282365222912 |
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| author | Alexandrine Dussault Audrey A. Pitaru Michael H. Weber Lisbet Haglund Derek H. Rosenzweig Isabelle Villemure |
| author_facet | Alexandrine Dussault Audrey A. Pitaru Michael H. Weber Lisbet Haglund Derek H. Rosenzweig Isabelle Villemure |
| author_sort | Alexandrine Dussault |
| collection | DOAJ |
| description | Current materials used to fill bone defects (ceramics, cement) either lack strength or do not induce bone repair. The use of biodegradable polymers such as PLA may promote patient healing by stimulating the production of new bone in parallel with a controlled degradation of the scaffold. This project aims to determine the design parameters maximising scaffold mechanical performance in such materials. Starting from a base cylindrical model of 10 mm height and of outer and inner diameters of 10 and 4 mm, respectively, 27 scaffolds were designed. Three design parameters were investigated: pore distribution (crosswise, lengthwise, and eccentric), pore shape (triangular, circular, and square), and pore size (surface area of 0.25 mm<sup>2</sup>, 0.5625 mm<sup>2</sup>, and 1 mm<sup>2</sup>). Using the finite element approach, a compressive <i>displacement</i> (0.05 mm/s up to 15% <i>strain</i>) was simulated on the models and the resulting scaffold stiffnesses (N/mm<sup>2</sup>) were compared. The models presenting good mechanical behaviors were further printed along two orientations: 0° (cylinder sitting on its base) and 90° (cylinder laying on its side). A total of <i>n</i> = 5 specimens were printed with PLA for each of the retained models and experimentally tested using a mechanical testing machine with the same compression parameters. Rigidity and yield strength were evaluated from the experimental curves. Both numerically and experimentally, the highest rigidity was found in the model with circular pore shape, crosswise pore distribution, small pore size (surface area of 0.25 mm<sup>2</sup>), and a 90° printing orientation. Its average rigidity reached 961 ± 32 MPa from the mechanical testing and 797 MPa from the simulation, with a yield strength of 42 ± 1.5 MPa. The same model with a printing orientation of 0° resulted in an average rigidity of 515 ± 7 MPa with a yield strength of 32 ± 1.6 MPa. Printing orientation and pore size were found to be the most influential design parameters on rigidity. The developed design methodology should accelerate the identification of effective scaffolds for future in vitro and in vivo studies. |
| first_indexed | 2024-03-09T22:30:01Z |
| format | Article |
| id | doaj.art-90c13fff59624c01aa03e4e14456bbd8 |
| institution | Directory Open Access Journal |
| issn | 2673-4095 |
| language | English |
| last_indexed | 2024-03-09T22:30:01Z |
| publishDate | 2022-06-01 |
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| series | Surgeries |
| spelling | doaj.art-90c13fff59624c01aa03e4e14456bbd82023-11-23T18:58:16ZengMDPI AGSurgeries2673-40952022-06-013316217410.3390/surgeries3030018Optimizing Design Parameters of PLA 3D-Printed Scaffolds for Bone Defect RepairAlexandrine Dussault0Audrey A. Pitaru1Michael H. Weber2Lisbet Haglund3Derek H. Rosenzweig4Isabelle Villemure5Polytechnique Montréal, Montreal, QC H3C 3A7, CanadaExperimental Surgery, McGill University, Montreal, QC H3A 0G4, CanadaDepartment of Surgery, Montreal General Hospital, McGill University, Montreal, QC H3G 1A4, CanadaDepartment of Surgery, Montreal General Hospital, McGill University, Montreal, QC H3G 1A4, CanadaDepartment of Surgery, Montreal General Hospital, McGill University, Montreal, QC H3G 1A4, CanadaPolytechnique Montréal, CHU Sainte-Justine, Montréal, QC H3T 1J4, CanadaCurrent materials used to fill bone defects (ceramics, cement) either lack strength or do not induce bone repair. The use of biodegradable polymers such as PLA may promote patient healing by stimulating the production of new bone in parallel with a controlled degradation of the scaffold. This project aims to determine the design parameters maximising scaffold mechanical performance in such materials. Starting from a base cylindrical model of 10 mm height and of outer and inner diameters of 10 and 4 mm, respectively, 27 scaffolds were designed. Three design parameters were investigated: pore distribution (crosswise, lengthwise, and eccentric), pore shape (triangular, circular, and square), and pore size (surface area of 0.25 mm<sup>2</sup>, 0.5625 mm<sup>2</sup>, and 1 mm<sup>2</sup>). Using the finite element approach, a compressive <i>displacement</i> (0.05 mm/s up to 15% <i>strain</i>) was simulated on the models and the resulting scaffold stiffnesses (N/mm<sup>2</sup>) were compared. The models presenting good mechanical behaviors were further printed along two orientations: 0° (cylinder sitting on its base) and 90° (cylinder laying on its side). A total of <i>n</i> = 5 specimens were printed with PLA for each of the retained models and experimentally tested using a mechanical testing machine with the same compression parameters. Rigidity and yield strength were evaluated from the experimental curves. Both numerically and experimentally, the highest rigidity was found in the model with circular pore shape, crosswise pore distribution, small pore size (surface area of 0.25 mm<sup>2</sup>), and a 90° printing orientation. Its average rigidity reached 961 ± 32 MPa from the mechanical testing and 797 MPa from the simulation, with a yield strength of 42 ± 1.5 MPa. The same model with a printing orientation of 0° resulted in an average rigidity of 515 ± 7 MPa with a yield strength of 32 ± 1.6 MPa. Printing orientation and pore size were found to be the most influential design parameters on rigidity. The developed design methodology should accelerate the identification of effective scaffolds for future in vitro and in vivo studies.https://www.mdpi.com/2673-4095/3/3/18scaffolds3D-printingscaffolds designbone resectionbone replacementPLA |
| spellingShingle | Alexandrine Dussault Audrey A. Pitaru Michael H. Weber Lisbet Haglund Derek H. Rosenzweig Isabelle Villemure Optimizing Design Parameters of PLA 3D-Printed Scaffolds for Bone Defect Repair Surgeries scaffolds 3D-printing scaffolds design bone resection bone replacement PLA |
| title | Optimizing Design Parameters of PLA 3D-Printed Scaffolds for Bone Defect Repair |
| title_full | Optimizing Design Parameters of PLA 3D-Printed Scaffolds for Bone Defect Repair |
| title_fullStr | Optimizing Design Parameters of PLA 3D-Printed Scaffolds for Bone Defect Repair |
| title_full_unstemmed | Optimizing Design Parameters of PLA 3D-Printed Scaffolds for Bone Defect Repair |
| title_short | Optimizing Design Parameters of PLA 3D-Printed Scaffolds for Bone Defect Repair |
| title_sort | optimizing design parameters of pla 3d printed scaffolds for bone defect repair |
| topic | scaffolds 3D-printing scaffolds design bone resection bone replacement PLA |
| url | https://www.mdpi.com/2673-4095/3/3/18 |
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