Impact of internal phase volume on the physical, morphological and mechanical characteristics of emulsion templated scaffolds

Year 2024, Volume: 10 Issue: 5, 522 - 532

Betül Aldemir Dikici

https://doi.org/10.18621/eurj.1518743

Abstract

Objectives: The high porosity of tissue engineering scaffolds is advantageous as they provide a high degree of infiltration of nutrients, enable cell penetration, and support vascularisation. However, the mechanical strength is also critical for providing structural support to the defect site throughout the regeneration process. In this study, we aimed to establish a relationship between internal phase volume and emulsion-templated scaffolds' physical, morphological and mechanical characteristics.

Methods: In this work, tetra methacrylate functionalised polycaprolactone (4PCLMA) polymers were synthesised via ring-opening polymerisation followed by methacrylation. 4PCLMA-based emulsion templated matrices with 60%, 75% and 82% internal phase volumes were fabricated (P60, P75, and P82). These scaffolds' densities, porosities, average pore and window sizes, degree of interconnectivity values, and mechanical properties were investigated.

Results: Increasing internal phase volume reduced the density of the foams by almost two-fold. No direct correlation was observed between average pore size and internal phase volume. Both the average window sizes and the degree of interconnectivity values increase with increasing internal phase volume. Compression modulus values are calculated as 0.46±0.04 MPa, 0.23±0.02 MPa and 0.14±0.01 MPa for P60, P75, and P82, respectively. Increasing internal phase volume from 60% to 82% caused a more than 2-fold reduction in the stiffness of the emulsion-templated matrices.

Conclusions: Accordingly, by reporting on this experimental framework, we established a relationship between internal phase volume and the physical, morphological and mechanical characteristics of 4PCMA-based scaffolds to precisely engineer these characteristics for specific tissue engineering applications.

Keywords

Biomaterials, emulsion templating, porosity, tissue engineering, mechanical characterization

Supporting Institution

This study was supported by the Department of Scientific Research Projects of Izmir Institute of Technology (IZTECH-BAP, 2021-IYTE-1-0110 and 2022- IYTE-2-0025), Health Institutes of Turkey (TUSEB-2022B02-22517).

Project Number

IZTECH-BAP: 2021-IYTE-1-0110 and 2022- IYTE-2-0025; TUSEB-2022B02-22517

References

• 1. Mert MS, Mert EH, Pulko I, Krajnc P, Mert HH. Form-stable oleic acid based polyHIPE/nanoclay framework supported composite phase change materials for low‐temperature latent heat storage. Therm Sci Eng Prog. 2024;50(5):102569. doi: 10.1016/j.tsep.2024.102569.
• 2. Silverstein MS. PolyHIPEs: Recent advances in emulsion-templated porous polymers. Prog Polym Sci. 2014;39(1):199-234. doi: 10.1016/j.progpolymsci.2013.07.003.
• 3. Kovacic S, Schafzahl B, Matsko NB, et al. Carbon Foams via Ring-Opening Metathesis Polymerization of Emulsion Templates: A Facile Method to Make Carbon Current Collectors for Battery Applications. ACS Appl Energy Mater. 2022;5(11):14381-14390. doi: 10.1021/acsaem.2c02787.
• 4. Zowada R, Foudazi R. Macroporous hydrogels for soil water retention in arid and semi-arid regions. RSC Appl Polym. 2023;1(2):243-253. doi: 10.1039/d3lp00117b.
• 5. Kovacic JM, Ciringer T, Ambrozic-Dolinsek J, Kovacic S. Use of Emulsion-Templated, Highly Porous Polyelectrolytes for In Vitro Germination of Chickpea Embryos: a New Substrate for Soilless Cultivation. Biomacromolecules. 2022;23(8):3452-3457. doi: 10.1021/acs.biomac.2c00593.
• 6. Mert EH, Kaya MA, Yildirim H. Preparation and characterization of polyester-glycidyl methacrylate polyHIPE monoliths to use in heavy metal removal. Des Monomers Polym. 2012;15(2):113-126. doi: 10.1163/156855511X615001.
• 7. Aldemir Dikici B, Claeyssens F. Basic Principles of Emulsion Templating and Its Use as an Emerging Manufacturing Method of Tissue Engineering Scaffolds. Front Bioeng Biotechnol. 2020;8:875. doi: 10.3389/fbioe.2020.00875.
• 8. Sears NA, Dhavalikar PS, Cosgriff-Hernandez EM. Emulsion Inks for 3D Printing of High Porosity Materials. Macromol Rapid Commun. 2016;37(16):1369-1374. doi: 10.1002/marc.201600236.
• 9. Moglia R, Whitely M, Brooks M, Robinson J, Pishko M, Cosgriff-Hernandez E. Solvent-free fabrication of polyHIPE microspheres for controlled release of growth factors. Macromol Rapid Commun. 2014;35(14):1301-1305. doi: 10.1002/marc.201400145.
• 10. Christenson EM, Soofi W, Holm JL, Cameron NR, Mikos AG. Biodegradable Fumarate-Based PolyHIPEs as Tissue Engineering Scaffolds. Biomacromolecules. 2007;8(12):3806-3814. doi: 10.1021/bm7007235.
• 11. Knight E, Murray B, Carnachan R, Przyborski S. Alvetex®: polystyrene scaffold technology for routine three dimensional cell culture. Methods Mol Biol. 2011;695:323-340. doi: 10.1007/978-1-60761-984-0_20.
• 12. Aldemir Dikici B. Development of emulsion templated matrices and their use in tissue engineering applications. The University of Sheffield, PhD thesis; 2020. Available from: https://etheses.whiterose.ac.uk/27827/
• 13. Langer R, Vacanti JP. Tissue engineering. Science. 1993;260(5110):920-926. doi: 10.1126/science.8493529.
• 14. Dikici S. Enhancing wound regeneration potential of fibroblasts using ascorbic acid-loaded decellularized baby spinach leaves. Polym Bull. 2024;81:9995-10016. doi: 10.1007/s00289-024-05185-1.
• 15. Tamburaci S, Tihminlioglu F. Development of Si doped nano hydroxyapatite reinforced bilayer chitosan nanocomposite barrier membranes for guided bone regeneration. Mater Sci Eng C Mater Biol Appl. 2021;128:112298. doi: 10.1016/j.msec.2021.112298.
• 16. Pashneh-Tala S, Moorehead R, Claeyssens F. Hybrid manufacturing strategies for tissue engineering scaffolds using methacrylate functionalised poly(glycerol sebacate). J Biomater Appl. 2020;34(8):1114-1130. doi: 10.1177/0885328219898385.
• 17. Owen R, Sherborne C, Evans R, Reilly GC, Claeyssens F. Combined Porogen Leaching and Emulsion Templating to produce Bone Tissue Engineering Scaffolds. Int J Bioprint. 2020;6(2):265. doi: 10.18063/ijb.v6i2.265.
• 18. Aldemir Dikici B, Chen M-C, Dikici S, Chiu H-C, Claeyssens F. In Vivo Bone Regeneration Capacity of Multiscale Porous Polycaprolactone-Based High Internal Phase Emulsion (PolyHIPE) Scaffolds in a Rat Calvarial Defect Model. ACS Appl Mater Interfaces. 2023;15(23):27696-27705. doi: 10.1021/acsami.3c04362.
• 19. Cameron NR. High internal phase emulsion templating as a route to well-defined porous polymers. Polymer. 2005;46(5):1439-1449. doi: 10.1016/j.polymer.2004.11.097.
• 20. Silverstein MS. Emulsion-templated porous polymers: A retrospective perspective. Polymer. 2014;55(1):304-320. doi: 10.1016/j.polymer.2013.08.068.
• 21. Zhang T, Sanguramath RA, Israel S, Silverstein MS. Emulsion Templating: Porous Polymers and beyond. Macromolecules. 2019;52(15):5445-5479. doi: 10.1021/acs.macromol.8b02576.
• 22. Pulko I, Krajnc P. High internal phase emulsion templating - A path to hierarchically porous functional polymers. Macromol Rapid Commun. 2012;33(20):1731-1746. doi: 10.1002/marc.201200393.
• 23. Aldemir Dikici B, Dikici S, Claeyssens F. Synergistic effect of type and concentration of surfactant and diluting solvent on the morphology of highly porous emulsion templated tissue engineering scaffolds. React Funct Polymers. 2022;180(11):105387. doi: 10.1016/j.reactfunctpolym.2022.105387.
• 24. Dhavalikar P, Shenoi J, Salhadar K, et al. Engineering Toolbox for Systematic Design of PolyHIPE Architecture. Polymers (Basel). 2021;13(9):1479. doi: 10.3390/polym13091479.
• 25. Sengokmen-Ozsoz N, Boston R, Claeyssens F. Investigating the Potential of Electroless Nickel Plating for Fabricating Ultra-Porous Metal-Based Lattice Structures Using PolyHIPE Templates. ACS Appl Mater Interfaces. 2023;15(25):30769-30779. doi: 10.1021/acsami.3c04637.
• 26. Barbetta A, Cameron NR. Morphology and surface area of emulsion-derived (PolyHIPE) solid foams prepared with oil-phase soluble porogenic solvents: Span 80 as surfactant. Macromolecules. 2004;37(9):3188-3201. doi: 10.1021/ma0359436.
• 27. Durgut E, Sherborne C, Aldemir Dikici B, Reilly GC, Claeyssens F. Preparation of Interconnected Pickering Polymerized High Internal Phase Emulsions by Arrested Coalescence. Langmuir. 2022;38(36):10953-10962. doi: 10.1021/acs.langmuir.2c01243.
• 28. McKenzie TJ, Ayres N. Synthesis and Applications of Elastomeric Polymerized High Internal Phase Emulsions (PolyHIPEs). ACS Omega. 2023;8(23):20178-20195. doi: 10.1021/acsomega.3c01265.
• 29. Guarino V, Causa F, Ambrosio L. Porosity and mechanical properties relationship in PCL porous scaffolds. J Appl Biomater Biomech. 2007;5(3):149-157. doi: 10.1177/228080000700500303.
• 30. Mert EH, Mert HH. Preparation of polyHIPE nanocomposites: Revealing the influence of experimental parameters with the help of experimental design approach. Polym Compos. 2021;42(2):724-738. doi: 10.1002/PC.25861.
• 31. Paterson TE, Gigliobianco G, Sherborne C, et al. Porous microspheres support mesenchymal progenitor cell ingrowth and stimulate angiogenesis. APL Bioeng. 2018;2(2):026103. doi: 10.1063/1.5008556.
• 32. Wang A, Paterson T, Owen R, et al. Photocurable high internal phase emulsions (HIPEs) containing hydroxyapatite for additive manufacture of tissue engineering scaffolds with multi-scale porosity. Mater Sci Eng C Mater Biol Appl. 2016;67:51-58. doi: 10.1016/j.msec.2016.04.087.
• 33. Owen R, Sherborne C, Paterson T, Green NH, Reilly GC, Claeyssens F. Emulsion templated scaffolds with tunable mechanical properties for bone tissue engineering. J Mech Behav Biomed Mater. 2016;54:159-172. doi: 10.1016/j.jmbbm.2015.09.019.
• 34. Woodruff MA, Hutmacher DW. The return of a forgotten polymer - Polycaprolactone in the 21st century. Prog Polym Sci (Oxford). 2010;35(10):1217-1256. doi: 10.1016/j.progpolymsci.2010.04.002.
• 35. Aldemir Dikici B, Sherborne C, Reilly GC, Claeyssens F. Emulsion templated scaffolds manufactured from photocurable polycaprolactone. Polymer (Guildf). 2019;175:243-254. doi: 10.1016/j.polymer.2019.05.023.
• 36. Aldemir Dikici B, Reilly GC, Claeyssens F. Boosting the Osteogenic and Angiogenic Performance of Multiscale Porous Polycaprolactone Scaffolds by In Vitro Generated Extracellular Matrix Decoration. ACS Appl Mater Interfaces. 2020;12(11):12510-12524. doi: 10.1021/acsami.9b23100.
• 37. Xu WF, Bai R, Zhang FA. Effects of internal-phase contents on porous polymers prepared by a high-internal-phase emulsion method. J Polym Res. 2014;21:524. doi: 10.1007/s10965-014-0524-2.
• 38. Karaca I, Aldemir Dikici B. Quantitative Evaluation of the Pore and Window Sizes of Tissue Engineering Scaffolds on Scanning Electron Microscope Images Using Deep Learning. ACS Omega. 2024;9(23):24695-24706. doi: 10.1021/acsomega.4c01234.
• 39. Jackson CE, Doyle I, Khan H, et al. Gelatin-containing porous polycaprolactone PolyHIPEs as substrates for 3D breast cancer cell culture and vascular infiltration. Front Bioeng Biotechnol. 2024;11:1321197. doi: 10.3389/fbioe.2023.1321197.
• 40. Kravchenko OG, Gedler G, Kravchenko SG, Feke DL, Manas-Zloczower I. Modeling compressive behavior of open-cell polymerized high internal phase emulsions: Effects of density and morphology. Soft Matter. 2018;14(9):1637-1646. doi: 10.1039/c7sm02043k.
• 41. Barbetta A, Dentini M, Zannoni EM, De Stefano ME. Tailoring the porosity and morphology of gelatin-methacrylate polyHIPE scaffolds for tissue engineering applications. Langmuir. 2005;21(26):12333-12341. doi: 10.1021/la0520233.
• 42. Hoque ME, San WY, Wei F, et al. Processing of polycaprolactone and polycaprolactone-based copolymers into 3D scaffolds, and their cellular responses. Tissue Eng Part A. 2009;15(10):3013-3024. doi: 10.1089/ten.TEA.2008.0355.
• 43. Aldemir Dikici B, Dikici S, Reilly GC, MacNeil S, Claeyssens F. A Novel Bilayer Polycaprolactone Membrane for Guided Bone Regeneration: Combining Electrospinning and Emulsion Templating. Materials (Basel). 2019;12(16):2643. doi: 10.3390/ma12162643.
• 44. Dikici S, Aldemir Dikici B, MacNeil S, Claeyssens F. Decellularised extracellular matrix decorated PCL PolyHIPE scaffolds for enhanced cellular activity, integration and angiogenesis. Biomater Sci. 2021;9(21):7297-7310. doi: 10.1039/d1bm01262b.