TY - JOUR
T1 - Load-induced fluid pressurisation in hydrogel systems before and after reinforcement by melt-electrowritten fibrous meshes
AU - Moo, Eng Kuan
AU - Ebrahimi, Mohammadhossein
AU - Hrynevich, Andrei
AU - de Ruijter, Mylène
AU - Castilho, Miguel
AU - Malda, Jos
AU - Korhonen, Rami K.
N1 - Funding Information:
We would like to acknowledge the financial supports from the Marie Skłodowska-Curie Actions postdoctoral fellowship (project number: 890936 ), Academy of Finland (grant 324529 ), the Dutch Arthritis Society ( LLP-12 and LLP-22 ), the Gravitation Program “Materials Driven Regeneration”, funded by the Netherlands Organization for Scientific Research ( 024.003.013 ), the Reprint project ( OCENW.XS5.161 ) funded by the Netherlands Organization for Scientific Research, and the Carleton University internal research start-up fund ( 186725 ).
Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/7
Y1 - 2023/7
N2 - Fluid pressure develops transiently within mechanically-loaded, cell-embedding hydrogels, but its magnitude depends on the intrinsic material properties of the hydrogel and cannot be easily altered. The recently developed melt-electrowriting (MEW) technique enables three-dimensional printing of structured fibrous mesh with small fibre diameter (20 μm). The MEW mesh with 20 μm fibre diameter can synergistically increase the instantaneous mechanical stiffness of soft hydrogels. However, the reinforcing mechanism of the MEW meshes is not well understood, and may involve load-induced fluid pressurisation. Here, we examined the reinforcing effect of MEW meshes in three hydrogels: gelatin methacryloyl (GelMA), agarose and alginate, and the role of load-induced fluid pressurisation in the MEW reinforcement. We tested the hydrogels with and without MEW mesh (i.e., hydrogel alone, and MEW-hydrogel composite) using micro-indentation and unconfined compression, and analysed the mechanical data using biphasic Hertz and mixture models. We found that the MEW mesh altered the tension-to-compression modulus ratio differently for hydrogels that are cross-linked differently, which led to a variable change to their load-induced fluid pressurisation. MEW meshes only enhanced the fluid pressurisation for GelMA, but not for agarose or alginate. We speculate that only covalently cross-linked hydrogels (GelMA) can effectively tense the MEW meshes, thereby enhancing the fluid pressure developed during compressive loading. In conclusion, load-induced fluid pressurisation in selected hydrogels was enhanced by MEW fibrous mesh, and may be controlled by MEW mesh of different designs in the future, thereby making fluid pressure a tunable cell growth stimulus for tissue engineering involving mechanical stimulation.
AB - Fluid pressure develops transiently within mechanically-loaded, cell-embedding hydrogels, but its magnitude depends on the intrinsic material properties of the hydrogel and cannot be easily altered. The recently developed melt-electrowriting (MEW) technique enables three-dimensional printing of structured fibrous mesh with small fibre diameter (20 μm). The MEW mesh with 20 μm fibre diameter can synergistically increase the instantaneous mechanical stiffness of soft hydrogels. However, the reinforcing mechanism of the MEW meshes is not well understood, and may involve load-induced fluid pressurisation. Here, we examined the reinforcing effect of MEW meshes in three hydrogels: gelatin methacryloyl (GelMA), agarose and alginate, and the role of load-induced fluid pressurisation in the MEW reinforcement. We tested the hydrogels with and without MEW mesh (i.e., hydrogel alone, and MEW-hydrogel composite) using micro-indentation and unconfined compression, and analysed the mechanical data using biphasic Hertz and mixture models. We found that the MEW mesh altered the tension-to-compression modulus ratio differently for hydrogels that are cross-linked differently, which led to a variable change to their load-induced fluid pressurisation. MEW meshes only enhanced the fluid pressurisation for GelMA, but not for agarose or alginate. We speculate that only covalently cross-linked hydrogels (GelMA) can effectively tense the MEW meshes, thereby enhancing the fluid pressure developed during compressive loading. In conclusion, load-induced fluid pressurisation in selected hydrogels was enhanced by MEW fibrous mesh, and may be controlled by MEW mesh of different designs in the future, thereby making fluid pressure a tunable cell growth stimulus for tissue engineering involving mechanical stimulation.
KW - Agarose
KW - Alginate
KW - Fluid load support
KW - Gelatin methacryloyl
KW - Micro-indentation
KW - Poroelasticity
KW - Reinforced scaffolds
KW - Unconfined compression
KW - Viscoelasticity
UR - http://www.scopus.com/inward/record.url?scp=85160843595&partnerID=8YFLogxK
U2 - 10.1016/j.jmbbm.2023.105941
DO - 10.1016/j.jmbbm.2023.105941
M3 - Article
C2 - 37285774
AN - SCOPUS:85160843595
SN - 1751-6161
VL - 143
JO - Journal of the mechanical behavior of biomedical materials
JF - Journal of the mechanical behavior of biomedical materials
M1 - 105941
ER -