TY - JOUR
T1 - Comparison of macroscale and microscale mechanical properties of fresh and fixed-frozen porcine colonic tissue
AU - McCarthy, Clíona M.
AU - Allardyce, Joanna M.
AU - Hickey, Séamus E.
AU - Walsh, Michael T.
AU - McGourty, Kieran D.
AU - Mulvihill, John J.E.
N1 - Publisher Copyright:
© 2022
PY - 2023/2
Y1 - 2023/2
N2 - Mechanical changes to the microenvironment of the extracellular matrix (ECM) in tissue have been hypothesised to elicit a pathogenic response in the surrounding cells. Hence, 3D scaffolds are a popular method of studying cellular behaviour under conditions that mimic in vivo microenvironment. To create a 3D biomimetic scaffold that captures the in vivo ECM microenvironment a robust mechanical characterisation of the whole ECM at the microscale is necessary. This study examined the multiscale methods of characterising the ECM microenvironment using porcine colon tissue. To facilitate fresh tissue microscale mechanical characterisation, a protocol for sectioning fresh, unfixed, soft biological tissue was developed. Four experiments examined both the microscale and macroscale mechanics of both fresh (Fr) and fixed-frozen (FF) porcine colonic tissue using microindentation for microscale testing and uniaxial compression testing for macroscale testing. The results obtained in this study show a significant difference in elastic modulus between Fr and FF tissue at both the macroscale and microscale. There was an order of magnitude difference between the Fr and FF tissue at the microscale between each of the three layers of the colon tested i.e. the muscularis propria (MP), the submucosa (SM) and the mucosa (M). Macroscale testing cannot capture these regional differences. The findings in this study suggest that the most appropriate method for mechanically characterising the ECM is fresh microscale mechanical microindentation. These methods can be used on a range of biological tissues to create 3D biomimetic scaffolds that are more representative of the in vivo ECM, allowing for a more in-depth characterisation of the disease process.
AB - Mechanical changes to the microenvironment of the extracellular matrix (ECM) in tissue have been hypothesised to elicit a pathogenic response in the surrounding cells. Hence, 3D scaffolds are a popular method of studying cellular behaviour under conditions that mimic in vivo microenvironment. To create a 3D biomimetic scaffold that captures the in vivo ECM microenvironment a robust mechanical characterisation of the whole ECM at the microscale is necessary. This study examined the multiscale methods of characterising the ECM microenvironment using porcine colon tissue. To facilitate fresh tissue microscale mechanical characterisation, a protocol for sectioning fresh, unfixed, soft biological tissue was developed. Four experiments examined both the microscale and macroscale mechanics of both fresh (Fr) and fixed-frozen (FF) porcine colonic tissue using microindentation for microscale testing and uniaxial compression testing for macroscale testing. The results obtained in this study show a significant difference in elastic modulus between Fr and FF tissue at both the macroscale and microscale. There was an order of magnitude difference between the Fr and FF tissue at the microscale between each of the three layers of the colon tested i.e. the muscularis propria (MP), the submucosa (SM) and the mucosa (M). Macroscale testing cannot capture these regional differences. The findings in this study suggest that the most appropriate method for mechanically characterising the ECM is fresh microscale mechanical microindentation. These methods can be used on a range of biological tissues to create 3D biomimetic scaffolds that are more representative of the in vivo ECM, allowing for a more in-depth characterisation of the disease process.
KW - Fresh tissue sectioning
KW - Histology
KW - Mechanical characterization
KW - Microscale testing
KW - Mucosal tissue layers
KW - Soft biological tissue
KW - Uniaxial compression testing
UR - http://www.scopus.com/inward/record.url?scp=85146242515&partnerID=8YFLogxK
U2 - 10.1016/j.jmbbm.2022.105599
DO - 10.1016/j.jmbbm.2022.105599
M3 - Article
C2 - 36462287
AN - SCOPUS:85146242515
SN - 1751-6161
VL - 138
SP - 105599
JO - Journal of the Mechanical Behavior of Biomedical Materials
JF - Journal of the Mechanical Behavior of Biomedical Materials
M1 - 105599
ER -