TY - JOUR
T1 - Physiochemical effects of acid exposure on bone composition and function
AU - Easson, Margaret
AU - Wong, Stephanie
AU - Moody, Mikayla
AU - Schmidt, Tannin A.
AU - Deymier, Alix
N1 - Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2024/2
Y1 - 2024/2
N2 - Bone is primarily composed of collagen and apatite, two materials which exhibit a high sensitivity to pH dysregulation. As a result, acid exposure of bone, both clinically and in the laboratory is expected to cause compositional and mechanical changes to the tissue. Clinically, Metabolic acidosis (MA), a condition characterized by a reduced physiological pH, has been shown to have negative implications on bone health, including a decrease in bone mineral density and volume as well as increased fracture risk. The addition of bone-like apatite to ionic solutions such as phosphate buffered saline (PBS) and media has been shown to acidify the solution leading to bone acid exposure. Therefore, is it essential to understand how reduced pH physiochemically affects bone composition and in turn its mechanical properties. This study investigates the specific changes in bone due to physiochemical dissolution in acid. Excised murine bones were placed in PBS solutions at different pHs: a homeostatic pH level (pH 7.4), an acidosis equivalent (pH 7.0), and an extreme acidic solution (pH 5.5). After 5 days, the bones were removed from the solutions and characterized to determine compositional and material changes. We found that bones, without cells, were able to regulate pH via buffering, leading to a decrease in bone mineral content and an increase in collagen denaturation. Both of these compositional changes contributed to an increase in bone toughness by creating a more ductile bone surface and preventing crack propagation. Therefore, we conclude that the skeletal systems’ physiochemical response to acid exposure includes multifaceted and spatially variable compositional changes that affect bone mechanics.
AB - Bone is primarily composed of collagen and apatite, two materials which exhibit a high sensitivity to pH dysregulation. As a result, acid exposure of bone, both clinically and in the laboratory is expected to cause compositional and mechanical changes to the tissue. Clinically, Metabolic acidosis (MA), a condition characterized by a reduced physiological pH, has been shown to have negative implications on bone health, including a decrease in bone mineral density and volume as well as increased fracture risk. The addition of bone-like apatite to ionic solutions such as phosphate buffered saline (PBS) and media has been shown to acidify the solution leading to bone acid exposure. Therefore, is it essential to understand how reduced pH physiochemically affects bone composition and in turn its mechanical properties. This study investigates the specific changes in bone due to physiochemical dissolution in acid. Excised murine bones were placed in PBS solutions at different pHs: a homeostatic pH level (pH 7.4), an acidosis equivalent (pH 7.0), and an extreme acidic solution (pH 5.5). After 5 days, the bones were removed from the solutions and characterized to determine compositional and material changes. We found that bones, without cells, were able to regulate pH via buffering, leading to a decrease in bone mineral content and an increase in collagen denaturation. Both of these compositional changes contributed to an increase in bone toughness by creating a more ductile bone surface and preventing crack propagation. Therefore, we conclude that the skeletal systems’ physiochemical response to acid exposure includes multifaceted and spatially variable compositional changes that affect bone mechanics.
KW - Acidosis
KW - Biomechanics
KW - Bone composition
KW - Bone mineral
KW - Physiochemical
UR - http://www.scopus.com/inward/record.url?scp=85179848775&partnerID=8YFLogxK
U2 - 10.1016/j.jmbbm.2023.106304
DO - 10.1016/j.jmbbm.2023.106304
M3 - Article
C2 - 38096610
AN - SCOPUS:85179848775
SN - 1751-6161
VL - 150
JO - Journal of the Mechanical Behavior of Biomedical Materials
JF - Journal of the Mechanical Behavior of Biomedical Materials
M1 - 106304
ER -