Early pH Changes in Musculoskeletal Tissues upon Injury-Aerobic Catabolic Pathway Activity Linked to Inter-Individual...

Area of Science:

• Biomedical Engineering
• Orthopedics
• Regenerative Medicine

Background:

• Local pH changes are known to occur after bone fracture, but the kinetics and extent are unclear.
• It is unknown if pH acidification in fracture hematomas extends to adjacent muscle hematomas or is unique to bone healing.

Purpose of the Study:

• To investigate the in vivo pH changes in bone and muscle hematomas during the early phase after musculoskeletal injury.
• To determine the extent and pattern of acidification in preclinical models.

Main Methods:

• Simultaneous in vivo pH measurements in sheep and rat models post-fracture and muscle trauma (up to 48 hours).
• Histological and metabolomic analysis of rat fracture hematomas.
• In vivo pH monitoring in bone and muscle hematomas.

Main Results:

• Local acidification was observed in both bone and muscle hematomas in both animal models.
• Mean pH values in rat hematomas were 6.69 (bone) and 6.89 (muscle), with significant variations.
• Metabolomic data suggested a correlation between reduced tricarboxylic acid cycle activity and pH, indicating metabolic activity as a potential cause.

Conclusions:

• Early musculoskeletal hematomas exhibit significant local acidification.
• The observed pH changes are linked to metabolic processes within the injured tissue.
• This early acidification presents a potential target for developing novel therapies with spatially and temporally controlled drug release.