Exposure to buffer solution alters tendon hydration and mechanics.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Biomechanics

Background:

• Phosphate buffered saline (PBS) is commonly used for tissue hydration during mechanical testing.
• PBS can increase tissue water content, decrease stiffness, and introduce solute diffusion artifacts.
• These effects can confound mechanical test results and interpretations.

Purpose of the Study:

• To evaluate the impact of various buffer solutions on tissue hydration, solute diffusion, and mechanical properties.
• To compare the effects of different concentrations of NaCl, sucrose, polyethylene glycol (PEG), and SPEG (NaCl+PEG) on rat tail tendon fascicles.
• To identify suitable buffer solutions for long-term mechanical testing of tissues.

Main Methods:

• Rat tail tendon fascicles were exposed to varying concentrations (0.9-25%) of NaCl, sucrose, PEG, and SPEG solutions.
• Measurements included water content, solute diffusion, and mechanical properties (modulus, stress, cross-sectional area).
• Short-term (15 min) and long-term (8 h) incubation periods were assessed.

Main Results:

• Increasing solute concentration decreased apparent water content across all solution types.
• NaCl and sucrose solutions showed significant solute diffusion into the tissue.
• PEG and SPEG solutions prevented solute diffusion and maintained consistent mechanical properties, unlike NaCl solutions which showed altered mechanical responses.

Conclusions:

• NaCl and sucrose are unsuitable for long-term mechanical testing due to hydration and mechanical property alterations.
• PEG and SPEG are proposed as superior alternatives for maintaining tissue hydration and mechanical integrity.
• These findings provide crucial insights for selecting appropriate buffer solutions in biomechanical studies.