Electromechanical Coupling in Collagen Measured under Increasing Relative Humidity

Area of Science:

• Biomaterials Science
• Nanotechnology
• Biophysics

Background:

• The piezoelectricity of collagen, a key component of bone, is debated, especially in humid physiological environments.
• Previous studies show conflicting results regarding collagen's piezoelectric behavior in hydrated versus dehydrated states.
• Nanoscale investigations using piezoresponse force microscopy (PFM) have detected piezoelectricity in both dry and wet bone.

Purpose of the Study:

• To investigate the nanoscale electromechanical properties of type I collagen as a function of humidity.
• To determine if collagen exhibits piezoelectric behavior under biologically relevant humidity levels.

Main Methods:

• Utilized lateral piezoresponse force microscopy (LPFM) to measure electromechanical properties.
• Investigated rat tail tendon type I collagen across a relative humidity (RH) range of 10% to 70%.
• Studied collagen in dry, humid, and hydrated states, including conditions mimicking physiological bone moisture (40-50% RH).

Main Results:

• Collagen's piezoresponse was measurable across the entire studied humidity range (10-70% RH).
• Piezoelectric behavior was observed in dry, humid, and hydrated collagen samples.
• Results indicate that collagen maintains its piezoelectric properties at biologically relevant humidity levels.

Conclusions:

• Collagen piezoelectricity is present across a wide range of humidity conditions.
• The findings suggest that collagen's piezoelectric properties are maintained at biologically relevant moisture levels.
• This supports the potential functional role of collagen piezoelectricity in physiological processes like bone remodeling.