Related Experiment Videos
Tapping-mode atomic force microscopy in fluid of hydrated extracellular matrix
M Raspanti1, T Congiu, S Guizzardi
1Laboratory of Human Morphology, Medical Faculty, Via Monte Generoso, 71, 21100 Varese, Italy. mario.raspanti@uninsubria.it
Summary
Atomic force microscopy revealed the detailed structure of collagen fibrils in hydrated rat tail tendon. Increased imaging pressure uncovered the D-period and subfibrils, offering insights into tendon architecture.
Area of Science:
- Biophysics
- Materials Science
- Biomaterials
Background:
- Tendon's mechanical properties depend on collagen fibril organization.
- Understanding collagen fibril ultrastructure is crucial for biomaterial development and regenerative medicine.
Purpose of the Study:
- To visualize the native, hydrated structure of collagen fibrils using atomic force microscopy.
- To investigate the impact of imaging parameters on fibril visualization.
- To identify internal structural features of collagen fibrils.
Main Methods:
- Tapping-mode atomic force microscopy (AFM) was employed to image hydrated rat tail tendon fragments.
- Imaging was performed in fluid to maintain sample hydration and native state.
- AFM operating parameters, specifically imaging pressure, were systematically varied.
Main Results:
- Collagen fibrils exhibited an evident D-period, gap- and overlap-zones, and three intraperiod ridges upon optimized imaging pressure.
- Longitudinal subfibrils, approximately 8-9 nm in thickness, were identified within the fibrils.
- Simultaneous acquisition of tapping amplitude and height channels confirmed the presence of these subfibrils.
Conclusions:
- Atomic force microscopy can resolve the intricate internal architecture of collagen fibrils in their native, hydrated state.
- The identified subfibrils provide new insights into the hierarchical structure of collagen.
- These findings contribute to a better understanding of tendon biomechanics and collagen-based biomaterials.