Collagen microarchitecture from polarized light imaging: a biomechanics perspective

Area of Science:

• Biomedical Engineering
• Biophysics
• Materials Science

Background:

• Collagen is the primary load-bearing biopolymer in animal tissues, self-assembling into diverse microstructures like fibrils, fibers, bundles, and lamellae.
• Collagen's specific microstructure dictates tissue-specific mechanical properties, making visualization crucial for biomechanical understanding.
• Understanding collagen organization is essential for fields ranging from tissue engineering to disease diagnostics.

Purpose of the Study:

• To provide a foundational understanding of polarized light imaging methodologies.
• To elucidate how these techniques can be applied to characterize collagen microstructure.
• To bridge the gap between collagen structure and tissue biomechanics.

Main Methods:

• Review of polarized light principles and collagen's interaction with polarized light.
• Detailed description of various polarized light microscopy techniques, including instant polarized light microscopy.
• Exploration of advanced methods such as polarization-sensitive optical coherence tomography and polarization-resolved second-harmonic generation microscopy.

Main Results:

• Presentation of diverse methods for imaging collagen microstructure using polarized light.
• Coverage extends from *in vivo* imaging to high-resolution volumetric analysis of tissue sections.
• Demonstration of polarized light's utility in revealing collagen fiber orientation and network architecture.

Conclusions:

• Polarized light imaging offers powerful tools for investigating collagen microstructure.
• This review aims to equip researchers with the knowledge to utilize these techniques for studying collagen-biomechanics relationships.
• Enhanced understanding of collagen's role in tissue function and disease is facilitated by these advanced imaging modalities.