Collagen type II dynamics and assembly in anisotropic porous polyacrylamide hydrogels

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Polymer Science

Background:

• Natural biological tissues exhibit hierarchical organization and liquid crystallinity in their extracellular matrix (ECM).
• Recreating the complex architecture of the ECM is crucial for developing functional tissue engineering scaffolds.
• Anisotropic materials can direct cellular behavior and tissue development.

Purpose of the Study:

• To fabricate anisotropic polyacrylamide (PAAm) networks templated by disodium cromoglycate (DSCG) liquid crystal phases.
• To investigate the ability of these PAAm networks to guide collagen fiber alignment for biomimetic ECM formation.
• To understand how varying network properties influence collagen self-assembly and organization.

Main Methods:

• Fabrication of anisotropic PAAm networks via templated polymerization using DSCG liquid crystal phases.
• Tuning PAAm network modulus and polymerization temperature to control pore morphology and anisotropy.
• Characterization of network architecture using confocal microscopy.
• Assessment of collagen fibril formation, localization, and dynamics within the scaffolds using confocal microscopy and differential dynamic microscopy (DDM).

Main Results:

• Anisotropic PAAm networks were successfully fabricated, with pore morphology tunable by network modulus and polymerization temperature.
• Collagen fibers aligned within the anisotropic pores, recapitulating aspects of ECM organization.
• Collagen localization and mobility were dependent on scaffold architecture and polymerization conditions.
• Gels polymerized at -20 °C showed collagen freely diffusing and assembling into highly aligned structures within anisotropic pores.

Conclusions:

• Templated polymerization using liquid crystals provides a strategy for engineering biomimetic ECM scaffolds.
• The developed scaffolds can guide collagen self-assembly, offering potential for advanced tissue engineering applications.
• Understanding self-assembly in crowded, elastic environments is key to designing functional biomaterials.