Macro-architectures in spinal cord scaffold implants influence regeneration

Area of Science:

• Biomaterials Science
• Neuroscience
• Regenerative Medicine

Background:

• Spinal cord regeneration research often focuses on biological factors.
• The role of biomaterial scaffold macro-architecture in spinal cord regeneration remains under-explored.

Purpose of the Study:

• To investigate if designed macro-architectures of biomaterial scaffolds alone can enhance spinal cord regeneration after transection.
• To compare the regenerative outcomes in different scaffold macro-architectures.

Main Methods:

• Created five 3-D printed macro-architectures (cylinder, tube, channel, open-path with core, open-path without core) using salt-leached porous poly(epsilon-caprolactone).
• Implanted scaffolds into rat T8 spinal cord transections for 1 and 3 months.
• Evaluated regeneration using histological staining (H&E, luxol fast blue, cresyl violet) and immunolabeling (GFAP, Tuj-1).

Main Results:

• Open-path scaffold designs facilitated the extension of myelinated nerve fibers within and along the defect, preserving original defect length up to 3 months.
• In contrast, cylinder, tube, and channel scaffolds resulted in increased defect length, scar formation, and cyst development, with no neural tissue bridging.
• The open-path architectures enhanced spinal cord regeneration without the need for biological augmentation.

Conclusions:

• Biomaterial scaffold macro-architecture is a critical, tunable factor influencing spinal cord regeneration.
• Open-path scaffold designs represent a promising strategy for promoting neural regeneration and reducing secondary damage in spinal cord injuries.
• Scaffold design, independent of biological additives, can significantly impact regenerative outcomes.