Composite Fibrin and Carbon Microfibre Implant to Modulate Postraumatic Inflammation after Spinal Cord Injury

Area of Science:

• Biomaterials Science
• Neuroscience
• Immunology

Background:

• Spinal cord injury (SCI) results in poor functional recovery, necessitating innovative therapeutic strategies.
• Previous research demonstrated immunomodulatory and pro-regenerative effects of bio-functionalized carbon microfibres (MFs) in rodent SCI models.

Purpose of the Study:

• To develop a composite implant combining MFs within a fibrin hydrogel for enhanced spinal cord repair and easier implantation.
• To investigate the neuroinflammatory response and axonal regeneration impact of the MF-fibrin hydrogel composite in a rodent SCI model.

Main Methods:

• Fabrication of a composite implant with MFs embedded in a fibrin hydrogel.
• Intravital imaging of fluorescent reporter mice to assess early-stage host response.
• Analysis of spinal sections at 3 months post-implantation to evaluate neuroinflammation and axonal regeneration.

Main Results:

• Fibrin hydrogel alone led to chronic microglial activation and axonal degeneration due to enzymatic degradation.
• The MF-fibrin hydrogel composite demonstrated slower fibrin degradation and enhanced early immune cell recruitment.
• An increased presence of monocyte-derived dendritic cells (moDCs) was observed, facilitating a shift to an anti-inflammatory environment and promoting axonal regeneration.

Conclusions:

• Embedding MFs within fibrin hydrogels significantly improves their long-term biocompatibility for spinal cord regeneration.
• The MF-fibrin hydrogel composite shows potential as a therapeutic strategy for enhancing functional recovery after SCI.