Chitosan implants in the rat spinal cord: biocompatibility and biodegradation

Area of Science:

• Biomaterials Science
• Neuroscience
• Tissue Engineering

Background:

• Biomaterials are crucial for spinal cord repair, but their long-term biocompatibility in the central nervous system is understudied.
• Investigating host tissue response and biodegradation is essential for selecting appropriate biomaterials.

Purpose of the Study:

• To compare the biocompatibility and biodegradation of chitosan with commercial biomaterials (vicryl and expanded poly(tetrafluoroethylene)) in rat spinal cord models.
• To evaluate the long-term suitability of chitosan for spinal cord repair applications.

Main Methods:

• Two rat spinal cord implantation models were used: intrathecal space (up to 6 months) and direct spinal cord implantation (up to 12 months).
• Host tissue response (macrophage/microglia activity, fibrous encapsulation) and material biodegradation (mass loss, SEM, histological staining) were assessed.

Main Results:

• Vicryl implants showed an initial elevated immune response that subsided by 6 months, with complete degradation.
• Expanded poly(tetrafluoroethylene) (Gore-Tex) exhibited no degradation and minimal chronic immune response.
• Chitosan demonstrated evidence of chain degradation without mass loss, indicating relative inertness and suitability for long-term use.

Conclusions:

• Chitosan is a relatively inert biomaterial for spinal cord repair, eliciting a minimal chronic immune response.
• Chitosan's degradation profile and biocompatibility make it suitable for long-term central nervous system tissue repair applications.
• The study provides valuable insights into biomaterial selection for spinal cord regeneration strategies.