Type I collagen
Type I collagen is the most abundant collagen of the human body which forms large, eosinophilic fibers known as collagen fibers. It is present in scar tissue, the end product when tissue heals by repair, as well as tendons, ligaments, the endomysium of myofibrils, the organic part of bone, the dermis, the dentin and organ capsules.
Type I collagen accounts for nearly 70% of the dry weight of the outer annulus fibrosus (AF), with type II collagen gradually increasing and type I collagen decreasing from the outer to inner AF 1).
Mackenzie et al. transected cauda equina ventral roots and proceeded to bridge the proximal and distal stumps with either a type I collagen scaffold coated in laminin (CL) or a collagen-laminin scaffold that was also seeded with Schwann cells (CLSC). Regeneration was assessed by way of serial retrograde labeling.
After accounting for the axonal contributions to intrinsic vs extrinsic tail muscles, they noted a higher degree of double labeling in the CLSC group (58.0 ± 39.6%) as compared to the CL group (27.8 ± 16.0%; p = 0.02), but not the control group (33.5 ± 18.2%; p = 0.10).
The findings demonstrate the feasibility of using Schwann cell seeded collagen-laminin scaffolds in cauda equina injury repair 2).