Macro-architectures in spinal cord scaffold implants influence regeneration.
Biomaterial scaffold architecture has not been investigated as a tunable source of influence on spinal cord regeneration. This study compared regeneration in a transected spinal cord within various designed-macro-architecture scaffolds to determine if these architectures alone could enhance regeneration. Three-dimensional (3-D) designs were created and molds were built on a 3-D printer. Salt-leached porous poly(epsilon-caprolactone) was cast in five different macro-architectures: cylinder, tube, channel, open-path with core, and open-path without core. The two open-path designs were created in this experiment to compare different supportive aspects of architecture provided by scaffolds and their influence on regeneration. Rats received T8 transections and implanted scaffolds for 1 and 3 months. Overall morphology and orientation of sections were characterized by H&E, luxol fast blue, and cresyl violet staining. Borders between intact gray matter and non-regenerated defect were observed from GFAP immunolabeling. Nerve fibers and regenerating axons were identified with Tuj-1 immunolabeling. The open-path designs allowed extension of myelinated fibers along the length of the defect both exterior to and inside the scaffolds and maintained their original defect length up to 3 months. In contrast, the cylinder, tube, and channel implants had a doubling of defect length from secondary damage and large scar and cyst formation with no neural tissue bridging. The open-path scaffold architectures enhanced spinal cord regeneration compared to the three other designs without the use of biological factors.
Wong
Darice Y
DY
Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2106, USA.
Leveque
Jean-Christophe
JC
Brumblay
Hunter
H
Krebsbach
Paul H
PH
Hollister
Scott J
SJ
Lamarca
Frank
F
D000818:Animals; D001672:Biocompatible Materials; D005260:Female; D048091:Guided Tissue Regeneration / Q000295:instrumentation*; D011091:Polyesters; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000628:therapy*; D013904:Thoracic Vertebrae; D054457:Tissue Scaffolds
D001672:Biocompatible Materials; D011091:Polyesters; C016240:polycaprolactone