A combinatorial approach for spinal cord injury repair using multifunctional collagen-based matrices: development, characterization and impact on cell adhesion and axonal growth

Spinal cord injury (SCI) is a devastating condition of the central nervous system (CNS), in which traditional treatments are largely ineffective due to the complex nature of the injured tissue. Therefore, biomaterial-based systems have been developed as possible alternative strategies to repair the damaged tissue. In the present study, we aimed to design bioactive agents loaded scaffolds composed of two layers with distinct physical properties to improve tissue regeneration. An electrospun layer with aligned nanofibers was made of collagen Type-I, poly(lactide-co-glycolide) and laminin to promote cell attachment of mesenchymal-like stem cells toward the direction of the fibers while collagen-based second layer fabricated by a plastic compression to acts as a releasing system for NT-3 and ChABC, so axonal growth could be stimulated. Results showed that a source of MSC-like cells, Adipose Tissue derived Stem Cells (ASCs) cultured on the fibrous layer of the matrices were able to adhere and proliferate, where the aligned fibers promoted the cell growth in an organized way. Furthermore, the bilayered matrices also promoted DRGs neurite outgrowth. The bilayered matrice with Col/PLGA+laminin top layer appears to promote higher neurite growth. Collectively, the designed constructs show promising the structural properties and biological performance for being employed as a scaffold for engineering the spinal cord tissue.