Peripheral mineralization of a 3D biodegradable tubular construct as a way to enhance guidance stabilization in spinal cord injury regeneration
- 648 Downloads
Spinal cord injuries (SCI) present a major challenge to therapeutic development due to its complexity. Combinatorial approaches using biodegradable polymers that can simultaneously provide a tissue scaffold, a cell vehicle, and a reservoir for sustained drug delivery have shown very promising results. In our previous studies we have developed a novel hybrid system consisting of starch/poly-e-caprolactone (SPCL) semi-rigid tubular porous structure, based on a rapid prototyping technology, filled by a gellan gum hydrogel concentric core for the regeneration within spinal-cord injury sites. In the present work we intend to promote enhanced osteointegration on these systems by pre-mineralizing specifically the external surfaces of the SPCL tubular structures, though a biomimetic strategy, using a sodium silicate gel as nucleating agent. The idea is to create two different cell environments to promote axonal regeneration in the interior of the constructs while inducing osteogenic activity on its external surface. By using a Teflon cylinder to isolate the interior of the scaffold, it was possible to observe the formation of a bone-like poorly crystalline carbonated apatite layer continuously formed only in the external side of the tubular structure. This biomimetic layer was able to support the adhesion of Bone Marrow Mesenchymal Stem Cells, which have gone under cytoskeleton reorganization in the first hours of culture when compared to cells cultured on uncoated scaffolds. This strategy can be a useful route for locally stimulate bone tissue regeneration and facilitating early bone ingrowth.
KeywordsApatite Simulated Body Fluid Simulated Body Fluid Solution Apatite Layer Spinal Cord Injury
Portuguese Foundation for Science and Technology under POCTI and/or FEDER programs (pre-doctoral fellowship to Nuno A. Silva, SFRH/BD/40684/2007, post-doctoral fellowship to Ana L. Oliveira, SFRH/BPD/39102/2007, and Ciência 2007 Program to António J. Salgado); Foundation Calouste de Gulbenkian to funds attributed to António J. Salgado under the scope of the Gulbenkian Programme to Support Research in the Life Sciences.
- 10.Hejcl A, Lesny P, Pradny M, Michalek J, Jendelova P, Stulik J, et al. Biocompatible hydrogels in spinal cord injury repair. Physiol Res. 2008;57:S121–32.Google Scholar
- 13.Silva NA, Salgado AJ, Sousa RA, Oliveira JT, Neves NM, Mano JF, et al. Starch/gellan gum hybrid 3D guidance systems for spinal cord injury regeneration: Scaffolds processing, characterization and biological evaluation. Tissue Eng Part A. 2008;14:779.Google Scholar
- 14.Silva NA, Sousa RA, Oliveira JT, Fraga JS, Fontes M, Cerqueira R, et al. Benefits of Spine Stabilization with Biodegradable Scaffolds in Spinal Cord Injured Rats. Tissue Engineering Part C. 2012. doi: 10.1089/ten.TEC.2012.0264.
- 27.Silva N, Salgado AJ, Sousa RA, Oliveira JO, Pedro AJ, Mastronardi F, et al. Development and characterization of a novel hybrid tissue engineering based scaffold for spinal cord injury repair. Tissue Eng. 2008;16:45–54.Google Scholar
- 40.Oliveira AL, Malafaya PB, Costa SA, Sousa RA, Reis RL. Micro-computed tomography (micro-CT) as a potential tool to assess the effect of dynamic coating routes on the formation of biomimetic apatite layers on 3D-plotted biodegradable polymeric scaffolds. J Mater Sci Mater Med. 2007;18:211–23.CrossRefGoogle Scholar
- 41.Hirota M, Hayakawa T, Ametani A, Kuboki Y, Sato M, Tohnai I. The effect of hydroxyapatite-coated titanium fiber web on human osteoblast functional activity. Int J Oral Maxillofac Implants. 2011;26:245–50.Google Scholar
- 49.Hayakawa T, Takahashi K, Yoshinari M, Okada H, Yamamoto H, Sato M, et al. Trabecular bone response to titanium implants with a thin carbonate-containing apatite coating applied using the molecular precursor method. Int J Oral Maxillofac Implants. 2006;21:851–8.Google Scholar