Regenerative biomaterial matrices for traumatic spinal cord repair

Abstract

International audienceThe ongoing search for novel, efficient therapeutic strategies for treatment of spinal cord injury (SCI) should greatly profit from the recent progress in the production of innovative biomaterials that when implanted into the lesion site, will function both as extracellular matrix substitute, and as bioactive support structure.Accordingly and as first step, we developed a therapeutic strategy based on the use of chitosan polymer, that exhibits ideal characteristics for tissue engineering. Biological evaluation of diverse formulations (varying in physical and chemicals features) allowed determining the formulations best suited to integrate into spinal cord tissue. Our experimental paradigm is a thoracic dorsal hemisection in adult female rat, with or without implantation of polymer directly after the lesion. Indeed, implantation of the selected chitosan hydrogel formulation induces (i) strong reduction of the astrocytic reaction, (ii) functional vascularization within the implant, (iii) modulated inflammatory response (iv), and most remarkably, growth of a very high number of axons through the implant, evidence for the material per se being extremely favorable for axon regrowth. Finally, these structural remodeling is associated with an improvement of the partial locomotor recovery. Because it effectively induces neural tissue repair, the chitosan biomaterial may be a promising new approach to treat SCI