The Study On A Rodent Model With The Implantation Of A Poly (2-hydroxyethyl Methacrylate) Scaffold In The Injured Spinal Cord

Spinal cord injury (SCI) caused directly or indirectly by accidents or trauma canlead to loss of function, touch and dysfunction of muscle. Damage to the spinal cordstarts from the initial trauma, followed by a detrimental delayed secondary pathologythat occurs in the hours and days. In face of the complex nature of spinal cord injury,researchers have used tissue engineering scaffolds as regenerative matrices for thedamaged nerve. Owing to their good flexibility, permeability and aquosity,poly(2-hydroxyethyl methacrylate)(pHEMA) scaffolds have already been examined aspossible matrices for nerve regeneration in spinal cord injury. However, being the criticalstage for recovery, the early sequence of inflammation events after pHEMA scaffoldsimplantation has not yet been revealed. Hence, in this dissertation, based on the rat spinalcord injury model, we investigated the cellular and molecular microenvironment of theinjured spinal cord with or without pHEMA scaffolds. This allows the understanding ofearly inflammatory response to regeneration in pHEMA Scaffolds implanted within theinjured rodent spinal cord. Methods: Based on the rat spinal cord injury model, pHEMA scaffolds wereimplanted into partially transected white matter and the research focused on thecomparatively short time points to investigate the innate immune response after pHEMAscaffolds implantation. The animals were perfused after6and28days post-surgery, andthe cellular and molecular environment for both inflammatory and regenerative processesare examined by immunohistochemical staining and real-time PCR.Results: The animals reacted normally after surgery. At6and28days post-surgery,it has been observed that in both the lesion control and pHEMA group macrophages wereactivated and recruited to the site of injury. The endogenous glial cells, astrocytes,underwent dramatic changes in cell morphology and behavior. However, after28days,the glial scar thickening was suppressed by pHEMA scaffold intervention andneurofilaments regenerated a lot. A different inflammatory reaction was implied by theup-regulation of TGF-β1and FGF-1expression with pHEMA implants.Conclusion: The implantation of pHEMA scaffold just aroused mild inflammatoryresponse and significantly improved neurofilaments regrowth. Limitation put on theearly inflammatory response and scar tissue thickening by scaffold implantation issuggestive of a desirable and beneficial neuroprotective effect.