[Translated article] Effects of duroplasty with bovine pericardium on fibrosis and extent of spinal cord injury: An experimental study in pigs.

INTRODUCTION: Traumatic spinal cord injury (SCI) leads to increased intraspinal pressure that can be prevented by durotomy and duroplasty. The aim of the study was to evaluate fibrosis and neural damage in a porcine model of SCI after duroplasty and application of hyaluronic acid (HA) in the tissue cavity. MATERIALS AND METHODS: Experimental study. We created a porcine SCI model by durotomy and spinal cord hemisection of a cervical segment (1cm). Six pigs (Sus scrofa domestica) were used to evaluate three surgical scenarios: (1) control injury with dural reparative microsurgery, (2) duroplasty using bovine pericardium (BPD), and (3) previous method plus HA applied at the lesion. Animals were sacrificed one-month post-injury to assess fibrotic responses and neural tissue damage using conventional histological and immunohistochemical methods. RESULTS: In the control case, dural suture prevented invasion of the lesion by extradural connective tissue, and the dura mater showed a 1-mm thickening in the perilesional area. The bovine pericardium patch blocked the entrance of extradural connective tissue, decreased dura-mater tension, and satisfactorily integrated within the receptor tissue. However, it also enhanced subdural and perilesional fibrosis, which was not inhibited by filling the lesion cavity with low- or high-molecular-weight HA. CONCLUSIONS: Duroplasty prevents collapse of the dura-mater over the spinal cord tissue, as well as invasion of the lesion by extramedullary fibrotic tissue, without creating additional neural damage. Nevertheless, it enhances the fibrotic response in the spinal cord lesion and the perilesional area. Additional antifibrotic strategies are needed to facilitate spinal cord repair.

Effects of duroplasty with bovine pericardium on fibrosis and extent of spinal cord injury: An experimental study in pigs. / Efecto de la reparación de la duramadre con pericardio bovino sobre la fibrosis y la extensión de la lesión medular: estudio experimental en cerdos.

INTRODUCTION: Traumatic spinal cord injury (SCI) leads to increased intraspinal pressure that can be prevented by durotomy and duroplasty. The aim of the study was to evaluate fibrosis and neural damage in a porcine model of SCI after duroplasty and application of hyaluronic acid (HA) in the tissue cavity. MATERIALS AND METHODS: Experimental study. We created a porcine SCI model by durotomy and spinal cord hemisection of a cervical segment (1cm). Six pigs (Sus scrofa domestica) were used to evaluate three surgical scenarios: (1)control injury with dural reparative microsurgery, (2)duroplasty using bovine pericardium (BPD), and (3)previous method plus HA applied at the lesion. Animals were sacrificed one-month post-injury to assess fibrotic responses and neural tissue damage using conventional histological and immunohistochemical methods. RESULTS: In the control case, dural suture prevented invasion of the lesion by extradural connective tissue, and the dura mater showed a 1-mm thickening in the perilesional area. The bovine pericardium patch blocked the entrance of extradural connective tissue, decreased dura-mater tension, and satisfactorily integrated within the receptor tissue. However, it also enhanced subdural and perilesional fibrosis, which was not inhibited by filling the lesion cavity with low- or high-molecular-weight HA. CONCLUSIONS: Duroplasty prevents collapse of the dura-mater over the spinal cord tissue, as well as invasion of the lesion by extramedullary fibrotic tissue, without creating additional neural damage. Nevertheless, it enhances the fibrotic response in the spinal cord lesion and the perilesional area. Additional antifibrotic strategies are needed to facilitate spinal cord repair.

3D free-standing porous scaffolds made of graphene oxide as substrates for neural cell growth.

The absence of efficient therapies for the treatment of lesions affecting the central nervous system encourages scientists to explore new materials in an attempt to enhance neural tissue regeneration while preventing inhibitory fibroglial scars. In recent years, the superlative properties of graphene-based materials have provided a strong incentive for their application in biomedicine. Nonetheless, a few attempts to date have envisioned the use of graphene for the fabrication of three-dimensional (3D) substrates for neural repair, but none of these involve graphene oxide (GOx) despite some attractive features such as higher hydrophilicity and versatility of functionalization. In this paper, we report novel, free-standing, porous and flexible 3D GOx-based scaffolds, produced by the biocompatible freeze-casting procedure named ISISA, with potential utility in neural tissue regeneration. The resulting materials were thoroughly characterized by Fourier-transform infrared, Raman, and X-ray photoelectron spectroscopies and scanning electron microscopy, as well as flexibility testing. Embryonic neural progenitor cells were then used to investigate adhesion, morphology, viability, and neuronal/glial differentiation. Highly viable and interconnected neural networks were formed on these 3D scaffolds, containing both neurons and glial cells and rich in dendrites, axons and synaptic connections, and the results are in agreement with those obtained in initial studies performed with two-dimensional GOx films. These results encourage further investigation in vivo on the use of these scaffolds as guide substrates to promote the repair of neural injuries.

[Traumatic injuries to the central nervous system and their repair]. / Trauma en el sistema nervioso central y su reparación.

DEVELOPMENT: Brain and spinal cord lesions have an increasing social and economic importance. Accidental trauma of various kinds is the main cause of mortality of children and young adults in developed countries. Only cardiac disease and cancer surpass the number of death caused by accidents and, examining the number of potential work years lost, CNS lesions surpass all other problems. Most brain and spinal cord injuries cause chronic incapacity and frequently occur to individuals under 45 years of age. Edema and other acute events can be efficiently treated and CNS lesions may not be mortal, but are incurable. CONCLUSION: The final outcome of CNS injury depend on the area damaged and the extent of the lesion, but the best present therapies can offer is relief of the symptoms and rehabilitation. This review examines the present state of functional repair of experimental central nervous system trauma.

Developmental and reactive growth of dentate gyrus afferents: cellular and molecular interactions.

The lamination of dentate gyrus afferents established during development is maintained following lesion-induced reactive growth in the adult. After partial deafferentation sprouts from undamaged afferents restore most synapses, while respecting the laminae relative boundaries. No evidence of trans-laminar sprouting has been found. Here, we review the information gathered during the last decade on the cellular and molecular bases of dentate synaptogenesis, with special attention to the role of glia during development and that of reactive glia after deafferentation. The interactions of neurons with astroglia and astroglial macromolecules, particularly proteoglycans, influence synapse segregation in the dentate gyrus, providing us with a reasonable explanation for afferent lamination.