Initiating and Facilitating Brain Repair: Factors, Principles, and Mechanisms

Introduction: Acute injuries to the brain result in a wide range of sequelae, and several factors contribute to the severity of a brain lesion, including age, overall health, and extension and site of the injury. Complete brain repairBrain repair after a massive traumatic brain injuryTraumatic Brain Injury (TBI) or strokeStroke remains challenging. During the acute phase of the injury, the inflammatory microenvironmentMicroenvironment can induce further neuronal death. The lack of structural support for cellular repopulation, anchoring, and synapse formation reduces the repair chances. After the acute phase, the glial scar formed by reactive astrocytes and oligodendrocytes dramatically decreases the possibility for the surviving neurons to restore damaged synapses. Methods: We reviewed studies describing the development of bioengineering techniques, with the production of biocompatible new biomaterialsBiomaterials that can become the next step in neurorepair. Results: Various natural and synthetic materials have been used to replace damaged tissue, and using induced pluripotent stem cellsStem cell to originate neurons from the patient dramatically reduces the chances of rejection of biomaterialBiomaterials populated with cells, creating innovative biopatches. Besides using biomaterialBiomaterials constructs to deliver cells, bioscaffoldsBioscaffolds can deliver genes, nanoparticles, soluble factors, and exosomes to induce neurorepair in a more controllable and permanent manner. Conclusions: Understanding the cellular and molecular mechanisms activated in response to brain injury is critical to designing and developing successful brain repairBrain repair strategies.