Genome engineering for CNS injury and disease

Modelling Neurological Diseases in Large Animals: Criteria for Model Selection and Clinical Assessment

Issue: The impact of neurological disorders is recognised globally, with one in six people affected in their lifetime and few treatments to slow or halt disease progression. This is due in part to the increasing ageing population, and is confounded by the high failure rate of translation from rodent-derived therapeutics to clinically effective human neurological interventions. Improved translation is demonstrated using higher order mammals with more complex/comparable neuroanatomy. These animals effectually span this translational disparity and increase confidence in factors including routes of administration/dosing and ability to scale, such that potential therapeutics will have successful outcomes when moving to patients. Coupled with advancements in genetic engineering to produce genetically tailored models, livestock are increasingly being used to bridge this translational gap. Approach: In order to aid in standardising characterisation of such models, we provide comprehensive neurological assessment protocols designed to inform on neuroanatomical dysfunction and/or lesion(s) for large animal species. We also describe the applicability of these exams in different large animals to help provide a better understanding of the practicalities of cross species neurological disease modelling. Recommendation: We would encourage the use of these assessments as a reference framework to help standardise neurological clinical scoring of large animal models.

RNA interference in glial cells for nerve injury treatment

Drivers of RNA interference are potent for manipulating gene and protein levels, which enable the restoration of dysregulated mRNA expression that is commonly associated with injuries and diseases. This review summarizes the potential of targeting neuroglial cells, using RNA interference, to treat nerve injuries sustained in the central nervous system. In addition, the various methods of delivering these RNA interference effectors will be discussed.

Challenges of gene delivery to the central nervous system and the growing use of biomaterial vectors

Gene therapy is a promising form of treatment for those suffering from neurological disorders or central nervous system (CNS) injury, however, obstacles remain that limit its translational potential. The CNS is protected by the blood brain barrier, and this barrier blocks genes from traversing into the CNS if administered outside of the CNS. Viral and non-viral gene delivery vehicles, commonly referred to as vectors, are modified to enhance delivery efficiency to target locations in the CNS. Still, there are few gene therapy approaches approved by the FDA for CNS disease or injury treatment. The lack of viable clinical approaches is due, in part, to the unpredictable nature of many vector systems. In particular, safety concerns exist with the use of viral vectors for CNS gene delivery. To seek some alternatives to viral vectors, development of new non-viral, biomaterial vectors is occurring at a rapid rate. This review discusses the challenges of delivering various forms of genetic material to the CNS, the use and limitations of current viral vector delivery systems, and the use of non-viral, biomaterial vectors for CNS applications.

Recent advances in nanotherapeutic strategies for spinal cord injury repair

Spinal cord injury (SCI) is a devastating and complicated condition with no cure available. The initial mechanical trauma is followed by a secondary injury characterized by inflammatory cell infiltration and inhibitory glial scar formation. Due to the limitations posed by the blood-spinal cord barrier, systemic delivery of therapeutics is challenging. Recent development of various nanoscale strategies provides exciting and promising new means of treating SCI by crossing the blood-spinal cord barrier and delivering therapeutics. As such, we discuss different nanomaterial fabrication methods and provide an overview of recent studies where nanomaterials were developed to modulate inflammatory signals, target inhibitory factors in the lesion, and promote axonal regeneration after SCI. We also review emerging areas of research such as optogenetics, immunotherapy and CRISPR-mediated genome editing where nanomaterials can provide synergistic effects in developing novel SCI therapy regimens, as well as current efforts and barriers to clinical translation of nanomaterials.