Intranasal and intracerebroventricular delivery of metabolically glycoengineered neural stem cells to enhance post–cardiac arrest brain recovery

Cardiac arrest leads to global cerebral ischemia, causing significant neurological deficits with few effective treatments currently available. Neural stem cell (NSC) transplantation has shown therapeutic promise; however, challenges remain to achieve optimal and consistent delivery while maximizing cell functionality post-transplantation. Metabolic glycoengineering (MGE) has emerged as a novel technique to improve NSC viability and therapeutic efficacy by modifying their glycans. This report compares the effects of different delivery routes for this innovative approach of using MGE-modified NSCs (MGE-NSCs) to treat ischemic brain injury post-cardiac arrest. A total of 16 rats were subjected to 9-minute asphyxia cardiac arrest (4 weeks) and 21 rats subjected to 11-minute asphyxia cardiac arrest (3 days) to model severe and very severe brain injury, respectively. The MGE-NSCs were administered either intranasally or intracerebroventricularly (ICV) 3 hours after resuscitation. Neurological deficits and neurobehavior tests were assessed periodically after resuscitation. Neuronal damage was examined with Fluro-Jade C staining and cresyl violet staining. The transplanted MGE-NSCs were tracked using immunofluorescence staining. In the early phase of recovery, the ICV administration resulted in better neurological deficit scores shortly after resuscitation compared with the intranasal route. Three days post-resuscitation, MGE-NSCs were primarily located in the cortex and hippocampus, with a higher percentage in the ICV-treated group. However, by 4 weeks, rats treated with intranasal MGE-NSCs exhibited superior locomotor function and reduced anxiety-/depression-related behaviors compared with those receiving ICV-NSC therapy. This was accompanied by greater survival and distribution of MGE-NSCs to the cerebellum and brainstem, along with reduced microglia recruitment. MGE-NSCs administered via both delivery methods enhanced vascular angiogenesis, neuron differentiation, and synaptic plasticity. Overall, intranasal delivery was as effective or potentially superior to ICV for long-term recovery, whereas ICV conferred short-term advantages. These results highlight the potential of MGE-NSC therapy to enhance post-cardiac arrest recovery, advocating for tailored treatment strategies based on specific recovery phase goals.