Researchers from the Institute of Process Engineering (IPE) of the Chinese Academy of Sciences, in collaboration with Shenzhen Second People's Hospital, have developed a breakthrough exosome-based therapeutic agent for treating traumatic central nervous system (CNS) injuries. The novel treatment, published in Cell Reports Medicine, represents a significant advancement in addressing the limited therapeutic options currently available for traumatic brain injury (TBI) and traumatic spinal cord injury (SCI).
Addressing Critical Treatment Gaps
Traumatic CNS injuries are characterized by oxidative damage and neuroinflammation, with current treatment approaches primarily limited to supportive care and surgical intervention. The lack of effective drugs to directly target underlying damage has created a significant unmet medical need. While neural stem cell (NSC)-based therapy has shown therapeutic potential, pathological microenvironments negatively impact NSC survival and directed differentiation, compromising therapeutic outcomes. Similarly, antioxidant treatments have achieved limited success because most antioxidants cannot efficiently cross the blood-brain barrier (BBB).
Innovative Selenium-Enhanced Exosome Design
Understanding that NSC therapy involves cell-to-cell communication via exosomes—nanosized vesicles secreted by cells, including NSCs—the researchers proposed using NSC-derived exosomes (NExo) to treat CNS injury. The exosomes demonstrate stability and maintain medical activity in pathological microenvironments, offering advantages over direct cell therapy approaches.
Recognizing that exosome-based therapy needed to address oxidative damage caused by reactive oxygen species (ROS) in the microenvironment, the research team developed an advanced NExo containing ultrasmall nano-selenium particles (~3.5 nm) via lipid-mediated nucleation, creating SeNExo.
Mechanism of Action and BBB Penetration
Professor MA Guanghui from IPE explained that SeNExo penetrates the BBB via the APOE-LRP-1 interaction after intravenous injection. Upon efficiently reaching the lesion site, the ultrasmall nano-selenium effectively scavenges ROS, while NExo promotes neuronal repair through dual therapeutic mechanisms.
Comprehensive Preclinical Validation
Traumatic Brain Injury Results
In mouse TBI models, SeNExo demonstrated significant therapeutic benefits by reducing cerebral lesions and improving spatial learning and memory functions. Through comprehensive analysis using proteomics, miRNA omics, and single-nucleus RNA sequencing, researchers demonstrated that SeNExo significantly downregulated the expression of genes related to oxidative stress and apoptosis in neurons.
The treatment profoundly altered the transcriptional program of inflammatory responses, promoting glial cells toward homeostasis. Additionally, SeNExo enhanced neuron-glia ligand-receptor pairs involved in CNS development while suppressing those associated with inflammation and astrogliosis.
Spinal Cord Injury Outcomes
In mouse SCI models, SeNExo also promoted locomotor recovery, demonstrating the therapy's broad applicability across different types of traumatic CNS injuries.
Clinical Translation Potential
Professor TAN Hui from Shenzhen Children's Hospital and LI Weiping from Shenzhen Second People's Hospital support the concept that SeNExo represents a novel and promising therapeutic agent for treating traumatic CNS injury. A peer reviewer from Cell Reports Medicine noted that the study provides convincing evidence that SeNExo can protect the brain following TBI and potentially SCI.
Therapeutic Advantages
The SeNExo approach offers several key advantages over existing treatment modalities:
- Dual mechanism of action: Combines ROS scavenging with neuronal repair promotion
- BBB penetration: Efficiently crosses the blood-brain barrier through established biological pathways
- Stability: Maintains therapeutic activity in pathological microenvironments
- Broad applicability: Demonstrates efficacy in both TBI and SCI models
- Molecular precision: Targets specific pathways involved in oxidative stress and neuroinflammation
The development of SeNExo represents a significant step forward in addressing the complex pathophysiology of traumatic CNS injuries, offering hope for improved therapeutic outcomes in conditions that currently have limited treatment options.
