BDNF-EXO

**BDNF-EXO** refers to **exosomes loaded with brain-derived neurotrophic factor (BDNF)**, typically derived from human umbilical cord mesenchymal stem cells or neural stem cells, and engineered to deliver BDNF directly to target tissues. BDNF is a neurotrophic protein crucial for the survival and function of neurons, binding primarily to the TrkB receptor (tropomyosin receptor kinase B), activating signaling pathways involved in neuronal survival, differentiation, and plasticity in neurodegenerative and neuropsychiatric disorders. BDNF-EXO leverages exosomes as a delivery vehicle to cross the blood-brain barrier, enabling efficient CNS delivery. Preclinical studies in Parkinson's disease models show that BDNF-EXO suppresses apoptosis and ferroptosis, stabilizes neuronal cytoskeleton, promotes antioxidant defense via Nrf2 signaling, and generally improves neurological outcomes. Similar approaches, with BDNF-engineered exosomes, have been employed in models of major depressive disorder and ischemic stroke, showing neuroprotective and anti-inflammatory actions. BDNF-EXO is an emerging therapy for CNS diseases resistant to conventional drug delivery due to the blood-brain barrier.