Neural exosome therapeutics for treating opioid-induced brain hypoxia injuries - 7. Project Summary/Abstract Non-fatal opioid-associated overdose (NFOO)-induced brain hypoxia and injuries have limited treatment options. While the current therapeutics, such as naloxone, for fentanyl overdoses has substantially reduced fatalities, the resulting brain injuries from NFOO remain a significant challenge. NFOO-induced brain hypoxia will often result in neuroinflammation and neurodegeneration, and therapeutics that suppress these effects will provide a new opportunity to treat NFOO- induced brain injury. Exosomes are a new therapeutic strategy that has recently emerged as a treatment for inflammatory diseases. Exosomes are a class of small extracellular vesicles capable of delivering various cargo (eg. proteins/peptides, siRNA, and small molecules) to cells for treatment. Several clinical trials are underway to evaluate the safety and efficacy of exosome therapeutics. The major benefits of exosome therapy are their low immunogenicity, anti-inflammatory activity, ability to cross the BBB and targeting capabilities. Aruna Bio has established itself as a leader in the exosome space, due to its patented, neural exosome platform technology. Aruna’s neural exosomes, termed AB126, are generated from human pluripotent stem cell-derived neural progenitors and have an enhanced ability to penetrate the BBB to target neural cell types. AB126, as a standalone therapeutic, has demonstrated efficacy for the treatment of stroke, through its neuroprotective and anti-inflammatory effects, and is anticipated to be in clinical trials during 2025. Preliminary data in this application demonstrates AB126 anti- inflammatory effects, along with our novel peptide-exosome coupling technology that enables endosome escape and can be extended for therapeutic peptide delivery. AB126-coupled peptides potentially represent a new class of therapeutics that could have a major impact for treating hypoxic brain injuries. The long-term goal of Aruna Bio is to develop novel exosome-based therapeutics for the treatment of hypoxia- associated CNS diseases. In this phase 1 proposal, AB126 will be evaluated for its ability to suppress brain hypoxia induced neuroinflammation following fentanyl treatment in rats (Aim 1), and the ability of AB126-coupled peptides, which inhibit hypoxia signaling, to suppress fentanyl effects in vitro and in vivo (Aim 2). At the completion of this study, proof-of-concept studies for the AB126 therapeutics for treating fentanyl-induced brain injuries will have been demonstrated, which will facilitate the additional development of AB126 therapeutics under chronic fentanyl use in phase 2, leading to future phase 1/2 clinical trials. This application is a submission to RFA-DA-25- 050, “Solutions to enable diagnosis and treatment of adverse health consequences of non-disordered drug use”. This proposal directly addresses the critical need of developing new therapeutics for treating NFOO-induced brain hypoxia.