Witters, M. | Search bioRxiv

bioRxiv2025

Human nasal olfactory stem cell-derived extracellular vesicles improve the repair of rat nerves

Damage to the peripheral nerve impairs quality of life. Despite the advances in surgery to facilitate nerve regeneration, complete recovery remains elusive. Human olfactory ecto-mesenchymal stem cells (OEMSC) have potential for the treatment of peripheral nerve injury through the release of extracellular vesicles (EV). The current research investigates the therapeutic effects of a venous bridge, filled with freshly purified or cryoconserved OEMSC-derived EVs after a peroneal nerve loss of substance. Injured peroneal nerve was bridged with a vein into which freshly purified or cryoconserved EVs were injected or not. Nerve repair was analyzed by measuring locomotor function, muscle mechanical properties, muscle mass, axon number, and myelination. The EVs significantly increased locomotor recovery, maintained the contractile phenotype of the target muscle, and augmented the number of growing axons. These results demonstrate that EVs display a positive effect on peripheral nerve regeneration, representing an alternative to cellular therapies for peripheral nerve repair.

neuroscience↗

bioRxiv2022

Culture of human nasal olfactory stem cells and their extracellular vesicles as advanced therapy medicinal products

The olfactory ecto-mesenchymal stem cell (OE-MSC) are mesenchymal stem cells originating from the lamina propria of the nasal mucosa. They have neurogenic and immune-modulatory properties and showed therapeutic potential in animal models of spinal cord trauma, hearing loss, Parkinsonss disease, amnesia, and peripheral nerve injury. In this paper we designed a protocol that meet the requirements set by human health agencies to manufacture these stem cells for clinical applications. Once purified, OE-MSCs can be used per se or expanded in order to get the extracellular vesicles (EV) they secrete. A protocol for the extraction of these vesicles was validated and the EV from the OE-MSC were functionally tested on an in vitro model. Nasal mucosa biopsies from three donors were used to validate the manufacturing process of clinical grade OE-MSC. All stages were performed by expert staff of the cell therapy laboratory according to aseptic handling manipulations, requiring grade A laminar airflow. Enzymatic digestion provides more rapidly a high number of cells and is less likely to be contaminated. Foetal calf serum was replaced with human platelet lysate and allowed stronger cell proliferation, with the optimal percentage of platelet lysate being 10%. Cultivated OE-MSCs are sterile, highly proliferative (percentage of CFU-F progenitors was 15,5%) and their maintenance does not induce chromosomal rearrangement (karyotyping and chromosomal microarray analysis were normal). These cells express the usual phenotypic markers of OE-MSC. Purification of the EVs was performed with ultracentrifugation and size exclusion chromatography. Purified vesicles expressed the recognized markers of EVs (Minimal Information for Studies of Extracellular Vesicles ("MISEV") guidelines) and promoted cell differentiation and neurite elongation in a model of neuroblastoma Neuro2a cell line. We developed a safer and more efficient manufacturing process for clinical-grade olfactory stem cells, these cells can now be used in humans. A phase I clinical trial will begin soon.An efficient protocol for the purification of the OE-MSC EVs have been validated. These EVs exert neurogenic properties in vitro. More studies are needed to understand the exact mechanisms of action of these EVs and prove their efficacy and safety in animal models.

neuroscience↗