484 The Role of Plasma Derived Purified Exosome Product (PEP) for Improved Locomotor Recovery in Spinal Cord Injured Rats

Abstract

INTRODUCTION: Preclinical studies indicate that mesenchymal stem cell-derived secretomes exert immunomodulatory and neuroprotective effects in various spinal cord injury models. Exosomes as one of the secretomes, have been shown to successfully aid wound healing for the skin and following myocardial infarction. However, the effects of human plasma-derived purified exosomal products (PEP) on spinal cord injury (SCI) have not been explored to this date. METHODS: Twenty-four female rats were randomly divided into five groups. These included 2 control groups for the I.V or I.T injected PEP groups and a sham group. Groups were subject to a T9 laminectomy, followed by a moderate contusion SCI. After 24 hours, lactated ringer solution or PEP was injected through I.V or IT routes. Rats were assessed weekly for a total period of 10 weeks by an open field Basso, Beattie, and Bresnahan (BBB) motor score and a postmortem quantification of external scaring, neuronal regeneration, cavity volume, and glial scarring was carried out at the end of the follow-up period. RESULTS: Animals treated with I.V PEP or IT PEP had significant improvement within the first-week post-injury (1.05±1.2 vs. 2.16±3.15) and (1.08±3.5 vs. 4.5±0.083) respectively, with sustained improvement in BBB score at 10 weeks (11±1.16 vs. 13.8±1.90), (11.3±1.4 vs. 14±1.16). CONCLUSION: Our preliminary results suggest that I.V or IT PEP injection without immunosuppression might provide beneficial effects initially following traumatic SCI.