Safety of intraparenchymal injection of allogenic placenta mesenchymal stem cells derived exosome in patients undergoing decompressive craniectomy following malignant middle cerebral artery infarct, a pilot randomized clinical trial

Malignant middle cerebral artery infarct (mMCAI) largely contributes to high mortality and physical disability among adults. Surviving individuals may not have proper outcomes and suffer from severe lasting disabilities. Utilization of stem cells and paracrine factor for regenerative purposes is considered as a potential strategy for patients with neurological deficits. While preclinical stroke studies have shown that mesenchymal stem cells (MSCs) reduce post‑treatment neurological deficits and prevent disability and also promote recovery, few randomized clinical trials (RCT) have assessed exosome therapy in humans.

In this RCT, we assessed the safety of intraparenchymal injection placenta MSC‑derived Exosome in mMCAI patients with average age of 62 years between January, 2019, till September, 2020. The study was done in a single‑center as an open‑label RCT, with a 3‑months follow‑up. Primary outcomes assessed the safety and also disability indexes were followed.

Five mMCAI patients were included with mean NIHSS: 17.6 ± 5.02. The mean MRS was 3.25 ± 0.95 in three patients. No serious adverse events were observed. Hematoma or local reaction as excessive edema were not seen at the site of injection.

Intraparenchymal implantation of MSC‑EXO showed no post‑interventional adverse effects in five ischemic stroke patients. It is proposed Local injection Exosome treatment following mMCAI can be safe and in future, it would be applied as a supportive, restorative and preventive treatment in patients who suffer from acute ischemic stroke and post ischemic disability.