Neurorestorative effect of olfactory ensheathing cells and Schwann cells by intranasal delivery for patients with ischemic stroke: design of a multicenter randomized double-blinded placebo-controlled clinical study

There have been many clinical studies or trials for patients with ischemic stroke by cell therapy, which includes olfactory ensheathing cell (OEC), mononuclear cell, mesenchymal stromal cell, fetal neural cell or products of varying stem cells, etc. Those cells through different transplanting ways have showed moderate neurorestorative effect in patients with ischemic stroke, but majority were not multicenter randomized, double-blinded, placebo-controlled studies or trials. OEC transplantation has shown a more effective to restore neurological damage in central nervous system (CNS). We hypothesize that OEC through intra-olfactory mucosa transplantation can migrate into the ischemic stroke area around and restore neurological deficit caused from this disaster.

This is a multicenter, randomized, double-blinded, placebo- controlled 12 month clinical study of OECs and Schwann cells (SCs) for patients with sub-acute ischemic stroke and chronic ischemic stroke, to test which kind of cell has more neurorestorative effect for patients with ischemic stroke relative to placebo.

This study is involved two groups of patients with sub-acute ischemic stroke and chronic ischemic stroke. Each group enrolls 30 patients. The experimental intervention consists in using OECs and SCs through intra-olfactory mucosa transplantation in participating patients. This will be compared with using placebo (injecting cell culture medium). Participating patients in groups of sub-acute ischemic stroke and chronic ischemic stroke are randomized in natural order to divide into A, B, or C groups and get one of experimental treatment procedures. Patients, operating physicians, and assessing physicians are left unaware of what cells or medium will be injected to participating patients. All patients will be assessed before treatment and after one month, three months, six months, and one year.

The clinical study protocol and consent form were approved by Chinese Association of Neurorestoratology and the ethics committees of the hospitals which joined this clinical study. Findings will be published in peer-reviewed journals.