Intralesional mesenchymal stromal cell transplant in a rodent model of cortical cryoinjury

Background: The effect of intralesional mesenchymal stromal cell (MSC) transplant in the subacute phase of brain injury has not been studied.
Aim: To evaluate the role of intralesional transplant of mouse MSC following coldinduced cerebral cortical injury in mouse in improving neurological function.
Material and Methods: Twelve mice (Swiss albino strain) received an intralesional injection of 2×10⁶ mouse MSCs labelled with Bromodeoxyuridine (BrdU) and suspended in phosphate-buffered saline (PBS), 72 h after cerebral cryoinjury. Six mice received intralesional injection of PBS and served as controls. Neurological severity score (NSS) and rotarod treadmill test were used to perform serial assessments.
Results: The mean NSS in the control group (n=5) on the first posttrauma day was 9.3±1.2 and it improved to 14.2±1.3 on day 28. The mean NSS in the MSC group (n=11) was 10.7±1.8 on the first posttrauma day and it improved to 16±1.1 on day 28 posttransplant. This difference was not found to be statistically significant when subgroup analysis of animals, where the assessments were blinded, was performed. There was no significant difference in the rotarod treadmill scores between the control and the MSC group at any time point. Few BrdU-positive cells could be identified in the periphery of the contusion up to day 10 posttransplant.
Conclusions: Transplanted MSCs were shown to survive for at least 10 days after intralesional transplant in the cryoinjury model of the mouse cerebral cortex but the functional recovery observed in the experimental group was not statistically different from the controls.