Intraarterial route increases the risk of cerebral lesions after mesenchymal cell administration in animal model of ischemia

Mesenchymal stem cells (MSCs) are a promising clinical therapy for ischemic stroke. However, critical parameters, such as the most effective administration route, remain unclear. Intravenous (i.v.) and intraarterial (i.a.) delivery routes have yielded varied outcomes across studies, potentially due to the unknown MSCs distribution. We investigated whether MSCs reached the brain following i.a. or i.v. administration after transient cerebral ischemia in rats, and evaluated the therapeutic effects of both routes. MSCs were labeled with dextran-coated superparamagnetic nanoparticles for magnetic resonance imaging (MRI) cell tracking, transmission electron microscopy and immunohistological analysis. MSCs were found in the brain following i.a. but not i.v. administration. However, the i.a. route increased the risk of cerebral lesions and did not improve functional recovery. The i.v. delivery is safe but MCS do not reach the brain tissue, implying that treatment benefits observed for this route are not attributable to brain MCS engrafting after stroke.This study has been partially supported by grants from Axencia Galega de Innovación (Xunta de Galicia), the Instituto de Salud Carlos III (PI13/00292; PI14/01879), the Spanish Research Network on Cerebrovascular Diseases RETICS-INVICTUS (RD12/0014), Xunta de Galicia (Consellería Educación GRC2014/027), the European Commission program FEDER and Promoting Active Ageing program: Functional Nanostructures For Alzheimer’s Disease At Ultra-Early Stages” (Pana_686009), a Research and Innovation Project, funded within the EU Horizon 2020 Programme”. Furthermore, this study was also co-funded within the POCTEP (Operational Programme for Cross-border Cooperation Spain-Portugal) program (0681_INVENNTA_1_E), co-financed by the ERDF (European Regional Development Fund). T. Sobrino (CP12/03121) and F. Campos (CP14/00154) are recipients of a research contract from Miguel Servet Program of Instituto de Salud Carlos III. Finally, P. Taboada thanks Mineco and Xunta de Galicia for funding through projects MAT2013-40971-R and EM2013-046, respectively. J Trekker is the recipient of an innovation grant from the IWT-VlaanderenS