Ferrimagnetic Nanochains‐Based Mesenchymal Stem Cell Engineering for Highly Efficient Post‐Stroke Recovery

Abstract Unsatisfactory post‐stroke recovery has long been a negative factor in the prognosis of ischemic stroke due to the lack of pharmacological treatments. Mesenchymal stem cells (MSCs)‐based therapy has recently emerged as a promising strategy redefining stroke treatment; however, its effectiveness has been largely restricted by insufficient therapeutic gene expression and inadequate cell numbers in the ischemic cerebrum. Herein, a non‐viral and magnetic field‐independent gene transfection approach is reported, using magnetosome‐like ferrimagnetic iron oxide nanochains (MFIONs), to genetically engineer MSCs for highly efficient post‐stroke recovery. The 1D MFIONs show efficient cellular uptake by MSCs, which results in highly efficient genetic engineering of MSCs to overexpress brain‐derived neurotrophic factor for treating ischemic cerebrum. Moreover, the internalized MFIONs promote the homing of MSCs to the ischemic cerebrum by upregulating CXCR4. Consequently, a pronounced recovery from ischemic stroke is achieved using MFION‐engineered MSCs in a mouse model.