Magnetotactic Bacteria‐Derived Mms6 Gene Helps M2 Macrophages to Form Magnetic Bio‐Nanoparticles to Prevent Ferroptosis and Promote Locomotor Functional Recovery after Spinal Cord Injury in Mice

Abstract

Magnetotactic bacteria are microaerobic microorganisms that take up iron from solution and crystallize magnetite nanoparticles called magnetosomes, enclosed by membrane intracellularly and mainly formed by the magnetosome membrane‐specific 6 (Mms6) gene. M2 macrophages are transfected by magnetotactic bacteria‐derived Mms6 gene to form magnetic bio‐nanoparticles. Under myelin debris‐rich hypoxic stress in the spinal cord injury (SCI) microenvironment, Mms6‐transfected M2 macrophages can antagonize ferroptosis. Meanwhile, transplantation of Mms6‐transfected M2 macrophages into SCI mice through intracerebroventricular or intravenous injection can effectively promote structural repair and locomotor functional recovery. As a proof of concept, this study provides a novel strategy in immune cell therapy, which supports the survival and strengthens the function of M2 macrophages based on magnetic bio‐nanoparticles which help M2 macrophages to resist ferroptosis. This study also sheds light on this cross‐species applications for treating traumatic injury and inflammatory diseases.

Magnetic Nanoparticles and Methylprednisolone Based Physico‐Chemical Bifunctional Neural Stem Cells Delivery System for Spinal Cord Injury Repair

“…[ 33 ] It is widely believed that attenuating the inflammatory response and promoting macrophage M2 polarization during the acute phase of SCI is beneficial for SCI repair and the proliferation and survival of NSCs. [ 34 ] MP, an anti‐inflammatory drug recommended for SCI, is controversial due to the high‐dose and long‐term systemic administration which can lead to serious complications. [ 11 ] In recent years, many biomaterials have been used as carriers for the delivery of MP, achieving good therapeutic effects.…”