Encapsulating methylene blue within the magnetic‐derived nanoparticle facilitated its permeations across the BBB and enhanced its bioaccumulation in target tissue. Furthermore, the synthesized NPs were able to effectively target hyperphosphorylated tau, facilitate neuronal stability, decrease inflammation and damage to hippocampal regions. In vivo studies with AD rats that the conjugated NPs improved memory and cognition. This evidence concerns the gene MAPT and Alzheimer disease.