Fe3O4@polydopamine nanoparticle-loaded human umbilical cord mesenchymal stem cells improve the cognitive function in Alzheimer's disease mice by promoting hippocampal neurogenesis

One of the most promising treatments for neurodegenerative diseases is the stem cell therapy; however, there are still some limitations in the treatment of Alzheimer's disease. In this study, superparamagnetic nanoparticles composed of magnetic Fe 3 O 4 and polydopamine shells were used to label human umbilical cord mesenchymal stem cells (hUC-MSCs) in order to increase the targeting of hUC-MSCs. Our data suggested that Fe 3 O 4 @PDA labeling increase the efficiency of hUC-MSCs entering the brain. Moreover, the water maze test showed that compared with hUC-MSCs only, Fe 3 O 4 @PDA-labeled hUC-MSCs improved the cognitive ability of APP/PS1 transgenic mice more significantly. Other experimental data showed that the expression of essential proteins in the hippocampus, such as Aβ, synaptophysin, brain-derived neurotrophic factor, are affected by Fe 3 O 4 @PDA coated-hUC-MSCs. The regulation of Fe 3 O 4 @PDA coated-hUC-MSCs could improve the memory and cognitive ability of AD mice by excessive generation of neuroprotective factors, which might be considered a viable therapy to treat AD. Stem cell therapy is a promising method for AD, our data also showed that Fe 3 O 4 @PDA is a promising magnetic nanomaterial, which did not affect the biological characteristics of hUC-MSCs, and increased the targeting of hUC-MSCs in mice. Fe 3 O 4 @PDA-labeled hUC-MSCs improved the cognitive ability of APP/PS1 transgenic mice. It provides a new idea for AD and broadens the treatment approach.