Facet-Dependent Biodegradable Mn₃ O₄ Nanoparticles for Ameliorating Parkinson's Disease

Parkinson's disease (PD) is a common neurodegeneration disease. Unfortunately, there are no effective measures to prevent or inhibit this disease. In this study, biodegradable Mn₃ O₄ nanoparticles (NPs) in different shapes are prepared and enclosed them by {100}, {200} and {103} facets that exhibit facet-dependent protection against neurotoxicity induced by oxidative damage in a cell model of PD. Notably, Mn₃ O₄ nanorods enclosed by {103} facets exhibit high levels of enzyme-like activity to eliminate reactive oxygen specie in vitro. It is also determined that the uptake pathway of Mn₃ O₄ NPs into MN9D cells is mediated by caveolin. The data demonstrate that Mn₃ O₄ nanorods can be taken up by cells effectively and confer excellent levels of neuroprotection while the biodegradation of Mn₃ O₄ NPs in vivo is confirmed by photoacoustic image of Mn₃ O₄ NPs in brain at 60 d. Furthermore, the oxygen scavenging effect created by Mn₃ O₄ nanorods is successfully applied to a mouse model of PD; the amount of α-synuclein in the cerebrospinal fluid of PD mice is reduced by 61.2% in two weeks, thus demonstrating the potential application of facet-directed Mn₃ O₄ NPs for the clinical therapy of neurodegenerative disease.