The differentiation of neural stem cells via nanomaterials has attracted attention and has become a potential tool. However, the chirality effect in neural stem cell differentiation has not been investigated. Here, this study shows that chiral nanoparticles (NPs) with strong chirality can efficiently accelerate the differentiation of mouse neural stem cells (NSCs) into neurons under near‐infrared (NIR) light illumination. L‐type NPs are 1.95 times greater than D‐type NPs in promoting NSCs differentiation due to their 1.47‐fold endocytosis efficiency. Whole gene expression map analysis reveals that circularly polarized light illumination and chiral NPs irradiation significantly upregulate Map2, Yap1, and Taz genes, resulting in mechanical force, cytoskeleton protein action, and accelerated NSCs differentiation. In vivo experiments show that successful differentiation can further alleviate symptoms in Alzheimer's disease mice. Moreover, the clearance of L‐type NPs on amyloid and hyperphosphorylated p‐tau protein reachs 68.24% and 66.43%, respectively, under the synergy of NIR irradiation. The findings suggest that strong chiral nanomaterials may have advantages in guiding cell development and can be used in biomedicine.

Chiral nanostructures have been extensively studied for bioanalysis and optoelectronics because of their high rotatory optical activity but not for enantioselective catalysis because of the chirality mismatch of geometric scales. Here, we investigate whether the catalytic activity of supraparticles (SPs) made from ZnS NPs could provide a general pathway to reconcile the difficulties. SPs synthesized by two different pathways could enantioselectively oxidize tyrosine (Tyr). Upon illumination with 300–450 nm photons, SPs could convert Tyr into the catechol derivative dihydroxyphenylalanine (DOPA) and Tyr–Tyr dimers coupled via a C–C bond. The enantiomeric preference of substrate conversion is 23–26%, which is an order of magnitude greater than that with metalorganic compounds for the comparable catalytic process in organic solvents. Chiral catalysis substantiated by a photocatalytic oxidation of tryptophan (Trp) could predominantly lead to catechol derivatives with similar enantiomeric preference of 21–25%. This study opens the door to enantioselective catalysts for aqueous mediums taking advantage of the catalytic, photonic, and self-assembly properties of chiral NPs.

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 Mn 3 O 4 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, Mn 3 O 4 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 Mn 3 O 4 NPs into MN9D cells is mediated by caveolin. The data demonstrate that Mn 3 O 4 nanorods can be taken up by cells effectively and confer excellent levels of neuroprotection while the biodegradation of Mn 3 O 4 NPs in vivo is confirmed by photoacoustic image of Mn 3 O 4 NPs in brain at 60 d. Furthermore, the oxygen scavenging effect created by Mn 3 O 4 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 Mn 3 O 4 NPs for the clinical therapy of neurodegenerative disease.