Chiral Se@CeO2 superparticles for ameliorating Parkinson's disease.

In this study, we prepare chiral D-/L-type Se@CeO2 superparticles (D-/L-SPs) with a g-factor of 0.018 using D-/L-cysteine as chiral ligands. The chiral SPs demonstrate ultra-high enzyme activity of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Due to the synergistic effect between Se and CeO2, the maximum initial velocity of GPx, CAT, and POD for L-SP is 10, 7, and 5.6 times higher than that of a mixture of Se nanoparticles (NPs) and CeO2 NPs. Significantly, the chiral L-SPs show much stronger ROS scavenging ability than D-SP in the PD-like cell model. Moreover, the amount of α-synuclein (α-syn) in the cerebrospinal fluid of PD mice is reduced by 70.7% within two weeks. The L-SPs effectively alleviate neurodegeneration in a mouse model of PD, showing potential applications in the clinical treatment of neurodegenerative diseases.

Circularly Polarized Light-Enabled Chiral Nanomaterials: From Fabrication to Application.

For decades, chiral nanomaterials have been extensively studied because of their extraordinary properties. Chiral nanostructures have attracted a lot of interest because of their potential applications including biosensing, asymmetric catalysis, optical devices, and negative index materials. Circularly polarized light (CPL) is the most attractive source for chirality owing to its high availability, and now it has been used as a chiral source for the preparation of chiral matter. In this review, the recent progress in the field of CPL-enabled chiral nanomaterials is summarized. Firstly, the recent advancements in the fabrication of chiral materials using circularly polarized light are described, focusing on the unique strategies. Secondly, an overview of the potential applications of chiral nanomaterials driven by CPL is provided, with a particular emphasis on biosensing, catalysis, and phototherapy. Finally, a perspective on the challenges in the field of CPL-enabled chiral nanomaterials is given.

Dual-Modal FexCuySe and Upconversion Nanoparticle Assemblies for Intracellular MicroRNA-21 Detection.

In situ quantification and imaging of low-level intracellular microRNAs (miRs) are important areas in biosensor research. Herein, DNA-driven FexCuySe@upconversion nanoparticle (UCNP) core@satellite nanostructures were developed to probe microRNA-21 (miR-21). FexCuySe@UCNP probes displayed dual signals: upconversion luminescence (UCL) and magnetic resonance imaging (MRI). In the presence of miR-21, the luminescence signal was restored and the T2 value was significantly increased because of dissociation of UCNPs from the assemblies. There was a good linear relationship between the dual signals and the expression levels of miR-21 in the range of 0.035-31.824 amol/ngRNA. The limit of detection (LOD) was 0.0058 amol/ngRNA for the luminescence intensity and 0.0182 amol/ngRNA for the MRI signal. This method opens a new avenue for intracellular miR-21 detection with high sensitivity and specificity.

Light-Induced Chiral Iron Copper Selenide Nanoparticles Prevent ß-Amyloidopathy In†Vivo.

The accumulation and deposition of ß-amyloid (Aß) plaques in the brain is considered a potential pathogenic mechanism underlying Alzheimer's disease (AD). Chiral l/d-Fex Cuy Se nanoparticles (NPs) were fabricated that interfer with the self-assembly of Aß42 monomers and trigger the Aß42 fibrils in dense structures to become looser monomers under 808 nm near-infrared (NIR) illumination. d-Fex Cuy Se NPs have a much higher affinity for Aß42 fibrils than l-Fex Cuy Se NPs and chiral Cu2-x Se NPs. The chiral Fex Cuy Se NPs also generate more reactive oxygen species (ROS) than chiral Cu2-x Se NPs under NIR-light irradiation. In living MN9D cells, d-NPs attenuate the adhesion of Aß42 to membranes and neuron loss after NIR treatment within 10 min without the photothermal effect. In-vivo experiments showed that d-Fex Cuy Se NPs provide an efficient protection against neuronal damage induced by the deposition of Aß42 and alleviate symptoms in a mouse model of AD, leading to the recovery of cognitive competence.