ACS APPLIED MATERIALS&INTERFACES: Conquer the dawn of Alzheimer's disease!

Alzheimer's disease (AD), commonly known as Alzheimer's disease, is a neurodegenerative disease, a mitochondrial dysfunction closely related to amyloid fibrils (Aβ) deposition and neurofibrillary tangles (NFTs)
.

Drugs for the treatment of AD have been being developed, but the effects are very limited.

In previous studies, it was found that oxidative stress is a common physiological variation in early AD neurons, and it is closely related to the formation of Aβ and NFTs
.

Simply put, Aβ and intracellular reactive oxygen species are in a synergistic and incremental relationship, which can further increase the intracellular reactive oxygen species ROS production, change the mitochondrial membrane potential, and disrupt Ca2+ homeostasis.

In October 2021, a research team from Jinan University published a paper "A Functionalized Octahedral Palladium Nanozyme as a Radical Scavenger for Ameliorating Alzheimer's Disease" in "ACS APPLIED MATERIALS&INTERFACES"
.

In this study, the researchers designed and prepared an octahedral palladium (Pd) nanoenzyme composite material (Pd@PEG@ Bor).

(Illustration: Schematic diagram of the experimental principle of the material used to treat AD mice)

(Illustration: Schematic diagram of the experimental principle of the material used to treat AD mice) (Illustration: Schematic diagram of the experimental principle of material used to treat AD mice)

The researchers characterized the biological properties of the composite material from the aspects of anti-oxidation, biocompatibility, elimination of ROS, blood-brain barrier penetration experiment, mouse behavior, etc.
, and proved that the composite material can improve the penetration of blood brain The efficiency of the barrier and targeting neurons, eliminate excessive ROS in cells, maintain mitochondrial membrane potential and calcium ion levels, inhibit the production and aggregation of Aβ, reduce neuroinflammation, protect neurons, and further improve the cognition of AD mice Obstacles can effectively alleviate the symptoms of AD
.

(1) Antioxidant activity test
.

The experimental results show that the individual Pd nanoparticles (Pd NPs) and composite materials (Pd@PEG@Bor) have strong scavenging ability to hydroxyl radicals and singlet reactive oxygen species, and the higher the concentration, the stronger the scavenging ability

(Legend: Pd NPs and Pd@PEG@Bor have the ability to remove ROS
.

(A) Contains ·OH, Pd NPs (20 μg/mL) and Pd@PEG@Bor (20 μg/mL); (B) different Concentrations of Pd@PEG@Bor samples and ·OH; (C) samples containing 1O2, Pd NPs (20 μg/mL) and Pd@PEG@Bor (20μg/mL); (D) samples containing 1O2 and different concentrations of Pd@PEG @Bor;)

(Legend: Pd NPs and Pd@PEG@Bor have the ability to remove ROS

(Legend: Pd NPs and Pd@PEG@Bor biocompatibility experiment
.

(A) SH-SY5Y cell uptake of RBT, Pd@RBT and Pd@PEG@Bor@ RBT (scale bar = 20 μm)

(Legend: Pd NPs and Pd@PEG@Bor biocompatibility experiment

(Illustration: Pd@PEG@Bor eliminates reactive oxygen species and reduces Aβ content in vitro)

(Picture note: Pd@PEG@Bor eliminates reactive oxygen species and decreases Aβ content in vitro) (Picture note: Pd@PEG@Bor eliminates reactive oxygen species and decreases Aβ content in vitro)

(4) The ability of Pd@PEG@Bor to cross the blood-brain barrier in vitro and in vivo
.

The researchers used RBT as a probe to compare the distribution of Pd NPs and Pd@PEG@Bor in the mouse parietal cortex and hippocampus using a confocal laser microscope

(Illustration: Pd@PEG@Bor's ability to cross the blood-brain barrier in vitro and in vivo
.

(A) Schematic diagram of the blood-brain barrier model
.
(B) In vitro blood-brain barrier permeability of Pd NPs and Pd@PEG@Bor
.
( C) The distribution of Pd@RBT and Pd@PEG@Bor@RBT in the cerebral cortex of normal mice (D) The distribution of Pd@RBT and Pd@PEG@Bor@RBT in the hippocampus of the normal mouse brain)

(Illustration: Pd@PEG@Bor's ability to cross the blood-brain barrier in vitro and in vivo
.
(A) Schematic diagram of the blood-brain barrier model
.
(B) In vitro blood-brain barrier permeability of Pd NPs and Pd@PEG@Bor
.
( C) The distribution of Pd@RBT and Pd@PEG@Bor@RBT in the cerebral cortex of normal mice (D) The distribution of Pd@RBT and Pd@PEG@Bor@RBT in the hippocampus of the normal mouse brain) (Figure note: Pd @PEG@Bor's ability to cross the blood-brain barrier in vitro and in vivo
.
(A) Schematic diagram of the blood-brain barrier model
.
(B) In vitro blood-brain barrier permeability of Pd NPs and Pd@PEG@Bor
.
(C) Pd@RBT The distribution of Pd@PEG@Bor@RBT in the cerebral cortex of normal mice (D) The distribution of Pd@RBT and Pd@PEG@Bor@RBT in the hippocampus of the normal mouse brain)

(5) Behavioral experiment of AD mice
.
AD mice showed obvious anxiety and depression behaviors in the experiment
.
However, after intravenous injection of Pd@PEG@Bor, anxiety and depression behavior improved
.
In other behavioral experiments, it was proved that Pd@PEG@Bor treatment can improve the research ability and memory ability of AD mice
.
In conclusion, behavioral experiments in mice show that composite materials can effectively alleviate cognitive deficits in AD mice
.

Summary: Researchers have synthesized a new type of nanocomposite material Pd@PEG@Bor, which can be used to improve Alzheimer’s disease, reduce Aβ levels, improve neuroinflammation, improve learning and memory, and find a way to overcome this difficult disease.
A ray of light!

Original source:

Original source:

Zhi Jia, Xiaoyu Yuan, Ji-an Wei, et al.
A Functionalized Octahedral Palladium Nanozyme as a Radical Scavenger for Ameliorating Alzheimer's Disease .
ACS Appl.
Mater.
Interfaces 2021.

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