A two-in-one molybdenum disulfide-chitosan nanoparticles system for activating plant defense mechanisms and reactive oxygen species to treat Citrus Huanglongbing.

Citrus Huanglongbing (HLB) poses an enormous challenge to Citrus cultivation worldwide, necessitating groundbreaking interventions beyond conventional pharmaceutical methods. In this study, we propose molybdenum disulfide-chitosan nanoparticles (MoS2-CS NPs) through electrostatic adsorption, preserving the plant-beneficial properties of molybdenum disulfide (MoS2), while enhancing its antibacterial effectiveness through chitosan modification. MoS2-CS NPs exhibited significant antibacterial efficacy against RM1021, and the closest relatives to Candidatus Liberibacter asiaticus (CLas), Erwinia carotovora, and Xanthomonas citri achieved survival rates of 7.40 % ±â€¯1.74 %, 8.94 % ±â€¯1.40 %, and 6.41 % ±â€¯0.56 %, respectively. In vivo results showed, CLas survival rate of 10.42 % ±â€¯3.51 %. Furthermore, treatment with MoS2-CS NPs resulted in an increase in chlorophyll and carotenoid content. Concomitantly, a significant reduction in malondialdehyde (MDA), soluble sugar, hydrogen peroxide (H2O2), and starch contents was also observed. Mechanistically, MoS2-CS NPs enhanced the activity of antioxidant-related enzymes by upregulating the expression of antioxidant genes, thereby galvanizing the antioxidant system to alleviate oxidative stress. Collectively, this dual functionality-combining direct antibacterial action with the activation of plant defense mechanisms-marks a promising strategy for managing Citrus Huanglongbing and suggests potential agricultural applications for MoS2-based antibacterial treatments.

Fabrication of nanogels to improve the toxicity and persistence of cycloxaprid against Diaphorina citri, the vector of citrus huanglongbing.

INTRODUCTION: Diaphorina citri is the most serious pest of citrus worldwide because it is the natural insect vector of huanglongbing. Cycloxaprid (Cyc) was highly toxic to D. citri. However, the poor solubility and stability had limited its development. OBJECTIVES: In order to improve the insecticidal effect and stability to harsh climatic conditions of Cyc. METHODS: Cyc was chosen as the representative pesticide, 4,4'-methylenebis (phenyl isocyanate), PEG-600 and n-butanol were used to prepare sustained-release nano-gelation particles (Cyc@NGs). RESULTS: Cyc@NGs enhance the toxicity of Cyc more than 3 folds. Furthermore, Cyc@NGs showed excellent anti-rain and anti-UV capacity. After being exposed to ultraviolet light for 12 h, Cyc decreased by 100 %, while the insecticide content of Cyc@NGs only decreased by 25 %. Additionally, Cyc@NGs possessed better wettability on citrus leaves, mainly benefitting from its lower contact angle on citrus leaves. Moreover, FITC-labeled nano-gelation particles (FITC-NGs) exhibited high capability to penetrate and enrich in citrus leaf tissue and D. citri midgut. Consequently, NGs promoted the translocation and durability of insecticides, thereby, increasing the insecticidal activity. The results suggested that nano-gelation particle is a promising platform to deliver insecticides and Cyc@NGs would be the suitable candidate for the effective management of D. citri.

Gene editing of Duchenne muscular dystrophy using biomineralization-based spCas9 variant nanoparticles.

The CRISPR/Cas9 mediated genome editing have provided a promising strategy to correct multiple mutations of Duchenne muscular dystrophy (DMD). However, the delivery of CRISPR/Cas9 system into mammalian cell for DMD gene editing mainly relies on adeno associated virus (AAV)-mediated transport. Meanwhile, the protospacer adjacent motif (PAM) requirement of wild-typed Cas9 protein causing the target sites for exon splice acceptor site are restricted to limited regions. Here, we developed a biomineralized PAMLess Cas9 (SpRY) variant nanoparticles (Bm-SpRY NPs) for DMD gene editing in vitro and in vivo. This method described a facile synthesis of biomineralized NPs with high SpRY pDNA encapsulation efficiency. In vitro results show that the Bm-SpRY NPs have the obvious advantages of well biocompatibility and protecting SpRY pDNA from enzyme degradation and efficient delivery under high serum condition. Cell studies demonstrated that Bm-SpRY NPs enable rapid cellular uptake, endo-lysosomes escape and nucleus transport. Meanwhiles, the DMD gene editing via Bm-SpRY NPs pathway is transient process without genomic integration. We evaluated multiple target regions with different PAMs for the DMD exon 51 splice acceptor site through Bm-SpRY NPs method and found that the target region with TAG PAM has the highest editing efficiency and significant preferential mutation. In vivo results show that intramuscular injection of Bm-SpRY NPs enable DMD gene mutation in muscle tissue without tissue damage. This study may extend the advanced application of CRISPR system for DMD therapy. STATEMENT OF SIGNIFICANCE: The gene editing technology of CRISPR/Cas9 provides an effective treatment strategy for the Duchenne muscular dystrophy (DMD) therapy. However, the delivery of CRISPR system in mammalian cell mainly relies on viral mediated transport and the NGG or NAG requirement of wild-typed Cas9 protein limits the target region in DMD gene. Here, the present study provides a biomineralized PAM Less Cas9 (SpRY) variant nanoparticles (Bm-SpRY NPs) for DMD gene editing in vitro and in vivo. This study may extend the application of CRISPR system for DMD gene therapy.

Efficient Gene Silencing in Intact Plant Cells Using siRNA Delivered By Functional Graphene Oxide Nanoparticles.

Delivery of small interfering RNA (siRNA) to intact plants for gene silencing mainly relies on viral vectors and Agrobacterium-mediated transformation due to the barrier of intact plant cell wall. Here, we reported that polymer functionalized graphene oxide nanoparticles (GONs) enable siRNA transfer into intact plant cells and bring about efficient gene silencing. We found that sheeted GONs could efficiently load siRNA to form small sized, near-spheroidal GONs-siRNA complex, which could be across the cell wall and internalize in the plant cell. The GONs-siRNA exhibited transient and strong silencing (97.2 % efficiency) in plant tissues at 24 h after treatment and returned to normal level at 5 days after treatment. This method has the obvious advantages of efficient, transient, simple, stability and well biocompatibility, which should greatly stimulate the application of nanomaterials as gene-engineering tools in plant research.

Tea Polyphenol Liposomes Overcome Gastric Mucus to Treat Helicobacter Pylori Infection and Enhance the Intestinal Microenvironment.

Infection with Helicobacter pylori (Hp) is one of the leading causes of stomach cancer. The ability to treat Hp infection is hampered by a lack of stomach gastric acid environment. This work introduces a nanoliposome that can rapidly adjust the gastric acid environment to ensure a drug's optimal efficacy. We introduce CaCO3@Fe-TP@EggPC nanoliposomes (CTE NLs) that are composed of Fe3+ and tea polyphenols (TPs) forming complexes on the surface of internal CaCO3 and then with lecithin producing a phospholipid bilayer on the polyphenols' outer surface. Through the action of iron-TP chelate, the phospholipid layer can fuse with the bacterial membrane to eliminate Hp. Furthermore, CaCO3 can promptly consume the excessive gastric acid, ensuring an ideal operating environment for the chelate. TPs, on the other hand, can improve the inflammation and gut microbes in the body. The experimental results show that CTE NLs can quickly consume protons in the stomach and reduce the bacterial burden by 1.2 orders of magnitude while reducing the inflammatory factors in the body. The biosafety evaluation revealed that nanoliposomes have good biocompatibility and provide a new strategy for treating Hp infection.

Gastric Acid Powered Nanomotors Release Antibiotics for In Vivo Treatment of Helicobacter pylori Infection.

Helicobacter pylori (H. pylori) infection has ≈75% probability of causing gastric cancer, so it is considered to be the strongest single risk factor for gastric malignancies. However, the harsh gastric acid environment has created obstacles to medical treatment. This work reports a nanomotor with a bottle-shaped container that can be loaded with small molecules of clarithromycin, nano calcium peroxide (CaO2 ), and Pt nanoparticles (Pt NPs) by ultrasound. Nanomotors can quickly consume gastric acid through the chemical reaction of CaO2 to temporarily neutralize gastric acid. The product hydrogen peroxide (H2 O2 ) is catalytically decomposed into a large amount of oxygen (O2 ) by Pt NPs. The local concentration gradient of O2 bubbles causes it to be expelled from the nanobottles through a narrow opening, and then push the nanobottles forward to provide maximum release and prodrug efficacy. Experiments in animal models show that 15 mg nanomotors can safely and quickly neutralize gastric acid in the stomach and simultaneously release prodrugs to achieve good therapeutic effects without causing acute toxicity. H. pylori burden in mice was 2.6 orders of magnitude lower than that in the control group. The stomach returns to normal pH within 1 d after administration.

Photothermally triggered nitric oxide nanogenerator targeting type IV pili for precise therapy of bacterial infections.

Nitric oxide (NO) is an important biological messenger involved in the treatment of bacterial infections, but its controlled and targeted release in bacterial infections remains a major challenge. Herein, an intelligent NO nanogenerator triggered by near-infrared (NIR) light is constructed for targeted treatment of P. aeruginosa bacterial infection. Since maleimide can recognize and attach to the pilus of T4P of P. aeruginosa, we adopt this strategy to achieve the accurate release of therapeutic drugs at the infection site, i.e., after maleimide targets Gram-negative bacteria, the SNP@MOF@Au-Mal nanogenerator will release NO and generate ROS in situ from the inorganic photosensitizer gold nanoparticles under NIR irradiation to achieve synergistic antibacterial effect. In vivo experiments proved that the bacterial burden on the wound was reduced by 97.7%. Additionally, the nanogenerator was shown to promote the secretion of growth factors, which play a key role in regulating inflammation and inducing angiogenesis. This strategy has the advantage of generating a high concentration of NO in situ to promote the transfer of more NO and its derivatives (N2O3, ONOO-) to bacteria, thereby significantly improving the antibacterial effect. The multifunctional antibacterial platform has been demonstrated as a good carrier for gas therapy because of its simple and efficient gas release performance, indicating its great potential for the treatment of drug-resistant bacterial infections.