Search

BACKGROUND: Owing to their surface modifiability, smart mesoporous silica nanoparticles (MSNs) can be designed to respond to plant disease‐microenvironmental stimuli, thereby achieving on‐demand release of active ingredients to control disease by effectively improving citral (CT) stability. RESULTS: A pH/chitinase dual stimuli‐responsive essential oil‐delivery system (CT@HMS@CH/TA) was successfully fabricated by encapsulating CT in hollow mesoporous silica (HMS), and coating with tannic acid (TA) and chitosan (CH) within HMS by using the layer‐by‐layer assembly technique (LbL). CT@HMS@CH/TA with an average particle size of 125.12 ± 0.12 nm and a hollow mesoporous nanostructure showed high CT‐loading efficiency (16.58% ± 0.17%). The photodegradation rate of CT@HMS@CH/TA under UV irradiation (48 h) was only 15.31%, indicating a 3.34‐fold UV stability improvement. CT@HMS@CH/TA exhibited a higher CT release rate in response to acidic pH and the presence of chitinase, simulating the prevailing conditions as Magnaporthe oryzae infection. Furthermore, CT@HMS@CH/TA exhibited better adhesion without affecting normal rice growth, significantly upregulating chitinase gene expression and enhancing chitinase activity on M. oryzae, thus enhancing CT antifungal activity. CONCLUSION: CT@HMS@CH/TA improved CT stability and showed intelligent, controlled release‐performance and higher antifungal efficacy, thus providing a new strategy for efficient application of essential oils for green control of rice blast disease. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A sodium alginate/silk sericin (SA/SS) film was modified with glycerin (GI) and Polygonatum sibiricum polysaccharide@silver nanoparticles (PSP@AgNPs) to create a SA/SS/GI/PSP@AgNP composite film with antibacterial and antioxidant properties. The physicochemical properties of the SA/SS/GI/PSP@AgNP composite film were analyzed, and its cytocompatibility, antioxidant activity, and antibacterial properties were investigated. The optimum conditions for the preparation of the SA/SS/GI/PSP@AgNP composite film were 2 % SA, 2 % SS, 20 % GI, and 40 μg/mL of PSP@AgNPs. The addition of GI improved the surface smoothness of the composite films, while the presence of PSP@AgNPs did not significantly alter it. Spectroscopic characterization demonstrated that GI and PSP@AgNPs were physically bound to SA/SS. Approximately 53 % of the PSP@AgNP was released from the SA/SS/GI/PSP@AgNP composite film over 24 h of soaking in aqueous solution. The resulting leaching solution did not cause hemolysis or cytotoxicity, indicating its biocompatibility. Additionally, the SA/SS/GI/PSP@AgNP composite film exhibited strong antioxidant and antibacterial properties, and it promoted healing of mouse wounds infected with Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

The selection of effective antibiotics is becoming increasingly limited due to the emergence of bacterial resistance. Designing and developing nanoscale antibacterials is a strategy for effectively addressing the antibiotic crisis. In this work, AgNPs@AMP nanoparticles were synthesized to take advantage of the synergistic antibacterial activity of the (LLRR)3 antimicrobial peptide (AMP) and silver nanoparticles (AgNPs). Based on morphological structure characterization and biocompatibility analysis, the inhibitory properties of AgNPs@AMP on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were evaluated. The results demonstrated that AMP and AgNPs were physically bound to form AgNPs@AMP nanoparticles, which had better solution stability, improved nanomaterial properties, and overcame the hemolytic activity of AMP and the cytotoxicity of AgNPs. The inhibitory activity of AgNPs@AMP against E. coli and S. aureus was significantly higher than that of AMP and AgNPs. It was capable of disrupting the morphology and internal structure of cells, damaging the cell membrane, and inhibiting the activity of enzymes related to the material-energy metabolism of the tricarboxylic acid cycle. Compared to AMP and AgNPs, AgNPs@AMP were found to effectively inhibit the infection of mouse wounds and promote their healing. Therefore, AMP-modified AgNPs can enhance their biocompatibility and antibacterial activity, and they can be further developed as a potential antimicrobial agent. [ABSTRACT FROM AUTHOR]