Allium sativum@AgNPs and Phyllanthus urinaria@AgNPs: a comparative analysis for antibacterial application

Bionanocomposites comprising mesoporous metal organic framework (ZIF-8) phytofabricated with Allium sativum as alternative nanomaterials to combat antimicrobial drug resistance

Green nanotechnology is one of the most expanding fields that provides numerous novel nanoparticle drug formulations with enhanced bioactivity performance. This study aims to synthesize mesoporous metal organic framework (ZIF-8) phytofabricated with the herb Allium sativum (As) as an indicator system for its antibacterial and antifungal impact. The successful synthesis of ZIF-8 as nanocomposite was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning coupled with energy-dispersive X-ray spectroscopy and transmission electron microscopy (SEM-EDX and TEM) that showed the textural retainment of ZIF-8 on composite formation with A. sativum. The nanocomposite, A. sativum extract, and ZIF-8 were subjected to antimicrobial assays against Shigella flexneri, Candida albicans, and Candida parapsilosis. The comparative results indicated the potential action of nanocomposite against the bacteria and both the Candida sps; however, the antifungal action against the Candida sps was more effective than the bacterium S. flexneri. The findings suggest that plants, being an important component of ecosystems, could be further explored for the novel drug discovery using green nanotechnology to enhance their impact on the drug-resistant pathogens.

Green Preparation and Antibacterial Activity Evaluation of AgNPs-Blumea balsamifera Oil Nanoemulsion

Bacterial infection is a thorny problem, and it is of great significance to developing green and efficient biological antibacterial agents that can replace antibiotics. This study aimed to rapidly prepare a new type of green antibacterial nanoemulsion containing silver nanoparticles in one step by using Blumea balsamifera oil (BBO) as an oil phase and tea saponin (TS) as a natural emulsifier and reducing agent. The optimum preparation conditions of the AgNPs@BBO-TS NE were determined, as well as its physicochemical properties and antibacterial activity in vitro being investigated. The results showed that the average particle size of the AgNPs@BBO-TS NE was 249.47 ± 6.23 nm, the PDI was 0.239 ± 0.003, and the zeta potential was -35.82 ± 4.26 mV. The produced AgNPs@BBO-TS NE showed good stability after centrifugation and 30-day storage. Moreover, the AgNPs@BBO-TS NE had an excellent antimicrobial effect on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. These results demonstrated that the AgNPs@BBO-TS NE produced in this study can be used as an efficient and green antibacterial agent in the biomedical field.

Inflammation-Responsive Hydrogel Accelerates Diabetic Wound Healing through Immunoregulation and Enhanced Angiogenesis

Angiogenesis is a prominent component during the highly regulated process of wound healing. The application of exogenous vascular endothelial growth factor (VEGF) has shown considerable potential in facilitating angiogenesis. However, its effectiveness is often curtailed due to chronic inflammation and severe oxidative stress in diabetic wounds. Herein, an inflammation-responsive hydrogel incorporating Prussian blue nanoparticles (PBNPs) is designed to augment the angiogenic efficacy of VEGF. Specifically, the rapid release of PBNPs from the hydrogel under inflammatory conditions effectively alleviates the oxidative stress of the wound, therefore reprogramming the immune microenvironment to preserve the bioactivity of VEGF for enhanced angiogenesis. In vitro and in vivo studies reveal that the PBNPs and VEGF co-loaded hydrogel is biocompatible and possesses effective anti-inflammatory properties, thereby facilitating angiogenesis to accelerate the wound healing process in a type 2 diabetic mouse model.

Stixis scandens leaf extract-loading ZnO nanoparticles for porcine epidemic diarrhea virus (PEDV) treatment

Porcine epidemic diarrhea (PED) is one of the diseases that causes great losses for livestock farmers. Because vaccines against the disease are not very effective, there is a great demand for biological products with effective resistance to PED virus (PEDV). One of the most important trends today is the use of active ingredients from nature in animal husbandry. This study aimed to create an effective agent against PEDV from the extract of Stixis scandens, which has been shown to inhibit PEDV. The aqueous (denoted as TCN) and ethanolic extracts (denoted as TCC) of Stixis scandens leaves were first prepared and then qualitatively analyzed for their chemical compositions. The TCN was used to synthesize ZnO nanoparticles (NPs) at various sizes from 20 to 120 nm. Subsequently, TCC was loaded on ZnO NPs to form ZnO-extract nanoformulations with an extract loading content of 5.8-7.6%. Total polyphenols (TP) and total alkaloids (TA) in TCC were 38.51 ± 0.25 μg GAE per mg and 22.37 ± 0.41 μg AtrE per mg, respectively. TP was less loaded but more released from the nanoformulations than TA. The A1T nanoformulation, containing only 7.6% extract, had a minimum PEDV inhibitory concentration of 3.9 μg mL-1, which was comparable to that of TCC. The experiments confirmed that the nanoformulations are promising for PEDV inhibition applications.

Multilayer immobilizing of denitrifying Bacillus sp. and TiO2-AgNPs on floating expanded clay carrier for co-treatment of nitrite and pathogens in aquaculture

Nitrite contamination and the spread of pathogens can seriously degrade water quality. To simultaneously control these factors, an innovative approach of fabricating a remediation agent that contained denitrifying bacteria and TiO2-AgNPs co-immobilized on floating expanded clay (EC) was proposed in this study. The EC was fabricated from a mixture of clay and rice husk through pyrolysis at a high temperature of 1200 °C, followed by a rapid cooling step to create a porous structure for the material. TiO2NPs were modified with Ag to shift the absorbance threshold of TiO2-AgNPs into the visible region of 700-800 nm. The experimental results showed that the stirring speed of 250 rpm was suitable for immobilizing TiO2-AgNPs on EC and achieved the highest Ti and Ag content of 639.38 ± 3.04 and 200.51 ± 3.71 ppm, respectively. Coating TiO2-Ag/EC with chitosan (0.5%) significantly reduced the detachment level of immobilized TiO2-AgNPs compared to that of the material with no coating. In particular, this functionalized material inhibited 99.93 ± 0.1% of Vibrio parahaemolyticus pathogen but did not adversely affect the denitrifying bacteria after 2 h of visible light irradiation. Based on the electrostatic bond between oppositely charged polymers, the denitrifying bacteria, Bacillus sp., in alginate solution was successfully immobilized on the chitosan-coated TiO2-Ag/EC with a bacteria density of (76.67 ± 9.43) × 107 CFU g-1, retaining its nitrite removal efficiency at 99.0 ± 0.27% through six treatment cycles. These findings provide solid evidence for further investigating the combination of biodegradation and photodegradation in wastewater treatment.