Synthesis, Characteristics, and Effect of Zinc Oxide and Silver Nanoparticles on the In Vitro Regeneration and Biochemical Profile of Chrysanthemum Adventitious Shoots

Fabrication of bimetallic Ag@ZnO nanocomposite and its anti-cancer activity on cervical cancer via impeding PI3K/AKT/mTOR pathway

INTRODUCTION

Bimetallic nanoparticles, specifically Zinc oxide (ZnO) and Silver (Ag), continue to much outperform other nanoparticles investigated for a variety of biological uses in the field of cancer therapy. This study introduces biosynthesis of bimetallic silver/zinc oxide nanocomposites (Ag@ZnO NCs) using the Crocus sativus extract and evaluates their anti-cancer properties against cervical cancer.

METHODS

The process of generating bimetallic nanoparticles (NPs), namely Ag@ZnO NCs, through the utilization of Crocus sativus extract proved to be uncomplicated and eco-friendly. Various methods, such as UV-vis, DLS, FTIR, EDX, and SEM analyses, were utilized to characterize the generated Ag@ZnO NCs. The MTT assay was employed to assess the cytotoxic properties of biosynthesized bimetallic Ag@ZnO NCs against the HeLa cervical cancer cell line. Moreover, the impact of Ag@ZnO NCs on HeLa cells was assessed by examining cell survival, ROS production, MMP levels, and induced apoptosis. Through western blot analysis, the expression levels of the PI3K, AKT, mTOR, Cyclin D, and CDK proteins seemed to be ascertained. Using flow cytometry, the cancer cells' progression through necrosis and apoptosis, in addition to the cell cycle analysis, were investigated.

RESULTS

Bimetallic Ag@ZnO NCs that were biosynthesized showed a high degree of stability, as demonstrated by the physicochemical assessments. The median size of the particles in these NCs was approximately 80-90 nm, and their zeta potential was -14.70 mV. AgNPs and ZnO were found, according to EDX data. Further, Ag@ZnO NCs hold promise as a potential treatment for cervical cancer. After 24 hours of treatment, a dosage of 5 µg/mL or higher resulted in a maximum inhibitory effect of 58 ± 2.9. The concurrent application of Ag/ZnO NPs to HeLa cells resulted in elevated apoptotic signals and a significant generation of reactive oxygen species (ROS). As a result, the bimettalic Ag@ZnO NCs treatment has been recognized as a chemotherapeutic intervention by inhibiting the production of PI3K, AKT, and mTOR-mediated regulation of propagation and cell cycle-regulating proteins.

CONCLUSIONS

The research yielded important insights into the cytotoxic etiology of biosynthesized bimetallic Ag@ZnO NCs against HeLa cells. The biosynthesized bimetallic Ag@ZnO NCs have a significant antitumor potential, which appears to be associated with the development of oxidative stress, which inhibits the development of the cell cycle and the proliferation of cells. Therefore, in the future, biosynthesized bimetallic Ag@ZnO NCs may be used as a powerful anticancer drug to treat cervical cancer.

Nanoparticle-mediated enhancement of plant cryopreservation: Cultivar-specific insights into morphogenesis and biochemical responses in Lamprocapnos spectabilis (L.) Fukuhara 'Gold Heart' and 'Valentine'

The integration of nanoparticles (NPs) holds promising potential to bring substantial advancements to plant cryopreservation, a crucial technique in biodiversity conservation. To date, little attention has been focused on using nanoparticles in cryobiology research. This study aimed to assess the effectiveness of NPs in enhancing the efficiency of plant cryopreservation. In-vitro-derived shoot tips of bleeding heart (Lamprocapnos spectabilis (L.) Fukuhara) 'Gold Heart' and 'Valentine' were used as the plant material. The encapsulation-vitrification cryopreservation protocol included preculture, encapsulation, dehydration, storage in liquid nitrogen, rewarming, and recovery steps. Gold (AuNPs), silver (AgNPs), or zinc oxide (ZnONPs) nanoparticles were added at various concentrations either into the preculture medium or the protective bead matrix during encapsulation. The explant survival and further morphogenic and biochemical events were studied. Results showed that the impact of NPs on cryopreservation outcomes was cultivar-specific. In the 'Valentine' cultivar, incorporating 5 ppm AgNPs within the alginate bead matrix significantly improved cryopreservation efficiency by up to 12%. On the other hand, the 'Gold Heart' cultivar benefited from alginate supplementation with 5 ppm AgNPs and 5-15 ppm ZnONPs, leading to an over 28% increase in the survival rate of shoot tips. Interestingly, adding NPs to the preculture medium was less effective and sometimes counterproductive, despite promoting greater shoot proliferation and elongation in 'Valentine' explants compared to the control. Moreover, nanoparticles often induced oxidative stress (and enhanced the activity of APX, GPOX, and SOD enzymes), which in turn affected the biosynthesis of plant primary and secondary metabolites. It was found that supplementation of preculture medium with higher concentration (15 ppm) of gold, silver and zinc oxide nanoparticles stimulated the production of plant pigments, but in a cultivar-dependent matter. Our study confirmed the beneficial action of nanoparticles during cryopreservation of plant tissues.

Unveiling the Potential of Bioinoculants and Nanoparticles in Sustainable Agriculture for Enhanced Plant Growth and Food Security

The increasing public concern over the negative impacts of chemical fertilizers and pesticides on food security and sustainability has led to exploring innovative methods that offer both environmental and agricultural benefits. One such innovative approach is using plant-growth-promoting bioinoculants that involve bacteria, fungi, and algae. These living microorganisms are applied to soil, seeds, or plant surfaces and can enhance plant development by increasing nutrient availability and defense against plant pathogens. However, the application of biofertilizers in the field faced many challenges and required conjunction with innovative delivering approaches. Nanotechnology has gained significant attention in recent years due to its numerous applications in various fields, such as medicine, drug development, catalysis, energy, and materials. Nanoparticles with small sizes and large surface areas (1-100 nm) have numerous potential functions. In sustainable agriculture, the development of nanochemicals has shown promise as agents for plant growth, fertilizers, and pesticides. The use of nanomaterials is being considered as a solution to control plant pests, including insects, fungi, and weeds. In the food industry, nanoparticles are used as antimicrobial agents in food packaging, with silver nanomaterials being particularly interesting. However, many nanoparticles (Ag, Fe, Cu, Si, Al, Zn, ZnO, TiO2, CeO2, Al2O3, and carbon nanotubes) have been reported to negatively affect plant growth. This review focuses on the effects of nanoparticles on beneficial plant bacteria and their ability to promote plant growth. Implementing novel sustainable strategies in agriculture, biofertilizers, and nanoparticles could be a promising solution to achieve sustainable food production while reducing the negative environmental impacts.