In a comparative laboratory investigation evaluating green nanotechnology approaches, researchers synthesized zinc oxide and cerium dioxide nanoparticles using leaf extract from Abrus precatorius as a dual reducing and stabilizing agent, identifying distinct antioxidant, antibacterial, cytocompatibility, and cellular wound-healing properties between the two metal oxide nanostructures. The study was structured to address the limited comparative research available regarding the plant-mediated synthesis of zinc oxide nanoparticles and cerium dioxide nanoparticles utilizing this specific botanical source. Characterization and screening protocols demonstrated that while cerium dioxide nanoparticles exhibited superior free-radical scavenging capacity, zinc oxide nanoparticles demonstrated substantially higher antibacterial performance against Gram-positive pathogens alongside strong wound-closure acceleration in cultured fibroblast cells.

Material characterization of the synthesized nanomaterials confirmed the successful generation of highly crystalline and thermally stable metal oxide nanostructures through the environmentally sustainable plant-mediated synthesis route. Structural and physical analyses revealed notable dimensional differences between the two formulations, with the zinc oxide nanoparticles displaying an average particle size of 36 nanometers, whereas the cerium dioxide nanoparticles formed smaller structures with an average particle size of 22.6 nanometers. Furthermore, optical evaluations established optical band gap energies of 3.31 electron volts for the zinc oxide nanoparticles and 3.54 electron volts for the cerium dioxide nanoparticles, illustrating clear physicochemical distinctions arising from the botanical dual reducing and stabilizing process.

Biological assessment of antioxidant potential showed marked variations in scavenging capacity between the two plant-derived metal oxides, with cerium dioxide nanoparticles displaying enhanced efficiency compared to their zinc oxide counterparts. In experimental testing, cerium dioxide nanoparticles achieved a half-maximal inhibitory concentration of 19 micrograms per milliliter, demonstrating stronger antioxidant action than the zinc oxide nanoparticles, which recorded a half-maximal inhibitory concentration of 27 micrograms per milliliter. This comparative metric underscores the specific efficacy of the cerium dioxide formulation in processes requiring free-radical neutralization under the assessed in vitro parameters.

Conversely, antimicrobial assays demonstrated that zinc oxide nanoparticles possessed superior antibacterial potency, showing pronounced inhibitory activity particularly against tested Gram-positive bacterial pathogens. At a concentration of 1000 micrograms per milliliter, zinc oxide nanoparticles produced a zone of inhibition measuring 12.0 ± 0.96 millimeters against Enterococcus faecalis. When tested against Streptococcus mutans across escalating concentrations, the zinc oxide nanoparticles generated zones of inhibition measuring 11.0 ± 0.50 millimeters at 250 micrograms per milliliter, 12.0 ± 0.58 millimeters at 500 micrograms per milliliter, and 14.0 ± 0.45 millimeters at 1000 micrograms per milliliter.

The antibacterial efficacy of the zinc oxide nanoparticles was similarly pronounced against Staphylococcus aureus, yielding concentration-dependent antibacterial responses across all tested levels. Assays recorded zones of inhibition of 12.0 ± 0.56 millimeters at 250 micrograms per milliliter, 16.0 ± 0.63 millimeters at 500 micrograms per milliliter, and 18.0 ± 0.57 millimeters at 1000 micrograms per milliliter. These measurable growth-inhibitory responses confirmed the broad concentration-dependent efficacy of the synthesized zinc oxide nanostructures against prominent Gram-positive bacterial strains relative to the comparative material.

In vitro cytocompatibility evaluations conducted on human embryonic kidney HEK-293 cells established baseline cellular safety profiles for both nanomaterials when exposed at a concentration of 200 micrograms per milliliter. Exposure to the plant-mediated zinc oxide nanoparticles resulted in a cell viability rate of 55.0 ± 0.55 percent, whereas the cerium dioxide nanoparticles exhibited higher cytocompatibility, retaining a cell viability rate of 70.0 ± 0.60 percent at the equivalent concentration threshold. These measurements established the comparative in vitro cellular tolerance parameters for both metal oxide formations.

Building on its balanced antibacterial properties and acceptable cellular compatibility, the zinc oxide nanoparticle formulation was subsequently investigated for regenerative potential in cellular wound-healing assays. When administered in vitro, the zinc oxide nanoparticles greatly enhanced wound closure rates in NCTC clone 929 (L929) fibroblast cells. By directly linking distinct physicochemical traits such as particle dimensions and optical band gap values to specific biological behaviors, the comparative findings offer an evidence-based foundation for selecting and developing plant-mediated metal oxide nanomaterials tailored to targeted biomedical applications.

Subject of Research: Comparative biological and physicochemical evaluation of plant-mediated zinc oxide and cerium dioxide nanoparticles

Article Title: Comparative evaluation of Abrus precatorius mediated ZnO and CeO2 nanoparticles for biological applications

Article References: Shyam, A., Chandran, S. S., & George, B. (2026). Comparative evaluation of Abrus precatorius mediated ZnO and CeO2 nanoparticles for biological applications. Discover Materials. https://doi.org/10.1007/s43939-026-01036-0

Image Credits: AI Generated

DOI: 10.1007/s43939-026-01036-0

Keywords: Abrus precatorius, zinc oxide nanoparticles, cerium dioxide nanoparticles, green synthesis, plant extract, nanotechnology, antibacterial activity, antioxidant activity, cytocompatibility, wound healing, HEK-293 cells, L929 fibroblast cells, Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, band gap energy