Zinc oxide nanoparticles produced with chia seed extract show promise against oral cancer cells
Researchers have reported laboratory evidence that zinc oxide nanoparticles produced through green synthesis using chia seed extract can selectively target oral cancer cells while also displaying antibacterial activity. The study, published August 2, 2026, in Scientific Reports, involved teams from King Faisal University, Princess Nourah bint Abdulrahman University and Shaqra University and received institutional support from King Faisal and Princess Nourah universities.
The work outlines a sustainable production route for nickel-doped zinc oxide nanoparticles and presents initial in vitro assessments against human oral cancer cells, normal oral cells and bacterial strains commonly implicated in oral infections. According to the paper, the particles formed largely spherical crystals with an average diameter near 72 nanometers under the laboratory conditions reported.
Green synthesis method and particle characterization
The research team used chia seed extract as a biological reducing and stabilizing agent in a green synthesis approach to fabricate nickel-doped zinc oxide nanoparticles. The protocol sought to avoid hazardous chemicals typically used in nanoparticle production and to leverage natural biomolecules for particle formation and stabilization.
Physicochemical characterization confirmed crystalline, predominantly spherical particles averaging about 72 nm in size, consistent with nanoscale behavior that can influence cellular uptake and surface interactions. The presence of nickel doping was reported by the authors as a modification intended to tune physicochemical and biological properties.
Laboratory efficacy against oral cancer cells and selectivity
In cytotoxicity assays, the nanoparticles reduced viability of human oral cancer cells at lower concentrations than required to affect normal oral cells. The concentration producing a 50 percent reduction in cancer cell viability (IC50) was reported as 139.9 micrograms per milliliter, compared with 284.6 micrograms per milliliter for normal oral cells, indicating higher sensitivity of the malignant cells under the experimental conditions.
Flow cytometry and cell-cycle analyses suggested the nanomaterial induced programmed cell death and cell-cycle disruption. About 50 percent of treated cancer cells entered early apoptosis and 22.5 percent progressed to late apoptosis, for a total apoptotic fraction of roughly 72.5 percent. The investigators also observed arrest of approximately 70.6 percent of cells at a pre-division phase, which signals inhibition of proliferative progression.
Antibacterial activity and biofilm inhibition
Beyond cancer cell assays, the report documents antibacterial activity, most notably against Staphylococcus aureus, a pathogen relevant to oral and wound infections. The nanoparticles reduced biofilm formation by up to 65 percent in laboratory tests, a finding the authors highlighted given the role of biofilms in increasing microbial resistance to therapies.
Gene expression analyses in treated bacteria indicated downregulation of genes associated with tissue adhesion, toxin production and virulence enhancement. Therefore, the material demonstrated both direct antimicrobial effects and interference with bacterial pathways that support infection severity and persistence.
Antioxidant activity and comparative performance
The study also measured antioxidant capacity in two assays and reported median inhibitory concentrations of 359 and 434 micrograms per milliliter, respectively, with lower antioxidant potency than ascorbic acid in the same tests. The authors framed this as moderate radical-scavenging activity that may contribute to biological responses but is not the primary mechanism of anticancer or antibacterial action.
Context: why combining anticancer and antibacterial functions matters
Combining anticancer activity with antibacterial and anti-biofilm effects addresses two intersecting clinical concerns. Oral cancers can coexist with chronic infections and biofilms that complicate treatment, while secondary infections can worsen patient outcomes. Therefore, an integrated platform that reduces tumor cell viability and controls pathogenic bacteria could have therapeutic advantages, according to the study’s rationale.
Furthermore, green synthesis aligns with growing interest in sustainable nanotechnology for biomedical use, reducing reliance on toxic reagents and potentially improving biocompatibility. However, the transition from in vitro promise to clinical application involves many additional steps.
Safety, limitations and next steps toward clinical relevance
The authors and peer reviewers underscore that the findings are preclinical and restricted to in vitro laboratory models. Key limitations include the need for comprehensive toxicity profiling in whole organisms, pharmacokinetics, biodistribution and dose-finding studies in animal models before any human trials. Therefore, in vivo toxicology and efficacy studies remain essential.
Regulatory pathways for nanoparticle-based therapeutics also require standardized manufacturing, reproducible characterization and long-term safety data. The researchers recommend follow-up studies to assess systemic toxicity, therapeutic windows, and delivery strategies that could concentrate effect in oral tissues while limiting off-target exposure.
What to watch next
Readers should look for subsequent publications from the research group reporting animal-model results, toxicity assessments and any refinement of the green synthesis method to improve yield and batch consistency. Progress toward preclinical proof-of-concept in vivo and eventual clinical feasibility studies will be the next milestones to determine whether these zinc oxide nanoparticles can advance beyond the laboratory stage.
Meanwhile, the study contributes to a broader research trend exploring multifunctional nanoparticles made by eco-friendly routes, coupling targeted anticancer effects with antibacterial and anti-biofilm properties. According to the report in Scientific Reports, the platform merits further investigation but is not yet suitable for therapeutic use without animal and clinical evaluation.