Background: Nitric oxide (NO) is an antimicrobial and anti-biofilm agent with significant potential for combating biofilm-associated infections and antibiotic resistance. However, owing to its high reactivity due to the possession of a free radical and short half-life (1–5 s), the practical application of NO in clinical settings is challenging. Objectives: This review explores the development of NO-releasing nanoparticles that provide a controlled, targeted delivery system for NO, enhancing its antimicrobial efficacy while minimizing toxicity. The review discusses various NO donors, nanoparticle platforms, and how NO disrupts biofilm formation and eradicates pathogens. Additionally, we examine the highly encouraging and inspiring results of NO-releasing nanoparticles against multidrug-resistant strains and their applications in medical and environmental contexts. This review highlights the promising role of NO-based nanotechnologies in overcoming the challenges posed by increasing antibiotic resistance and biofilm-associated infections. Conclusions: Although NO donors and nanoparticle delivery systems show great potential for antimicrobial and anti-biofilm uses, addressing challenges related to controlled release, toxicity, biofilm penetration, resistance, and clinical application is crucial.

Chlorpyrifos (CP) is a globally used pesticide with acute toxicity. This work studied the photocatalytic degradation of CP using TiO₂, ZnO nanoparticles, and nanocomposites of TiO₂ and ZnO supported on SPIONs (SPION@SiO₂@TiO₂ and SPION@SiO₂@ZnO). The nanocomposites were synthesized by multi-step incipient wetness impregnation. The effects of the initial pH, catalyst type, and dose were evaluated. The nanocomposites of SPION@SiO₂@TiO₂ and SPION@SiO₂@ZnO showed higher CP photodegradation levels than free nanoparticles, reaching 95.6% and 82.3%, respectively, at pH 7. The findings indicate that iron oxide, as a support material for TiO₂ and ZnO, extended absorption edges and delayed the electron–hole recombination of the nanocomposites, improving their photocatalytic efficiency. At the same time, these nanocomposites, especially SPION@SiO₂@TiO₂, showed efficient degradation of 3,5,6-trichloropyridinol (TCP), one of the final metabolites of CP. The stability and reuse of this nanocomposite were also evaluated, with 74.6% efficiency found after six cycles. Therefore, this nanomaterial represents an eco-friendly, reusable, and effective alternative for the degradation of chlorpyrifos in wastewater treatment.

Background/Objectives: Chitosan-based films incorporating green-synthesized silver nanoparticles AgNPs) or copper oxide nanoparticles (CuONPs) were developed to compare their selective antimicrobial action for topical applications. While AgNPs are known for broad-spectrum activity, this study hypothesized that CuONPs would exhibit superior, targeted efficacy against the acne-associated bacterium Cutibacterium acnes. Methods: Nanoparticles were synthesized using Camellia sinensis extract and characterized. Antimicrobial activity was evaluated using Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. Chitosan films containing AgNPs or CuONPs were further tested for selective antimicrobial activity and fibroblast cytocompatibility. Results: AgNPs showed strong activity against Escherichia coli and Staphylococcus aureus (MIC = 15 µg/mL) but were less effective against C. acnes (MIC = 125 µg/mL). In contrast, CuONPs demonstrated selective efficacy against C. acnes (MIC = 62 µg/mL; MBC = 125 µg/mL). When incorporated into chitosan films, AgNPs@CHI inhibited E. coli (35 mm halo) and S. aureus (30 mm), whereas CuONPs@CHI were selectively effective against C. acnes (45 mm). All films preserved fibroblast viability above the 70% ISO 10993-5 threshold. Conclusions: CuONPs@CHI films validated selective anti-C. acnes performance, highlighting their promise for targeted anti-acne therapies, while AgNPs@CHI films served as effective broad-spectrum antimicrobial barriers.revealed that AgNPs were potent against Escherichia coli and Staphylococcus aureus (MIC = 15 µg/mL) but less effective against C. acnes (MIC = 125 µg/mL). Conversely, CuONPs demonstrated a marked selective advantage against C. acnes (MIC = 62 µg/mL; MBC = 125 µg/mL). When incorporated into chitosan films, AgNPs@CHI films inhibited E. coli (35 mm halo) and S. aureus (30 mm), whereas CuONPs@CHI films were selectively effective only against C. acnes (45 mm), confirming the targeted performance. All films maintained fibroblast viability above the 70% ISO 10993-5 cytotoxicity threshold. These findings validate the selective action of CuONPs@CHI films, positioning them as a promising biomaterial for targeted anti-acne therapies, while AgNPs@CHI films serve as effective broad-spectrum antimicrobial barriers.

Nitric oxide (NO) is a multifunctional signaling molecule in plants, playing key roles in germination, microbial symbiosis, and nodule formation. However, its instability requires innovative approaches, such as using nanoencapsulated NO donors, to prolong its effects. This study evaluated the impact of treating soybean (Glycine max) seeds with the NO donor S-nitrosoglutathione (GSNO), encapsulated in polymeric nanoparticles, on the germination, nodulation, and plant growth. Seeds were treated with free GSNO, chitosan nanoparticles with/without NO (NP CS-GSNO/NP CS-GSH, where GSH is glutathione, the NO donor precursor), and alginate nanoparticles with/without NO (NP Al-GSNO/NP Al-GSH). Chitosan nanoparticles (positive zeta potential) were smaller and released NO faster compared with alginate nanoparticles (negative zeta potential). The seed treatment with NP CS-GSNO (1 mM, related to GSNO concentration) significantly improved germination percentage, root length, number of secondary roots, and dry root mass of soybean compared with the control. Conversely, NP CS-GSH resulted in decreased root and shoot length. NP Al-GSNO enhanced shoot dry mass and increased the number of secondary roots by approximately threefold at the highest concentrations. NP CS-GSNO, NP Al-GSNO, and NP Al-GSH increased S-nitrosothiol levels in the roots by approximately fourfold compared with the control. However, NP CS-GSNO was the only treatment that increased the nodule dry mass of soybean plants. Therefore, our results indicate the potential of chitosan nanoparticles to improve the application of NO donors in soybean seeds.

Zinc is an important nutrient for several plants and humans. Nitric oxide (NO) is a free radical that is important to biological processes that mediate the growth and mitigation of biotic and abiotic stresses in plants. The present study investigated the enzymatic and photosynthetic profile and the accumulation of macro- and microelements in rice plants (Oryza sativa L.) that received foliar treatments of zinc oxide nanoparticles (ZnO NPs), nitric oxide donor (GSNO), and the association of both (GSNO–ZnO NPs). Zinc concentration in rice husks increased by 66% and 68% in plants treated with ZnO NPs and GSNO–ZnO NPs, respectively. The GSNO treatment caused an increase of 25% in the Fe concentration in the rice grains. Only a small disturbance of the antioxidant system was observed, with increases in H₂O₂, S-NO, and NO₂⁻, mainly in the group treated with GSNO–ZnO NPs; however, the disturbance did not affect the yield, the growth, or vital processes, such as as photosynthetic pigments production. There was an increase in chlorophyll B of 290% and an increase in chlorophyll A of 187% when ZnO NPs was applied. GSNO–ZnO NPs increased chlorophyll B by 345% and chlorophyll A by 345%, indicating that the treatments GSNO, ZnO NPs, and GSNO–ZnO NPs reduced possible oxidative stress and helped as protective treatments.