Jacek Wojnarowicz

In microwave solvothermal synthesis (MSS), ZnO particle size increases with precursor water content. This study tested whether that dependence changes when metallic silver forms in the same step. ZnO/Ag nanocomposites with nominally 2 mol% Ag were obtained by single-step MSS from zinc and silver acetates in ethylene glycol, without a separately added reducing agent, at measured precursor water contents of 1.47–3.97 wt%. XRD detected wurtzite ZnO and metallic Ag⁰ but no crystalline silver oxides. As the water content increased, the apparent ZnO crystallite size grew monotonically from 15 to 25 nm in the a–b basal plane and from 18 to 40 nm along the c axis. The BET specific surface area fell from 50.7 to 29.0 m²/g and the equivalent diameter d_(BET) rose from 22 to 38 nm. Standardless EDS gave similar area-averaged Ag estimates for all samples, and AsB imaging of one sample revealed high-Z features consistent with an Ag-rich phase. An Ag-free ZnO reference series synthesised in the same reactor under identical conditions showed a similar dependence on water content. For three pairs of samples with nearly matched water contents, the series differed in specific surface area and d_(BET) by at most about 7%, much less than the changes with water content. The separate preparation of the two series and the lack of replicate syntheses limit the ability to attribute the observed differences unambiguously to the presence of silver. Antimicrobial and photocatalytic activity was not investigated.

Zinc oxide nanoparticles (ZnO NPs) exhibit antifungal properties and may be applied for limitation of pathogen growth in crop production. The objectives of the study were: 1) to investigate and compare the effects of ZnO submicron particles (ZnO SMPs) and ZnO nanoparticles (ZnO NPs) on the in vitro response of Botrytis cinerea , Fusarium oxysporum, and Alternaria alternata and 2) to evaluate the impact of those particles on suppressing disease symptoms caused by the three plant pathogens on potted tomato plants ( Solanum lycopersicum L. ‘Bawole Serce’). In the in vitro experiment ZnO SMPs or ZnO NPs at the concentration of 0, 100, 200, 500, 1000, and 2000 mg/l were applied. In the in vivo experiment, potted tomato plants were infected with pathogens and sprayed with ZnO SMPs or ZnO NPs suspensions at the concentration of 500 mg/l. Experimental objects included also non-infected control plants, as well as infected and ZnO SMPs/NPs non-treated control plants. The addition of ZnO NPs and ZnO SMPs to the PDA medium significantly inhibited the growth of mycelium of all tested pathogens. However, the advantage of ZnO NPs over ZnO SMPs in inhibiting the growth of mycelium has not been demonstrated. Interestingly, the lowest tested ZnO SMPs/NPs concentration (100 mg/l) caused a significant reduction of mycelium growth of F. oxysporum and A. alternata (up to 33.32%). As for B. cinerea , only the concentration of 500 mg/l and higher concentrations of tested material samples limited the growth of its mycelium (up to 82.67%). In vivo experiment on tomato plants did not confirm the effectiveness of ZnO SMPs in the reduction of B. cinerea and A. alternata infection, in contrast to ZnO NPs, which significantly limited the growth of all pathogens (by between 56.99% and 65.11%).

Purpose: Studying the role of nanoparticles in plant cryopreservation is essential for developing innovative methods to conserve plant genetic resources amid environmental challenges. This research investigated the effects of gold (AuNPs), silver (AgNPs), and zinc oxide (ZnONPs) nanoparticles on the structural integrity, genetic stability, and metabolic activity of cryopreserved plant materials with medicinal properties. Methods: Shoot tips from two bleeding heart (Lamprocapnos spectabilis (L). Fukuhara) cultivars, ‘Gold Heart’ and ‘Valentine’, were cryopreserved using the encapsulation-vitrification technique, with nanoparticles added at concentrations of 5 or 15 ppm during either the preculture phase or the alginate bead matrix formation. Post-recovery, the plants underwent histological, molecular, and biochemical analyses. Results: Electron microscopy observations of LN-derived plant material confirmed the production of micro-morpho-structurally stable cells. It was found that nanoparticles could penetrate the cell and accumulate in its various compartments, including the nucleus. As for the genetic analysis, SCoT markers identified polymorphisms in 11.5% of ‘Gold Heart’ plants, while RAPDs detected mutations in 1.9% of ‘Valentine’ specimens. Analysis of Molecular Variance (AMOVA) indicated that in the ‘Valentine’ cultivar, all genetic variation detected was within populations and not significantly affected by nanoparticle treatments. In ‘Gold Heart’, the majority (94%) of genetic variation detected was within populations, while 6% was attributed to nanoparticle treatments (mostly the application of 15 ppm ZnONPs). The application of nanoparticles significantly influenced the metabolic profile of bleeding heart plants, particularly affecting the synthesis of phenolic acids and aldehydes, as well as the antioxidant mechanisms in both ‘Gold Heart’ and ‘Valentine’ cultivars. The content of proteins was altered in ‘Gold Heart’ plants but not in ‘Valentine’. Conclusion: The results suggest that different types and concentrations of NPs have varying effects on the production of specific metabolites, which could be harnessed to modulate plant secondary metabolism for desired pharmacological outcomes.

The integration of nanoparticles into plant cryopreservation protocols holds great promise for improving the survival rates and recovery potential of explants. This study aimed to verify the effect of nanoparticles on the ex-vitro performance of cryopreservation-derived plants. Lamprocapnos spectabilis (L.) Fukuhara (bleeding heart) ’Gold Heart’ and ’Valentine’ cultivars were used as the plant material. The encapsulation-vitrification cryopreservation protocol of shoot tips included the preculture, encapsulation, dehydration, storage in liquid nitrogen, rewarming, and recovery steps. Gold (AuNPs), silver (AgNPs), or zinc oxide (ZnONPs) nanoparticles were added at varying concentrations, either into the preculture medium or the protective bead matrix during encapsulation. After the in vitro recovery, the plants were transferred to the glasshouse and subjected to detailed biometrical, biochemical and cytogenetic analyses. Nanoparticles had no evident effect on the acclimatization efficiency (80–100% survival) and leaf number in L. spectabilis ‘Gold Heart’. Nonetheless, shoots developed from alginate beads supplemented with 5 ppm AuNPs were twice as long as the control, while the leaves of plants grown on the preculture medium with ZnONPs contained significantly more chlorophyll and had higher Leaf Soil-Plant Analysis Development (SPAD) values. Moreover, several NPs treatments stimulated the development of leaves, including their surface area, length, and perimeter. Higher ZnONPs levels enhanced also the replication process, resulting in higher nuclear DNA content. As for L. spectabilis ‘Valentine’, alginate augmentation with 5 ppm AgNPs or 5 ppm ZnONPs stimulated the elongation of shoots. There was also a tendency suggesting a positive influence of 5 ppm AgNPs in the alginate bead matrix on foliar growth. The effect of nanoparticles on the content of flavonoids, anthocyanins, and stress markers in the plants varied depending on the treatment and cultivar, but also on the organ studied (leaf or stem). Overall, L. spectabilis ‘Gold Heart’ was more stress-tolerant and genetically stable than ‘Valentine’ judging by the activity of Photosystem II (PSII) and flow cytometric analyses, respectively. The complex effects of nanoparticles on survival, biometric parameters, physiological responses, and cytogenetic events underscore the intricate interplay between nanoparticles and plant systems. Nonetheless, our research confirmed the positive effect of nanoparticles on the ex-vitro growth and development of L. spectabilis plants after cryostorage.

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.

Critical-size bone defects necessitate bone void fillers that should be integrated well and be easily vascularized. One viable option is to use a biocompatible synthetic polymer and sonocoat it with zinc oxide (ZnO) nanoparticles (NPs). However, the ideal NP concentration and size must be assessed because a high dose of ZnO NPs may be toxic. Electrospun PDLLA/PLGA scaffolds were produced with different concentrations (0.5 or 1.0 s of sonocoating) and sizes of ZnO NPs (25 nm and 70 nm). They were characterized by SEM, EDX, ICP-OES, and the water contact angle. Vascularization and integration into the surrounding tissue were assessed with the CAM assay in the living chicken embryo. SEM, EDX, and ICP-OES confirmed the presence of ZnO NPs on polymer fibers. Sonocoated ZnO NPs lowered the WCA compared with the control. Smaller NPs were more pro-angiogenic exhibiting a higher vessel density than the larger NPs. At a lower concentration, less but larger vessels were visible in an environment with a lower cell density. Hence, the favored combination of smaller ZnO NPs at a lower concentration sonocoated on PDLLA/PLGA electrospun meshes leads to an advanced state of tissue integration and vascularization, providing a valuable synthetic bone graft to be used in clinics in the future.

This article describes benefits of the application of zinc oxide submicron particles (ZnO SMPs), zinc oxide nanoparticles (ZnO NPs) and ZnO NPs combined with silver NPs (ZnO + Ag NPs) in chrysanthemum micropropagation. Single node explants of Chrysanthemum × morifolium (Ramat.) Hemsl. ‘UTP Burgundy Gold (UBG)’ and ‘UTP Pinky Gold (UPG)’ were inoculated on the Murashige and Skoog (MS) medium and treated with 100 mg · L ⁻¹ , 200 mg · L ⁻¹ , or 400 mg · L ⁻¹ ZnO SMPs, ZnO NPs (1.5% H ₂ O), ZnO NPs (6% H ₂ O), ZnO + 0.1% Ag NPs (1.5% H ₂ O), ZnO + 0.1% Ag NPs (6% H ₂ O), ZnO + 1% Ag NPs (1.5% H ₂ O) and ZnO + 1% Ag NPs (6% H ₂ O). Generally, the tested materials stimulated the growth and development of plantlets. In ‘UBG’, the most prominent treatments affecting increases in the number of leaves, micropropagation coefficient, shoot length and shoot FW/DW weight included 400 mg · L ⁻¹ ZnO SMPs and 100 mg · L ⁻¹ ZnO NPs (6% H ₂ O). In ‘UPG’, the treatments with 200 mg · L ⁻¹ ZnO + 0.1% Ag NPs (6% H ₂ O) and 200 mg · L ⁻¹ ZnO + 1% Ag NPs (6% H ₂ O) were the most successful. The latter treatment stimulated an intensive development of root systems in the two studied cultivars. High values of leaf area, perimeter and width were reported in both cultivars for 400 mg · L ⁻¹ ZnO + 1% Ag NPs (6% H ₂ O). As compared to the control, the treated plants were characterised by a similar or, most often, lower content of chlorophylls and carotenoids. The randomly amplified polymorphic DNA (RAPD) and start codon targeted polymorphism (SCoT) marker system analyses of the 400 mg · L ⁻¹ ZnO SMPs/ZnO NPs/ZnO + Ag NPs-treated chrysanthemums confirmed their genetic fidelity with the control plants. The obtained results can be implemented in the commercial large-scale production of chrysanthemums.

Nanotechnology creates opportunities to improve the micropropagation of horticultural plants. The aim of this study was to test the effects of zinc oxide submicron particles (ZnO SMPs), and nanoparticles (NPs) such as ZnO NPs, and ZnO+Ag NPs, at the concentrations of 100, 200, or 400 mg·L −1 ,...

Synthetic calcium phosphates, e.g., hydroxyapatite (HAP) and tricalcium phosphate (TCP), are the most commonly used bone-graft materials due to their high chemical similarity to the natural hydroxyapatite—the inorganic component of bones. Calcium in the form of a free ion or bound complexes plays a key role in many biological functions, including bone regeneration. This paper explores the possibility of increasing the Ca²⁺-ion release from HAP nanoparticles (NPs) by reducing their size. Hydroxyapatite nanoparticles were obtained through microwave hydrothermal synthesis. Particles with a specific surface area ranging from 51 m²/g to 240 m²/g and with sizes of 39, 29, 19, 11, 10, and 9 nm were used in the experiment. The structure of the nanomaterial was also studied by means of helium pycnometry, X-ray diffraction (XRD), and transmission-electron microscopy (TEM). The calcium-ion release into phosphate-buffered saline (PBS) was studied. The highest release of Ca²⁺ ions, i.e., 18 mg/L, was observed in HAP with a specific surface area 240 m²/g and an average nanoparticle size of 9 nm. A significant increase in Ca²⁺-ion release was also observed with specific surface areas of 183 m²/g and above, and with nanoparticle sizes of 11 nm and below. No substantial size dependence was observed for the larger particle sizes.

Studies on nanoparticles’ effects on plants are relevant for horticulture. This study aimed to test the influence of zinc oxide submicron particles (ZnO SMPs), zinc oxide nanoparticles (ZnO NPs), and zinc oxide nanoparticles combined with silver nanoparticles (ZnO+1%Ag NPs) applied at 100 and 500 mg·L⁻¹ on the regeneration and biochemical activity of adventitious shoots in Chrysanthemum × morifolium (Ramat.) Hemsl. ‘UTP Burgundy Gold’ and ‘UTP Pinky Gold’. The original microwave solvothermal synthesis and characteristics of the ZnO samples were described. Internodes were cultured on the MS medium with 0.6 mg∙L⁻¹ 6-benzylaminopurine (BAP) and 2 mg∙L⁻¹ indole-3-acetic acid (IAA). In ‘UTP Burgundy Gold’, the highest shoot regeneration efficiency was obtained for 100 mg·L⁻¹ ZnO SMPs and 500 mg·L⁻¹ ZnO NPs treatments (6.50 and 10.33 shoots per explant, respectively). These shoots had high or moderate chlorophyll and carotenoid contents. In ‘UTP Pinky Gold’, the highest shoot number was produced in the control (12.92), for 500 mg·L⁻¹ ZnO SMPs (12.08) and 500 mg·L⁻¹ ZnO NPs (10.42). These shoots had increased chlorophyll (a+b)-to-carotenoid ratios. In ‘UTP Pinky Gold’, the ZnO SMPs and ZnO NPs affected the anthocyanins biosynthesis, whereas ZnO + 1%Ag NPs decreased the phenolics accumulation. These results are important for the improvement of chrysanthemum micropropagation.