Comparison of Metal Nanoparticles as Antifungal Agents: Efficacy, Mechanisms, and Toxicity against <i>Candida, Aspergillus, and Cryptococcus</i>

Nanotechnology is a rapidly developing field of research that studies materials having dimensions of less than 100 nanometers. It is applicable in many areas of life sciences and medicine including skin care and personal hygiene, as these materials are the essential components of various cosmetics and sunscreens. The aim of the present study was to synthesize Zinc oxide (ZnO) and Titanium dioxide (TiO2) nanoparticles (NPs) by using Calotropis procera (C. procera) leaf extract. Green synthesized NPs were characterized by UV spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) to investigate their structure, size, and physical properties. The antibacterial and synergistic effects of ZnO and TiO2 NPs along with antibiotics were also observed against bacterial isolates. The antioxidant activity of synthesized NPs was analyzed by their α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity. In vivo toxic effects of the synthesized NPs were evaluated in albino mice at different doses (100, 200, and 300 mg/kg body weight) of ZnO and TiO2 NPs administered orally for 7, 14, and 21 days. The antibacterial results showed that the zone of inhibition (ZOI) was increased in a concentration-dependent manner. Among the bacterial strains, Staphylococcus aureus showed the highest ZOI, i.e., 17 and 14 mm against ZnO and TiO2 NPs, respectively, while Escherichia coli showed the lowest ZOI, i.e., 12 and 10 mm, respectively. Therefore, ZnO NPs are potent antibacterial agents compared to TiO2 NPs. Both NPs showed synergistic effects with antibiotics (ciprofloxacin and imipenem). Moreover, the DPPH activity showed that ZnO and TiO2 NPs have significantly (p > 0.05) higher antioxidant activity, i.e., 53% and 58.7%, respectively, which indicated that TiO2 has good antioxidant potential compared to ZnO NPs. However, the histological changes after exposure to different doses of ZnO and TiO2 NPs showed toxicity-related changes in the structure of the kidney compared to the control group. The current study provided valuable information about the antibacterial, antioxidant, and toxicity impacts of green synthesized ZnO and TiO2 NPs, which can be influential in the further study of their eco-toxicological effects.

Titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles are important photocatalysts and as such have been extensively studied for the removal of organic compounds from contaminated air and water and for microbial disinfection. Despite much research on the effect of TiO2 and ZnO nanoparticles on different bacterial species, uncertainties remain about which bacteria are more sensitive to these compounds. Very few studies have directly compared the toxicity of ZnO to TiO2 under both light and dark conditions. In addition, authors investigating the photocatalytic inactivation of TiO2 and ZnO nanoparticles on bacteria have failed to investigate the reactive oxygen species (ROS) generation of the nanoparticles, making it difficult to correlate killing action with the generation of ROS. In this study, three types of metal nanoparticle (ZnO < 50 nm, ZnO < 100 nm and TiO2) have been characterised and ROS production assessed through the degradation of methylene blue (MB). The photocatalytic killing potential of three nanoparticle concentrations (0.01, 0.1 and 1 g/L) was then assessed on four representative bacteria: two gram-positive (S. aureus and B. subtilis) and two gram-negative (E. coli and P. aeruginosa). Results showed that out of the three nanoparticles tested, the TiO2 nanoparticles generated more ROS than the ZnO nanoparticles, corresponding to a greater photocatalytic inactivation of three of the four species of bacteria examined. The MB decomposition results correlated well with the bacterial inactivation results with higher TiO2 nanoparticle concentrations leading to greater ROS production and increased loss of cell viability. Although producing less ROS than the TiO2 nanoparticles under ultraviolet light, the ZnO nanoparticles were toxic to two of the bacterial species even under dark conditions. In this study, no correlation between cell wall type and bacterial inactivation was observed for any of the nanoparticles tested although both gram-positive bacteria were sensitive to ROS production. P. aeruginosa cells were resistant to all types of treatment and highlight a potential limitation to the application of these nanoparticles for water treatment.

BackgroundAntioxidants are vital in reducing oxidative stress, a key factor in the pathogenesis of many chronic diseases, including cancer, cardiovascular disease, and neurodegenerative disorders. The aim of our study is to analyze and compare the oxidative potential of biosynthesized selenium, strontium, and zinc oxide nanoparticles (NPs).Materials and methodsSelenium nanoparticles (SeNPs) were synthesized using 20 mM of sodium selenite as the precursor and 1 g each of Cymbopogon citratus and Syzygium aromaticum as reducing and stabilizing agents. Strontium nanoparticles (SrNPs) were synthesized with 30 mM of strontium chloride as the precursor and 1 g of Acacia nilotica as a reducing and stabilizing agent. Zinc oxide nanoparticles (ZnONPs) were synthesized using 30 mM of zinc nitrate as the precursor and 1 g each of Cuminum cyminum and Syzygium aromaticum as reducing and stabilizing agents. Selenium, strontium, and zinc oxide nanoparticles were characterized using Fourier-transform infrared spectroscopy (FT-IR) analysis. The antioxidant activity of biogenically synthesized strontium, selenium and zinc oxide nanoparticles was examined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay (DPPH assay) and hydroxyl radical scavenging assay (H2O2 assay).ResultsThe FT-IR spectra of selenium nanoparticles revealed a peak at 3327.990 cm−1, strontium nanoparticles at 3332.331 cm−1, and zinc oxide nanoparticles at 3216.346 cm−1. The significant results for the green-synthesized selenium, strontium, and zinc oxide nanoparticles were observed in antioxidant assays. The results from the DPPH assay show that at the highest concentration of 50 µL, SrNPs exhibited 90.12 % inhibition, SeNPs displayed 90.12% inhibition, and ZnONPs showed 89.55% inhibition. In the H2O2 assay, at the highest concentration of 50 µL, SrNPs showed 87.43% inhibition, SeNPs displayed 85.11% inhibition, and ZnONPs exhibited 84.66% inhibition. SrNPs demonstrated a higher percentage of inhibition in both the DPPH and H2O2 assays. Maximum inhibitory activity was observed at the highest concentration. However, the prepared nanoparticles showed a slightly lower percentage of inhibition when compared to the standard.ConclusionStrontium nanoparticles synthesized based on Acacia nilotica demonstrated excellent antioxidant activity compared to the synthesized selenium and zinc oxide nanoparticles. Therefore, the study suggests that the produced strontium nanoparticles can serve as an antioxidant agent, owing to their remarkable free radical scavenging activity.

Zinc oxide and selenium nanoparticles can improve semen quality and heat shock protein expression in cryopreserved goat (Capra hircus) spermatozoa

Aim: Zinc oxide (ZnO) and titanium oxide (TiO2) nanoparticles are used on a commercial scale in many countries. Despite numerous studies on the toxicity of nanoparticles, few have addressed their toxicity in edible grains. The aim of this study was to investigate the growth inhibition of ZnO and TiO2 nanoparticles on lentil, wheat, and bean seeds. Methods: The ZnO and TiO2 nanoparticles were investigated using transmission electron microscopy. Different concentrations of ZnO and TiO2 nanoparticles (0.1, 1, 10, 100, and 1000 mg/l) were prepared in distilled water for irrigation of lentil, wheat, and bean seeds. The seeds were irrigated three times a day for 8 consecutive days, with 3 ml of solution per irrigation. To determine the toxicity of nanoparticles, the number of germinated seeds was counted, and the stem lengths were measured using a caliper. Data were analyzed to calculate the 50% lethal concentration (LC50). Results: Exposure to all concentrations of both nanoparticles resulted in growth reduction in lentil seeds. Bean seeds showed decreased growth with ZnO nanoparticles and increased growth with TiO2. Wheat seeds exhibited both growth increases and decreases at nanoparticle concentrations. Conclusions: This study showed that the toxic effect of nanoparticles depends on both the type of nanoparticle and the seeds. Furthermore, the concentration of nanoparticles plays a significant role in their toxicity. Therefore, more research is needed to explore the effects of different nanoparticles on plants in various growth environments to better understand their toxic effects on plant organs and their impact on plant growth and development.

Amelioration of AsV toxicity by concurrent application of ZnO-NPs and Se-NPs is associated with differential regulation of photosynthetic indexes, antioxidant pool and osmolytes content in soybean seedling

Different nanoparticles (NPs) are currently being investigated for their potential role as cryoprotectant during semen cryopreservation in several mammalian species. It may be possible to improve semen quality following cryopreservation by supplementation of NPs in the freezing extenders. The present study was carried out in semen collected from four (4) Assam Hill Goat bucks (10 ejaculates per buck) to investigate the effect of supplementing zinc oxide (ZnO) and selenium (Se) NPs in Tris-citric acid-fructose yolk (TCFY) extender on in vitro sperm quality and in vivo fertility rate after freeze-thawing. The size morphology and zeta potential of ZnO and Se NPs were evaluated prior to its incorporation in the freezing extender. Qualified semen samples (> 70% progressive motility) were divided into five (5) aliquots and then diluted in TCFY extender containing ZnO and Se NP supplementation at different concentrations (T0, control; T1, 0.1mg/mL ZnO NPs; T2, 0.5mg/mL ZnO NPs; T3, 0.5µg/mL Se NPs; and T4, 1µg/mL Se NPs). Diluted semen was packed in 0.25mL straws and then stored in liquid nitrogen. After thawing, post-thaw in vitro sperm attributes were evaluated. Finally, the effect of NPs on in vivo fertility rate was checked in heat-synched does (n = 70) by artificial insemination (AI) using straws that showed superior results during the in vitro study. Results showed that ZnO and Se NPs were poly-crystalline in nature with particle size below 100nm (nm). The evaluated post-thaw sperm in vitro attributes were significantly (p < 0.001) higher in T1 in comparison to T0. The antioxidant enzyme activities were significantly (p < 0.001) higher in T1. Lipid peroxidation (LPO) profile was significantly (p < 0.001) lower in T1. Sperm motility and mitochondrial membrane potential (MMP) had a highly significant (r = 0.580, p < 0.05) association in T1. No significant (p > 0.05) differences in pregnancy rates were recorded after AI in the different treatments. In conclusion, extender supplemented with 0.1mg/mL ZnO NPs improved post-thaw semen quality of goat spermatozoa consequently by increasing activities of endogenous antioxidant enzymes thereby lowering LPO levels. However, improved in vitro outcomes might not correspond to improved field fertility outcomes.

There has been growing concern in recent years about contamination of foods by engineered nanoparticles (NPs) due to their increasing applications in food packaging materials, pesticides, and other products. In this study, we report a systematic approach to detect, characterize, and quantify engineered NPs (i.e., zinc oxide (ZnO) and titanium dioxide (TiO2) NPs) in food products. A series of concentrations of ZnO and TiO2 NPs from 0.05 to 1 wt% were spiked into corn starch, yam starch, and wheat flour. The presence of engineered NPs in foods was detected and measured by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and transmission electron microscopy. The average sizes of ZnO and TiO2 NPs were around 38 and 40 nm in diameter, respectively. Most ZnO NPs were in either spherical or rod-like shape, while most TiO2 NPs were in a spherical shape. The concentrations of engineered NPs in food samples were measured by inductively coupled plasma optical emission spectrometry. Calibration curves were plotted for quantification of NPs in foods (R 2 = 0.984 and 0.995 for ZnO NPs in corn starch and wheat flour, respectively; R 2 = 0.992 and 0.998 for TiO2 NPs in yam starch and wheat flour, respectively). The results of this study could help develop systematic methodologies for detection, characterization, and quantification of NPs in food matrices.

Selenium and zinc are important dietary micronutrients having antimicrobial and antioxidant roles, thereby assisting in normal development, and an enhanced immune system. Supplementation of selenium and zinc for enhancing the growth performance and reproductive capacity in fish was explored in this study. Selenium nanoparticles (SeNPs) and zinc oxide nanoparticles (ZnONPs) were synthesized by high-energy ball milling (HEBM) using a 10-h dry milling technique at a 10:1 ball-to-powder ratio (BPR) and were premixed with basal feed followed by the administration to adult zebra fish (D. rerio) (2 months old) for 30 days. Growth analysis revealed that zebra fish fed with SeNPs + ZnONPs (2 mg/ kg, equimolar mixture) had significantly higher length and weight than only SeNP (2 mg/ kg) or ZnONP (2 mg/ kg) groups and control zebra fish (p < 0.05). The average length–weight relationships were assessed by estimating the condition factor (C), which was highest in the SeNP + ZnONP group (1.96), followed by a downward trend in SeNP (C = 1.15) and ZnONP (1.11) (p < 0.05). Relative gene expression of growth hormone and insulin-like growth factor-1 was significantly high in the SeNP + ZnONP group compared to other groups (p < 0.05), which indicated that combined administration of both the nanoparticles in basal feed enhanced the growth performance of zebra fish. Intracellular ROS generation was low in the combined group, followed by control, SeNP, and ZnONP groups, indicating higher concentrations of both nanoparticles, in particular, ZnONPs induced oxidative stress. Fecundity and the development of fertilized embryos were significantly high in the SeNP + ZnONP–treated zebra fish compared to only the SeNP- or ZnONP-treated group or control (p < 0.05). These findings indicated that supplementation of SeNP + ZnONP in basal feed could considerably improve the growth performance and development of zebra fish which could be exploited for enhancing aquaculture production.

Evaluation and comparison of the effect of incorporating zinc oxide and titanium dioxide nanoparticles on the bond strength and microleakage of two orthodontic fixed retainer adhesives

Exploiting cancer's antioxidative weakness through p53 with nanotoxicology.

Prevention of bacterial growth among root canal treatment sessions is a prerequisite for successful root canal treatment. The most common way to achieve this is to use calcium hydroxide in the treatment sessions. Some studies have shown calcium hydroxide inefficiency in this field. The aim of this study was to investigate and compare the effects of silver, copper, zinc oxide and magnesium oxide nanoparticles on the inhibitory effects of calcium hydroxide based on Enterococcus faecalis species. Enterococcus faecalis bacteria having 0.5 McFarland concentration were prepared. Plates containing BHI agar medium were prepared. In each plate, four wells were created and the plate was cultured using a sterile swab. Afterwards, calcium hydroxide composition of 1% and 2% concentration from silver, copper, zinc oxide and magnesium oxide nanoparticles were prepared separately, as well as the combination of calcium hydroxide with 1% silver in combination with 1% of copper, zinc oxide and magnesium oxide nanoparticles, which were then transferred to the wells. After 24 hours of incubation, the inhibition zone diameter was measured. Data were analyzed by Mann-Withney test. At 1% concentration, only the combination of copper nanoparticles with calcium hydroxide could significantly create an inhibition zone larger than calcium hydroxide alone (P value <0.5). At 2% concentration, the combination of copper nanoparticles with calcium hydroxide, and the combination of silver nanoparticles with calcium hydroxide, were significantly higher than calcium hydroxide alone (P value <0.5). The calcium hydroxide composition containing 1% silver nanoparticles in combination with 1% copper, zinc oxide and magnesium oxide nanoparticles significantly increased the growth inhibition zone more than calcium hydroxide alone. (P Value <0.5). Copper nanoparticles showed the best antibacterial properties among silver, copper, magnesium oxide and zinc oxide nanoparticles in combination with calcium hydroxide. Also, the combination of 1% of nanoparticles with each other increases antibacterial properties.

The aims of this study were to monitor and contrast the diffusion of zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles’ (NPs) penetration and accumulation in human normal endometrium (NE) tissues and uterine leiomyoma (UL) tissues combined with microneedles (MN) in vitro using optical coherence tomography (OCT) and diffuse reflectance (DR) spectral. Continuous OCT and DR spectra monitoring showed that, after application of ZnO or TiO2 NPs, the OCT signal intensities of NE and UL both increase with time, and the TiO2 NPs tend to produce a greater signal enhancement than ZnO NPs in the same type of tissue. And for the same type of NPs, they penetrate faster in NE tissue compared with UL tissue. In addition, the use of MN can significantly enhance the penetration of topically applied ZnO or TiO2 NPs in the tissue. The attenuation coefficients of NE tissue are about 5.01 ± 0.35 mm−1 for ZnO NPs treatment at 195 min and 4.62 ± 0.29 mm−1 for ZnO NPs/MN at 179 min, 4.73 ± 0.30 mm−1 for TiO2 NPs at 183 min, 4.05 ± 0.25 mm−1 for TiO2 NPs/MN at 147 min when the penetration process reached the stable state. And the attenuation coefficients of UL tissue are about 5.0 ± 0.34 mm−1 for ZnO NP treatment at 191 min and 4.20 ± 0.26 mm−1 for ZnO NPs/MN at 169 min, 4.33 ± 0.27 mm−1 for TiO2 NPs at 176 min, 3.53 ± 0.20 mm−1 for TiO2 NPs/MN at 141 min when the penetration process reached the stable state. This suggests that TiO2 NPs penetrate faster and reach the maximum amount of penetration earlier than ZnO NPs with the same condition. The results of attenuation coefficients and reflectance intensity of NE and UL tissue suggests that the accumulation of the TiO2 or ZnO NPs in both NE and UL tissue greatly influenced the tissue optical properties.

The green synthesis of silver (Ag) and zinc oxide (ZnO) nanoparticles (NPs), as well as Ag/Ag2O/ZnO nanocomposites (NCs), using polar and apolar extracts of Chlorella vulgaris, offers a sustainable method for producing nanomaterials with tunable properties. The impact of the synthesis environment and the nanomaterials’ characteristics on cytotoxicity was evaluated by examining reactive species production and their effects on mitochondrial bioenergetic functions. Cytotoxicity assays on PC12 cells, a cell line originated from a rat pheochromocytoma, an adrenal medulla tumor, demonstrated that Ag/Ag2O NPs synthesized with apolar (Ag/Ag2O NPs A) and polar (Ag/Ag2O NPs P) extracts exhibited significant cytotoxic effects, primarily driven by Ag+ ion release and the disruption of mitochondrial function. However, it is more likely the organic content, rather than size, influenced anticancer activity, as commercial Ag NPs, despite smaller crystallite sizes, exhibit less effective activity. ZnO NPs P showed increased reactive oxygen species (ROS) generation, correlated with higher cytotoxicity, while ZnO NPs A produced lower ROS levels, resulting in diminished cytotoxic effects. A comparative analysis revealed significant differences in LD50 values and toxicity profiles. Differentiated PC12 cells showed higher resistance to ZnO, while AgNPs and Ag/Ag2O-based materials had similar effects on both cell types. This study emphasizes the crucial role of the synthesis environment and bioactive compounds from C. vulgaris in modulating nanoparticle surface chemistry, ROS generation, and cytotoxicity. The results provide valuable insights for designing safer and more effective nanomaterials for biomedical applications, especially for targeting tumor-like cells, by exploring the relationships between nanoparticle size, polarity, capping agents, and nanocomposite structures.

This study was conducted on 4-year-old Murcott mandarin (Citrus reticulata L.) treesthat were budded on Volkamer lemon (Citrus volkameriana L.) trees grown in sandy soil at a distance of 3×6 meters under drip irrigation in a private citrus orchard in the Wady El-Mollak region of the Sharkia Governorate, Egypt. The study was conducted over the course of two consecutive seasons, 2020 and 2021. Nine treatments were applied in this experiment as follow:T1-Control (water spray), T2-4% kaolin (Al4Si4O10 (OH) 8), T3-4% potassium silicate (K2SiO3), T4- 4% calcium carbonate (CaCO3), T5-2 cm/l metalusite, T6-1% titanium oxide nano particles (Ti2O3 NPs), T7-4% titanium oxide normal particles (Ti2O3), T8-1% zinc oxide nano particles (ZnO NPs) and T9-4% zinc oxide normal particles (ZnO). The results indicated that all treatments increasedtotal yield pertree (kg) and perfeddan (ton) and fruit weight (g) and also fruits number/tree compared to control treatment.The highest total yield was gained by trees sprayed withMetalusite, titanium oxide, zinc oxide in two forms nano and normal without differences between them in the two seasons.The trees sprayed with Metalusite or titanium oxide nano particles gained leastnumber andpercentagesof sunburned fruits/tree in both seasons, followed by trees sprayed with titanium oxide normal particles.The longest branch was recorded for trees sprayed with potassium silicate, Metalusite, titanium oxide nano and normal particles in the two seasons. The thinner branches were for control trees in the both seasons. The highest number of leaves per branch were gained for trees sprayed with titanium oxide nano particles, while, lowest number of leaves/branch were for trees sprayed with kaolin in the two seasons. The largest leaf area was recorded for trees sprayed by Metalusiteand zinc oxide nano ornormal particlesfollowed by trees sprayed with titanium oxide nano or normal particles, while, the smallest leaf area was forcontrol trees in the two seasons. The uppermost values of leaf fresh and dry weights (g) were for trees sprayed by titanium oxide or zinc oxide in nano or normal particles followed by trees sprayed with Metalusite in the both seasons. All tested trees gave leaves contained higher total chlorophyll insignificant differences between them compared to theuntreatedcontrol in the two seasons.