Characterization of nanomaterials synthesized from Spirulina platensis extract and their potential antifungal activity

Natural Biogenic Templates for Nanomaterial Synthesis: Advances, Applications, and Environmental Perspectives

This review explores the use of biogenic templates in nanomaterial synthesis, emphasizing their role in promoting environmentally sustainable nanotechnology. It categorizes various biogenic templates, including agricultural byproducts and microorganisms, stating their suitability for forming nanostructures due to their distinct properties. A comparative analysis of monostep and multistep synthesis methods is provided, focusing on their efficiencies and outcomes when using biogenic templates. Further, this review also highlights how these templates can generate complex nanostructures and hybrid materials with enhanced functionalities. Applications of biogenic templates across biomedicine, biotechnology, environmental science, and energy are discussed along with their utilization scope in agriculture and electronics. Benefits from nanostructures from biotemplates include sustainability, low cost, and reduced toxicity, but challenges like scalability, reproducibility, and regulatory compliance persist. Future research focuses on improving synthesis techniques, discovering new templates, and evaluating environmental and cytotoxic impacts, especially for biomedical uses. In conclusion, the review reaffirms the potential of biogenic templates in sustainable nanomaterial synthesis while highlighting the ongoing challenges that need to be addressed for broader adoption.

Unlocking the potential of titanium dioxide nanoparticles: an insight into green synthesis, optimizations, characterizations, and multifunctional applications

This comprehensive review explores the emergence of titanium dioxide nanoparticles (TiO2-NPs) as versatile nanomaterials, particularly exploring their biogenic synthesis methods through different biological entities such as plants, bacteria, fungi, viruses, and algae. These biological entities provide eco-friendly, cost-effective, biocompatible, and rapid methods for TiO2-NP synthesis to overcome the disadvantages of traditional approaches. TiO2-NPs have distinctive properties, including high surface area, stability, UV protection, and photocatalytic activity, which enable diverse applications. Through detailed analysis, this review demonstrates significant applications of green fabricated TiO2-NPs in biomedicine, explicitly highlighting their antimicrobial, anticancer, and antioxidant activities, along with applications in targeted drug delivery, photodynamic therapy, and theragnostic cancer treatment. Additionally, the review underscores their pivotal significance in biosensors, bioimaging, and agricultural applications such as nanopesticides and nanofertilizers. Also, this review proves valuable incorporation of TiO2-NPs in the treatment of contaminated soil and water with various environmental contaminants such as dyes, heavy metals, radionuclides, agricultural effluents, and pathogens. These comprehensive findings establish the foundation for future innovations in nanotechnology, underscoring the importance of further investigating bio-based synthetic approaches and bioactivity mechanisms to enhance their efficacy and safety across healthcare, agricultural, and environmental applications.

Cytotoxic Effects of ZnO and Ag Nanoparticles Synthesized in Microalgae Extracts on PC12 Cells

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.

From green chemistry to biomedicine: the sustainable symphony of cobalt oxide nanoparticles

Deciphering the importance of nanostructures in advanced technologies for a broad application spectrum has far-reaching implications for humans and the environment. Cost-effective, abundant cobalt oxide nanoparticles (NPs) are among the most attractive and extensively utilized materials in biomedical sciences due to their high chemical stability, and biocompatibility. However, the methods used to develop the NPs are hazardous for human health and the environment. This article precisely examines diverse green synthesis methods employing plant extracts and microbial sources, shedding light on their mechanism, and eco-friendly attributes with more emphasis on biocompatible properties accompanied by their challenges and avenues for further research. An in-depth analysis of the synthesized cobalt oxide NPs by various characterization techniques reveals their multifaceted functionalities including cytotoxicity, larvicidal, antileishmanial, hemolytic, anticoagulating, thrombolytic, anticancer and drug sensing abilities. This revelatory and visionary article helps researchers to contribute to advancing sustainable practices in nanomaterial synthesis and illustrates the potential of biogenically derived cobalt oxide NPs in fostering green and efficient technologies for biomedical applications.

The effect of plasma activated water on antimicrobial activity of silver nanoparticles biosynthesized by cyanobacterium Alborzia kermanshahica

BACKGROUND

Silver nanoparticles are extensively researched for their antimicrobial properties. Cold atmospheric plasma, containing reactive oxygen and nitrogen species, is increasingly used for disinfecting microbes, wound healing, and cancer treatment. Therefore, this study examined the effect of water activated by dielectric barrier discharge (DBD) plasma and gliding arc discharge plasma on the antimicrobial activity of silver nanoparticles from Alborzia kermanshahica.

METHODS

Silver nanoparticles were synthesized using the boiling method, as well as biomass from Alborzia kermanshahica extract grown in water activated by DBD and GA plasma. The physicochemical properties of the synthesized nanoparticles were evaluated using UV-vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), zeta potential analysis, transmission electron microscopy (TEM), and gas chromatography-mass spectrometry (GC-MS) analysis. Additionally, the disk diffusion method was used to assess the antimicrobial efficacy of the manufactured nanoparticles against both Gram-positive and Gram-negative bacteria.

RESULTS

The spectroscopy results verified the presence of silver nanoparticles, indicating their biosynthesis. The highest amount of absorption (1.049) belonged to the nanoparticles synthesized by boiling under GA plasma conditions. Comparing the FTIR spectra of the plasma-treated samples with DBD and GA revealed that the DBD-treated samples had more intense peaks, indicating that the DBD method proved to be more effective in enhancing the functional groups on the silver nanoparticles. The DLS results revealed that the boiling method synthesized silver nanoparticles under DBD plasma treatment had a smaller particle size (149.89 nm) with a PDI of 0.251 compared to the GA method, and the DBD method produced nanoparticles with a higher zeta potential (27.7 mV) than the GA method, indicating greater stability of the biosynthesized nanoparticles. Moreover, the highest antimicrobial properties against E. coli (14.333 ± 0.47 mm) were found in the DBD-treated nanoparticles. TEM tests confirmed that spherical nanoparticles attacked the E. coli bacterial membrane, causing cell membrane destruction and cell death. The GC-MS results showed that compounds like 2-methylfuran, 3-methylbutanal, 2-methylbutanal, 3-hydroxy-2-butanone, benzaldehyde, 2-phenylethanol, and 3-octen-2-ol were much higher in the samples that were treated with DBD compared to the samples that were treated with GA plasma.

CONCLUSION

The research indicated that DBD plasma was more efficient than GA plasma in boosting the antimicrobial characteristics of nanoparticles. These results might be a cornerstone for future advancements in utilizing cold plasma to create nanoparticles with enhanced antimicrobial properties.

Optimization of Brilliant Blue R photocatalytic degradation by silver nanoparticles synthesized using Chlorella vulgaris

Synthesis of silver nanoparticles (Ag NPs) using microalgae is gaining recognition for its environmentally friendly and cost-effective nature while maintaining high activity of NPs. In the present study, Ag NPs were synthesized using a methanolic extract of Chlorella vulgaris and subjected to calcination. The X-ray diffraction (XRD) analysis showed a crystalline nature of the products with Ag2O and Ag phases with an average crystalline size of 16.07 nm before calcination and an Ag phase with 24.61 nm crystalline size after calcination. Fourier transform infrared spectroscopy (FTIR) revealed the capping functional groups on Ag NPs, while scanning electron microscopy (SEM) displayed their irregular morphology and agglomeration after calcination. The organic coating was examined by energy-dispersive X-ray spectroscopy (EDX) and thermogravimetric (TGA) analyses, confirming the involvement of the metabolites. The UV-Vis analysis showed a difference in optical properties due to calcination. Synthesized Ag NPs were applied for the photodegradation of hazardous dye Brilliant Blue R in visible light. Different values of light intensity, catalyst dose, initial dye concentration, and pH were tested to identify the optimal set of operating conditions. The highest degradation efficiency of 90.6% with an apparent rate constant of 0.04402 min-1 was achieved after 90 min of irradiation in the highest tested catalyst dosage.

Novel nanoconjugates of metal oxides and natural red pigment from the endophyte Monascus ruber using solid-state fermentation

BACKGROUND

Antimicrobial resistance has emerged as a major global health threat, necessitating the urgent development of new antimicrobials through innovative methods to combat the rising prevalence of resistant microbes. With this view, we developed three novel nanoconjugates using microbial natural pigment for effective application against certain pathogenic microbes.

RESULTS

A natural red pigment (RP) extracted from the endophyte Monascus ruber and gamma rays were applied to synthesize RP-ZnO, RP-CuO, and RP-MgO nanoconjugates. The synthesized nanoconjugates were characterized by different techniques to study their properties. The antimicrobial potential of these nanoconjugates was evaluated. Moreover, the antibiofilm, protein leakage, growth curve, and UV light irradiation effect of the synthesized nanoconjugates were also studied. Our results confirmed the nano-size, shape, and stability of the prepared conjugates. RP-ZnO, RP-CuO, and RP-MgO nanoconjugates showed broad antimicrobial potential against the tested bacterial and fungal pathogens. Furthermore, the RP-ZnO nanoconjugate possessed the highest activity, followed by the RP-CuO against the tested microbes. The highest % inhibition of biofilm formation by the RP-ZnO nanoconjugate. Membrane leakage of E. coli and S. aureus by RP-ZnO nanoconjugate was more effective than RP-MgO and RP-CuO nanoconjugates. Finally, UV light irradiation intensified the antibiotic action of the three nanoconjugates and RP-ZnO potential was greater than that of the RP-MgO, and RP-CuO nanoconjugates.

CONCLUSION

These findings pave the way for exploiting the synthesized nanoconjugates as potential materials in biomedical applications, promoting natural, green, and eco-friendly approaches.

Harnessing the power of Neobacillus niacini AUMC-B524 for silver oxide nanoparticle synthesis: optimization, characterization, and bioactivity exploration

BACKGROUND

Biotechnology provides a cost-effective way to produce nanomaterials such as silver oxide nanoparticles (Ag2ONPs), which have emerged as versatile entities with diverse applications. This study investigated the ability of endophytic bacteria to biosynthesize Ag2ONPs.

RESULTS

A novel endophytic bacterial strain, Neobacillus niacini AUMC-B524, was isolated from Lycium shawii Roem. & Schult leaves and used to synthesize Ag2ONPS extracellularly. Plackett-Burman design and response surface approach was carried out to optimize the biosynthesis of Ag2ONPs (Bio-Ag2ONPs). Comprehensive characterization techniques, including UV-vis spectral analysis, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, dynamic light scattering analysis, Raman microscopy, and energy dispersive X-ray analysis, confirmed the precise composition of the Ag2ONPS. Bio-Ag2ONPs were effective against multidrug-resistant wound pathogens, with minimum inhibitory concentrations (1-25 µg mL-1). Notably, Bio-Ag2ONPs demonstrated no cytotoxic effects on human skin fibroblasts (HSF) in vitro, while effectively suppressing the proliferation of human epidermoid skin carcinoma (A-431) cells, inducing apoptosis and modulating the key apoptotic genes including Bcl-2 associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), Caspase-3 (Cas-3), and guardian of the genome (P53).

CONCLUSIONS

These findings highlight the therapeutic potential of Bio-Ag2ONPs synthesized by endophytic N. niacini AUMC-B524, underscoring their antibacterial efficacy, anticancer activity, and biocompatibility, paving the way for novel therapeutic strategies.

Ecofriendly fabrication of cobalt nanoparticles using Azadirachta indica (neem) for effective inhibition of Candida-like fungal infection in medicated nano-coated textile

This study involves the formulation of cobalt nanoparticles by means of ethanolic Azadirachta indica (neem) extract (CoNP@N). Later, the formulated buildup was incorporated into cotton fabric in order to mitigate antifungal infection. Optimization of the formulation was carried out by considering the effect of plant concentration, temperature, and revolutions per minute (rpm) used, through design of the experiment (DOE), response surface methodology (RSM), and ANOVA of the synthetic procedure. Hence, graph was potted with the aid of effecting parameters and the related factors (size of particle and zeta potential). Further characterization of nanoparticles was performed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Attenuated total reflection-Fourier transform infrared (ATR-FTIR) was considered for the detection of functional groups. The structural property of CoNP@N was calculated with the aid of powder X-ray diffraction (PXRD). The surface property was measured with the use of a surface area analyzer (SAA). The values of Inhibition concentration (IC50) and zone of inhibition (ZOI), were calculated, so as to determine the antifungal property against both the strains (Candida albicans, MTCC 227and Aspergillus niger, MTCC 8652). The further nano-coated cloth was subjected to a durability test, and hence the cloth was washed (through the purpose of time 0; 10; 25; and 50 washing cycles), and then its anti-fungal operation to a couple of strains was retained. Primarily, 51 μg/ml of cobalt nanoparticles incorporated on the cloth was retained but after 50 washing cycles in 500 ml of purified water, the cloth showed more efficiency contrary to C. albicans than towards A. niger.

Aflatoxins in Peanut (Arachis hypogaea): Prevalence, Global Health Concern, and Management from an Innovative Nanotechnology Approach: A Mechanistic Repertoire and Future Direction

Arachis hypogaea is the most significant oilseed nutritious legume crop in agricultural trade across the world. It is recognized as a valued crop for its contributions to nourishing food, as a cooking oil, and for meeting the protein needs of people who are unable to afford animal protein. Currently, its production, marketability, and consumption are hindered because of Aspergillus species infection that consequently contaminates the kernels with aflatoxins. Regarding health concerns, humans and animals are affected by acute and chronic aflatoxin toxicity and millions of people are at high risk of chronic levels. Most methods used to store peanuts are traditional and serve effectively for short-term storage. Now the question for long-term storage has been raised, and this promptly finds potential approaches to the issue. It is imperative to reduce the aflatoxin levels in peanuts to a permissible level by introducing detoxifying innovations. Most of the detoxification reports mention physical, chemical, and biological techniques. However, many current approaches are impractical because of time consumption, loss of nutritional quality, or weak detoxifying efficiency. Therefore, it is crucial to investigate practical, economical, and green methods to control Aspergillus flavus that address current global food security problems. Herein, a green and economically revolutionary way is a nanotechnology that has demonstrated its potential to connect farmers to markets, elevate international marketability, improve human and animal health conditions, and enhance food quality and safety by the management of fungal diseases. Due to the antimicrobial potential of nanoparticles, they act as nanofungicides and have an incredible role in the control of aflatoxins. Nanoparticles have ultrasmall sizes and therefore penetrate the fungal body and invade the pathogen machinery, leading to fungal cell death by ROS production, mutation in DNA, disruption of organelles, and membrane leakage. This is the first mechanistic overview that unveils a comprehensive insight into aflatoxin contamination in peanuts, its prevalence, health effects, and management in addition to nanotechnological interventions that serve as a triple defense approach to detoxify aflatoxins. The optimum use of nanofungicides ensures food safety and the development of goals, especially "zero hunger".

Bifunctional folic acid targeted biopolymer Ag@NMOF nanocomposite [{Zn2 (1,4-bdc) 2 (DABCO)} n] as a novel theranostic agent for molecular imaging of colon cancer by SERS

Without a doubt, cancer and its negative impact on human health have created many hurdles for people across the world since conventional approaches have not offered a reliable ability in the eradication of cancer. As a result, finding novel approaches, like using bimodal nanoparticles as a potential nanocarrier in molecular imaging and cancer therapy, is remarkably required these days. In the present study, ex-situ (Ge) and in-situ (Gi) green synthesized silver (Ag) nanoparticles entrapped in metal-organic framework nanocomposites (NMOF) coated with folic acid (FA) targeted chitosan (CS) was successfully developed as a novel bifunctional nanocarrier for detection and treatment of colon cancer cells. Then nanocarriers, such as NMOF-CS-FA, Ge-Ag@NMOF-CS-FA, Gi-Ag@NMOF-CS-FA, and C-Ag@NMOF-CS-FA, were characterized via FT-IR, DLS, SERS, TEM, and SEM and results have potentially confirmed the quality and quantity of synthesized nanocomposites. The hydrodynamic diameters of NMOF-CS, Ge-Ag@NMOF-CS, Gi-Ag@NMOF-CS, and C-Ag@NMOF-CS specimens were measured at around 99.7 ± 10 nm, 110 ± 10 nm, 118 ± 10 nm, 115 ± 10 nm, respectively. Also, the PDI values less than 0.2 confirm the reliable distribution of these nanocomposites. Afterward, the cell viability assay was conducted on HCT116 and HGF cell lines for evaluating biocompatibility and targeting efficiency of nanocomposites; FA functionalized nanocomposites have intensively indicated better performance in cancer cells targeting and their inhibition, and IC50 was attained for 10 ng/mL of Ge-Ag@NMOF-CS-FA while non-targeted nanocarriers did not have toxicity more than 20 % on HCT116 colon cancer cells. Moreover, according to the results, the cell viability of HGF normal cells was at least 85 % after being exposed to different concentrations of nanocomposites for 24 h. This indicates that the synthesized nanocomposites do not have significant toxic effects on normal cells. The results indicate that this novel nanocomposite has the potential to effectively deliver drugs to cancer cells.

Functionalization of niobium nitrogen-doped titanium dioxide (TiO2) nanoparticles with ethanolic extracts of Mentha arvensis

Titanium dioxide (TiO2) nanoparticles have gained significant attention due to their wide-ranging applications. This research explores an approach to functionalize Niobium Nitrogen Titanium Dioxide nanoparticles (Nb-N-TiO2 NPs) with Mentha arvensis ethanolic leaf extracts. This functionalization allows doped NPs to interact with the bioactive compounds in extracts, synergizing their antioxidant activity. While previous studies have investigated the antioxidant properties of TiO2 NPs synthesized using ethanolic extracts of Mentha arvensis, limited research has focused on evaluating the antioxidant potential of doped nanoparticles functionalized with plant extracts. The characterization analyses are employed by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Ultraviolet-visible (UV-Vis) spectroscopy to evaluate these functionalized doped nanoparticles thoroughly. Subsequently, the antioxidant capabilities through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays have been assessed. Within functionalized Nb-N-TiO2, the FTIR has a distinctive peak at 2350, 2010, 1312, 1212, and 1010 cm-1 with decreased transmittance associated with vibrations linked to the Nb-N bond. SEM revealed a triangular aggregation pattern, 500 nm to 2 µm of functionalized Nb-N-TiO2 NPs. Functionalized doped Nb-N-TiO2 NPs at 500 µg mL-1 exhibited particularly robust antioxidant activity, achieving an impressive 79% efficacy at DPPH assessment; meanwhile, ferric reduction efficiency of functionalized doped Nb-N-TiO2 showed maximum 72.16%. In conclusion, doped Nb-N-TiO2 NPs exhibit significantly enhanced antioxidant properties when functionalized with Mentha arvensis ethanolic extract compared to pure Nb-N-TiO2 manifested that doped Nb-N-TiO2 have broad promising endeavors for various biomedicine applications.

Microalgae as a potential natural source for the green synthesis of nanoparticles

The increasing global population is driving the development of alternative sources of food and energy, as well as better or new alternatives for health and environmental care, which represent key challenges in the field of biotechnology. Microalgae represent a very important source material to produce several high-value-added bioproducts. Due to the rapid changes in the modern world, there is a need to build new materials for use, including those in the nanometer size, although these developments may be chronological but often do not occur at a time. In the last few years, a new frontier has opened up at the interface of biotechnology and nanotechnology. This new frontier could help microalgae-based nanomaterials to possess new functions and abilities. Processes for the green synthesis of nanomaterials are being investigated, and the availability of biological resources such as microalgae is continuously being examined. The present review provides a concise overview of the recent advances in the synthesis, characterization, and applications of nanoparticles formed using a wide range of microalgae-based biosynthesis processes. Highlighting their innovative and sustainable potential in current research, our study contributes towards the in-depth understanding and provides latest updates on the alternatives offered by microalgae in the synthesis of nanomaterials.

Synthesis of nanoparticles using Trichoderma Harzianum, characterization, antifungal activity and impact on Plant Growth promoting Bacteria

Globally cultivated cereals are frequently threatened by various plant pathogenic agents such as Fusarium fungi. To combat these pathogens, researchers have made nanoparticles as potential agricultural pesticides. In this study, selenium and titanium dioxide NPs were synthesized using Trichoderma harzianum metabolites. Characterization of the NPs indicated varying size and shapes of both NPs and functional groups existence to constitute both NPs. The evaluation of antifungal activity of NPs against plant pathogenic fungi, Fusarium culmorum, indicated both NPs maximum antifungal activity at concentration of 100 mg/L. The impacts of nanoparticles on some beneficial plant growth promoting bacteria (PGPB) were evaluated and showed their inhibition effect on optical density of PGPB at a concentration of 100 mg/L but they did not have any impact on nitrogen fixation by bacteria. Existence of TiO2NPs reduced the intensity of color change to pink compared to the control indicating auxin production. Both NPs demonstrated different impact on phosphate solubilization index. This study suggests that the synthesized nanoparticles have the potential to serve as antifungal compounds at special concentration against plant diseases without significantly reducing the potential of PGPB at low concentrations.

Green Synthesis of Narrow-Size Silver Nanoparticles Using Ginkgo biloba Leaves: Condition Optimization, Characterization, and Antibacterial and Cytotoxic Activities

Natural products derived from medicinal plants offer convenience and therapeutic potential and have inspired the development of antimicrobial agents. Thus, it is worth exploring the combination of nanotechnology and natural products. In this study, silver nanoparticles (AgNPs) were synthesized from the leaf extract of Ginkgo biloba (Gb), having abundant flavonoid compounds. The reaction conditions and the colloidal stability were assessed using ultraviolet-visible spectroscopy. X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy (FTIR) were used to characterize the AgNPs. AgNPs exhibited a spherical morphology, uniform dispersion, and diameter ranging from ~8 to 9 nm. The FTIR data indicated that phytoconstituents, such as polyphenols, flavonoids, and terpenoids, could potentially serve as reducing and capping agents. The antibacterial activity of the synthesized AgNPs was assessed using broth dilution and agar well diffusion assays. The results demonstrate antibacterial effects against both Gram-positive and Gram-negative strains at low AgNP concentrations. The cytotoxicity of AgNPs was examined in vitro using the CCK-8 method, which showed that low concentrations of AgNPs are noncytotoxic to normal cells and promote cell growth. In conclusion, an environmentally friendly approach for synthesizing AgNPs from Gb leaves yielded antibacterial AgNPs with minimal toxicity, holding promise for future applications in the field of biomedicine.

Green Synthesis, Characterization, and Antiparasitic Effects of Gold Nanoparticles against Echinococcus granulosus Protoscoleces

Echinococcosis, or hydatidosis, is one of the most important zoonotic diseases, which is initiated by the larval stage in the clasts of Echinococcus granulosus. For the treatment of hydatidosis, surgery is still the preferred method and the first line of treatment for symptomatic patients. Unfortunately, most of the scolicidal agents that are injected inside cysts during hydatid cyst surgery have side effects, including leaking out of the cyst and adverse effects on the living tissue of the host, such as necrosis of liver cells, which limits their use. This work was carried out to study the lethal effect of green synthesized gold nanoparticles (Au-NCs) against hydatid cyst protoscoleces. Au-NCs were green synthesized using the Saturja khuzestanica extract. Au-NCs were characterized by UV-visible absorbance assay, electron microscopy analysis, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Scolicidal properties of Au-NCs (1-5 mg/mL) were studied against protoscoleces for 10-60 min. The effect of Au-NCs on the expression level of the caspase-3 gene as well as the ultrastructural examination was studied by real-time PCR and scanning electron microscopy (SEM). The cytotoxicity of Au-NCs on hepatocellular carcinoma (HepG₂) and normal embryonic kidney (HEK293) cell lines was also studied by the cell viability assay. The obtained Au-NCs are cubes and have an average size of 20-30 nm. The highest scolicidal efficacy was observed at 5 mg/mL with 100% mortality after 20 min of treatment for hydatid cyst protoscoleces. In ex vivo, Au-NCs required more incubation time, indicating more protoscolicidal effects. Au-NCs markedly upregulated the gene level of caspase-3 in protoscoleces; whereas they changed the ultra-structure of protoscoleces by weakening and disintegrating the cell wall, wrinkles, and protrusions due to the formation of blebs. We showed the effective in vitro and ex vivo scolicidal effects of Au-NCs against hydatid cyst protoscoleces by provoking the apoptosis process of caspase-3 activation and changing the ultrastructure of protoscoleces with no significant cytotoxicity against human normal cells. However, additional studies should be conducted to determine the possible harmful side effects and accurate efficacy.

Nanoparticles from Microalgae and Their Biomedical Applications

Over the years, microalgae have been a source of useful compounds mainly used as food and dietary supplements. Recently, microalgae have been used as a source of metabolites that can participate in the synthesis of several nanoparticles through inexpensive and environmentally friendly routes alternative to chemical synthesis. Notably, the occurrence of global health threats focused attention on the microalgae application in the medicinal field. In this review, we report the influence of secondary metabolites from marine and freshwater microalgae and cyanobacteria on the synthesis of nanoparticles that were applied as therapeutics. In addition, the use of isolated compounds on the surface of nanoparticles to combat diseases has also been addressed. Although studies have proven the beneficial effect of high-value bioproducts on microalgae and their potential in medicine, there is still room for understanding their exact role in the human body and translating lab-based research into clinical trials.

Enhanced Wound Healing Potential of Spirulina platensis Nanophytosomes: Metabolomic Profiling, Molecular Networking, and Modulation of HMGB-1 in an Excisional Wound Rat Model

Excisional wounds are considered one of the most common physical injuries. This study aims to test the effect of a nanophytosomal formulation loaded with a dried hydroalcoholic extract of S. platensis on promoting excisional wound healing. The Spirulina platensis nanophytosomal formulation (SPNP) containing 100 mg PC and 50 mg CH exhibited optimum physicochemical characteristics regarding particle size (598.40 ± 9.68 nm), zeta potential (−19.8 ± 0.49 mV), entrapment efficiency (62.76 ± 1.75%), and Q6h (74.00 ± 1.90%). It was selected to prepare an HPMC gel (SPNP-gel). Through metabolomic profiling of the algal extract, thirteen compounds were identified. Molecular docking of the identified compounds on the active site of the HMGB-1 protein revealed that 12,13-DiHome had the highest docking score of −7.130 kcal/mol. SPNP-gel showed higher wound closure potential and enhanced histopathological alterations as compared to standard (MEBO® ointment) and S. platensis gel in wounded Sprague-Dawley rats. Collectively, NPS promoted the wound healing process by enhancing the autophagy process (LC3B/Beclin-1) and the NRF-2/HO-1antioxidant pathway and halting the inflammatory (TNF-, NF-κB, TlR-4 and VEGF), apoptotic processes (AIF, Caspase-3), and the downregulation of HGMB-1 protein expression. The present study’s findings suggest that the topical application of SPNP-gel possesses a potential therapeutic effect in excisional wound healing, chiefly by downregulating HGMB-1 protein expression.

Operando monitoring of a room temperature nanocomposite methanol sensor

The sensing of volatile organic compounds by composites containing metal oxide semiconductors is typically explained via adsorption-desorption and surface electrochemical reactions changing the sensor's resistance. The analysis of molecular processes on chemiresistive gas sensors is often based on indirect evidence, whereas in situ or operando studies monitoring the gas/surface interactions enable a direct insight. Here we report a cross-disciplinary approach employing spectroscopy of working sensors to investigate room temperature methanol detection, contrasting well-characterized nanocomposite (TiO2@rGO-NC) and reduced-graphene oxide (rGO) sensors. Methanol interactions with the sensors were examined by (quasi) operando-DRIFTS and in situ-ATR-FTIR spectroscopy, the first paralleled by simultaneous measurements of resistance. The sensing mechanism was also studied by mass spectroscopy (MS), revealing the surface electrochemical reactions. The operando and in situ spectroscopy techniques demonstrated that the sensing mechanism on the nanocomposite relies on the combined effect of methanol reversible physisorption and irreversible chemisorption, sensor modification over time, and electron/O2 depletion-restoration due to a surface electrochemical reaction forming CO2 and H2O.

Influence of the Alcohols on the ZnO Synthesis and Its Properties: The Photocatalytic and Antimicrobial Activities

Zinc oxide (ZnO) nanomaterials are used in various health-related applications, from antimicrobial textiles to wound dressing composites and from sunscreens to antimicrobial packaging. Purity, surface defects, size, and morphology of the nanoparticles are the main factors that influence the antimicrobial properties. In this study, we are comparing the properties of the ZnO nanoparticles obtained by solvolysis using a series of alcohols: primary from methanol to 1-hexanol, secondary (2-propanol and 2-butanol), and tertiary (tert-butanol). While the synthesis of ZnO nanoparticles is successfully accomplished in all primary alcohols, the use of secondary or tertiary alcohols does not lead to ZnO as final product, underlining the importance of the used solvent. The shape of the obtained nanoparticles depends on the alcohol used, from quasi-spherical to rods, and consequently, different properties are reported, including photocatalytic and antimicrobial activities. In the photocatalytic study, the ZnO obtained in 1-butanol exhibited the best performance against methylene blue (MB) dye solution, attaining a degradation efficiency of 98.24%. The comparative study among a series of usual model dyes revealed that triarylmethane dyes are less susceptible to photo-degradation. The obtained ZnO nanoparticles present a strong antimicrobial activity on a broad range of microorganisms (bacterial and fungal strains), the size and shape being the important factors. This permits further tailoring for use in medical applications.

Comparative Study of Antimicrobial Activity of Silver, Gold, and Silver/Gold Bimetallic Nanoparticles Synthesized by Green Approach

Nanotechnology is one of the most recent technologies. It is uncertain whether the production of small-size nanoparticles (NPs) can be achieved through a simple, straightforward, and medicinally active phytochemical route. The present study aimed to develop an easy and justifiable method for the synthesis of Ag, Au, and their Ag/Au bimetallic NPs (BNPs) by using Hippeastrum hybridum (HH) extract, and then to investigate the effects of Ag, Au, and their Ag/Au BNPs as antimicrobial and phytotoxic agents. Ag, Au, and their Ag/Au BNPs were characterized by UV-visible spectroscopy, FT-IR spectroscopy, XRD, EDX, and SEM analysis. XRD analysis conferring to the face of face-centered cubic crystal structure with an average size of 13.3, 10.72, and 8.34 nm of Ag, Au, and Ag/Au BNPs, respectively. SEM showed that Ag, Au, and Ag/Au BNPs had spherical morphologies, with calculated nano measurements of 40, 30, and 20 nm, respectively. The EDX analysis confirmed the composition of elemental Ag signal of the HH-AgNPs with 22.75%, Au signal of the HH-AuNPs with 48.08%, Ag signal with 12%, and Au signal with 38.26% of the Ag/Au BNPs. The Ag/Au BNPs showed an excellent antimicrobial efficacy against Gram-positive Staphylococcus aureus, Actinomycetes meriye, Bacillus cereus, Streptococcus pyogenes, Methicillin-resistant Staphylococcus aureus, Micrococcus luteus, Streptococcus pneumonia, and Gram-negative Klebsiella pneumonia, Escherichia coli, and Serratia marcescens bacterial strains, as well as against three fungal strains (Aspergillus niger, Aspergillus fumigatus, and Aspergillus flavus) compared to HH extract, HH-AgNPs, and HH-AuNPs. However, further investigations are recommended to be able to minimize potential risks of application.