Synthesis and characterization of TiO2 NPs by aqueous leaf extract of Coleus aromaticus and assess their antibacterial, larvicidal, and anticancer potential

Core-shell composite nanoarchitectonics of TiO2@NiCo2S4 via thermal decomposition approach for photodegradation of congo red

In the present work, TiO2@NiCo2S4 core-shell nanocomposites have been successfully synthesized using a thermal decomposition approach using nickel acetyl acetonate and cobalt acetyl acetonate as metal salts and thiourea as source of sulfur in the presence of TiO2 microspheres in diphenyl ether at about 200 °C in air aiming at their application in photodegradation of congo red (CR), a dye pollutant. The thickness of NiCo2S4 nanoparticles (shell) could be varied using different concentrations of reagents. Various analytical techniques were used to characterize the TiO2@NiCo2S4 core-shell nanocomposites including powder XRD, FE-SEM, XPS, TEM and EDX confirming their successful synthesis. The synthesized core-shell nanocomposites exhibit notable photocatalytic activity towards degradation of an aqueous solution of congo red under sunlight. The photocatalytic degradation efficiency of TiO2@NiCo2S4 nanocomposites is better than that of TiO2-based nanocomposites, metal sulfide nanoparticles and other nanocomposites reported in the literature.

Ag-Ag2O nanocomposite biosynthesis by mixed bacterial cultivation and effect of the ph on size and optical properties of the nanocomposite

This study examines the influence of pH on the energy band gap and crystallite size during the synthesis of a novel Ag-Ag2O nanocomposites through the mixed cultivation of Lactobacillus sp. and Bacillus sp. A range of analytical techniques, including X-ray Diffraction (XRD), UV-visible Spectroscopy (UV-vis), Fourier Transform Infrared Spectroscopy (FTIR), and Transmission Electron Microscopy (TEM), were employed to investigate the structural and optical characteristics of the nanocomposites. XRD analysis confirmed the presence of cubic phases of Ag and Ag2O, with crystallite sizes varying from 8 to 44 nm; notably, smaller crystallites were observed at a pH of 6.5. UV-vis spectroscopy indicated an energy band gap ranging from 1.83 to 1.897 eV, suggesting promising applications for the material. The optimal pH for synthesis, which yielded the smallest particle size as verified by TEM, was identified as 6.5. FTIR analysis revealed the presence of biologically derived coating agents that may enhance the immutability and bioactivity of the nanocomposite. Antibacterial assays demonstrated significant efficacy against Enterococcus faecalis(E. faecalis) and Escherichia coli, particularly highlighting its effectiveness against E. faecalis. Hemolytic assays confirmed the biocompatibility of the nanocomposite at lower concentrations. These findings indicate the potential applications of the biogenic Ag-Ag2O nanocomposites in medical and environmental fields, offering a sustainable solution to challenges associated with bacterial contamination. Future research may focus on integrating these biologically synthesized nanoparticles into advanced materials and coatings to improve their performance.

Review of Antimicrobial Properties of Titanium Dioxide Nanoparticles

There is a growing interest in the utilization of metal oxide nanoparticles as antimicrobial agents. This review will focus on titanium dioxide nanoparticles (TiO2 NPs), which have been demonstrated to exhibit high antimicrobial activity against bacteria and fungi, chemical stability, low toxicity to eukaryotic cells, and therefore high biocompatibility. Despite the extensive research conducted in this field, there is currently no consensus on how to enhance the antimicrobial efficacy of TiO2 NPs. The aim of this review is to evaluate the influence of various factors, including particle size, shape, composition, and synthesis parameters, as well as microbial type, on the antibacterial activity of TiO2 NPs against bacteria and fungi. Furthermore, the review offers a comprehensive overview of the methodologies employed in the synthesis and characterization of TiO2 NPs. The antimicrobial activity of TiO2 exhibits a weak dependence on the microorganism species. A tendency towards increased antibacterial activity is observed with decreasing TiO2 NP size. The dependence on the shape and composition is more pronounced. The most pronounced antimicrobial potential is exhibited by amorphous NPs and NPs doped with inorganic compounds. This review may be of interest to specialists in biology, medicine, chemistry, and other related fields.

Optimizing the green synthesis of antibacterial TiO2 - anatase phase nanoparticles derived from spinach leaf extract

Titanium dioxide nanoparticles, renowned for their abundance, non-toxicity, and stability, have emerged as indispensable components in various fields such as air purification, healthcare, and industrial processes. Their applications as photocatalysts and antibacterial agents are particularly prominent. The synthesis methods significantly influence the properties and subsequent applications of these nanoparticles. While several techniques exist, the biological approach using plant extracts offers advantages such as simplicity, biocompatibility, and cost-effectiveness. This study focused on the green synthesis of titanium dioxide nanoparticles utilizing spinach leaf extract. Within the scope of this investigation, the green synthesis of titanium dioxide nanoparticles through spinach leaf extract were synthesized and optimized, followed by a comprehensive examination of their morphological, structural, and chemical attributes with UV-visible spectroscopy, FTIR spectroscopy, XRD, FESEM, and EDX. The minimum inhibitory concentration (MIC) against E. coli and S. aureus was determined to evaluate their antibacterial potential. Optimal synthesis conditions were identified at 50 °C, using a 1/30 concentration and 20 ml of spinach leaf extract. Spherical anatase nanoparticles, ranging from 10 to 40 nm, were produced under these conditions. The change in the color of the extract, absorption at 247 nm, change and increase of the peak at 800 - 400 wavelengths, and the maximum intensity of X-ray diffraction at the angle of 25.367 with the crystal plane 101 were indications of the synthesis of these nanoparticles. Notably, the synthesized nanoparticles exhibited antibacterial activity with MIC values of 0.5 mg/ml against E. coli and 2 mg/ml against S. aureus. This research presents a novel, eco-friendly approach to synthesizing titanium dioxide nanoparticles with promising antibacterial properties.

Improved anti-diabetic and anticancer activities of green synthesized CuO nanoparticles derived from Tabernaemontana divaricate leaf extract

Copper oxide nanoparticles (CuO NPs) are among the most commonly employed nanoparticle materials owing to their antibacterial qualities, although their primary mechanism of action (MOA) is still not completely understood. CuO NPs are synthesized in this study using leaf extract of Tabernaemontana divaricate (TDCO3), and they are then analyzed using XRD, FT-IR, SEM, and EDX analysis. The zone of inhibition of TDCO3 NPs against both gram-positive (G+) B. subtilis and gram-negative (G-) K. pneumoniae bacteria was 34 mm and 33 mm, respectively. Furthermore, Cu2+/Cu+ ions promote reactive oxygen species and electrostatically bind with the negatively charged teichoic acid in the bacterial cell wall. The anti-inflammatory and anti-diabetics analysis was conducted using standard BSA denaturation and α-amylase inhibition technique with cell inhibition values of 85.66 and 81.18% for TDCO3 NPs. Additionally, the TDCO3 NPs delivered prominent anticancer activity with the lowest IC50 value 18.2 μg/mL in the MTT assay technique against HeLa cancer cells.

Assessment of possible biomedical applications of green synthesized TiO2NPs-an in-vitro approach

Biomedical applications for various types of nanoparticles are emerging on a daily basis. Hence this research was performed to evaluate the antifungal (Aspergillus sp., Alternaria sp., Trichophyton sp., Candida sp., and Penicillium sp.), cytotoxicity (MCF10A cell lines), and antioxidant (DPPH) potential of Coleus aromaticus mediated and pre-characterized TiO2NPs were studied with respective standard methodology. Interestingly, the TiO2NPs exhibited significant antifungal activity on pathogenic fungal strains like Alternaria sp., Aspergillus sp. (31 ± 1.4), Penicillium sp. (31 ± 1.9) Trichophyton sp. (27 ± 2.1), and Candida sp. (26 ± 2.3) at high concentration (250 μg mL-1). However, the considerable levels of zone of inhibitions on fungal pathogens were recorded at 100 μg mL-1 of TiO2NPs as well as it was considerably greater than positive control. It also demonstrated dose based anti-inflammatory and antidiabetic activities. The plant-mediated TiO2NPs demonstrated a maximum DPPH scavenging efficiency of 91% at a dosage of 250 μg mL-1, comparable to the positive control's 94%. Furthermore, TiO2NPs at 100 μg mL-1 concentration did not cause cytotoxicity in MCF10A cell lines. At higher concentrations (250 μg mL-1), the nanoparticles showed the lowest cytotoxicity (17%). These findings suggest that C. aromaticus-mediated TiO2NPs have significant biomedical applications. However, in-vivo studies are needed to learn more about their (C. aromaticus-mediated TiO2NPs) potential biomedical applications.

Carbon Nanomaterials for Biomedical Applications: Progress and Outlook

Recent developments in nanoscale materials have found extensive use in various fields, especially in the biomedical industry. Several substantial obstacles must be overcome, particularly those related to nanostructured materials in biomedicine, before they can be used in therapeutic applications. Significant concerns in biomedicine include biological processes, adaptability, toxic effects, and nano-biointerfacial properties. Biomedical researchers have difficulty choosing suitable materials for drug carriers, cancer treatment, and antiviral uses. Carbon nanomaterials are among the various nanoparticle forms that are continually receiving interest for biomedical applications. They are suitable materials owing to their distinctive physical and chemical properties, such as electrical, high-temperature, mechanical, and optical diversification. An individualized, controlled, dependable, low-carcinogenic, target-specific drug delivery system can diagnose and treat infections in biomedical applications. The variety of carbon materials at the nanoscale is remarkable. Allotropes and other forms of the same element, carbon, are represented in nanoscale dimensions. These show promise for a wide range of applications. Carbon nanostructured materials with exceptional mechanical, electrical, and thermal properties include graphene and carbon nanotubes. They can potentially revolutionize industries, including electronics, energy, and medicine. Ongoing investigation and expansion efforts continue to unlock possibilities for these materials, making them a key player in shaping the future of advanced technology. Carbon nanostructured materials explore the potential positive effects of reducing the greenhouse effect. The current state of nanostructured materials in the biomedical sector is covered in this review, along with their synthesis techniques and potential uses.

Entomotoxic efficacy of fungus-synthesized nanoparticles against immature stages of stored bean pests

Nanopesticides, particularly biosynthesized ones using organic reductants, hold great promise as a cost-effective and eco-friendly alternative to chemical pesticides. However, their efficacy on stored product pests, which can cause damage to dried grains, has not been extensively tested, especially on immature stages. Here, we biosynthesized six types of nanoparticles (NPs) using extracts from the fungus Fusarium solani: silver (AgNPs), selenium (SeNPs), silicon dioxide (SiO₂NPs), copper oxide (CuONPs), titanium dioxide (TiO₂NPs) and zinc oxide (ZnONPs) ranging in size from 8 to 33 nm. To test their efficacy on stored bean pests, they were applied to the eggs and larvae of pest beetles Callosobruchus chinensis and Callosobruchus maculatus (Coleoptera: Chrysomelidae: Bruchinae), which burrow into seeds as larvae. Susceptibility to the NPs was species-dependent and differed between developmental stages; eggs were more susceptible than larvae inhabiting in seeds. SeNPs and TiO₂NPs reduced the hatchability of C. chinensis eggs by 23% and 18% compared to the control, respectively, leading to an 18% reduction in egg-to-adult survival by SeNPs. In C. maculatus, TiO₂NPs applied to eggs reduced larva-to-adult survivorship by 11%, resulting in a 15% reduction in egg-to-adult survival. The egg mass of C. chinensis was 23% smaller than that of C. maculatus: the higher surface-area-to-volume ratio of the C. chinensis eggs could explain their higher acute mortality caused by the NPs compared to C. maculatus eggs. The biosynthesized SeNPs and TiO₂NPs have potential for controlling major stored bean pests when applied to their eggs. This is the first to show the efficacy of biosynthesized SeNPs and TiO₂NPs on stored product pests and the efficacy of Fusarium-synthesized NPs on insects.

Mosquito-Borne Diseases and Their Control Strategies: An Overview Focused on Green Synthesized Plant-Based Metallic Nanoparticles

Mosquitoes act as vectors of pathogens that cause most life-threatening diseases, such as malaria, Dengue, Chikungunya, Yellow fever, Zika, West Nile, Lymphatic filariasis, etc. To reduce the transmission of these mosquito-borne diseases in humans, several chemical, biological, mechanical, and pharmaceutical methods of control are used. However, these different strategies are facing important and timely challenges that include the rapid spread of highly invasive mosquitoes worldwide, the development of resistance in several mosquito species, and the recent outbreaks of novel arthropod-borne viruses (e.g., Dengue, Rift Valley fever, tick-borne encephalitis, West Nile, yellow fever, etc.). Therefore, the development of novel and effective methods of control is urgently needed to manage mosquito vectors. Adapting the principles of nanobiotechnology to mosquito vector control is one of the current approaches. As a single-step, eco-friendly, and biodegradable method that does not require the use of toxic chemicals, the green synthesis of nanoparticles using active toxic agents from plant extracts available since ancient times exhibits antagonistic responses and broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on the different mosquito control strategies in general, and on repellent and mosquitocidal plant-mediated synthesis of nanoparticles in particular, has been reviewed. By doing so, this review may open new doors for research on mosquito-borne diseases.

Characterization and Biological Studies of Synthesized Titanium Dioxide Nanoparticles from Leaf Extract of Juniperus phoenicea (L.) Growing in Taif Region, Saudi Arabia

Green synthesis of metal nanoparticles in nanosized form has acquired great interest in the area of nanomedicine as an environmentally friendly and cost-effective alternative compared to other chemical and physical methods. This study deals with the eco-friendly green synthesis of titanium dioxide nanoparticles (TiO2 NPs) utilizing Juniperus phoenicea leaf extract and their characterization. The biosynthesis of TiO2 NPs was completed in 3 h and confirmed by UV-Vis spectroscopy, a strong band at 205.4 nm distinctly revealed the formation of NPs. Transmissions electron microscopy (TEM) analysis showed the synthesized TiO2 NPs are spherical in shape, with a diameter in a range of 10–30 nm. The XRD major peak at 27.1° congruent with the (110) lattice plane of tetragonal rutile TiO2 phase. Dynamic light scattering (DLS) analysis revealed synthesized TiO2 NPs average particle size (hydrodynamic diameter) of (74.8 ± 0.649) nm. Fourier transmission infrared (FTIR) revealed the bioactive components present in the leaf extract, which act as reducing and capping agents. The antimicrobial efficacy of synthesized TiO2NPs against, Staphylococcus aureus, and Bacillus subtilis (Gram-positive), Escherichia coli and Klebsiella pneumoniae (Gram-negative), Yeast strain (Saccharomyces cerevisiae) and fungi (Aspergillus niger, and Penicillium digitatum) assayed by a disc diffusion method. TiO2NPs inhibited all tested strains by mean inhibition zone (MIZ), which ranged from the lowest 15.7 ± 0.45 mm against K. pneumoniae to the highest 30.3 ± 0.25 against Aspergillus niger. The lowest minimum inhibitory concentration (MIC) and bactericidal (MBC) values were 20 μL/mL and 40 μL/mL of TiO2NPs were observed against Asp. niger. Moreover, it showed significant inhibitory activity against human ovarian adenocarcinoma cells with IC50 = 50.13 ± 1.65 µg/mL. The findings concluded that biosynthesized TiO2 NPs using Juniperus phoenicea leaf extract can be used in medicine as curative agents according to their in vitro antibacterial, antifungal, and cytotoxic activities.

Natural resources for sustainable synthesis of nanomaterials with anticancer applications: A move toward green nanomedicine

Today, researchers have focused on the application of environmentally-benign and sustainable micro- and nanosystems for drug delivery and cancer therapy. Compared to conventional chemotherapeutics, advanced micro- and nanosystems designed by applying abundant, natural, and renewable feedstocks have shown biodegradability, biocompatibility, and low toxicity advantages. However, important aspects of toxicological assessments, clinical translational studies, and suitable functionalization/modification still need to be addressed. Herein, the benefits and challenges of green nanomedicine in cancer nanotherapy and targeted drug delivery are cogitated using nanomaterials designed by exploiting natural and renewable resources. The application of nanomaterials accessed from renewable natural resources, comprising metallic nanomaterials, carbon-based nanomaterials, metal-organic frameworks, natural-derived nanomaterials, etc. for targeted anticancer drug delivery and cancer nanotherapy are deliberated, with emphasis on important limitations/challenges and future perspectives.

Green synthesis of titanium dioxide nanoparticles using plant biomass and their applications- A review

Biosynthesized nanoparticles have sparked a lot of interest as rapidly growing classes of materials for different applications. Plants are considered to be one of the most suitable sources for Green synthesis (GS) as they follow the environment-friendly route of biosynthesis of nanoparticles (NPs). This article focuses on the excavation of Titanium dioxide (TiO₂) NP from different parts of plants belonging to a distinct classification of taxonomic groups. During the process of biological synthesis of titanium NPs from plants, the extract derived from plant sources such as from root, stem, leaves, seeds, flowers, and latex possesses phytocompounds that tend to serve as both capping as well as reducing agents. TiO₂NP is one of the most commonly used engineered nanomaterials in nanotechnology-based consumer products. This article will provide an overview of the GS and characterization of TiO₂NPs from plant extracts of different taxonomic groups. Lastly, this review summarizes the current applications of TiO₂NPs.

Effect of Ethylene Glycol: Citric Acid Molar Ratio and pH on the Morphology, Vibrational, Optical and Electronic Properties of TiO2 and CuO Powders Synthesized by Pechini Method

High-purity TiO₂ and CuO powders were synthesized by the Pechini method, an inexpensive and easy-to-implement procedure to synthetize metal oxides. The variables of synthesis were the ethylene glycol:citric acid molar ratio and the pH. High reproducibility of the anatase and tenorite phase was obtained for all synthesis routes. The degree of purity of the powders was confirmed by XRD, FTIR, UV-Vis absorption and XPS spectra. SEM and TEM images revealed the powders are composed of micrometer grains that can have a spherical shape (only in the TiO₂) or formed by a non-compacted nanocrystalline conglomerate. FTIR spectra only displayed vibrational modes associating TiO₂ and CuO with nanoparticle behavior. UV-Vis absorption spectra revealed the values of maximum absorbance percentage of both systems are reached in the ultraviolet region, with percentages above 83% throughout the entire visible light spectrum for the CuO system, a relevant result for solar cell applications. Finally, XPS experiments allow the observation of the valence bands and the calculation of the energy bands of all oxides.

Silver nanoparticles (AgNPs) fabricating potential of aqueous shoot extract of Aristolochia bracteolata and assessed their antioxidant efficiency

This research was performed to evaluate the silver nanoparticles (AgNPs) fabricating potential of aqueous shoot extract of Aristolochia bracteolata and also assess the free radicals scavenging potential of synthesized AgNPs. The results obtained from this study showed that the aqueous shoot extract of A. bracteolata has the potential to synthesize the AgNPs and it was initially confirmed by color change in the reaction blend as yellow to dark brownish. Subsequently, a clear absorbance peak was found at 425 nm in UV-visible spectrum analysis. The functional groups involved in the capping and stabilization of AgNPs were confirmed by Fourier Transform-Infrared spectroscopy (FTIR) analysis and recorded about 10 sharp peaks 3688, 3401, 2980, 2370, 1948, 1642, 1480, 1280, 782, and 628 cm^-1. The Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) observations revealed that the predominant shape of the AgNPs was spherical and size ranged from 41.43 to 60.51 nm. Interestingly, the green fabricated AgNPs showed significant free radicals scavenging activity and were confirmed with ferric reducing assay, 1, 1-diphenyl-2-picryl-hydrazyl (DPPH), H₂O₂ radicals, and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals scavenging activity. Thus, after a few in-vivo antioxidant studies, Aristolochia bracteolata-mediated AgNPs can be considered as an antioxidant agent.

Efficient double-layer sintering of titanomagnetite concentrate

The traditional titanomagnetite sintering process consumes high fuel and produces weak-strength sinter. In this study, double-layer sintering was used to solve above problems. The theoretical analysis and sintering pot test results showed that sintering of feed bed constituted by two different-basicity layers could improve mineralization and permeability. By using the double layer structure of sintering bed and controlling the basicities of lower and upper layer (2.5 and 1.5, respectively), the yield, productivity, and reduction disintegration index (RDI_+3.15) were 67.32%, 1.65 t m² h⁻¹, 49.68% respectively, which were improved 33.12%, 1.74%, and 9.27%, respectively than those obtained by the traditional sintering process. Meanwhile, 1.69 kg t⁻¹ of solid fuel consumption and nearly 10% of electricity and gas consumption for sintering were saved. It was demonstrated that using different basicities for upper and lower layer of sintering bed would promote formation of silica-ferrite of calcium and aluminum (SFCA) with simultaneous reduction of perovskite, improving the sinter quality.

Green Synthesis of Metal and Metal Oxide Nanoparticles Using Different Plants’ Parts for Antimicrobial Activity and Anticancer Activity: A Review Article

Nanotechnology emerged as a scientific innovation in the 21st century. Metallic nanoparticles (metal or metal oxide nanoparticles) have attained remarkable popularity due to their interesting biological, physical, chemical, magnetic, and optical properties. Metal-based nanoparticles can be prepared by utilizing different biological, physical, and chemical methods. The biological method is preferred as it provides a green, simple, facile, ecofriendly, rapid, and cost-effective route for the green synthesis of nanoparticles. Plants have complex phytochemical constituents such as carbohydrates, amino acids, phenolics, flavonoids, terpenoids, and proteins, which can behave as reducing and stabilizing agents. However, the mechanism of green synthesis by using plants is still highly debatable. In this report, we summarized basic principles or mechanisms of green synthesis especially for metal or metal oxide (i.e., ZnO, Au, Ag, and TiO2, Fe, Fe2O3, Cu, CuO, Co) nanoparticles. Finally, we explored the medical applications of plant-based nanoparticles in terms of antibacterial, antifungal, and anticancer activity.

Antibacterial and Anticancer Potentials of Presynthesized Photosensitive Plectranthus cylindraceus Oil/TiO2/Polyethylene Glycol Polymeric Bionanocomposite

The present study is concerned with the fabrication of the bifunctional Plectranthus cylindraceus oil/TiO2/polyethylene glycol polymeric film for antibacterial and anticancer activities. The suggested film is based on the utility of naturally extracted P. cylindraceus oil in the formation of the polymeric bionanocomposite film decorated with TiO2 nanoparticles. The bionanocomposite film was fabricated by incorporating 15 w% of P. cylindraceus oil with 10 w% polyethylene glycol and 5 w% TiO2 nanoparticles. The active components of P. cylindraceus oil were verified using gas chromatography coupled with mass spectrometry (GC-MS). The surface morphology of the resulted bionanocomposite film was characterized by various spectroscopic and microscopic techniques. The antibacterial potential of the fabricated bionanocomposite film was investigated against four pathogenic strains. The obtained results revealed excellent sensitivity against the bacterial strains, particularly E. coli and S. aureus, with minimum inhibitory concentration 320 µg mL-1 and minimum bactericidal concentration 640 and 1280 µg mL-1 for E. coli and S. aureus, respectively. Polymeric bionanocomposite exerted significant cytotoxicity against human lung carcinoma cell lines in a concentration-dependent manner with an IC50 value of 42.7 ± 0.25 μg mL-1. Safety assessment test against peripheral blood mononuclear cells (PBMCs) demonstrated that the bionanocomposite is nontoxic in nature. Bionanocomposite also showed potent photocatalytic effects. Overall, the results concluded that the bionanocomposite has expressed scope for multifaceted biomedical applications.