A comprehensive review on green synthesis of titanium dioxide nanoparticles and their diverse biomedical applications

Metal oxide nanoparticles (NPs) have found a variety of applications in numerous industrial, medical, and environmental fields s, attributable to recent advances in the nanotechnology field. Titanium dioxide nanoparticles (TiO2-NPs) have gained importance as metal oxide NPs due to their potential in various fields, particularly nanomedicine and other biomedicine fields. Several studies have confirmed that NPs produced via the biosynthesis route using natural resources have significant advantages such as fewer toxic contaminants, less subsequent complex chemical synthesis, environmental friendliness, cost-effectiveness, and stability when compared to NPs produced by conventional methods, and its production with controlled shapes and sizes. Therefore, considerable effort is being expended to implement biological synthesis methods with these proven advantages. TiO2-NPs can be made using a variety of biological, chemical, and physical methods. Physicochemical methods are costly, emit high levels of toxic chemicals into the atmosphere, and consume a lot of energy. On the other hand, the biological approach is an environmentally safe, cost-effective, dependable, convenient, and easy way to synthesize TiO2-NPs. In this review, the bio-mediated synthesis, as well as various biomedical applications of TiO2-NPs, were discussed.

Applications of Metal and Metal Oxide-Based Nanomaterials in Medical and Biological Activities

Nanomaterials have been attracting the attention of many researchers because of their size, high stability, affinity, and selectivity nature. Over the past decades, considerable intensive studies on many metal and metal-oxide nanomaterials have drawn consideration through their significant properties like size, shape, surface mass proportion, and their reactivity; all these properties are fundamental cornerstones for the turn of events and use of nanomaterials and nanoscale gadgets in biomedical areas. There is also a vast scope for a broad range of biofunctional applications such as antibacterial, antiviral, antifungal, antitumor, bioimaging, tissue engineering, biosensors, gene, and drug delivery. The authors review the nature, forms, and synthesis of nanomaterials here, with a thorough biological synthesis assessment. They also address the development of nanoparticles by microorganisms in depth, and this chapter also includes updates on different biological and biomedical applications of these bionanomaterials.

Biological Synthesis of Green Nanoparticles through a Variety of Sources and Their Applications

Nanotechnology is a creating part of drug sciences wherein the particles reach out in nanosizes and end up being more responsive when appeared differently in relation to their novel partners. Nanoparticle synthesis utilizing microorganisms and plants by green synthesis innovation is naturally protected, cost-effective, and environment-friendly. This development is especially repaying similarly as diminishing the noxious quality brought about by the ordinarily coordinated Nanoparticles. The compelling conveyance of medications and tissue designing using nanotechnology displayed fundamental commitments in translational examination identified with the drug items and their applications. Nanotechnology related to science leads to a high level space of nanobiotechnology that includes living substances of both prokaryotic and eukaryotic beginning like algae, cyanobacteria, actinomycetes, bacteria, viruses, yeasts, fungi, and plants. This review makes a brief introduction of environment friendly Nanoparticles and their implementations.

Biological Synthesis of Silver Nanoparticles and their Biomedical Activity: A Review

: Nanotechnology studies the various phenomena of physio-chemical procedures and biological properties for the generation of nanosized particles, and their rising challenges in the various sectors, like medicine, engineering, agriculture, electronic, and environmental studies. The nanosized particles exhibit good anti-microbial, anti-inflammatory, cytotoxic, drug delivery, anti-parasitic, anti-coagulant and catalytic properties because of their unique dimensions with large surface area, chemical stability and higher binding density for the accumulation of various bio-constituents on their surfaces. Biological approaches for the synthesis of silver nanoparticles (AgNPs) have been reviewed because it is an easy and single-step protocol and a viable substitute for the synthetic chemical-based procedures. Physical and chemical approaches for the production of AgNPs are also mentioned herein. Biological synthesis has drawn attention because it is cost-effective, faster, non-pathogenic, environment-friendly, easy to scale-up for large-scale synthesis, and having no demand for usage of high pressure, energy, temperature, or noxious chemical ingredients, and safe for human therapeutic use. Therefore, the collaboration of nanomaterials with bio-green approaches could extend the utilization of biological and cytological properties compatible with AgNPs. In this perspective, there is an immediate need to develop ecofriendly and biocompatible techniques, which strengthen efficacy against microbes and minimize toxicity for human cells. The present study introduces the biological synthesis of silver nanoparticles, and their potential biomedical applications have also been reviewed.

The use of plant fibers for oligosaccharide production with libraries constructed by combinatorial enzyme technology

: Combinatorial chemistry involves the chemical or biological synthesis of libraries of the diverse structural population of a template molecule and the screening for the variants expressing desirable target properties. The approach has been a focus of research activity in modern drug discovery and biotechnology for accelerating the discovery and development of novel therapeutic and bioactive compounds. This review describes the application of combinatorial chemistry in enzyme technology as a novel technique and invention developed in our laboratory to construct oligosaccharide libraries in the conversion of plant fibers. The theory, mechanism, development, and application of this combinatorial enzyme approach are presented for the first time. The potential food and non-food uses of oligosaccharides are described. Citrus pectin and wheat insoluble fiber have been used as substrates for combinatorial enzyme reactions. Generation of libraries of structural variants of pectic oligosaccharides (oligoGalA) and feruloyl oligosaccharides (FOS) demonstrates the feasibility and usefulness of the technique in the transformation of plant biomass to value-added products.

Boosted Electronic, NLO and Absorption Characteristics for Quercetin and Taxifolin; Comparative Experimental and DFT Studies

In the present study, a considerable, reproducible, and eco-friendly biological synthesis of Ag nanoparticles using Mangifera indica leaf extract as a reductant is documented. The spectroscopic characteristics of synthesized Ag nanoparticles are described by both UV-Vis and FT-IR techniques. The bandgap offsets, reactivity, and NLO properties for two flavonoids, quercetin, and taxifolin, are examined using the DFT approach. Also, a detailed comparative analysis for HOMO-LUMO interactions among quercetin and taxifolin is discussed. Results show that quercetin and taxifolin possess dipole moment (DM=4.79, 3.99 Debye) and bandgap offset (2.59, 2.98 eV). Both molecules are promising candidates as window layers for solar cells and memory switch devices. In addition, hyperpolarizability calculations show that quercetin NLO response is higher than taxifolin, which sets a revolutionary recall for NLO manufacture upgrade. Moreover, NBO and UV-Vis absorption characteristics are reported as well.

Biological Synthesis of Nanocatalysts and Their Applications

Over the past few decades, the synthesis and potential applications of nanocatalysts have received great attention from the scientific community. Many well-established methods are extensively utilized for the synthesis of nanocatalysts. However, most conventional physical and chemical methods have some drawbacks, such as the toxicity of precursor materials, the requirement of high-temperature environments, and the high cost of synthesis, which ultimately hinder their fruitful applications in various fields. Bioinspired synthesis is eco-friendly, cost-effective, and requires a low energy/temperature ambient. Various microorganisms such as bacteria, fungi, and algae are used as nano-factories and can provide a novel method for the synthesis of different types of nanocatalysts. The synthesized nanocatalysts can be further utilized in various applications such as the removal of heavy metals, treatment of industrial effluents, fabrication of materials with unique properties, biomedical, and biosensors. This review focuses on the biogenic synthesis of nanocatalysts from various green sources that have been adopted in the past two decades, and their potential applications in different areas. This review is expected to provide a valuable guideline for the biogenic synthesis of nanocatalysts and their concomitant applications in various fields.

Biogenic Synthesis of Iron Oxide Nanoparticles Using Enterococcus faecalis: Adsorption of Hexavalent Chromium from Aqueous Solution and In Vitro Cytotoxicity Analysis

The biological synthesis of nanoparticles is emerging as a potential method for nanoparticle synthesis due to its non-toxicity and simplicity. In the present study, a bacterium resistant to heavy metals was isolated from a metal-contaminated site and we aimed to report the synthesis of Fe3O4 nanoparticles via co-precipitation using bacterial exopolysaccharides (EPS) derived from Enterococcus faecalis_RMSN6 strains. A three-variable Box–Behnken design was used for determining the optimal conditions of the Fe3O4 NPs synthesis process. The synthesized Fe3O4 NPs were thoroughly characterized through multiple analytical techniques such as XRD, UV-Visible spectroscopy, FTIR spectroscopy and finally SEM analysis to understand the surface morphology. Fe3O4 NPs were then probed for the Cr(VI) ion adsorption studies. The important parameters such as optimization of initial concentration of Cr(VI) ions, effects of contact time, pH of the solution and contact time on quantity of Cr(VI) adsorbed were studied in detail. The maximum adsorption capacity of the nanoparticles was found to be 98.03 mg/g. The nanoparticles could retain up to 73% of their efficiency of chromium removal for up to 5 cycles. Additionally, prepared Fe3O4 NPs in the concentration were subjected to cytotoxicity studies using an MTT assay. The investigations using Fe3O4 NPs displayed a substantial dose-dependent effect on the A594 cells. The research elucidates that the Fe3O4 NPs synthesized from EPS of E. faecalis_RMSN6 can be used for the removal of heavy metal contaminants from wastewater.