Shivendu Ranjan

In this paper, we report an enzyme dependent, green one-pot deoxygenation cum decoration method to synthesize diastase-conjugated reduced graphene oxide (DRG) nanosheets, DRG/gold nanoparticles (DRG/Au) composite. The DRG synthesis was completed in 7 h under heating at 90 °C on water bath. Selected area electron diffraction (SAED) and Atomic force microscopy (AFM) study has revealed the formation of bilayered reduced graphene oxide sheets. Transmission electron microscopy (TEM) images of DRG/Au composite have shown the uniform decoration of gold nanoparticles (AuNPs) onto the DRG nanosheet surface. Fourier transform infrared spectroscopy (FTIR) and Raman results additionally have shown the functionalization of enzyme molecules onto the DRG nanosheet surface after reduction making it as an effective platform towards the efficient binding of gold nanoparticles. In vitro cytotoxicity studies by MTT assay on A549 and HCT116 cell lines exhibited that the cytotoxicity of the prepared graphene oxide (GO), DRG and DRG/Au is dose dependant. These results have shown that this synthetic method is effective for the production of large scale graphene in a low cost, simple and green method. Since this process avoids the use of hazardous and toxic substances, the produced DRG/Au composites are likely to offer various potential applications in biology and medicine.

Different sized tetragonal tin oxide nanoparticles (SnO 2 NPs) were synthesized using Piper nigrum seed extract at three different calcination temperatures (300, 500, 900 °C) and these nanoparticles (NPs) were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infrared spectrophotometry (FT-IR). The optical properties were studied using UV–Vis and photoluminescence (PL) spectrophotometers. The generation of reactive oxygen species (ROS) was monitored by using a fluorescence spectrophotometer and fluorescence microscope. The cytotoxicity of the synthesized SnO 2 NPs was checked against the colorectal (HCT116) and lung (A549) cancer cell lines and the study results show that SnO 2 NPs were toxic against cancer cell lines depending on their size and dose. IC 50 values of SnO 2 NPs having average particle sizes of 8.85 ± 3.5, 12.76 ± 3.9 and 29.29 ± 10.9 nm are 165, 174 and 208 μg L −1 against HCT116, while these values are 135, 157 and 187 μg L −1 against A549 carcinoma cell lines, respectively. The generated ROS were responsible for the cytotoxicity of SnO 2 NPs to the studied cancer cells and smaller size NPs generated more ROS and hence showed higher cytotoxicity over larger size NPs. The results of this study suggest that the synthesized stable nanoparticles could be a potent therapeutic agent towards cancerous cell lines.

Nano-titania is widely used in the food industry due to its efficient antimicrobial activity. However, the mechanism of microbial toxicity of nano-titania is poorly known. Here, nano-TiO2 has been fabricated by microwave-irradiation chemistry, a new method, and then tested for antimicrobial activity. Mutagenicity of nano-TiO2 was evaluated using Salmonella typhimurium histidine-auxotrophic strains. The reactive oxygen generation test was performed using 2,7-dichlorofluorescein diacetate dye. To test membrane permeabilization, E. coli cultures were grown in nutrient broth at an optical density of 0.3–0.5 at 610 nm, harvested by centrifugation at 11,000g for 10 min, washed and resuspended in 0.5 % NaCl solution. We also analyzed superoxide formation and membrane integrity, and we used scanning electron microscopy. Results show that nano-TiO2 has a minimum inhibitory concentration of 15 µg/mL, and a minimum bactericidal concentration of 20 µg/mL for E. coli. The bacterial inner wall was ruptured, and cytoplasmic content was released after 5 min of treatment in a dose-dependent manner. Notably, superoxide formation was not observed, which establishes the fact that reactive oxygen generation and alteration of membrane integrity, as well as permeability, is the major mechanism of antimicrobial activity of nano-TiO2.

Silica nanoparticles were synthesized through a versatile sol–gel combustion method from hydrazide based hypercoordinated silicon complexes derived from the reaction of silicon tetrachloride with O-silylated hydrazide derivatives. The complexes were characterized by 1 H, 13 C, 29 Si NMR and ESI-mass spectrometric techniques. A refined morphology was observed in the product after sintering i.e. from spherical to rod shaped nanoparticles. The powder X-ray diffraction patterns and the TEM images of silica show the formation of silica nanoparticles. The IR spectra show Si–O linkages and DLS studies indicate the particle size distribution to be between 20 and 100 nm for the material before sintering and 70–120 nm after sintering at 1000 C. A TEM image of the decomposed gel indicates the formation of crystalline silica rods. This work also demonstrates the influence of nano-sized silica particles on antibacterial activity (DIZ, MIC and MBC) i.e. better activity was shown for nano-rods derived from the hypercoordinated silicon complexes than the conventional TEOS (sol–gel) method. Experiments on the generation of reactive oxygen species (ROS) through oxidative stress demonstrate the toxicity of nanosilica particles.

The use of nanoparticles in food or pharma requires a molecular-level perceptive of how NPs interact with protein corona once exposed to a physiological environment. In this study, the conformational changes of bovine serum albumin (BSA) were investigated in detail when exposed to different concentration of titanium dioxide nanoparticle by various techniques. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin and titanium dioxide nanoparticles at different concentrations were investigated. The interaction, BSA conformations, kinetics, and adsorption were analyzed by dynamic light scattering, Fourier transform infrared spectroscopy and fluorescence quenching. Dynamic light scattering analysis confirms the interaction with major changes in the size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.1 molecules of serum albumin to titanium dioxide nanoparticles. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20 min. The spectroscopic analysis suggests that there is a conformational change both at secondary and tertiary structure levels. A distortion in both α-helix and β-sheets was observed by Fourier transform infrared (FTIR) spectroscopy. Fluorescence quenching analysis confirms the interaction of a molecule of bovine serum albumin to the single TiO2 nanoparticle. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20 min. The data of the present study determines the detailed evaluation of BSA adsorption on TiO2 nanoparticle along with mechanism and adsorption kinetics.

Blanching is the most widely used processing techniques that increases the shelf life of fruits, vegetables and canned food. It softens the fruits and vegetables, aids in peeling and is vital to the canning process. This review elucidates the pros and cons of blanching – both wet and dry – on food products, with a special reference to bell peppers. Agricultural products with high nutritional value and substantial market demand need to be preserved to retain freshness and nutritional qualities till it reaches the processing industry or the consumer. In this review, we described the various attributes of the wet and dry blanching processes with the aim of providing a guide for the reader to design a blanching technique that may maximize the retention of nutrients, micronutrients and volatiles while minimizing the retention of enzymes that cause degradation of fruits and vegetables.
Practical Applications

This study shows that microwave blanching of food products is far better approach than other blanching methods as it causes minimal/lesser damage unlike IR blanching and wet blanching methods. This can be said based on the fact that microwave blanching does not involve water as required in the process of wet blanching and, thus, reduces the chances of microbial contamination. The results found in this study can be applied in the development of an optimized blanching approach as to minimize the retention of enzymes that causes degradation and to maximize the retention of nutrients, micronutrients and volatiles.

As the nanoparticles (NPs) enter into the biological interface, they have to encounter immediate and first exposure to many proteins of different concentrations. The physicochemical interaction of NPs and proteins is greatly influenced not only by the number and type of proteins; but also the surface chemistry of NPs. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin (BSA) and silver nanoparticles (AgNPs) at different concentrations were investigated. The interaction, BSA conformations, kinetics and adsorption were analyzed by UV–Visible spectrophotometer, dynamic light scattering (DLS), FT-IR spectroscopy and fluorescence quenching. DLS, FTIR and UV–visible spectrophotometric analysis confirms the interaction with minor alterations in size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.5 molecules of BSA to AgNP. Further, pseudo-second order kinetics was determined with equilibrium contact-time of 30 min. The data of the present study determines the detailed evaluation of BSA adsorption on AgNP along with mechanism, kinetics and isotherm of the adsorption.

Nanotechnology has seen exponential growth in last decade due to its unique physicochemical properties; however, the risk associated with this emerging technology has withdrawn ample attention in the past decade. Nanotoxicity is majorly contributed to the small size and large surface area of nanomaterials, which allow easy dispersion and invasion of anatomical barriers in human body. Unique physio-chemical properties of NPs make the investigation of their toxic consequences intricate and challenging. This makes it important to have an in-depth knowledge of different mechanisms involved in nanomaterials's action as well as toxicity. Nano-toxicity has various effects on human health and diseases as they can easily enter into the humans via different routes, mainly respiratory, dermal and gastrointestinalroutes. This also limits the use of nanomaterials as therapeutic and diagnostic tools. This review focuses on the nanomaterial-cell interactions leading to toxicological responses. Different mechanisms involved in nanoparticle-mediated toxicity with the main focus on oxidative stress, genotoxic and carcinogenic potential has also been discussed. Different methods and techniques used for the characterization of nanomaterials in food and other biological matrices have also been discussed in detail. Nano-toxicity on different organs - with the major focus on the cardiac and respiratory system – have been discussed. Conclusively, the risk management of nanotoxicity is also summarized. This review provides a better understanding of the current scenario of the nanotoxicology, disease progression due to nanomaterials, and their use in the food industry and medical therapeutics. Briefly, the required rules, regulations and the need of policy makers has been discussed critically.

Titanium dioxide nanoparticles (TNPs) are widely used in the pharmaceutical and cosmetics industries. It is used for protection against UV exposure due to its light-scattering properties and high refractive index. Though TNPs are increasingly used, the synthesis of TNPs is tedious and time consuming; therefore, in the present study, microwave-assisted hybrid chemical approach was used for TNP synthesis. In the present study, we demonstrated that TNPs can be synthesized only in 2.5 h; however, the commonly used chemical approach using muffle furnace takes 5 h. The activity of TNP depends on the synthetic protocol; therefore, the present study also determined the effect of microwave-assisted hybrid chemical approach synthetic protocol on microbial and cytotoxicity. The results showed that TNP has the best antibacterial activity in decreasing order from Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The IC50 values of TNP for HCT116 and A549 were found to be 6.43 and 6.04 ppm, respectively. Cell death was also confirmed from trypan blue exclusion assay and membrane integrity loss was observed. Therefore, the study determines that the microwave-assisted hybrid chemical approach is time-saving; hence, this technique can be upgraded from lab scale to industrial scale via pilot plant scale. Moreover, it is necessary to find the mechanism of action at the molecular level to establish the reason for greater bacterial and cytotoxicological toxicity.

Titanium dioxide nanoparticles are widely used in consumer products, paints and pharmaceutical preparations. They have been shown to induce cytotoxicity, genotoxicity and carcinogenicity—in vitro and in vivo. So far there is lack of standardized protocol for in silico analysis of nano-toxicological evaluations. In the present study, it was attempted to analyze the titanium dioxide nanoparticles-protein interaction through docking using AutoDock 4.0.5 software. Titanium dioxide nanoparticles with particle size of 1.09 nm were docked with different cellular proteins. Binding site area and volume has been determined by using CastP online server and docking has been performed at the active site as a pocket. The docked structures were analyzed for the most efficient binding with amino acids. It is the first study to report the interaction of titanium dioxide nanoparticles without any surface modification with proteins using docking analysis. The negative binding and docking energy inferred that the interaction of titanium dioxide nanoparticles with certain proteins is significant. Titanium dioxide nanoparticle shows significant interaction with intercellular adhesion molecule-1, P38 mitogen-activated protein kinases (P-38), placental growth factor and nuclear factor kappa-light-chain-enhancer of activated B cell proteins. Further, it has been observed that titanium dioxide nanoparticles show frequent interaction with proline, lysine as well as leusine.

The present study was carried out to fabricate the food grade vitamin E acetate nanoemulsion using edible mustard oil and to evaluate its improved bioactivities. A food-grade vitamin E acetate nanoemulsion was fabricated using the edible mustard oil and surfactant Tween-80. Flocculation was not observed for 15 days. The nanoemulsion was characterized for droplet morphology and size distribution using atomic force microscope and zetasizer, respectively. We observe a stable nanoemulsion of spherical morphology and a size distribution of 86.45 ± 3.61 nm. Further, the high-performance liquid chromatography method was used to determine the vitamin E acetate concentration and encapsulation efficiency for the stable nanoemulsion. These nanoemulsions showed improved bioactivity, antioxidant, and antimicrobial activity and could be potentially used to increase the shelf life of fruit juice.

In recent years, silver nanoparticles (AgNPs) have attracted considerable interest in the field of food, agriculture and pharmaceuticals mainly due to its antibacterial activity. AgNPs have also been reported to possess toxic behavior. The toxicological behavior of nanomaterials largely depends on its size and shape which ultimately depend on synthetic protocol. A systematic and detailed analysis for size variation of AgNP by thermal co-reduction approach and its efficacy toward microbial and cellular toxicological behavior is presented here. With the focus to explore the size-dependent toxicological variation, two different-sized NPs have been synthesized, i.e., 60 nm (Ag60) and 85 nm (Ag85). A detailed microbial toxicological evaluation has been performed by analyzing minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), diameter of inhibition zone (DIZ), growth kinetics (GrK), and death kinetics (DeK). Comparative cytotoxicological behavior was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. It has been concluded by this study that the size of AgNPs can be varied, by varying the concentration of reactants and temperature called as “thermal co-reduction” approach, which is one of the suitable approaches to meet the same. Also, the smaller AgNP has shown more microbial and cellular toxicity.

Diastase, a natural enzyme, was used for the one pot aqueous synthesis of gold nanoparticles (AuNPs) of tunable size. During the synthetic process, diastase acts concurrently as both a reducing and stabilizing agent, while no additional chemical reagents or surfactants are added. The formation of AuNPs was confirmed by using a UV-visible spectrophotometer, with a characteristic surface plasmon resonance (SPR) band at 530 nm. The size of the diastase-stabilized AuNPs can be easily controlled by changing the quantity of diastase. The produced AuNPs were characterized by using powder X-ray diffraction (XRD), UV-visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The FTIR spectrum revealed the capping of diastase on the surface of AuNPs. Furthermore, the formed gold nanoparticles are stable for more than three months. In vitro cytotoxicity studies by MTT assay on HCT116 and A549 cancer cells showed that the cytotoxicity of the as-synthesized Au nanocolloids depends on their size and dose.

Application of nanotechnology in the agro-food sector is one of the fastest growing fields in nano-research. The increase in number of the publications, patents and intellectual property rights in the field of nano-agri-food and recent research trends in food processing, packaging, nutraceutical delivery, quality control and functional food is by itself an evidence of the above statement. Government organizations, scientists, inventors as well as industries are coming up with new techniques, protocols and products that have a direct application of nanotechnology in agriculture and food products.

This review provides a detailed overview of the application of nanotechnology in the field of agriculture, and food science & technology. Additionally, a brief idea about the classification of nanomaterials, synthesis and characterization techniques is discussed. Some exciting thoughts are also discussed on nanotechnological applications in agricultural practices including nano-agri for enhanced productivity, agricultural water quality management (WQM), product processing, storage and quality control with nano-sensors. The risk assessment and safety concerns with respect to nano agro-food research have also been highlighted.

Tissue engineering is very fast growing scientific area in this era which is used to create, repair, and/or replace cells, tissues and organs by using cell and/or combinations of cells with biomaterials and/or biologically active molecules and it helps to produce materials which very much resembles to body's native tissue/tissues. From tissue engineering current therapies got revolutionised and life quality of several millions patient got improved. Tissue engineering is the connecting discipline between engineering materials science, medicine and biology. In typical tissue engineering cells are seeded on biomimicked scaffold providing adhesive surfaces, then cells deposit their own protein to make them more biocompatible, but unable to vascularise properly, lack of functional cells, low mechanical strength of engineered cells, not immunologically compatible with host and Nutrient limitation are a classical issue in the field of tissue and tissue engineering. Through the article we will understand the technology involved, need and application of nanobiotechnology based tissue engineering.