The Experts below are selected from a list of 10359 Experts worldwide ranked by ideXlab platform
Vicki H Grassian - One of the best experts on this subject based on the ideXlab platform.
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Titanium Dioxide Nanoparticle surface reactivity with atmospheric gases co2 so2 and no2 roles of surface hydroxyl groups and adsorbed water in the formation and stability of adsorbed products
Journal of Physical Chemistry C, 2014Co-Authors: Charith E Nanayakkara, Whitney A Larish, Vicki H GrassianAbstract:The reactivity of O–H groups on Titanium Dioxide Nanoparticle surfaces with gas-phase carbon Dioxide, sulfur Dioxide, and nitrogen Dioxide is compared. Carbon Dioxide, sulfur Dioxide, and nitrogen Dioxide react with ca. 5, 50, and nearly 100%, respectively, of all hydroxyl groups on the surface at 298 K. As shown here, the surface reactivity of O–H groups with these three triatomic gases differs considerably due to different reaction mechanisms for adsorption and surface chemistry. In addition to investigating O–H group reactivity, the role of adsorbed water in the stability of different surface species that form from adsorption of carbon Dioxide, nitrogen Dioxide, and sulfur Dioxide on hydroxylated TiO2 Nanoparticles is probed as a function of relative humidity as is quantitative measurements of water uptake on TiO2 Nanoparticles before and after surface reaction. These water uptake studies provide insights into the stability of adsorbed species on oxide surfaces under atmospherically relevant conditions...
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Sulfur Dioxide adsorption and photooxidation on isotopically-labeled Titanium Dioxide Nanoparticle surfaces: roles of surface hydroxyl groups and adsorbed water in the formation and stability of adsorbed sulfite and sulfate
Physical chemistry chemical physics : PCCP, 2012Co-Authors: Charith E Nanayakkara, John M. Pettibone, Vicki H GrassianAbstract:Transmission FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS) are used to probe the details of sulfur Dioxide adsorption and photooxidation on Titanium Dioxide Nanoparticle surfaces. Adsorption sites, surface speciation and photooxidation chemistry have been determined from analysis of FTIR spectra in conjunction with isotope labeling experiments. These data show that surface hydroxyl groups are involved in the adsorption of sulfur Dioxide, and in particularly, sulfur Dioxide reacts with either one surface O–H group to yield adsorbed bisulfite or two surface O–H groups to yield adsorbed sulfite and water. Using 16O–H, 16O–D and 18O–H labeled surface O–H groups, additional insights into the adsorption mechanism as well as shifts in the vibrational modes of adsorbed sulfite have been determined. Upon irradiation, adsorbed sulfite/bisulfite converts to adsorbed sulfate. The relative stability of adsorbed sulfite to adsorbed sulfate on TiO2 Nanoparticle surfaces was also examined in the presence of increasing relative humidity (RH). It is shown here that adsorbed water can more easily displace sulfite compared to sulfate by forming a stable sulfur Dioxide water complex in the presence of adsorbed water. These differences in the RH-dependent stability of adsorbed species that form as a result of surface heterogeneous reactions on oxide particles surfaces has important implications in the heterogeneous chemistry of mineral dust aerosol in the atmosphere.
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Titanium Dioxide Nanoparticles: Grassian et al. Respond
Environmental health perspectives, 2008Co-Authors: Vicki H Grassian, John M. Pettibone, Patrick T. O'shaughnessy, Andrea Adamcakova-dodd, Peter S. ThorneAbstract:Baveye and Laba have further analyzed the transmission electron micrograph (TEM) image shown in Figure 2A of our article (Grassian et al. (2007b) to quantitatively determine the extent of Titanium Dioxide Nanoparticle clustering in the image by calculating the radial distribution function. The main point of doing this calculation was to demonstrate that TiO2 Nanoparticle aggregates will not completely deaggregate even when subjected to harsh conditions.
Frédérick Barreau - One of the best experts on this subject based on the ideXlab platform.
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Titanium Dioxide Nanoparticle impact and translocation through ex vivo in vivo and in vitro gut epithelia
Particle and Fibre Toxicology, 2014Co-Authors: Emilie Brun, Frédérick Barreau, Giulia Veronesi, Barbara Fayard, Stéphanie Sorieul, Corinne Chanéac, Christine CarapitoAbstract:TiO2 particles are commonly used as dietary supplements and may contain up to 36% of nano-sized particles (TiO2-NPs). Still impact and translocation of NPs through the gut epithelium is poorly documented. We show that, in vivo and ex vivo, agglomerates of TiO2-NPs cross both the regular ileum epithelium and the follicle-associated epithelium (FAE) and alter the paracellular permeability of the ileum and colon epithelia. In vitro, they accumulate in M-cells and mucus-secreting cells, much less in enterocytes. They do not cause overt cytotoxicity or apoptosis. They translocate through a model of FAE only, but induce tight junctions remodeling in the regular ileum epithelium, which is a sign of integrity alteration and suggests paracellular passage of NPs. Finally we prove that TiO2-NPs do not dissolve when sequestered up to 24 h in gut cells. Taken together these data prove that TiO2-NPs would possibly translocate through both the regular epithelium lining the ileum and through Peyer’s patches, would induce epithelium impairment, and would persist in gut cells where they would possibly induce chronic damage.
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Titanium Dioxide Nanoparticle impact and translocation through ex vivo, in vivo and in vitro gut epithelia.
Particle and Fibre Toxicology, 2014Co-Authors: Emilie Brun, Frédérick Barreau, Giulia Veronesi, Barbara Fayard, Stéphanie Sorieul, Corinne Chanéac, Christine Carapito, Thierry Rabilloud, Aloïse Mabondzo, Nathalie Herlin-boimeAbstract:BACKGROUND: TiO2 particles are commonly used as dietary supplements and may contain up to 36% of nano-sized particles (TiO2-NPs). Still impact and translocation of NPs through the gut epithelium is poorly documented. RESULTS: We show that, in vivo and ex vivo, agglomerates of TiO2-NPs cross both the regular ileum epithelium and the follicle-associated epithelium (FAE) and alter the paracellular permeability of the ileum and colon epithelia. In vitro, they accumulate in M-cells and mucus-secreting cells, much less in enterocytes. They do not cause overt cytotoxicity or apoptosis. They translocate through a model of FAE only, but induce tight junctions remodeling in the regular ileum epithelium, which is a sign of integrity alteration and suggests paracellular passage of NPs. Finally we prove that TiO2-NPs do not dissolve when sequestered up to 24 h in gut cells. CONCLUSIONS: Taken together these data prove that TiO2-NPs would possibly translocate through both the regular epithelium lining the ileum and through Peyer's patches, would induce epithelium impairment, and would persist in gut cells where they would possibly induce chronic damage.
Ashutosh Kumar - One of the best experts on this subject based on the ideXlab platform.
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Titanium Dioxide Nanoparticle-protein interaction explained by docking approach.
International journal of nanomedicine, 2018Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Chidambaram Ramalingam, C. Sudandiradoss, Ashutosh KumarAbstract:Titanium Dioxide has been proven for toxicity by in vitro and in vivo approaches, however, further studies are needed in nano-toxicological research using in silico analysis. In this study, Autodock 4.0.5 was used in an attempt to evaluate the interaction of Titanium Dioxide with proteins. Different cellular proteins were sorted to study the interaction, binding sites, and active sites as a pocket. These pockets have been determined using CastP - an online server. The analysis for the docked structures was performed with regard to the most efficient binding with amino acids. This study is the first of its kind to report on the in silico docking interaction of Titanium Dioxide Nanoparticles without any surface modification. The higher negative binding energy shows strong binding of Titanium Dioxide with proteins. A strong interaction with different cellular proteins was observed, and more specifically, Titanium Dioxide Nanoparticles showed frequent interaction with proline, lysine, as well as leusine.
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A Novel Approach to Evaluate Titanium Dioxide Nanoparticle–Protein Interaction Through Docking: An Insight into Mechanism of Action
2017Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Sudandiradoss Chinnappan, Chidambaram Ramalingam, Ashutosh KumarAbstract: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.
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a novel approach to evaluate Titanium Dioxide Nanoparticle protein interaction through docking an insight into mechanism of action
Proceedings of the National Academy of Sciences India Section B: Biological Sciences, 2017Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Sudandiradoss Chinnappan, Chidambaram Ramalingam, Ashutosh KumarAbstract: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.
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microwave irradiation assisted hybrid chemical approach for Titanium Dioxide Nanoparticle synthesis microbial and cytotoxicological evaluation
Environmental Science and Pollution Research, 2016Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Chidambaram Ramalingam, Bhavapriya Rajendran, G S Avadhani, Ashutosh KumarAbstract: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.
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Titanium Dioxide Nanoparticle induced oxidative stress triggers dna damage and hepatic injury in mice
Nanomedicine: Nanotechnology Biology and Medicine, 2014Co-Authors: Ritesh K Shukla, Ashutosh Kumar, Naga Veera Srikanth Vallabani, Alok K Pandey, Alok DhawanAbstract:Background: The use of metal oxide Nanoparticles (Titanium Dioxide) in consumer and industrial products improves their quality but also underscores the possible adverse effects to human and environmental health. Materials & methods: Mice were exposed orally for 14 consecutive days and analyzed for alteration in different hepatic enzymes, histopathological changes, oxidative stress, DNA damage, tumor suppressor and proapoptotic protein expression in liver cells. Results: We observed a significant alteration in the level of hepatic enzymes and liver histopathology at a dose of 100 mg/kg body weight. Significant oxidative DNA damage was observed in liver cells, which could be attributed to oxidative stress. In addition, the increased expression of p53, BAX, caspase-3 and -9 proteins and decreased expression of antiapoptotic protein Bcl-2, suggest activation of the intrinsic pathway of apoptosis. Conclusion: High accumulation of Titanium Dioxide Nanoparticles in the liver tissue would cause DNA damage and apo...
Christine Carapito - One of the best experts on this subject based on the ideXlab platform.
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Titanium Dioxide Nanoparticle impact and translocation through ex vivo in vivo and in vitro gut epithelia
Particle and Fibre Toxicology, 2014Co-Authors: Emilie Brun, Frédérick Barreau, Giulia Veronesi, Barbara Fayard, Stéphanie Sorieul, Corinne Chanéac, Christine CarapitoAbstract:TiO2 particles are commonly used as dietary supplements and may contain up to 36% of nano-sized particles (TiO2-NPs). Still impact and translocation of NPs through the gut epithelium is poorly documented. We show that, in vivo and ex vivo, agglomerates of TiO2-NPs cross both the regular ileum epithelium and the follicle-associated epithelium (FAE) and alter the paracellular permeability of the ileum and colon epithelia. In vitro, they accumulate in M-cells and mucus-secreting cells, much less in enterocytes. They do not cause overt cytotoxicity or apoptosis. They translocate through a model of FAE only, but induce tight junctions remodeling in the regular ileum epithelium, which is a sign of integrity alteration and suggests paracellular passage of NPs. Finally we prove that TiO2-NPs do not dissolve when sequestered up to 24 h in gut cells. Taken together these data prove that TiO2-NPs would possibly translocate through both the regular epithelium lining the ileum and through Peyer’s patches, would induce epithelium impairment, and would persist in gut cells where they would possibly induce chronic damage.
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Titanium Dioxide Nanoparticle impact and translocation through ex vivo, in vivo and in vitro gut epithelia.
Particle and Fibre Toxicology, 2014Co-Authors: Emilie Brun, Frédérick Barreau, Giulia Veronesi, Barbara Fayard, Stéphanie Sorieul, Corinne Chanéac, Christine Carapito, Thierry Rabilloud, Aloïse Mabondzo, Nathalie Herlin-boimeAbstract:BACKGROUND: TiO2 particles are commonly used as dietary supplements and may contain up to 36% of nano-sized particles (TiO2-NPs). Still impact and translocation of NPs through the gut epithelium is poorly documented. RESULTS: We show that, in vivo and ex vivo, agglomerates of TiO2-NPs cross both the regular ileum epithelium and the follicle-associated epithelium (FAE) and alter the paracellular permeability of the ileum and colon epithelia. In vitro, they accumulate in M-cells and mucus-secreting cells, much less in enterocytes. They do not cause overt cytotoxicity or apoptosis. They translocate through a model of FAE only, but induce tight junctions remodeling in the regular ileum epithelium, which is a sign of integrity alteration and suggests paracellular passage of NPs. Finally we prove that TiO2-NPs do not dissolve when sequestered up to 24 h in gut cells. CONCLUSIONS: Taken together these data prove that TiO2-NPs would possibly translocate through both the regular epithelium lining the ileum and through Peyer's patches, would induce epithelium impairment, and would persist in gut cells where they would possibly induce chronic damage.
Shivendu Ranjan - One of the best experts on this subject based on the ideXlab platform.
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Titanium Dioxide Nanoparticle-protein interaction explained by docking approach.
International journal of nanomedicine, 2018Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Chidambaram Ramalingam, C. Sudandiradoss, Ashutosh KumarAbstract:Titanium Dioxide has been proven for toxicity by in vitro and in vivo approaches, however, further studies are needed in nano-toxicological research using in silico analysis. In this study, Autodock 4.0.5 was used in an attempt to evaluate the interaction of Titanium Dioxide with proteins. Different cellular proteins were sorted to study the interaction, binding sites, and active sites as a pocket. These pockets have been determined using CastP - an online server. The analysis for the docked structures was performed with regard to the most efficient binding with amino acids. This study is the first of its kind to report on the in silico docking interaction of Titanium Dioxide Nanoparticles without any surface modification. The higher negative binding energy shows strong binding of Titanium Dioxide with proteins. A strong interaction with different cellular proteins was observed, and more specifically, Titanium Dioxide Nanoparticles showed frequent interaction with proline, lysine, as well as leusine.
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A Novel Approach to Evaluate Titanium Dioxide Nanoparticle–Protein Interaction Through Docking: An Insight into Mechanism of Action
2017Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Sudandiradoss Chinnappan, Chidambaram Ramalingam, Ashutosh KumarAbstract: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.
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a novel approach to evaluate Titanium Dioxide Nanoparticle protein interaction through docking an insight into mechanism of action
Proceedings of the National Academy of Sciences India Section B: Biological Sciences, 2017Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Sudandiradoss Chinnappan, Chidambaram Ramalingam, Ashutosh KumarAbstract: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.
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a spectroscopic study on interaction between bovine serum albumin and Titanium Dioxide Nanoparticle synthesized from microwave assisted hybrid chemical approach
Journal of Photochemistry and Photobiology B-biology, 2016Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Priyanka Srivastava, Chidambaram RamalingamAbstract: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 20min. 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 20min. The data of the present study determines the detailed evaluation of BSA adsorption on TiO2 Nanoparticle along with mechanism and adsorption kinetics.
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microwave irradiation assisted hybrid chemical approach for Titanium Dioxide Nanoparticle synthesis microbial and cytotoxicological evaluation
Environmental Science and Pollution Research, 2016Co-Authors: Shivendu Ranjan, Nandita Dasgupta, Chidambaram Ramalingam, Bhavapriya Rajendran, G S Avadhani, Ashutosh KumarAbstract: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.