Cytotoxicity study of Piper nigrum seed mediated synthesized SnO2 nanoparticles towards colorectal (HCT116) and lung cancer (A549) cell lines

Copper/Tin Nanocomposites-Loaded Exosomes Induce Apoptosis and Cell Cycle Arrest at G0/G1 Phase in Skin Cancer Cell Line

This study aims to explore the efficacy of Copper/Tin (CuS/SnS) nanocomposites loaded into exosomes against skin cancer A431 cell line. CuS/SnS nanocomposites (S1, S2, S3) were synthesized and characterized, then loaded into exosomes (Exo) (S1-Exo, S2-Exo and S3-Exo) and characterized. After that, the loaded samples were investigated in vitro against A431 using cytotoxicity, apoptosis, and cell cycle assays. CuS/SnS nanocomposites were indexed to hexagonal CuS structure and orthorhombic α-SnS phase and showed nano-rode shape. The exosomes loaded with nanocomposites were regular and rounded within the size of 120 nm, with no signs of broken exosomes or leakage of their contents. The cytotoxicity assay indicated the enhanced cytotoxic of S1-Exo versus the free nano-form S1 on A431. Interestingly, S1-Exo recorded 1.109 times more than DOX in its anti-skin cancer capacity. Moreover, S1-Exo recorded 40.2 % for early apoptosis and 22.1 % for late apoptosis. Furthermore, it displayed impact in arresting the cancer cell cycle at G0/G1 phase and reducing G2/M phase. Noteworthy, loaded nanocomposites were safe against normal HSF skin cells. In conclusion, the loaded CuS/SnS nanocomposites into the exosomes could be of great potential as anti-skin cancer candidates through induction of apoptosis and promotion of the cell cycle arrest at G0/G1 phase.

Applications and advancements of nanoparticle-based drug delivery in alleviating lung cancer and chronic obstructive pulmonary disease

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are among the leading causes of mortality worldwide. Cigarette smoking is among the main aetiologic factors for both ailments. These diseases share common pathogenetic mechanisms including inflammation, oxidative stress, and tissue remodelling. Current therapeutic approaches are limited by low efficacy and adverse effects. Consequentially, LC has a 5-year survival of < 20%, while COPD is incurable, underlining the necessity for innovative treatment strategies. Two promising emerging classes of therapy against these diseases include plant-derived molecules (phytoceuticals) and nucleic acid-based therapies. The clinical application of both is limited by issues including poor solubility, poor permeability, and, in the case of nucleic acids, susceptibility to enzymatic degradation, large size, and electrostatic charge density. Nanoparticle-based advanced drug delivery systems are currently being explored as flexible systems allowing to overcome these limitations. In this review, an updated summary of the most recent studies using nanoparticle-based advanced drug delivery systems to improve the delivery of nucleic acids and phytoceuticals for the treatment of LC and COPD is provided. This review highlights the enormous relevance of these delivery systems as tools that are set to facilitate the clinical application of novel categories of therapeutics with poor pharmacokinetic properties.

Employing Piper longum extract for eco-friendly fabrication of PtPd alloy nanoclusters: advancing electrolytic performance of formic acid and methanol oxidation

Advancement in bioinspired alloy nanomaterials has a crucial impact on fuel cell applications. Here, we report the synthesis of PtPd alloy nanoclusters via the hydrothermal method using Piper longum extract, representing a novel and environmentally friendly approach. Physicochemical characteristics of the synthesized nanoclusters were investigated using various instrumentation techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, and High-Resolution Transmission electron microscopy. The electrocatalytic activity of the biogenic PtPd nanoclusters towards the oxidation of formic acid and methanol was evaluated chronoamperometry and cyclic voltammetry studies. The surface area of the electrocatalyst was determined to be 36.6 m2g-1 by Electrochemical Surface Area (ECSA) analysis. The biologically inspired PtPd alloy nanoclusters exhibited significantly higher electrocatalytic activity compared to commercial Pt/C, with specific current responses of 0.24 mA cm - 2 and 0.17 mA cm - 2 at synthesis temperatures of 180 °C and 200 °C, respectively, representing approximately four times higher oxidation current after 120 min. This innovative synthesis approach offers a promising pathway for the development of PtPd alloy nanoclusters with enhanced electrocatalytic activity, thereby advancing fuel cell technology towards a sustainable energy solution.

Cytotoxicity prediction of nano metal oxides on different lung cells via Nano-QSAR

In recent years, nanomaterials have found extensive applications across diverse domains owing to their distinctive physical and chemical characteristics. It is of great importance in theoretical and practical terms to carry out the relationship between structural characteristics of nanomaterials and different cytotoxicity and to achieve practical assessment and prediction of cytotoxicity. This study investigated the intrinsic quantitative constitutive relationships between the cytotoxicity of nano-metal oxides on human normal lung epithelial cells and human lung adenocarcinoma cells. We first employed quasi-SMILES-based nanostructural descriptors by selecting the five physicochemical properties that are most closely related to the cytotoxicity of nanometal oxides, then established SMILES-based descriptors that can effectively describe and characterize the molecular structure of nanometal oxides, and then built the corresponding Nano-Quantitative Structure-Activity Relationship (Nano-QSAR) prediction models, finally, combined with the theory of reactive oxygen species (ROS) biotoxicity, to reveal the mechanism of toxicity and differences between the two cell types. The established model can efficiently and accurately predict the properties of targets, reveal the corresponding toxicity mechanisms, and guide the safe design, synthesis, and application of nanometal oxides.

Pure red upconverted and near-infrared luminescence properties of Er3+ -doped SnO2 nanocrystals for lighting applications

Tin oxide (SnO2 ) nanocrystalline powders doped with erbium ion (Er3+ ) in different molar ratios (0, 3, 5, and 7 mol%) were prepared using a solid-state reaction technique. These samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible absorption, visible upconversion, and near-infrared luminescence techniques. XRD analysis revealed the tetragonal rutile structure of SnO2 and the average crystallite size was about 32 nm. From Tauc's plots, it was confirmed that the substitution of Er3+ ions into the SnO2 host lattice resulted in the narrowing its band gap. Optical absorption bands at 520 and 654 nm correspond to the 4f electron transitions of Er3+ further confirming visible light absorption. Infrared luminescence spectra showed a broad band centred at 1536 nm which is assigned to the 4 I13/2  → 4 I15/2 transition of Er3+ . Visible upconverted emission spectra under 980 nm excitation exhibit a strong red luminescence with a main peak at 672 nm which is attributed to the 4 F9/2  → 4 I15/2 transition of Er3+ . Power-dependent upconversion spectra confirmed that two photons participated in the upconversion mechanism. Enhancement in the intensities of both visible and infrared luminescence was observed when raising the concentration. The results pave the way for the potential applications of these nanocrystalline powders in energy harvesting applications such as infrared light upconverting layer in solar cells, light emitting diodes, infrared broadband sources and amplifiers, and biological labelling.

Carboxymethylcellulose/Agar-Based Multifunctional Films Incorporated with Zn-Doped SnO2 Nanoparticles for Active Food Packaging Application

SnO2 and Zn-SnO2 nanoparticles were prepared by chemical precipitation, and the rutile phase of SnO2 was confirmed through X-ray diffraction studies. X-ray photoelectron spectroscopy (XPS) confirmed the doping of SnO2 with Zn and elucidated the surface chemistry before and after doping. The average sizes of SnO2 and Zn-SnO2 nanoparticles determined using TEM were 3.96 ± 0.85 and 3.72 ± 0.9 nm, respectively. UV-visible and photoluminescence spectrophotometry were used to evaluate the optical properties of SnO2 and Zn-SnO2 nanoparticles, and their energy gaps (Eg) were 3.8 and 3.9 eV, respectively. The antibacterial activity of these nanoparticles against Salmonella enterica and Staphylococcus aureus was evaluated under dark and light conditions. Antibacterial activity was higher in light, showing the highest activity (99.5%) against S. enterica. Carboxymethylcellulose (CMC)/agar-based functional composite films were prepared by adding different amounts of SnO2 and Zn-SnO2 nanoparticles (1 and 3 wt % of polymers). The composite film showed significantly increased UV barrier properties while maintaining the mechanical properties, water vapor barrier, and transparency compared to the neat CMC/agar film. These composite films showed significant antibacterial activity; however, the Zn-SnO2-added film showed stronger antibacterial activity (99.2%) than the SnO2-added film (15%).

Theoretical and Experimental Study of the Photocatalytic Properties of ZnO Semiconductor Nanoparticles Synthesized by Prosopis laevigata

In this work, the photocatalytic activity of nanoparticles (NPs) of zinc oxide synthetized by Prosopis laevigata as a stabilizing agent was evaluated in the degradation of methylene blue (MB) dye under UV radiation. The theoretical study of the photocatalytic degradation process was carried out by a Langmuir-Hinshelwood-Hougen-Watson (LHHW) model. Zinc oxide nanoparticles were synthesized by varying the concentration of natural extract of Prosopis laevigata from 1, 2, and 4% (weight/volume), identifying the samples as ZnO_PL1%, ZnO_PL2%, and ZnO_PL4%, respectively. The characterization of the nanoparticles was carried out by Fourier transform infrared spectroscopy (FT-IR), where the absorption band for the Zn-O vibration at 400 cm-1 was presented; by ultraviolet-visible spectroscopy (UV-vis) the value of the band gap was calculated, resulting in 2.80, 2.74 and 2.63 eV for the samples ZnO_PL1%, ZnO_PL2%, and ZnO_PL4%, respectively; XRD analysis indicated that the nanoparticles have a hexagonal zincite crystal structure with an average crystal size of 55, 50, and 49 in the sample ZnO_PL1%, ZnO_PL2%, and ZnO_PL4%, respectively. The morphology observed by TEM showed that the nanoparticles had a hemispherical shape, and the ZnO_PL4% sample presented sizes ranging between 29 and 45 nm. The photocatalytic study showed a total degradation of the MB in 150, 120, and 60 min for the samples ZnO_PL1%, ZnO_PL2%, and ZnO_PL4%, respectively. Also, the model explains the experimental observation of the first-order kinetic model in the limit of low concentrations of dye, indicating the influence of the mass transfer processes.

Photocatalytic degradation of organic pollutants and inactivation of pathogens under visible light via SnO2/rGO composites

The domains of environmental cleanup and pathogen inactivation are particularly interesting in nanocomposites (NCs) due to their exceptional physicochemical properties. Tin oxide/reduced graphene oxide nanocomposites (SnO₂/rGO NCs) have potential uses in the biological and environmental fields, but little is known about them. This study aimed to investigate the photocatalytic activity and antibacterial efficiency of the nanocomposites. The co-precipitation technique was used to prepare all the samples. XRD, SEM, EDS, TEM, and XPS analyses were employed to characterize the physicochemical properties of SnO₂/rGO NCs for structural analysis. The rGO loading sample resulted in a decrease in the crystallite size of SnO₂ nanoparticles. TEM and SEM images demonstrate the firm adherence of SnO₂ nanoparticles to the rGO sheets. The chemical state and elemental composition of the nanocomposites were validated by the XPS and EDS data. Additionally, the visible-light active photocatalytic and antibacterial capabilities of the synthesized nanocomposites were assessed for the degradation of Orange II and methylene blue, as well as the suppression of the growth of S. aureus and E. coli. As a result, the synthesized SnO₂/rGO NCs are improved photocatalysts and antibacterial agents, expanding their potential in the fields of environmental remediation and water disinfection.

Pluronic-F-127-Passivated SnO2 Nanoparticles Derived by Using Polygonum cuspidatum Root Extract: Synthesis, Characterization, and Anticancer Properties

Nanotechnology has emerged as the most popular research topic with revolutionary applications across all scientific disciplines. Tin oxide (SnO₂) has been gaining considerable attention lately owing to its intriguing features, which can be enhanced by its synthesis in the nanoscale range. The establishment of a cost-efficient and ecologically friendly procedure for its production is the result of growing concerns about human well-being. The novelty and significance of this study lie in the fact that the synthesized SnO₂ nanoparticles have been tailored to have specific properties, such as size and morphology. These properties are crucial for their applications. Moreover, this study provides insights into the synthesis process of SnO₂ nanoparticles, which can be useful for developing efficient and cost-effective methods for large-scale production. In the current study, green Pluronic-coated SnO₂ nanoparticles (NPs) utilizing the root extracts of Polygonum cuspidatum have been formulated and characterized by several methods such as UV-visible, Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDAX), transmission electron microscope (TEM), field emission-scanning electron microscope (FE-SEM), X-ray diffraction (XRD), photoluminescence (PL), and dynamic light scattering (DLS) studies. The crystallite size of SnO₂ NPs was estimated to be 45 nm, and a tetragonal rutile-type crystalline structure was observed. FESEM analysis validated the NPs' spherical structure. The cytotoxic potential of the NPs against HepG2 cells was assessed using the in vitro MTT assay. The apoptotic efficiency of the NPs was evaluated using a dual-staining approach. The NPs revealed substantial cytotoxic effects against HepG2 cells but failed to exhibit cytotoxicity in different liver cell lines. Furthermore, dual staining and flow cytometry studies revealed higher apoptosis in NP-treated HepG2 cells. Nanoparticle treatment also inhibited the cell cycle at G0/G1 stage. It increased oxidative stress and promoted apoptosis by encouraging pro-apoptotic protein expression in HepG2 cells. NP treatment effectively blocked the PI3K/Akt/mTOR axis in HepG2 cells. Thus, green Pluronic-F-127-coated SnO₂ NPs exhibits enormous efficiency to be utilized as an talented anticancer agent.

Natural sunlight driven photocatalytic dye degradation by biogenically synthesized tin oxide (SnO2) nanostructures using Tinospora crispa stem extract and its anticancer and antibacterial applications

In the present study, tin oxide (SnO₂) was synthesized by advocating the principles of green chemistry for the photo-mediated degradation of pollutants, antimicrobial, and as an antitumor agent. Bioactive SnO₂ (nanorods & nanospheres) were fabricated using Tinospora crispa stem extract (TCSE) via sol-gel technique and characterized extensively. XRD, UV-VIS, FTIR, and XPS studies confirmed the formation of crystalline and well stoichiometric pure phase of SnO₂ nanostructures with optical bandgap 3.2 to 3.5 eV. The transmission electron microscopy (TEM) results demonstrated the effect of secondary phytoconstituents on the shape of SnO₂ in a concentration dependent manner. The morphological variations in the obtained nanostructures attributed to the nucleation density and coalescence effect leading to the formation of nanorods with an average diameter 23-25 nm whereas the average particle size of the nanospheres obtained was found to be 23-30 nm. The zeta potential value of SnO₂ nanorods was high (- 58.9 mV) indicating the higher stability compared to nanospheres (- 15.6 mV). The SnO₂ nanostructures were investigated for the simultaneous degradation of methylene blue with degradation efficiency of 92.3% and 47.3% for rhodamine B in mono system and 72.3%, 47.7% respectively for binary dye system. The anticancer activity of SnO₂ nanorods explored against human breast cancer (MCF-7) cells revealed a concentration dependent cytotoxic effect reactive oxygen species (ROS) induced cell death. Additionally, efficient antibacterial activity of SnO₂ was established using E.coli. Multifaceted applications of Tinospora crispa stem extract mediated SnO₂ nanostructures.

SnO2 and CuO anchored on zeolite as an efficient heterojunction photocatalyst for sunlight-assisted degradation of cefixime

The fabrication of heterojunction nanocomposites has been proven as a highly efficient strategy to achieve promising photocatalysts. In this study, tin oxide (SnO₂) and copper oxide (CuO) nanoparticles (NPs) were synthesized in situ using Rosmarinus officinalis and simultaneously anchored on zeolite for the fabrication of zeolite/SnO₂/CuO as a novel heterojunction photocatalyst. The performance of zeolite/SnO₂/CuO was assessed against photodegradation of cefixime as a model pharmaceutical contaminant. A good catalytic potential and synergistic effect was obtained for zeolite/SnO₂/CuO compared to pure SnO₂ and CuO NPs. Under optimum conditions, 89.65% of cefixime was degraded after 2.5 h under natural sunlight. Based on radical quenching experiments, the importance of involved oxidizing species in the photodegradation of cefixime using zeolite/SnO₂/CuO was in order of h⁺ > ^•OH > [Formula: see text]. Among studied anions, the highest inhibitory effect was observed for nitrate ion. Also, the main intermediates of the photodegradation process of cefixime in zeolite/SnO₂/CuO system were determined by HPLC-MS and the possible pathways were suggested. More than 83% cefixime was removed after three catalyst reuse cycles, indicating a cost-effectiveness potential in the reusability of zeolite/SnO₂/CuO. Also, the toxicity and plant growth tests revealed the feasibility of discharging the treated cefixime solutions to irrigate agricultural crops. Overall, the obtained results provide a promising technique with a synergistic feature for the efficient removal of organic pollutants.

Self-Therapeutic Nanomaterials: Applications in Biology and Medicine

Over past decades, nanotechnology has contributed to the biomedical field in areas including detection, diagnosis, and drug delivery via opto-electronic properties or enhancement of biological effects. Though generally considered inert delivery vehicles, a plethora of past and present evidence demonstrates that nanomaterials also exude unique intrinsic biological activity based on composition, shape, and surface functionalization. These intrinsic biological activities, termed self-therapeutic properties, take several forms, including mediation of cell-cell interactions, modulation of interactions between biomolecules, catalytic amplification of biochemical reactions, and alteration of biological signal transduction events. Moreover, study of biomolecule-nanomaterial interactions offers a promising avenue for uncovering the molecular mechanisms of biology and the evolution of disease. In this review, we observe the historical development, synthesis, and characterization of self-therapeutic nanomaterials. Next, we discuss nanomaterial interactions with biological systems, starting with administration and concluding with elimination. Finally, we apply this materials perspective to advances in intrinsic nanotherapies across the biomedical field, from cancer therapy to treatment of microbial infections and tissue regeneration. We conclude with a description of self-therapeutic nanomaterials in clinical trials and share our perspective on the direction of the field in upcoming years.

Synthesis of N-doped carbon dots for highly selective and sensitive detection of metronidazole in real samples and its cytotoxicity studies

The current investigation reports the synthesis of N-CDs using glucosamine, ascorbic acid, and ethylenediamine precursors by a simple hydrothermal technique. The formation of N-CDs was proved by various characterisation techniques such as X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Fourier-Transform Infrared Spectrophotometer (FT-IR). The optical properties were investigated by fluorescence and UV-vis spectrophotometer. Also, N-CDs showed high selectivity in detecting the MTZ compared to several other analytes. However, the metronidazole serves as an antibiotic against several microbial diseases but also a genotoxic, carcinogenic to the human when used in excessive dosage. The synthesised N-CDs showed high selectivity in detecting the MTZ compared to several other analytes. Besides, the cytotoxicity of the N-CDs was studied to evaluate its toxicity against the HeLa cancer cells. It showed 65.6% cell viability and 34.3% toxicity against the cancerous cells, and similarly 71% of cells viability against H9C2 cells. Thus, the current investigation explores the promising selective sensing of N-CDs against MTZ, along with that, it proved its cytotoxicity against HeLa cancerous cells and non-toxicity against H9C2 cells. The synthesised CDs can be better MTZ sensors and anti-cancer agents on further development at the industrial scale.

A spotlight on alkaloid nanoformulations for the treatment of lung cancer

Numerous naturally available phytochemicals have potential anti-cancer activities due to their vast structural diversity. Alkaloids have been extensively used in cancer treatment, especially lung cancers, among the plant-based compounds. However, their utilization is limited by their poor solubility, low bioavailability, and inadequacies such as lack of specificity to cancer cells and indiscriminate distribution in the tissues. Incorporating the alkaloids into nanoformulations can overcome the said limitations paving the way for effective delivery of the alkaloids to the site of action in sufficient concentrations, which is crucial in tumor targeting. Our review attempts to assess whether alkaloid nanoformulation can be an effective tool in lung cancer therapy. The mechanism of action of each alkaloid having potential is explored in great detail in the review. In general, Alkaloids suppress oncogenesis by modulating several signaling pathways involved in multiplication, cell cycle, and metastasis, making them significant component of many clinical anti-cancerous agents. The review also explores the future prospects of alkaloid nanoformulation in lung cancer. So, in conclusion, alkaloid based nanoformulation will emerge as a potential gamechanger in treating lung cancer in the near future.

Combination Anticancer Therapies Using Selected Phytochemicals

Cancer is still one of the most widespread diseases globally, it is considered a vital health challenge worldwide and one of the main barriers to long life expectancy. Due to the potential toxicity and lack of selectivity of conventional chemotherapeutic agents, discovering alternative treatments is a top priority. Plant-derived natural products have high potential in cancer treatment due to their multiple mechanisms of action, diversity in structure, availability in nature, and relatively low toxicity. In this review, the anticancer mechanisms of the most common phytochemicals were analyzed. Furthermore, a detailed discussion of the anticancer effect of combinations consisting of natural product or natural products with chemotherapeutic drugs was provided. This review should provide a strong platform for researchers and clinicians to improve basic and clinical research in the development of alternative anticancer medicines.

One-Pot Synthesis of SnO2-rGO Nanocomposite for Enhanced Photocatalytic and Anticancer Activity

Metal oxide and graphene derivative-based nanocomposites (NCs) are attractive to the fields of environmental remediation, optics, and cancer therapy owing to their remarkable physicochemical characteristics. There is limited information on the environmental and biomedical applications of tin oxide-reduced graphene oxide nanocomposites (SnO₂-rGO NCs). The goal of this work was to explore the photocatalytic activity and anticancer efficacy of SnO₂-rGO NCs. Pure SnO₂ NPs and SnO₂-rGO NCs were prepared using the one-pot hydrothermal method. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), UV–Vis spectrometry, photoluminescence (PL), and Raman scattering microscopy were applied to characterize the synthesized samples. The crystallite size of the SnO₂ NPs slightly increased after rGO doping. TEM and SEM images show that the SnO₂ NPs were tightly anchored onto the rGO sheets. The XPS and EDX data confirmed the chemical state and elemental composition of the SnO₂-rGO NCs. Optical data suggest that the bandgap energy of the SnO₂-rGO NCs was slightly lower than for the pure SnO₂ NPs. In comparison to pure SnO₂ NPs, the intensity of the PL spectra of the SnO₂-rGO NCs was lower, indicating the decrement of the recombination rate of the surfaces charges (e⁻/h⁺) after rGO doping. Hence, the degradation efficiency of methylene blue (MB) dye by SnO₂-rGO NCs (93%) was almost 2-fold higher than for pure SnO₂ NPs (54%). The anticancer efficacy of SnO₂-rGO NCs was also almost 1.5-fold higher against human liver cancer (HepG2) and human lung cancer (A549) cells compared to the SnO₂ NPs. This study suggests a unique method to improve the photocatalytic activity and anticancer efficacy of SnO₂ NPs by fusion with graphene derivatives.

H, G. L. B, Pradeepkiran JA, Padhy H. Sunflower-Assisted Bio-Derived ZnO-NPs as an Efficient Nanocatalyst for the Synthesis of Novel Quinazolines with Highly Antioxidant Activities

The present report presents a green method for the rapid biogenic synthesis of nanoparticles that offers several advantages over the current chemical and physical procedures. It is easy and fast, eco-friendly, and does not involve any precious elements, hazardous chemicals, or harmful solvents. The synthesized ZnO nanoparticles were characterized using different techniques, such as UV-Visible spectroscopy. The surface plasmon resonance confirmed the formation of ZnO nanoparticles at 344 nm, using UV-Visible spectroscopy. The leaf extract acts as a source of phytochemicals and is primarily used for the reduction and then the formation of stable ZnO nanoparticles by the characteristic functional groups of the extract; the synthesized ZnO nanoparticles were identified using FTIR spectroscopy. The crystalline nature of ZnO-NPs was confirmed via powder X-ray diffraction (XRD). Size and morphology were measured via high resolution transmission electron microscopy (HR-TEM) analysis. The stability of the nanoparticles is established using dynamic light scattering (DLS) and thermogravimetric analysis (TGA). The synthesized ZnO nanoparticles have been found to be a good and efficient catalyst for the synthesis of novel 1,2-dihydro quinazoline derivatives under the green method via a one-pot reaction of 2-amino benzophenone, 1,3-diphenyl-1H-pyrazole carbaldehydes, and ammonium acetate. The synthesized compounds (4a–o) were characterized by the ¹H NMR, ¹³C NMR, and HRMS spectra and were further validated for free-radical scavenging activity. The synthesized ZnO nanoparticles exhibited good antioxidant activity.

Recent progress of phytogenic synthesis of ZnO, SnO2, and CeO2 nanomaterials

A critical investigation on the fabrication of metal oxide nanoparticles (NPs) such as ZnO, SnO₂, and CeO₂ NPs synthesized from green and phytogenic method using plants and various plant parts have been compiled. In this review, different plant extraction methods, synthesis methods, characterization techniques, effects of plant extract on the physical, chemical, and optical properties of green synthesized ZnO, SnO₂, and CeO₂ NPs also have been compiled and discussed. Effect of several parameters on the size, morphology, and optical band gap energy of metal oxide have been explored. Moreover, the role of solvents has been found important and discussed. Extract composition i.e. phytochemicals also found to affect the morphology and size of the synthesized ZnO, SnO₂, and CeO₂ NPs. It was found that, there is no universal extraction method that is ideal and extraction techniques is unique to the plant type, plant parts, and solvent used.

Influence of natural organic matter on the transformation of metal and metal oxide nanoparticles and their ecotoxic potency in vitro

Increased use and production of engineered nanoparticles (NPs) lead to an elevated risk of their diffuse dispersion into the aquatic environment and increased concern on unknown effects induced by their release into the aquatic ecosystem. An improved understanding of the environmental transformation processes of NPs of various surface characteristics is hence imperative for risk assessment and management. This study presents results on effects of natural organic matter (NOM) on the environmental transformation and dissolution of metal and metal oxide NPs of different surface and solubility properties in synthetic freshwater (FW) with and without NOM. Adsorption of NOM was evident on most of the studied NPs, except Sb and Sb₂O₃, which resulted in the formation of negatively charged colloids of higher stability and smaller size distribution compared with the same NPs in FW only. The dissolution rate of the NPs in the presence of NOM correlated with the strength of interactions between the carboxylate group of NOM and the particle surface, and resulted in either no (Mn, Sb, ZnO NPs), increased (Co, Sn NPs) and decreased (Ni, NiO, Sb₂O₃, Y₂O₃ NPs) levels of dissolution. One type of metal NP from each group (Mn, Ni, Sn) were investigated to assess whether observed differences in adsorption of NOM and dissolution would influence their ecotoxic potency. The results showed Mn, Ni, and Sn NPs to generate intracellular reactive oxygen species (ROS) in a time and dose-dependent manner. The extent of ROS generation in FW was similar for both Mn and Ni NPs but higher for Sn NPs. These findings are possibly related to interactions and infiltration of the NPs with the cells, which lead to redox imbalances which could induce oxidative stress and cell damage. At the same time, the presence of NOM generally reduced the intracellular ROS generation by 20-40% for the investigated NPs and also reduced cytotoxicity of Sn NPs, which can be attributed to the stronger interaction of carboxylate groups of NOM with the surface of the NPs.

Essential Oil Nanoemulsion as Eco-Friendly and Safe Preservative: Bioefficacy Against Microbial Food Deterioration and Toxin Secretion, Mode of Action, and Future Opportunities

Microbes are the biggest shareholder for the quantitative and qualitative deterioration of food commodities at different stages of production, transportation, and storage, along with the secretion of toxic secondary metabolites. Indiscriminate application of synthetic preservatives may develop resistance in microbial strains and associated complications in human health with broad-spectrum environmental non-sustainability. The application of essential oils (EOs) as a natural antimicrobial and their efficacy for the preservation of foods has been of present interest and growing consumer demand in the current generation. However, the loss in bioactivity of EOs from fluctuating environmental conditions is a major limitation during their practical application, which could be overcome by encapsulating them in a suitable biodegradable and biocompatible polymer matrix with enhancement to their efficacy and stability. Among different nanoencapsulated systems, nanoemulsions effectively contribute to the practical applications of EOs by expanding their dispersibility and foster their controlled delivery in food systems. In line with the above background, this review aims to present the practical application of nanoemulsions (a) by addressing their direct and indirect (EO nanoemulsion coating leading to active packaging) consistent support in a real food system, (b) biochemical actions related to antimicrobial mechanisms, (c) effectiveness of nanoemulsion as bio-nanosensor with large scale practical applicability, (d) critical evaluation of toxicity, safety, and regulatory issues, and (e) market demand of nanoemulsion in pharmaceuticals and nutraceuticals along with the current challenges and future opportunities.

Core-shell Fe3O4@SnO2 nanochains toward the application of radar-infrared-visible compatible stealth

Multiband-compatible stealth materials play an increasingly crucial role in the field of modern military defence because they can enable the targeted objects to dodge advance detection technologies. In this study, chain-like Fe₃O₄@poly(ethyleneglycol dimethacrylate-co-methacrylic acid) nanocomposites were constructed as precursors through the magnetic field-induced distillation precipitation polymerisation. Then, the liquid-phase seed-mediated growth method, together with subsequent calcination, was applied to introduce SnO₂ shells and remove poly(ethyleneglycol dimethacrylate-co-methacrylic acid) shells, which led to the successful preparation of innovative core-shell Fe₃O₄@SnO₂ nanochains. The unique microstructure and appropriate components endowed nanochains with multiple functional applications. The minimum reflection loss value was approximately -39.4 dB (5.67 GHz), exhibiting excellent microwave absorption performance. The possible microwave absorption mechanisms involve interfacial polarisation, space charge polarisation, natural resonance, and multiple reflections and scatterings. The optimal infrared reflectivity reached 0.64, 0.51, and 0.37 in three atmospheric windows, indicating outstanding infrared stealth performance, which was attributed to the intense infrared reflection of SnO₂ shells. Furthermore, three nanochains showed different colours (dark green, brick red, and bright orange), revealing selection absorption for visible light. This can be attributed to the combined effect of visible responses of SnO₂ shells along with Bragg diffraction from the periodic arrangement of Fe₃O₄ particles in a single nanochain. Thus, core-shell Fe₃O₄@SnO₂ nanochains can be considered as promising radar-infrared-visible compatible stealth materials. This discovery opens a new means to exploit multiband-compatible stealth materials.

Saad G. Induction of mitochondria mediated apoptosis in human ovarian cancer cells by folic acid coated tin oxide nanoparticles

PURPOSE

This study aims to prepare folic acid coated tin oxide nanoparticles (FA-SnO2 NPs) for specifically targeting human ovarian cancer cells with minimum side effects against normal cells.

METHODS

The prepared FA-SnO2 NPs were characterized by FT-IR, UV-vis spectroscopy, XRD, SEM and TEM. The inhibition effects of FA-SnO2 NPs against SKOV3 cancer cell were tested by MTT and LDH assay. Apoptosis induction in FA-SnO2 NPs treated SKOV3 cells were investigated using Annexin V/PI, AO/EB and Comet assays and the possible mechanisms of the cytotoxic action were studied by Flow cytometry, qRT-PCR, Immunohistochemistry, and Western blotting analyses. The effects of FA-SnO2 NPs on reactive oxygen species generation in SKOV3 cells were also examined. Additionally, the safety of utilization FA-SnO2 NPs were studied in vivo using Wister rats.

RESULTS

The obtained FA-SnO2 NPs displayed amorphous spherical morphology with an average diameter of 157 nm and a zeta potential value of -24 mV. Comparing to uncoated SnO2 NPs, FA-SnO2 NPs had a superior inhibition effect towards SKOV3 cell growth that was suggested to be mediated through higher reactive oxygen species generation. It was showed that FA-SnO2 NPs increased significantly the % of apoptotic cells in the sub- G1 and G2/M phases with a higher intensity comet nucleus in SKOV3 treated cells. Furthermore, FA-SnO2 NPs was significantly increased the expression levels of P53, Bax, and cleaved Caspase-3 and accompanied with a significant decrease of Bcl-2 in the treated SKOV3 cells.

CONCLUSION

Overall, the results suggested that an increase in cellular FA-SnO2 NPs internalization resulted in a significant induced cytotoxicity in SKOV3 cancer cells in dose-dependent mode through ROS-mediated cell apoptosis that may have occurred through mitochondrial pathway. Additionally, the results confirmed the safety of utilization FA-SnO2 NPs against living systems. So, FA-SnO2 NPs with a specific targeting moiety may be a promising therapeutic candidate for human ovarian cancer.

Differential response of immobile (pneumocytes) and mobile (monocytes) barriers against 2 types of metal oxide nanoparticles

BACKGROUND

Inhaled nanoparticles (NPs) challenges mobile and immobile barriers in the respiratory tract, which can be represented by type II pneumocytes (immobile) and monocytes (mobile) but what is more important for biological effects, the cell linage, or the type of nanoparticle? Here, we addressed these questions and we demonstrated that the type of NPs exerts a higher influence on biological effects, but cell linages also respond differently against similar type of NPs.

DESIGN

Type II pneumocytes and monocytes were exposed to tin dioxide (SnO₂) NPs and titanium dioxide (TiO₂) NPs (1, 10 and 50 μg/cm²) for 24 h and cell viability, ultrastructure, cell granularity, molecular spectra of lipids, proteins and nucleic acids and cytoskeleton architecture were evaluated.

RESULTS

SnO₂ NPs and TiO₂ NPs are metal oxides with similar physicochemical properties. However, in the absence of cytotoxicity, SnO₂ NPs uptake was low in monocytes and higher in type II pneumocytes, while TiO₂ NPs were highly internalized by both types of cells. Monocytes exposed to both types of NPs displayed higher number of alterations in the molecular patterns of proteins and nuclei acids analyzed by Fourier-transform infrared spectroscopy (FTIR) than type II pneumocytes. In addition, cells exposed to TiO₂ NPs showed more displacements in FTIR spectra of biomolecules than cells exposed to SnO₂ NPs. Regarding cell architecture, microtubules were stable in type II pneumocytes exposed to both types of NPs but actin filaments displayed a higher number of alterations in type II pneumocytes and monocytes exposed to SnO₂ NPs and TiO₂ NPs. NPs exposure induced the formation of large vacuoles only in monocytes, which were not seen in type II pneumocytes.

CONCLUSIONS

Most of the cellular effects are influenced by the NPs exposure rather than by the cell type. However, mobile, and immobile barriers in the respiratory tract displayed differential response against SnO₂ NPs and TiO₂ NPs in absence of cytotoxicity, in which monocytes were more susceptible than type II pneumocytes to NPs exposure.

Green and Cost-Effective Synthesis of Tin Oxide Nanoparticles: A Review on the Synthesis Methodologies, Mechanism of Formation, and Their Potential Applications

Nanotechnology has become the most promising area of research with its momentous application in all fields of science. In recent years, tin oxide has received tremendous attention due to its fascinating properties, which have been improved with the synthesis of this material in the nanometer range. Numerous physical and chemical methods are being used these days to produce tin oxide nanoparticles. However, these methods are expensive, require high energy, and also utilize various toxic chemicals during the synthesis. The increased concerns related to human health and environmental impact have led to the development of a cost-effective and environmentally benign process for its production. Recently, tin oxide nanoparticles have been successfully synthesized by green methods using different biological entities such as plant extract, bacteria, and natural biomolecules. However, industrial-scale production using green synthesis approaches remains a challenge due to the complexity of the biological substrates that poses a difficulty to the elucidations of the reactions and mechanism of formations that occur during the synthesis. Hence, the present review summarizes the different sources of biological entities and methodologies used for the green synthesis of tin oxide nanoparticles and the impact on their properties. This work also describes the advances in the understanding of the mechanism of formation reported in the literature and the different analytical techniques used for characterizing these nanoparticles.

Strong and nonspecific synergistic antibacterial/antibiofilm impact of nano-silver biosynthesized and decorated with active ingredients of Oscimum basilicum L

In this study, Ocimum basilicum (a proven broad spectrum medicinal plant for broad-spectrum pharmacological activities) leaf extract was used as conjugates for the fabrication of silver nanoparticles (AgNP). Color change of the reaction mixture and UV-Visible spectrophotometry indicated the fabrication of silver nanoparticles, further X-ray diffraction (XRD) crystallography, scanning electron microscopy (SEM), transmission electron microscopic images (TEM), and Selected area electron diffraction (SAED) confirms the purity, monodispersity, and morphology including size (22.4 nm) and conjugated functional group of Ocimum basilicum. The conjugation of functional OH, N-O, and C=O groups was confirmed by Fourier-transform infrared spectroscopy (FT-IR). The engineered AgNP have shown significantly efficient antibacterial and antibiofilm activities (92.7% biofilm inhibition) on diverse clinical strains and thus showed its potential for use in clinical applications.

Bi/SnO2/TiO2-graphene nanocomposite photocatalyst for solar visible light-induced photodegradation of pentachlorophenol

In this study, for the first time, a TiO₂/graphene (G) heterostructure was synthesized and doped by Bi and SnO₂ nanoparticles through a hydrothermal treatment. The as-synthesized nanocomposite was employed for photocatalytic degradation of pentachlorophenol (PCP) under visible light irradiation. Structural characterizations such as X-ray photoelectron spectroscopy (XPS) and X-ray diffraction spectroscopy (XRD) proved the valence band alignment at Bi/SnO₂/TiO₂-G interfaces and crystallinity of the nanocomposite, respectively. The as-developed nanocomposite photocatalyst was able to decompose 84% PCP, thanks to the generation of a large number of active OH^•- and O₂^•- radicals. To achieve this optimum photodegradation efficiency, various parameters such as pH, catalyst dosage, and PCP concentration were optimized. The results showed that the PCP photodegradation process followed the first-order kinetic model and the reaction rate constant rose from 0.007 min^-1 (Bi) to 0.0149 min^-1 (Bi/SnO₂/TiO₂-G). The PCP photodegradation efficiency did not decrease significantly after 5 cycles, and the nanocomposite photocatalyst still showed a high efficiency of 68% in the last cycle. The excellent photocatalytic activity of Bi/SnO₂/TiO₂-G is ascribed as well as the heterostructure of the nanocomposite photocatalyst.

Synthesis and characterization of SnO2 NPs for photodegradation of eriochrome black-T using response surface methodology

The domestic and industrial sewage contains an extensive range of various organic compounds. Due to the toxicity of these materials, their degradation is considered one of the great environmental challenges. To address this problem, SnO₂ nanoparticles (NPs) were synthesized via a green route, and they were used as an efficient catalyst for the degradation of an organic dye. In the stage of synthesis of nanoparticles, Thymus vulgaris L. extract acted as an efficient capping agent and renewable reducing agent, and SnO₂ NPs were synthesized without addition of any hazardous surfactants. The successful synthesis of SnO₂ NPs was confirmed by XRD, FT-IR, SEM, EDX, and TEM. The photocatalytic performance of SnO₂ NPs was examined for the degradation of eriochrome black-T (ECBT) as a toxic organic dye in aqueous medium under ultraviolet irradiation. Furthermore, the response surface methodology (RSM) with central composite design (CCD) model was carried out to study of the effects of three different operational parameters on degradation of ECBT. In this design, initial pH of solution (3-11), reaction time (0.5-4 h), and the catalyst loading (0.05-0.12 g) were selected as three factors, whereas the degradation efficiency was chosen as the response. The results of the experimental design indicated that initial pH and catalyst loading were highly significant factors, whereas the reaction time was less important than other factors. Also, recyclability of catalyst was investigated, and the obtained results showed that SnO₂ NPs could be easily recovered and reused for at least 4 cycles without any significant decrease in their activity.

Rational Design of Azastatin as a Potential ADC Payload with Reduced Bystander Killing

Auristatins are a class of ultrapotent microtubule inhibitors, whose growing clinical popularity in oncology is based upon their use as payloads in antibody-drug conjugates (ADCs). The most widely utilized auristatin, MMAE, has however been shown to cause apoptosis in non-pathological cells proximal to the tumour ("bystander killing"). Herein, we introduce azastatins, a new class of auristatin derivatives encompassing a side chain amine for antibody conjugation. The synthesis of Cbz-azastatin methyl ester, which included the C2-elongation and diastereoselective reduction of two proteinogenic amino acids as key transformations, was accomplished in 22 steps and 0.76 % overall yield. While Cbz-protected azastatin methyl ester (0.13-3.0 nM) inhibited proliferation more potently than MMAE (0.47-6.5 nM), removal of the Cbz-group yielded dramatically increased IC50 -values (9.8-170 nM). We attribute the reduced apparent cytotoxicity of the deprotected azastatin methyl esters to a lack of membrane permeability. These results clearly establish the azastatins as a novel class of cytotoxic payloads ideally suited for use in next-generation ADC development.

Overview of the Anticancer Potential of the "King of Spices" Piper nigrum and Its Main Constituent Piperine

The main limits of current anticancer therapy are relapses, chemoresistance, and toxic effects resulting from its poor selectivity towards cancer cells that severely impair a patient's quality of life. Therefore, the discovery of new anticancer drugs remains an urgent challenge. Natural products represent an excellent opportunity due to their ability to target heterogenous populations of cancer cells and regulate several key pathways involved in cancer development, and their favorable toxicological profile. Piper nigrum is one of the most popular spices in the world, with growing fame as a source of bioactive molecules with pharmacological properties. The present review aims to provide a comprehensive overview of the anticancer potential of Piper nigrum and its major active constituents-not limited to the well-known piperine-whose undeniable anticancer properties have been reported for different cancer cell lines and animal models. Moreover, the chemosensitizing effects of Piper nigrum in association with traditional anticancer drugs are depicted and its toxicological profile is outlined. Despite the promising results, human studies are missing, which are crucial for supporting the efficacy and safety of Piper nigrum and its single components in cancer patients.

Hydrothermal method-based synthesized tin oxide nanoparticles: Albumin binding and antiproliferative activity against K562 cells

The interaction of nanoparticles with protein and cells may provide important information regarding their biomedical implementations. Herein, after synthesis of tin oxide (SnO₂) nanoparticles by hydrothermal method, their interaction with human serum albumin (HSA) was evaluated by multispectroscopic and molecular docking (MD) approaches. Furthermore, the selective antiproliferative impact of SnO₂ nanoparticles against leukemia K562 cells was assessed by different cellular assays, whereas lymphocytes were used as control cells. TEM, DLS, zeta potential and XRD techniques showed that crystalline SnO₂ nanoparticles have a size of less than 50 nm with a good colloidal stability. Fluorescence and CD spectroscopy analysis indicated that the HSA undergoes some slight conformational changes after interaction with SnO₂ nanoparticles, whereas the secondary structure of HSA remains intact. Moreover, MD outcomes revealed that the charged residues of HSA preferentially bind to SnO₂ nanoclusters in the binding pocket. Antiproliferative examinations displayed that SnO₂ nanoparticles can selectively cause the mortality of K562 cells through induction of cell membrane leakage, activation of caspase-9, -8, -3, down regulation of Bcl-2 mRNA, the elevation of ROS level, S phase arrest, and apoptosis. In conclusion, this data may indicate that SnO₂ nanoparticles can be used as promising particles to be integrated into therapeutic platforms.

Stannic Oxide Nanoparticle Regulates Proliferation, Invasion, Apoptosis, and Oxidative Stress of Oral Cancer Cells

Objective

To explore the effects of SnO₂ nanoparticles (NPs) on proliferation, invasion, apoptosis, and oxidative stress of oral cancer.

Methods

SnO₂ NPs were prepared and characterized. Oral cancer cell lines CAL-27 and SCC-9 were cultured in vitro. We detected the effects of various concentrations of SnO₂ NPs (0, 5, 25, 50, 100, 200 μg/mL) on the proliferation of oral cancer cells, and observed the morphological changes, and measured the cells ability of migration, invasion and apoptosis condition, and the levels of oxidative stress were measured by detecting malondialdehyde (MDA) and reactive oxygen species (ROS). Besides, we also measured the changes of mRNA and protein levels of factors related to cell proliferation, migration, invasion, apoptosis, and oxidative stress.

Results

SnO₂ NPs inhibited the proliferation of oral cancer cells in a concentration-dependent manner (all P < 0.05). And SnO₂ NPs treatment could reduce the migration and invasion ability of cells (all P < 0.05), induce apoptosis, and those effects were better when treated for 48 h than 24 h (all P < 0.05). And SnO₂ NPs could induce oxidative stress in cells (all P < 0.05). Besides, the concentrations of cyclin-D1, C-myc, matrix MMP-9, and MMP-2 in SnO₂ NPs treated group was decreased (all P < 0.05), and the expression levels of cleaved Caspase-3, cleaved Caspase-9, and Cytochrome C were increased (all P < 0.05).

Conclusion

In the present study, we found that SnO₂ NPs could play a cytotoxic role in oral cancer cells, and inhibit cell proliferation, migration, and invasion, and induce oxidative stress and apoptosis, which suggests that SnO₂ NPs may have the effects of anti-oral cancer. However, a more in-depth study is needed to determine its roles.

Effect of Ag-doping on cytotoxicity of SnO2 nanoparticles in tobacco cell cultures

SnO2 nanoparticles (NPs) are promising materials for electrochemical, catalytic, and biomedical applications due to their high photosensitivity, suitable stability characteristics, wide band gap energy potential, and low cost. Doping SnO2 NPs with metallic elements such as Ag has been used to improve their efficiency. Despite their commercial importance, the current literature lacks investigations to determine their toxic effects on plant systems. In this study, SnO2 and Ag/SnO2 NPs were synthesized using polymer pyrolysis method and characterized by means of XRD, TEM, SEM, EDX, and DLS techniques. Subsequently, the toxicity of the synthesized NPs on cell viability, cell proliferation, and a number of oxidative stress markers were measured in tobacco cell cultures. SnO2 and Ag/SnO2 NPs were found to be polygonal in shape with the size range of 10-30 nm. Both NPs induced cytotoxicity by reducing the cell viability and cell proliferation in a dose-dependent manner. Furthermore, the generation of H2O2, phenolics, flavonoids, and increased activities of superoxide dismutase (SOD) and peroxidase (POD) were observed. According to the results, Ag-doping played a key role in the induction of toxicity in tobacco cell cultures. The obtained results confirmed that SnO2 and Ag/SnO2 NPs induced cytotoxicity in tobacco cells through oxidative stress.

Facile synthesis of SnO2shell followed by microwave treatment for high environmental stability of Ag nanoparticles

This study describes a new method for passivating Ag nanoparticles (AgNPs) with SnO₂ layer and their further treatment by microwave irradiation. The one-step process of SnO₂ layer formation was carried out by adding sodium stannate to the boiling aqueous AgNPs solution, which resulted in the formation of core@shell Ag@SnO₂ nanoparticles. The coating formation was a tunable process, making it possible to obtain an SnO₂ layer thickness in the range from 2 to 13 nm. The morphology, size, zeta-potential, and optical properties of the Ag@SnO₂NPs were studied. The microwave irradiation significantly improved the environmental resistance of Ag@SnO₂NPs, which remained stable in different biological solutions such as NaCl at 150 mM and 0.1 M, Tris-buffered saline buffer at 0.1 M, and phosphate buffer at pH 5.6, 7.0, and 8.0. Ag@SnO₂NPs after microwave irradiation were also stable at biologically relevant pH values, both highly acidic (1.4) and alkaline (13.2). Moreover, AgNPs covered with a 13 nm-thick SnO₂ layer were resistant to cyanide up to 0.1 wt%. The microwave-treated SnO₂ shell can facilitate the introduction of AgNPs in various solutions and extend their potential application in biological environments by protecting the metal nanostructures from dissolution and aggregation.

This study describes a new method for passivating Ag nanoparticles (AgNPs) with SnO₂ layer and their further treatment by microwave irradiation.

Phytosynthesized metal oxide nanoparticles for pharmaceutical applications

Developments in nanotechnology field, specifically, metal oxide nanoparticles have attracted the attention of researchers due to their unique sensing, electronic, drug delivery, catalysis, optoelectronics, cosmetics, and space applications. Physicochemical methods are used to fabricate nanosized metal oxides; however, drawbacks such as high cost and toxic chemical involvement prevail. Recent researches focus on synthesizing metal oxide nanoparticles through green chemistry which helps in avoiding the involvement of toxic chemicals in the synthesis process. Bacteria, fungi, and plants are the biological sources that are utilized for the green nanoparticle synthesis. Due to drawbacks such as tedious maintenance and the time needed for the nanoparticle formation, plant extracts are widely used in nanoparticle production. In addition, plants are available all over the world and phytosynthesized nanoparticles show comparatively less toxicity towards mammalian cells. Secondary metabolites including flavonoids, terpenoids, and saponins are present in plant extracts, and these are highly responsible for nanoparticle formation and reduction of toxicity. Hence, this article gives an overview of recent developments in the phytosynthesis of metal oxide nanoparticles and their toxic analysis in various cells and animal models. Also, their possible mechanism in normal and cancer cells, pharmaceutical applications, and their efficiency in disease treatment are also discussed.

Comparative evaluation of nano and bulk tin dioxide cytotoxicity on dermal fibroblasts by real-time impedance-based and conventional methods

In this study, the possible cellular effects of tin dioxide (SnO₂) nanoparticles, together with its bulk form, on mouse dermal fibroblasts (DFs) were revealed using in vitro assays. Particle characterizations were carried out with AFM, Braun-Emmet-Teller, and DLS analyses. The cells were treated with nano and bulk SnO₂ at concentrations of 0.1, 1, 10, 50, and 100 μg/mL for 6, 24, and 48 h. At the end of the exposure periods, the morphology, viability, particle uptake, and membrane leakage statuses of the cells were evaluated. Furthermore, real-time monitoring of cell responses was performed by using an impedance-based label-free system. Findings showed that at concentrations of 0.1-10 μg/mL, cells had similar doubling time to that of control cells (20.4 ± 2.6 h), while the doubling time of cells exposed to 100 μg/mL of nano and bulk SnO₂ increased slightly (P ˃ 0.05) to 25.1 ± 3.9 h and 26.2 ± 5.9 h, respectively. The results indicated that DFs exhibited a similar toxicity response to nano and bulk SnO₂; thus, 50 and 100 μg/mL of nano and bulk SnO₂ had mild toxic effects on DFs. In conclusion, this study provides information and insight necessary for the safe use of SnO₂ in medical and consumer products.