Synthesis and characterization of arginine-modified and europium-doped hydroxyapatite nanoparticle and its cell viability

The arginine-modified and europium-doped hydroxyapatite nanoparticles（HAP-Eu） were synthesized by hydrothermal synthesis.The prepared nanoparticles were characterized by transmission electron microscopy（TEM）,X-ray diffractometry（XRD）,Fourier transform infrared（FTIR） and zeta potential analyzer.The cell viability of HAP-Eu was tested by image flow cytometry.The results indicated that HAP-Eu is short column shapes and its size is approximately 100 nm,its zeta potential is about 30.10 mV at pH of 7.5,and shows no cytotoxicity in human epithelial cells and endothelial cells.

Protein adsorption, cell viability and corrosion properties of Ti6Al4V alloy treated by plasma oxidation and anodic oxidation

The hardness,wettability,and electrochemical properties of Ti6Al4V alloy surfaces treated with anodic oxidation and plasma oxidation as well as the viabilities of the different cell lines on the obtained surfaces were investigated.The anodic oxidation was performed for 10 min under 100 V potential,and it resulted in a 0.95μm thick nanoporous anatase-TiO2 structure.On the other hand,plasma oxidation was carried out at 650℃ for 1 h and resulted in a dense rutile-TiO2 structure with a thickness of 1.2μm.While a hardness of HV0.025823 and roughness of^220 nm were obtained by plasma oxidation,those obtained by anodic oxidation were HV0.025512 and^130 nm,respectively.The anodic oxidation process created a more hydrophilic surface with a contact angle of 87.2°.Both oxidation processes produced similar properties in terms of corrosion behavior and showed better resistance than the as-received state in a certain range of potential.Moreover,the surface treatments led to no significant change in the protein adsorption levels,which indicates that the difference in viability between the osteoblast and fibroblast cells was not due to the difference in surface protein adsorption.Given all the factors,the surfaces obtained by anodic oxidation treatment revealed higher cell viability than those obtained by plasma oxidation(p=0.05).

Aspirin inhibits cell viability and mTOR downstream signaling in gastroenteropancreatic and bronchopulmonary neuroendocrine tumor cells

AIM: To investigate the effect of aspirin on neuroendocrine tumor (NET) cell growth and signaling in vitro.

Changes in Growth,Photosynthetic Pigments,Cell Viability,Lipid Peroxidation and Antioxidant Defense System in Two Varieties of Chickpea(Cicer arietinum L.)Subjected to Salinity Stress

Salinity is one of the most severe abiotic stresses for crop production.The present study investigates the salinityinduced modulation in growth indicators,morphology and movement of stomata,photosynthetic pigments,activity of carbonic anhydrase as well as nitrate reductase,and antioxidant systems in two varieties of chickpea(Pusa-BG5023,and Pusa-BGD72).On 20^(th) day of sowing,plants were treated with varying levels of NaCl(0,50,100,150 and 200 mM)followed by sampling on 45 days of sowing.Recorded observations on both the varieties reveal that salt stress leads to a significant decline in growth,dry biomass,leaf area,photosynthetic pigments,protein content,stomatal behavior,cell viability,activity of nitrate reductase and carbonic anhydrase with the rise in the concentration of salt.However,quantitatively these changes were less in Pusa-BG5023 as compared to Pusa-BGD72.Furthermore,salinity-induced oxidative stress enhanced malondialdehyde content,superoxide radicals,foliar proline content,and the enzymatic activities of superoxide dismutase,catalase,and peroxidase.The variety Pusa-BGD72 was found more sensitive than Pusa-BG5023 to salt stress.Out of different graded concentrations(50,100,150 and 200 mM)of sodium chloride,50 mM was least toxic,and 200 mM was most damaging.The differential behavior of these two varieties measured in terms of stomatal behavior,cell viability,photosynthetic pigments,and antioxidant defense system can be used as prospective indicators for selection of chickpea plants for salt tolerance and sensitivity.

Effect of Cold Plasma on Cell Viability and Collagen Synthesis in Cultured Murine Fibroblasts

An argon atmospheric pressure plasma jet was employed to treat L929 murine fibroblasts cultured in vitro.Experimental results showed that,compared with the control cells,the treatment of fibroblasts with 15 s of plasma led to a significant increase of cell viability and collagen synthesis,while the treatment of 25 s plasma resulted in a remarkable decrease.Exploration of related mechanisms suggested that cold plasma could up-regulate Cyclin D1 gene expression and down-regulate p27 gene expression at a low dose,while it could down-regulate Cyclin D1 expression and up-regulate p27 expression at a higher dose,thus altering the cell cycle progression,and then affecting cell viability and collagen synthesis of fibroblasts.

Poly(Butylene Adipate-Co-Terephthalate)and Poly(ε-Caprolactone)and Their Bionanocomposites with Cellulose Nanocrystals:Thermo-Mechanical Properties and Cell Viability Study

Although nanocomposites have recently attracted special interest in the tissue engineering area,due to their potential to reinforce scaffolds for hard tissues applications,a number of variables must be set prior to any clinical application.This manuscript addresses the evaluation of thermo-mechanical properties and of cell proliferation of cellulose nanocrystals(CNC),poly(butylene adipate-co-terephthalate)(PBAT),poly(ε-caprolactone)(PCL)films and their bionanocomposites with 2 wt% of CNC obtained by casting technique.Cellulose nanocrystals extracted from Balsa wood by acid hydrolysis were used as a reinforcing phase in PBAT and PCL matrix films.The films and pure CNC at different concentrations were cultured with osteoblasts MG-63 and the cell proliferation was assessed by AlamarBlue?assay.The thermal-mechanical properties of the films were evaluated by dynamic-mechanical thermal analysis(DMTA).It was found by DMTA that the CNC acted as reinforcing agent.The addition of CNCs in the PBAT and PCL matrices induced higher storage moduli due to the reinforcement effects of CNCs.The cell viability results showed that neat CNC favored osteoblast proliferation and both PBAT and PCL films incorporated with CNC were biocompatible and supported cell proliferation along time.The nature of the polymeric matrix or the presence of CNC practically did not affect the cell proliferation,confirming they have no in vitro toxicity.Such features make cellulose nanocrystals a suitable candidate for the reinforcement of biodegradable scaffolds for tissue engineering and biomedical applications.

Cell viability in the cadmium-stressed cell suspension cultures of tobacco is regulated by extracellular ATP,possibly by a reactive oxygen species-associated mechanism

Cadmium(Cd)is one of the most widespread and toxic heavy metals to plants.Extracellular ATP(exATP)is thought to be an extracellular effector in regulating the physiological responses of plant cells to environmental stresses.However,the function of exATP in Cd-stressed plant cells is much unknown.The present work showed that treating tobacco(Nicotiana tabacum L.cv.Bright Yellow-2)cell-suspension cultures with exogenous CdCl2 reduced the cell viability,exATP level,and Mg content.However,the production of reactive oxygen species(ROS),Cd content,and electrolyte leakage of the cells were enhanced by exogenous CdCl2.When the Cd-induced accumulation of ROS was decreased by the supplement with DMTU(dimethylthiourea,a scavenger of ROS),the Cd-induced increases of the electrolyte leakage and Cd content were alleviated,and the Cd-induced reductions of cell viability were partly rescued,suggesting that Cd-induced reduction of cell viability could be related to the ROS accumulation.Under the condition of Cd stress,when the reduction of exATP level was partly rescued by exogenous ATP(20μM),the increases of ROS production,electrolyte leakage,and Cd content were attenuated,and the reduction of cell viability was also alleviated.These observations indicate that exATP can regulate the cell viability in the Cd–stressed plant cells possibly by an ROS-associated mechanism.

Cell Viability of Byrsonima intermedia A Juss Calli

Byrsonima intermedia A Juss. is a species with pharmacological properties from the Brazilian Cerrado that shows difficulties related to sexual propagation. Research on cell viability may provide useful information for the selection of cells with embryogenic potential during the callus culture, Within this context, our research is aimed at establishing the cell viability of calli from Byrsonima intermedia leaf segments. The calli went through three subculture phases, of 60 days each, in MS medium with 0.09 M sucrose, 0.6% agar, pH 5.8 and 4.52 laM 2,4-D. The calli were stored in dark conditions and samples were collected every 10 days from each subculture for viability tests with fluorescein 3,6-diacetate （FDA） and 2,3,5-triphenyltetrazolium chloride （TTC）. The staining methods allowed quantifying cell viability in each subculture. The best results from the FDA tests were obtained at 21, 25 and 29 days for the first, second and third subcultures respectively, with 53,86%, 61.88% and 53.73% viable cells. Regarding the TTC test, the largest absorbance values were obtained at 21, 27 and 28 days for the first, second and third subcultures respectively. Fluorescence and spectrophotometry analyses were efficient for determination of cell viability during callus cultivation period.

P53 protein expression and cell viability in irradiated peripheral blood mononuclear cells as bioindicators of radiosensitivity

Cellular radiosensitivity is directly correlated with the mechanism of DNA repair, in which p53 protein plays a major role. In this context, this study correlated cell death with p53 expression in lymphocytes irradiated in vitro with different doses of gammaradiation. For this, peripheral blood samples were collected from 10 healthy subjects. Each sample was divided in aliquots and, separately, irradiated with doses of 0,5;2 and 4 Gy. After this, peripheral blood mononuclear cells (PBMCs) were isolated and cultivated during 72 hours in 5% CO2 at 37oC without mitogen stimulation. The expression of p53 protein was evaluated by flow cytometry. In parallel, cell viability was determined by trypan blue staining. Statistical analysis was performed us-ing analysis of variance (ANOVA), differences were considered as statistically significant when p < 0.05. The results showed an increase of p53 expression with the absorbed dose, which was proportional to cell death, suggesting that p53 can be used as bioindicator of individual radiosensitivity.

Inhibition of viability of human retinal microvascular endothelial cells by vialinin A under high glucose condition

AIM:To investigate the effects of vialinin A on viability of human retinal endothelial cells(HRECs)under high glucose condition and its potential mechanism.METHODS:The HRECs were divided into four groups:normal glucose control group(NG,5 mmol/L D-glucose),high glucose group(HG,30 mmol/L D-glucose),HG+1μmol/L vialinin A group,and HG+5μmol/L vialinin A group.The cell viabilities were measured with cell counting kit-8(CCK-8)assay for proliferation,with scratch assay for migration,and tube formation,for evaluation of the impact of vialinin A on cellular behaviour.Real-time PCR and Western blotting were used to determine the expression level of vascular endothelial growth factor(VEGF).RESULTS:The proliferative capacity and migration of HRECs was reduced by 5μmol/L vialinin A in high glucose environment(both P<0.05).Vialinin A also inhibited highglucose-induced tube formation of HRECs.The expression level of VEGF and PI3K in HRECs was also significantly decreased by vialinin A(P<0.05).CONCLUSION:Vialinin A inhibits the cell viability of HRECs.It may serve as a potential target for anti-angiogenic therapy.

A review on cell damage,viability,and functionality during 3D bioprinting

Three-dimensional(3D)bioprinting fabricates 3D functional tissues/organs by accurately depositing the bioink composed of the biological materials and living cells.Even though 3D bioprinting techniques have experienced significant advancement over the past decades,it remains challenging for 3D bioprinting to artificially fabricate functional tissues/organs with high post-printing cell viability and functionality since cells endure various types of stress during the bioprinting process.Generally,cell viability which is affected by several factors including the stress and the environmental factors,such as pH and temperature,is mainly determined by the magnitude and duration of the stress imposed on the cells with poorer cell viability under a higher stress and a longer duration condition.The maintenance of high cell viability especially for those vulnerable cells,such as stem cells which are more sensitive to multiple stresses,is a key initial step to ensure the functionality of the artificial tissues/organs.In addition,maintaining the pluripotency of the cells such as proliferation and differentiation abilities is also essential for the 3D-bioprinted tissues/organs to be similar to native tissues/organs.This review discusses various pathways triggering cell damage and the major factors affecting cell viability during different bioprinting processes,summarizes the studies on cell viabilities and functionalities in different bioprinting processes,and presents several potential approaches to protect cells from injuries to ensure high cell viability and functionality.

Harnessing decellularised extracellular matrix microgels into modular bioinks for extrusion-based bioprinting with good printability and high post-printing cell viability

The printability of bioink and post-printing cell viability is crucial for extrusion-based bioprinting.A proper bioink not only provides mechanical support for structural fidelity,but also serves as suitable three-dimensional(3D)microenvironment for cell encapsulation and protection.In this study,a hydrogel-based composite bioink was developed consisting of gelatin methacryloyl(GelMA)as the continuous phase and decellularised extracellular matrix microgels(DMs)as the discrete phase.A flow-focusing microfluidic system was employed for the fabrication of cell-laden DMs in a high-throughput manner.After gentle mixing of the DMs and GelMA,both rheological characterisations and 3D printing tests showed that the resulting DM-GelMA hydrogel preserved the shear-thinning nature,mechanical properties,and good printability from GelMA.The integration of DMs not only provided an extracellular matrix-like microenvironment for cell encapsulation,but also considerable shear-resistance for high post-printing cell viability.The DM sizes and inner diameters of the 3D printer needles were correlated and optimised for nozzle-based extrusion.Furthermore,a proof-of-concept bioink composedg of RSC96 Schwann cells encapsulated DMs and human umbilical vein endothelial cell-laden GelMA was successfully bioprinted into 3D constructs,resulting in a modular co-culture system with distinct cells/materials distribution.Overall,the modular DM-GelMA bioink provides a springboard for future precision biofabrication and will serve in numerous biomedical applications such as tissue engineering and drug screening.

Effects of Imazethapyr-Based Herbicide Formulation in the Zebrafish (Danio rerio) Hepatocyte Cell Line (ZF-L): Cytotoxicity and Oxidative Stress

Seizures of agrochemical formulations have increased in Brazil and Rio Grande do Sul is among the Brazilian states with the highest number of seizures of these products obtained illicitly. The use of illicit formulations can cause significant harm to agricultural production, the environment, and non-target species. This study evaluated the cytotoxicity and oxidative stress of a seized formulation containing the herbicide imazethapyr (IMZT). Characterization of the herbicide included gas chromatography-mass spectrometry (GC-MS) and thermal analyses (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)). Hemolytic and cytotoxicity assays in ZF-L hepatic cells showed IC50 values of 12.75 µg/mL, 3.01 µg/mL, 2.67 µg/mL, and 1.61 µg/mL for erythrocytes, [3(4,5-dimethyl)-2 bromide-5 diphenyl tetrazolium] (MTT), neutral red (NR), and lactate dehydrogenase (LDH) assays, respectively. The median IC50 of 2.84 µg/mL was used in oxidative stress assays, revealing increased reactive oxygen species (ROS) production, reduced total sulfhydryl content, and decreased superoxide dismutase (SOD) and catalase (CAT) activity. This study is the first to report in vitro oxidative stress induced by IMZT in the ZF-L cell line, emphasizing the importance of in vitro assays for assessing the toxic effects of seized agrochemicals on human health and the environment.

Ammonium affects cell viability to inhibit root growth in Arabidopsis

Ammonium （NH4^＋） is an important form of nitrogen nutrient for most plants, yet is also a stressor for many of them. However, the primary events of NH4^＋ toxicity at the cellular level are still unclear. Here, we showed that NH4^＋ toxicity can induce the root cell death in a temporal pattern which primarily occurs in the cells of root maturation and elongation zones, and then spreads to the ceils in the meristem and root cap. The results from the NH4^＋-hypersensitive mutant hsn1 further confirmed our findings. Taken together,NH4^＋ toxicity inhibits primary root growth by inhibiting cell elongation and division and inducing root cell death.

Effects of Sialic Acid from Edible Bird Nest on Cell Viability Associated with Brain Cognitive Performance in Mice

Background:Edible bird nest(EBN)is a natural food product rich in glycoprotein such as sialic acid,which has been reported to improve brain functions.The EBN is widely consumed due to its higher nutritional contents and antioxidant status;however,an interaction of EBN on brain cell metabolic activity and viability are still unclear.Objective:The objectives of this study were to identify the effect of sialic acid from EBN on the cell viability and to determine the appropriate concentration of sialic acid on cognitive performance in mice.Materials and Methods:The viability of pheochromocytoma and neuroblastoma cell lines were tested using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay.For in vivo study,7-week-old female BALB/c mice were randomly assigned into four treatment groups and were treated with sialic acid for 21 days.At day 22,all mice were tested on cognitive performance by Y-maze test.Results:Treatment concentration of sialic acid extract and sialic acid standard at 60μg/mL(0.6 ppm)increased cell viability and showed no cytotoxicity effects in pheochromocytoma and neuroblastoma cell lines.In addition,an administration of higher dose of sialic acid at 0.6 ppm in animals improved Y-maze test performance,which they showed significantly higher number of entries and time spent in the novel arm.Conclusion:Thus,the current study shows that the sialic acid extract at 0.6 ppm improved brain cognitive performance in mice associated with an increased viability of pheochromocytoma and neuroblastoma cell lines.

A facile,versatile hydrogel bioink for 3D bioprinting benefits long-term subaqueous fidelity,cell viability and proliferation

Both of the long-term fidelity and cell viability of three-dimensional(3D)-bioprinted constructs are essential to precise soft tissue repair.However,the shrinking/swelling behavior of hydrogels brings about inadequate long-term fidelity of constructs,and bioinks containing excessive polymer are detrimental to cell viability.Here,we obtained a facile hydrogel by introducing 1%aldehyde hyaluronic acid(AHA)and 0.375%N-carboxymethyl chitosan(CMC),two polysaccharides with strong water absorption and water retention capacity,into classic gelatin(GEL,5%)–alginate(ALG,1%)ink.This GEL–ALG/CMC/AHA bioink possesses weak temperature dependence due to the Schiff base linkage of CMC/AHA and electrostatic interaction of CMC/ALG.We fabricated integrated constructs through traditional printing at room temperature and in vivo simulation printing at 37C.The printed cell-laden constructs can maintain subaqueous fidelity for 30 days after being reinforced by 3%calcium chloride for only 20 s.Flow cytometry results showed that the cell viability was 91.3861.55%on day 29,and the cells in the proliferation plateau at this time still maintained their dynamic renewal with a DNA replication rate of 6.0661.24%.This work provides a convenient and practical bioink option for 3D bioprinting in precise soft tissue repair.

Ponatinib and gossypol act in synergy to suppress colorectal cancer cells by modulating apoptosis/autophagy crosstalk and inhibiting the FGF19/FGFR4 axis

Objective:To evaluate the efficacy of ponatinib plus gossypol against colorectal cancer HCT-116 and Caco-2 cells.Methods:Cells were treated with ponatinib and/or gossypol at increasing concentrations to evaluate synergistic drug interactions by combination index.Cell viability,FGF19/FGFR4,and apoptotic and autophagic cell death were studied.Results:Ponatinib(1.25-40μM)and gossypol(2.5-80μM)monotherapy inhibited HCT-116 and Caco-2 cell viability in a doseand time-dependent manner.The combination of ponatinib and gossypol at a ratio of 1 to 2 significantly decreased cell viability(P<0.05),with a>2-and>4-fold reduction in IC50,respectively,after 24 h and 48 h,as compared to the IC50 of ponatinib.Lower combined concentrations showed greater synergism(combination index<1)with a higher ponatinib dose reduction index.Moreover,ponatinib plus gossypol induced morphological changes in HCT-116and Caco-2 cells,increased beclin-1 and caspase-3,and decreased FGF19,FGFR4,Bcl-2 and p-Akt as compared to treatment with drugs alone.Conclusions:Gossypol enhances ponatinib's anticancer effects against colorectal cancer cells through antiproliferative,apoptotic,and autophagic mechanisms.This may open the way for the future use of ponatinib at lower doses with gossypol as a potentially safer targeted strategy for colorectal cancer treatment.

Femtosecond Optical Trapping of Cells:Efficiency and Viability

The femtosecond optical trapping capability and the effect of femtosecond laser pulses on cell viability were studied.The maximum lateral velocity at which the particles just failed to be trapped,together with the measured average trapping power,were used to calculate the lateral trapping force(Q-value) .The viability of the cells after femtosecond laser trapping was ascertained by vital staining.Measurement of the Q-values shows that femtosecond optical tweezers are just as effective as continuous wave optical tweezers.The experiments demonstrate that there is a critical limit for exposure time at each corresponding laser power of femtosecond optical tweezers,and femtosecond laser tweezers are safe for optical trapping at low power with short exposure time.

Roles of constitutively secreted extracellular chaperones in neuronal cell repair and regeneration

Protein quality control involves many processes that jointly act to regulate the expression, localization, turnover, and degradation of proteins, and has been highlighted in recent studies as critical to the differentiation of stem cells during regeneration. The roles of constitutively secreted extracellular chaperones in neuronal injury and disease are poorly understood. Extracellular chaperones are multifunctional proteins expressed by many cell types, including those of the nervous system, known to facilitate protein quality control processes. These molecules exert pleiotropic effects and have been implicated as playing important protective roles in a variety of stress conditions, including tissue damage, infections, and local tissue inflammation. This article aims to provide a critical review of what is currently known about the functions of extracellular chaperones in neuronal repair and regeneration and highlight future directions for this important research area. We review what is known of four constitutively secreted extracellular chaperones directly implicated in processes of neuronal damage and repair, including transthyretin, clusterin, α2-macroglobulin, and neuroserpin, and propose that investigation into the effects of these and other extracellular chaperones on neuronal repair and regeneration has the potential to yield valuable new therapies.

Efficacy of Bee Products(Anzer Honey,Pollen and Propolis)in Detection and Healing of Damage Induced by Antidiabetic Drug Vildagliptin/Metformin Hydrochloride in Healthy Human Pancreatic Cells:Cytotoxic,Genotoxic and Biochemical Studies

Background and Objective Although drugs are powerful therapeutic agents,they have a range of side effects.These side effects are sometimes cellular and not clinically noticeable.Vildagliptin/metformin hydrochloride is one of the most widely used oral antidiabetic drugs with two active ingredients.In this study,we investigated its harmful effects on the metabolic activation system in healthy human pancreatic cells“hTERT-HPNE”,and we aimed to improve these harmful effects by natural products.To benefit from the healing effect,we used the unique natural products produced by the bees of the Anzer Plateau in the Eastern Black Sea Region of Turkey.Methods Cytotoxic and genotoxic effects of the drug were investigated by different tests,such as MTT,flow cytometry-apoptosis and comet assays.Anzer honey,pollen and propolis were analyzed by gas chromatography/mass spectrometry(G/C-MS).A total of 19 compounds were detected,constituting 99.9%of the samples.Results The decrease in cell viability at all drug concentrations was statistically significant compared to the negative control(P<0.05).A statistically significant decrease was detected in the apoptosis caused by vildagliptin/metformin hydrochloride with the supplementation of Anzer honey,pollen and propolis in hTERT-HPNE cells(P<0.05).Conclusion This study can contribute to other studies testing the healing properties of natural products against the side effects of oral antidiabetics in human cells.In particular,Anzer honey,pollen and propolis can be used as additional foods to maintain cell viability and improve heal damage and can be evaluated against side effects in other drug studies.