Inverted Fluorescence Microscope Research Articles

Preosteoblast Adhesion and Viability Study of Freeze-Dried Bovine Bone Block Scaffold Coated with Human Umbilical Cord Mesenchymal Stem Cell Secretome.

Combining a three-dimensional scaffold with growth factors before implantation is one method used to increase scaffold bioactivity in bone tissue engineering. The mesenchymal stem cell (MSC)-conditioned medium (CM), called secretome, contains many proteins and growth factors required for tissue repair and growth. This study evaluated the bioactivity of a bovine bone scaffold combined with the secretome of human umbilical cord MSCs (hUC-MSCs) by analyzing MC3T3-E1 cell adhesion and viability on the scaffold. This in vitro laboratory study evaluated the effect of hUC-MSC secretome applied to bovine bone scaffolds processed using various techniques on MC3T3-E1 cell adhesion and viability. The three experimental groups included deproteinized bovine bone mineral-secretome (DBBM-CM), freeze-dried bovine bone-secretome (FDBB-CM), and decellularized FDBB-CM, whereas the control group was treated with DBBM alone. The cell adhesion test was performed using the centrifugation method after 6 and 24 hours, whereas the cell viability test was conducted using the trypan blue exclusion method after 24, 48, and 72 hours. Cell attachment was visualized after 4',6-diamidino-2-phenylindole staining and viewed under inverted fluorescence microscopy. Statistical analyses were performed using one-way analysis of variance, followed by a post hoc test in cases of significant differences. Statistical analyses showed significantly greater adhesion of the preosteoblasts to the FDBB-CM scaffold at 6 hours (p = 0.002). The results of the adhesion test at 24 hours and the viability tests at all observation times showed no significant differences (p > 0.05). This study found that the average MC3T3-E1 cell adhesions and viabilities were highest for the FDBB-CM and DBBM-CM scaffolds. DBBM scaffolds with the secretome had better cell adhesion and viability than those without the secretome. The addition of MSC secretome increased bovine bone scaffold bioactivity especially in DBBM and FDBB scaffolds.

Immunofluorescence Protocol for Characterization of Platelet and Leukocyte Binding in Extracorporeal Membrane Oxygenation (ECMO) Circuits.

The continuous contact between blood and the foreign surface of the extracorporeal membrane oxygenation (ECMO) circuit contributes to hemostatic, inflammatory, and other physiological disturbances observed during ECMO. Although previous studies have extensively investigated blood samples from patients on ECMO, cell adsorption to the ECMO circuit as an additional factor that could potentially influence clinical outcomes, has largely been overlooked. Here we provide a detailed immunofluorescence (IF) protocol designed to characterize cellular binding on ECMO circuits collected from patients. Extracorporeal membrane oxygenation circuits were collected from three pediatric patients and an albumin primed-only ECMO circuit was used as control. Circuit samples from five different sites within each ECMO circuit were collected and processed for the IF protocol. CD14 and CD42a antibodies were used to identify platelets and leukocytes bound to each ECMO circuit sample and images captured using inverted fluorescence microscopy. The protocol enables the comprehensive characterization of platelet and leukocyte binding to ECMO circuits collected from patients, which could in turn extend our knowledge of the characteristics of circuit binding and may provide guidance for improved ECMO circuit design.

Anti-tumor mechanism of total saponins of Paridis Rhizoma on inducing ferroptosis of breast cancer MCF-7 cells

This study aims to investigate the mechanism of total saponins of Paridis Rhizoma in inducing the ferroptosis of MCF-7 cells and provide a theoretical basis for the clinical treatment of breast cancer with total saponins of Paridis Rhizoma. The methyl thiazolyl tetrazolium(MTT) assay was employed to examine the effects of different concentrations of total saponins of Paridis Rhizoma on the proliferation of MCF-7 cells. A phase contrast inverted microscope was used to observe the morphological changes of MCF-7 cells. The colony formation assay was employed to test the colony formation of MCF-7 cells. The lactate dehydrogenase(LDH) release test was conducted to determine the cell membrane integrity of MCF-7 cells. The cell scratch assay was employed to examine the migration of MCF-7 cells. After that, the level of reactive oxygen species(ROS) in MCF-7 cells was observed by an inverted fluorescence microscope, and the content of Fe~(2+) in MCF-7 cells was detected by the corresponding kit. Transmission electron microscopy was employed to observe the mitochondrial ultrastructure of MCF-7 cells. Western blot was employed to determine the expression of ferroptosis-related proteins, such as p53, solute carrier family 7 member 11(SLC7A11), glutathione peroxidase 4(GPX4), acyl-CoA synthetase long-chain family member 4(ACSL4), and transferrin receptor protein 1(TFR1) in MCF-7 cells. The results showed that 1.5, 3, 4.5, 6, 7.5, and 9 μg·mL~(-1) total saponins of Paridis Rhizoma significantly inhibited the proliferation of MCF-7 cells, with the IC_(50) of 4.12 μg·mL~(-1). Total saponins of Paridis Rhizoma significantly damaged the morphology of MCF-7 cells, leading to the formation of vacuoles and the gradual shrinkage and detachment of cells. Meanwhile, total saponins of Paridis Rhizoma inhibited the colony formation of MCF-7 cells, destroyed the cell membrane(leading to the release of LDH), and shortened the migration distance of MCF-7 cells. Total saponins of Paridis Rhizoma treatment significantly increased the content of ROS, induced oxidative damage, and led to the accumulation of Fe~(2+) in MCF-7 cells. Furthermore, total saponins of Paridis Rhizoma changed the mitochondrial structure, increased the mitochondrial membrane density, led to the decrease or even disappear of ridges, promoted the expression of p53 protein, down-regulated the expression of SLC7A11 and GPX4, and up-regulated the expression of ACSL4 and TFR1. In summary, total saponins of Paridis Rhizoma can significantly inhibit the proliferation and migration of MCF-7 cells and destroy the cell structure by inducing ferroptosis.

Improved stability and antibacterial activity of cinnamaldehyde emulsion co-stabilized by cyclodextrin glycosyltransferase-catalyzed starch products and Tween 80

Cinnamaldehyde, a yellowish essential oil, has potential applications because of its antibacterial ability but is limited by its instability. In this study, we prepared the microencapsulated cinnamaldehyde emulsion co-stabilized by cyclodextrin glycosyltransferase-catalyzed (CGTase-catalyzed) starch products and Tween 80. Microscopic structure analysis by transmission electron microscopy, inverted fluorescence microscopy, and size distribution determination revealed that additional CGTase-catalyzed starch products could increase their homogeneity and decrease their particle sizes by 67.8%. Fluorescence spectra analysis showed the interactions between cinnamaldehyde and the wall materials with a decrease of 29.2% in fluorescence intensity. The cinnamaldehyde emulsion had good temperature, ionic strength, pH, and storage stability. Time-kill curve and inhibition zone showed increased antibacterial activity. Mechanism analysis by thermal gravimetric analysis and differential scanning calorimetry showed that the emulsion had a dual structure of gel network and cyclodextrin inclusion, contributing to its stability. This study could give new insights into the cinnamaldehyde emulsion and provide a good guidance for its application.

Photodynamic effect of vascular-targeted polyphenol nanoparticles on Endothelial cells

BackgroundPort wine stains (PWS) are vascular malformations, and photodynamic therapy (PDT) is a promising treatment. Emerging drug delivery methods employ nanoparticles (NPs) to enhance drug permeability and retention in diseased blood vessels and improve drug bioavailability. (-) -epigallocatechin-3-gallate glycine (EGCG) has anti-angiogenetic effects and boosts photodynamic therapy. Chlorin e6 (Ce6) is capable of efficiently producing singlet oxygen, rendering it a very promising photosensitizer for utilization in nanomedicine. Material and MethodsEGCG-Ce6-NPs were synthesized and characterized using various techniques. The photodynamic effects of EGCG-Ce6-NPs on endothelial cells were evaluated. The compatibility and toxicity of the nanoparticle was tested using the CCK-8 assay. The intracellular uptake of the nanoparticle was observed using an inverted fluorescence microscope, and the intracellular fluorescence intensity was detected using flow cytometry. The ROS generation and apoptosis induced by EGCG-Ce6-NPs was observed using confocal laser scanning microscopy and flow cytometry respectively. ResultsEGCG-Ce6-NPs exhibited stability, spherical shape of uniform size while reducing the particle diameter, low polydisperse profile and retaining the ability to effectively generate singlet oxygen. These characteristics suggest promising potential for enhancing drug permeability and retention. Additionally, EGCG-Ce6-NPs demonstrated good compatibility with endothelial cells and enhanced intracellular uptake of Ce6. Furthermore, EGCG-Ce6-NPs increased activation efficiency, induced significant toxicity, more reactive oxygen species, and a higher rate of late apoptosis after laser irradiation. ConclusionThis in vitro study showed the potentials EGCG-Ce6-NPs for the destruction of endothelial cells in vasculature.

Coaxial 3D Bioprinting Process Research and Performance Tests on Vascular Scaffolds.

Three-dimensionally printed vascularized tissue, which is suitable for treating human cardiovascular diseases, should possess excellent biocompatibility, mechanical performance, and the structure of complex vascular networks. In this paper, we propose a method for fabricating vascularized tissue based on coaxial 3D bioprinting technology combined with the mold method. Sodium alginate (SA) solution was chosen as the bioink material, while the cross-linking agent was a calcium chloride (CaCl2) solution. To obtain the optimal parameters for the fabrication of vascular scaffolds, we first formulated theoretical models of a coaxial jet and a vascular network. Subsequently, we conducted a simulation analysis to obtain preliminary process parameters. Based on the aforementioned research, experiments of vascular scaffold fabrication based on the coaxial jet model and experiments of vascular network fabrication were carried out. Finally, we optimized various parameters, such as the flow rate of internal and external solutions, bioink concentration, and cross-linking agent concentration. The performance tests showed that the fabricated vascular scaffolds had levels of satisfactory degradability, water absorption, and mechanical properties that meet the requirements for practical applications. Cellular experiments with stained samples demonstrated satisfactory proliferation of human umbilical vein endothelial cells (HUVECs) within the vascular scaffold over a seven-day period, observed under a fluorescent inverted microscope. The cells showed good biocompatibility with the vascular scaffold. The above results indicate that the fabricated vascular structure initially meet the requirements of vascular scaffolds.

The role and mechanism of the zinc finger gene ZNF580 in foam cell formation

Coronary atherosclerotic heart disease is an important threat to human health. The pathological basis is atherosclerosis, and foam cell formation is the key link in the initiation of atherosclerosis. Here, foam cell models were established using 50 ng/ml oxidized low-density lipoprotein (ox-LDL) to stimulate in vitro cultures of THP-1 cells for 72 h. The expression of ZNF580, a Cys2–His2 (C2H2) zinc finger protein containing 172 amino acids that was originally cloned by screening a human aortic cDNA library, was measured in foam cells, and its interaction with various regulatory factors during foam cell formation was investigated. Oil red O (ORO) staining was used to observe cell morphology and intracellular lipid levels. Lentivirus transfection was used to induce high ZNF580 expression (Ad-ZNF580) and low ZNF580 expression (Si-ZNF580) in THP-1 cells, and a fluorescent inverted microscope was used to observe the distribution of ZNF580 immunofluorescence to deduce the transfection rate. RNA and total protein were extracted, and the expression levels of ZNF580, cluster of differentiation 36 (CD36), peroxisome proliferator activated receptor-γ (PPAR-γ), ATP-binding cassette transporter A1 (ABCA1) and apolipoprotein E (ApoE) were measured by real-time quantitative PCR. The protein levels were examined by western blotting to evaluate the interaction between ZNF580 and associated regulatory factors. ZNF580 can significantly increase the expression levels of ApoE and ABCA1 and significantly decrease the expression levels of CD36 and PPAR-γ, suggesting that ZNF580-mediated inhibition of foam cell formation is associated with the PPAR-γ-CD36 signalling pathway. Based on these findings, ZNF580 might be a potential therapeutic candidate for the treatment of coronary atherosclerotic heart disease. Zhangzhongbai: ZNF580 inhibit foam cell formation

Studying the Effects and Competitive Mechanisms of YOYO-1 on the Binding Characteristics of DOX and DNA Molecules Based on Surface-Enhanced Raman Spectroscopy and Molecular Docking Techniques.

Revealing the interaction mechanisms between anticancer drugs and target DNA molecules at the single-molecule level is a hot research topic in the interdisciplinary fields of biophysical chemistry and pharmaceutical engineering. When fluorescence imaging technology is employed to carry out this kind of research, a knotty problem due to fluorescent dye molecules and drug molecules acting on a DNA molecule simultaneously is encountered. In this paper, based on self-made novel solid active substrates NpAA/(ZnO-ZnCl2)/AuNPs, we use a surface-enhanced Raman spectroscopy method, inverted fluorescence microscope technology, and a molecular docking method to investigate the action of the fluorescent dye YOYO-1 and the drug DOX on calf thymus DNA (ctDNA) molecules and the influencing effects and competitive relationships of YOYO-1 on the binding properties of the ctDNA-DOX complex. The interaction sites and modes of action between the YOYO-1 and the ctDNA-DOX complex are systematically examined, and the DOX with the ctDNA-YOYO-1 are compared, and the impact of YOYO-1 on the stability of the ctDNA-DOX complex and the competitive mechanism between DOX and YOYO-1 acting with DNA molecules are elucidated. This study has helpful experimental guidance and a theoretical foundation to expound the mechanism of interaction between drugs and biomolecules at the single-molecule level.

Effects of stress-induced protein Sestrin2 on necroptosis of dendritic cells induced by lipopolysaccharide

To investigate the effect of stress-induced protein Sestrin2 (SESN2) on necroptosis of mouse dendritic cell (DC) induced by lipopolysaccharide (LPS) combined with zVAD, a panaspartate-specific cysteine protease (caspase) inhibitor. The DC2.4 cell line derived from the bone marrow of mouse in the 3rd to 10th generations was cultured. The cells were stimulated with LPS for 0 hour, 6 hours, 12 hours, and 24 hours, and grouped according to the stimulation time points. Western blotting was performed to determine the protein expression of SESN2 in each group. Overexpression empty lentivirus (NC), SESN2 gene overexpression RNA sequence lentivirus (SESN2 LV-RNA), small interfering empty lentivirus (NS), and SESN2 gene small interfering RNA sequence lentivirus (SESN2 siRNA) were transfected into DC2.4 cells. After 72 hours of transfection, cell fluorescence expression was observed under the inverted fluorescence microscope. Cells in each transfection group were stimulated with LPS for 24 hours. The blank control groups were set up and cultured with phosphate buffered saline (PBS) for 24 hours. Western blotting was performed to measure SESN2 protein expression. In the same groups as above, cells were stimulated with LPS+zVAD for 24 hours. The blank control groups were set up and cultured with PBS for 24 hours. Western blotting was used to determine the expression of mixed lineage kinase domain-like protein (MLKL) and phosphorylated-MLKL (p-MLKL). The p-MLKL levels and the number of positive cells were observed using laser scanning confocal microscopy. The necroptotic cell ratios were assessed by both flow cytometry and Hoechst staining. Compared to the LPS 0 hour group, the expression of SESN2 in the LPS 24 hours group showed a significant increase. Therefore, 24 hours was chosen as the subsequent stimulation time point. After successful lentivirus transduction and 24 hours of cultivation, the MLKL phosphorylation level in the SESN2 siRNA+LPS+zVAD group was significantly higher than that in the NS+LPS+zVAD group. The MLKL phosphorylation in the SESN2 LV-RNA+LPS+zVAD group was significantly lower than that in the NC+LPS+zVAD group. The MLKL phosphorylation levels in both the NS+LPS+zVAD group and the NC+LPS+zVAD group were obviously higher than those in the NS+PBS group and the NC+PBS group, respectively. Laser scanning confocal microscopy showed that the trends in quantity and fluorescence intensity of p-MLKL protein expressions were consistent with the above results. The results from flow cytometry analysis and Hoechst staining showed that the rates of cell necrotic apoptosis in SESN2 siRNA+LPS+zVAD group were significantly higher than those in NS+LPS+zVAD group [flow cytometry analysis: (30.800±1.153)% vs. (20.800±1.114)%, Hoechst staining: (75.267±0.451)% vs. (46.267±3.371)%, both P < 0.05], indicating that knocking down SESN2 further exacerbated the occurrence of necroptosis. The necrotic apoptosis rates in SESN2 LV-RNA+LPS+zVAD group were significantly lower than those in NC+LPS+zVAD group [flow cytometry analysis: (7.160±0.669)% vs. (19.240±2.322)%, Hoechst staining: (32.433±3.113)% vs. (48.567±4.128)%, both P < 0.05], indicating that overexpressing SESN2 reversed such response and markedly reduced the proportion of necroptotic cells compared to the corresponding empty vector group. SESN2 exhibits an inhibitory effect on necroptosis of DC in sepsis. Targeted SESN2 expression may regulate the process of DC-mediated immune response in sepsis.

Selenium protects against Pb-induced renal oxidative injury in weaning rats and human renal tubular epithelial cells through activating NRF2

BackgroundLead (Pb) poisoning posing a crucial health risk, especially among children, causing devastating damage not only to brain development, but also to kidney function. Thus, an urgent need persists to identify highly effective, safe, and low-toxicity drugs for the treatment of Pb poisoning. The present study focused on exploring the protective effects of Se on Pb-induced nephrotoxicity in weaning rats and human renal tubular epithelial cells, and investigated the possible mechanisms. MethodsForty weaning rats were randomly divided into four groups in vivo: control, Pb-exposed, Pb+Se and Se. Serum creatinine (Cr), urea nitrogen (BUN) and hematoxylin and eosin (H&E) staining were performed to evaluate renal function. The activities of antioxidant enzymes in the kidney tissue were determined. In vitro experiments were performed using human renal tubular epithelial cells (HK-2 cells). The cytotoxicity of Pb and Se was detected by 3-(4,5-dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Inverted fluorescence microscope was used to investigate cell morphological changes and the fluorescence intensity of reactive oxygen species (ROS). The oxidative stress parameters were measured by a multi-detection reader. Nuclear factor-erythroid-2-related factor (NRF2) signaling pathways were measured by Western blot and reverse transcription polymerase chain reaction (RT-PCR) in HK-2 cells. ResultsWe found that Se alleviated Pb-induced kidney injury by relieving oxidative stress and reducing the inflammatory index. Se significantly increased the activity of the antioxidant enzymes glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), whereas it decreased the excessive release of malondialdehyde (MDA) in the kidneys of weaning rats and HK-2 cells. Additionally, Se enhanced the antioxidant defense systems via activating the NRF2 transcription factor, thereby promoting the to downstream expression of heme oxygenase 1. Furthermore, genes encoding glutamate-cysteine ligase synthetase catalytic (GCLC), glutamate-cysteine ligase synthetase modifier (GCLM) and NADPH quinone oxidoreductase 1 (NQO1), downstream targets of NRF2, formed a positive feedback loop with NRF2 during oxidative stress responses. The MTT assay results revealed a significant decrease in cell viability with Se treatment, and the cytoprotective role of Se was blocked upon knockdown of NRF2 by small interfering RNA (siRNA). MDA activity results also showed that NRF2 knockdown inhibited the NRF2-dependent transcriptional activity of Se. ConclusionsOur findings demonstrate that Se ameliorated Pb-induced nephrotoxicity by reducing oxidative stress both in vivo and in vitro. The molecular mechanism underlying Se’s action in Pb-induced kidney injury is related to the activation of the NRF2 transcription factor and the activity of antioxidant enzymes, ultimately suppressing ROS accumulation.

Comparison of different concentrations of chlorhexidine-iodophor composite solution on human skin fibroblasts.

Chlorhexidine-iodophor (CHX-IP) composite solution is a polymer of chlorhexidine and iodophor produced with new technology, for use in diabetic foot infection. However, the effect of CHX-IP on the growth activity of fibroblasts remains unknown, thus the effects of different concentrations of CHX-IP composite solution on the viability and micromorphology of human skin fibroblasts were studied in vitro cell culture in this study. A cell viability assay was applied to calculate cell viability and an inverted fluorescence microscope was used to observe cell morphology over five days. The results showed that the toxic effect of CHX-IP on fibroblasts was solution concentration-dependent and decreased over time. When the concentration of CHX-IP was 5.0mg/ml, 2.5mg/ml, 0.625mg/ml, 0.15625mg/ml, 0.078125mg/ml or 0mg/ml, the difference of optical density (OD) value on different days was statistically significant (p<0.05). There were statistically significant differences in the OD value of fibroblasts among different concentrations of CHX-IP on: day 2 (F=4.809, p=0.004); day 3 (F=21.508, p<0.001); day 4 (F=63.952, p<0.001); and day 5 (F=160.407, p<0.001). In addition, a concentration of 5.0mg/ml CHX-IP resulted in a fibroblastic viability rate of 0% on day 4, when CHX-IP was diluted to 2.5mg/ml or 1.25 mg/ml, fibroblastic viability rate decreased to 0% day 5. However, when the CHX-IP was diluted to 0.15625mg/ml or 0.078125mg/ml, the fibroblastic cell viability rate increased slightly on day 5. The morphology of cells observed under microscope indirectly supported this result. The findings of this study showed that the toxic effect of CHX-IP on fibroblasts was solution concentration-dependent and decreased over time.

Enhancing the marine antifouling property of high-density polyethylene through melt grafting of poly (hexamethylene guanidine)

Acquiring environment-friendly, wide-spectrum antifouling materials is currently a significant challenge. Herein, we focused on covalently bonding poly (hexamethylene guanidine) (PHMG) to high-density polyethylene (HDPE) through a melt grafting reaction. The successful occurrence of this grafting reaction was confirmed by FT-IR analysis. Moreover, the presence of long-chain branching (LCB) was established through Cole-Cole plot, van Gurp-Palmen diagram, and dynamic thermomechanical property. This presence of LCB improved the impact strength of modified HDPE materials. An increased PHMG grafting content in the material led to a significant increase in the inhibition rate of Escherichia coli and Staphylococcus aureus growth, without any detectable leaching of PHMG. Furthermore, inverted fluorescence microscopy revealed a substantial inhibitory effect of the modified HDPE on diatom attachment and Chlorella sedimentation. Specifically, compared with the unmodified HDPE material, the HDPE with 2 wt% PHMG grafting showed a 79.8% decrease in the attachment rate of diatoms and a 64.5% reduction in Chlorella sedimentation. This research provides valuable insights into the development of eco-friendly antifouling materials with enhanced marine antifouling properties.

Insight into the interaction between ionic nanobubbles and cyanobacteria: Elucidating the role of surfactant and zeta potential in the inactivation of harmful cyanobacteria

Harmful blue-green cyanobacteria, which release cyanotoxins, are a serious threat to water bodies, humans, and the environment worldwide and growing at a significant scale owing to changes in the global climate. In this study, cyanobacteria (Microcystis aeruginosa and Dolichospermum) inactivation was investigated in the presence of different ionic and chitosan-coated nanobubbles (NBs) and the underlying interaction mechanisms between negatively charged cyanobacteria and NBs were evaluated. The characteristics of the generated NBs were examined under different experimental conditions. The characteristics of the cyanobacteria were analyzed using imaging, fluorescence analysis, and absorption spectroscopy. The inactivation of cyanobacteria subjected to different NBs was monitored for 72 h using an ultraviolet–visible spectrophotometer in conjunction with an inverted fluorescence microscope and a scanning electron microscope. The observed inactivation was approximately 90%, and the inactivation of Microcystis aeruginosa was higher than that of Dolichospermum under all the experimental conditions.

Pickering emulsions stabilized by egg white protein-alginate nanoparticles: Freeze-thaw stability after heating

Egg white protein (EWP)-sodium alginate (SA) nanoparticles were fabricated by controlled heating (75 °C, 10 min) of an aqueous solution containing EWP and SA (pH 7.0). The nanoparticles formed had a relatively small average diameter (350–460 nm) and polydispersity index (PDI< 0.3). Hydrogen bonding and electrostatic interactions were the main forces involved in particle formation as determined by Fourier transform infrared spectra and intrinsic fluorescence analyses. The composite nanoparticles had contact angles (θ) of about 90°, which allowed them to be used as particle-based emulsifiers to form and stabilize concentrated oil-in-water Pickering emulsions (70% oil). Inverted fluorescence microscopy showed that the composite nanoparticles adsorbed to the surfaces of the oil droplets in these emulsions. Rheological analysis showed that the Pickering emulsions had predominantly elastic-like properties and exhibited strong shear thinning behavior. The apparent shear viscosity, elastic modulus, and viscous modulus of the emulsions depended on particle size and alginate concentration. A heat treatment (90 °C, 20 min) greatly increased the viscoelastic properties of the emulsions, which was attributed to protein unfolding and aggregation. Heating improved the resistance of the Pickering emulsions to freezing and thawing. This study provides a simple and convenient method to fabricate semi-solid Pickering emulsions using natural ingredients. These emulsions may have a variety of applications in foods, including as edible inks for 3D food printing.

A cellular resolution atlas of Broca's area.

Brain cells are arranged in laminar, nuclear, or columnar structures, spanning a range of scales. Here, we construct a reliable cell census in the frontal lobe of human cerebral cortex at micrometer resolution in a magnetic resonance imaging (MRI)-referenced system using innovative imaging and analysis methodologies. MRI establishes a macroscopic reference coordinate system of laminar and cytoarchitectural boundaries. Cell counting is obtained with a digital stereological approach on the 3D reconstruction at cellular resolution from a custom-made inverted confocal light-sheet fluorescence microscope (LSFM). Mesoscale optical coherence tomography enables the registration of the distorted histological cell typing obtained with LSFM to the MRI-based atlas coordinate system. The outcome is an integrated high-resolution cellular census of Broca's area in a human postmortem specimen, within a whole-brain reference space atlas.

Assessment of developmental rate of mouse embryos yielded from in vitro fertilization of the oocyte with treatment of melatonin and vitamin C simultaneously

BackgroundIn recent decades, in vitro fertilization (IVF) has been widely used as a method of assisted reproductive technology (ART) to improve fertility in individuals. To be more successful in this laboratory method, we used the presence of two common types of antioxidants (melatonin and vitamin C) simultaneously and exclusively in IVF medium.MethodsThe cumulus-oocyte complexes (COCs) were obtained from Gonadotropin-releasing hormone (GnRH) and Human Chorionic Gonadotropin (HMG) -stimulated mice. Subsequently, metaphase II (MII) oocytes were fertilized in vitro. In the experiment, the IVF medium was randomly divided into two equal groups: The control group did not receive any antioxidants. In the treatment group, 100 µM melatonin and 5 mM vitamin C were added to the IVF medium. Finally, oocytes and putative embryos transferred into developmental medium and cultured 120 h after IVF to the blastocyst stage. After and before IVF, oocytes and putative embryos were stained with dichlorodihydrofluorescein diacetate (DCFDA) and the H2O2 level was measured with an inverted fluorescence microscope using ImageJ software. At the end of the fifth day after IVF, the expression of Bax and B cell lymphoma 2 (Bcl2) was evaluated using real-time PCR.ResultsThe levels of reactive oxygen species (ROS) in oocytes and putative embryos observed in the treatment group demonstrated a significant reduce compared to the control group (p ≤ 0.01. (.Furthermore, the number of embryos in the blastocycte stage(P < 0.05), the expression level of the Bcl2 (P < 0.05) gene, the Bax unlike gene, significantly increased compared with the control group.ConclusionWe conclude that the presence of melatonin and vitamin C antioxidants simultaneously and exclusively in the IVF medium leads to a reduction in ROS and ,as a result, improves the growth of the embryo up to the blastocyst stage.

Inhibiting zero-order light of a spatial light modulator with voltage optimization.

The crucial zero-order light due to the pixelation effect of spatial light modulator (SLM) has been a serious issue in the field of light modulation, especially in applications with a high numerical aperture optical system. In this investigation, we report that by properly adjusting the high-level and low-level pixel voltages of an SLM, the zero-order light caused by the pixelation effect of an SLM can be significantly eliminated. The method is further validated under an inverted fluorescence microscope. The experimental results show that the zero-order light can be inhibited up to 91.3%, accompanied by an improvement of the modulation efficiency from 77.5% to 92.6%.

The use of apolipoprotein A-I as a transport form of the green fluorescent protein GFP gene in rat hepatocytes

The aim of this study was to investigate the possibility of using apolipoprotein A-I (apo A-I) as a transport form of the green fluorescent protein (GFP) gene into rat hepatocytes.Material and methods. A culture of isolated rat hepatocytes was used as a model. Apo A-I conjugate with fluorescein isothiocyanate (FITC) was obtained by incubation of apo A-I protein with FITC in carbonate buffer pH 9.5 at a ratio of 12.5 μg FITC per 1 mg of protein. Plasmids for pE-GAG transfection with an integrated GFP gene were enriched in the promoter part with cis-elements of the CC(GCC)3-5 type to enhance complex formation with apo A-I. An inverted fluorescence microscope was used for visual analysis of cell fluorescence.Results and discussion. The paper presents evidence of FITC-labeled apo A-I penetration into the cytoplasm and nuclei of rat hepatocytes by receptor-mediated endocytosis. On this basis, it is proposed an attempt to use apo A-I as a means of targeted delivery of plasmid DNA with an integrated GFP gene into the cell. According to the results of fluorescence microscopy, the use of apo A-I as a plasmid DNA transfection agent led to the accumulation of the GFP protein in the cytoplasm of hepatocytes. No fluorescent protein was observed in the absence of apo A-I.Conclusions. The result obtained may indicate the delivery of the GFP gene to the nuclear apparatus of the cell, its expression and GFP protein synthesis.

Highly sensitive digital detection of SARS-CoV-2 nucleocapsid protein through single-molecule counting.

Nucleocapsid protein (NP) is one of the structural proteins of SARS-CoV-2 which is stable, well-conserved, highly immunogenic, and abundantly expressed due to the host's adaptive immune response, making it a promising antigenic biomarker for the early and rapid identification and diagnosis of SARS-CoV-2. Traditional antigen analytical methods with NP as the detection marker often have insufficient sensitivity. To achieve rapid and highly sensitive detection of NP, we constructed a novel single-molecule (digital) fluorescence-linked immunosorbent assay (FLISA) based on streptavidin-modified transparent 96-well microplates. Streptavidin was immobilized on the microplate under optimized conditions with a 15mM carbonate buffer solution (pH 9.6) as the coating solution, biotinylated antibodies conjugated with streptavidin as capture probes, and carboxylated fluorescent microsphere-conjugated monoclonal antibodies (FMs-mAbs) as fluorescent probes. Individual sandwich immunolabeled complexes of the SARS-CoV-2 diagnostic marker NP were detected and counted though wide-field inverted fluorescence microscopy (1.1 × 1.4 mm2). FLISA had a linear detection range of 0.2pg/mL to 200ng/mL and a limit of detection (LOD) of 0.73fg/mL and 8fg/mL for NP in phosphate buffer saline and spiked nasal swab samples, respectively. The sensitivity was much higher than commercial antigen detection kits, providing wide detection prospects in future clinical diagnosis, environmental monitoring, and other fields.

Calcium Imaging In Electrically Stimulated Flat-Mounted Retinas.

Retinal dystrophies are a leading cause of blindness worldwide. Extensive efforts are underway to develop advanced retinal prostheses that can bypass the impaired light-sensing photoreceptor cells in the degenerated retina, aiming to partially restore vision by inducing visual percepts. One common avenue of investigation involves the design and production of implantable devices with a flexible physical structure, housing a high number of electrodes. This enables the efficient and precise generation of visual percepts. However, with each technological advancement, there arises a need for a reliable and manageable ex vivo method to verify the functionality of the device before progressing to in vivo experiments, where factors beyond the device's performance come into play. This article presents a comprehensive protocol for studying calcium activity in the retinal ganglion cell layer (GCL) following electrical stimulation. Specifically, the following steps are outlined: (1) fluorescently labeling the rat retina using genetically encoded calcium indicators, (2) capturing the fluorescence signal using an inverted fluorescence microscope while applying distinct patterns of electrical stimulation, and (3) extracting and analyzing the calcium traces from individual cells within the GCL. By following this procedure, researchers can efficiently test new stimulation protocols prior to conducting in vivo experiments.