Plate Reader Research Articles

CCPE Fusion Proteins as Molecular Probes to Detect Claudins and Tight Junction Dysregulation in Gastrointestinal Cell Lines, Tissue Explants and Patient-Derived Organoids.

Claudins regulate paracellular permeability, contribute to epithelial polarization and are dysregulated during inflammation and carcinogenesis. Variants of the claudin-binding domain of Clostridium perfringens enterotoxin (cCPE) are highly sensitive protein ligands for generic detection of a broad spectrum of claudins. Here, we investigated the preferential binding of YFP- or GST-cCPE fusion proteins to non-junctional claudin molecules. Plate reader assays, flow cytometry and microscopy were used to assess the binding of YFP- or GST-cCPE to non-junctional claudins in multiple in vitro and ex vivo models of human and rat gastrointestinal epithelia and to monitor formation of a tight junction barrier. Furthermore, YFP-cCPE was used to probe expression, polar localization and dysregulation of claudins in patient-derived organoids generated from gastric dysplasia and gastric cancer. Live-cell imaging and immunocytochemistry revealed cell polarity and presence of tight junctions in glandular organoids (originating from intestinal-type gastric cancer and gastric dysplasia) and, in contrast, a disrupted diffusion barrier for granular organoids (originating from discohesive tumor areas). In sum, we report the use of cCPE fusion proteins as molecular probes to specifically and efficiently detect claudin expression, localization and tight junction dysregulation in cell lines, tissue explants and patient-derived organoids of the gastrointestinal tract.

Fluorescence-based absolute quantification of near-infrared probes in tissue extracts for biodistribution analyses

In recent years, significant progress has been made in the development of fluorescent contrast agents for clinical applications. For the development of a fluorescent probe, it is crucial to evaluate its safety profile, including biodistribution. Specific methods need to be developed for the absolute quantification of fluorescent probes in tissue specimens from animals administered with test compounds in the framework of biodistribution/efficacy/toxicity studies. Here, we describe a new method for the absolute quantification of fluorescent probes in tissue specimens from animals administered with compounds that have absorption and emission wavelength in the Near-Infrared region (600–800 nm). The protocol is based on the standard addition approach in order to minimize the interference of the matrix on the analyte signal causing inaccuracy in the absolute determination of the concentration. The measurement of the fluorescence intensity is done via a microplate reader. The method has been fully validated and applied for the quantification of a fluorescence-guided surgery targeted contrast agent in a Good Laboratory Practice (GLP) biodistribution study. Results clearly demonstrate that this procedure is fully applicable in a preclinical setting and that it overcomes common issues associated with fluorescence signal quantification in tissue extracts.

IL-1RA promotes oral squamous cell carcinoma malignancy through mitochondrial metabolism-mediated EGFR/JNK/SOX2 pathway

BackgroundInterleukin-1 receptor antagonist (IL-1RA), a member of the IL-1 family, has diverse roles in cancer development. However, the role of IL-1RA in oral squamous cell carcinoma (OSCC), in particular the underlying mechanisms, remains to be elucidated.MethodsTumor tissues from OSCC patients were assessed for protein expression by immunohistochemistry. Patient survival was evaluated by Kaplan–Meier curve analysis. Impact of differential IL-1RA expression on cultured OSCC cell lines was assessed in vitro by clonogenic survival, tumorsphere formation, soft agar colony formation, and transwell cell migration and invasion assays. Oxygen consumption rate was measured by Seahorse analyzer or multi-mode plate reader. PCR array was applied to screen human cancer stem cell-related genes, proteome array for phosphorylation status of kinases, and Western blot for protein expression in cultured cells. In vivo tumor growth was investigated by orthotopic xenograft in mice, and protein expression in xenograft tumors assessed by immunohistochemistry.ResultsClinical analysis revealed that elevated IL-1RA expression in OSCC tumor tissues was associated with increased tumor size and cancer stage, and reduced survival in the patient group receiving adjuvant radiotherapy compared to the patient group without adjuvant radiotherapy. In vitro data supported these observations, showing that overexpression of IL-1RA increased OSCC cell growth, migration/invasion abilities, and resistance to ionizing radiation, whereas knockdown of IL-1RA had largely the opposite effects. Additionally, we identified that EGFR/JNK activation and SOX2 expression were modulated by differential IL-1RA expression downstream of mitochondrial metabolism, with application of mitochondrial complex inhibitors suppressing these pathways. Furthermore, in vivo data revealed that treatment with cisplatin or metformin—a mitochondrial complex inhibitor and conventional therapy for type 2 diabetes—reduced IL-1RA-associated xenograft tumor growth as well as EGFR/JNK activation and SOX2 expression. This inhibitory effect was further augmented by combination treatment with cisplatin and metformin.ConclusionsThe current study suggests that IL-1RA promoted OSCC malignancy through mitochondrial metabolism-mediated EGFR/JNK activation and SOX2 expression. Inhibition of this mitochondrial metabolic pathway may present a potential therapeutic strategy in OSCC.

EP4 Receptor Conformation Sensor Suited for Ligand Screening and Imaging of Extracellular Prostaglandins.

Prostaglandins are important lipid mediators with a wide range of functions in the human body. They act mainly via plasma membrane localized prostaglandin receptors, which belong to the G-protein coupled receptor class. Due to their localized formation and short lifetime, it is important to be able to measure the distribution and abundance of prostaglandins in time and/or space. In this study, we present a Foerster resonance energy transfer (FRET)-based conformation sensor of the human prostaglandin E receptor subtype 4 (EP4 receptor), which was capable of detecting prostaglandin E2 (PGE2)-induced receptor activation in the low nanomolar range with a good signal-to-noise ratio. The sensor retained the typical selectivity for PGE2 among arachidonic acid products. Human embryonic kidney cells stably expressing the sensor did not produce detectable amounts of prostaglandins making them suitable for a coculture approach allowing us, over time, to detect prostaglandin formation in Madin-Darby canine kidney cells and primary mouse macrophages. Furthermore, the EP4 receptor sensor proved to be suited to detect experimentally generated PGE2 gradients by means of FRET-microscopy, indicating the potential to measure gradients of PGE2 within tissues. In addition to FRET-based imaging of prostanoid release, the sensor allowed not only for determination of PGE2 concentrations, but also proved to be capable of measuring ligand binding kinetics. The good signal-to-noise ratio at a commercial plate reader and the ability to directly determine ligand efficacy shows the obvious potential of this sensor interest for screening and characterization of novel ligands of the pharmacologically important human EP4 receptor. SIGNIFICANCE STATEMENT: The authors present a biosensor based on the prostaglandin E receptor subtype 4, which is well suited to measure extracellular prostaglandin E2 (PGE2) concentration with high temporal and spatial resolution. It can be used for the imaging of PGE2 levels and gradients by means of Foerster resonance energy transfer microscopy, and for determining PGE2 release of primary cells as well as for screening purposes in a plate reader setting.

Macrophages polarize to the pro-inflammatory phenotype and delay neutrophil efferocytosis to augment Aggregatibacter actinomycetemcomitance JP2 clearance.

The study examines how neutrophils cross-talk with macrophages during JP2 Aggregatibacter actinomycetemcomitance infection and factors that are involved in inflammatory resolution and efferocytosis. Although sub-gingival bacteria constitute the primary initiating factor in the pathogenesis of molar-incisor pattern periodontitis (MIPP), the non-resolved host response has a major role in tissue destruction. While evidence links neutrophils to MIPP pathogenesis, their clearance during inflammatory resolution, governed by macrophages, is poorly understood. Human neutrophils (differentiated from HL60 cells) and macrophages (differentiated from THP1 cells) were inoculated with JP2. The supernatants were collected and exposed to naïve neutrophils or macrophages with or without exposure to JP2. Reactive oxygen species (ROS) were measured with 2'-7'-dichlorofluorescein-diacetate and a fluorescent plate reader. Immunofluorescence labeling of CD47 and cell vitality were examined using flow cytometry. Macrophage polarization was tested by immunofluorescence staining for CD163 and CD68 and a fluorescent microscope, and TNFα and IL-10 secretion was tested using ELISA and RT-PCR. Efferocytosis was examined by pHrodo and carboxyfluorescein succinimidyl ester staining and fluorescent microscopy. In vivo, macrophages were depleted from C57Bl/6 mice and neutrophil CD47 levels were tested using the subcutaneous chamber model. Neutrophils exposed to macrophage supernatant show increased ROS, mainly extracellularly, that increased during JP2 infection. Macrophages showed pro-inflammatory M1 phenotype polarization during JP2 infection, and their supernatants prolonged neutrophil survival by inhibiting CD47 down-expression and reducing neutrophil necrosis and apoptosis. Also, the macrophages delay neutrophil efferocytosis during JP2 infection which, in turn, enhanced JP2 clearance. Depletion of macrophages in mice mildly prevented neutrophils CD47 reduction and reduced JP2 clearance. The JP2 infection in mice also led to macrophage M1 polarization similar to the in vitro results. As shown in this study, neutrophil efferocytosis potentially may be reduced during JP2 infection, promoting JP2 clearance, which may contribute to the inflammatory-mediated periodontal tissue damage.

Construction of Magnetic Core-Large Mesoporous Satellite Immunosensor for Long-Lasting Chemiluminescence and Highly Sensitive Tumor Marker Determination.

Chemiluminescence immunoassay exhibits high sensitivity and signal-to-noise ratio, thus attracting great attention in the early diagnosis and dynamic monitoring of diseases. However, the collection of conventional flash-type chemiluminescence signal (<5s) relies heavily on automatic sampling and reading instrument. Herein, a novel core-satellite multifunctional chemiluminescence immunosensor is designed for the efficient enrichment and highly sensitive determination of cancer biomarker carcinoembryonic antigen (CEA) with enhanced and long-lasting output signal that can be conveniently recorded by a simple microplate plate reading instrument. Anti-CEA monoclonal antibody 2 (Ab2) modified Fe3 O4 @SiO2 microspheres (Fe3 O4 @SiO2 -Ab2, 370nm in diameter) are synthesized as the core for selectively capturing and enriching target CEA in solution, and anti-human CEA monoclonal antibody 1 (Ab1) and horseradish peroxidase (HRP) co-immobilized dendritic large-mesoporous silica nanospheres (MSNs-HRP/Ab1, 80nm in diameter, pore size: 17nm) are synthesized as the satellite for efficient immunological recognition and signal amplification. The as-designed core-satellite magnetic chemiluminescence immunosensors exhibit a broad linear range of 0.01-20ngmL-1 and a low detection limit of 3.0pgmL-1 for the convenient, highly specific, and sensitive determination of CEA in human serum. Such core-satellite chemiluminescence immunosensors are expected to act as a powerful tool for in vitro detection of various biomarkers, overcome the defect of conventional chemiluminescence relying heavily on expensive and bulky automatic instruments and popularize chemiluminescence analysis to primary medical institutions and remote areas.

Bone marrow stromal cell-derived exosome combinate with fibrin on tantalum coating titanium implant accelerates osseointegration.

This study aims to present a sustainably releasing system of exosomes-fibrin combinate loaded on tantalum-coating titanium implants. We hope to investigate potential effects of the system on osseointegration between tantalum coating titanium implants and its surrounding bone tissue. Exosomes derived from rabbit bone marrow stromal cells (rBMSCs) and fibrin were deposited onto the micro-nanostructure tantalum coating surface (Ta + exo + FI) and compared to control groups, including tantalum coating (Ta), tantalum coating loaded exosomes (Ta + exo) and tantalum coating loaded fibrin (Ta + FI). The optimal concentration of loading exosomes, exosomes uptake capacity by BMSCs, and the effect of controlled-release by fibrin were assessed by laser scanning confocal microscope (LCSM) and microplate reader. The optimal concentration of exosomes was 1μg/μL. Adhesion, proliferation, and osteogenic differentiation ability of BMSCs on different materials were assessed in vitro. Finally, osseointegrative capacity of Ta, Ta + exo, Ta + FI, Ta + exo + FI implants in rabbit tibia were respectively evaluated with histology and bone-implant contact ratio (BIC%). It was demonstrated that exosome sustained-release system with fibrin loading on the tantalum coating was successfully established. Fibrin contribute to exosomes release extension from 2d to 6d. Furthermore, Ta + exo + FI significantly promoted adhesion, proliferation, and osteogenic differentiation of BMSCs. In vivo, the implants in Ta + exo + FI group displayed the highest osseointegrative capability than those in other groups. It is concluded that this exosome delivery system on the implants may be an effective way for tantalum coating titanium implants to promote osseointegration between implant and its surrounding bone tissue.

Evaluation of chronic drug-induced electrophysiological and cytotoxic effects using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

Introduction: Cardiotoxicity is one of the leading causes of compound attrition during drug development. Most in vitro screening platforms aim at detecting acute cardio-electrophysiological changes and drug-induced chronic functional alterations are often not studied in the early stage of drug development. Therefore, we developed an assay using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) that evaluates both drug-induced acute and delayed electrophysiological and cytotoxic effects of reference compounds with clinically known cardiac outcomes. Methods: hiPSC-CMs were seeded in 48-well multielectrode array (MEA) plates and were treated with four doses of reference compounds (covering and exceeding clinical free plasma peak concentrations -fCmax values) and MEA recordings were conducted for 4days. Functional-electrophysiological (field-potentials) and viability (impedance) parameters were recorded with a MEA machine. Results: To assess this platform, we tested tyrosine-kinase inhibitors with high-cardiac risk profile (sunitinib, vandetanib and nilotinib) and low-cardiac risk (erlotinib), as well as known classic cardiac toxic drugs (doxorubicin and BMS-986094), ion-channel trafficking inhibitors (pentamidine, probucol and arsenic trioxide) and compounds without known clinical cardiotoxicity (amoxicillin, cetirizine, captopril and aspirin). By evaluating the effects of these compounds on MEA parameters, the assay was mostly able to recapitulate different drug-induced cardiotoxicities, represented by a prolongation of the field potential, changes in beating rate and presence of arrhythmic events in acute (<2h) or delayed phase ≥24h, and/or reduction of impedance during the delayed phase (≥24h). Furthermore, a few reference compounds were tested in hiPSC-CMs using fluorescence- and luminescence-based plate reader assays, confirming the presence or absence of cytotoxic effects, linked to changes of the impedance parameters measured in the MEA assay. Of note, some cardiotoxic effects could not be identified at acute time points (<2h) but were clearly detected after 24h, reinforcing the importance of chronic drug evaluation. Discussion: In conclusion, the evaluation of chronic drug-induced cardiotoxicity using a hiPSC-CMs in vitro assay can contribute to the early de-risking of compounds and help optimize the drug development process.

Sulfhydryl compound levels are associated with ATO-induced side effects in acute promyelocytic leukemia patients

ABSTRACTObjectiveThe remarkable effect of arsenic trioxide (ATO) was verified, but side effects are generally observed in acute promyelocytic leukemia (APL) patients, especially leukocytosis and hepatotoxicity. Our aims are to study predictors and reduce ATO-induced side effects without inhibiting efficacy.MethodsSulfhydryl in ATO-treated APL patients was detected by the Spectra Max M5 microplate reader. And patients were divided into high and low sulfhydryl groups according to median sulfhydryl concentration. The onset time of leukocytosis and the peak value of WBC were compared . Correlations between hepatotoxicity indicators and sulfhydryl concentrations were analysed.ResultsThe concentration of sulfhydryl before treatment was significantly higher in the high sulfhydryl group. Leukocytosis ((7.0 ± 5.5) vs. (14.6 ± 8.5) day) and the peak value of WBC occurred earlier in the low sulfhydryl group ((10.8 ± 5.9) vs. (19.3 ± 5.5) day) than in the high group, and the peak value was significantly lower in the low sulfhydryl group ((24.04 ± 15.05) × 109/L) than in the high group ((42.95 ± 25.57) × 109/L). The elevated liver enzymes were smaller in the higher sulfhydryl group between time points before treatment and the treatment one week later (ΔALT 66.57 vs. 9.85 U/L, ΔAST 59.52 vs. 17.76 U/L), as between time points before treatment and peak value. There was a negative correlation between sulfhydryl and elevated liver enzymes.ConclusionsHigher sulfhydryl compounds contribute to ameliorating ATO-induced leukocytosis and hepatotoxicity in APL patients. The low sulfhydryl before treatment can advance the onset of leukocytosis. For patients with higher sulfhydryl in the early stage, close monitoring of liver enzymes is warranted instead of prophylactic applying any hepatoprotective intervention, to maintain ATO efficacy.

Growth of Bacillus spp. Isolated From Nipah Worm Intestine (Namalycastis rhodochorde) With Different Combination of pH and Salinity

Bacillus spp. (NrLtF1, NrLtF5, and NrLtG2) isolated from the digestive tract of the Nypa palm worm (Namalycastis rhodochorde) were assumed to have growth characteristics according to the habitat conditions of the nypa worm. Nypa worms live in estuary environments that are affected by seawater intrusion. Salinity and pH are two environmental factors affecting gastrointestinal isolates' growth from nypa palm worms. This study aimed to determine the effect of pH and salinity on the media on growth patterns and determine the optimum combination of pH and salinity for Bacillus spp. The study was conducted using a spectrophotometry method using a microplate reader with Glucose Yeast Peptone (GYP) as a medium for bacterial growth. The medium's pH and salinity values were adjusted by adding 5M NaOH and 5M HCl to obtain pH values of 4, 5, 6, and 7, respectively. Addition of NaCl to the growing medium to get salinity values of 5%, 10%, and 15%. Optimization was determined by incubation at a density of 595 nm at a temperature of 31oC for 24 hours. The results showed that Bacillus spp. could grow well at pH 6 with a salinity value of 15%, pH 6 with a salinity value of 10%, and pH 6 with a salinity value of 5% based on contour plot design. The Optimum growth of Bacillus spp. with pH and salinity expects to be a reference for developing feed products based on indigenous nypa palm worms.

Efek ekstrak etanol kelopak bunga rosella (hibiscus sabdariffa l.) Terhadap biofilm prevotella intermedia

Background: The prevalence of periodontal disease in Indonesia reaches 96,58%. Prevotella intermedia is an orange complex bacteria play an important role in periodontitis. One of the therapies for periodontitis disease is the use of antimicrobial mouthwash. Rosella flowers can be used for an alternative therapy for periodontal disease because Rosella flower had been widely used as herbal drink. Purpose: This study aims to find out how rosella flower ethanol extract adheres to prevotella intermedia biofilms. Methods: This research is a laboratory experimental study using the biofilm test method. Rosella flower petals were taken from Balitro in Bogor, West Java. This research was conducted at the FKG Usakti MiCore Laboratory. The ethanol extract of rosella petals was diluted to obtain concentrations of 100%, 50%, 25%, 12.5%, 6.25%, 3.12% and 1.5%. The wellplate was incubated for 1 hour, 6 hours and 24 hours under anaerobic conditions then read the OD (optical density) using a microplate reader at a wavelength of 49nm.Results: The normality test shows normal data distribution (p&gt;0.05). The ANOVA test showed a significant difference (p&gt;0.05). Post-Hoc test showed significant differences between the concentrations of the ethanol extract of rosella calyx. Conclusion: The ethanol extract of rosella calyx has an effect on inhibiting the attachment of the prevotella intermedia biofilm.

Efek ekstrak etanol biji alpukat (persea americana) terhadap biofilm candida albicans

Background: Candida albicans is the most common bacteria related to root canal treatment failure. Avocado seeds (Persea americana) contain terpenoids, alkaloids, flavonoids, steroids, saponins and tannins that have antibacterial activity. Purpose: To determine the effect of avocado seed ethanol extract on C.albicans biofilm. Methods: The effect of avocado seed ethanol extract on C.albicans ATCC 10231 biofilm was evaluated by crystal violet assay. C.albicans were inoculated into Sabouraud Dextrose Broth at 37C for 24 h. A volume of 200 L (108 CFU/mL) C.albicans culture were distributed into 96-well plates and incubated for 24 h. Avocado seed ethanol extract was diluted into 6 concentrations: 100%, 50%, 25%, 12.5%, 6.25% and 3.13% with NaOH 0.1N. NaOCl 5.25% was used as positive control. The extract were added into 96-well plates with C.albicans culture and incubated for 1 h, 3 h and 24 h. The biofilm biomass was calculated by 0,5% crystal violet staining and the optical density value was measured using a microplate reader (490 nm). Results: Ethanol extract of avocado seeds of all concentrations from each incubation period had an antibiofilm against C.albicans when compared to negative control (p &lt; 0.05). The concentration of the extract that has the highest antibiofilm is 6.25% with an incubation period of 24 h which showed an optical density value of 0.011 ± 0.024. Conclusion: Avocado seed ethanol extract has antibiofilm against C.albicans.

Aktivitas Antioksidan Ekstrak Etanol Bunga Clitoria ternatea L. Dengan Senyawa Antioksidan (Antosianin dan Mirisetin)

Background: The COVID-19 pandemic is impacting a large number of populations. Patients with cancer infected with this virus require a longer treatment. Cancer occurs due to oxidative stress which creates an imbalance between the production of reactive oxygen species (ROS) and the amount of antioxidants in the body. Antioxidants are needed to balance ROS and increase the body's resistance to infection and disease. Clitoria ternatea L. is known to be one of the natural ingredients that has the potential as a natural antioxidant. It contains active compounds, such as anthocyanin and myricetin which act as antioxidants. Purpose: To find out the comparison of antioxidant activity C. ternatea L. extract in ethanol 70% solvent with the antioxidant compounds of anthocyanin and myricetin. Method: Research with laboratory experimental methods. C. ternatea L. simplicia was extracted using maceration method in 70% ethanol solvent. Antioxidant activity test using the 2,2-diphenyl-l-picrylhydrazyl (DPPH) method was carried out on samples of C. ternatea L. ethanol extract, anthocyanin and myricetin antioxidant compounds with a wavelength of 517 nm to measure their absorbance using a microplate reader. Result: The IC50 value of the ethanol extract of C. ternatea L. was 52.40 mg/mL, the antioxidant compound anthocyanin was 27.68 mg/mL and the antioxidant compound myricetin was 4.89 mg/mL. Conclusion: The antioxidant compound myricetin has very strong antioxidant activity compared to the ethanol extract of C. ternatea L. and the antioxidant compounds of anthocyanins.

Fluorescence lifetime FRET assay for live-cell high-throughput screening of the cardiac SERCA pump yields multiple classes of small-molecule allosteric modulators

We have used FRET-based biosensors in live cells, in a robust high-throughput screening (HTS) platform, to identify small-molecules that alter the structure and activity of the cardiac sarco/endoplasmic reticulum calcium ATPase (SERCA2a). Our primary aim is to discover drug-like small-molecule activators that improve SERCA’s function for the treatment of heart failure. We have previously demonstrated the use of an intramolecular FRET biosensor, based on human SERCA2a, by screening two different small validation libraries using novel microplate readers that detect the fluorescence lifetime or emission spectrum with high speed, precision, and resolution. Here we report results from FRET-HTS of 50,000 compounds using the same biosensor, with hit compounds functionally evaluated using assays for Ca2+-ATPase activity and Ca2+-transport. We focused on 18 hit compounds, from which we identified eight structurally unique scaffolds and four scaffold classes as SERCA modulators, approximately half of which are activators and half are inhibitors. Five of these compounds were identified as promising SERCA activators, one of which activates Ca2+-transport even more than Ca2+-ATPase activity thus improving SERCA efficiency. While both activators and inhibitors have therapeutic potential, the activators establish the basis for future testing in heart disease models and lead development, toward pharmaceutical therapy for heart failure.

Available calcium levels in central nervous system for Arzenazo III method

The measurement and evaluation of changes in calcium levels between cellular compartments can provide important information for the understanding of biochemical processes, both physiological and pathological. The objective of this study was to validate the use of the calcium diagnostic kit (Arzenazo III) to tissue samples from the Central Nervous System. We used 96-well, flat-bottomed microplates with an internal diameter of 6.7 mm, total height of 12 mm and actual height of 10.705 mm, bottom thickness 1.295 mm, to carry out the tests and calculation parameters, therefore, the path optic was 5.729 mm with a total volume of 202 µL per well. The microplates were incubated at 37 °C for 2 minutes. Optical densities were measured at 630 nm on the Elx800 plate reader, (BioTek, VT, USA). According to the Arzenazo III Bioclin© calcium diagnostic kit. the absorbance of the tests/samples was normalized with the absorbance of the blank (colorimetric reagent 2 - Arsenazo III – Arzenazo III Bioclin© calcium diagnostic kit). PFC, Thalamus and Hippocampus were normalized by blank and presented respectively 0.1782 ± 0.0013; 0.1296 ± 0.0102; 0.0231 ± 0.0053; 0.0170 ± 0.0051; 0.0136 ± 0.0026. The calculation µg calcium / mg tissue obtained 0.4670 ± 0.1056 to sample PFC; 0.4322 ± 0.1228 to sample Thalamus and 0.1027 ± 0.0203 to sample Hippocampus. Although the limitations of the technique, the measurement of free calcium in the CNS tissues (PFC, Thalamus and Hippocampus) showed positive and satisfactory results, as an alternative and viable means for the quantification of calcium levels.

Design and Synthesis of Cabazitaxel Loaded Core-Shell Mesoporous Silica Nanoparticles with Different Morphologies for Prostate Cancer Therapy.

In this work, the synthesis of core-shell ordered mesoporous silica nanoparticles (CSMS) with tunable particle size and shape through a dual surfactant-assisted approach is demonstrated. By varying the synthesis conditions, including the type of the solvent and the concentration of the surfactant, monodispersed and ordered mesoporous silica nanoparticles with tunable particle size (140-600nm) and morphologies (hexagonal prism (HP), oblong, spherical, and hollow-core) can be realized. Comparative studies of the Cabazitaxel (CBZ)-loaded HP and spherical-shaped CSMS are conducted to evaluate their drug delivery efficiency to PC3 (prostate cancer) cell lines. These nanoparticles showed good biocompatibility and displayed a faster drug release at acidic pH than at basic pH. The cellular uptake of CSMS measured using confocal microscopy, flow cytometry, microplate reader, and ICP-MS (inductively coupled plasma mass spectrometry) techniques in PC3 cell lines revealed a better uptake of CSMS with HP morphology than its spherical counterparts. Cytotoxicity study showed that the anticancer activity of CBZ is improved with a higher free radical production when loaded onto CSMS. These unique materials with tunable morphology can serve as an excellent drug delivery system and will have potential applications for treating various cancers.

High-Throughput Determination of Stern-Volmer Quenching Constants for Common Photocatalysts and Quenchers.

Mechanistic information on reactions proceeding via photoredox catalysis has enabled rational optimizations of existing reactions and revealed new synthetic pathways. One essential step in any photoredox reaction is catalyst quenching via photoinduced electron transfer or energy transfer with either a substrate, additive, or cocatalyst. Identification of the correct quencher using Stern-Volmer studies is a necessary step for mechanistic understanding; however, such studies are often cumbersome, low throughput and require specialized luminescence instruments. This report describes a high-throughput method to rapidly acquire a series of Stern-Volmer constants, employing readily available fluorescence plate readers and 96-well plates. By leveraging multichannel pipettors or liquid dispensing robots in combination with fast plate readers, the sampling frequency for quenching studies can be improved by several orders of magnitude. This new high-throughput method enabled the rapid collection of 220 quenching constants for a library of 20 common photocatalysts with 11 common quenchers. The extensive Stern-Volmer constant table generated greatly facilitates the systematic comparison between quenchers and can provide guidance to the synthetic community interested in designing and understanding catalytic photoredox reactions.

Activated alkyne-enabled turn-on click bioconjugation with cascade signal amplification for ultrafast and high-throughput antibiotic screening

Antimicrobial susceptibility testing plays a pivotal role in the discovery of new antibiotics. However, the development of simple, sensitive, and rapid assessment approaches remains challenging. Herein, we report an activated alkyne-based cascade signal amplification strategy for ultrafast and high-throughput antibiotic screening. First of all, a novel water-soluble aggregation-induced emission (AIE) luminogen is synthesized, which contains an activated alkyne group to enable fluorescence turn-on and metal-free click bioconjugation under physiological conditions. Taking advantage of the in-house established method for bacterial lysis, a number of clickable biological substances (i.e., bacterial solutes and debris) are released from the bacterial bodies, which remarkably increases the quantity of analytes. By means of the activated alkyne-mediated turn-on click bioconjugation, the system fluorescence signal is significantly amplified due to the increased labeling sites as well as the AIE effect. Such a cascade signal amplification strategy efficiently improves the detection sensitivity and thus enables ultrafast antimicrobial susceptibility assessment. By integration with a microplate reader, this approach is further applied to high-throughput antibiotic screening.

Selenium-rich yeast counteracts the inhibitory effect of nanoaluminum on the formation of porcine neutrophil extracellular traps

Aluminum is widely used in daily life due to its excellent properties. However, aluminum exposure to the environment severely threatens animal and human health. Conversely, selenium (Se) contributes to maintaining the balance of the immune system. Neutrophils exert immune actions in several ways, including neutrophil extracellular traps (NETs) that localize and capture exogenous substances. Despite the recent investigations on the toxic effects of aluminum and its molecular mechanisms, the immunotoxicity of aluminum nanoparticles on pigs and the antagonistic effect of selenium on aluminum toxicity are poorly understood. Here, we treated porcine peripheral blood neutrophils with zymosan for 3 h to induce NETs formation. Then, we investigated the effect of nanoaluminum on NETs formation in pigs and its possible molecular mechanisms. Microscopy observations revealed that NETs formation was inhibited by nanoaluminum. Using a multifunctional microplate reader, the production of extracellular DNA and the burst of reactive oxygen species (ROS) in porcine neutrophils were inhibited by nanoaluminum. Western blot analyses showed that nanoaluminum caused changes in amounts of cellular selenoproteins. After Se supplementation, the production of porcine NETs, the burst of ROS, and selenoprotein levels were restored. This study indicated that nanoaluminum inhibited the zymosan-induced burst of ROS and release of NETs from porcine neutrophils, possibly through the selenoprotein signaling pathway. In contrast, Se supplementation reduced the toxic effects of nanoaluminum and restored NETs formation.

Methods for Electroporation and Transformation Confirmation in &lt;em&gt;Limosilactobacillus reuteri&lt;/em&gt; DSM20016

Lactobacillus were an incredibly large, diverse genus of bacteria comprising 261 species, several of which were commensal strains with the potential for use as a chassis for synthetic biological endeavors within the gastrointestinal tract. The wide phenotypic and genotypic variation observed within the genus led to a recent reclassification and the introduction of 23 novel genera. Due to the breadth of variations within the old genera, protocols demonstrated in one member may not work as advertised with other members. A lack of centralized information on how exactly to manipulate specific strains has led to a range of ad hoc approaches, often adapted from other bacterial families. This can complicate matters for researchers starting in the field, who may not know which information does or does not apply to their chosen strain. In this paper, we aim to centralize a set of protocols with demonstrated success, specifically in the Limosilactobacillus reuteri strain designation F275 (other collection numbers: DSM20016, ATCC23272, CIP109823), along with troubleshooting advice and common issues one may encounter. These protocols should enable a researcher with little to no experience working with L. reuteri DSM20016 to transform a plasmid, confirm transformation, and measure system feedback in a plate reader via a reporter protein.