Concentration-dependent Effect Research Articles

Abstract 737: Arrays of 3D ECM-embedded fibroblast clusters for characterization of ECM remodeling by primary cancer associated fibroblasts and for evaluation of drugs attenuating fibrotic ECM remodeling

Abstract Chronic fibrosis can lead to organ failure and is also associated with cancer, where the tumor is interpreted as a chronic wound, and the fibrotic tumor environment drives disease progression. Fibrosis occurs in an inflammatory environment where macrophages are activated, and fibroblasts transdifferentiate into myofibroblasts. Activated macrophages stimulate the myofibroblasts to produce excessive amounts of collagen-rich ECM. Changes in proteolytic activity and high contractile forces that myofibroblasts apply onto their tissue environment, further lead to extensive remodeling of the healthy tissue matrix into a scar matrix. Similar activity is displayed by cancer-associated fibroblasts (CAFs) in tumors. Intervening with the excessive ECM remodeling by activated fibroblasts represents a candidate therapeutic strategy to normalize the architecture of fibrotic and malignant tissues. We developed a screening platform using an assay based on automated image guided injection of clusters of fibroblasts in wells of multi-well plates preloaded with a collagen-rich ECM network. The identical x-y-z position, spacing, and size of the ECM-embedded fibroblast clusters in each well facilitates automated real time confocal microscopy and quantitative image analysis algorithms. We use this setup for automated quantitative analysis of ECM remodeling activity of CAFs obtained from early-stage colorectal cancer patients. We find that CAFs from these early-stage lesions display increased ECM remodeling capacity as compared to patient matched normal fibroblasts. We then use the same setup to screen a series of compounds for their ability to attenuate ECM remodeling triggered by TGFb-activated primary human fibroblasts. We detect known and novel pathways, and we identify small molecule inhibitors with a promising efficacy versus toxicity profile. Lastly, we detect a previously unknown concentration-dependent side effect of ALK5 inhibitors that leads to the identification of a novel profibrotic pathway and indicates that caution is warranted for the clinical application of ALK5 inhibitors. Citation Format: Erik H. J. Danen. Arrays of 3D ECM-embedded fibroblast clusters for characterization of ECM remodeling by primary cancer associated fibroblasts and for evaluation of drugs attenuating fibrotic ECM remodeling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 737.

Selective activation of prodrugs in breast cancer using metabolic glycoengineering and the tetrazine ligation bioorthogonal reaction

Increasing the selectivity of chemotherapies by converting them into prodrugs that can be activated at the tumour site decreases their side effects and allows discrimination between cancerous and non-cancerous cells. Herein, the use of metabolic glycoengineering (MGE) to selectively label MCF-7 breast cancer cells with tetrazine (Tz) activators for subsequent activation of prodrugs containing the trans-cyclooctene (TCO) moiety by a bioorthogonal reaction is demonstrated. Three novel Tz-modified monosaccharides, Ac4ManNTz 7, Ac4GalNTz 8, and Ac4SiaTz 16, were used for expression of the Tz activator within sialic-acid rich breast cancer cells’ surface glycans through MGE. Tz expression on breast cancer cells (MCF-7) was evaluated versus the non-cancerous L929 fibroblasts showing a concentration-dependant effect and excellent selectivity with ≥35-fold Tz expression on the MCF-7 cells versus the non-cancerous L929 fibroblasts. Next, a novel TCO-N-mustard prodrug and a TCO-doxorubicin prodrug were analyzed in vitro on the Tz-bioengineered cells to probe our hypothesis that these could be activated via a bioorthogonal reaction. Selective prodrug activation and restoration of cytotoxicity were demonstrated for the MCF-7 breast cancer cells versus the non-cancerous L929 cells. Restoration of the parent drug’s cytotoxicity was shown to be dependent on the level of Tz expression where the Ac4ManNTz 7 and Ac4GalNTz 8 derivatives (20 µM) lead to the highest Tz expression and full restoration of the parent drug’s cytotoxicity. This work suggests the feasibility of combining MGE and tetrazine ligation for selective prodrug activation in breast cancer.

Essential oils and their blends: mechanism of antibacterial activity and antibiofilm potential on food-grade maize starch packaging films.

Essential oils are highly complex volatile chemical compounds utilized for food preservation. The present study compares the antibacterial, and antibiofilm activities of essential oils (EOs) and their blends. Three EOs-basil, clove, and lemongrass-and their blends were evaluated against five food-borne bacterial pathogens. A concentration-dependent effect with maximum inhibition at minimum inhibitory concentration values was recorded while no synergistic activity was observed on blending of EOs. The mechanism of antibacterial action was identified as ROS burst, leakage of cytoplasmic content, and DNA degradation through fluorescence microscopy, electrical conductivity, and DNA cleavage studies. The role of EOs on biofilm growth was deciphered with lemongrass EO being most effective as it curbed biofilm formation on the surface of corn-starch packaging films. This work highlights the antibacterial action mechanism of EOs and their potential role in curtailing biofilm growth on food-grade packaging material.

Randomized Phase I Trial of the α-Synuclein Antibody Lu AF82422.

Immunotherapy targeting pathological α-synuclein (α-syn) species is a promising strategy for slowing disease progression in neurodegenerative synucleinopathies, including Parkinson's disease (PD). The aim was to evaluate the safety, tolerability, pharmacokinetics, and target engagement of ascending doses of Lu AF82422. In this first-in-human study (NCT03611569), healthy participants (18-55 years, cohort A) and patients with PD (40-80 years, Hoehn and Yahr stage ≤3, cohort B) were enrolled in ascending-dose cohorts and randomly assigned to receive single intravenous infusions of Lu AF82422 (cohorts A1-A6: 75, 225, 750, 2250 4500, and 9000 mg, respectively; cohorts B1 and B2: 2250 and 9000 mg, respectively) or placebo. Participants were monitored during a 12-week observational period. Overall, single intravenous infusions of Lu AF82422 were safe and well tolerated, and no serious adverse events (AE) were observed; the most common AEs were related to the study on lumbar punctures, headache, and common infections. Lu AF82422 concentrations (in plasma and cerebrospinal fluid [CSF]) increased in a dose-proportional manner with no observable differences between cohorts; mean plasma half-life was 700 h. Plasma concentrations of Lu AF82422 had an immediate, concentration-dependent lowering effect on the plasma concentration of free α-syn and on the ratio of free to total α-syn in all cohorts and lowered the free-to-total α-syn ratio in CSF in the high-dose PD cohort. The safety and pharmacokinetic profile of Lu AF82422 were appropriate for further clinical development, and results indicated peripheral target engagement. The central target engagement observed in participants with PD indicates that the doses of Lu AF82422 tested may provide CSF concentrations sufficient to target aggregated forms of α-syn. © 2024 H. Lundbeck A/S. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Antioxidant versus prooxidant properties of the flavonoid, galangin: ROS scavenging activity, flavonoid-DNA interaction, copper-catalyzed Fenton reaction and DNA damage study

Flavonoids are natural antioxidants, found in vegetables, fruits, flowers, coffee, tea, wine, and other foodstuffs. They are well known for their health benefits, and various clinical trials have determined that a sufficient intake of flavonoids is related to lower mortality from cardiovascular diseases, metabolic diseases, and cancer. In addition, flavonoids are of great current interest in regard to sporting activities, in that the intake of these compounds by sportsmen may both shorten their recovery periods and improve their overall health status. In this work, we present results demonstrating the antioxidant, and also prooxidant, properties of the flavonoid, galangin, which is currently under intense investigation as a health supplement. The prooxidant environment has been simulated using Cu-catalyzed-Fenton and Cu-Ascorbate systems. UV–Vis spectroscopy revealed that galangin is coordinated to Cu(II) through oxygen donor atoms from both the benzoyl (4-CO/5-OH groups) and the cinnamoyl (3-OH/4-CO) moieties of the molecule; however, the interaction occurs preferentially via the cinnamoyl unit. The radical scavenging activity of galangin and Cu(II)-galangin complexes were studied using the ABTS assay, which confirmed an inhibitory/scavenging activity of the systems studied, but chelation resulted in only a modest increase in activity. Electronic absorption titrations showed that both free galangin and the Cu(II)-galangin complex interact with DNA through hydrogen-bonding and van der Waals interactions. The values evaluated for the binding constants (K) indicate an intermediate binding strength between the given flavonoid systems and DNA. The results from gel electrophoresis have shown that, in the ROS-producing prooxidant systems, galangin provided a concentration-dependent protective effect against DNA damage via both Cu(II)-chelation and ROS-scavenging mechanisms. The ROS scavengers, l-histidine, DMSO, and SOD, confirmed the formation of singlet oxygen (1O2), hydroxyl radicals (•OH), and superoxide radical anions (O2•−).

Pulmonary surfactant impacts in vitro activity of selected antifungal drugs against Candida krusei and Candida albicans

PurposeThis study investigates how surfactants affect the in-vitro anti-infective efficacy of micafungin, caspofungin, anidulafungin, and amphotericin B in treating pulmonary mycoses.MethodsMIC values for antifungal agents were determined against Candida krusei (now Pichia kudriavzevii) ATCC 6258, Candida albicans ATCC 90028, and 18 clinical isolates using the broth microdilution method in RPMI medium, following EUCAST recommendations. MIC assays included testing with and without Curosurf® surfactant at 1 mg/mL for C. krusei ATCC 6258 and all C. krusei isolates. Subsequent Time-kill studies in Sabouraud broth involved testing both C. albicans ATCC 90028 and C. krusei ATCC 6258 strains at concentrations equal their respective MIC values, with and without surfactant, using all four antifungals. CFU/mL were assessed at multiple time points up to 24 h. TKCs with different surfactant concentrations for C. krusei ATCC 6258 and mini-TKCs at various concentrations relative to the MIC of C. krusei isolates and the reference strain were conducted with micafungin, anidulafungin, and caspofungin.ResultsMIC results showed that 1 µg/mL surfactant reduced killing of micafungin and anidulafungin against C. krusei, while caspofungin was unaffected. Amphotericin B's MIC decreased by half. TKCs demonstrated significant effects of surfactant on micafungin and anidulafungin against C. krusei, with complete abolition of anidulafungin's activity against C. albicans.ConclusionThis in-vitro study highlights the concentration-dependent inhibitory effect of surfactant on antifungal activity against C. krusei and, to some extent, C. albicans, necessitating further clinical validation for invasive lung mycoses treatment.

Restoration of Antibacterial Activity of Inactive Antibiotics via Combined Treatment with AgNPs.

Antimicrobial resistance poses a huge threat to human health around the world and calls for novel treatments. Combined formulations of NPs and antibiotics have emerged as a viable nanoplatform for combating bacterial resistance. The present research work was performed to investigate the effect of combined formulations of AgNPs with streptomycin, cefaclor, ciprofloxacin, and trimethoprim against multidrug-resistant (MDR) isolates of Staphylococcus aureus and Klebsiella pneumoniae. AgNPs have been synthesized by using the Nigella sativa seed extract, and their characteristics were analyzed. AgNPs depicted concentration-dependent antibacterial effects, as the highest concentration of AgNPs showed the strongest antibacterial activity. Interestingly, AgNPs in conjugation with antibiotics showed an enhanced antibacterial potential against both S. aureus and K. pneumoniae, which suggested synergism between the AgNPs and antibiotics. Against S. aureus, streptomycin and trimethoprim in conjugation with AgNPs presented a synergistic effect, while cefaclor and ciprofloxacin in combination with AgNPs showed an additive effect. However, all of the tested antibiotics depicted a synergistic effect against K. pneumoniae. The lowest value of MIC (0.78 μg/mL) was shown by AgNPs-Stp against S. aureus, whereas AgNPs-Tmp showed the lowest value of MIC (1.56 μg/mL) against K. pneumoniae. The most important point of the present study is that both organisms (S. aureus and K. pneumoniae) showed resistance to antibiotics but turned out to be highly susceptible when the same antibiotic was used in combination with AgNPs. These findings highlight the potential of nanoconjugates (the AgNPs-antibiotic complex) to mitigate the present-day crisis of antibiotic resistance and to combat antimicrobial infections efficiently.

Two-way pharmacodynamic modeling of drug combinations and its application to pairs of repurposed Ebola and SARS-CoV-2 agents.

Existing pharmacodynamic (PD) mathematical models for drug combinations discriminate antagonistic, additive, multiplicative, and synergistic effects, but fail to consider how concentration-dependent drug interaction effects may vary across an entire dose-response matrix. We developed a two-way pharmacodynamic (TWPD) model to capture the PD of two-drug combinations. TWPD captures interactions between upstream and downstream drugs that act on different stages of viral replication, by quantifying upstream drug efficacy and concentration-dependent effects on downstream drug pharmacodynamic parameters. We applied TWPD to previously published in vitro drug matrixes for repurposed potential anti-Ebola and anti-SARS-CoV-2 drug pairs. Depending on the drug pairing, the model recapitulated combined efficacies as or more accurately than existing models and can be used to infer efficacy at untested drug concentrations. TWPD fits the data slightly better in one direction for all drug pairs, meaning that we can tentatively infer the upstream drug. Based on its high accuracy, TWPD could be used in concert with PK models to estimate the therapeutic effects of drug pairs in vivo.

Synthesis of chitosan-graphene oxide thermosensitive in situ hydrogel for nasal delivery of rasagiline mesylate: In-vitro-ex vivo characterization

Intranasal administration of a drug offers a way to bypass the blood-brain barrier, allowing for an increased drug concentration in the brain and improved bioavailability. In this context, the preference for polymeric thermoresponsive intranasal hydrogels has been widely documented. Here, there is a need to enhance the physical properties of the hydrogel and improve control over the release of the drug. In this work, we propose the incorporation of graphene oxide (GO) into a thermosensitive in situ hydrogel (RM@CS/B-GP-GO) based on chitosan (CS) and beta-glycerophosphate (B-GP) for intranasal delivery of rasagiline mesylate (RM). The prepared in situ hydrogel formulations were characterized using gelation temperature, gelation time, swelling, porosity, gel strength, mucoadhesive strength, pH, morphological features, spectral analysis, drug release, permeation study, and so on. In this work, the incorporation of GO showed a significant concentration-dependent effect on the properties of the thermosensitive CS hydrogel. In brief, the addition of GO in RM@CS/B-GP decreased the gelation time, porosity, and swelling of the hydrogel. Additionally, CS-hydrogel strength increased with higher concentrations of GO. The RM@CS/B-GP-GO hydrogel (1 mg/mL of GO) showed the customized release of RM almost 68.41 ± 2.01 % in 8 h than the RM@CS/B-GP hydrogel (log p < 0.05). Based on these findings, the physical and mechanical properties of the RM@CS/B-GP-GO thermosensitive hydrogel were improved by the addition of optimized concentration GO. Moreover, RM@CS/B-GP-GO hydrogel shows good biocompatibility with nasal mucosa. Overall, the design of RM@CS/B-GP-GO can open new options for the delivery of RM through the nasal route.

Unphysical grain size dependence of lattice thermal conductivity in Mg3(Sb, Bi)2: An atomistic view of concentration dependent segregation effects

Grain boundary (GB) engineering is one of the most common strategies to reduce the lattice thermal conductivity and improve thermoelectric materials. However, in the case of the promising thermoelectric material Mg3(Sb1−xBix)2, an abnormal dependence of lattice thermal conductivity on grain size was observed at the concentration of x = 0.25, where smaller grain polycrystalline materials exhibited higher lattice thermal conductivity compared to larger grain materials. The proposed theory about the overestimation of lattice thermal conductivity in inhomogeneous materials with GBs cannot clarify the concentration dependence of this anomaly. Here we elucidate the interplay between segregation, concentration, and lattice thermal conductivity in Mg3(Sb1−xBix)2 alloys through atomistic simulations with a highly accurate machine learning interatomic potential. We find the largest segregation of Bi atoms to GBs in Mg3(Sb1−xBix)2 at the concentration of x = 0.25 for both twist and tilt GB structures due to the combination effects of site spectrality and solute interactions. Our molecular dynamic simulations demonstrate that the pronounced segregation of heavier Bi atoms, particularly at x = 0.25, leads to a substantial increase in the lattice thermal resistance at GBs, thus contributing to the degree of inhomogeneity. The concentration dependent segregation reveals the atomic origin of the observed unphysical inverse relationship between grain size and lattice thermal conductivity at the specific concentration of x = 0.25. These results highlight the need to design the alloy concentration to tune the atomic segregation and tailor the thermal properties of thermoelectric materials with GBs.

The concentration-dependent effect of NaOH on graphene oxide: Revisited as a reducing agent

Prudent knowledge of the factors in the chemical synthesis of reduced graphene oxide (rGO) can provide a considerable impetus for the precise repeatability needed for the technological adoption of graphene nanocomposites. Sodium Hydroxide (NaOH) is a common ingredient in the synthesis of rGO. The paper presents a systematic study of the effect of NaOH concentration on graphene oxide (GO). The threshold value, where NaOH starts acting as a reducing agent, is proposed in the paper. The finding was corroborated based on absorbance maxima obtained from the UV–Visible spectrum (π - π* transitions) and the peak intensity ratio of Raman spectra. The results indicate that NaOH has a remarkable role in tuning the functionality of graphene oxide. Furthermore, it is demonstrated that pH is not a critical factor in GO reduction. All these findings are vital to the NaOH-based pH tuning and industrial scaling of graphene-based nanocomposite synthesis.

Phosphatase-degradable nanoparticles providing sustained drug release

AimThe study aimed to develop enzyme-degradable nanoparticles comprising polyphosphates and metal cations providing sustained release of the antibacterial drug ethacridine (ETH). MethodsCalcium polyphosphate (Ca-PP), zinc polyphosphate (Zn-PP) and iron polyphosphate nanoparticles (Fe-PP NPs) were prepared by co-precipitation of sodium polyphosphate with cations and ETH. Developed nanocarriers were characterized regarding particle size, PDI, zeta potential, encapsulation efficiency and drug loading. Toxicological profile of nanocarriers was assessed via hemolysis assay and cell viability on human blood erythrocytes and HEK-293 cells, respectively. The enzymatic degradation of NPs was evaluated in presence of alkaline phosphatase (ALP) monitoring the release of monophosphate, shift in zeta potential and particle size as well as drug release. The antibacterial efficacy against Escherichia coli was determined via microdilution assay. ResultsNPs were obtained in a size range between 300 – 480 nm displaying negative zeta potential values. Encapsulation efficiency was in the range of 83.73 %– 95.99 %. Hemolysis assay underlined sufficient compatibility of NPs with blood cells, whereas drug and NPs showed a concentration dependent effect on HEK-293 cells viability. Ca- and Zn-PP NPs exhibited remarkable changes in zeta potential, particle size, monophosphate and drug release upon incubation with ALP, compared to Fe-PP NPs showing only minor differences. The released ETH from Ca- and Zn-PP nanocarriers retained the antibacterial activity against E. coli, whereas no antibacterial effect was observed with Fe-PP NPs. ConclusionPolyphosphate nanoparticles cross-linked with divalent cations and ETH hold promise for sustained drug delivery triggered by ALP for parental administration.

Advancing nerve regeneration: Peripheral nerve injury (PNI) chip empowering high-speed biomaterial and drug screening

Peripheral nerve injuries (PNIs) represent a significant challenge in regenerative medicine, often leading to long-term functional impairments. In this study, we introduce the peripheral nerve injury-on-a-chip (PNI chip), a cutting-edge platform designed for high-speed screening of biomaterials and drugs to enhance peripheral nerve regeneration. The PNI chip combines aligned nanofibers as topographical cues with microfluidic technology to create a controlled and versatile environment for investigating key factors influencing axonal growth and regeneration. Our study reveals that density of aligned nanofibers plays a pivotal role in axonal regeneration regarding regeneration velocity and the recovery of damaged axonal areas. Additionally, we investigate the dynamic interactions between regenerating axons and aligned nanofibers, shedding light on the adaptability of axonal growth cones to topographical cues. Moreover, the PNI chip serves as a potent tool for drug screening, as demonstrated by our evaluation of paclitaxel and M1. Paclitaxel exhibits concentration-dependent effects, while M1, a mitochondria fusion promoter, substantially enhances axonal growth velocity, emphasizing the potential of mitochondria dynamics as a target for improving nerve regeneration. The PNI chip represents a breakthrough in peripheral nerve regeneration research, offering the means to systematically explore nanofiber parameters and drug interventions in a controlled and high-throughput manner.

Dinotefuran exposure alters biochemical, metabolomic, gut microbiome, and growth responses in decapoda pacific white shrimp Penaeus vannamei

Dinotefuran, a neonicotinoid insecticide, may impact nontarget organisms such as Decapoda P. vannamei shrimp with nervous systems similar to insects. Exposing shrimp to low dinotefuran concentrations (6, 60, and 600 μg/L) for 21 days affected growth, hepatosomatic index, and survival. Biomarkers erythromycin-N-demethylase, alanine aminotransferase, and catalase increased in all exposed groups, while glutathione S-transferase is the opposite; aminopyrin-N-demethylase, malondialdehyde, and aspartate aminotransferase increased at 60 and 600 μg/L. Concentration-dependent effects on gut microbiota altered the abundance of bacterial groups, increased potentially pathogenic and oxidative stress-resistant phenotypes, and decreased biofilm formation. Gram-positive/negative microbiota changed significantly. Metabolite differences between the exposed and control groups were identified using mass spectrometry and KEGG pathway enrichment. N-acetylcystathionine showed potential as a reliable dinotefuran metabolic marker. Weighted correlation network analysis (WGCNA) results indicated high connectivity of cruecdysone in the metabolite network and significant enrichment at 600 μg/L dinotefuran. The WGCNA results revealed a highly significant negative correlation between two key metabolites, caldine and indican, and the gut microbiota within co-expression modules. Overall, the risk of dinotefuran exposure to non-target organisms in aquatic environments still requires further attention.

Comprehensive in vitro and in ovo assessment of cytotoxicity: Unraveling the impact of sodium fluoride, xylitol, and their synergistic associations in dental products.

Over the past several decades, dental health products containing fluoride have been widely employed to mitigate tooth decay and promote oral hygiene. However, concerns regarding the potential toxicological repercussions of fluoride exposure have incited continuous scientific inquiry. The current study investigated the cytotoxicity of sodium fluoride (NaF) and xylitol (Xyl), both individually and in combination, utilizing human keratinocyte (HaCaT) and osteosarcoma (SAOS-2) cell lines. In HaCaT cells, NaF decreased proliferation in a concentration-dependent manner and induced apoptosis-related morphological changes at low concentrations, whereas Xyl exhibited dose-dependent cytotoxic effects. The combination of NaF and Xyl reduced cell viability, particularly at higher concentrations, accompanied by apoptosis-like morphological alterations. Sub-cytotoxic NaF concentrations (0.2%) significantly affected caspase activity and the expression of pro-apoptotic genes. Conversely, Xyl demonstrated no discernible effect on these biological parameters. In SAOS-2 cells, NaF increased proliferation at high concentrations, contrasting with Xyl's concentration-dependent cytotoxic effects. The combination of NaF and Xyl had a minimal impact on cell viability. Sub-cytotoxic NaF concentrations did not influence caspase activity or gene expression, while Xyl induced dose-dependent morphological alterations, increased caspase activity, and upregulated pro-apoptotic gene expression. In ovo experiments on the chorioallantoic membrane (CAM) revealed that only NaF induced irritant effects, suggesting potential vascular adverse outcomes. This study advocates for the combined use of NaF and Xyl, highlighting their cytotoxicity benefits in healthy cells while maintaining safety considerations for tumor cells.

Oxidovanadium(V) complexes with chiral tetradentate Schiff bases: Synthesis, spectroscopic characterization, catalytic and biological activity

New mononuclear oxidovanadium(V) complexes, [(−)VOL1–10] and [(+)VOL1–4], with chiral tetradentate Schiff bases have been obtained by monocondensation of salicylaldehyde derivatives and optically active amino alcohols, i.e. 1R,2R-(−)-2-amino-1-phenyl-1,3-propanediol or 1S,2S-(+)-2-amino-1-phenyl-1,3-propanediol. All complexes have been characterized by elemental analysis, circular dichroism, UV–vis, IR, 1D (1H, 51V) and 2D (COSY, NOESY) NMR spectroscopy. The catalytic activity studies have also been performed for all complexes in the epoxidation of styrene, cyclohexene and two monoterpenes, i.e. S(−)-limonene and (−)-α-pinene, using aqueous 30 % H2O2 or tert-butyl hydroperoxide (TBHP) as the terminal oxidant. In addition, biological properties of these chiral oxidovanadium(V) compounds, as well as cis-dioxidomolybdenum(VI) complexes with the same chiral Schiff bases, were studied in relation to their cytoprotective activity against the oxidative damage generated exogenously by 30 % hydrogen peroxide in the HT-22 hippocampal neuronal cells. The latter compounds have revealed distinct cytoprotective properties causing the highest increase in the viability of HT-22 cells. Concentration dependent effect in the range of 10-100 μM concentration of the investigated compounds has also been observed.

Evaluation of the cardiac safety of parsaclisib, a selective PI3Kδ inhibitor, in patients with previously treated B-cell malignancies: Results from the CITADEL-101 study.

Parsaclisib, a potent and selective phosphatidylinositol 3 kinase δ inhibitor, has been investigated for the treatment of B-cell malignancies and studied in patients with autoimmune diseases and myelofibrosis. The CITADEL-101 study (NCT02018861) assessed safety, tolerability, and preliminary efficacy of parsaclisib in patients with relapsed or refractory non-Hodgkin lymphoma. This study evaluated the cardiac safety of parsaclisib as monotherapy based on data from 72 patients enrolled in the CITADEL-101 study. Time-matched pharmacokinetic and ECG measurements were collected at specified times for 69 patients receiving monotherapy in doses of 5, 10, 15, 20, 30, and 45 mg once daily. Based on the categorical outlier analysis, no dose-dependent effect was observed on the incidence of outliers in QT interval corrected for heart rate (HR) by Fridericia's method (QTcF), HR, or cardiac conduction. Based on central tendency analysis, the least square means (LSMs) (90% confidence interval [CI]) of ΔQTcF from the central tendency analysis ranged from -6.83 (-18.8 to 5.19) to 4.75 ms (0.410-9.09) across dose groups (below 20 ms, the threshold of large QT effects) and was not considered dose dependent. Moreover, the LSMs of ΔHR, ΔPR interval, and ΔQRS interval were minor. From the concentration-ΔQTcF analyses, the predicted ΔQTcF (90% CI) for all dose levels was between 0.365 (-1.75 to 2.48) and 7.87 ms (0.921-14.8), with the highest upper limit of CIs well below 20 ms, and therefore, a large QT/QTc effect was ruled out up to the highest dose level (45 mg) investigated. Overall, parsaclisib at the dose ranges studied did not reveal concentration-dependent effects on change in QTcF and did not have a significant effect on HR or cardiac conduction.

Analysis of Poly(ethylene terephthalate) degradation kinetics of evolved IsPETase variants using a surface crowding model

Poly(ethylene terephthalate) (PET) is a major plastic polymer utilized in the single-use and textile industries. The discovery of PET-degrading enzymes (PETases) has led to an increased interest in the biological recycling of PET in addition to mechanical recycling. IsPETase from Ideonella sakaiensis is a candidate catalyst, but little is understood about its structure-function relationships with regards to PET degradation. To understand the effects of mutations on IsPETase productivity, we develop a directed evolution assay to identify mutations beneficial to PET film degradation at 30ºC. IsPETase also displays enzyme concentration-dependent inhibition effects, and surface crowding has been proposed as a causal phenomenon. Based on total internal reflectance fluorescence microscopy and adsorption experiments, IsPETase is likely experiencing crowded conditions on PET films. Molecular dynamics (MD) simulations of IsPETase variants reveal a decrease in active site flexibility in free enzymes and reduced probability of productive active site formation in substrate-bound enzymes under crowding. Hence, we develop a surface crowding model to analyze the biochemical effects of three hit mutations (T116P, S238N, S290P) that enhanced ambient temperature activity and/or thermostability. We find that T116P decreases susceptibility to crowding, resulting in higher PET degradation product accumulation despite no change in intrinsic catalytic rate. In conclusion, we show that a macromolecular crowding-based biochemical model can be used to analyze the effects of mutations on properties of PETases and that crowding behavior is a major property to be targeted for enzyme engineering for improved PET degradation.

Multifaceted Applications of DNA-Capped Silver Nanoparticles in Photonics, Photocatalysis, Antibacterial Activity, Cytotoxicity, and Bioimaging.

Deoxyribonucleic acid (DNA) capped silver nanoparticles are exceptional nanomaterials, featuring precise size and shape control enabled by DNA as a capping agent. DNA stabilizes these nanoparticles' role leading to uniform structures for diverse applications. These nanoparticles are excellent in photonics and medical applications, enhancing fluorescence and medical imaging. In this study, we explore the multifaceted applications of DNA-capped silver nanoparticles, delving into their optical, photocatalytic, antibacterial, cytotoxic, and bioimaging properties. Employing UV-visible absorption spectroscopy and scanning electron microscopy, we provide an analysis of confirmation of silver nanoparticles. The investigation demonstrates substantial photocatalytic efficacy, photodegradation of methylene blue is higher than rhodamine 6G. The presence of silver nanoparticles enhances the fluorescence of rhodamine 6G doped sol-gel glasses. Furthermore, our findings illustrate significant antibacterial effects, encompassing both Gram-positive and Gram-negative bacteria, with DNA-capped silver nanoparticles exhibiting antibacterial activity. Cytotoxicity assessments on HeLa cells reveal concentration-dependent effects, with an LC50 value of 47 µL. Additionally, thein vitro experiments with HeLa cells suggest the promising utility of DNA-capped silver nanoparticles for bioimaging applications. This comprehensive analysis highlights the multifunctionality and potential of DNA-capped silver nanoparticles, offering promising avenues for further exploration and innovation within various scientific domains, particularly in the realm of nanomaterial research.

Dysregulation of the mRNA Expression of Human Renal Drug Transporters by Proinflammatory Cytokines in Primary Human Proximal Tubular Epithelial Cells.

Proinflammatory cytokines, which are elevated during inflammation or infections, can affect drug pharmacokinetics (PK) due to the altered expression or activity of drug transporters and/or metabolizing enzymes. To date, such studies have focused on the effect of cytokines on the activity and/or mRNA expression of hepatic transporters and drug-metabolizing enzymes. However, many antibiotics and antivirals used to treat infections are cleared by renal transporters, including the basal organic cation transporter 2 (OCT2), organic anion transporters 1 and 3 (OAT1 and 3), the apical multidrug and toxin extrusion proteins 1 and 2-K (MATE1/2-K), and multidrug resistance-associated protein 2 and 4 (MRP2/4). Here, we determined the concentration-dependent effect of interleukin-6 (IL-6), IL-1β, tumor necrosis factor (TNF)-α, and interferon-γ (IFN-γ) on the mRNA expression of human renal transporters in freshly isolated primary human renal proximal tubular epithelial cells (PTECs, n = 3-5). PTECs were exposed to either a cocktail of cytokines, each at 0.01, 0.1, 1, or 10 ng/mL or individually at the same concentrations. Exposure to the cytokine cocktail for 48 h was found to significantly downregulate the mRNA expression, in a concentration-dependent manner, of OCT2, the organic anion transporting polypeptides 4C1 (OATP4C1), OAT4, MATE2-K, P-glycoprotein (P-gp), and MRP2 and upregulate the mRNA expression of the organic cation/carnitine transporter 1 (OCTN1) and MRP3. OAT1 and OAT3 also appeared to be significantly downregulated but only at 0.1 and 10 ng/mL, respectively, without a clear concentration-dependent trend. Among the cytokines, IL-1β appeared to be the most potent at down- and upregulating the mRNA expression of the transporters. Taken together, our results demonstrate for the first time that proinflammatory cytokines transcriptionally dysregulate renal drug transporters in PTECs. Such dysregulation could potentially translate into changes in transporter protein abundance or activity and alter renal transporter-mediated drug PK during inflammation or infections.