Objective: To evaluate the efficacy and safety of nanocrystallized fenofibrate (Tricor) in severe COVID-19 patients as an adjunct to standard care. Design: Randomized, double-blind, placebo-controlled trial. Setting: Hospitalized patients with severe COVID-19. Participants: 33 severe hospitalized COVID-19 patients randomized to receive either fenofibrate or placebo alongside standard care. Interventions: Participants received 145 mg/day of nanocrystallized fenofibrate or placebo for 10 days, in addition to standard COVID-19 treatment protocols. Main Outcome Measures: Primary outcomes included the number of oxygen-free days, defined as the days patients were not on supplemental oxygen from the start of treatment until discharge, the length of hospital stay measured from admission to discharge, and the viral clearance rate assessed through periodic nasopharyngeal swabs and measured as the decrease in viral load over time. Secondary outcomes included changes in immunoinflammatory markers such as neutrophil and lymphocyte counts, C-reactive protein (CRP), and interleukin-6 (IL-6) levels, the need for advanced respiratory support including high-flow oxygen therapy, mechanical ventilation, or extracorporeal membrane oxygenation (ECMO), and all-cause mortality within 90 days of admission.Results: Fenofibrate significantly increased the median number of oxygen-free days by 16% compared to placebo (10.5 vs. 9.0 days, p=0.042). Additionally, fenofibrate significantly reduced the median length of hospital stay by 28% (6.5 vs. 9.0 days, p=0.045). The viral clearance rate was also notably improved with fenofibrate, showing a 2.4-fold increase, with a median viral clearance rate of 1.33 log10 FC/day compared to 0.56 log10 FC/day in the placebo group (p=0.03). Immunoinflammatory markers indicated better disease progression in the fenofibrate group, with a significant reduction in plasma neutrophil counts (median increase of 1.13 vs. 2.74 x10^3 cells/mL, p=0.049) and a significant increase in plasma lymphocyte counts (median increase of 0.64 vs. 0.16 x10^3 cells/mL, p=0.008). No mortality was observed in the fenofibrate group, presenting a significant survival advantage over the placebo group, which had a 33.3% mortality rate (p=0.013). Fenofibrate also reduced the need for advanced respiratory support, significantly lowering the need for mechanical ventilation or ECMO (0% vs. 33.3%, p=0.013) and showing a trend towards reduced high-flow oxygen therapy requirements (5.6% vs. 33.3%, p=0.07). The safety profile of fenofibrate was comparable to placebo, with no significant adverse events reported. Conclusions: Fenofibrate shows promise as an adjunctive treatment for severe COVID-19, improving clinical outcomes such as increasing oxygen-free days, reducing hospital stay, and enhancing viral clearance, while also exhibiting a favorable safety profile. Larger-scale trials are warranted to confirm these findings. Trial Registration: ClinicalTrials.gov NCT04661930. Funding: Funding was provided by the generous gifts of the Nikoh Foundation and the Sam and Rina Frankel Foundation (YN). The interventional study was supported by Abbott (project FENOC0003). Declaration of Interest: We declare no competing interest. Ethical Approval: The study was reviewed and approved by the Barzilai Medical Center Research Ethics Committee (0105-20-BRZ).

The escalating global demand for meat products has intensified ecological concerns, underscoring the need for sustainable meat alternatives. Although current methods effectively imitate ground meat, mimicking whole cuts, which constitute 54% of the global market, remains challenging due to the lack of scalable technology. Injection molding is a massively scalable manufacturing technology developed for the polymer industry. Here, we introduce two injectable metamaterials: a thermally irreversible fat composite we named proteoleogel, and a multi-scaled meat analog produced by low-temperature extrusion. Viscoelastic screening of plant proteins identifies mung bean for its ability to stabilize complex oleogel structures, mimicking the mechanics of adipose tissue. Mechanical analysis reveals that low-temperature extrusion produces microscale isotropic fibers and mesoscale anisotropic structures mimicking muscle and fascia. These metamaterials can be injection-molded into various whole cuts, from chops to T-bones. Blinded taste tests indicate a 43% preference for our plant-based steak analog. Moreover, technical economic analysis shows injection molding is more cost-effective than 3D printing, costing $9/kg compared to $38/kg. This research represents a step in sustainable food production, offering cost-effective and scalable solutions for the entire meat market.

Background: Viral infection is associated with a significant rewire of the host metabolic pathways, presenting attractive metabolic targets for intervention. Methods: We chart the metabolic response of lung epithelial cells to SARS-CoV-2 infection in primary cultures and COVID-19 patient samples and perform in vitro metabolism-focused drug screen on primary lung epithelial cells infected with different strains of the virus. We perform observational analysis of Israeli patients hospitalized due to COVID-19 and comparative epidemiological analysis from cohorts in Italy and the Veteran’s Health Administration in the United States. In addition, we perform a prospective non-randomized interventional open-label study in which 15 patients hospitalized with severe COVID-19 were given 145 mg/day of nanocrystallized fenofibrate added to the standard of care. Results: SARS-CoV-2 infection produced transcriptional changes associated with increased glycolysis and lipid accumulation. Metabolism-focused drug screen showed that fenofibrate reversed lipid accumulation and blocked SARS-CoV-2 replication through a PPARα-dependent mechanism in both alpha and delta variants. Analysis of 3233 Israeli patients hospitalized due to COVID-19 supported in vitro findings. Patients taking fibrates showed significantly lower markers of immunoinflammation and faster recovery. Additional corroboration was received by comparative epidemiological analysis from cohorts in Europe and the United States. A subsequent prospective non-randomized interventional open-label study was carried out on 15 patients hospitalized with severe COVID-19. The patients were treated with 145 mg/day of nanocrystallized fenofibrate in addition to standard-of-care. Patients receiving fenofibrate demonstrated a rapid reduction in inflammation and a significantly faster recovery compared to patients admitted during the same period. Conclusions: Taken together, our data suggest that pharmacological modulation of PPARα should be strongly considered as a potential therapeutic approach for SARS-CoV-2 infection and emphasizes the need to complete the study of fenofibrate in large randomized controlled clinical trials. Funding: Funding was provided by European Research Council Consolidator Grants OCLD (project no. 681870) and generous gifts from the Nikoh Foundation and the Sam and Rina Frankel Foundation (YN). The interventional study was supported by Abbott (project FENOC0003). Clinical trial number: NCT04661930.

The study of cardiac physiology is hindered by physiological differences between humans and small-animal models. Here we report the generation of multi-chambered self-paced vascularized human cardiac organoids formed under anisotropic stress and their applicability to the study of cardiac arrhythmia. Sensors embedded in the cardiac organoids enabled the simultaneous measurement of oxygen uptake, extracellular field potentials and cardiac contraction at resolutions higher than 10 Hz. This microphysiological system revealed 1 Hz cardiac respiratory cycles that are coupled to the electrical rather than the mechanical activity of cardiomyocytes. This electro-mitochondrial coupling was driven by mitochondrial calcium oscillations driving respiration cycles. Pharmaceutical or genetic inhibition of this coupling results in arrhythmogenic behaviour. We show that the chemotherapeutic mitoxantrone induces arrhythmia through disruption of this pathway, a process that can be partially reversed by the co-administration of metformin. Our microphysiological cardiac systems may further facilitate the study of the mitochondrial dynamics of cardiac rhythms and advance our understanding of human cardiac physiology.

Cellular agriculture could meet growing demand for animal products, but yields are typically low and regulatory bodies restrict genetic modification for cultured meat production. Here we demonstrate the spontaneous immortalization and genetic stability of fibroblasts derived from several chicken breeds. Cell lines were adapted to grow as single-cell suspensions using serum-free culture medium, reaching densities of 108 × 106 cells per ml in continuous culture, corresponding to yields of 36% w/v. We show that lecithin activates peroxisome proliferator-activated receptor gamma (PPARγ), inducing adipogenesis in immortalized fibroblasts. Blending cultured adipocyte-like cells with extruded soy protein, formed chicken strips in which texture was supported by animal and plant proteins while aroma and flavour were driven by cultured animal fat. Visual and sensory analysis graded the product 4.5/5.0, with 85% of participants extremely likely to replace their food choice with this cultured meat product. Immortalization without genetic modification and high-yield manufacturing are critical for the market realization of cultured meat. Immortalized chicken fibroblasts grown in serum-free media yield up to 36% w/v. Direct transdifferentiation generates adipocytes that, when blended with extruded soy protein, produce cultured chicken comparable with chicken breast.

The combination of gene therapy and immunotherapy concepts, along recent advances in DNA nanotechnology, have the potential to provide important tools for cancer therapies. We present the development of stimuli-responsive microcapsules, loaded with a viral immunogenetic agent, harnessing the immune response against the Coronavirus Disease 2019, COVID-19, to selectively attack liver cancer cells (hepatoma) or recognize breast cancer or hepatoma, by expression of green fluorescence protein, GFP. The pH-responsive microcapsules, modified with DNA-tetrahedra nanostructures, increased hepatoma permeation by 50 %. Incorporation of a GFP-encoding lentivirus vector inside the tumor-targeting pH-stimulated miRNA-triggered and Alpha-fetoprotein-dictated microcapsules enables the demonstration of neoplasm selectivity, with approximately 5,000-, 8,000- and 50,000-fold more expression in the cancerous cells, respectively. The incorporation of the SARS-CoV-2 spike protein in the gene vector promotes specific recognition of the immune-evading hepatoma by the COVID-19-analogous immune response, which leads to cytotoxic and inflammatory activity, mediated by serum components taken from vaccinated or recovered COVID-19 patients, resulting in effective elimination of the hepatoma (>85 % yield).

Aminoglycosides are an important class of antibiotics that play a critical role in the treatment of life-threatening infections, but their use is limited by their toxicity. In fact, gentamicin causes severe nephrotoxicity in 17% of hospitalized patients. The kidney proximal tubule is particularly vulnerable to drug-induced nephrotoxicity due to its role in drug transport. In this work, we developed a perfused vascularized model of human kidney tubuloids integrated with tissue-embedded microsensors that track the metabolic dynamics of aminoglycoside-induced renal toxicity in real time. Our model shows that gentamicin disrupts proximal tubule polarity at concentrations 20-fold below its TC50, leading to a 3.2-fold increase in glucose uptake, and reverse TCA cycle flux culminating in a 40-fold increase in lipid accumulation. Blocking glucose reabsorption using the SGLT2 inhibitor empagliflozin significantly reduced gentamicin toxicity by 10-fold. These results demonstrate the utility of sensor-integrated kidney-on-chip platforms to rapidly identify new metabolic mechanisms that may underly adverse drug reactions. The results should improve our ability to modulate the toxicity of novel aminoglycosides.

Severe acute respiratory syndrome (SARS)-CoV-2 infection leads to severe disease associated with cytokine storm, vascular dysfunction, coagulation, and progressive lung damage. It affects several vital organs, seemingly through a pathological effect on endothelial cells. The SARS-CoV-2 genome encodes 29 proteins, whose contribution to the disease manifestations, and especially endothelial complications, is unknown. We cloned and expressed 26 of these proteins in human cells and characterized the endothelial response to overexpression of each, individually. Whereas most proteins induced significant changes in endothelial permeability, nsp2, nsp5_c145a (catalytic dead mutant of nsp5), and nsp7 also reduced CD31, and increased von Willebrand factor expression and IL-6, suggesting endothelial dysfunction. Using propagation-based analysis of a protein–protein interaction (PPI) network, we predicted the endothelial proteins affected by the viral proteins that potentially mediate these effects. We further applied our PPI model to identify the role of each SARS-CoV-2 protein in other tissues affected by coronavirus disease (COVID-19). While validating the PPI network model, we found that the tight junction (TJ) proteins cadherin-5, ZO-1, and β-catenin are affected by nsp2, nsp5_c145a, and nsp7 consistent with the model prediction. Overall, this work identifies the SARS-CoV-2 proteins that might be most detrimental in terms of endothelial dysfunction, thereby shedding light on vascular aspects of COVID-19.

Viruses are efficient metabolic engineers that actively rewire host metabolic pathways to support their lifecycle, presenting attractive metabolic targets for intervention. Here we chart the metabolic response of lung epithelial cells to SARS-CoV-2 infection in primary cultures and COVID-19 patient samples. Bulk and single-cell analyses show that viral replication induces endoplasmic stress and lipid accumulation. Protein expression screen suggests a role for viral proteins in mediating this metabolic response even in the absence of replication. Metabolism-focused drug screen showed that fenofibrate reversed lipid accumulation and blocked SARS-CoV-2 replication. Analysis of 3,233 Israeli patients hospitalized due to COVID-19 supported in vitro findings. Patients taking fibrates showed significantly lower markers of immunoinflammation and faster recovery. Additional corroboration was received by comparative epidemiological analysis from cohorts in Europe and the United States. A subsequent prospective interventional open-label study was carried out in 15 patients hospitalized with severe COVID-19. The patients were treated with 145 mg/day of nanocrystallized fenofibrate (TriCor®) in addition to standard-of-care. Patients receiving fenofibrate demonstrated a rapid reduction in inflammation and a significantly faster recovery compared to control patients admitted during the same period and treated with the standard-of-care. Taken together, our data show that elevated lipid metabolism underlies critical aspects of COVID-19 pathogenesis, suggesting that pharmacological modulation of lipid metabolism should be strongly considered for the treatment of coronavirus infection.

The kidney plays a critical role in fluid homeostasis, glucose control, and drug excretion. Loss of kidney function due to drug-induced nephrotoxicity affects over 20% of the adult population. The kidney proximal tubule is a complex vascularized structure that is particularly vulnerable to drug-induced nephrotoxicity. Here, we introduce a model of vascularized human kidney spheroids with integrated tissue-embedded microsensors for oxygen, glucose, lactate, and glutamine, providing real-time assessment of cellular metabolism. Our model shows that both the immunosuppressive drug cyclosporine and the anticancer drug cisplatin disrupt proximal tubule polarity at subtoxic concentrations, leading to glucose accumulation and lipotoxicity. Impeding glucose reabsorption using glucose transport inhibitors blocked cyclosporine and cisplatin toxicity by 1000- to 3-fold, respectively. Retrospective study of 247 patients who were diagnosed with kidney damage receiving cyclosporine or cisplatin in combination with the sodium-glucose cotransporter-2 (SGLT2) inhibitor empagliflozin showed significant (P < 0.001) improvement of kidney function, as well as reduction in creatinine and uric acid, markers of kidney damage. These results demonstrate the potential of sensor-integrated kidney-on-chip platforms to elucidate mechanisms of action and rapidly reformulate effective therapeutic solutions, increasing drug safety and reducing the cost of clinical and commercial failures.

Inspired by nature, where dynamic networks control the levels of gene expression and the activities of transcribed/translated proteins, we introduce nucleic acid-based constitutional dynamic networks (CDNs) as functional modules mimicking native circuits by demonstrating CDNs-guided programmed synthesis of genes, controlled transcription of RNAs, and dictated transcription/translation synthesis of proteins. An auxiliary CDN consisting of four dynamically equilibrated constituents AA', AB', BA', and BB' is orthogonally triggered by two different inputs yielding two different compositionally reconfigured CDNs. Subjecting the parent auxiliary CDN to two hairpins, HA and HB, and two templates TA and TB and a nicking/replication machinery leads to the cleavage of the hairpins and to the activation of the nicking/replication machineries that synthesize two "genes", e.g., the histidine-dependent DNAzyme g1 and the Zn2+-ion-dependent DNAzyme g2. The triggered orthogonal reconfiguration of the parent CDN to the respective CDNs leads to the programmed preferred CDN-guided synthesis of g1 or g2. Similarly, the triggered reconfigured CDNs are subjected to two hairpins HC and HD, the templates I'/I and J'/J, and the RNA polymerase (RNAp)/NTPs machinery. While the cleavage of the hairpins by the constituents associated with the parent CDN leads to the transcription of the broccoli aptamer recognizing the DFHBI ligand and of the aptamer recognizing the malachite green (MG) ligand, the orthogonally triggered CDNs lead to the CDNs-guided enhanced transcription of either the DFHBI aptamer or the MG aptamer. In addition, subjecting the triggered reconfigured CDNs to predesigned hairpins HE and HF, the templates M'/M and N'/N, the RNAp/NTPs machinery, and the cell-free ribosome t-RNA machinery leads to the CDNs-guided transcription/translation of the green fluorescence protein (GFP) or red fluorescence protein (RFP).

Viruses are efficient metabolic engineers that actively rewire host metabolic pathways to support their lifecycle. Charting SARS-CoV-2 induced metabolic changes in lung cells could offer insight into COVID-19 pathogenesis while presenting new therapeutic targets. Here we show that the transcriptional response SARS-CoV-2 in primary lung epithelial cells and biopsies of COVID-19 patients is predominantly metabolic. This transcriptional signature was dominated by changes to lipid metabolism and the induction of IRE1 and PKR pathways of endoplasmic stress in a process regulated by several viral proteins. Transcriptional regulatory analysis of these changes reveals small clusters of transcription factors modulating key enzymes in each pathway. The upregulation of glycolysis and the dysregulation of the citric acid cycle was mediated by NFκB and RELA. While the upregulation of fatty acid and cholesterol synthesis showed a more complex control conditionally modulated by ER-stress activated PPARγ, C/EBP, and PPARα. Viral protein ORF3a appeared to interact with all three pathways suggesting both direct and indirect modulation of host metabolism. Finally, we show that PPARα-agonist fenofibrate reversed the metabolic changes induced by SARS-CoV-2 blocking viral replication. Taken together, our data suggest that elevated lipid metabolism may underlie aspects of COVID-19 pathogenesis, offering new therapeutic avenues in targeting this critical pathway on which the virus relies.Funding: Funding was provided by European Research Council Consolidator Grants OCLD (project no. 681870) and generous gifts from the Nikoh Foundation and the Sam and Rina Frankel Foundation (YN). This work was additionally funded by generous support from the Marc Haas Foundation, the National Institutes of Health, and DARPA's PREPARE Program (HR0011-20-2-0040). The views, opinions, and/or findings expressed are those of the author and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. government (BRT). Ethical Approval: Experiments using samples from human subjects were conducted in accordance with local regulations and with the approval of the institutional review board at the Icahn School of Medicine at Mount Sinai under protocol HS#12-00145.

The enzymes glucose oxidase (GOx), acetylcholine esterase (AchE) and urease that drive biocatalytic transformations to alter pH, are integrated into pH-responsive DNA-based hydrogels. A two-enzyme-loaded hydrogel composed of GOx/urease or AchE/urease and a three-enzyme-loaded hydrogel composed of GOx/AchE/urease are presented. The biocatalytic transformations within the hydrogels lead to the dictated reconfiguration of nucleic acid bridges and the switchable control over the stiffness of the respective hydrogels. The switchable stiffness features are used to develop biocatalytically guided shape-memory and self-healing matrices. In addition, loading of GOx/insulin in a pH-responsive DNA-based hydrogel yields a glucose-triggered matrix for the controlled release of insulin, acting as an artificial pancreas. The release of insulin is controlled by the concentrations of glucose, hence, the biocatalytic insulin-loaded hydrogel provides an interesting sense-and-treat carrier for controlling diabetes.

The liver is the central hub of xenobiotic metabolism and consequently the organ most prone to cosmetic- and drug-induced toxicity. Failure to detect liver toxicity or to assess compound clearance during product development is a major cause of postmarketing product withdrawal, with disastrous clinical and financial consequences. While small animals are still the preferred model in drug development, the recent ban on animal use in the European Union created a pressing need to develop precise and efficient tools to detect human liver toxicity during cosmetic development. This article includes a brief review of liver development, organization, and function and focuses on the state of the art of long-term cell culture, including hepatocyte cell sources, heterotypic cell-cell interactions, oxygen demands, and culture medium formulation. Finally, the article reviews emerging liver-on-chip devices and discusses the advantages and pitfalls of individual designs. The goal of this review is to provide a framework to design liver-on-chip devices and criteria with which to evaluate this emerging technology.

Drug development is currently hampered by the inability of animal experiments to accurately predict human response. While emerging organ on chip technology offers to reduce risk using microfluidic models of human tissues, the technology still mostly relies on end-point assays and biomarker measurements to assess tissue damage resulting in limited mechanistic information and difficulties to detect adverse effects occurring below the threshold of cellular damage. Here we present a sensor-integrated liver on chip array in which oxygen is monitored using two-frequency phase modulation of tissue-embedded microprobes, while glucose, lactate and temperature are measured in real time using microfluidic electrochemical sensors. Our microphysiological platform permits the calculation of dynamic changes in metabolic fluxes around central carbon metabolism, producing a unique metabolic fingerprint of the liver's response to stimuli. Using our platform, we studied the dynamics of human liver response to the epilepsy drug Valproate (Depakine™) and the antiretroviral medication Stavudine (Zerit™). Using E6/E7LOW hepatocytes, we show TC50 of 2.5 and 0.8 mM, respectively, coupled with a significant induction of steatosis in 2D and 3D cultures. Time to onset analysis showed slow progressive damage starting only 15-20 hours post-exposure. However, flux analysis showed a rapid disruption of metabolic homeostasis occurring below the threshold of cellular damage. While Valproate exposure led to a sustained 15% increase in lipogenesis followed by mitochondrial stress, Stavudine exposure showed only a transient increase in lipogenesis suggesting disruption of β-oxidation. Our data demonstrates the importance of tracking metabolic stress as a predictor of clinical outcome.