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Competing Interests: Competing interests The author declares no competing interests.

Geometric and structural integrity often deteriorate in 3D printed cell-laden constructs over time due to cellular compaction and hydrogel shrinkage. This study introduces a new approach that synergizes the advantages of cell compatibility of biological hydrogels and mechanical stability of elastomeric polymers for structure fidelity maintenance upon stereolithography and extrusion 3D printing. Enabling this advance is the composite bioink, formulated by integrating elastomeric microparticles from poly(octamethylene maleate (anhydride) citrate) (POMaC) into biologically derived hydrogels (fibrin, gelatin methacryloyl (GelMA), and alginate). The composite bioink enhanced the elasticity and plasticity of the 3D printed constructs, effectively mitigating tissue compaction and swelling. It exhibited a low shear modulus and a rapid crosslinking time, along with a high ultimate compressive strength and resistance to deformation from cellular forces and physical handling; this was attributed to packing and stress dissipation of elastomeric particles, which was confirmed via mathematical modelling. Enhanced functional assembly and stability of human iPSC-derived cardiac tissues and primary vasculature proved the utility of the composite bioink in tissue engineering. In vivo implantation studies revealed that constructs containing POMaC particles exhibited improved resilience against host tissue stress, enhanced angiogenesis, and infiltration of pro-reparative macrophages., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Milica Radisic reports financial support was provided by National Institutes of Health Grant 2R01 HL076485. Milica Radisic reports financial support was provided by Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant (RGPIN 326982-10). Milica Radisic reports financial support was provided by NSERC Strategic Grant (STPGP 506689-17). Milica Radisic reports financial support was provided by Canadian Institutes of Health Research (CIHR) Foundation Grant FDN-167274. Milica Radisic reports financial support was provided by Canada Research Chairs and Killam Fellowship. Shira Landau reports financial support was provided by Rothschild Fellowship. Shira Landau reports financial support was provided by EMBO ALTF 530–2022. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide with numerous inflammatory cell etiologies associated with impaired cardiac function and heart failure. Inflammatory cardiomyopathy, also known as myocarditis, is an acquired cardiomyopathy characterized by inflammatory cell infiltration into the myocardium with a high risk of progression to deteriorated cardiac function. Recently, amidst the ongoing COVID-19 pandemic, the emergence of acute myocarditis as a complication of SARS-CoV-2 has garnered significant concern. Given its mechanisms remain elusive in conjunction with the recent withdrawal of previously FDA-approved antiviral therapeutics and prophylactics due to unexpected cardiotoxicity, there is a pressing need for human-mimetic platforms to investigate disease pathogenesis, model dysfunctional features, and support pre-clinical drug screening. Traditional in vitro models for studying cardiovascular diseases have inherent limitations in recapitulating the complexity of the in vivo microenvironment. Heart-on-a-chip technologies, combining microfabrication, microfluidics, and tissue engineering techniques, have emerged as a promising approach for modeling inflammatory cardiac diseases like myocarditis. This review outlines the established and emerging conditions of inflamed myocardium, identifying key features essential for recapitulating inflamed myocardial structure and functions in heart-on-a-chip models, highlighting recent advancements, including the integration of anisotropic contractile geometry, cardiomyocyte maturity, electromechanical functions, vascularization, circulating immunity, and patient/sex specificity. Finally, we discuss the limitations and future perspectives necessary for the clinical translation of these advanced technologies., Competing Interests: A.P., M.H.C.L., A.S., and R.K. have no conflicts to disclose. M.R. is an inventor on an issued US patent for Biowire technology that is licensed to Valo Health; she receives royalties for this invention., (© 2024 Author(s).)

Competing Interests: Declaration of interests M.R. is an inventor in multiple patents covering Biowire heart-on-a-chip technology that are licensed to Valo Health. She receives royalty from these inventions. M.R. holds equity in and receives consulting fees from Quthero, Inc. She is an inventor on patents and patent applications describing regenerative peptides and biomaterials that have been licensed to Quthero, Inc. D.D.H. is a founder of Vivodyne, Inc., and holds equity in Vivodyne, Inc., and Emulate Bio, Inc. D.D.H. has a number of patent applications and issued patents related to in vitro models of human tissue. M.H. is an inventor on several patents related to organoid work. J.B. is an inventor on a patent related to organoid technology, has received consultation fees, and is principal investigator on an industry-sponsored project related to the work (Proteostasis, Eloxx Pharmaceuticals). He cofounded and has shares <5% in FAIR Therapeutics. Full disclosures can be found at https://www.umcutrecht.nl/en/research/researchers/beekman-jeffrey-jm.

The fabrication of complex and stable vasculature in engineered cardiac tissues represents a significant hurdle towards building physiologically relevant models of the heart. Here, we implemented a 3D model of cardiac vasculogenesis, incorporating endothelial cells (EC), stromal cells, and human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CM) in a fibrin hydrogel. The presence of CMs disrupted vessel formation in 3D tissues, resulting in the upregulation of endothelial activation markers and altered extracellular vesicle (EV) signaling in engineered tissues as determined by the proteomic analysis of culture supernatant. miRNA sequencing of CM- and EC-secreted EVs highlighted key EV-miRNAs that were postulated to play differing roles in cardiac vasculogenesis, including the let-7 family and miR-126-3p in EC-EVs. In the absence of CMs, the supplementation of CM-EVs to EC monolayers attenuated EC migration and proliferation and resulted in shorter and more discontinuous self-assembling vessels when applied to 3D vascular tissues. In contrast, supplementation of EC-EVs to the tissue culture media of 3D vascularized cardiac tissues mitigated some of the deleterious effects of CMs on vascular self-assembly, enhancing the average length and continuity of vessel tubes that formed in the presence of CMs. Direct transfection validated the effects of the key EC-EV miRNAs let-7b-5p and miR-126-3p in improving the maintenance of continuous vascular networks. EC-EV supplementation to biofabricated cardiac tissues and microfluidic devices resulted in tissue vascularization, illustrating the use of this approach in the engineering of enhanced, perfusable, microfluidic models of the myocardium., (Creative Commons Attribution license.)

It is said that all models are wrong, but some are useful. In vitro human cell-based models are a prime example of this maxim. We asked researchers: when is your model system useful? How can it be made more useful? What are its limitations?, Competing Interests: Declaration of interests M.R. is an inventor in multiple patents covering Biowire heart-on-a-chip technology that are licensed to Valo Health. She receives royalty from these inventions. M.R. holds equity in and receives consulting fees from Quthero, Inc. She is an inventor on patents and patent applications describing regenerative peptides and biomaterials that have been licensed to Quthero, Inc. D.D.H. is a founder of Vivodyne, Inc., and holds equity in Vivodyne, Inc., and Emulate Bio, Inc. D.D.H. has a number of patent applications and issued patents related to in vitro models of human tissue. M.H. is an inventor on several patents related to organoid work. J.B. is an inventor on a patent related to organoid technology, has received consultation fees, and is principal investigator on an industry-sponsored project related to the work (Proteostasis, Eloxx Pharmaceuticals). He cofounded and has shares <5% in FAIR Therapeutics. Full disclosures can be found at https://www.umcutrecht.nl/en/research/researchers/beekman-jeffrey-jm., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The intricate anatomical structure and high cellular density of the myocardium complicate the bioengineering of perfusable vascular networks within cardiac tissues. In vivo neonatal studies highlight the key role of resident cardiac macrophages in post-injury regeneration and angiogenesis. Here, we integrate human pluripotent stem-cell-derived primitive yolk-sac-like macrophages within vascularized heart-on-chip platforms. Macrophage incorporation profoundly impacted the functionality and perfusability of microvascularized cardiac tissues up to 2 weeks of culture. Macrophages mitigated tissue cytotoxicity and the release of cell-free mitochondrial DNA (mtDNA), while upregulating the secretion of pro-angiogenic, matrix remodeling, and cardioprotective cytokines. Bulk RNA sequencing (RNA-seq) revealed an upregulation of cardiac maturation and angiogenesis genes. Further, single-nuclei RNA sequencing (snRNA-seq) and secretome data suggest that macrophages may prime stromal cells for vascular development by inducing insulin like growth factor binding protein 7 (IGFBP7) and hepatocyte growth factor (HGF) expression. Our results underscore the vital role of primitive macrophages in the long-term vascularization of cardiac tissues, offering insights for therapy and advancing heart-on-a-chip technologies., Competing Interests: Declaration of interests M.R. and Y.Z. are inventors on an issued patent that describes Biowire technology. This patent is licensed to Valo Health. M.R. and Y.Z. receive licensing revenue., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Epicardial cells (EPIs) form the outer layer of the heart and play an important role in development and disease. Current heart-on-a-chip platforms still do not fully mimic the native cardiac environment due to the absence of relevant cell types, such as EPIs. Here, using the Biowire II platform, engineered cardiac tissues with an epicardial outer layer and inner myocardial structure are constructed, and an image analysis approach is developed to track the EPI cell migration in a beating myocardial environment. Functional properties of EPI cardiac tissues improve over two weeks in culture. In conditions mimicking ischemia reperfusion injury (IRI), the EPI cardiac tissues experience less cell death and a lower impact on functional properties. EPI cell coverage is significantly reduced and more diffuse under normoxic conditions compared to the post-IRI conditions. Upon IRI, migration of EPI cells into the cardiac tissue interior is observed, with contributions to alpha smooth muscle actin positive cell population. Altogether, a novel heart-on-a-chip model is designed to incorporate EPIs through a formation process that mimics cardiac development, and this work demonstrates that EPI cardiac tissues respond to injury differently than epicardium-free controls, highlighting the importance of including EPIs in heart-on-a-chip constructs that aim to accurately mimic the cardiac environment., (© 2024 The Authors. Advanced Healthcare Materials published by Wiley‐VCH GmbH.)

Biofabrication technologies hold the potential to provide high-throughput, easy-to-operate, and cost-effective systems that recapitulate complexities of the native heart. The size of the fabricated model, printing resolution, biocompatibility, and ease-of-fabrication are some of the major parameters that can be improved to develop more sophisticated cardiac models. Here, we review recent cardiac engineering technologies ranging from microscaled organoids, millimeter-scaled heart-on-a-chip platforms, in vitro ventricle models sized to the fetal heart, larger cardiac patches seeded with billions of cells, and associated biofabrication technologies used to produce these models. Finally, advancements that facilitate model translation are discussed, such as their application as carriers for bioactive components and cells in vivo or their capability for drug testing and disease modeling in vitro., Competing Interests: Declaration of Competing Interest Editorial declaration: M.R. is an Associate Editor of ACS Biomaterial Science & Engineering, Reviewing Editor for eLife, Consulting Editor for Journal of Molecular and Cellular Cardiology, Editorial Board of Tissue Engineering, Advanced Drug Delivery, Advanced Biosystems and Regenerative Biomaterials and was not involved in the editorial review or the decision to publish this article. The authors declare the following financial interests/personal relationships, which may be considered as potential competing interests: M.R. and Y.Z. are inventors on an issued US patent for Biowire technology that is licensed to Valo Health; they receive royalties for this invention. M.R. is supported by the Killam Fellowship and is a Canada Research Chair. S.O. is supported by a CIHR Canada Graduate Scholarship. Y.Z. and R.K. are supported by a CIHR Postdoctoral Fellowship., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Adverse cardiac outcomes in COVID-19 patients, particularly those with preexisting cardiac disease, motivate the development of human cell-based organ-on-a-chip models to recapitulate cardiac injury and dysfunction and for screening of cardioprotective therapeutics. Here, we developed a heart-on-a-chip model to study the pathogenesis of SARS-CoV-2 in healthy myocardium established from human induced pluripotent stem cell (iPSC)-derived cardiomyocytes and a cardiac dysfunction model, mimicking aspects of preexisting hypertensive disease induced by angiotensin II (Ang II). We recapitulated cytopathic features of SARS-CoV-2-induced cardiac damage, including progressively impaired contractile function and calcium handling, apoptosis, and sarcomere disarray. SARS-CoV-2 presence in Ang II-treated hearts-on-a-chip decreased contractile force with earlier onset of contractile dysfunction and profoundly enhanced inflammatory cytokines compared to SARS-CoV-2 alone. Toward the development of potential therapeutics, we evaluated the cardioprotective effects of extracellular vesicles (EVs) from human iPSC which alleviated the impairment of contractile force, decreased apoptosis, reduced the disruption of sarcomeric proteins, and enhanced beta-oxidation gene expression. Viral load was not affected by either Ang II or EV treatment. We identified MicroRNAs miR-20a-5p and miR-19a-3p as potential mediators of cardioprotective effects of these EVs., Competing Interests: Competing interests statement:Y.Z., G.V.-N., B.Z., and M.R. are inventors on patents for cardiac tissue cultivation that are licensed to Valo Health. Q.W., Y.Z., and M.R. have a filed patent application on thermoplastic polymer composition for micro 3D printing and uses thereof. B.Z. holds equity in OrganoBiotech.

Mitochondrial transplantation and transfer are being explored as therapeutic options in acute and chronic diseases to restore cellular function in injured tissues. To limit potential immune responses and rejection of donor mitochondria, current clinical applications have focused on delivery of autologous mitochondria. We recently convened a Mitochondrial Transplant Convergent Working Group (CWG), to explore three key issues that limit clinical translation: (1) storage of mitochondria, (2) biomaterials to enhance mitochondrial uptake, and (3) dynamic models to mimic the complex recipient tissue environment. In this review, we present a summary of CWG conclusions related to these three issues and provide an overview of pre-clinical studies aimed at building a more robust toolkit for translational trials., (© 2024. The Author(s).)

Pathogenic variants in MYH7 and MYBPC3 account for the majority of hypertrophic cardiomyopathy (HCM). Targeted drugs like myosin ATPase inhibitors have not been evaluated in children. We generate patient and variant-corrected iPSC-cardiomyocytes (CMs) from pediatric HCM patients harboring single variants in MYH7 (V606M; R453C), MYBPC3 (G148R) or digenic variants (MYBPC3 P955fs, TNNI3 A157V). We also generate CMs harboring MYBPC3 mono- and biallelic variants using CRISPR editing of a healthy control. Compared with isogenic and healthy controls, variant-positive CMs show sarcomere disorganization, higher contractility, calcium transients, and ATPase activity. However, only MYH7 and biallelic MYBPC3 variant-positive CMs show stronger myosin-actin binding. Targeted myosin ATPase inhibitors show complete rescue of the phenotype in variant-positive CMs and in cardiac Biowires to mirror isogenic controls. The response is superior to verapamil or metoprolol. Myosin inhibitors can be effective in genotypically diverse HCM highlighting the need for myosin inhibitor drug trials in pediatric HCM., Competing Interests: Declaration of interests S.M. is a consultant for Bristol Myers Squibb and Tenaya Therapeutics. M.R. and Y.Z. are inventors on an issued US patent covering Biowire tissue fabrication. They receive royalties from Valo Health. M.R. has a consulting agreement with Valo Health and had a consulting agreement with Tenaya Therapeutics. M.R. and Y.Z. are co-founders of TARA Biosystems Inc. and held equity in the company until April 2022., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Yolk sac macrophages are the first to seed the developing heart, however we have no understanding of their roles in human heart development and function due to a lack of accessible tissue. Here, we bridge this gap by differentiating human embryonic stem cells (hESCs) into primitive LYVE1 + macrophages (hESC-macrophages) that stably engraft within contractile cardiac microtissues composed of hESC-cardiomyocytes and fibroblasts. Engraftment induces a human fetal cardiac macrophage gene program enriched in efferocytic pathways. Functionally, hESC-macrophages trigger cardiomyocyte sarcomeric protein maturation, enhance contractile force and improve relaxation kinetics. Mechanistically, hESC-macrophages engage in phosphatidylserine dependent ingestion of apoptotic cardiomyocyte cargo, which reduces microtissue stress, leading hESC-cardiomyocytes to more closely resemble early human fetal ventricular cardiomyocytes, both transcriptionally and metabolically. Inhibiting hESC-macrophage efferocytosis impairs sarcomeric protein maturation and reduces cardiac microtissue function. Taken together, macrophage-engineered human cardiac microtissues represent a considerably improved model for human heart development, and reveal a major beneficial role for human primitive macrophages in enhancing early cardiac tissue function., Competing Interests: Competing interests M. R. and Y.Z. are inventors on patents for cardiac tissue cultivation that are licensed to Valo Health. They receive licensing royalty from this invention. Q.W., M.R., and Y.Z. have a filed patent application on thermoplastic polymer composition for micro 3D printing and uses thereof. All other authors declare no competing interests.

Artificial organs and organs-on-a-chip (OoC) are of great clinical and scientific interest and have recently been made by additive manufacturing, but depend on, and benefit from, biocompatible, biodegradable, and soft materials. Poly(octamethylene maleate (anhydride) citrate (POMaC) meets these criteria and has gained popularity, and as in principle, it can be photocured and is amenable to vat-photopolymerization (VP) 3D printing, but only low-resolution structures have been produced so far. Here, a VP-POMaC ink is introduced and 3D printing of 80 µm positive features and complex 3D structures is demonstrated using low-cost (≈US$300) liquid-crystal display (LCD) printers. The ink includes POMaC, a diluent and porogen additive to reduce viscosity within the range of VP, and a crosslinker to speed up reaction kinetics. The mechanical properties of the cured ink are tuned to match the elastic moduli of different tissues simply by varying the porogen concentration. The biocompatibility is assessed by cell culture which yielded 80% viability and the potential for tissue engineering illustrated with a 3D-printed gyroid seeded with cells. VP-POMaC and low-cost LCD printers make the additive manufacturing of high resolution, elastomeric, and biodegradable constructs widely accessible, paving the way for a myriad of applications in tissue engineering and 3D cell culture as demonstrated here, and possibly in OoC, implants, wearables, and soft robotics., (© 2023 The Authors. Advanced Healthcare Materials published by Wiley‐VCH GmbH.)

Recent advances in both cardiac tissue engineering and hearts-on-a-chip are grounded in new biomaterial development as well as the employment of innovative fabrication techniques that enable precise control of the mechanical, electrical, and structural properties of the cardiac tissues being modelled. The elongated structure of cardiomyocytes requires tuning of substrate properties and application of biophysical stimuli to drive its mature phenotype. Landmark advances have already been achieved with induced pluripotent stem cell-derived cardiac patches that advanced to human testing. Heart-on-a-chip platforms are now commonly used by a number of pharmaceutical and biotechnology companies. Here, we provide an overview of cardiac physiology in order to better define the requirements for functional tissue recapitulation. We then discuss the biomaterials most commonly used in both cardiac tissue engineering and heart-on-a-chip, followed by the discussion of recent representative studies in both fields. We outline significant challenges common to both fields, specifically: scalable tissue fabrication and platform standardization, improving cellular fidelity through effective tissue vascularization, achieving adult tissue maturation, and ultimately developing cryopreservation protocols so that the tissues are available off the shelf., (© 2023 The Authors. Journal of Biomedical Materials Research Part A published by Wiley Periodicals LLC.)

Despite tremendous progress in the development of mature heart-on-a-chip models, human cell-based models of myocardial inflammation are lacking. Here, we bioengineered a vascularized heart-on-a-chip with circulating immune cells to model severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced acute myocarditis. We observed hallmarks of coronavirus disease (COVID-19)-induced myocardial inflammation, as the presence of immune cells augmented the secretion of proinflammatory cytokines, triggered progressive impairment of contractile function, and altered intracellular calcium transients. An elevation of circulating cell-free mitochondrial DNA (ccf-mtDNA) was measured first in the heart-on-a-chip and then validated in COVID-19 patients with low left ventricular ejection fraction, demonstrating that mitochondrial damage is an important pathophysiological hallmark of inflammation-induced cardiac dysfunction. Leveraging this platform in the context of SARS-CoV-2-induced myocardial inflammation, we established that administration of endothelial cell-derived exosomes effectively rescued the contractile deficit, normalized calcium handling, elevated the contraction force, and reduced the ccf-mtDNA and cytokine release via Toll-like receptor-nuclear factor κB signaling axis.

The substantial economic impact of non-healing wounds, scarring, and burns stemming from skin injuries is evident, resulting in a financial burden on both patients and the healthcare system. This review paper provides an overview of the skin's vital role in guarding against various environmental challenges as the body's largest protective organ and associated developments in biomaterials for wound healing. We first introduce the composition of skin tissue and the intricate processes of wound healing, with special attention to the crucial role of immunomodulation in both acute and chronic wounds. This highlights how the imbalance in the immune response, particularly in chronic wounds associated with underlying health conditions such as diabetes and immunosuppression, hinders normal healing stages. Then, this review distinguishes between traditional wound-healing strategies that create an optimal microenvironment and recent peptide-based biomaterials that modulate cellular processes and immune responses to facilitate wound closure. Additionally, we highlight the importance of considering the stages of wounds in the healing process. By integrating advanced materials engineering with an in-depth understanding of wound biology, this approach holds promise for reshaping the field of wound management and ultimately offering improved outcomes for patients with acute and chronic wounds., (© The Author(s) 2024. Published by Oxford University Press.)

H9c2 myoblasts are a cell line derived from embryonic rat heart tissue and demonstrate the ability to differentiate to cardiac myotubes upon reduction of the serum concentration (from 10% to 1%) and addition of all-trans retinoic acid in the growth medium. H9c2 cells are increasingly being used as an easy-to-culture proxy for some functions of cardiomyocytes. The cryobiology of cardiac cells including H9c2 myoblasts has not been studied as extensively as that of some cell types. Consequently, it is important to characterize the cryobiological response and systematically develop well-optimized cryopreservation protocols for H9c2 cells to have optimal and consistent viability and functionality after thaw for high quality studies with this cell type. In this work, an interrupted slow cooling protocol (graded freezing) was applied to characterize H9c2 response throughout the cooling profile. Important factors that affect the cell response were examined, and final protocols that provided the highest post-thaw viability are reported. One protocol uses the common cryoprotectant dimethyl sulfoxide combined with hydroxyethyl starch, which will be suitable for applications in which the presence of dimethyl sulfoxide is not an issue; and the other protocol uses glycerol as a substitute when there is a desire to avoid dimethyl sulfoxide. Both protocols achieved comparable post-thaw viabilities (higher than 80%) based on SYTO 13/GelRed flow cytometry results. H9c2 cells cryopreserved by either protocol showed ability to differentiate to cardiac myotubes comparable to fresh (unfrozen) H9c2 cells, and their differentiation to cardiac myotubes was confirmed with i) change in cell morphology, ii) expression of cardiac marker troponin I, and iii) increase in mitochondrial mass., Competing Interests: M. Radisic has an issued patent covering Biowire cardiac tissue fabrication that is licensed to Valo Health. MR receives licensing income from this patent., (Copyright: © 2024 Ashrafi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Aims: Adiponectin has been shown to mediate cardioprotective effects and levels are typically reduced in patients with cardiometabolic disease. Hence, there has been intense interest in developing adiponectin-based therapeutics. The aim of this translational research study was to examine the functional significance of targeting adiponectin signaling with the adiponectin receptor agonist ALY688 in a mouse model of heart failure with reduced ejection fraction (HFrEF), and the mechanisms of cardiac remodeling leading to cardioprotection., Methods and Results: Wild-type mice were subjected to transverse aortic constriction (TAC) to induce left ventricular pressure overload (PO), or sham surgery, with or without daily subcutaneous ALY688-SR administration. Temporal analysis of cardiac function was conducted via weekly echocardiography for 5 weeks and we observed that ALY688 attenuated the PO-induced dysfunction. ALY688 also reduced cardiac hypertrophic remodeling, assessed via LV mass, heart weight to body weight ratio, cardiomyocyte cross sectional area, ANP and BNP levels. ALY688 also attenuated PO-induced changes in myosin light and heavy chain expression. Collagen content and myofibroblast profile indicated that fibrosis was attenuated by ALY688 with TIMP1 and scleraxis/periostin identified as potential mechanistic contributors. ALY688 reduced PO-induced elevation in circulating cytokines including IL-5, IL-13 and IL-17, and the chemoattractants MCP-1, MIP-1β, MIP-1alpha and MIP-3α. Assessment of myocardial transcript levels indicated that ALY688 suppressed PO-induced elevations in IL-6, TLR-4 and IL-1β, collectively indicating anti-inflammatory effects. Targeted metabolomic profiling indicated that ALY688 increased fatty acid mobilization and oxidation, increased betaine and putrescine plus decreased sphingomyelin and lysophospholipids, a profile indicative of improved insulin sensitivity., Conclusion: These results indicate that the adiponectin mimetic peptide ALY688 reduced PO-induced fibrosis, hypertrophy, inflammation and metabolic dysfunction and represents a promising therapeutic approach for treating HFrEF in a clinical setting., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: HHH is the CEO and GS and AAS act as consultants for Allysta Pharmaceuticals Inc. MR and YZ are inventors on a patent licenced to Valo Health and are receiving licencing revenue from this invention., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Cell-based models that mimic in vivo heart physiology are poised to make significant advances in cardiac disease modeling and drug discovery. In these systems, cardiomyocyte (CM) contractility is an important functional metric, but current measurement methods are inaccurate and low-throughput or require complex setups. To address this need, we developed a standalone noninvasive, label-free ultrasound technique operating at 40-200 MHz to measure the contractile kinetics of cardiac models, ranging from single adult CMs to 3D microtissue constructs in standard cell culture formats. The high temporal resolution of 1000 fps resolved the beat profile of single mouse CMs paced at up to 9 Hz, revealing limitations of lower speed optical based measurements to resolve beat kinetics or characterize aberrant beats. Coupling of ultrasound with traction force microscopy enabled the measurement of the CM longitudinal modulus and facile estimation of adult mouse CM contractile forces of 2.34 ± 1.40 μN, comparable to more complex measurement techniques. Similarly, the beat rate, rhythm, and drug responses of CM spheroid and microtissue models were measured, including in configurations without optical access. In conclusion, ultrasound can be used for the rapid characterization of CM contractile function in a wide range of commonly studied configurations ranging from single cells to 3D tissue constructs using standard well plates and custom microdevices, with applications in cardiac drug discovery and cardiotoxicity evaluation.