transplantation-3d-bioprinted-patch-murine-model-myocardial

Transplantation of a 3D Bioprinted Patch in a Murine Model of Myocardial Infarction

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ...

cardiac-spheroids-as-vitro-bioengineered-heart-tissues-to-study-human

Cardiac Spheroids as in vitro Bioengineered Heart Tissues to Study Human Heart Pathophysiology

Despite several advances in cardiac tissue engineering, one of the major challenges to overcome remains the generation of a fully functional vascular ...

The University of Sydney

University of Technology Sydney (UTS)

The Royal North Shore Hospital

University of Sydney

Royal North Shore Hospital

University of Technology, Sydney

Glutathionylation of endothelial nitric oxide synthase (eNOS) "uncouples" the enzyme, switching its function from nitric oxide (NO) to O2(•-) generation. We examined whether this reversible redox modification plays a role in angiotensin II (Ang II)-induced endothelial dysfunction.

Glutathionylation mediates angiotensin II-induced eNOS uncoupling, amplifying NADPH oxidase-dependent endothelial dysfunction.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has the ability to inhibit angiogenesis by inducing endothelial cell death, as well as being able to promote pro-angiogenic activity in vitro. These seemingly opposite effects make its role in ischemic disease unclear. Using Trail(-/-) and wildtype mice, we sought to determine the role of TRAIL in angiogenesis and neovascularization following hindlimb ischemia.

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) Promotes Angiogenesis and Ischemia-Induced Neovascularization Via NADPH Oxidase 4 (NOX4) and Nitric Oxide-Dependent Mechanisms.

Perturbed balance between NO and O2 (•-). (ie, NO/redox imbalance) is central in the pathobiology of diabetes-induced vascular dysfunction. We examined whether stimulation of β3 adrenergic receptors (β3 ARs), coupled to endothelial nitric oxide synthase (eNOS) activation, would re-establish NO/redox balance, relieve oxidative inhibition of the membrane proteins eNOS and Na(+)-K(+) (NK) pump, and improve vascular function in a new animal model of hyperglycemia.

β3 Adrenergic Stimulation Restores Nitric Oxide/Redox Balance and Enhances Endothelial Function in Hyperglycemia.

Three-dimensional in vitro cell systems are a promising alternative to animals to study cardiac biology and disease. We have generated three-dimensional in vitro models of the human heart ("cardiac spheroids", CSs) by co-culturing human primary or iPSC-derived cardiomyocytes, endothelial cells and fibroblasts at ratios approximating those present in vivo. The cellular organisation, extracellular matrix and microvascular network mimic human heart tissue. These spheroids have been employed to investigate the dose-limiting cardiotoxicity of the common anti-cancer drug doxorubicin. Viability/cytotoxicity assays indicate dose-dependent cytotoxic effects, which are inhibited by the nitric oxide synthase (NOS) inhibitor L-NIO, and genetic inhibition of endothelial NOS, implicating peroxynitrous acid as a key damaging agent. These data indicate that CSs mimic important features of human heart morphology, biochemistry and pharmacology in vitro, offering a promising alternative to animals and standard cell cultures with regard to mechanistic insights and prediction of toxic effects in human heart tissue.

Cardiac spheroids as promising in vitro models to study the human heart microenvironment.

Spheroid cultures are among the most explored cellular biomaterials used in cardiovascular research, due to their improved integration of biochemical and physiological features of the heart in a defined architectural three-dimensional microenvironment when compared to monolayer cultures. To further explore the potential use of spheroid cultures for research, we engineered a novel in vitro model of the heart with vascularized cardiac spheroids (VCSs), by coculturing cardiac myocytes, endothelial cells, and fibroblasts isolated from dissociated rat neonatal hearts (aged 1-3 days) in hanging drop cultures. To evaluate the validity of VCSs in recapitulating pathophysiological processes typical of the in vivo heart, such as cardiac fibrosis, we then treated VCSs with transforming growth factor beta 1 (TGFβ1), a known profibrotic agent. Our mRNA analysis demonstrated that TGFβ1-treated VCSs present elevated levels of expression of connective tissue growth factor, fibronectin, and TGFβ1 when compared to control cultures. We demonstrated a dramatic increase in collagen deposition following TGFβ1 treatment in VCSs in the PicroSirius Red-stained sections. Doxorubicin, a renowned cardiotoxic and profibrotic agent, triggered apoptosis and disrupted vascular networks in VCSs. Taken together, our findings demonstrate that VCSs are a valid model for the study of the mechanisms involved in cardiac fibrosis, with the potential to be used to investigate novel mechanisms and therapeutics for treating and preventing cardiac fibrosis in vitro.

Vascularized Cardiac Spheroids as Novel 3D in vitro Models to Study Cardiac Fibrosis.

Functionalized poly(ethylene dioxythiophene) (f-PEDOT) was copolymerized with two vinyl monomers of different hydrophilicity, acrylic acid and hydroxyethyl methacrylate, to produce electroconductive hydrogels with a range of physical and electronic properties. These hydrogels not only possessed tailored physical properties, such as swelling ratios and mechanical properties, but also displayed electroactivity dependent on the chemical composition of the network. Raman spectroscopy indicated that the functional PEDOT in the hydrogels is in an oxidized form, most likely accounting for the good electrochemical response of the hydrogels observed in physiological buffer. In vitro cell studies showed that cardiac cells respond differently when seeded on hydrogel substrates with different compositions. This study presents a facile approach for the fabrication of electroconductive hydrogels with a range of properties, paving the way for scaffolds that can meet the requirements of different electroresponsive tissues.

Versatile Fabrication Approach of Conductive Hydrogels via Copolymerization with Vinyl Monomers.

The stem cell microenvironment or niche plays a critical role in the regulation of survival, differentiation and behavior of stem cells and their progenies. Recapitulating each aspect of the stem cell niche is therefore essential for their optimal use in in vitro studies and in vivo as future therapeutics in humans. Engineering of optimal conditions for three-dimensional stem cell culture includes multiple transient and dynamic physiological stimuli, such as blood flow and tissue stiffness. Bioprinting and microfluidics technologies, including organs-on-a-chip, are among the most recent approaches utilized to replicate the three-dimensional stem cell niche for human tissue fabrication that allow the integration of multiple levels of tissue complexity, including blood flow. This chapter focuses on the physico-chemical and genetic cues utilized to engineer the stem cell niche and provides an overview on how both bioprinting and microfluidics technologies are improving our knowledge in this field for both disease modeling and tissue regeneration, including drug discovery and toxicity high-throughput assays and stem cell-based therapies in humans.

Current Technologies Based on the Knowledge of the Stem Cells Microenvironments.

Our laboratory has recently developed a novel three-dimensional in vitro model of the human heart, which we call the vascularized cardiac spheroid (VCS). These better recapitulate the human heart's cellular and extracellular microenvironment compared to the existing in vitro models. To achieve this, human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes, cardiac fibroblasts, and human coronary artery endothelial cells are co-cultured in hanging drop culture in ratios similar to those found in the human heart in vivo. The resulting three-dimensional cellular organization, extracellular matrix, and microvascular network formation throughout the VCS has been shown to mimic the one present in the human heart tissue. Therefore, VCSs offer a promising platform to study cardiac physiology, disease, and pharmacology, as well as bioengineering constructs to regenerate heart tissue.

Stem Cell-Derived Cardiac Spheroids as 3D In Vitro Models of the Human Heart Microenvironment.

Previous attempts in cardiac bioengineering have failed to provide tissues for cardiac regeneration. Recent advances in 3-dimensional bioprinting technology using prevascularized myocardial microtissues as 'bioink' have provided a promising way forward. This review guides the reader to understand why myocardial tissue engineering is difficult to achieve and how revascularization and contractile function could be restored in 3-dimensional bioprinted heart tissue using patient-derived stem cells.

Current challenges in three-dimensional bioprinting heart tissues for cardiac surgery.

Preclinical in vivo studies using omental tissue as a biomaterial for myocardial regeneration are promising and have not previously been collated. We aimed to evaluate the effects of the omentum as a support for bioengineered tissue therapy for cardiac regeneration in vivo.

Omentum support for cardiac regeneration in ischaemic cardiomyopathy models: a systematic scoping review.

Despite the latest advances in cardiovascular biology and medicine, myocardial infarction (MI) remains one of the major causes of deaths worldwide. While reperfusion of the myocardium is critical to limit the ischemic damage typical of a MI event, it causes detrimental morphological and functional changes known as "reperfusion injury." This complex scenario is poorly represented in currently available models of ischemia/reperfusion injury, leading to a poor translation of findings from the bench to the bedside. However, more recent bioengineered in vitro models of the human heart represent more clinically relevant tools to prevent and treat MI in patients. These include 3D cultures of cardiac cells, the use of patient-derived stem cells, and 3D bioprinting technology. This review aims at highlighting the major features typical of a heart attack while comparing current in vitro, ex vivo, and in vivo models. This information has the potential to further guide in developing novel advanced in vitro cardiac models of ischemia/reperfusion injury. It may pave the way for the generation of advanced pathophysiological cardiac models with the potential to develop personalized therapies.

ArticleTotal : 2	Year
Publication title	2020
Publication title	2021

Article	Year
Glutathionylation mediates angiotensin II-induced eNOS uncoupling, amplifying NADPH oxidase-dependent endothelial dysfunction. Journal of the American Heart Association\| PubMed ID: 24755153	2014
Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) Promotes Angiogenesis and Ischemia-Induced Neovascularization Via NADPH Oxidase 4 (NOX4) and Nitric Oxide-Dependent Mechanisms... Journal of the American Heart Association\| PubMed ID: 26572549	2015
β3 Adrenergic Stimulation Restores Nitric Oxide/Redox Balance and Enhances Endothelial Function in Hyperglycemia. Journal of the American Heart Association\| PubMed ID: 26896479	2016
Cardiac spheroids as promising in vitro models to study the human heart microenvironment. Scientific reports\| PubMed ID: 28765558	2017
Vascularized Cardiac Spheroids as Novel 3D in vitro Models to Study Cardiac Fibrosis. Cells, tissues, organs\| PubMed ID: 28772272	2017
Versatile Fabrication Approach of Conductive Hydrogels via Copolymerization with Vinyl Monomers. ACS applied materials & interfaces\| PubMed ID: 29172417	2017
Current Technologies Based on the Knowledge of the Stem Cells Microenvironments. Advances in experimental medicine and biology\| PubMed ID: 29204837	2017
Stem Cell-Derived Cardiac Spheroids as 3D In Vitro Models of the Human Heart Microenvironment. Methods in molecular biology (Clifton, N.J.)\| PubMed ID: 30159827	2019
Current challenges in three-dimensional bioprinting heart tissues for cardiac surgery. European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery\| PubMed ID: 32391914	2020
Omentum support for cardiac regeneration in ischaemic cardiomyopathy models: a systematic scoping review. European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery\| PubMed ID: 32808023	2020
Considerations for the Bioengineering of Advanced Cardiac In Vitro Models of Myocardial Infarction. Small (Weinheim an der Bergstrasse, Germany)\| PubMed ID: 33464713	2021

Carmine Gentile

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