scholarly journals Wafer-Scale Patterning of Protein Templates for Hydrogel Fabrication

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1386
Author(s):  
Anna A. Kim ◽  
Erica A. Castillo ◽  
Kerry V. Lane ◽  
Gabriela V. Torres ◽  
Orlando Chirikian ◽  
...  

Human-induced pluripotent stem cell-derived cardiomyocytes are a potentially unlimited cell source and promising patient-specific in vitro model of cardiac diseases. Yet, these cells are limited by immaturity and population heterogeneity. Current in vitro studies aiming at better understanding of the mechanical and chemical cues in the microenvironment that drive cellular maturation involve deformable materials and precise manipulation of the microenvironment with, for example, micropatterns. Such microenvironment manipulation most often involves microfabrication protocols which are time-consuming, require cleanroom facilities and photolithography expertise. Here, we present a method to increase the scale of the fabrication pipeline, thereby enabling large-batch generation of shelf-stable microenvironment protein templates on glass chips. This decreases fabrication time and allows for more flexibility in the subsequent steps, for example, in tuning the material properties and the selection of extracellular matrix or cell proteins. Further, the fabrication of deformable hydrogels has been optimized for compatibility with these templates, in addition to the templates being able to be used to acquire protein patterns directly on the glass chips. With our approach, we have successfully controlled the shapes of cardiomyocytes seeded on Matrigel-patterned hydrogels.

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1733 ◽  
Author(s):  
Michele Filippo Buono ◽  
Lisa von Boehmer ◽  
Jaan Strang ◽  
Simon P. Hoerstrup ◽  
Maximilian Y. Emmert ◽  
...  

Genetic cardiomyopathies are characterized by changes in the function and structure of the myocardium. The development of a novel in vitro model could help to better emulate healthy and diseased human heart conditions and may improve the understanding of disease mechanisms. In this study, for the first time, we demonstrated the generation of cardiac organoids using a triculture approach of human induced pluripotent stem-cell-derived cardiomyocytes (hiPS-CMs)—from healthy subjects and cardiomyopathy patients—human cardiac microvascular endothelial cells (HCMECs) and human cardiac fibroblasts (HCFs). We assessed the organoids’ suitability as a 3D cellular model for the representation of phenotypical features of healthy and cardiomyopathic hearts. We observed clear differences in structure and beating behavior between the organoid groups, depending on the type of hiPS-CMs (healthy versus cardiomyopathic) used. Organoids may thus prove a promising tool for the design and testing of patient-specific treatments as well as provide a platform for safer and more efficacious drug development.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Sang-Ging Ong ◽  
Won Hee Lee ◽  
Kazuki Kodo ◽  
Haodi Wu ◽  
Joseph C Wu

Diabetic cardiomyopathy is a common consequence of diabetes and associated with mitochondrial pathology. Using human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) as an in vitro model of diabetes, we sought to understand the role of mitophagy, a process that selectively degrades mitochondria through the autophagy-lysosome pathway as a crucial quality control pathway against diabetic cardiomyopathy. We first showed that iPSC-CMs exposed to a diabetic milieu demonstrated increased hypertrophy, impaired calcium signaling, and higher oxidative stress. Flow cytometry analysis of iPSC-CMs subjected to diabetic conditions revealed two distinct population of cells (normal and hypertrophied), suggesting a heterogeneous response to hyperglycemia. In these cells, hypertrophied iPSC-CMs were found to have reduced mitophagy compared to normal cells when exposed to hyperglycemia. In addition, we showed that mitochondrial fragmentation was also decreased in the hypertrophied iPSC-CMs compared to normal cells upon exposure to hyperglycemia, demonstrating a link between mitochondrial fragmentation and mitophagy. Surprisingly, pretreatment of iPSC-CMs with a non-selective antioxidant, N-(2-mercaptopropionyl)-glycine, not only failed to limit the deleterious effects of hyperglycemia, but actually led to increased hypertrophy and cell death. We found that mitophagy was significantly reduced in iPSC-CMs following antioxidant treatment, suggesting the need of mild oxidative stress as a trigger for mitophagy. Future studies are warranted to further investigate the association between oxidative stress, mitochondrial fragmentation, and mitochondrial fission as targets against diabetic cardiomyopathy.


Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Michelle R Santoso ◽  
Yuko Tada ◽  
Gentaro Ikeda ◽  
Ji-Hye Jung ◽  
Evgeniya Vaskova ◽  
...  

Background: Induced pluripotent stem cells (iPSCs) and their differentiated cardiomyocytes (iCMs) have tremendous potential as patient-specific therapy for myocardial injury (MI). Our previous work showed that the iCMs restore the injured murine myocardium through secretion of paracrine factors, modulating apoptotic pathways to restore the murine peri-infarct region (PIR). Hypothesis: iCM-derived exosomes (iCM-Ex), a major constituent of the iCM secretome, may salvage the injured cardiomyocytes in the PIR. Methods: iCM-Ex were precipitated from iCM supernatant and characterized using various molecular analyses. Immunodeficient mice sustained MIs and received iCMs, iCM-Ex, or PBS control via direct intramyocardial injection into the PIR. Cardiac MRI assessed LV ejection fraction (LVEF) and viability at 2- and 4-week post-injection. iCMs, iCM-Ex, and PIR tissue were isolated for molecular and histological analyses. Results: iCM-Ex measured approximately 142 nm and expressed CD63 and CD9. iCM and iCM-Ex miRNA profiles had significant overlap, indicating that exosomal content was reflective of the parent cell. In vitro iCM apoptosis was increased significantly by hypoxia and exosome biogenesis inhibition while iCM-Ex or rapamycin reduced iCM apoptosis (p<0.05, vs. control). Mice treated with iCMs or iCM-Ex had significantly improved LVEF and LV viability compared to the control (p<0.05). Apoptosis and fibrosis were significantly reduced in iCM- and iCM-Ex treated mice. Autophagy and associated mTOR signaling pathway were significantly enhanced in iCM-Ex treatment group. Conclusions: iCM-Ex demonstrated similar efficacy as the iCMs in improving post-MI cardiac function by regulating autophagy and apoptosis of hypoxia injured cardiomyocytes. This finding represents the potential of cell-free, patient-specific biologic to treat ischemic cardiomyopathy by stimulation of an endogenous repair mechanism.


2020 ◽  
Vol 7 (3) ◽  
pp. 135
Author(s):  
Hiraganahalli Bhaskar Deepak ◽  
Nellikalaya Shreekrishna ◽  
Zaheerbasha Sameermahmood ◽  
Niranjan Naranapur Anand ◽  
Raghotham Hulgi ◽  
...  

2021 ◽  
Vol 22 (15) ◽  
pp. 8132
Author(s):  
Jennifer Zhang ◽  
Oscar Hou-In Chou ◽  
Yiu-Lam Tse ◽  
Kwong-Man Ng ◽  
Hung-Fat Tse

Inherited cardiomyopathies are among the major causes of heart failure and associated with significant mortality and morbidity. Currently, over 70 genes have been linked to the etiology of various forms of cardiomyopathy, some of which are X-linked. Due to the lack of appropriate cell and animal models, it has been difficult to model these X-linked cardiomyopathies. With the advancement of induced pluripotent stem cell (iPSC) technology, the ability to generate iPSC lines from patients with X-linked cardiomyopathy has facilitated in vitro modelling and drug testing for the condition. Nonetheless, due to the mosaicism of the X-chromosome inactivation, disease phenotypes of X-linked cardiomyopathy in heterozygous females are also usually more heterogeneous, with a broad spectrum of presentation. Recent advancements in iPSC procedures have enabled the isolation of cells with different lyonisation to generate isogenic disease and control cell lines. In this review, we will summarise the current strategies and examples of using an iPSC-based model to study different types of X-linked cardiomyopathy. The potential application of isogenic iPSC lines derived from a female patient with heterozygous Danon disease and drug screening will be demonstrated by our preliminary data. The limitations of an iPSC-derived cardiomyocyte-based platform will also be addressed.


JCI Insight ◽  
2021 ◽  
Author(s):  
Justin Davis ◽  
Ahmad Chouman ◽  
Jeffery Creech ◽  
Andre Monteiro da Rocha ◽  
Daniela Ponce-Balbuena ◽  
...  

2020 ◽  
Vol 21 (4) ◽  
pp. 1438 ◽  
Author(s):  
John P. Gleeson ◽  
Hannah Q. Estrada ◽  
Michifumi Yamashita ◽  
Clive N. Svendsen ◽  
Stephan R. Targan ◽  
...  

In inflammatory bowel disease (IBD), the intestinal epithelium is characterized by increased permeability both in active disease and remission states. The genetic underpinnings of this increased intestinal permeability are largely unstudied, in part due to a lack of appropriate modelling systems. Our aim is to develop an in vitro model of intestinal permeability using induced pluripotent stem cell (iPSC)-derived human intestinal organoids (HIOs) and human colonic organoids (HCOs) to study barrier dysfunction. iPSCs were generated from healthy controls, adult onset IBD, and very early onset IBD (VEO-IBD) patients and differentiated into HIOs and HCOs. EpCAM+ selected cells were seeded onto Transwell inserts and barrier integrity studies were carried out in the presence or absence of pro-inflammatory cytokines TNFα and IFNγ. Quantitative real-time PCR (qRT-PCR), transmission electron microscopy (TEM), and immunofluorescence were used to determine altered tight and adherens junction protein expression or localization. Differentiation to HCO indicated an increased gene expression of CDX2, CD147, and CA2, and increased basal transepithelial electrical resistance compared to HIO. Permeability studies were carried out in HIO- and HCO-derived epithelium, and permeability of FD4 was significantly increased when exposed to TNFα and IFNγ. TEM and immunofluorescence imaging indicated a mislocalization of E-cadherin and ZO-1 in TNFα and IFNγ challenged organoids with a corresponding decrease in mRNA expression. Comparisons between HIO- and HCO-epithelium show a difference in gene expression, electrophysiology, and morphology: both are responsive to TNFα and IFNγ stimulation resulting in enhanced permeability, and changes in tight and adherens junction architecture. This data indicate that iPSC-derived HIOs and HCOs constitute an appropriate physiologically responsive model to study barrier dysfunction and the role of the epithelium in IBD and VEO-IBD.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Marcela K Preininger ◽  
Rajneesh Jha ◽  
Qingling Wu ◽  
Monalisa Singh ◽  
Joshua T Maxwell ◽  
...  

Introduction: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by diastolic store overload-induced Ca2+ waves during β-adrenergic receptor (β-AR) stimulation. Mysteriously, β-blockers are ineffective at abolishing stress-induced ventricular arrhythmias in ~25% of patients. Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) generated from these CPVT patients offer an attractive system for investigating the phenomenon, but it remains unknown whether iPSC-CMs can recapitulate clinically observed patient-specific drug responses. Hypothesis: This study assessed the hypothesis that patient-specific refractoriness to β-blocker therapy can be observed in vitro using CPVT iPSC-CMs. Methods: We generated iPSC-CMs from a control individual and a CPVT patient insensitive to the widely prescribed β-blocker nadolol, but responsive to flecainide, and compared the efficacy of the two drugs in vitro in diminishing diastolic Ca2+ waves and restoring Ca2+ spark parameters during β-AR stimulation. Results: In CPVT hiPSC-CMs (n = 34), β-AR agonism elicited intense diastolic Ca2+ waves and potentiated unduly frequent, large, and prolonged Ca2+ sparks compared to control iPSC-CMs (n = 12). Pursuant to the patient’s in vivo responses, nadolol-treated CPVT iPSC-CMs (n = 27) demonstrated inadequate improvement of Ca2+ handling defects during β-AR stimulation relative to flecainide-treated CPVT iPSC-CMs (n = 25). Nadolol showed no significant effect on the frequency of diastolic Ca2+ waves, but reduced mean amplitude by 50% (p < 0.0001). In contrast, flecainide reduced both frequency and amplitude by 83% (p < 0.001) and 72% (p < 0.0001), respectively. During nadolol treatment, Ca2+ spark frequency, width, and duration remained significantly altered, while flecainide restored all Ca2+ spark parameters to baseline levels. Conclusions: Clinically observed recalcitrance to β-blocker therapy in individuals with CPVT can be modeled in vitro using patient-derived iPSC-CMs. Furthermore, the efficacy of other drugs such as flecainide can be comparatively evaluated, supporting the use of patient-specific iPSC-CMs as a clinically-relevant implement of precision medicine.


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