The Benefits of Stem Cell Biology and Tissue Engineering in Low-Earth Orbit.

Over the past 15 years, there has been a significant shift in biomedical research toward a major focus on stem cell research. Although stem cells and their derivatives exhibit potential in modeling and mitigating human diseases, the ongoing objective is to enhance their utilization and translational potential. Stem cells are increasingly employed in both academic and commercial settings for a variety of in vitro and in vivo applications in regenerative medicine. Notably, accessibility to stem cell research in low-Earth orbit (LEO) has expanded, driven by the unique properties of space, such as microgravity, which cannot exactly be replicated on Earth. As private enterprises continue to grow and launch low-orbit payloads alongside government-funded spaceflight, space has evolved into a more viable destination for scientific exploration. This review underscores the potential benefits of microgravity on fundamental stem cell properties, highlighting the adaptability of cells to their environment and emphasizing physical stimuli as a key factor influencing cultured cells. Previous studies suggest that stimuli such as magnetic fields, shear stress, or gravity impact not only cell kinetics, including differentiation and proliferation, but also therapeutic effects such as cells with improved immunosuppressive capabilities or the ability to identify novel targets to refine disease treatments. With the rapid progress and sustained advocacy for space research, we propose that the advantageous properties of LEO create novel opportunities in biomanufacturing for regenerative medicine, spanning disease modeling, the development of stem cell-derived products, and biofabrication.

Multi-lineage heart-chip models drug cardiotoxicity and enhances maturation of human stem cell-derived cardiovascular cells.

Cardiovascular toxicity causes adverse drug reactions and may lead to drug removal from the pharmaceutical market. Cancer therapies can induce life-threatening cardiovascular side effects such as arrhythmias, muscle cell death, or vascular dysfunction. New technologies have enabled cardiotoxic compounds to be identified earlier in drug development. Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CMs) and vascular endothelial cells (ECs) can screen for drug-induced alterations in cardiovascular cell function and survival. However, most existing hiPSC models for cardiovascular drug toxicity utilize two-dimensional, immature cells grown in static culture. Improved in vitro models to mechanistically interrogate cardiotoxicity would utilize more adult-like, mature hiPSC-derived cells in an integrated system whereby toxic drugs and protective agents can flow between hiPSC-ECs that represent systemic vasculature and hiPSC-CMs that represent heart muscle (myocardium). Such models would be useful for testing the multi-lineage cardiotoxicities of chemotherapeutic drugs such as VEGFR2/PDGFR-inhibiting tyrosine kinase inhibitors (VPTKIs). Here, we develop a multi-lineage, fully-integrated, cardiovascular organ-chip that can enhance hiPSC-EC and hiPSC-CM functional and genetic maturity, model endothelial barrier permeability, and demonstrate long-term functional stability. This microfluidic organ-chip harbors hiPSC-CMs and hiPSC-ECs on separate channels that can be subjected to active fluid flow and rhythmic biomechanical stretch. We demonstrate the utility of this cardiovascular organ-chip as a predictive platform for evaluating multi-lineage VPTKI toxicity. This study may lead to the development of new modalities for the evaluation and prevention of cancer therapy-induced cardiotoxicity.

Protein-encapsulated doxorubicin reduces cardiotoxicity in hiPSC-cardiomyocytes and cardiac spheroids while maintaining anticancer efficacy.

The chemotherapeutic doxorubicin (DOX) detrimentally impacts the heart during cancer treatment. This necessitates development of non-cardiotoxic delivery systems that retain DOX anticancer efficacy. We used human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), endothelial cells (hiPSC-ECs), cardiac fibroblasts (hiPSC-CFs), multi-lineage cardiac spheroids (hiPSC-CSs), patient-specific hiPSCs, and multiple human cancer cell lines to compare the anticancer efficacy and reduced cardiotoxicity of single protein encapsulated DOX (SPEDOX-6), to standard unformulated (UF) DOX. Cell viability assays and immunostaining in human cancer cells, hiPSC-ECs, and hiPSC-CFs revealed robust uptake of SPEDOX-6 and efficacy in killing these proliferative cell types. In contrast, hiPSC-CMs and hiPSC-CSs exhibited substantially lower cytotoxicity during SPEDOX-6 treatment compared with UF DOX. SPEDOX-6-treated hiPSC-CMs and hiPSC-CSs maintained their functionality, as indicated by sarcomere contractility assessment, calcium imaging, multielectrode arrays, and RNA sequencing. This study demonstrates the potential of SPEDOX-6 to alleviate cardiotoxic side effects associated with UF DOX, while maintaining its anticancer potency.

Microfluidic Organ-Chips and Stem Cell Models in the Fight Against COVID-19.

SARS-CoV-2, the virus underlying COVID-19, has now been recognized to cause multiorgan disease with a systemic effect on the host. To effectively combat SARS-CoV-2 and the subsequent development of COVID-19, it is critical to detect, monitor, and model viral pathogenesis. In this review, we discuss recent advancements in microfluidics, organ-on-a-chip, and human stem cell-derived models to study SARS-CoV-2 infection in the physiological organ microenvironment, together with their limitations. Microfluidic-based detection methods have greatly enhanced the rapidity, accessibility, and sensitivity of viral detection from patient samples. Engineered organ-on-a-chip models that recapitulate in vivo physiology have been developed for many organ systems to study viral pathology. Human stem cell-derived models have been utilized not only to model viral tropism and pathogenesis in a physiologically relevant context but also to screen for effective therapeutic compounds. The combination of all these platforms, along with future advancements, may aid to identify potential targets and develop novel strategies to counteract COVID-19 pathogenesis.

Chemically Defined Production of Tri-Lineage Human iPSC-Derived Cardiac Spheroids.

Cardiac spheroids derived from human induced pluripotent stem cells (hiPSC-cardiac spheroids) represent a powerful three-dimensional (3D) model for examining cardiac physiology and for drug toxicity screening. Recent advances with self-organizing, multicellular cardiac organoids highlight the capability of directed stem cell differentiation approaches to recapitulate the composition of the human heart in vitro. Using hiPSC-derived cardiomyocytes (hiPSC-CMs), hiPSC-derived endothelial cells (hiPSC-ECs), and hiPSC-derived cardiac fibroblasts (hiPSC-CFs) is advantageous for enabling tri-cellular crosstalk within a multilineage system and for generating patient-specific models. Chemically defined medium containing factors needed to simultaneously maintain hiPSC-CMs, hiPSC-ECs, and hiPSC-CFs is used to produce the spheroid system. In this article, we present protocols to illustrate the methods for conducting small-molecule-mediated differentiations of hiPSCs into cardiomyocytes, endothelial cells, and cardiac fibroblasts, as well as to assemble the fully integrated cardiac spheroids. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Maintenance and expansion of hiPSCs Basic Protocol 2: Differentiation of hiPSCs into cardiomyocytes Basic Protocol 3: Differentiation of hiPSCs into vascular endothelial cells Basic Protocol 4: Differentiation of hiPSCs into cardiac fibroblasts Basic Protocol 5: Production of hiPSC-derived cardiac spheroids.

Modeling Cardiac SARS-CoV-2 Infection with Human Pluripotent Stem Cells.

Although SARS-CoV-2, the causative virus of the global COVID-19 pandemic, primarily affects the respiratory tract, it is now recognized to have broad multi-organ tropism and systemic effects. Early reports indicated that SARS-CoV-2 infection could lead to cardiac damage, suggesting the virus may directly impact the heart. Cardiac cell types derived from human pluripotent stem cells (hPSCs) enable mechanistic interrogation of SARS-CoV-2 infection in human cardiac tissue. PURPOSE OF REVIEW: To review the studies published since the emergence of the COVID-19 pandemic which utilize hPSCs and their cardiovascular derivative cell types to interrogate the tropism and effects of SARS-CoV-2 infection in the heart, as well as explore potential therapies. RECENT FINDINGS: Recent studies reveal that SARS-CoV-2 is capable of infecting and replicating within hPSC-derived cardiomyocytes and sinoatrial nodal cells, but not as extensively in their non-parenchymal counterparts. Additionally, they show striking viral effects on cardiomyocyte structure, transcriptional activity, and survival, along with potential mechanisms and therapeutic targets. Cardiac models derived from hPSCs are a viable platform to study the impact of SARS-CoV-2 on cardiac tissue and may lead to novel mechanistic insight as well as therapeutic interventions.