Research and therapy with induced pluripotent stem cells (iPSCs): social, legal, and ethical considerations

Current biological, chemical and physical gene delivery approaches for producing induced pluripotent stem cells (iPSCs)

The discovery of induced pluripotent stem cells (iPSCs) has revolutionized the research platform for disease modeling, drug discovery, cell therapy and regenerative medicine. Due to the importance of iPSCs over the past decade, various studies have focused on finding a safe and efficient gene delivery system to introduce reprogramming factors (RFs) into somatic cells, particularly for clinical applications. However, generated iPSCs from any source must undergo genomic, epigenomic, and functional characterizations to ensure they are free of somatic memories and safe for clinical application. In this review, almost all the employed cargos for delivering RFs into somatic cells were investigated, focusing on biological, chemical, and physical approaches to promote reprogramming efficiency and reduce exogenous factors. Moreover, the advantages and disadvantages of each approach were highlighted and cutting-edge technologies in iPSCs technology were also discussed. This review aims to provide a comprehensive overview discussing how to improve the efficiency and quality of iPSCs production.

Elimination of tumorigenic pluripotent stem cells from their differentiated cell therapy products: An important step toward ensuring safe cell therapy

Human pluripotent stem cells (hPSCs) are considered a promising tool for regenerative medicine due to their unique self-renewal and multi-lineage differentiation capabilities. Although over 100 clinical trials have employed hPSC-derived products to treat life-threatening diseases, the tumorigenic risk posed by residual undifferentiated hPSCs remains a formidable obstacle to their clinical implementation. In this review, we summarize current strategies to eliminate tumorigenic hPSCs, most of which target hPSC-specific markers, and critically evaluate the advantages and limitations of each approach. Finally, we discuss various methods that can be used to evaluate the efficiency of pluripotent stem cell (PSC) elimination.

Insights on the Characteristics and Therapeutic Potential of Mesenchymal Stem Cell-derived Exosomes for Mitigation of Alzheimer's Disease's Pathogenicity: A Systematic Review

Alzheimer's disease (AD) remains a progressive neurodegenerative disease with no cure. Treatment of AD relies on administering drugs that only subside the symptoms. In recent studies, mesenchymal stem cell (MSC)-exosomes have been marked to possess therapeutic potential for treating AD. This study aims to systematically review and analyse findings that focus on the isolation, characterisation, and sources of MSC-derived exosomes used to unravel the therapeutic potential of these exosomes targeting AD using in vitro and in vivo models. It is hypothesised that MSC-exosomes exhibit high therapeutic potential for AD treatment by exerting various modes of action. PubMed, Scopus, and Medline were used to find relevant published works from January 2016 until December 2020, using assigned keywords including "Alzheimer's disease", "secretome", and "exosomes". Only research articles meeting the predefined inclusion/exclusion criteria were selected and analysed. The risk of bias was assessed using the Office of Health Assessment and Translation tool (OHAT). A total of 17 eligible in vivo and in vitro studies were included in this review. Bone marrow-derived stem cells (BMSCs) were the most used source for exosome isolation, even though studies on exosomes from adipose-derived stem cells (ADSCs) and human umbilical cord stem cells (HUCSCs) provide more information on the characteristics. When the risk of bias was assessed, the studies presented various levels of biases. Notably, the in vitro and in vivo studies revealed neuroprotective properties of MSC-exosomes through different modes of action to alleviate AD pathology. Our review discovered that most MSC exosomes could degrade Aβ plaques, enhance neurogenesis, extenuate neuroinflammatory response through microglial activation, regulate apoptosis and reduce oxidative stress. Delivery of exosomal micro-RNAs was also found to reduce neuroinflammation. Findings from this review provided convincing systematic evidence highlighting the therapeutic properties of MSC-derived exosomes as a prospective source for cell-free (acellular) therapy in treating AD.

Next-generation immunotherapeutic approaches for blood cancers: Exploring the efficacy of CAR-T and cancer vaccines

Recent advancements in immunotherapy, particularly Chimeric antigen receptor (CAR)-T cell therapy and cancer vaccines, have significantly transformed the treatment landscape for leukemia. CAR-T cell therapy, initially promising in hematologic cancers, faces notable obstacles in solid tumors due to the complex and immunosuppressive tumor microenvironment. Challenges include the heterogeneous immune profiles of tumors, variability in antigen expression, difficulties in therapeutic delivery, T cell exhaustion, and reduced cytotoxic activity at the tumor site. Additionally, the physical barriers within tumors and the immunological camouflage used by cancer cells further complicate treatment efficacy. To overcome these hurdles, ongoing research explores the synergistic potential of combining CAR-T cell therapy with cancer vaccines and other therapeutic strategies such as checkpoint inhibitors and cytokine therapy. This review describes the various immunotherapeutic approaches targeting leukemia, emphasizing the roles and interplay of cancer vaccines and CAR-T cell therapy. In addition, by discussing how these therapies individually and collectively contribute to tumor regression, this article aims to highlight innovative treatment paradigms that could enhance clinical outcomes for leukemia patients. This integrative approach promises to pave the way for more effective and durable treatment strategies in the oncology field. These combined immunotherapeutic strategies hold great promise for achieving more complete and lasting remissions in leukemia patients. Future research should prioritize optimizing treatment sequencing, personalizing therapeutic combinations based on individual patient and tumor characteristics, and developing novel strategies to enhance T cell persistence and function within the tumor microenvironment. Ultimately, these efforts will advance the development of more effective and less toxic immunotherapeutic interventions, offering new hope for patients battling this challenging disease.

Engineering the Future of Regenerative Medicines in Gut Health with Stem Cell-Derived Intestinal Organoids

The advent of intestinal organoids, three-dimensional structures derived from stem cells, has significantly advanced the field of biology by providing robust in vitro models that closely mimic the architecture and functionality of the human intestine. These organoids, generated from induced pluripotent stem cells (iPSCs), embryonic stem cells (ESCs), or adult stem cells, possess remarkable capabilities for self-renewal, differentiation into diverse intestinal cell types, and functional recapitulation of physiological processes, including nutrient absorption, epithelial barrier integrity, and host-microbe interactions. The utility of intestinal organoids has been extensively demonstrated in disease modeling, drug screening, and personalized medicine. Notable examples include iPSC-derived organoids, which have been effectively employed to model enteric infections, and ESC-derived organoids, which have provided critical insights into fetal intestinal development. Patient-derived organoids have emerged as powerful tools for investigating personalized therapeutics and regenerative interventions for conditions such as inflammatory bowel disease (IBD), cystic fibrosis, and colorectal cancer. Preclinical studies involving transplantation of human intestinal organoids into murine models have shown promising outcomes, including functional integration, epithelial restoration, and immune system interactions. Despite these advancements, several challenges persist, particularly in achieving reproducibility, scalability, and maturation of organoids, which hinder their widespread clinical translation. Addressing these limitations requires the establishment of standardized protocols for organoid generation, culture, storage, and analysis to ensure reproducibility and comparability of findings across studies. Nevertheless, intestinal organoids hold immense promise for transforming our understanding of gastrointestinal pathophysiology, enhancing drug development pipelines, and advancing personalized medicine. By bridging the gap between preclinical research and clinical applications, these organoids represent a paradigm shift in the exploration of novel therapeutic strategies and the investigation of gut-associated diseases.

Effects of SGLT2 inhibitors on ion channels in heart failure: focus on the endothelium

Heart failure (HF) is a life-threatening cardiovascular disease associated with high mortality, diminished quality of life, and a significant economic burden on both patients and society. The pathogenesis of HF is closely related to the endothelium, where endothelial ion channels play an important role in regulating intracellular Ca2+ signals. These ion channels are essential to maintain vascular function, including endothelium-dependent vascular tone, inflammation response, and oxidative stress. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have shown promising cardiovascular benefits in HF patients, reducing mortality risk and hospitalization in several large clinical trials. Clinical and preclinical studies indicate that the cardioprotective effects of SGLT2i in HF are mediated by endothelial nitric oxide (NO) pathways, as well as by reducing inflammation and reactive oxygen species in cardiac endothelial cells. Additionally, SGLT2i may confer endothelial protection by lowering intracellular Ca2+ level through the inhibition of sodium-hydrogen exchanger 1 (NHE1) and sodium-calcium exchanger (NCX) in endothelial cells. In this review, we discuss present knowledge regarding the expression and role of Ca2+-related ion channels in endothelial cells in HF, focusing on the effects of SGLT2i on endothelial NHE1, NCX as well as on vascular tone.

Advances in cell therapy for orthopedic diseases: bridging immune modulation and regeneration

Orthopedic diseases pose significant challenges to public health due to their high prevalence, debilitating effects, and limited treatment options. Additionally, orthopedic tumors, such as osteosarcoma, chondrosarcoma, and Ewing sarcoma, further complicate the treatment landscape. Current therapies, including pharmacological treatments and joint replacement, address symptoms but fail to promote true tissue regeneration. Cell-based therapies, which have shown successful clinical results in cancers and other diseases, have emerged as a promising solution to repair damaged tissues and restore function in orthopedic diseases and tumors. This review discusses the advances and potential application of cell therapy for orthopedic diseases, with a particular focus on osteoarthritis, bone fractures, cartilage degeneration, and the treatment of orthopedic tumors. We explore the potential of mesenchymal stromal cells (MSCs), chondrocyte transplantation, engineered immune cells and induced pluripotent stem cells to enhance tissue regeneration by modulating the immune response and addressing inflammation. Ultimately, the integration of cutting-edge cell therapy, immune modulation, and molecular targeting strategies could revolutionize the treatment of orthopedic diseases and tumors, providing hope for patients seeking long-term solutions to debilitating conditions.

The Potential and Challenges of Human Pluripotent Stem Cells in the Treatment of Diabetic Nephropathy

Diabetic nephropathy (DN) is a prevalent complication of diabetes, with current treatment options offering limited effectiveness, particularly in advanced stages. Human pluripotent stem cells (hPSCs), particularly induced PSCs (iPSCs), show promising potential in the treatment of DN due to their pluripotency, capacity for differentiation into kidney-specific cells, and suitability for personalized therapies. iPSC-based personalized approaches can effectively mitigate immune rejection, a common challenge with allogeneic transplants, thus enhancing therapeutic outcomes. Clustered regularly interspaced short palindromic repeats (CRISPR) gene editing further enhances the potential of hPSCs by enabling the precise correction of disease-associated genetic defects, increasing both the safety and efficacy of therapeutic cells. In addition to direct treatment, hPSCs have proven valuable in disease modeling and drug screening, particularly for identifying and validating disease-specific targets. Kidney organoids derived from hPSCs replicate key features of DN pathology, making them useful platforms for validating therapeutic targets and assessing drug efficacy. Comparatively, both hPSCs and mesenchymal SCs (MSCs) have shown promise in improving renal function in preclinical models, with hPSCs offering broader differentiation capacity. Integration with tissue engineering technologies, such as three-dimensional bioprinting and bioengineered scaffolds, expands the regenerative potential of hPSCs by supporting the formation of functional renal structures and enhancing in vivo integration and regenerative capacity. Despite current challenges, such as tumorigenicity, genomic instability, and limited direct research, advances in gene editing, differentiation protocols, and tissue engineering promise to address these barriers. Continued optimization of these approaches will likely lead to successful clinical applications of hPSCs, potentially revolutionizing treatment options for DN.

Current Status and Progress in Stem Cell Therapy for Intracerebral Hemorrhage

Intracerebral hemorrhage is a highly prevalent and prognostically poor disease, imposing immeasurable harm on human life and health. However, the treatment options for intracerebral hemorrhage are severely limited, particularly in terms of improving the microenvironment of the lesion, promoting neuronal cell survival, and enhancing neural function. This review comprehensively discussed the application of stem cell therapy for intracerebral hemorrhage, providing a systematic summary of its developmental history, types of transplants, transplantation routes, and transplantation timing. Moreover, this review presented the latest research progress in enhancing the efficacy of stem cell transplantation, including pretransplantation preconditioning, genetic modification, combined therapy, and other diverse strategies. Furthermore, this review pioneeringly elaborated on the barriers to clinical translation for stem cell therapy. These discussions were of significant importance for promoting stem cell therapy for intracerebral hemorrhage, facilitating its clinical translation, and improving patient prognosis.

The mutual impacts of stem cells and sleep: opportunities for improved stem cell therapy

Sleep is an indispensable physiological function regulated by circadian rhythms, which influence the biological pathways and overall health of the body. Sleep is crucial for the maintenance and restoration of bodily systems, and disturbances can lead to various sleep disorders, which can impair both mental and physical health. Treatment options for these disorders encompass lifestyle modifications, psychotherapy, medications, and therapies such as light therapy and surgery. Not only sleep deprivation has a significant impact on essential organs, but it also influences various types of stem cells in the body. In this review, we explore the connection between sleep and various types of stem cells, highlighting how circadian rhythms regulate stem cell activities that are vital for tissue regeneration and homeostasis. Disruptions in sleep can hinder stem cell self-renewal, homing, proliferation, function, and differentiation, thereby affecting tissue regeneration and overall health. We also discuss how transplantation of stem cells and their products may help improve sleep disorders, how sleep quality affects stem cell behavior, and the implications for stem cell therapies. Notably, while certain stem cell transplantations can disrupt sleep, enhancing sleep quality may improve the efficacy of these therapies. Finally, stem cells can be utilized to model sleep disorders, offering valuable insights into their underlying mechanisms.

Induced Mesenchymal Stem Cells: An Emerging Source for Regenerative Medicine Applications

Regenerative medicine is gaining interest in the medical field due to the limitations of conventional treatments, which often fail to address the underlying cause of disease. In recent years, stem cell-based therapies have evolved as a promising alternative approach to treat those diseases that cannot be cured using conventional medicine. Adult stem cells, particularly the mesenchymal stem cells (MSCs), have attracted a lot of attention due to their ability to regenerate and repair human tissues and organs. MSCs isolated from adult tissues are well characterized and are currently the most common type of cells for use in regenerative medicine. However, their low number in adult donor tissues, donor-age and cell-source related heterogeneity, limited proliferative and differentiation potential, and early senescence in in vitro cultures, negatively affect MSC regenerative potential. These factors restrict MSC use for research as well as for clinical applications. To overcome these problems, MSCs with superior regenerative potential are required. Induced MSCs (iMSCs) are obtained from induced pluripotent stem cells (iPSCs). These cells are patient-specific, readily available, and have relatively superior regenerative potential and, therefore, can overcome the problems associated with the use of primary MSCs. In this review, the authors aim to discuss the characteristics, regenerative potential, and limitations of MSCs for regenerative medicine applications. The main methods to generate iMSCs from iPSCs have been discussed in detail. In addition, the proposed criteria for their molecular characterization, applications of iMSCs for disease modeling and drug discovery, as well as potential use in regenerative medicine have been explored in detail.

Trends and considerations in annulus fibrosus in vitro model design

Annulus Fibrosus (AF) tissue integrity maintains intervertebral disc (IVD) structure, essential to spine mobility and shock absorption. However, this tissue, which confines nucleus pulposus (NP), has been poorly investigated, partially due to the lack of appropriate study models. This review provides a comprehensive analysis of AF in vitro models. By critically assessing the current AF in vitro models, this works thoroughly identifies key gaps in replicating the tissue's complex microenvironment. Finally, we outline the essential criteria for developing more accurate and reliable AF models, emphasizing the importance of biomaterial composition, architecture, and microenvironmental cues. By advancing in vitro models, we aim to deepen the understanding of AF failure mechanisms and support the development of novel therapeutic strategies for IVD herniation. Insights gained from this review may also have broader applications in regenerative medicine, particularly in the study and treatment of other connective tissue disorders. STATEMENT OF SIGNIFICANCE: This review evaluates the current in vitro models of the annulus fibrosus (AF), a key component of the intervertebral disc (IVD). By identifying gaps in these models, particularly in replicating tissue's complex microenvironment, we propose essential criteria for the development of more accurate AF models, to better understand the pathomechanisms and potentially aid the development of therapeutic approaches for spinal disorders. The findings also extend to broader studies of musculoskeletal tissue disorders in the context of regenerative medicine, appealing to a diverse biomedical research readership.

Endocannabinoid system upregulates the enrichment and differentiation of human iPSC- derived spermatogonial stem cells via CB2R agonism

BACKGROUND

Male factor infertility (MFI) is responsible for 50% of infertility cases and in 15% of the cases sperm is absent due to germ cell aplasia. Human induced pluripotent stem cell (hiPSC)-derived spermatogonial stem cells (hSSCs) could serve as an autologous germ cell source for MFI in patients with an insufficient sperm yield for assisted reproductive technology (ART). The endocannabinoid system (ECS) has been implicated to play a role in mouse embryonic stem cells (mESCs) and the human testicular environment. However, the contribution of the ECS in hiPSCs and hiPSC-derived hSSCs is currently unknown. Here, we aimed to assess whether hiPSCs and hiPSC-derived hSSCs are regulated by components of the ECS and whether manipulation of the ECS could increase the yield of hiPSC-derived SSCs and serve as an autologous cell-based source for treatment of MFI.

METHODS

We reprogrammed human dermal fibroblasts (hDFs) to hiPSCs, induced differentiation of hSSC from hiPSCs and evaluated the presence of ECS ligands (AEA, 2-AG) by LC/MS, receptors (CB1R, CB2R, TRPV1, GPR55) by qPCR, flow cytometry and immunofluorescent labeling. We then examined the efficacy of endogenous and synthetic selective ligands (ACPA, CB65, CSP, ML184) on proliferation of hiPSCs using real-time cell analysis (RTCA) and assessed the effects of on CB2R agonism on hiPSC pluripotency and differentiation to hSSCs.

RESULTS

hiPSCs from hDFs expressed the pluripotency markers OCT4, SOX2, NANOG, SSEA4 and TRA-1-60; and could be differentiated into ID4+, PLZF + hSSCs. hiPSCs and hiPSC-derived hSSCs secreted AEA and 2-AG at 10- 10 - 10- 9 M levels. Broad expression of all ECS receptors was observed in both hiPSCs and hiPSC-derived hSSCs, with a higher CB2R expression in hSSCs in comparison to hiPSCs. CB2R agonist CB65 promoted proliferation and differentiation of hiPSCs to hiPSC-hSSCs in comparison to AEA, 2-AG, ACPA, CSP and ML184. The EC50 of CB65 was determined to be 2.092 × 10- 8 M for support of pluripotency and preservation of stemness on hiPSCs from 78 h. CB65 stimulation at EC50 also increased the yield of ID4 + hSSCs, PLZF + SSPCs and SCP3 + spermatocytes from day 10 to 12.

CONCLUSIONS

We demonstrated here for the first time that stimulation of CB2R results in an increased yield of hiPSCs and hiPSC-derived hSSCs. CB65 is a potent CB2R agonist that can be used to increase the yield of hiPSC-derived hSSCs offering an alternative source of autologous male germ cells for patients with MFI. Increasing the male germ/stem cell pool by CB65 supplementation could be part of the ART-associated protocols in MFI patients with complete germ cell aplasia.

Synergistic potential of stem cells and microfluidics in regenerative medicine

Regenerative medicine has immense potential to revolutionize healthcare by using regenerative capabilities of stem cells. Microfluidics, a cutting-edge technology, offers precise control over cellular microenvironments. The integration of these two fields provides a deep understanding of stem cell behavior and enables the development of advanced therapeutic strategies. This critical review explores the use of microfluidic systems to culture and differentiate stem cells with precision. We examined the use of microfluidic platforms for controlled nutrient supply, mechanical stimuli, and real-time monitoring, providing an unprecedented level of detail in studying cellular responses. The convergence of stem cells and microfluidics holds immense promise for tissue repair, regeneration, and personalized medicine. It offers a unique opportunity to revolutionize the approach to regenerative medicine, facilitating the development of advanced therapeutic strategies and enhancing healthcare outcomes.

Development of iPSC-derived FIX-secreting hepatocyte sheet as a novel treatment tool for hemophilia B treatment

BACKGROUND

Hemophilia B is an inherited disorder caused by a mutation in the FIX gene, which results in insufficient blood clotting factor IX (FIX) production from hepatocytes. Currently, there are no treatments for hemophilia B patients. The patients should be continuously administrated with clotting factor concentrates 2-3 times a month to prevent bleeding. Therefore, this study aimed to develop an engineered FIX-secreting hepatocyte sheet that can release FIX for an extended period. Within this study, the engineered FIX-secreting hepatocyte sheet was developed by integrating two core technologies, including a gene editing platform to generate FIX-secreting cells and cell sheet technology to improve cell delivery efficacy.

METHODS

The human FIX gene was inserted into the APOC3 site of iPSCs by CRISPR/Cas9, which secretes the target protein after differentiation into hepatocytes. FIX-secreting hepatocyte sheets were obtained by temperature-responsive polymer grafted cell culture dishes (TRCD). Immunohistochemical and functional tests were performed for hepatocyte-like cells differentiated from FIX KI-iPSCs and wild-type iPSCs (WT-iPSCs). After validating the functional activity and secretion of FIX protein, the engineered hepatocyte-like cell sheets were transplanted to NOD/SCID mice for the in vivo experiments.

RESULTS

The insertion of the human FIX gene into the APOC3 site demonstrated a significant increase in FIX secretion in hepatocyte-like cells differentiated from FIX KI-iPSCs compared with those obtained from WT-iPSCs. Among the iPSCs to hepatocyte differentiation stages, the hepatic endoderm stage was most suitable for seeding the cells on TRCD and generating cell sheets by temperature changes from 37oC to room temperature when the hepatocyte-like cells have reached maturity. The engineered FIX-secreting cell sheets showed intensive expression of the FIX proteins without losing hepatocyte morphology for 20 days. Furthermore, an in vivo study showed that engineered FIX-secreting cell sheets retained their FIX secretion functions for two weeks, whereas single-cell injected traditionally were barely detected in the experimental animals.

CONCLUSIONS

The engineered FIX-secreting cell sheets fabricated from functionally improved iPSCs with practical cell delivery tools could be a promising tool for clinically treating Hemophilia B.

Molecular Research on Diabetes

This Special Issue of the International Journal of Molecular Sciences collects the latest research on different biological processes and molecular mechanisms that cause diabetes [...].

Prospects of induced pluripotent stem cells in treating advancing Alzheimer's disease: A review

The World Health Organization has identified Alzheimer's disease (AD), the leading cause of dementia globally, as a public health priority. However, the complex multifactorial pathology of AD means that its etiology remains incompletely understood. Despite being recognized a century ago, incomplete knowledge has hindered the development of effective treatments for AD. Recent scientific advancements, particularly in induced pluripotent stem cell (iPSC) technology, show great promise in elucidating the fundamental mechanisms of AD. iPSCs play a dual role in regenerating damaged cells for therapeutic purposes and creating disease models to understand AD pathology and aid in drug screening. Nevertheless, as an emerging field, iPSC technology requires further technological advancement to develop effective AD treatments in the future. Thus, this review summarizes recent advances in stem cell therapies, specifically iPSCs, aimed at understanding AD pathology and developing treatments.

Stem Cell Therapy for Diseases of Livestock Animals: An In-Depth Review

Stem cells are unique, undifferentiated cells that have the ability to both replicate themselves and develop into specialized cell types. This dual capability makes them valuable in the development of regenerative medicine. Current development in stem cell research has widened their application in cell therapy, drug discovery, reproductive cloning in animals, and cell models for various diseases. Although there are substantial studies revealing the treatment of human degenerative diseases using stem cells, this is yet to be explored in livestock animals. Many diseases in livestock species such as mastitis, laminitis, neuromuscular disorders, autoimmune diseases, and some debilitating diseases are not covered completely by the existing drugs and treatment can be improved by using different types of stem cells like embryonic stem cells, adult stem cells, and induced pluripotent stem cells. This review mainly focuses on the use of stem cells for disease treatment in livestock animals. In addition to the diseases mentioned, the potential of stem cells can be helpful in wound healing, skin disease therapy, and treatment of some genetic disorders. This article explores the potential of stem cells from various sources in the therapy of livestock diseases and also their role in the conservation of endangered species as well as disease model preparation. Moreover, the future perspectives and challenges associated with the application of stem cells in livestock are discussed. Overall, the transformative impact of stem cell research on the livestock sector is comprehensively studied which will help researchers to design future research work on stem cells related to livestock diseases.

Mapping the blueprint of artificial blood vessels research: a bibliometric analysis

BACKGROUND

Vascular diseases represent a significant cause of disability and death worldwide. The demand for artificial blood vessels is increasing due to the scarce supply of healthy autologous vessels. Nevertheless, the literature in this area remains sparse and inconclusive.

METHODS

Bibliometrics is the study of quantitative analysis of publications and their patterns. This study conducts a bibliometric analysis of publications on artificial blood vessels in the 21st century, examining performance distribution, research trajectories, the evolution of research hotspots, and the exploration of the knowledge base. This approach provides comprehensive insights into the knowledge structure of the field.

RESULTS

The search retrieved 2060 articles, showing a consistent rise in the publication volume and average annual citation frequency related to artificial blood vessels research. The United States is at the forefront of high-quality publications and international collaborations. Among academic institutions, Yale University is a leading contributor. The dominant disciplines within the artificial blood vessels sector include engineering, biomedical sciences, materials science, biomaterials science, and surgery, with surgery experiencing the most rapid expansion.

CONCLUSIONS

This study is the inaugural effort to bibliometrically analyze and visualize the scholarly output in the domain of artificial blood vessels. It provides clinicians and researchers with a reliable synopsis of the field's current state, offering a reference point for existing research and suggesting new avenues for future investigations.

In vitro erythropoiesis: the emerging potential of induced pluripotent stem cells (iPSCs)

Due to global blood shortages and restricted donor blood storage, the focus has switched to the in vitro synthesis of red blood cells (RBCs) from induced pluripotent stem cells (iPSCs) as a potential solution. Many processes are required to synthesize RBCs from iPSCs, including the production of iPSCs from human or animal cells, differentiation of iPSCs into hematopoietic stem cells, culturing, and maturation of the hematopoietic stem cells (HSC) to make functional erythrocytes. Previous investigations on the in vitro production of erythrocytes have shown conflicting results. Some studies have demonstrated substantial yields of functional erythrocytes, whereas others have observed low yields of enucleated cells. Before large-scale in vitro RBC production can be achieved, several challenges which have limited its application in the clinic must be overcome. These issues include optimizing differentiation techniques to manufacture vast amounts of functional RBCs, upscaling the manufacturing process, cost-effectiveness, and assuring the production of RBCs with good manufacturing practices (GMP) before they can be used for therapeutic purposes.

The cell replacement therapeutic potential of human pluripotent stem cells

INTRODUCTION

The remarkable ability of human pluripotent stem cells (hPSCs) to differentiate into specialized cells of the human body emphasizes their immense potential in treating various diseases. Advances in hPSC technology are paving the way for personalized and allogeneic cell-based therapies. The first-in-human studies showed improved treatment of diseases with no adverse effects, which encouraged the industrial production of this type of medicine. To ensure the quality, safety and efficacy of hPSC-based products throughout their life cycle, it is important to monitor and control their clinical translation through good practices (GxP) regulations. Understanding these rules in advance will help ensure that the industrial development of hPSC-derived products for widespread clinical implementation is feasible and progresses rapidly.

AREAS COVERED

In this review, we discuss the key translational obstacles of hPSCs, outline the current hPSC-based clinical trials, and present a workflow for putative clinical hPSC-based products. Finally, we highlight some future therapeutic opportunities for hPSC-derivatives.

EXPERT OPINION

hPSC-based products continue to show promise for the treatment of a variety of diseases. While clinical trials support the relative safety and efficacy of hPSC-based products, further investigation is required to explore the clinical challenges and achieve exclusive regulations for hPSC-based cell therapies.

From in vivo models to in vitro bioengineered neuromuscular junctions for the study of Charcot-Marie-Tooth disease

Peripheral neuropathies are disorders affecting the peripheral nervous system. Among them, Charcot-Marie-Tooth disease is an inherited sensorimotor neuropathy for which no effective treatment exists yet. Research on Charcot-Marie-Tooth disease has been hampered by difficulties in accessing relevant cells, such as sensory and motor neurons, Schwann cells, and myocytes, which interact at the neuromuscular junction, the specialized synapses formed between nerves and skeletal muscles. This review first outlines the various in vivo models and methods used to study neuromuscular junction deficiencies in Charcot-Marie-Tooth disease. We then explore novel in vitro techniques and models, including complex hiPSC-derived cultures, which offer promising isogenic and reproducible neuromuscular junction models. The adaptability of in vitro culture methods, including cell origin, cell-type combinations, and choice of culture format, adds complexity and excitement to this rapidly evolving field. This review aims to recapitulate available tools for studying Charcot-Marie-Tooth disease to understand its pathophysiological mechanisms and test potential therapies.

Digital PCR-Based Gene Expression Analysis Using a Highly Multiplexed Assay with Universal Detection Probes to Study Induced Pluripotent Stem Cell Differentiation into Cranial Neural Crest Cells

Induced pluripotent stem cells (iPSCs) have the potential to differentiate into any cell type, offering a valuable tool for research in developmental biology, regenerative medicine, and disease modeling. In this study, iPSCs were differentiated into cranial neural crest cells (CNCCs) over a 14-day period. RNA was extracted from these cells at day 0 (iPSCs), day 7, and day 14 to evaluate successful differentiation through the expression analysis of pluripotency and CNCC marker genes.A key focus was the conversion of existing qPCR assays into multiplexed RT-dPCR assays utilizing universal detection probes for precise gene expression analysis during the differentiation of induced pluripotent stem cells (iPSCs) into cranial neural crest cells (CNCCs). We aimed to leverage the superior precision, sensitivity, and multiplexing-degree of dPCR, particularly in quantifying low-abundance targets. We conducted a comparative analysis of the temporal expression patterns of crucial marker genes using both qPCR and dPCR.Our experiments revealed that the four five-plex dPCR assays could successfully detect and quantify the pluripotency and CNCC marker genes and evaluate CNCC differentiation. We observed the expected downregulation of pluripotency genes during differentiation. Conversely, the upregulation of CNCC markers validates the successful differentiation process. In conclusion, SYBR Green I gene expression qPCR assays can be readily converted into multiplex dPCR assays using universal detection probes.Overall, this work underscores the potential of dPCR as a valuable tool for molecular profiling in stem cell research, offering robust, precise, and efficient gene expression analysis. The findings suggest that while qPCR remains a reliable method for routine applications, dPCR provides particular advantages for high-precision, low-sample input studies, expanding the analytical toolbox for stem cell differentiation and gene expression research.

Stem Cell Therapy for the Treatment of Amyotrophic Lateral Sclerosis: Comparison of the Efficacy of Mesenchymal Stem Cells, Neural Stem Cells, and Induced Pluripotent Stem Cells

BACKGROUND/OBJECTIVES

Amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, is a debilitating, incurable neurodegenerative disorder characterised by motor neuron death in the spinal cord, brainstem, and motor cortex. With an incidence rate of about 4.42 cases per 100,000 people annually, ALS severely impacts motor function and quality of life, causing progressive muscle atrophy, spasticity, paralysis, and eventually death. The cause of ALS is largely unknown, with 90% of cases being sporadic and 10% familial. Current research targets molecular mechanisms of inflammation, excitotoxicity, aggregation-prone proteins, and proteinopathy.

METHODS

This review evaluates the efficacy of three stem cell types in ALS treatment: mesenchymal stem cells (MSCs), neural stem cells (NSCs), and induced pluripotent stem cells (iPSCs).

RESULTS

MSCs, derived from various tissues, show neuroprotective and regenerative qualities, with clinical trials suggesting potential benefits but limited by small sample sizes and non-randomised designs. NSCs, isolated from the fetal spinal cord or brain, demonstrate promise in animal models but face functional integration and ethical challenges. iPSCs, created by reprogramming patient-specific somatic cells, offer a novel approach by potentially replacing or supporting neurons. iPSC therapy addresses ethical issues related to embryonic stem cells but encounters challenges regarding genotoxicity and epigenetic irregularities, somatic cell sources, privacy concerns, the need for extensive clinical trials, and high reprogramming costs.

CONCLUSIONS

This research is significant for advancing ALS treatment beyond symptomatic relief and modest survival extensions to actively modifying disease progression and improving patient outcomes. Successful stem cell therapies could lead to new ALS treatments, slowing motor function loss and reducing symptom severity.

Ethical frontiers in liver transplantation

Liver transplantation represents a pivotal intervention in the management of end-stage liver disease, offering a lifeline to countless patients. Despite significant strides in surgical techniques and organ procurement, ethical dilemmas and debates continue to underscore this life-saving procedure. Navigating the ethical terrain surrounding this complex procedure is hence paramount. Dissecting the nuances of ethical principles of justice, autonomy and beneficence that underpin transplant protocols worldwide, we explore the modern challenges that plaques the world of liver transplantation. We investigate the ethical dimensions of organ transplantation, focusing on allocation, emerging technologies, and decision-making processes. PubMed, Scopus, Web of Science, Embase and Central were searched from database inception to February 29, 2024 using the following keywords: "liver transplant", "transplantation", "liver donation", "liver recipient", "organ donation" and "ethics". Information from relevant articles surrounding ethical discussions in the realm of liver transplantation, especially with regards to organ recipients and allocation, organ donation, transplant tourism, new age technologies and developments, were extracted. From the definition of death to the long term follow up of organ recipients, liver transplantation has many ethical quandaries. With new transplant techniques, societal acceptance and perceptions also play a pivotal role. Cultural, religious and regional factors including but not limited to beliefs, wealth and accessibility are extremely influential in public attitudes towards donation, xenotransplantation, stem cell research, and adopting artificial intelligence. Understanding and addressing these perspectives whilst upholding bioethical principles is essential to ensure just distribution and fair allocation of resources. Robust regulatory oversight for ethical sourcing of organs, ensuring good patient selection and transplant techniques, and high-quality long-term surveillance to mitigate risks is essential. Efforts to promote equitable access to transplantation as well as prioritizing patients with true needs are essential to address disparities. In conclusion, liver transplantation is often the beacon of hope for individuals suffering from end-stage liver disease and improves quality of life. The ethics related to transplantation are complex and multifaceted, considering not just the donor and the recipient, but also the society as a whole.

Integrating Physical and Biochemical Cues for Muscle Engineering: Scaffolds and Graft Durability

Muscle stem cells (MuSCs) are essential for skeletal muscle regeneration, influenced by a complex interplay of mechanical, biochemical, and molecular cues. Properties of the extracellular matrix (ECM) such as stiffness and alignment guide stem cell fate through mechanosensitive pathways, where forces like shear stress translate into biochemical signals, affecting cell behavior. Aging introduces senescence which disrupts the MuSC niche, leading to reduced regenerative capacity via epigenetic alterations and metabolic shifts. Transplantation further challenges MuSC viability, often resulting in fibrosis driven by dysregulated fibro-adipogenic progenitors (FAPs). Addressing these issues, scaffold designs integrated with pharmacotherapy emulate ECM environments, providing cues that enhance graft functionality and endurance. These scaffolds facilitate the synergy between mechanotransduction and intracellular signaling, optimizing MuSC proliferation and differentiation. Innovations utilizing human pluripotent stem cell-derived myogenic progenitors and exosome-mediated delivery exploit bioactive properties for targeted repair. Additionally, 3D-printed and electrospun scaffolds with adjustable biomechanical traits tackle scalability in treating volumetric muscle loss. Advanced techniques like single-cell RNA sequencing and high-resolution imaging unravel muscle repair mechanisms, offering precise mapping of cellular interactions. Collectively, this interdisciplinary approach fortifies tissue graft durability and MuSC maintenance, propelling therapeutic strategies for muscle injuries and degenerative diseases.

Standardization and optimization of the hiPSC-based PluriLum assay for detection of embryonic and developmental toxicants

New approach methodologies (NAMs) for predicting embryotoxicity and developmental toxicity are urgently needed for generating human relevant data, while reducing turnover time and costs, and alleviating ethical concerns related to the use of animal models. We have previously developed the PluriLum assay, a NKX2.5-reporter gene 3D model using human-induced pluripotent stem cells (hiPSCs) that are genetically modified to enable the assessment of adverse effects of chemicals on the early-stage embryo. Aiming at improving the predictive value of the PluriLum assay for future screening purposes, we sought to introduce standardization steps to the protocol, improving the overall robustness of the PluriLum assay, as well as a shortening of the assay protocol. First, we showed that the initial size of embryoid bodies (EBs) is crucial for a proper differentiation into cardiomyocytes and overall reproducibility of the assay. When the starting diameter of the EBs exceeds 500 µm, robust differentiation can be anticipated. In terms of reproducibility, exposure to the fungicide epoxiconazole at smaller initial diameters resulted in a larger variation of the derived data, compared to more reliable concentration-response curves obtained using spheroids with larger initial diameters. We further investigated the ideal length of the differentiation protocol, resulting in a shortening of the PluriLum assay by 24 h to 7 days. Following exposure to the teratogens all-trans and 13-cis retinoic acid, both cardiomyocyte contraction and measurement of NKX2.5-derived luminescence were recorded with a similar or increased sensitivity after 6 days of differentiation when compared to the original 7 days. Finally, we have introduced an efficient step for enzymatic dissociation of the EBs at assay termination. This allows for an even splitting of the individual EBs and testing of additional endpoints other than the NKX2.5-luciferase reporter, which was demonstrated in this work by the simultaneous assessment of ATP levels. In conclusion, we have introduced standardizations and streamlined the PluriLum assay protocol to improve its suitability as a NAM for screening of a large number of chemicals for developmental toxicity testing.

Testicular immunity

The testis is a unique environment where immune responses are suppressed to allow the development of sperm that possess autoimmunogenic antigens. There are several contributors responsible for testicular immune privilege, including the blood-testis barrier, testicular immune cells, immunomodulation by Sertoli cells, and high levels of steroid hormones. Despite multiple mechanisms in place to regulate the testicular immune environment, pathogens that disrupt testicular immunity can lead to long-term effects such as infertility. If testicular immunity is disturbed, autoimmune reactions can also occur, leading to aberrant immune cell infiltration and subsequent attack of autoimmunogenic germ cells. Here we discuss cellular and molecular factors underlying testicular immunity and how testicular infection or autoimmunity compromise immune privilege. We also describe infections and autoimmune diseases that impact the testis. Further research into testicular immunity will reveal how male fertility is maintained and will help update therapeutic strategies for infertility and other testicular disorders.

TGFβ family signaling in human stem cell self-renewal and differentiation

Human stem cells are undifferentiated cells with the capacity for self-renewal and differentiation into distinct cell lineages, playing important role in the development and maintenance of diverse tissues and organs. The microenvironment of stem cell provides crucial factors and components that exert significant influence over the determination of cell fate. Among these factors, cytokines from the transforming growth factor β (TGFβ) superfamily, including TGFβ, bone morphogenic protein (BMP), Activin and Nodal, have been identified as important regulators governing stem cell maintenance and differentiation. In this review, we present a comprehensive overview of the pivotal roles played by TGFβ superfamily signaling in governing human embryonic stem cells, somatic stem cells, induced pluripotent stem cells, and cancer stem cells. Furthermore, we summarize the latest research and advancements of TGFβ family in various cancer stem cells and stem cell-based therapy, discussing their potential clinical applications in cancer therapy and regeneration medicine.

Breaking the mold: 3D cell cultures reshaping the future of cancer research

Despite extensive efforts to unravel tumor behavior and develop anticancer therapies, most treatments fail when advanced to clinical trials. The main challenge in cancer research has been the absence of predictive cancer models, accurately mimicking the tumoral processes and response to treatments. The tumor microenvironment (TME) shows several human-specific physical and chemical properties, which cannot be fully recapitulated by the conventional 2D cell cultures or the in vivo animal models. These limitations have driven the development of novel in vitro cancer models, that get one step closer to the typical features of in vivo systems while showing better species relevance. This review introduces the main considerations required for developing and exploiting tumor spheroids and organoids as cancer models. We also detailed their applications in drug screening and personalized medicine. Further, we show the transition of these models into novel microfluidic platforms, for improved control over physiological parameters and high-throughput screening. 3D culture models have provided key insights into tumor biology, more closely resembling the in vivo TME and tumor characteristics, while enabling the development of more reliable and precise anticancer therapies.

Comparative analysis of regulations and studies on stem cell therapies: focusing on induced pluripotent stem cell (iPSC)-based treatments

Stem cell therapies have emerged as a promising approach in regenerative medicine, demonstrating potential in personalized medicine, disease modeling, and drug discovery. Therapies based on induced pluripotent stem cells (iPSCs) particularly stand out for their ability to differentiate into various cell types while avoiding ethical concerns. However, the development and application of these therapies are influenced by varying regulatory frameworks across countries. This study provides a comparative analysis of regulations and research on stem cell therapies in key regions: The European Union (EU), Switzerland, South Korea, Japan, and the United States. First, the study reviews the regulatory frameworks on stem cell therapies. The EU and Switzerland maintain rigorous guidelines that prioritize safety and ethical considerations, which can hinder innovation. In contrast, the United States adopts a more flexible regulatory stance, facilitating the rapid development of stem cell therapies. South Korea and Japan take a balanced approach by incorporating practices from both regimes. These regulatory differences reflect each country's unique priorities and impact the pace and scope of stem cell therapy development. Moreover, the study examines global trends in clinical trials on stem cell treatments based on data obtained from two sources: ClinicalTrials.gov and ICTRP. Findings indicate a significant growth in the number of clinical trials since 2008, particularly in that involving iPSCs. Therapeutic studies involving iPSCs predominantly target conditions affecting the cardiovascular and nervous systems which are considered vital. The results put emphasis on the safety of stem cell treatments. Meanwhile, the number of such trials also varies by country. The United States and Japan, where relatively flexible guidelines on stem cell research are adopted, are in a leading position. However, countries in the EU fall behind with rigorous regulations imposed. This reflects the need for more flexible regulatory guidance for active development of stem cell therapies. The findings underscore the importance of legal frameworks in facilitating innovation while ensuring safety. Regulatory agencies in different countries should collaborate to achieve a balanced global standard to ensure the safe and efficient advancement of stem cell therapies. Global regulatory convergence will promote international collaboration in research and the applicability of new treatments.

Microphysiological systems to advance human pathophysiology and translational medicine

Microphysiological systems (MPS) or "organ-on-a-chip" models are sophisticated tools that harness techniques from cell biology, tissue engineering, and microengineering to recapitulate human physiology. Typically, MPS are biofabricated three-dimensional (3-D) tissue constructs integrated into platforms designed to mimic the tissue microenvironment and provide functional outputs. Over the past decade, researchers have endeavored to manufacture high-throughput, high-fidelity MPS models of all major human organs. By incorporating patient-derived cells, researchers have produced biomimetic models of tissues with disease-linked genetic mutations capable of exhibiting patient heterogeneity. This work has demonstrated that MPS more closely model organotypic function and pathophysiology than traditional two-dimensional (2-D) culture systems. Moreover, investigators have shown that human MPS are better predictors of drug efficacy and toxicity than animal models. Thus, MPS have emerged as a promising candidate to improve the efficacy and safety of preclinical trials. In this mini-review, we provide an overview of current advances in MPS models, their applications in mechanistic research, and relevance to drug screening. Finally, we discuss current investments in MPS development by the United States federal government and research institutions around the world to advance translational medicine.

Advances in retinal pigment epithelial cell transplantation for retinal degenerative diseases

Retinal degenerative diseases are a leading cause of vision loss and blindness globally, impacting millions. These diseases result from progressive damage to retinal pigment epithelial (RPE) cells for which no curative or palliative treatments exist. Cell therapy, particularly RPE transplantation, has emerged as a promising strategy for vision restoration. This review provides a comprehensive overview of the recent advancements in clinical trials related to RPE transplantation. We discuss scaffold-free and scaffold-based approaches, including RPE cell suspensions and pre-organized RPE monolayers on biomaterial scaffolds. Key considerations, such as the form and preparation of RPE implants, delivery devices, strategies, and biodegradability of scaffolds, are examined. The article also explores the challenges and opportunities in RPE scaffold development, emphasising the crucial need for functional integration, immunomodulation, and long-term biocompatibility to ensure therapeutic efficacy. We also highlight ongoing efforts to optimise RPE transplantation methods and their potential to address retinal degenerative diseases.

Advancing diabetes management: Exploring pancreatic beta-cell restoration's potential and challenges

Diabetes mellitus, characterized by chronic hyperglycemia due to insulin deficiency or resistance, poses a significant global health burden. Central to its pathogenesis is the dysfunction or loss of pancreatic beta cells, which are res-ponsible for insulin production. Recent advances in beta-cell regeneration research offer promising strategies for diabetes treatment, aiming to restore endogenous insulin production and achieve glycemic control. This review explores the physiological basis of beta-cell function, recent scientific advan-cements, and the challenges in translating these findings into clinical applications. It highlights key developments in stem cell therapy, gene editing technologies, and the identification of novel regenerative molecules. Despite the potential, the field faces hurdles such as ensuring the safety and long-term efficacy of regen-erative therapies, ethical concerns around stem cell use, and the complexity of beta-cell differentiation and integration. The review highlights the importance of interdisciplinary collaboration, increased funding, the need for patient-centered approaches and the integration of new treatments into comprehensive care strategies to overcome these challenges. Through continued research and collaboration, beta-cell regeneration holds the potential to revolutionize diabetes care, turning a chronic condition into a manageable or even curable disease.

Bioengineering breakthroughs: The impact of stem cell models on advanced therapy medicinal product development

The burgeoning field of bioengineering has witnessed significant strides due to the advent of stem cell models, particularly in their application in advanced therapy medicinal products (ATMPs). In this review, we examine the multifaceted impact of these developments, emphasizing the potential of stem cell models to enhance the sophistication of ATMPs and to offer alternatives to animal testing. Stem cell-derived tissues are particularly promising because they can reshape the preclinical landscape by providing more physiologically relevant and ethically sound platforms for drug screening and disease modelling. We also discuss the critical challenges of reproducibility and accuracy in measurements to ensure the integrity and utility of stem cell models in research and application. Moreover, this review highlights the imperative of stem cell models to align with regulatory standards, ensuring using stem cells in ATMPs translates into safe and effective clinical therapies. With regulatory approval serving as a gateway to clinical adoption, the collaborative efforts between scientists and regulators are vital for the progression of stem cell applications from bench to bedside. We advocate for a balanced approach that nurtures innovation within the framework of rigorous validation and regulatory compliance, ensuring that stem cell-base solutions are maximized to promote public trust and patient health in ATMPs.

Reassessment of marker genes in human induced pluripotent stem cells for enhanced quality control

Human induced pluripotent stem cells (iPSCs) have great potential in research, but pluripotency testing faces challenges due to non-standardized methods and ambiguous markers. Here, we use long-read nanopore transcriptome sequencing to discover 172 genes linked to cell states not covered by current guidelines. We validate 12 genes by qPCR as unique markers for specific cell fates: pluripotency (CNMD, NANOG, SPP1), endoderm (CER1, EOMES, GATA6), mesoderm (APLNR, HAND1, HOXB7), and ectoderm (HES5, PAMR1, PAX6). Using these genes, we develop a machine learning-based scoring system, "hiPSCore", trained on 15 iPSC lines and validated on 10 more. hiPSCore accurately classifies pluripotent and differentiated cells and predicts their potential to become specialized 2D cells and 3D organoids. Our re-evaluation of cell fate marker genes identifies key targets for future studies on cell fate assessment. hiPSCore improves iPSC testing by reducing time, subjectivity, and resource use, thus enhancing iPSC quality for scientific and medical applications.

Unlocking the therapeutic potential: odyssey of induced pluripotent stem cells in precision cell therapies

This review explores the application of induced pluripotent stem cells (iPSCs) in regenerative medicine. The therapeutic significance of iPSC-derived cell therapy within regenerative medicine, emphasizes their reprogramming process and crucial role in cellular differentiation while setting the purpose and scope for the comprehensive exploration of iPSC-derived cell therapy. The subsequent sections intricately examine iPSC-derived cell therapy, unraveling the diverse derivatives of iPSCs and striking a delicate balance between advantages and limitations in therapeutic applications. Mechanisms of action, revealing how iPSC-derived cells seamlessly integrate into tissues, induce regeneration, and contribute to disease modeling and drug screening advancements is discussed. The analysis extends to clinical trials, shedding light on outcomes, safety considerations, and ethical dimensions. Challenges and concerns, including the risk of tumorigenesis and scalability issues, are explored. The focus extends to disease-specific applications, showcasing iPSC-derived cell therapy as a promising avenue for various medical conditions, supported by illustrative case studies. Future directions and research needs are outlined, identifying areas for further exploration, safety considerations and potential enhancements that will shape the future landscape of iPSC-derived therapies. In conclusion, this review provides a significant understanding of iPSC-derived cell therapy's status that contemplates the implications for regenerative medicine and personalized treatment using iPSCs, offering a comprehensive perspective on the evolving field within the confines of a dynamic and promising scientific frontier.

Stem cell therapies for chronic obstructive pulmonary disease: mesenchymal stem cells as a promising treatment option

Chronic obstructive pulmonary disease(COPD) is an inflammatory disease characterized by the progressive and irreversible structural and functional damage of lung tissue. Although COPD is a significant global disease burden, the available treatments only ameliorate the symptoms, but cannot reverse lung damage. Researchers in regenerative medicine have examined the use of stem cell transplantation for treatment of COPD and other diseases because these cells have the potential for unlimited self-renewal and the ability to undergo directed differentiation. Stem cells are typically classified as embryonic stem cells, induced pluripotent stem cells, and adult stem cells (which includes mesenchymal stem cells [MSCs]), each with its own advantages and disadvantages regarding applications in regenerative medicine. Although the heterogeneity and susceptibility to senescence of MSCs make them require careful consideration for clinical applications. However, the low tumourigenicity and minimal ethical concerns of MSCs make them appear to be excellent candidates. This review summarizes the characteristics of various stem cell types and describes their therapeutic potential in the treatment of COPD, with a particular emphasis on MSCs. We aim to facilitate subsequent in-depth research and preclinical applications of MSCs by providing a comprehensive overview.

Innovative Strategies in 3D Bioprinting for Spinal Cord Injury Repair

Spinal cord injury (SCI) is a catastrophic condition that disrupts neurons within the spinal cord, leading to severe motor and sensory deficits. While current treatments can alleviate pain, they do not promote neural regeneration or functional recovery. Three-dimensional (3D) bioprinting offers promising solutions for SCI repair by enabling the creation of complex neural tissue constructs. This review provides a comprehensive overview of 3D bioprinting techniques, bioinks, and stem cell applications in SCI repair. Additionally, it highlights recent advancements in 3D bioprinted scaffolds, including the integration of conductive materials, the incorporation of bioactive molecules like neurotrophic factors, drugs, and exosomes, and the design of innovative structures such as multi-channel and axial scaffolds. These innovative strategies in 3D bioprinting can offer a comprehensive approach to optimizing the spinal cord microenvironment, advancing SCI repair. This review highlights a comprehensive understanding of the current state of 3D bioprinting in SCI repair, offering insights into future directions in the field of regenerative medicine.

Induced pluripotent stem cell therapies in heart failure treatment: a meta-analysis and systematic review

Background: Heart failure (HF) causes over 266,400 deaths annually. Despite treatment advancements, HF mortality remains high. Induced pluripotent stem cells (iPSCs) offer promising new options. This review assesses iPSC-based treatments for HF.Method: the review included studies from PubMed, ScienceDirect and Web of Science.Results: Analysis of 25 studies with 553 animals showed a baseline ejection fraction (EF) of 39.2 ± 8.9%. iPSC treatment significantly improved EF (MD = 8.6, p < 0.001) and fractional shortening (MD = 6.38, p < 0.001), and reduced ventricular remodeling without increasing arrhythmia risk.Conclusion: iPSC-based therapy improves heart function and reduces ventricular volumes in HF animal models, aligning with promising early clinical trial outcomes.

Innovative Bioscaffolds in Stem Cell and Regenerative Therapies for Corneal Pathologies

Corneal diseases, which can result in substantial visual impairment and loss of vision, are an important worldwide health issue. The aim of this review was to investigate the novel application of bioscaffolds in stem cell and regenerative treatments for the treatment of corneal disorders. The current literature reports that organic and artificial substances create bioscaffolds that imitate the inherent structure of the cornea, facilitating the attachment, growth, and specialization of stem cells. Sophisticated methods such as electrospinning, 3D bioprinting, and surface modification have been reported to enhance the characteristics of the scaffold. These bioscaffolds have been shown to greatly improve the survival of stem cells and facilitate the regrowth of corneal tissue in both laboratory and live animal experiments. In addition, the incorporation of growth factors and bioactive compounds within the scaffolds can promote a favorable milieu for corneal regeneration. To summarize, the advancement of these groundbreaking bioscaffolds presents a hopeful treatment strategy for the regeneration of the cornea, which has the potential to enhance the results for individuals suffering from corneal disorders. This study highlights the possibility of utilizing the fields of biomaterials science and stem cell treatment to tackle medical demands that have not yet been satisfied in the field of ophthalmology.

The application potential of iMSCs and iMSC-EVs in diseases

The immune system, functioning as the body's "defense army", plays a role in surveillance, defense. Any disruptions in immune system can lead to the development of immune-related diseases. Extensive researches have demonstrated the crucial immunoregulatory role of mesenchymal stem cells (MSCs) in these diseases. Of particular interest is the ability to induce somatic cells under specific conditions, generating a new cell type with stem cell characteristics known as induced pluripotent stem cell (iPSC). The differentiation of iPSCs into MSCs, specifically induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs), hold promise as a potential solution to the challenges of MSCs, potentially serving as an alternative to traditional drug therapies. Moreover, the products of iMSCs, termed induced pluripotent stem cell-derived mesenchymal stem cell-derived extracellular vesicles (iMSC-EVs), may exhibit functions similar to iMSCs. With the biological advantages of EVs, they have become the focus of "cell-free therapy". Here, we provided a comprehensive summary of the biological impact of iMSCs on immune cells, explored the applications of iMSCs and iMSC-EVs in diseases, and briefly discussed the fundamental characteristics of EVs. Finally, we overviewed the current advantages and challenges associated with iMSCs and iMSC-EVs. It is our hope that this review related to iMSCs and iMSC-EVs will contribute to the development of new approaches for the treatment of diseases.

Ensuring safety and efficacy in combination products: regulatory challenges and best practices

Combination products, amalgamating drugs, biologics, and medical devices, have revolutionized the healthcare landscape with their potential for innovative therapies. However, the intersection of diverse components within these products presents a complex regulatory environment, demanding rigorous attention to safety and efficacy. This article delves into the intricate landscape of regulatory considerations, safety, and efficacy assessments pertaining to combination products-a category at the intersection of drugs, devices, and biologics. The regulatory framework, primarily governed by the U.S. Food and Drug Administration (FDA), necessitates a nuanced classification determining the regulatory pathway. Collaboration between diverse regulatory centers, such as the Center for Drug Evaluation and Research (CDER) and the Center for Devices and Radiological Health (CDRH), underscores the integrated approach required for these innovative healthcare solutions. Safety considerations unravel the potential risks and adverse events associated with combining diverse components, emphasizing the need for robust risk assessment and mitigation strategies. The evaluation of efficacy involves sophisticated methodologies, clinical trials, and post-market surveillance, with recent advancements incorporating digital technologies. This comprehensive exploration aims to contribute to the evolving understanding and best practices in the regulatory and scientific realms, fostering collaboration and innovation in the development and assessment of combination products.

Induced pluripotent stem cell models as a tool to investigate and test fluid biomarkers in Alzheimer's disease and frontotemporal dementia

Neurodegenerative diseases are increasing in prevalence and comprise a large socioeconomic burden on patients and their caretakers. The need for effective therapies and avenues for disease prevention and monitoring is of paramount importance. Fluid biomarkers for neurodegenerative diseases have gained a variety of uses, including informing participant selection for clinical trials, lending confidence to clinical diagnosis and disease staging, determining prognosis, and monitoring therapeutic response. Their role is expected to grow as disease-modifying therapies start to be available to a broader range of patients and as prevention strategies become established. Many of the underlying molecular mechanisms of currently used biomarkers are incompletely understood. Animal models and in vitro systems using cell lines have been extensively employed but face important translatability limitations. Induced pluripotent stem cell (iPSC) technology, where a theoretically unlimited range of cell types can be reprogrammed from peripheral cells sampled from patients or healthy individuals, has gained prominence over the last decade. It is a promising avenue to study physiological and pathological biomarker function and response to experimental therapeutics. Such systems are amenable to high-throughput drug screening or multiomics readouts such as transcriptomics, lipidomics, and proteomics for biomarker discovery, investigation, and validation. The present review describes the current state of biomarkers in the clinical context of neurodegenerative diseases, with a focus on Alzheimer's disease and frontotemporal dementia. We include a discussion of how iPSC models have been used to investigate and test biomarkers such as amyloid-β, phosphorylated tau, neurofilament light chain or complement proteins, and even nominate novel biomarkers. We discuss the limitations of current iPSC methods, mentioning alternatives such as coculture systems and three-dimensional organoids which address some of these concerns. Finally, we propose exciting prospects for stem cell transplantation paradigms using animal models as a preclinical tool to study biomarkers in the in vivo context.

Potential Plausible Role of Stem Cell for Treating Depressive Disorder: a Retrospective Review

Depression poses a significant threat to global physical and mental health, impacting around 3.8% of the population with a rising incidence. Current treatment options primarily involve medication and psychological support, yet their effectiveness remains limited, contributing to high relapse rates. There is an urgent need for innovative and more efficacious treatment modalities. Stem cell therapy, a promising avenue in regenerative medicine for a spectrum of neurodegenerative conditions, has recently garnered attention for its potential application in depression. While much of this work remains preclinical, it has demonstrated considerable promise. Identified mechanisms underlying the antidepressant effects of stem cell therapy encompass the stimulation of neurotrophic factors, immune function modulation, and augmented monoamine levels. Nonetheless, these pathways and other undiscovered mechanisms necessitate further investigation. Depression fundamentally manifests as a neurodegenerative disorder. Given stem cell therapy's success in addressing a range of neurodegenerative pathologies, it opens the door to explore its application in depression treatment. This exploration may include repairing damaged nerves directly or indirectly and inhibiting neurotoxicity. Nevertheless, significant challenges must be overcome before stem cell therapies can be applied clinically. Successful resolution of these issues will ultimately determine the feasibility of incorporating stem cell therapies into the clinical landscape. This narrative review provides insights into the progress of research, potential avenues for exploration, and the prevailing challenges in the implementation of stem cell therapy for treatment of depression.

Exosomes: The endogenous nanomaterials packed with potential for diagnosis and treatment of neurologic disorders

Neurologic disorders (NDs) are serious diseases that threaten public health. However, due to the complex pathogenesis and significant individual differences in traditional treatments, specific treatment methods for NDs are still lacking. Exosomes, the smallest extracellular vesicles secreted by eukaryotic cells, are receiving increasing attention in the field of NDs. They contain misfolded proteins related to various NDs, including amyloid-beta, Tau proteins, and α-synuclein, indicating their promising roles in the diagnosis and treatment of NDs. In this review, an overview of the biogenesis, composition, and biological functions of exosomes is provided. Moreover, we summarize their potential roles in the pathogenesis of three prevalent NDs (including Alzheimer's disease, Ischemic stroke, and Parkinson's disease). On this basis, the diagnostic potential and therapeutic value of exosomes carrying various bioactive molecules are discussed in detail. Also, the concerns and perspectives of exosome-based diagnosis and therapy are discussed.

Neuronal Cell Differentiation of iPSCs for the Clinical Treatment of Neurological Diseases

Current chemical treatments for cerebrovascular disease and neurological disorders have limited efficacy in tissue repair and functional restoration. Induced pluripotent stem cells (iPSCs) present a promising avenue in regenerative medicine for addressing neurological conditions. iPSCs, which are capable of reprogramming adult cells to regain pluripotency, offer the potential for patient-specific, personalized therapies. The modulation of molecular mechanisms through specific growth factor inhibition and signaling pathways can direct iPSCs' differentiation into neural stem cells (NSCs). These include employing bone morphogenetic protein-4 (BMP-4), transforming growth factor-beta (TGFβ), and Sma-and Mad-related protein (SMAD) signaling. iPSC-derived NSCs can subsequently differentiate into various neuron types, each performing distinct functions. Cell transplantation underscores the potential of iPSC-derived NSCs to treat neurodegenerative diseases such as Parkinson's disease and points to future research directions for optimizing differentiation protocols and enhancing clinical applications.

An induced pluripotent stem cell-based approach for hair follicle development and regeneration

Because hair loss is a common concern for many individuals, potential regenerative therapies of hair follicles have been extensively researched. Induced pluripotent stem cells (iPSCs) are a promising avenue for hair follicle regeneration. This review explores current iPSC-based approaches and highlights their potential applications and challenges in hair restoration. The principles of iPSC technology, iPSC differentiation into hair follicle precursor cells, and potential clinical implications for hair follicle regeneration are also discussed. This overview of iPSCs and their applications aims to contribute to our understanding of their role in hair restoration and potential future therapeutic applications.