Tracheal Regeneration: Recent Progress in the Application of Stem Cells in Tracheal Bioengineering.

To bring the notion of cardiac regenerative medicine to fruition, researchers have tried to determine which stem cells, embryonic stem (ES) cells or somatic stem cells, are most suitable. Thus far, there is no clear indication which is better, because both have their own advantages and disadvantages. In 2006, murine induced pluripotent stem (iPS) cells were first established. Since then, basic research into the properties of iPS cells has continued apace. Originally, human iPS cells were generated from dermal fibroblasts by retrovirus-mediated gene transfer. Although this technique is sophisticated and easy to perform, the skin biopsy is accompanied by some bleeding and pain, and there may be some damage to the host genome because of retrovirus-mediated transgene integration. However, methods of producing iPS cells have improved steadily. For clinical application in the cardiovascular field, efficient methods that produce pluripotent stem cells that can differentiate into cardiomyocytes need to be developed. Existing methods for ES cells can be applied to iPS cells to obtain cardiomyocyte differentiation. In addition, existing purification methods can be used to obtain pure cardiomyocytes from a population of mixed cells. These techniques have themselves been the subject of extensive research, and continued advances are now making the clinical application of pluripotent stem cells a reality. We are at the forefront of medical innovations in the cardiovascular field based on the use of pluripotent stem cells.KeywordsES cellsiPS cellsCardiomyocyteDifferentiation

Lysosomal storage disorders (LSDs) are rare inborn errors of metabolism caused by defects in lysosomal function. These diseases are characterized by accumulation of completely or partially degraded substrates in the lysosomes leading to cellular dysfunction of the affected cells. Currently, enzyme replacement therapies (ERTs), treatments directed at substrate reduction (SRT), and hematopoietic stem cell (HSC) transplantation are the only treatment options for LSDs, and the effects of these treatments depend strongly on the type of LSD and the time of initiation of treatment. However, some of the LSDs still lack a durable and curative treatment. Therefore, a variety of novel treatments for LSD patients has been developed in the past few years. However, despite significant progress, the efficacy of some of these treatments remains limited because these therapies are often initiated after irreversible organ damage has occurred.Here, we provide an overview of the known effects of LSDs on stem cell function, as well as a synopsis of available stem cell-based cell and gene therapies that have been/are being developed for the treatment of LSDs. We discuss the advantages and disadvantages of use of hematopoietic stem cell (HSC), mesenchymal stem cell (MSC), and induced pluripotent stem cell (iPSC)-related (gene) therapies. An overview of current research data indicates that when stem cell and/or gene therapy applications are used in combination with existing therapies such as ERT, SRT, and chaperone therapies, promising results can be achieved, showing that these treatments may result in alleviation of existing symptoms and/or prevention of progression of the disease. All together, these studies offer some insight in LSD stem cell biology and provide a hopeful perspective for the use of stem cells. Further development and improvement of these stem cell (gene) combination therapies may greatly improve the current treatment options and outcomes of patients with a LSD.

Chapter 43 - Growth Factors and the Serum-free Culture of Human Pluripotent Stem Cells

Mthfd2 Modulates Mitochondrial Function and DNA Repair to Maintain the Pluripotency of Mouse Stem Cells

Cell transplantation is a promising treatment option for spinal cord injury (SCI). However, there is no consensus on the choice of carrier scaffolds to host the cells. This study aims to evaluate the efficacy of different material scaffold-mediated cell transplantation in treating SCI in rats. According to PRISMA’s principle, Embase, PubMed, Web of Science, and Cochrane databases were searched, and relevant literature was referenced. Only original research on cell transplantation plus natural or synthetic scaffolds in SCI rats was included. Direct and indirect evidence for improving hind limb motor function was pooled through meta-analysis. A subgroup analysis of some factors that may affect the therapeutic effect was conducted to understand the results fully. In total, 25 studies met the inclusion criteria, in which 293 rats received sham surgery, 78 rats received synthetic material scaffolds, and 219 rats received natural materials scaffolds. The network meta-analysis demonstrated that although synthetic scaffolds were slightly inferior to natural scaffolds in terms of restoring motor function in cell transplantation of SCI rats, no statistical differences were observed between the two (MD: −0.35; 95% CI −2.6 to 1.9). Moreover, the subgroup analysis revealed that the type and number of cells may be important factors in therapeutic efficacy (P < 0.01). Natural scaffolds and synthetic scaffolds are equally effective in cell transplantation of SCI rats without significant differences. In the future, the findings need to be validated in multicenter, large-scale, randomized controlled trials in clinical practice.Trial registration: Registration ID CRD42024459674 (PROSPERO).Graphical

Background. Medical students have a significant role in improving new perspective about stem cell application in treatment of incurable diseases; such as degenerative neurologic disorders. Methods. In this descriptive cross-sectional study conducted in 2019-2020, 424 medical students at Guilan University of Medical Sciences responded to a questionnaire. The questionnaire was included the questions about knowledge of medical students about application of stem cells in neurologic disorders and stem cells donation and their attitude as well. Exclusion criteria were reluctance to participate in study and less than 20% response to questionnaire. The convenience sampling method was used. Inclusion criteria were being a medical student and willingness to participate in the project. Data were analyzed using SPSS 20 by Pearson correlation, independent student t, one-way ANOVA, U-Mann-Whitney. Results. 49.5% and 43.2% of participants had very low and low knowledge about using the stem cell. The higher score of knowledge was related to higher education periods. 70.3% of medical students had moderate attitude toward using stem cell. Only 17% of them had known the state agencies and private centers of donation. 70.5% had moderate knowledge and 55.2% had moderate attitude toward the stem cell donation. There was a correlation between the knowledge and attitude toward its donation (p = 0.004, r = 0.14). Knowledge about stem cells donation had correlation with the knowledge about its application (p = 0.001, r = 0.161). Conclusion. Although the majority of medical students have very low knowledge about stem cell application in treatment of neurologic disorders, but their attitude toward using stem cell was moderate.

Introduction: Innovations in human pluripotent stem cell research and their application in therapeutics have seen a giant leap in the past decade. Patent applications related to human pluripotent stem cell generation, culture and differentiation show an ever-increasing trend worldwide with hundreds of patents being applied for every year. With the turn of the second decade in stem cell patenting, a review of the latest patents issued will be significant.Areas covered: The growing need in healthcare sector has revolutionized stem cell application in clinical therapeutics by extending in unprecedented dimensions. With the potential of being able to differentiate into any desired adult cell lineage, human pluripotent stem cells find a wide range of applicability in clinical as well as cosmetic therapy. Moreover, the recent innovation of isolating a disease-specific pluripotent stem cell has opened new horizons to stem cell application in cell therapy. This review gives an overview of significant international patents granted on innovations in human pluripotent stem cell differentiation methodologies between 2009 and 2014.Expert opinion: The discovery of human pluripotent stem cells and their immense potential in clinical therapeutics has increasingly channeled scientific research in their orientation. Although being widely used to fathom human physiology, the trend in stem cell application is slowly shifting toward disease-modeling, drug safety evaluation and toxicity-testing. And in order to probe those unexplored realms of stem cell applications, a unified approach from the scientific community is imperative.

Biodegradable scaffolds are widely used in soft tissue reconstruction to support tissue regeneration and reduce long-term complications, yet the comparative clinical effectiveness of natural and synthetic scaffolds remains unclear. This systematic review and meta-analysis evaluated outcomes including recurrence rate, healing time, hospitalization duration, and complications. Following PRISMA guidelines and PROSPERO registration, PubMed, Scopus, and Web of Science were searched for studies published between January 2015 and January 2026. Randomized controlled trials and cohort studies involving human participants undergoing soft tissue reconstruction were included. Nine studies across multiple surgical fields were analyzed. Pooled results showed a significantly lower recurrence rate with natural scaffolds compared to synthetic scaffolds (RR 0.30, 95% CI 0.12 to 0.73, p = 0.008), with no heterogeneity (I² = 0%). Healing time did not differ significantly between groups (standard mean difference [SMD] -0.13, 95% CI -0.53 to 0.27, I² = 55%). Hospitalization time showed no significant difference but had high heterogeneity (SMD -0.76, 95% CI -0.06 to 1.57, I² = 89%). Complication rates favored natural scaffolds but were not statistically significant (RR 0.69, 95% CI 0.33 to 1.45, I² = 60%). Sensitivity analysis confirmed stability of findings. Natural scaffolds reduce recurrence and show a favorable safety trend, while healing and hospitalization outcomes depend more on surgical context than scaffold type.

Intestinal disease is a common disease, which can cause serious digestion and absorption disorders, endanger the lives of patients and seriously affect the quality of life of people. Finding an effective treatment is a difficult problem at present, and stem cell therapy as a treatment has high application potential in intestinal-related diseases. This paper mainly summarizes the mechanism, research progress and future development trend of stem cells in the treatment of intestinal diseases in the past decade, hoping to provide a reference for future researchers in the research and application of stem cells and intestinal diseases. Stem cells, inflammatory bowel diseases, Crohn's disease, radiation-induced intestinal injury, radiation enterocolitis, and extracellular vesicles were used as search terms. Relevant references in the past ten years were searched in CNKI journal full-text database, PubMed database, VIP network and Wanfang medical network, and 80 literature studies meeting the requirements were finally included for review. This paper summarizes the research and application of stem cells in intestinal diseases from 2012 to 2021, and expounds on the specific mechanism of stem cells in the treatment of intestinal diseases. It has been found that stem cells can treat intestinal injury or inflammation in different ways. Future stem cells may also be used to reverse the natural aging of intestinal function, improve intestinal function, and strengthen gastrointestinal function.

Neurodegenerative diseases represent a growing public health challenge. Current medications treat symptoms, but none halt or retard neurodegeneration. The recent advent of pluripotent cell biology has opened new avenues for neurodegenerative disease research. The greatest potential for induced pluripotent cells derived from affected individuals is likely to be their utility for modeling and understanding the mechanisms underlying neurodegenerative processes, and for searching for new treatments, including cell replacement therapies. However, much work remains to be done before pluripotent cells can be used for preclinical and clinical applications. Here we discuss the challenges of generating specific neural cell subtypes from pluripotent stem cells, the use of pluripotent stem cells to model both cell-autonomous and non-cell-autonomous mechanisms of neurodegeneration, whether adult-onset neurodegeneration can be emulated in short-term cultures and the hurdles of cell replacement therapy. Progress in these four areas will substantially accelerate effective application of pluripotent stem cells.

Pluripotent stem cells (PSCs) can differentiate into specific cell types and thus hold great promise in regenerative medicine to treat certain diseases. Hence, several studies have been performed harnessing their salutary properties in regenerative medicine. Despite several challenges associated with the clinical applications of PSCs, worldwide efforts are harnessing their potential in the regeneration of damaged tissues. Several clinical trials have been performed using PSCs or their derivatives. However, the delay in publishing the data obtained in the trials has led to a lack of awareness about their outcomes, resulting in apprehension about cellular therapies. Here, the authors review the published papers containing data from recent clinical trials done with PSCs. PSC-derived extracellular vesicles hold great potential in regenerative therapy. Since published papers containing the data obtained in clinical trials on PSC-derived extracellular vesicles are not available yet, the authors have reviewed some of the pre-clinical work done with them.

Background: Clinical application of pluripotent stem cells and their tissue specific derivatives will require in vivo monitoring of engraftment and systemic distribution following transplantation. Clinical translation of molecular imaging, employing reporter gene (RG) technology, requires site-specific transgene insertion at safe harbor loci, such as AAVS1. Hypothesis: Zinc finger nuclease (ZFN)-mediated integration of a RG into the AAVS1 locus in human embryonic and induced pluripotent stem cells (hESCs and iPSCs) will allow monitoring of pluripotent stem cell-derived cardiomyocytes (hCMs and iCMs) in host myocardium. Methods and Results: ZFN technology was used to integrate a triple fusion RG, containing firefly luciferase (BLI), red fluorescent protein (RFP) and herpes simplex virus thymidine kinase (PET), under regulation of a constitutive ubiquitin promoter, into the AAVS1 locus of hESCs and iPSCs. hESCs and iPSCs monoclonal lines were then differentiated into hCMs and iCMs, respectively, under chemically defined conditions using CHIR and IWR small molecules to modulate Wnt pathway activity. Co-localization of cardiac phenotype and striated morphology was readily observed (Fig. A). Site-specific integration was confirmed by southern blot analysis. RG expression by BLI was maintained successfully over 3 months in vitro. The hCMs (n=6) and iCMs (n=1) were transplanted into murine myocardial injury model. Four weeks post-injury, LVEF was better preserved in all cell-treated vs. PBS-treated mice (26.50 ± 2.325 (N=6) vs. 15.40 ± 4.600 (N=3), p&lt;0.05). Robust in vivo expression of ZFN-edited BLI and PET signal of engraftment persisted for 4-weeks duration (Figs. B and C). Conclusion: This study demonstrates the successful use of ZFN-edited cells to confirm the engraftment of hCMs and iCMs. ZFN technology enables targeted site-specific insertion of RGs to allow clinical translation of molecular imaging in cell therapy.

Engineering Stem and Stromal Cell Therapies for Musculoskeletal Tissue Repair.

Injury of articular cartilage can cause osteoarthritis and seriously affect the physical and mental health of patients. Unfortunately, current surgical treatment techniques that are commonly used in the clinic cannot regenerate articular cartilage. Regenerative medicine involving stem cells has entered a new stage and is considered the most promising way to regenerate articular cartilage. In terms of theories on the mechanism, it was thought that stem cell-mediated articular cartilage regeneration was achieved through the directional differentiation of stem cells into chondrocytes. However, recent evidence has shown that the stem cell secretome plays an important role in biological processes such as the immune response, inflammation regulation, and drug delivery. At the same time, the stem cell secretome can effectively mediate the process of tissue regeneration. This new theory has attributed the therapeutic effect of stem cells to their paracrine effects. The application of stem cells is not limited to exogenous stem cell transplantation. Endogenous stem cell homing and in situ regeneration strategies have received extensive attention. The application of stem cell derivatives, such as conditioned media, extracellular vesicles, and extracellular matrix, is an extension of stem cell paracrine theory. On the other hand, stem cell pretreatment strategies have also shown promising therapeutic effects. This article will systematically review the latest developments in these areas, summarize challenges in articular cartilage regeneration strategies involving stem cells, and describe prospects for future development.

Objective: To assess the results of stem cell applications in patients with peripheral arterial disease who could not undergo surgical treatment due to advanced-stage ischemia. Study design: Patients who could not undergo revascularization due to distal vascular insufficiency were recruited into this study between June 2009 and 2015. Stem cells obtained via bone marrow aspiration were utilized in 30 patients (17 male, 13 female; mean age, 56.2 y), and stem cells obtained from abdominal fat tissue were utilized in another 30 patients (22 male, 8 female; mean age, 58.9 y). Twenty patients with similar clinical symptoms who received medical treatment only comprised the control group for comparisons. Results: Stem cells were harvested from the bone marrow under local anesthesia, while general anesthesia was used for collecting stem cells of adipose tissue origin. Cells collected from each patient were processed in mobile units and were ready to use within approximately 1 hour. The harvested stem cells were administered percutaneously via intramuscular injections into the target tissues, conforming to vascular anatomy. Clinical status, ankle-brachial indices, pulse oximetry, and walking distance with exercise test were assessed at 1, 3, and 6 months after the procedures. Conclusion: Stem cell applications performed in patients unfeasible for revascularization appear to be associated with improvements in clinical symptoms, quality of life, and walking distance. We believe that this therapy may help reduce the rate of amputation