Introduction to stem cells and regenerative medicine

Stem Cell Therapy in Children with Traumatic Brain Injury

Pediatric traumatic brain injury is a cause of major mortality, and resultant neurological sequelae areassociated with long-term morbidity. Increasing studies have revealed stem cell therapy to be a potential new treatment. However, much work is still required to clarify the mechanism of action of effective stem cell therapy, type of stem cell therapy, optimal timing of therapy initiation, combination of cocurrent medical treatment and patient selection criteria. This paper will focus on stem cell therapy in children with traumatic brain injury.

Artificial Intelligence in Regenerative Medicine: Applications and Implications

The field of regenerative medicine is constantly advancing and aims to repair, regenerate, or substitute impaired or unhealthy tissues and organs using cutting-edge approaches such as stem cell-based therapies, gene therapy, and tissue engineering. Nevertheless, incorporating artificial intelligence (AI) technologies has opened new doors for research in this field. AI refers to the ability of machines to perform tasks that typically require human intelligence in ways such as learning the patterns in the data and applying that to the new data without being explicitly programmed. AI has the potential to improve and accelerate various aspects of regenerative medicine research and development, particularly, although not exclusively, when complex patterns are involved. This review paper provides an overview of AI in the context of regenerative medicine, discusses its potential applications with a focus on personalized medicine, and highlights the challenges and opportunities in this field.

Effects of Dopamine on stem cells and its potential roles in the treatment of inflammatory disorders: a narrative review

Inflammation is the host's protective response against harmful external stimulation that helps tissue repair and remodeling. However, excessive inflammation seriously threatens the patient's life. Due to anti-inflammatory effects, corticosteroids, immunosuppressants, and monoclonal antibodies are used to treat various inflammatory diseases, but drug resistance, non-responsiveness, and severe side effect limit their development and application. Therefore, developing other alternative therapies has become essential in anti-inflammatory therapy. In recent years, the in-depth study of stem cells has made them a promising alternative drug for the treatment of inflammatory diseases, and the function of stem cells is regulated by a variety of signals, of which dopamine signaling is one of the main influencing factors. In this review, we review the effects of dopamine on various adult stem cells (neural stem cells, mesenchymal stromal cells, hematopoietic stem cells, and cancer stem cells) and their signaling pathways, as well as the application of some critical dopamine receptor agonists/antagonists. Besides, we also review the role of various adult stem cells in inflammatory diseases and discuss the potential anti-inflammation function of dopamine receptors, which provides a new therapeutic target for regenerative medicine in inflammatory diseases.

Improved Method for Dental Pulp Stem Cell Preservation and Its Underlying Cell Biological Mechanism

Dental pulp stem cells (DPSCs) are considered a valuable cell source for regenerative medicine because of their high proliferative potential, multipotency, and availability. We established a new cryopreservation method (NCM) for collecting DPSCs, in which the tissue itself is cryopreserved and DPSCs are collected after thawing. We improved the NCM and developed a new method for collecting and preserving DPSCs more efficiently. Dental pulp tissue was collected from an extracted tooth, divided into two pieces, sandwiched from above and below using cell culture inserts, and cultured. As a result, the cells in the pulp tissue migrated vertically over time and localized near the upper and lower membranes over 2-3 days. With regard to the underlying molecular mechanism, SDF1 was predominantly involved in cell migration. This improved method is valuable and enables the more efficient collection and reliable preservation of DPSCs. It has the potential to procure a large number of DPSCs stably.

Knowledge Gaps in Generating Cell-Based Drug Delivery Systems and a Possible Meeting with Artificial Intelligence

Cell-based drug delivery systems are new strategies in targeted delivery in which cells or cell-membrane-derived systems are used as carriers and release their cargo in a controlled manner. Recently, great attention has been directed to cells as carrier systems for treating several diseases. There are various challenges in the development of cell-based drug delivery systems. The prediction of the properties of these platforms is a prerequisite step in their development to reduce undesirable effects. Integrating nanotechnology and artificial intelligence leads to more innovative technologies. Artificial intelligence quickly mines data and makes decisions more quickly and accurately. Machine learning as a subset of the broader artificial intelligence has been used in nanomedicine to design safer nanomaterials. Here, how challenges of developing cell-based drug delivery systems can be solved with potential predictive models of artificial intelligence and machine learning is portrayed. The most famous cell-based drug delivery systems and their challenges are described. Last but not least, artificial intelligence and most of its types used in nanomedicine are highlighted. The present Review has shown the challenges of developing cells or their derivatives as carriers and how they can be used with potential predictive models of artificial intelligence and machine learning.

Mesenchymal Stem Cell Therapy in Traumatic Spinal Cord Injury: A Systematic Review

Recovery from a traumatic spinal cord injury (TSCI) is challenging due to the limited regenerative capacity of the central nervous system to restore cells, myelin, and neural connections. Cell therapy, particularly with mesenchymal stem cells (MSCs), holds significant promise for TSCI treatment. This systematic review aims to analyze the efficacy, safety, and therapeutic potential of MSC-based cell therapies in TSCI. A comprehensive search of PUBMED and COCHRANE databases until February 2023 was conducted, combining terms such as "spinal cord injury," "stem cells," "stem cell therapy," "mesenchymal stem cells," and "traumatic spinal cord injury". Among the 53 studies initially identified, 22 (21 clinical trials and 1 case series) were included. Findings from these studies consistently demonstrate improvements in AIS (ASIA Impairment Scale) grades, sensory scores, and, to a lesser extent, motor scores. Meta-analyses further support these positive outcomes. MSC-based therapies have shown short- and medium-term safety, as indicated by the absence of significant adverse events within the studied timeframe. However, caution is required when drawing generalized recommendations due to the limited scientific evidence available. Further research is needed to elucidate the long-term safety and clinical implications of these advancements. Although significant progress has been made, particularly with MSC-based therapies, additional studies exploring other potential future therapies such as gene therapies, neurostimulation techniques, and tissue engineering approaches are essential for a comprehensive understanding of the evolving TSCI treatment landscape.

Intensive neurorehabilitation and allogeneic stem cells transplantation in canine degenerative myelopathy

Introduction

Degenerative myelopathy (DM) is a neurodegenerative spinal cord disease with upper motor neurons, with progressive and chronic clinical signs, similar to amyotrophic lateral sclerosis (ALS). DM has a complex etiology mainly associated with SOD1 gene mutation and its toxic role, with no specific treatment. Daily intensive rehabilitation showed survival time near 8 months but most animals are euthanized 6-12 months after clinical signs onset.

Methods

This prospective controlled blinded cohort clinical study aims to evaluate the neural regeneration response ability of DM dogs subjected to an intensive neurorehabilitation protocol with mesenchymal stem cells (MSCs) transplantation. In total, 13 non-ambulatory (OFS 6 or 8) dogs with homozygous genotype DM/DM and diagnosed by exclusion were included. All were allocated to the intensive neurorehabilitation with MSCs protocol (INSCP) group (n = 8) or to the ambulatory rehabilitation protocol (ARP) group (n = 5), which differ in regard to training intensity, modalities frequency, and MSCs transplantation. The INSCP group was hospitalized for 1 month (T0 to T1), followed by MSCs transplantation (T1) and a second month (T2), whereas the ARP group was under ambulatory treatment for the same 2 months.

Results

Survival mean time of total population was 375 days, with 438 days for the INSCP group and 274 for the ARP group, with a marked difference on the Kaplan-Meier survival analysis. When comparing the literature's results, there was also a clear difference in the one-sample t-test (p = 0.013) with an increase in time of approximately 70%. OFS classifications between groups at each time point were significantly different (p = 0.008) by the one-way ANOVA and the independent sample t-test.

Discussion

This INSCP showed to be safe, feasible, and a possibility for a long progression of DM dogs with quality of life and functional improvement. This study should be continued.

Regenerative potential of multinucleated cells: bone marrow adiponectin-positive multinucleated cells take the lead

BACKGROUND

Polyploid cells can be found in a wide evolutionary spectrum of organisms. These cells are assumed to be involved in tissue regeneration and resistance to stressors. Although the appearance of large multinucleated cells (LMCs) in long-term culture of bone marrow (BM) mesenchymal cells has been reported, the presence and characteristics of such cells in native BM and their putative role in BM reconstitution following injury have not been fully investigated.

METHODS

BM-derived LMCs were explored by time-lapse microscopy from the first hours post-isolation to assess their colony formation and plasticity. In addition, sub-lethally irradiated mice were killed every other day for four weeks to investigate the histopathological processes during BM regeneration. Moreover, LMCs from GFP transgenic mice were transplanted to BM-ablated recipients to evaluate their contribution to tissue reconstruction.

RESULTS

BM-isolated LMCs produced mononucleated cells with characteristics of mesenchymal stromal cells. Time-series inspections of BM sections following irradiation revealed that LMCs are highly resistant to injury and originate mononucleated cells which reconstitute the tissue. The regeneration process was synchronized with a transient augmentation of adipocytes suggesting their contribution to tissue repair. Additionally, LMCs were found to be adiponectin positive linking the observations on multinucleation and adipogenesis to BM regeneration. Notably, transplantation of LMCs to myeloablated recipients could reconstitute both the hematopoietic system and BM stroma.

CONCLUSIONS

A population of resistant multinucleated cells reside in the BM that serves as the common origin of stromal and hematopoietic lineages with a key role in tissue regeneration. Furthermore, this study underscores the contribution of adipocytes in BM reconstruction.

Fabrication of functional ameloblasts from hiPSCs for dental application

Tooth formation relies on two types of dental cell populations, namely, the dental epithelium and dental mesenchyme, and the interactions between these cell populations are important during tooth development. Although human-induced pluripotent stem cells (hiPSCs) can differentiate into dental epithelial and mesenchymal cells, organoid research on tooth development has not been established yet. This study focused on the hiPSC-derived human ameloblast organoid (hAO) using a three-dimensional (3D) culture system. hAOs had similar properties to ameloblasts, forming enamel in response to calcium and mineralization by interaction with the dental mesenchyme. hAOs simultaneously had osteogenic and odontogenic differentiation potential. Furthermore, hAOs demonstrated tooth regenerative potential upon interaction with the mouse dental mesenchyme. Our findings provide new insights into a suitable hiPSC-derived dental source and demonstrate that hAOs can be beneficial not only for tooth regeneration but also for the study of various dental diseases for which treatment has not been developed yet.

Regenerative capacity of trophoblast stem cell-derived extracellular vesicles on mesenchymal stem cells

BACKGROUND

Human mesenchymal stem cells (MSCs) are therapeutic for clinical applications because of their excellent immunomodulatory and multiple lineage differentiation abilities at tissue injury sites. However, insufficient number of cells and lack of regenerative properties during in vitro expansion still limit the clinical applicability of MSC therapies. Here, we demonstrated a preconditioning strategy with trophoblast stem cell-derived extracellular vesicles (TSC-EVs) to boost the proliferation and regenerative capacity of MSCs.

METHODS

We employed cell proliferation analyses such as CCK8 and BrdU assays to determine the proliferation-promoting role of TSC-EVs on MSCs. Osteogenic effects of TSC-EVs on MSCs were assessed by alkaline phosphatase (ALP) activity, calcium assays, and calvarial bone defect animal models. For skin regenerative effects, skin wound mice model was exploited to analyze wound-healing rate in this study, as well as immunofluorescence and histological staining evaluates. We also performed the small RNA profiling and RNA-sequencing analyzes to understand the cellular mechanism of TSC-EVs on MSCs.

RESULTS

TSC-EVs significantly promoted MSC proliferation under xeno-free conditions and facilitated the therapeutic effects of MSCs, including osteogenesis, anti-senescence, and wound healing. Transcriptomic analysis also provided evidence that specific microRNAs in TSC-EVs and differentially expressed genes (DEGs) in TSC-EV-treated MSCs showed the possibility of TSC-EVs triggering the regenerative abilities of MSCs with cytokine interaction. Hence, we found that NGF/Akt signaling mediated the regenerative effects of TSC-EVs on MSCs as a particular cellular signaling pathway.

CONCLUSION

The results of this study demonstrated the functional properties of TSC-EVs on MSCs for MSC-based therapeutic applications, suggesting that TSC-EVs may serve as a potential preconditioning source for MSC therapy in the clinical field of regenerative medicine.

Adipose-Derived Mesenchymal Stromal Cells: A Tool for Bone and Cartilage Repair

The osteogenic and chondrogenic differentiation ability of adipose-derived mesenchymal stromal cells (ASCs) and their potential therapeutic applications in bone and cartilage defects are reported in this review. This becomes particularly important when these disorders can only be poorly treated by conventional therapeutic approaches, and tissue engineering may represent a valuable alternative. Being of mesodermal origin, ASCs can be easily induced to differentiate into chondrocyte-like and osteocyte-like elements and used to repair damaged tissues. Moreover, they can be easily harvested and used for autologous implantation. A plethora of ASC-based strategies are being developed worldwide: they include the transplantation of freshly harvested cells, in vitro expanded cells or predifferentiated cells. Moreover, improving their positive effects, ASCs can be implanted in combination with several types of scaffolds that ensure the correct cell positioning; support cell viability, proliferation and migration; and may contribute to their osteogenic or chondrogenic differentiation. Examples of these strategies are described here, showing the enormous therapeutic potential of ASCs in this field. For safety and regulatory issues, most investigations are still at the experimental stage and carried out in vitro and in animal models. Clinical applications have, however, been reported with promising results and no serious adverse effects.

Stem cells as a therapeutic avenue for active and long-term complications of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a devastating neonatal intestinal disease associated with significant morbidity and mortality. Although decades of research have been dedicated to understanding the pathogenesis of NEC and developing therapies, it remains the leading cause of death among neonatal gastrointestinal diseases. Mesenchymal stem cells (MSCs) have garnered significant interest recently as potential therapeutic agents for the treatment of NEC. They have been shown to rescue intestinal injury and reduce the incidence and severity of NEC in various preclinical animal studies. MSCs and MSC-derived organoids and tissue engineered small intestine (TESI) have shown potential for the treatment of long-term sequela of NEC such as short bowel syndrome, neurodevelopmental delay, and chronic lung disease. Although the advances made in the use of MSCs are promising, further research is needed prior to the widespread use of these cells for the treatment of NEC.

MicroRNA26a Overexpression Hastens Osteoblast Differentiation Capacity in Dental Stem Cells

Dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHED) are a source of mesenchymal stem cells with the potential to differentiate into several cell types. We initially isolated SHED cells and compared their osteogenic capacity with commercially available DPSCs. Both cells exhibited similar capacities of growth and osteogenic differentiation. A fourfold to sixfold increase in endogenous microRNA26a (miR26a) expression during osteogenic differentiation of preosteoblasts and a similar but attenuated increase (twofold to fourfold) in differentiating SHED was observed, suggesting a role in the process. We, therefore, overexpressed miR26a in SHED to determine if the osteogenic differentiation capacity can be potentiated in vitro. SHED with a threefold increase in miR26a expression showed increased growth rate when compared with parent cells. When exposed to an osteogenic differentiating promoting medium, the miR26a overexpressing cells showed 100-fold increases in the expression of bone marker genes such as type 1 collagen, alkaline phosphatase, and Runx2. The mineralization capacity of these cells was also increased 15-fold. As miR26a targets regulate several bone-specific genes, we evaluated the effect of miR26a overexpression on established targets. We found a moderate decrease in SMAD1 and a profound decrease in PTEN expression. miR26a could potentiate its effect on osteoblast differentiation by its ability to inhibit PTEN and increase the viability of cells and their numbers, a process essential in osteoblast differentiation. Our studies suggest that the upregulation of miR26a can increase bone formation and may serve as an important target to further investigate its potential in tissue engineering applications.

Carbachol, along with calcium, indicates new strategy in neural differentiation of human adipose tissue-derived mesenchymal stem cells in vitro

INTRODUCTION

Over the past few years, stem cells have represented a promising treatment in neurological disorders due to the well-defined characteristics of their capability to proliferate and differentiate into any cell type, both in vitro and in vivo. Additionally, previous studies have shown that calcium signaling modulates the proliferation and differentiation of neural progenitor cells. The present study investigated the effect of carbachol (CCh), a cholinergic agonist activating acetylcholine receptors, with and without calcium, on the neural differentiation of human adipose tissue-derived mesenchymal stem cells (hADSCs) in neural media, including forskolin and 3-isobutyl-1-methyl-xanthine and retinoic acid.

METHODS

For this purpose, first, the MTT assay and acridine orange staining were studied to obtain the optimal concentration of CCh. Next, the differentiation tests, such as cellular calcium assay as well as evaluation of qualitative and quantitative expression of neuronal index markers through immunofluorescence staining and gene expression analysis, respectively, were performed on days 7 and 14 of the differentiation period.

RESULTS

According to the results, CCh at 1 μM concentration had no cytotoxicity on hADSCs and also induced cell proliferation. Furthermore, CCh with and without calcium increased the expression of neural-specific genes (NSE, MAP2, β-III-tubulin, and MAPK3) and proteins (γ-enolase, MAP2, and β-III-tubulin) as well as the amount of calcium in differentiated hADSCs at 7 and 14 days after induction.

CONCLUSIONS

In conclusion, the findings suggest that CCh acts as an influential therapeutic factor in the field of neural regenerative medicine and research.

The human neurosecretome: extracellular vesicles and particles (EVPs) of the brain for intercellular communication, therapy, and liquid-biopsy applications

Emerging evidence suggests that brain derived extracellular vesicles (EVs) and particles (EPs) can cross blood-brain barrier and mediate communication among neurons, astrocytes, microglial, and other cells of the central nervous system (CNS). Yet, a complete understanding of the molecular landscape and function of circulating EVs & EPs (EVPs) remain a major gap in knowledge. This is mainly due to the lack of technologies to isolate and separate all EVPs of heterogeneous dimensions and low buoyant density. In this review, we aim to provide a comprehensive understanding of the neurosecretome, including the extracellular vesicles that carry the molecular signature of the brain in both its microenvironment and the systemic circulation. We discuss the biogenesis of EVPs, their function, cell-to-cell communication, past and emerging isolation technologies, therapeutics, and liquid-biopsy applications. It is important to highlight that the landscape of EVPs is in a constant state of evolution; hence, we not only discuss the past literature and current landscape of the EVPs, but we also speculate as to how novel EVPs may contribute to the etiology of addiction, depression, psychiatric, neurodegenerative diseases, and aid in the real time monitoring of the "living brain". Overall, the neurosecretome is a concept we introduce here to embody the compendium of circulating particles of the brain for their function and disease pathogenesis. Finally, for the purpose of inclusion of all extracellular particles, we have used the term EVPs as defined by the International Society of Extracellular Vesicles (ISEV).

Stem Cell Therapy in Inflammatory Bowel Disease: A Review of Achievements and Challenges

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a group of chronic inflammatory diseases of the gastrointestinal tract. Repeated inflammation can lead to complications, such as intestinal fistula, obstruction, perforation, and bleeding. Unfortunately, achieving durable remission and mucosal healing (MH) with current treatments is difficult. Stem cells (SCs) have the potential to modulate immunity, suppress inflammation, and have anti-apoptotic and pro-angiogenic effects, making them an ideal therapeutic strategy to target chronic inflammation and intestinal damage in IBD. In recent years, hematopoietic stem cells (HSCs) and adult mesenchymal stem cells (MSCs) have shown efficacy in treating IBD. In addition, numerous clinical trials have evaluated the efficiency of MSCs in treating the disease. This review summarizes the current research progress on the safety and efficacy of SC-based therapy for IBD in both preclinical models and clinical trials. We discuss potential mechanisms of SC therapy, including tissue repair, paracrine effects, and the promotion of angiogenesis, immune regulation, and anti-inflammatory effects. We also summarize current SC engineering strategies aimed at enhancing the immunosuppressive and regenerative capabilities of SCs for treating intestinal diseases. Additionally, we highlight current limitations and future perspectives of SC-related therapy for IBD.

Cellular therapies in liver and pancreatic diseases

Over the past two decades, developments in regenerative medicine in gastroenterology have been greatly enhanced by the application of stem cells, which can self-replicate and differentiate into any somatic cell. The discovery of induced pluripotent stem cells has opened remarkable perspectives on tissue regeneration, including their use as a bridge to transplantation or as supportive therapy in patients with organ failure. The improvements in DNA manipulation and gene editing strategies have also allowed to clarify the physiopathology and to correct the phenotype of several monogenic diseases, both in vivo and in vitro. Further progress has been made with the development of three-dimensional cultures, known as organoids, which have demonstrated morphological and functional complexity comparable to that of a miniature organ. Hence, owing to its protean applications and potential benefits, cell and organoid transplantation has become a hot topic for the management of gastrointestinal diseases. In this review, we describe current knowledge on cell therapies in hepatology and pancreatology, providing insight into their future applications in regenerative medicine.

Direct cardiac reprogramming: A new technology for cardiac repair

Cardiovascular disease is one of the leading causes of morbidity and mortality worldwide, with myocardial infarctions being amongst the deadliest manifestations. Reduced blood flow to the heart can result in the death of cardiac tissue, leaving affected patients susceptible to further complications and recurrent disease. Further, contemporary management typically involves a pharmacopeia to manage the metabolic conditions contributing to atherosclerotic and hypertensive heart disease, rather than regeneration of the damaged myocardium. With modern healthcare extending lifespan, a larger demographic will be at risk for heart disease, driving the need for novel therapeutics that surpass those currently available in efficacy. Transdifferentiation and cellular reprogramming have been looked to as potential methods for the treatment of diseases throughout the body. Specifically targeting the fibrotic cells in cardiac scar tissue as a source to be reprogrammed into induced cardiomyocytes remains an appealing option. This review aims to highlight the history of and advances in cardiac reprogramming and describe its translational potential as a treatment for cardiovascular disease.

Review on kidney diseases: types, treatment and potential of stem cell therapy

Renal disorders are an emerging global public health issue with a higher growth rate despite progress in supportive therapies. In order to find more promising treatments to stimulate renal repair, stem cell-based technology has been proposed as a potentially therapeutic option. The self-renewal and proliferative nature of stem cells raised the hope to fight against various diseases. Similarly, it opens a new path for the treatment and repair of damaged renal cells. This review focuses on the types of renal diseases; acute and chronic kidney disease-their statistical data, and the conventional drugs used for treatment. It includes the possible stem cell therapy mechanisms involved and outcomes recorded so far, the limitations of using these regenerative medicines, and the progressive improvement in stem cell therapy by adopting approaches like PiggyBac, Sleeping Beauty, and the Sendai virus. Specifically, about the paracrine activities of amniotic fluid stem cells, renal stem cells, embryonic stem cells, mesenchymal stem cell, induced pluripotent stem cells as well as other stem cells.

Clinical application prospects and transformation value of dental follicle stem cells in oral and neurological diseases

Since dental pulp stem cells (DPSCs) were first reported, six types of dental SCs (DSCs) have been isolated and identified. DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation potential and neuro-ectodermal features. As a member of DSCs, dental follicle SCs (DFSCs) are the only cell type obtained at the early developing stage of the tooth prior to eruption. Dental follicle tissue has the distinct advantage of large tissue volume compared with other dental tissues, which is a prerequisite for obtaining a sufficient number of cells to meet the needs of clinical applications. Furthermore, DFSCs exhibit a significantly higher cell proliferation rate, higher colony-formation capacity, and more primitive and better anti-inflammatory effects than other DSCs. In this respect, DFSCs have the potential to be of great clinical significance and translational value in oral and neurological diseases, with natural advantages based on their origin. Lastly, cryopreservation preserves the biological properties of DFSCs and enables them to be used as off-shelf products for clinical applications. This review summarizes and comments on the properties, application potential, and clinical transformation value of DFSCs, thereby inspiring novel perspectives in the future treatment of oral and neurological diseases.

Mesenchymal Stem Cells for Treating Alzheimer's Disease: Cell Therapy and Chemical Reagent Pretreatment

As the size of the population aged 65 and older continues to grow, the incidence and mortality rates of Alzheimer's disease (AD) are increasing annually. Unfortunately, current treatments only treat symptoms temporarily and do not alter the patients' life expectancy or course of AD. Mesenchymal stem cells (MSCs) have shown a certain therapeutic potential in neurodegenerative diseases including AD due to their neuroinflammatory regulation and neuroprotective effects. However, the low survival and homing rates of MSCs after transplantation seriously affect their therapeutic effectiveness. Therefore, appropriate in vitro preconditioning is necessary to increase the survival and homing rates of MSCs to improve their effectiveness in treating AD. Here we summarize the therapeutic mechanisms of MSCs in AD and the chemical reagents used for the pretreatment of MSCs.

Engineering cells for precision drug delivery: New advances, clinical translation, and emerging strategies

Cells have emerged as a promising new form of drug delivery carriers owing to their distinguished advantages such as naturally bypassing immune recognition, intrinsic capability to navigate biological barriers, and access to hard-to-reach tissues via onboarding sensing and active motility. Over the past two decades, a large body of work has focused on understanding the ability of cell carriers to breach biological barriers and to modulate drug pharmacokinetics and pharmacodynamics. These efforts have led to the engineering of various cells for tissue-specific drug delivery. Despite exciting advances, clinical translation of cell-based drug carriers demands a thorough understanding of the pressing challenges and potential strategies to overcome them. Here, we summarize recent advances and new concepts in cell-based drug carriers and their clinical translation. We also discuss key considerations and emerging strategies to engineering the next-generation cell-based delivery technologies for more precise, targeted drug delivery.

Recent Advances in Apical Periodontitis Treatment: A Narrative Review

Apical periodontitis is an inflammatory response caused by pulp infection. It induces bone resorption in the apical and periapical regions of the tooth. The most conservative approach to treat this condition is nonsurgical endodontic treatment. However, clinical failure has been reported with this approach; thus, alternative procedures are required. This review highlights recent literature regarding advanced approaches for the treatment of apical periodontitis. Various therapies, including biological medications, antioxidants, specialized pro-resolving lipid mediators, and stem cell therapy, have been tested to increase the success rate of treatment for apical periodontitis. Some of these approaches remain in the in vivo phase of research, while others have just entered the translational research phase to validate clinical application. However, a detailed understanding of the molecular mechanisms that occur during development of the immunoinflammatory reaction in apical periodontitis remains unclear. The aim of this review was to summarize advanced approaches for the treatment of apical periodontitis. Further research can confirm the potential of these alternative nonsurgical endodontic treatment approaches.

Stem cells in the treatment of Alzheimer's disease - Promises and pitfalls

Alzheimer's disease (AD) is the most widespread form of neurodegenerative disorder that causes memory loss and multiple cognitive issues. The underlying mechanisms of AD include the build-up of amyloid-β and phosphorylated tau, synaptic damage, elevated levels of microglia and astrocytes, abnormal microRNAs, mitochondrial dysfunction, hormonal imbalance, and age-related neuronal loss. However, the etiology of AD is complex and involves a multitude of environmental and genetic factors. Currently, available AD medications only alleviate symptoms and do not provide a permanent cure. Therefore, there is a need for therapies that can prevent or reverse cognitive decline, brain tissue loss, and neural instability. Stem cell therapy is a promising treatment for AD because stem cells possess the unique ability to differentiate into any type of cell and maintain their self-renewal. This article provides an overview of the pathophysiology of AD and existing pharmacological treatments. This review article focuses on the role of various types of stem cells in neuroregeneration, the potential challenges, and the future of stem cell-based therapies for AD, including nano delivery and gaps in stem cell technology.

Regenerative Potential of Human Breast Milk: A Natural Reservoir of Nutrients, Bioactive Components and Stem cells

Human milk is a complex fluid that contains carbohydrates, lipids, proteins, and other bioactive molecules (immunoglobulins, lactoferrin, human milk oligosaccharides, lysozyme, leukocytes, cytokines, hormones, and microbiome) which provide nutritional, immunological, and developmental benefits to the infant. In addition to their involvement in the development, these bioactive compounds have a key role in anti-oncogenicity, neuro-cognitive development, cellular communication, and differentiation. As a result of technological advancements, it has been discovered that human breast milk contains cells that display many of the characteristics of stem cells with multilineage differentiation potentials. Do these cells have any specific properties or roles? Research efforts on breast milk cells have been mainly focused on leukocytes based on their immunological perspective in the early postpartum period. This review summarizes the nutritional components in human milk, i.e., the macro and micronutrients required for the growth and development of infants. Further, it discusses the research work reported concerning the purification, propagation, and differentiation of breast milk progenitor cells and highlights the advancements made in this newly emerging field of stem cell biology and regenerative medicine.

Validation of long-term handling and storage conditions for hematopoietic stem cell products for autologous transplants

Hematopoietic stem cells (HPSCs) are multipotent stem cells that can differentiate into lymphoid and myeloid progenitors, giving rise to white blood cells (WBCs), red blood cells (RBCs), and platelets. HPSCs are a widely used treatment for many hematological non-malignant and malignant disorders. HPSCs can be used in the fresh or cryopreserved state for future use. Fresh HPSCs are typically stored at 2-6°C for up to 72 hours and are primarily used for allogeneic transplants or autologous transplants in myeloma and lymphoma patients. However, in some cases of autologous donations, HPSC transplantation is delayed more than three days after collection. In such situations, the cells are thawed after short-term preservation, resulting in a 35% cell viability loss. This study aimed to investigate the quality of HPSCs products after long-term storage exceeding 72 hours. The quality of HPSCs products was assessed by measuring viable CD34+ cell count, the total number of nucleated cells (TNC), and HPSCs recovery after different storage intervals of up to 120 hours in hypothermal storage. The mean total cell viability decreased by 2.18% within 72 hours and 7.4% within 120 hours, while mean CD34+ cell recovery was 92.61 % at 72 hours and 83.83 % at 120 hours in hypothermal storage. The mean TNC recovery was 89.93% at 72 hours and 76.18 % at 120 hours. All products were free from bacterial contamination for up to 120 hours under hypothermal storage conditions.

Stem cell derived therapies to preserve and repair the developing intestine

Stem cell research and the use of stem cells in therapy have seen tremendous growth in the last two decades. Neonatal intestinal disorders such as necrotizing enterocolitis, Hirschsprung disease, and gastroschisis have high morbidity and mortality and limited treatment options with varying success rates. Stem cells have been used in several pre-clinical studies to address various neonatal disorders with promising results. Stem cell and patient population selection, timing of therapy, as well as safety and quality control are some of the challenges that must be addressed prior to the widespread clinical application of stem cells. Further research and technological advances such as the use of cell delivery technology can address these challenges and allow for continued progress towards clinical translation.

Stem Cell Therapies for Epidermolysis Bullosa Treatment

Epidermolysis bullosa (EB) includes a group of rare skin diseases characterized by skin fragility with bullous formation in the skin, in response to minor mechanical injury, as well as varying degrees of involvement of the mucous membranes of the internal organs. EB is classified into simplex, junctional, dystrophic and mixed. The impact of the disease on patients is both physical and psychological, with the result that their quality of life is constantly affected. Unfortunately, there are still no approved treatments available to confront the disease, and treatment focuses on improving the symptoms with topical treatments to avoid complications and other infections. Stem cells are undifferentiated cells capable of producing, maintaining and replacing terminally differentiated cells and tissues. Stem cells can be isolated from embryonic or adult tissues, including skin, but are also produced by genetic reprogramming of differentiated cells. Preclinical and clinical research has recently greatly improved stem cell therapy, making it a promising treatment option for various diseases in which current medical treatments fail to cure, prevent progression, or alleviate symptoms. So far, stem cells from different sources, mainly hematopoietic and mesenchymal, autologous or heterologous have been used for the treatment of the most severe forms of the disease each one of them with some beneficial effects. However, the mechanisms through which stem cells exert their beneficial role are still unknown or incompletely understood and most importantly further research is required to evaluate the effectiveness and safety of these treatments. The transplantation of skin grafts to patients produced by gene-corrected autologous epidermal stem cells has been proved to be rather successful for the treatment of skin lesions in the long term in a limited number of patients. Nevertheless, these treatments do not address the internal epithelia-related complications manifested in patients with more severe forms.

Clinical trials using dental stem cells: 2022 update

For nearly 20 years, dental stem cells (DSCs) have been successfully isolated from mature/immature teeth and surrounding tissue, including dental pulp of permanent teeth and exfoliated deciduous teeth, periodontal ligaments, dental follicles, and gingival and apical papilla. They have several properties (such as self-renewal, multidirectional differentiation, and immunomodulation) and exhibit enormous potential for clinical applications. To date, many clinical articles and clinical trials using DSCs have reported the treatment of pulpitis, periapical lesions, periodontitis, cleft lip and palate, acute ischemic stroke, and so on, and DSC-based therapies obtained satisfactory effects in most clinical trials. In these studies, no adverse events were reported, which suggested the safety of DSC-based therapy. In this review, we outline the characteristics of DSCs and summarize clinical trials and their safety as DSC-based therapies. Meanwhile, we also present the current limitations and perspectives of DSC-based therapy (such as harvesting DSCs from inflamed tissue, applying DSC-conditioned medium/DSC-derived extracellular vesicles, and expanding-free strategies) to provide a theoretical basis for their clinical applications.

Application of a Magnetic Platform in α6 Integrin-Positive iPSC-TM Purification

The emergence of induced pluripotent stem cell (iPSC) technology has provided a new approach to regenerating decellularized trabecular meshwork (TM) in glaucoma. We have previously generated iPSC-derived TM (iPSC-TM) using a medium conditioned by TM cells and verified its function in tissue regeneration. Because of the heterogeneity of iPSCs and the isolated TM cells, iPSC-TM cells appear to be heterogeneous, which impedes our understanding of how the decellularized TM may be regenerated. Herein, we developed a protocol based on a magnetic-activated cell sorting (MACS) system or an immunopanning (IP) method for sorting integrin subunit alpha 6 (ITGA6)-positive iPSC-TM, an example of the iPSC-TM subpopulation. We first analyzed the purification efficiency of these two approaches by flow cytometry. In addition, we also determined cell viability by analyzing the morphologies of the purified cells. To conclude, the MACS-based purification could yield a higher ratio of ITGA6-positive iPSC-TM and maintain a relatively higher cell viability than the IP-based method, allowing for the preparation of any iPSC-TM subpopulation of interest and facilitating a better understanding of the regenerative mechanism of iPSC-based therapy.

Response of mesenchymal stem cells to surface topography of scaffolds and the underlying mechanisms

Mesenchymal stem/stromal cells (MSCs) serve as essential components of regenerative medicine. Their destiny is influenced by the interaction of the cells with the external environment. In addition to the biochemical cues in a microenvironment, physical cues of the topography of the surrounding materials such as the extracellular matrix emerge as a crucial regulator of stem cell destiny and function. With recent advances in technologies of materials production and surface modification, surfaces with micro/nanotopographical characteristics can be fabricated to mimic the micro/nanoscale mechanical stimuli of the extracellular matrix environment and regulate the biological behavior of cells. Understanding the interaction of cells with the topography of a surface is conducive to the control of stem cell fate for application in regenerative medicine. However, the mechanisms by which topography affects the biological behavior of stem cells have not been fully elucidated. This review will present the effects of surface topography at the nano/micrometer scale on stem cell adhesion, morphology, proliferation, migration, and differentiation. It also focuses on discussing current theories about the sensing and recognition of surface topology cues, the transduction of the extracellular cues into plasma, and the final activation of related signaling pathways and downstream gene expression in MSCs. These insights will provide a theoretical basis for the future design of biomaterial scaffolds for application in regenerative medicine and tissue engineering.

A Simplified and Effective Approach for the Isolation of Small Pluripotent Stem Cells Derived from Human Peripheral Blood

Pluripotent stem cells are key players in regenerative medicine. Embryonic pluripotent stem cells, despite their significant advantages, are associated with limitations such as their inadequate availability and the ethical dilemmas in their isolation and clinical use. The discovery of very small embryonic-like (VSEL) stem cells addressed the aforementioned limitations, but their isolation technique remains a challenge due to their small cell size and their efficiency in isolation. Here, we report a simplified and effective approach for the isolation of small pluripotent stem cells derived from human peripheral blood. Our approach results in a high yield of small blood stem cell (SBSC) population, which expresses pluripotent embryonic markers (e.g., Nanog, SSEA-3) and the Yamanaka factors. Further, a fraction of SBSCs also co-express hematopoietic markers (e.g., CD45 and CD90) and/or mesenchymal markers (e.g., CD29, CD105 and PTH1R), suggesting a mixed stem cell population. Finally, quantitative proteomic profiling reveals that SBSCs contain various stem cell markers (CD9, ITGA6, MAPK1, MTHFD1, STAT3, HSPB1, HSPA4), and Transcription reg complex factors (e.g., STAT5B, PDLIM1, ANXA2, ATF6, CAMK1). In conclusion, we present a novel, simplified and effective isolating process that yields an abundant population of small-sized cells with characteristics of pluripotency from human peripheral blood.

Plausible Role of Stem Cell Types for Treating and Understanding the Pathophysiology of Depression

Major Depressive Disorder (MDD), colloquially known as depression, is a debilitating condition affecting an estimated 3.8% of the population globally, of which 5.0% are adults and 5.7% are above the age of 60. MDD is differentiated from common mood changes and short-lived emotional responses due to subtle alterations in gray and white matter, including the frontal lobe, hippocampus, temporal lobe, thalamus, striatum, and amygdala. It can be detrimental to a person’s overall health if it occurs with moderate or severe intensity. It can render a person suffering terribly to perform inadequately in their personal, professional, and social lives. Depression, at its peak, can lead to suicidal thoughts and ideation. Antidepressants manage clinical depression and function by modulating the serotonin, norepinephrine, and dopamine neurotransmitter levels in the brain. Patients with MDD positively respond to antidepressants, but 10–30% do not recuperate or have a partial response accompanied by poor life quality, suicidal ideation, self-injurious behavior, and an increased relapse rate. Recent research shows that mesenchymal stem cells and iPSCs may be responsible for lowering depression by producing more neurons with increased cortical connections. This narrative review discusses the plausible functions of various stem cell types in treating and understanding depression pathophysiology.

Recent Advances in Nano-Drug Delivery Systems for the Treatment of Diabetic Wound Healing

Diabetes mellitus (DM) induced wound healing impairment remains a serious health problem and burden on the clinical obligation for high amputation rates. Based on the features of wound microenvironment, biomaterials loading specific drugs can benefit diabetic wound treatment. Drug delivery systems (DDSs) can carry diverse functional substances to the wound site. Nano-drug delivery systems (NDDSs), benefiting from their features related to nano size, overcome limitations of conventional DDSs application and are considered as a developing process in the wound treatment field. Recently, a number of finely designed nanocarriers efficiently loading various substances (bioactive and non-bioactive factors) have emerged to circumvent constraints faced by traditional DDSs. This review describes various recent advances of nano-drug delivery systems involved in mitigating diabetes mellitus-based non-healing wounds.

The Wisdom in Teeth: Neuronal Differentiation of Dental Pulp Cells

Mesenchymal stem/stromal cells (MSCs) are found in almost all postnatal organs. Under appropriate environmental cues, multipotency enables MSCs to serve as progenitors for several lineage-specific, differentiated cell types. In vitro expansion and differentiation of MSCs give the opportunity to obtain hardly available somatic cells, such as neurons. The neurogenic potential of MSCs makes them a promising, autologous source to restore damaged tissue and as such, they have received much attention in the field of regenerative medicine. Several stem cell pool candidates have been studied thus far, but only a few of them showed neurogenic differentiation potential. Due to their embryonic ontology, stem cells residing in the stroma of the dental pulp chamber are an exciting source for in vitro neural cell differentiation. In this study, we review the key properties of dental pulp stem cells (DPSCs), with a particular focus on their neurogenic potential. Moreover, we summarize the various presently available methods used for neural differentiation of human DPSCs also emphasizing the difficulties in reproducibly high production of such cells. We postulate that because DPSCs are stem cells with very close ontology to neurogenic lineages, they may serve as excellent targets for neuronal differentiation in vitro and even for direct reprogramming.

The Therapeutic Application of Stem Cells and Their Derived Exosomes in the Treatment of Radiation-Induced Skin Injury

Radiation-induced skin injury (RISI) is a serious concern for nuclear accidents and cancer radiotherapy, which seriously affects the quality of life of patients. This injury differs from traditional wounds due to impaired healing and the propensity to recurrence and is divided into acute and chronic phases on the basis of the injury time. Unfortunately, there are few effective therapies for preventing or mitigating this injury. Over the last few decades, various studies have focused on the effects of stem cell-based therapies to address the tissue repair and regeneration of irradiated skin. These stem cells modulate inflammation and instigate tissue repair by differentiating into specific kinds of cells or releasing paracrine factors. Stem cell-based therapies, including bone marrow-derived stem cells (BMSCs), adipose-derived stem cells (ADSCs) and stromal vascular fraction (SVF), have been reported to facilitate wound healing after radiation exposure. Moreover, stem cell-derived exosomes have recently been suggested as an effective and cell-free approach to support skin regeneration, circumventing the concerns respecting direct application of stem cells. Based on the literature on stem cell-based therapies for radiation-induced skin injury, we summarize the characteristics of different stem cells and describe their latest animal and clinical applications, as well as potential mechanisms. The promise of stem-cell based therapies against radiation-induced skin injury contribute to our response to nuclear events and smooth progress of cancer radiotherapy.

Cell-Based Drug Delivery Systems with Innate Homing Capability as a Novel Nanocarrier Platform

Nanoparticle-based drug delivery systems have been designed to treat various diseases. However, many problems remain, such as inadequate tumor targeting and poor therapeutic outcomes. To overcome these obstacles, cell-based drug delivery systems have been developed. Candidates for cell-mediated drug delivery include blood cells, immune cells, and stem cells with innate tumor tropism and low immunogenicity; they act as a disguise to deliver the therapeutic payload. In drug delivery systems, therapeutic agents are encapsulated intracellularly or attached to the surface of the plasma membrane and transported to the desired site. Here, we review the pros and cons of cell-based therapies and discuss their homing mechanisms in the tumor microenvironment. In addition, different strategies to load therapeutic agents inside or on the surface of circulating cells and the current applications for a wide range of disease treatments are summarized.

Whole transcriptomic analysis of mesenchymal stem cells cultured in Nichoid micro-scaffolds

Mesenchymal stem cells (MSCs) are known to be ideal candidates for clinical applications where not only regenerative potential but also immunomodulation ability is fundamental. Over the last years, increasing efforts have been put into the design and fabrication of 3D synthetic niches, conceived to emulate the native tissue microenvironment and aiming at efficiently controlling the MSC phenotype in vitro. In this panorama, our group patented an engineered microstructured scaffold, called Nichoid. It is fabricated through two-photon polymerization, a technique enabling the creation of 3D structures with control of scaffold geometry at the cell level and spatial resolution beyond the diffraction limit, down to 100 nm. The Nichoid's capacity to maintain higher levels of stemness as compared to 2D substrates, with no need for adding exogenous soluble factors, has already been demonstrated in MSCs, neural precursors, and murine embryonic stem cells. In this work, we evaluated how three-dimensionality can influence the whole gene expression profile in rat MSCs. Our results show that at only 4 days from cell seeding, gene activation is affected in a significant way, since 654 genes appear to be differentially expressed (392 upregulated and 262 downregulated) between cells cultured in 3D Nichoids and in 2D controls. The functional enrichment analysis shows that differentially expressed genes are mainly enriched in pathways related to the actin cytoskeleton, extracellular matrix (ECM), and, in particular, cell adhesion molecules (CAMs), thus confirming the important role of cell morphology and adhesions in determining the MSC phenotype. In conclusion, our results suggest that the Nichoid, thanks to its exclusive architecture and 3D cell adhesion properties, is not only a useful tool for governing cell stemness but could also be a means for controlling immune-related MSC features specifically involved in cell migration.

Chronic Kidney Disease: Challenges in Translational Medicine

Chronic kidney disease (CKD) has long been recognized as a state of progressive decline in renal function. Morbidity and mortality are well correlated to the stage of renal function decline. Approximately one million deaths are estimated to be related to CKD worldwide. They are mostly associated with cardiovascular disease as a result of concurrent hypertension, accelerated atherosclerosis, and volume overload. Even with the best current treatment, disease progression is the general rule with a small fraction who reach CKD stage 5 requiring kidney transplantation or dialysis. Transplant patients show substantial reductions in mortality and cardiovascular events, as well as improvements in quality of life. However, the capacity of health systems to deliver kidney transplantation varies worldwide with worse indicators in low-income countries. Consequently, exploring novel and better therapeutic options for CKD is mandatory. Cell-based therapy is a promising strategy for treating CKD in preclinical models, and several clinical trials involving kidney disease exhibit a favorable safety profile. This chapter aims to provide an overview of CKD and the recent results of clinical trials of cell therapy in kidney diseases.

Organ Regeneration Through Stem Cells and Tissue Engineering

Loss of organ and tissue due to injuries or diseases led to the development of regenerative therapies to decrease reliance on organ transplantations. It deals with employing the self-renewal ability of stem cells to differentiate into numerous lineages to assist in providing effective treatment for a range of various injuries and diseases. Regenerative engineering of organs or tissues represents an ever-expanding field that is aimed at developing biological replacements for dysfunctional organs or injured tissues. The critical issue, however, with the engineering of organs outside the human body is the insufficient availability of human cells, the absence of a suitable matrix with the same architecture and composition as the target tissue, and the maintenance of organ viability in the absence of the blood supply. The issue regarding the maintenance of the engineered organ viability can be solved using bioreactors consisting of mediums with defined chemical composition, i.e., nutrients, cofactors, and growth factors that can successively sustain the target cell's viability. Engineered extracellular matrices and stem cells to regenerate organs outside the human body are also being used. Clinically, various adult stem cell therapies are readily under practice. This review will focus on the regeneration of organs through various types of stem cells and tissue engineering techniques.

Stem Cells: Recent Developments Redefining Epilepsy Therapy

The field of stem cell therapy is growing rapidly and hopes to offer an alternative solution to diseases that are historically treated medically or surgically. One such focus of research is the treatment of medically refractory epilepsy, which is traditionally approached from a surgical or interventional standpoint. Research shows that stem cell transplantation has potential to offer significant benefits to the epilepsy patient by reducing seizure frequency, intensity, and neurological deficits that often result from the condition. This review explores the basic science progress made on the topic of stem cells and epilepsy by focusing on experiments using animal models and highlighting the most recent developments from the last 4 years.

Evaluation of the Optimal Manufacturing Protocols and Therapeutic Properties of Mesenchymal Stem/Stromal Cells Derived from Wharton's Jelly

Wharton's jelly (WJ) from the umbilical cord (UC) is a good source of mesenchymal stem/stromal cells (MSCs), which can be isolated and used in therapy. Current knowledge shows that even small changes in the cell environment may result in obtaining a subpopulation of cells with different therapeutic properties. For this reason, the conditions of UC transportation, cell isolation, and cultivation and the banking of cells destined for clinical use should be unified and optimized. In this project, we tried various protocols for cell vs. bioptat isolation, banking, and transport in order to determine the most optimal. The most efficient isolation method of WJ-MSCs was chopping the whole umbilical matrix with a scalpel after vessel and lining membrane removal. The optimal solution for short term cell transportation was a multi-electrolyte fluid without glucose. Considering the use of WJ-MSCs in cell therapies, it was important to investigate the soluble secretome of both WJ bioptats and WJ-MSCs. WJ-MSCs secreted higher levels of cytokines and chemokines than WJ bioptats. WJ-MSCs secreted HGF, CCL2, ICAM-1, BDNF, and VEGF. Since these cells might be used in treating neurodegenerative disorders, we investigated the impact of cerebrospinal fluid (CSF) on WJ-MSCs' features. In the presence of CSF, the cells expressed consecutive neural markers both at the protein and gene level: nestin, β-III-tubulin, S-100-β, GFAP, and doublecortin. Based on the obtained results, a protocol for manufacturing an advanced-therapy medicinal product was composed.

The Emerging Role of Menstrual-Blood-Derived Stem Cells in Endometriosis

The human endometrium has a complex cellular composition that is capable of promoting cyclic regeneration, where endometrial stem cells play a critical role. Menstrual blood-derived stem cells (MenSC) were first discovered in 2007 and described as exhibiting mesenchymal stem cell properties, setting them in the spotlight for endometriosis research. The stem cell theory for endometriosis pathogenesis, supported by the consensual mechanism of retrograde menstruation, highlights the recognized importance that MenSC have gained by potentially being directly related to the genesis, development and maintenance of ectopic endometriotic lesions. Meanwhile, the differences observed between MenSC in patients with endometriosis and in healthy women underlines the applicability of these cells as a putative biomarker for the early diagnosis of endometriosis, as well as for the development of targeted therapies. It is expected that in the near future MenSC will have the potential to change the way we manage this complex disease, once their long-term safety and effectiveness are assessed.

Future stem cell analysis: progress and challenges towards state-of-the art approaches in automated cells analysis

Background and Aims

A microscopic image has been used in cell analysis for cell type identification and classification, cell counting and cell size measurement. Most previous research works are tedious, including detailed understanding and time-consuming. The scientists and researchers are seeking modern and automatic cell analysis approaches in line with the current in-demand technology.

Objectives

This article provides a brief overview of a general cell and specific stem cell analysis approaches from the history of cell discovery up to the state-of-the-art approaches.

Methodology

A content description of the literature study has been surveyed from specific manuscript databases using three review methods: manuscript identification, screening, and inclusion. This review methodology is based on Prism guidelines in searching for originality and novelty in studies concerning cell analysis.

Results

By analysing generic cell and specific stem cell analysis approaches, current technology offers tremendous potential in assisting medical experts in performing cell analysis using a method that is less laborious, cost-effective, and reduces error rates.

Conclusion

This review uncovers potential research gaps concerning generic cell and specific stem cell analysis. Thus, it could be a reference for developing automated cells analysis approaches using current technology such as artificial intelligence and deep learning.

The Pivotal Role of Stem Cells in Veterinary Regenerative Medicine and Tissue Engineering

The introduction of new regenerative therapeutic modalities in the veterinary practice has recently picked up a lot of interest. Stem cells are undifferentiated cells with a high capacity to self-renew and develop into tissue cells with specific roles. Hence, they are an effective therapeutic option to ameliorate the ability of the body to repair and engineer damaged tissues. Currently, based on their facile isolation and culture procedures and the absence of ethical concerns with their use, mesenchymal stem cells (MSCs) are the most promising stem cell type for therapeutic applications. They are becoming more and more well-known in veterinary medicine because of their exceptional immunomodulatory capabilities. However, their implementation on the clinical scale is still challenging. These limitations to their use in diverse affections in different animals drive the advancement of these therapies. In the present article, we discuss the ability of MSCs as a potent therapeutic modality for the engineering of different animals' tissues including the heart, skin, digestive system (mouth, teeth, gastrointestinal tract, and liver), musculoskeletal system (tendons, ligaments, joints, muscles, and nerves), kidneys, respiratory system, and eyes based on the existing knowledge. Moreover, we highlighted the promises of the implementation of MSCs in clinical use in veterinary practice.

Optical Tissue Clearing to Study the Intra-Pulmonary Biodistribution of Intravenously Delivered Mesenchymal Stromal Cells and Their Interactions with Host Lung Cells

Mesenchymal stromal cells (MSCs) injected intravenously are trapped in the capillaries of the lungs and die within the first 24 h. Studying the biodistribution and fate of labelled therapeutic cells in the 3D pulmonary context is important to understand their function in this organ and gain insights into their mechanisms of action. Optical tissue clearing enables volumetric cell tracking at single-cell resolution. Thus, we compared three optical tissue-clearing protocols (Clear, Unobstructed Brain/Body Imaging Cocktails and Computational analysis (CUBIC), modified stabilised 3D imaging of solvent-cleared organs (s-DISCO) and ethyl cinnamate (ECi)) to evaluate their potential to track the biodistribution of human umbilical cord MSCs expressing the tdTomato fluorescence reporter and investigate how they interact with host cells in the mouse lung. The results showed that although CUBIC clearing is the only method that enables direct imaging of fluorescently labelled MSCs, combining s-DISCO or ECi with immunofluorescence or dye labelling allows the interaction of MSCs with endothelial and immune cells to be studied. Overall, this comparative study offers guidance on selecting an optical tissue-clearing method for cell tracking applications.

Preparation and Use of Decellularized Extracellular Matrix for Tissue Engineering

The multidisciplinary fields of tissue engineering and regenerative medicine have the potential to revolutionize the practise of medicine through the abilities to repair, regenerate, or replace tissues and organs with functional engineered constructs. To this end, tissue engineering combines scaffolding materials with cells and biologically active molecules into constructs with the appropriate structures and properties for tissue/organ regeneration, where scaffolding materials and biomolecules are the keys to mimic the native extracellular matrix (ECM). For this, one emerging way is to decellularize the native ECM into the materials suitable for, directly or in combination with other materials, creating functional constructs. Over the past decade, decellularized ECM (or dECM) has greatly facilitated the advance of tissue engineering and regenerative medicine, while being challenged in many ways. This article reviews the recent development of dECM for tissue engineering and regenerative medicine, with a focus on the preparation of dECM along with its influence on cell culture, the modification of dECM for use as a scaffolding material, and the novel techniques and emerging trends in processing dECM into functional constructs. We highlight the success of dECM and constructs in the in vitro, in vivo, and clinical applications and further identify the key issues and challenges involved, along with a discussion of future research directions.