Clinical trials for stem cell therapies

Emerging technologies for quality control of cell-based, advanced therapy medicinal products

Advanced therapy medicinal products (ATMP) are complex medicines based on gene therapy, somatic cell therapy, and tissue engineering. These products are rapidly arising as novel and promising therapies for a wide range of different clinical applications. The process for the development of well-established ATMPs is challenging. Many issues must be considered from raw material, manufacturing, safety, and pricing to assure the quality of ATMPs and their implementation as innovative therapeutic tools. Among ATMPs, cell-based ATMPs are drugs altogether. As for standard drugs, technologies for quality control, and non-invasive isolation and production of cell-based ATMPs are then needed to ensure their rapidly expanding applications and ameliorate safety and standardization of cell production. In this review, emerging approaches and technologies for quality control of innovative cell-based ATMPs are described. Among new techniques, microfluid-based systems show advantages related to their miniaturization, easy implementation in analytical process and automation which allow for the standardization of the final product.

Multichannel-optical imaging for in vivo evaluating the safety and therapeutic efficacy of stem cells in tumor model in terms of cell tropism, proliferation and NF-κB activity

Stem cell-based cancer treatment has garnered significant attention, yet its safety and efficacy remain incompletely understood. The nuclear factor-kappa B (NF-κB) pathway, a critical signaling mechanism involved in tumor growth, angiogenesis, and invasion, serves as an essential metric for evaluating the behavior of stem cells in tumor models. Herein, we report the development of a triple-channel imaging system capable of simultaneously monitoring the tropism of stem cells towards tumors, assessing tumor proliferation, and quantifying tumor NF-κB activity. In this system, we generated a CRISPR-Cas9 gene-edited human glioblastoma cell line, GE-U87-MG, which provided a reliable readout of the proliferation and NF-κB activity of tumors by EF1α-RFLuc- and NF-κB-GLuc-based bioluminescent imaging, respectively. Additionally, near infrared-II emitting Tat-PEG-AgAuSe quantum dots were developed for tracking of stem cell tropism towards tumor. In a representative case involving human mesenchymal stem cells (hMSCs), multichannel imaging revealed no discernible effect of hMSCs on the proliferation and NF-κB activity of GE-U87-MG tumors. Moreover, hMSCs engineered to overexpress the necrosis factor-related apoptosis-inducing ligand were able to inhibit NF-κB activity and growth of GE-U87-MG in vivo. Taken together, our imaging system represents a powerful and feasible approach to evaluating the safety and therapeutic efficacy of stem cells in tumor models.

Bio-distribution and toxicity potential of human umbilical cord mesenchymal stem cells in cynomolgus monkeys

Mesenchymal stem cells (MSCs) have demonstrated promising advantages in the therapies of many diseases, while its multi-directional differentiation potential and immunotoxicity are the major concerns hindered their clinical translation. In this study, human umbilical Mesenchymal stem cell (hUC-MSCs) were labeled with a near-infrared fluorescent dye DiR before infused into cynomolgus monkeys, and the amount of hUC-MSCs in the peripheral blood were dynamically estimated from 5 min to 28 days post a single administration at 3 × 106 cells/kg and 2 × 107 cells/kg intravenously. As results, some hUC-MSCs distributed to the whole body within 5 min, while most of the cells accumulate in the lungs along with the systemic blood circulation, and subsequently released into the blood. The toxicity potentials of hUC-MSCs were investigated in another 30 cynomolgus monkeys, and the cells were repeatedly administrated at doses of 3 × 106 cells/kg and 2 × 107 cells/kg for 5 times on a weekly basis, with a recovery period of 1 months. hUC-MSCs showed no obvious toxic effects in cynomolgus monkeys, except xenogeneic immune rejection to human stem cells. Low levels of the hUC-MSC gene were detected in the peripheral blood of a few animals administered 2 × 107 cells/kg at 30 min subsequent to the first and last administration, and there was no significant difference in the copy number of the hUC-MSC gene in the blood samples compared with the first and last administration, indicating that the hUC-MSC was not significantly amplified in vivo, and it its safe in non-human primates. Our study for the first time verified the safety of long-term use of hUC-MSCs in primates. We have pioneered a technology for the real-time detection of hUC-MSCs in peripheral blood and provide dynamicand rapid monitoring of the distribution characteristics of hUC-MSCs in vivo. Here, we provide data supporting the application of such products for clinical treatment and the application of stem cells in major refractory diseases and regenerative medicine.

Purinergic Signaling and its Role in the Stem Cell Differentiation

Purinergic signaling is a mechanism in which extracellular purines and pyrimidines interact with specialized cell surface receptors known as purinergic receptors. These receptors are divided into two families of P1 and P2 receptors, each responding to different nucleosides and nucleotides. P1 receptors are activated by adenosine, while P2 receptors are activated by pyrimidine and purines. P2X receptors are ligand-gated ion channels, including seven subunits (P2X1-7). However, P2Y receptors are the G-protein coupled receptors comprising eight subtypes (P2Y1/2/4/6/11/12/13/14). The disorder in purinergic signaling leads to various health-related issues and diseases. In various aspects, it influences the activity of non-neuronal cells and neurons. The molecular mechanism of purinergic signaling provides insight into treating various human diseases. On the contrary, stem cells have been investigated for therapeutic applications. Purinergic signaling has shown promising effect in stem cell engraftment. The immune system promotes the autocrine and paracrine mechanisms and releases the significant factors essential for successful stem cell therapy. Each subtype of purinergic receptor exerts a beneficial effect on the damaged tissue. The most common effect caused by purinergic signaling is the proliferation and differentiation that treat different health-related conditions.

Fluorescence-Based Mono- and Multimodal Imaging for In Vivo Tracking of Mesenchymal Stem Cells

The advancement of stem cell therapy has offered transformative therapeutic outcomes for a wide array of diseases over the past decades. Consequently, stem cell tracking has become significant in revealing the mechanisms of action and ensuring safe and effective treatments. Fluorescence stands out as a promising choice for stem cell tracking due to its myriad advantages, including high resolution, real-time monitoring, and multi-fluorescence detection. Furthermore, combining fluorescence with other tracking modalities-such as bioluminescence imaging (BLI), positron emission tomography (PET), photoacoustic (PA), computed tomography (CT), and magnetic resonance (MR)-can address the limitations of single fluorescence detection. This review initially introduces stem cell tracking using fluorescence imaging, detailing various labeling strategies such as green fluorescence protein (GFP) tagging, fluorescence dye labeling, and nanoparticle uptake. Subsequently, we present several combinations of strategies for efficient and precise detection.

Proliferation-Related Features of the Human Mesenchymal Stem Cells Derived from Palatine Tonsils, Adipose Tissues, and Bone Marrow

BACKGROUND

Mesenchymal stem cells (MSCs) are widely used in regenerative medicine and cell-based transplantations. However, an in-depth comparison of the different MSC origins is lacking. This study aimed to compare the expression of adipose-derived (AMSCs), bone marrow-derived (BMSCs), and tonsil-derived (TMSCs) and evaluate whether TMSCs are good alternatives for AMSCs or BMSCs.

METHODS

We analyzed the expression levels of 47,000 transcripts in AMSCs (n = 4), BMSCs (n = 4), and TMSCs (n = 4) using GeneChip. Microarray data were analyzed using the LIMMA package to compare the TMSCs, AMSCs, and BMSCs. Hub genes were analyzed using STRING and Cytoscape. To ascertain the functional roles of AURKA and AURKB, small interfering RNA (siRNA) molecules specifically targeting AURKA and AURKB mRNA were synthesized and employed to induce knockdown of AURKA and AURKB in TMSC and AMSC. We analyzed the expression level of OCT4, SOX-2, and NANOG genes in TMSC and AMSCs by cell culture and real-time PCR.

RESULTS

We identified commonly increased 256 and decreased 160 genes in TMSCs from the differentially expressed genes (DEGs) between the TMSCs, AMSCs, and BMSCs. In the DEG-based protein-protein interaction and gene set enrichment analysis, hub genes (AURKA, AURKB, CDC20, and BUB1) highly expressed in TMSCs were enriched for development- and progression-related oocyte meiosis, the cell cycle, and ubiquitin-mediated proteolysis. In vitro analysis demonstrated that cells with downregulated expression of AURKA and AURKB exhibited a significant reduction in proliferation compared to control cells. However, silencing of the genes did not affect the differentiation capacity in TMSCs and AMSCs.

CONCLUSION

Our study compared MSCs of different origins to better understand the similarities and differences among these cell types.

A controllable gelatin-based microcarriers fabrication system for the whole procedures of MSCs amplification and tissue engineering

Biopolymer microbeads present substantial benefits for cell expansion, tissue engineering, and drug release applications. However, a fabrication system capable of producing homogeneous microspheres with high precision and controllability for cell proliferation, passaging, harvesting and downstream application is limited. Therefore, we developed a co-flow microfluidics-based system for the generation of uniform and size-controllable gelatin-based microcarriers (GMs) for mesenchymal stromal cells (MSCs) expansion and tissue engineering. Our evaluation of GMs revealed superior homogeneity and efficiency of cellular attachment, expansion and harvest, and MSCs expanded on GMs exhibited high viability while retaining differentiation multipotency. Optimization of passaging and harvesting protocols was achieved through the addition of blank GMs and treatment with collagenase, respectively. Furthermore, we demonstrated that MSC-loaded GMs were printable and could serve as building blocks for tissue regeneration scaffolds. These results suggested that our platform held promise for the fabrication of uniform GMs with downstream application of MSC culture, expansion and tissue engineering.

Therapeutic Benefits of Stem Cells and Exosomes for Sulfur-Mustard-Induced Tissue Damage

Sulfur mustard (SM) is a highly toxic chemical agent that causes severe tissue damage, particularly to the eyes, lungs, and skin. Despite advances in treatment, there is a need for more effective therapies for SM-induced tissue injury. Stem cell and exosome therapies are emerging as promising approaches for tissue repair and regeneration. Stem cells can differentiate into multiple cell types and promote tissue regeneration, while exosomes are small vesicles that can deliver therapeutic cargo to target cells. Several preclinical studies demonstrated the potential of stem cell, exosome, or combination therapy for various tissue injury, showing improvements in tissue repairing, inflammation, and fibrosis. However, there are also challenges associated with these therapies, such as the requirement for standardized methods for exosome isolation and characterization, the long-term safety and efficacy and reduced SM-induced tissue injury of these therapies. Stem cell or exosome therapy was used for SM-induced eye and lung injury. Despite the limited data on the use for SM-induced skin injury, this therapy is a promising area of research and may offer new treatment options in the future. In this review, we focused on optimizing these therapies, evaluating their safety and efficacy, and comparing their efficacy to other emerging therapeutic approaches potentially for SM-induced tissue injury in the eye, lung, and skin.

Effectiveness of RCTs Pooling Evidence on Mesenchymal Stem Cell (MSC) Therapeutic Applications During COVID-19 Epidemic: A Systematic Review

Background

Global pandemic identified as coronavirus disease 2019 (COVID-19) has resulted in a variety of clinical symptoms, from asymptomatic carriers to those with severe acute respiratory distress syndrome (SARS) and moderate upper respiratory tract symptoms (URTS). This systematic review aimed to determine effectiveness of stem cell (SC) applications among COVID-19 patients.

Methods

Multiple databases of PubMed, EMBASE, Science Direct, Google Scholar, Scopus, Web of Science, and Cochrane Library were used. Studies were screened, chosen, and included in this systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 flowchart diagram and PRISMA checklist. Included studies' quality was assessed employing Critical Appraisal Skills Programme (CASP) quality evaluation criteria for 14 randomized controlled trials (RCTs).

Results

Fourteen RCTs were performed between the years of 2020 to 2022, respectively, with a sample size n = 574 (treatment group (n = 318); control group (n = 256)) in multiple countries of Indonesia, Iran, Brazil, Turkey, China, Florida, UK, and France. The greatest sample size reported from China among 100 COVID-19 patients, while the lowest sample of 9 COVID-19 patients from Jakarta, Indonesia, and the patient's age ranges from 18 to 69 years. Studies applied to the type of SC were "Umbilical cord MSCs, MSCs secretome, MSCs, Placenta-derived MSCs, Human immature dental pulp SC, DW-MSC infusion, Wharton Jelly-derived MSCs". The injected therapeutic dose was 1 × 10⁶ cells/kg, 1 × 10⁷ cells/kg, 1 × 10⁵ cells/kg, and 1 million cells/kg as per the evidence from the different studies. Studies focused on demographic variables, clinical symptoms, laboratory tests, Comorbidities, respiratory measures, concomitant therapies, Sequential Organ Failure Assessment score, mechanical ventilation, body mass index, adverse events, inflammatory markers, and PaO₂/FiO₂ ratio were all recorded as study characteristics.

Conclusion

Clinical evidence on MSC's therapeutic applications during COVID-19 pandemic has proven to be a promising therapy for COVID-19 patient recovery with no consequences and applied as a routine treatment for challenging ailments.

Bcl-xL Promotes the Survival of Motor Neurons Derived from Neural Stem Cells

Neural stem cell (NSC) transplantation creates new hope for the treatment of neurodegenerative disorders by direct differentiation into neurons. However, this technique is limited by poor survival and functional neuron deficiency. In this research study, we generated pro-survival murine NSCs (mNSCs) via the ectopic expression of Bcl-xL. A doxycycline (Dox)-inducible Ngn2-Isl1-Lhx3 system was also integrated into the mNSC genome. The four gene-modified mNSCs can rapidly and effectively differentiate into motor neurons after Dox treatments. Ectopic Bcl-xL could resist replating-induced stress, glutamate toxicity, neuronal apoptosis and remarkably promote the survival of motor neurons. Taken together, we established genetically modified mNSCs with improved survival, which may be useful for motor neuron degenerative diseases.

A review of modern and Vedic practices on use of umbilical cord

Stromal cells possess unique properties to regenerate themselves and cure various chronic illnesses. An easily available and ethical source for procurement of stromal cells is umbilical cord blood which is now being stored for future use. Vedic texts also describe the cord blood as a source of life. However, Indian traditions seem to preserve one more alternative for storage and procurement of stromal cells. Traditionally, in many parts of India, the umbilical cord stump is dried and stored for future use. It is used as a medicine for some illness and to treat infertility. Since Indian traditions are an excerpt of Vedic science, it points towards the possible emergence of dried stump as an easy and cost-effective means for stromal cell procurement and storage. The present review compiles the literature available on these traditional practices and stresses upon the need of rigorous experimental and theoretical research in the area.

Alternatives to Antibiotics against Mycobacterium abscessus

Mycobacterium abscessus complex is extremely difficult to treat. Intrinsic and acquired bacterial resistance makes this species one of the most challenging pathogens and treatments last from months to years, associated with potential risky antibiotic toxicity and a high number of failures. Nonantibiotic antimicrobial agents against this microorganism have recently been studied so as to offer an alternative to current drugs. This review summarizes recent research on different strategies such as host modulation using stem cells, photodynamic therapy, antibiofilm therapy, phage therapy, nanoparticles, vaccines and antimicrobial peptides against M. abscessus both in vitro and in vivo.

Stem Cells in Clinical Trials on Neurological Disorders: Trends in Stem Cells Origins, Indications, and Status of the Clinical Trials

Neurological diseases can significantly reduce the quality and duration of life. Stem cells provide a promising solution, not only due to their regenerative features but also for a variety of other functions, including reducing inflammation and promoting angiogenesis. Although only hematopoietic cells have been approved by the FDA so far, the number of trials continues to expand. We analyzed 492 clinical trials and illustrate the trends in stem cells origins, indications, and phase and status of the clinical trials. The most common neurological disorders treated with stem cells were injuries of brain, spinal cord, and peripheral nerves (14%), stroke (13%), multiple sclerosis (12%), and brain tumors (11%). Mesenchymal stem cells dominated (83%) although the choice of stem cells was highly dependent on the neurological disorder. Of the 492 trials, only two trials have reached phase 4, with most of all other trials being in phases 1 or 2, or transitioning between them (83%). Based on a comparison of the obtained results with similar works and further analysis of the literature, we discuss some of the challenges and future directions of stem cell therapies in the treatment of neurological diseases.

Oxidative Stress in Ageing and Chronic Degenerative Pathologies: Molecular Mechanisms Involved in Counteracting Oxidative Stress and Chronic Inflammation

Ageing and chronic degenerative pathologies demonstrate the shared characteristics of high bioavailability of reactive oxygen species (ROS) and oxidative stress, chronic/persistent inflammation, glycation, and mitochondrial abnormalities. Excessive ROS production results in nucleic acid and protein destruction, thereby altering the cellular structure and functional outcome. To stabilise increased ROS production and modulate oxidative stress, the human body produces antioxidants, “free radical scavengers”, that inhibit or delay cell damage. Reinforcing the antioxidant defence system and/or counteracting the deleterious repercussions of immoderate reactive oxygen and nitrogen species (RONS) is critical and may curb the progression of ageing and chronic degenerative syndromes. Various therapeutic methods for ROS and oxidative stress reduction have been developed. However, scientific investigations are required to assess their efficacy. In this review, we summarise the interconnected mechanism of oxidative stress and chronic inflammation that contributes to ageing and chronic degenerative pathologies, including neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), cardiovascular diseases CVD, diabetes mellitus (DM), and chronic kidney disease (CKD). We also highlight potential counteractive measures to combat ageing and chronic degenerative diseases.

Nebulization Therapy with Umbilical Cord Mesenchymal Stem Cell-Derived Exosomes for COVID-19 Pneumonia

Background

Scientists have been facing numerous challenges in the development of an effective therapeutic strategy for the treatment of COVID-19 pneumonia. Several studies have suggested that improving patient immunity and reducing lung injury induced by SARS-CoV-2 may be effective for treating patients with COVID-19.

Methods

A pilot trial of nebulization therapy with exosomes of mesenchymal stem cells (MSCs) was performed on seven patients with COVID-19 pneumonia. Exosomes secreted from MSCs were collected and purified using multiple ultrafiltration steps. All patients were treated with nebulization of MSC-derived exosomes, and primary safety and efficacy outcomes were evaluated.

Results

Our clinical study demonstrated that nebulization of MSC-derived exosomes is a novel method that might be utilized in the treatment of COVID-19 pneumonia. Nebulization of MSC-derived exosomes did not induce acute allergic or secondary allergic reactions but did promote the absorption of pulmonary lesions and reduce the duration of hospitalization for mild cases of COVID-19 pneumonia.

Conclusions

Nebulization of MSC-derived exosomes is a safe, effective, and simple method, and their application at the beginning of treatment may be more beneficial.

Trial Registration

Chinese Clinical Trial Registry, ChiCTR2000030261. Registered on 26 February 2020.

Graphical Abstract

Cell secretomes for wound healing and tissue regeneration: Next generation acellular based tissue engineered products

Wound represents a significant socioeconomic burden for both affected individuals and as a whole healthcare system. Accordingly, stem cells have garnered attention due to their differentiation capacity and ability to aid tissue regeneration by releasing biologically active molecules, found in the cells' cultivated medium which known as conditioned medium (CM) or secretomes. This acellular approach provides a huge advantage over conventional treatment options, which are mainly used cellular treatment at wound closure. Interestingly, the secretomes contained the cell-secreted proteins such as growth factors, cytokines, chemokines, extracellular matrix (ECM), and small molecules including metabolites, microvesicles, and exosomes. This review aims to provide a general view on secretomes and how it is proven to have great potential in accelerating wound healing. Utilizing the use of secretomes with its secreted proteins and suitable biomaterials for fabrications of acellular skin substitutes can be promising in treating skin loss and accelerate the healing process.

Extracellular vesicles in the treatment of neurological disorders

Extracellular vesicles (EVs) are small, cell-derived membranous particles containing various nucleic acids, proteins, and lipids that play essential roles in intercellular communication. Evidence indicating that part of the regenerative benefit from stem cell therapy arises through EVs released from transplanted cells created interest in using EVs for clinical applications. EVs from various cellular sources, including mesenchymal stem cells, neural stem cells, and glia, are efficacious in models of neurological disease. In these models, EVs attenuate reactive gliosis, neuronal death, pro-inflammatory signaling, as well as reduce cognitive, behavioral, and motor deficits. EVs are naturally permeable to the blood-brain barrier and can be modified to contain molecules of interest, thereby also serving as a vehicle to transport therapeutics into the brain. This review summarizes the current state of research using EVs as a treatment in models of neurological disorders and highlights considerations for future research.

In Vitro Culturing of Adult Stem Cells: The Importance of Serum and Atmospheric Oxygen

Adult stem cells are undifferentiated cells found in many different tissues in the adult human and animal body and are thought to be important for replacing damaged and dead cells during life. Due to their differentiation abilities, they have significant potential for regeneration and consequently therapeutic potential in various medical conditions. Studies on in vitro cultivation of different types of adult stem cells have shown that they have specific requirements for optimal proliferation and stemness maintenance as well as induced differentiation. The main factors affecting the success of stem cell cultivation are the composition of the growth medium, including the presence of serum, temperature, humidity, and contact with other cells and the composition of the atmosphere in which the cells grow. In this chapter, we review the literature and describe our own experience regarding the influence of the presence of fetal bovine serum in the medium and the oxygen concentration in the atmosphere on the stemness maintenance and survival of adult stem cells from various tissue sources such as adipose tissue, muscle, brain, and testicular tissue.

Comparing the Therapeutic Potential of Stem Cells and their Secretory Products in Regenerative Medicine

Cell therapy involves the transplantation of human cells to replace or repair the damaged tissues and modulate the mechanisms underlying disease initiation and progression in the body. Nowadays, many different types of cell-based therapy are developed and used to treat a variety of diseases. In the past decade, cell-free therapy has emerged as a novel approach in regenerative medicine after the discovery that the transplanted cells exerted their therapeutic effect mainly through the secretion of paracrine factors. More and more evidence showed that stem cell-derived secretome, i.e., growth factors, cytokines, and extracellular vesicles, can repair the injured tissues as effectively as the cells. This finding has spurred a new idea to employ secretome in regenerative medicine. Despite that, will cell-free therapy slowly replace cell therapy in the future? Or are these two modes of treatment still needed to address different diseases and conditions? This review provides an indepth discussion about the values of stem cells and secretome in regenerative medicine. In addition, the safety, efficacy, advantages, and disadvantages of using these two modes of treatment in regenerative medicine are also critically reviewed.

A Review on the Role of Artificial Intelligence in Stem Cell Therapy: An Initiative for Modern Medicines

Stem Cells (SCs) show a wide range of applications in the treatment of numerous diseases, including neurodegenerative diseases, diabetes, cardiovascular diseases, cancer, etc. SC related research has gained popularity owing to the unique characteristics of self-renewal and differentiation. Artificial Intelligence (AI), an emerging field of computer science and engineering, has shown potential applications in different fields like robotics, agriculture, home automation, healthcare, banking, and transportation since its invention. This review aims to describe the various applications of AI in SC biology, including understanding the behavior of SCs, recognizing individual cell type before undergoing differentiation, characterization of SCs using mathematical models and prediction of mortality risk associated with SC transplantation. This review emphasizes the role of neural networks in SC biology and further elucidates the concepts of machine learning and deep learning and their applications in SC research.

The Use of Mesenchymal Stem Cells and their Derived Extracellular Vesicles in Cardiovascular Disease Treatment

BACKGROUND

Cardiovascular disease (CVD), including disorders of cardiac muscle and vascular, is the major cause of death globally. Many unsuccessful attempts have been made to intervene in the disease's pathogenesis and treatment. Stem cell-based therapies, as a regeneration strategy, cast a new hope for CVD treatment. One of the most well-known stem cells is mesenchymal stem cells (MSCs), classified as one of the adult stem cells and can be obtained from different tissues. These cells have superior properties, such as proliferation and highly specialized differentiation. On the other hand, they have the potential to modulate the immune system and anti-inflammatory activity. One of their most important features is the secreting the extracellular vesicles (EVs) like exosomes (EXOs) as an intercellular communication system mediating the different physiological and pathophysiological affairs.

METHODS

In this review study, the importance of MSC and its secretory exosomes for the treatment of heart disease has been together and specifically addressed and the use of these promising natural and accessible agents is predicted to replace the current treatment modalities even faster than we imagine.

RESULTS

MSC derived EXOs by providing a pro-regenerative condition allowing innate stem cells to repair damaged tissues successfully. As a result, MSCs are considered as the appropriate cellular source in regenerative medicine. In the plethora of experiments, MSCs and MSC-EXOs have been used for the treatment and regeneration of heart diseases and myocardial lesions.

CONCLUSION

Administration of MSCs has been provided a replacement therapeutic option for heart regeneration, obtaining great attention among the basic researcher and the medical doctors.

Xeno-Free Human Wharton's Jelly Mesenchymal Stromal Cells Maintain Their Characteristic Properties after Long-Term Cryopreservation

Objective

The past decade has witnessed a rapid growth in harnessing the potential of adult stem cells for regenerative medicine. An investigational new drug (IND) or a regenerative medicine advanced therapy (RMAT) product must fulfil many requirements, such as stability studies, after cryopreservation. Such studies are important to ascertain the utility of off-the-shelf allogeneic cells for clinical applications. The present work describes a complete characterisation of xeno- free human Wharton’s Jelly mesenchymal stromal cells (hWJ-MSCs) before and up to 28 months post-cryopreservation.

Materials and Methods

In this experimental study, culture methods that involved plasma derived human serum and recombinant trypsin were used to develop clinical grade cells. Complete cell characterisation involved flow cytometry studies for viability, positive and negative markers, colony forming unit (CFU) potential, population doubling time (PDT), soft agar assay to evaluate in vitro tumourigenicity, karyotype analysis and differentiation studies which were performed before and at 6, 12, 18 and 28 months post-cryopreservation.

Results

Our data showed consistency in the flow cytometry, CFU assay, PDT, soft agar assay, karyotyping and differentiation studies.

Conclusion

Using our protocols for extended xeno-free culture and cryopreservation of hWJ-MSCs, we could establish the shelf life of the cell-based product for up to 28 months.

Effect of Biomedical Materials in the Implementation of a Long and Healthy Life Policy

This paper is divided into seven main parts. Its purpose is to review the literature to demonstrate the importance of developing bioengineering and global production of biomaterials to care for the level of healthcare in the world. First, the general description of health as a universal human value and assumptions of a long and healthy life policy is presented. The ethical aspects of the mission of medical doctors and dentists were emphasized. The coronavirus, COVID-19, pandemic has had a significant impact on health issues, determining the world’s health situation. The scope of the diseases is given, and specific methods of their prevention are discussed. The next part focuses on bioengineering issues, mainly medical engineering and dental engineering, and the need for doctors to use technical solutions supporting medicine and dentistry, taking into account the current stage Industry 4.0 of the industrial revolution. The concept of Dentistry 4.0 was generally presented, and a general Bioengineering 4.0 approach was suggested. The basics of production management and the quality loop of the product life cycle were analyzed. The general classification of medical devices and biomedical materials necessary for their production was presented. The paper contains an analysis of the synthesis and characterization of biomedical materials supporting medicine and dentistry, emphasizing additive manufacturing methods. Numerous examples of clinical applications supported considerations regarding biomedical materials. The economic conditions for implementing various biomedical materials groups were supported by forecasts for developing global markets for biomaterials, regenerative medicine, and tissue engineering. In the seventh part, recapitulation and final remarks against the background of historical retrospection, it was emphasized that the technological processes of production and processing of biomedical materials and the systematic increase in their global production are a determinant of the implementation of a long and healthy policy.

Quality by design to define critical process parameters for mesenchymal stem cell expansion

Stem cell-based therapeutic products could be the key to treat the deadliest current pathologies, ranging from neuro-degenerative to respiratory diseases. However, in order to bring these innovative therapeutics to a commercialization stage, reproducible manufacturing of high quality cell products is required. Although advances in cell culture techniques have led to more robust production processes and dramatically accelerated the development of early-phase clinical studies, challenges remain before regulatory approval, particularly to define and implement science-based quality standards (essential pre-requisites for national health agencies). In this regard, using new methodologies, such as Quality By Design (QBD), to build the production process around drug quality, could significantly reduce the chance of product rejection. This review-based work aims to perform a QBD approach to Mesenchymal Stem Cell (MSC) manufacturing in standard two-dimensional flasks, using published studies which have determined the impact of individual process parameters on defined Critical Quality Attributes (CQA). Along with this bibliographic analysis, parameter criticality was determined during the two main manufacturing stages (cell extraction and cell amplification) along with an overall classification in view of identifying the Critical Process Parameters (CPP). The analysis was performed in view of an improved standardization between research teams, and should contribute to reduce the gap towards compliant Good Manufacturing Practice (cGMP) manufacturing.

Innervation of Meissner's corpuscles and Merkel -cells by transplantation of embryonic dorsal root ganglion cells after peripheral nerve section in rats

Transplantation of embryonic motor neurons has been shown to improve motor neuron survival and innervation of neuromuscular junctions in peripheral nerves. However, there have been no reports regarding transplantation of sensory neurons and innervation of sensory receptors. Therefore, we hypothesized that the transplantation of embryonic sensory neurons may improve sensory neurons in the skin and innervate Merkel cells and Meissner's corpuscles. We obtained sensory neurons from dorsal root ganglia of 14-day rat embryos. We generated a rat model of Wallerian-degeneration by performing sciatic nerve transection and waiting for one week after. Six months after cell transplantation, we performed histological and electrophysiological examinations in naïve control, surgical control, and cell transplantation groups. The number of nerve fibers in the papillary dermis and epidermal-dermal interface was significantly greater in the cell transplantation than in the surgical control group. The percent of Merkel cells with nerve terminals, as well as the average number of Meissner corpuscles with nerve terminals, were higher in the cell transplantation than in the surgical control group, but differences were not significant between the two groups. Moreover, the amplitude and latency of sensory conduction velocity were evoked in rats of the cell transplantation group. We demonstrated that the transplantation of embryonic dorsal root ganglion cells improved sensory nerve fiber number and innervation of Merkel cells and Meissner's corpuscles in peripheral nerves.

Amniotic fluid stem cells as a novel strategy for the treatment of fetal and neonatal neurological diseases

Even in the context of modern medicine, infants with fetal and neonatal neurological diseases such as cerebral palsy and myelomeningocele suffer serious long-lasting impairment due to the irreversible neuronal damage. The promotion of neurologically intact survival in patients with perinatal intractable neurological diseases requires the development of novel strategies. One promising strategy involves the use of human amniotic fluid stem cells (hAFSCs), which have attracted much attention in recent years and are known to exert anti-inflammatory and neuroprotective effects. In recent years, the therapeutic effects of hAFSCs on fetal-neonatal neurological diseases have become evident as per intense research efforts by our group and others. Specifically, hAFSCs administered into the nasal cavity migrated to the brain and controlled local inflammation in a rodent model of neonatal hypoxic-ischemic encephalopathy. In contrast, hAFSCs administered intraperitoneally did not migrate to the brain; they rather formed spheroids in the abdominal cavity, resulting in the suppression of systemic inflammation (including in the brain) via the secretion of anti-inflammatory cytokines in concert with peritoneal macrophages in a rodent model of periventricular leukomalacia. Moreover, studies in a rat model of myelomeningocele suggested that hAFSCs administered in utero secreted hepatocyte growth factor and protected the exposed spinal cord during pregnancy. Importantly, autologous hAFSCs, whose use for fetal-neonatal treatment does not raise ethical issues, can be collected during pregnancy and prepared in sufficient numbers for therapeutic use. This article outlines the results of preclinical research on fetal stem cell therapy, mainly involving hAFSCs, in the context of perinatal neurological diseases.

High-precision multiclass cell classification by supervised machine learning on lectin microarray data

INTRODUCTION

Establishment of a cell classification platform for evaluation and selection of human pluripotent stem cells (hPSCs) is of great importance to assure the efficacy and safety of cell-based therapy. In our previous work, we introduced a discriminant function that evaluates pluripotency from the cells' glycome. However, it is not yet suitable for general use.

METHODS

The current study aims to establish a high-precision cell classification platform introducing supervised machine learning and test the platform on glycome analysis as a proof-of-concept study. We employed linear classification and neural network to the lectin microarray data from 1577 human cells and categorized them into five classes including hPSCs.

RESULTS

The linear-classification-based model and the neural-network-based model successfully predicted the sample type with accuracies of 89% and 97%, respectively.

CONCLUSIONS

Because of the high recognition accuracies and the small amount of computing resources required for these analyses, our platform can be a high precision conventional cell classification system for hPSCs.

Bidirectional Enhancement of Cell Proliferation Between Iron Oxide Nanoparticle-Labeled Mesenchymal Stem Cells and Choroid Plexus in a Cell-Based Therapy Model of Ischemic Stroke

PURPOSE

Stem cell therapy for ischemic stroke has shown success in experimental settings, but its translation into clinical practice is challenging. The choroid plexus (CP) plays a regulatory role in neural regeneration. Mesenchymal stem cells (MSCs) promote neurogenesis in the ventricular-subventricular zone. However, it is unclear whether MSCs interact with the CP in brain tissue repair.

METHODS

Rat (r)MSCs were labeled with iron oxide nanoparticles (IONs) and transduced with red fluorescent protein, and then injected into the brain of rats with ischemic stroke and monitored over time by magnetic resonance imaging. The functional recovery of rats was determined by the corner test score, Modified Neurological Severity score, and stroke volume. MSCs and CP were also co-cultured for 14 days, and the medium was analyzed with a cytokine array.

RESULTS

In vivo imaging and histologic analysis revealed that ION-labeled MSCs were mainly located at the injection site and migrated to the infarct area and to the CP. Functional recovery was greater in rats treated with MSCs as compared to those that received mock treatment. Bidirectional enhancement of proliferation in MSCs and CP was observed in the co-culture; moreover, MSCs migrated to the CP. Cytokine analysis revealed elevated levels of proliferation- and adhesion-related cytokines and chemokines in the culture medium. Wikipathway predictions indicated that insulin-like growth factor 1/Akt signaling (WP3675), chemokine signaling pathway (WP2292), and spinal cord injury (WP2432) are involved in the increased proliferation and migration of MSCs co-cultured with the CP.

CONCLUSION

Crosstalk with the CP enhances MSC proliferation and migration in a transwell assay. Moreover, MRI reveals MSC migration towards the CP in an ischemic stroke model. The secreted factors resulting from this interaction have therapeutic potential for promoting functional recovery in the brain after ischemic stroke.

In vitro Studies of Transendothelial Migration for Biological and Drug Discovery

Inflammatory diseases and cancer metastases lack concrete pharmaceuticals for their effective treatment despite great strides in advancing our understanding of disease progression. One feature of these disease pathogeneses that remains to be fully explored, both biologically and pharmaceutically, is the passage of cancer and immune cells from the blood to the underlying tissue in the process of extravasation. Regardless of migratory cell type, all steps in extravasation involve molecular interactions that serve as a rich landscape of targets for pharmaceutical inhibition or promotion. Transendothelial migration (TEM), or the migration of the cell through the vascular endothelium, is a particularly promising area of interest as it constitutes the final and most involved step in the extravasation cascade. While in vivo models of cancer metastasis and inflammatory diseases have contributed to our current understanding of TEM, the knowledge surrounding this phenomenon would be significantly lacking without the use of in vitro platforms. In addition to the ease of use, low cost, and high controllability, in vitro platforms permit the use of human cell lines to represent certain features of disease pathology better, as seen in the clinic. These benefits over traditional pre-clinical models for efficacy and toxicity testing are especially important in the modern pursuit of novel drug candidates. Here, we review the cellular and molecular events involved in leukocyte and cancer cell extravasation, with a keen focus on TEM, as discovered by seminal and progressive in vitro platforms. In vitro studies of TEM, specifically, showcase the great experimental progress at the lab bench and highlight the historical success of in vitro platforms for biological discovery. This success shows the potential for applying these platforms for pharmaceutical compound screening. In addition to immune and cancer cell TEM, we discuss the promise of hepatocyte transplantation, a process in which systemically delivered hepatocytes must transmigrate across the liver sinusoidal endothelium to successfully engraft and restore liver function. Lastly, we concisely summarize the evolving field of porous membranes for the study of TEM.

The Immune System and Its Contribution to Variability in Regenerative Medicine

The immune system plays a critical role in directing tissue repair and regeneration outcomes. Tissue engineering technologies that are designed to promote new tissue growth will therefore be impacted by immune factors that are present in patients both locally at the site of intervention and systemically. The immune state of patients can be influenced by many factors, including infection, nutrition, and other disease comorbidities. As a result, the immune state is highly variable and may be a source of variability in tissue-engineered products in the clinic, which is not found in preclinical models. In this review, we will summarize key immune cells and evidence of their activity in tissue repair and potential in tissue engineering systems. We also discuss how clinical translation of tissue engineering strategies, in particular stem cells, helped elucidate the importance of the immune system. With increased understanding of the immune system's role in repair and tissue engineering systems, it will likely become a therapeutic target and component of future therapies.

Mitochondrial donation in translational medicine; from imagination to reality

The existence of active crosstalk between cells in a paracrine and juxtacrine manner dictates specific activity under physiological and pathological conditions. Upon juxtacrine interaction between the cells, various types of signaling molecules and organelles are regularly transmitted in response to changes in the microenvironment. To date, it has been well-established that numerous parallel cellular mechanisms participate in the mitochondrial transfer to modulate metabolic needs in the target cells. Since the conception of stem cells activity in the restoration of tissues’ function, it has been elucidated that these cells possess a unique capacity to deliver the mitochondrial package to the juxtaposed cells. The existence of mitochondrial donation potentiates the capacity of modulation in the distinct cells to achieve better therapeutic effects. This review article aims to scrutinize the current knowledge regarding the stem cell’s mitochondrial transfer capacity and their regenerative potential.

Corneal endothelial dysfunction: Evolving understanding and treatment options

The cornea is exquisitely designed to protect the eye while transmitting and focusing incoming light. Precise control of corneal hydration by the endothelial cell layer that lines the inner surface of the cornea is required for optimal transparency, and endothelial dysfunction or damage can result in corneal edema and visual impairment. Advances in corneal transplantation now allow selective replacement of dysfunctional corneal endothelium, providing rapid visual rehabilitation. A series of technique improvements have minimized complications and various adaptations allow use even in eyes with complicated anatomy. While selective endothelial keratoplasty sets a very high standard for safety and efficacy, a shortage of donor corneas in many parts of the world restricts access, prompting a search for alternatives. Clinical trials are underway to evaluate the potential for self-recovery after removal of dysfunctional central endothelium in patients with healthy peripheral endothelium. Various approaches to using cultured human corneal endothelial cells are also in clinical trials; these aim to multiply cells from a single donor cornea for use in potentially hundreds of patients. Pre-clinical studies are underway with induced pluripotent stem cells, endothelial stem cell regeneration, gene therapy, anti-sense oligonucleotides, and various biologic/pharmacologic approaches designed to treat, prevent, or retard corneal endothelial dysfunction. The availability of more therapeutic options will hopefully expand access around the world while also allowing treatment to be more precisely tailored to each individual patient.

Vascular endothelial growth factor sustained delivery augmented cell therapy outcomes of cardiac progenitor cells for myocardial infarction

Cell therapy has become a novel promising approach for improvement of cardiac functional capacity in the instances of ventricular remodeling and fibrosis caused by episodes of coronary artery occlusion and hypoxia. The challenge toward enhancing cell engraftment as well as formation of functional tissue, however, necessitated combinatorial approaches. Here, we complemented human embryonic stem cell-derived cardiac progenitor cell (hESC-CPC) therapy by heparin-conjugated, vascular endothelial growth factor (VEGF)-loaded fibrin hydrogel as VEGF delivery system. Transplantation of these cardiac committed cells along with sustained VEGF release could surpass the cardiac repair effects of each constituent alone in a rat model of acute myocardial infarction. The histological sections of rat hearts revealed improved vascularization as well as inclusion of hESC-CPC-derived cardiomyocytes, endothelial, and smooth muscle cells in host myocardium. Thus, co-transplantation of hESC-CPC and proangiogenic factor by a suitable delivery rate may resolve the shortcomings of conventional cell therapy.

A cell-based combination product for the repair of large bone defects

Regenerative cell-based implants using periosteum-derived stem cells were developed for the treatment of large 3 cm fresh and 4.5 centimeter biological compromised bone gaps in a tibial sheep model and compared with an acellular ceramic-collagen void filler. It was hypothesized that the latter is insufficient to heal large skeletal defects due to reduced endogenous biological potency. To this purpose a comparison was made between the ceramic dicalciumphosphate scaffold (CopiOs®) as such, the same ceramic coated with clinical grade Bone Morphogenetic Protein 2 and 6 (BMP) only or a BMP coated cell-seeded combination product. These implants were evaluated in 2 sheep models, a fresh 3 cm critical size tibial defect and a 4.5 cm biologically exhausted tibial defect. For the groups in which growth factors were applied, BMP-6 was chosen at a dose of 344 μg for 3 cm and 1.500 μg or 3.800 μg for 4.5 cm defects. An additional group in the 4.5 cm defect was tested using BMP-2 in a dose of 1.500 μg. For all the cell based implants autologous periosteum-derived cells were used which were cultured in monolayer during 6 weeks. For the fresh defect 408 million cells and for the biologically exhausted tibial defect 612 million cells were drop-seeded on the BMP coated scaffolds. Bone healing was studied during 16 weeks postimplantation, using standard radiographs. While fresh defects responded to all treatments, regardless the use of cells, the biologically hampered defects responded in half of the cases and only if the BMP-cell combination product was used, supporting the concept that cell-based therapies may become attractive in treating defects with a compromised biological status.

Optical coherence tomography and fluorescence microscopy dual-modality imaging for in vivo single-cell tracking with nanowire lasers

Emerging cell-based therapies such as stem cell therapy and immunotherapy have attracted broad attention in both biological research and clinical practice. However, a long-standing technical gap of cell-based therapies is the difficulty of directly assessing treatment efficacy via tracking therapeutically administered cells. Therefore, imaging techniques to follow the in vivo distribution and migration of cells are greatly needed. Optical coherence tomography (OCT) is a clinically available imaging technology with ultrahigh-resolution and excellent imaging depth. It also shows great potential for in vivo cellular imaging. However, due to the homogeneity of current OCT cell labeling contrast agents (such as gold and polymer nanoparticles), only the distribution of entire cell populations can be observed. Precise tracking of the trajectory of individual single cells is not possible with such conventional contrast agents. Microlasers may provide a route to track unique cell identifiers given their small size, high emission intensities, rich emission spectra, and narrow linewidths. Here, we demonstrate that nanowire lasers internalized by cells provide both OCT and fluorescence signal. In addition, cells can be individually identified by the unique lasing emission spectra of the nanowires that they carry. Furthermore, single cell migration trajectories can be monitored both in vitro and in vivo with OCT and fluorescence microscopy dual-modality imaging system. Our study demonstrates the feasibility of nanowire lasers combined with the dual-modality imaging system for in vivo single cell tracking with a high spatial resolution and identity verification, an approach with great utility for stem cell and immunomodulatory therapies.

Rapid, practical and safe isolation of adipose derived stem cells

We compared migration, proliferation, growth curve, confluency and differentiation into adipogenic, osteogenic and chondrogenic cell lineages of mesenchymal stem cells derived from adipose tissue cultured in scratched and nonscratched cell culture flasks. Mesenchymal stem cells were isolated from rat adipose tissue using a nonenzymatic method. We investigated two groups. For the control group, minced adipose tissue was implanted conventionally onto the surface of standard plastic cell culture flasks. For the experimental group, the tissues were cultured in flasks with a scratched surface. We found that scratched flasks promoted cell migration, proliferation and confluency. Our findings suggest that scratched flasks may be used to ensure rapid, practical and safe isolation of adipose tissue-derived stem cells.

Mechanosensing of Mechanical Confinement by Mesenchymal-Like Cells

Mesenchymal stem cells (MSCs) and tumor cells have the unique capability to migrate out of their native environment and either home or metastasize, respectively, through extremely heterogeneous environments to a distant location. Once there, they can either aid in tissue regrowth or impart an immunomodulatory effect in the case of MSCs, or form secondary tumors in the case of tumor cells. During these journeys, cells experience physically confining forces that impinge on the cell body and the nucleus, ultimately causing a multitude of cellular changes. Most drastically, confining individual MSCs within hydrogels or confining monolayers of MSCs within agarose wells can sway MSC lineage commitment, while applying a confining compressive stress to metastatic tumor cells can increase their invasiveness. In this review, we seek to understand the signaling cascades that occur as cells sense confining forces and how that translates to behavioral changes, including elongated and multinucleated cell morphologies, novel migrational mechanisms, and altered gene expression, leading to a unique MSC secretome that could hold great promise for anti-inflammatory treatments. Through comparison of these altered behaviors, we aim to discern how MSCs alter their lineage selection, while tumor cells may become more aggressive and invasive. Synthesizing this information can be useful for employing MSCs for therapeutic approaches through systemic injections or tissue engineered grafts, and developing improved strategies for metastatic cancer therapies.

Extracellular matrix mimicking polycaprolactone-chitosan nanofibers promote stemness maintenance of mesenchymal stem cells via spheroid formation

The development of clinical applications has led to a perpetual increase in the demand for mesenchymal stem cells (MSCs). However, the ex vivo expansion of MSCs while maintaining their stemness and differentiation potential remains an immense challenge. MSCs require high cell density for their intercellular communication and specific physico-chemical cues from the surrounding environment for spheroid formation in order to maintain their stemness. Inadequacy of the traditional in vitro cell culture method (tissue culture plastic surface) to fulfill any of these special requirements is responsible for inducing the loss of stem cell properties of the MSCs over time. In this study, we propose that glucosaminoglycan (GAG) mimicking ultrafine nanofibers could support the spheroid culture for in vitro human MSC expansion. The geometrical and biochemical properties of nanofibers provide biomimicking cues to MSCs, as well as enhance cell-cell interactions and stimulate spheroid formation in MSCs, which subsequently result in increased cell proliferation, enhanced expression of stem cell markers and maintenance of their multilineage differentiation potential. Furthermore, close monitoring of the behavior of MSCs on nanofibers serves as the key to understand their mode of action in niche formation. Interestingly, GAG mimicking substrate stimulated MSCs for long-distance intercellular communication via 'tunneling tubes', their subsequent migration and niche formation. These kinds of cellular interactions over long distances have rarely been observed in MSCs to provide better insight for future studies on MSC niche. Furthermore, PCL-CHT nanofibers were observed to be as conducive to use as tissue culture polystyrene for stem cell expansion. Overall, these polymeric nanofibers provide a more relevant, convenient and more suitable substrate than the conventional monolayer culture for in vitro MSC expansion.

The effect of magnetic field exposure on differentiation of magnetite nanoparticle-loaded adipose-derived stem cells

Magnetic nanoparticles (MNPs) are versatile tools for various applications in biotechnology and nanomedicine. MNPs-mediated cell tracking, targeting and imaging are increasingly studied for regenerative medicine applications in cell therapy and tissue engineering. Mechanical stimulation influences mesenchymal stem cell differentiation. Here we show that MNPs-mediated magneto-mechanical stimulation of human primary adipose derived stem cells (ADSCs) exposed to variable magnetic field (MF) influences their adipogenic and osteogenic differentiation. ADSCs loaded with biocompatible magnetite nanoparticles of 6.6 nm, and with an average load of 21 picograms iron/cell were exposed to variable low intensity (0.5 mT - LMF) and higher intensity magnetic fields (14.7 and 21.6 mT - HMF). Type, duration, intensity and frequency of MF differently affect differentiation. Short time (2 days) intermittent exposure to LMF increases adipogenesis while longer (7 days) intermittent as well as continuous exposure favors osteogenesis. HMF (21.6 mT) short time intermittent exposure favors osteogenesis. Different exposure protocols can be used to increase differentiation dependently on expected results. Magnetic remotely-actuated MNPs up-taken by ADSCs promotes the shift towards osteoblastic lineage. ADSCs-MNPs under MF exposure could be used for enabling osteoblastic conversion during cell therapy for systemic osteoporosis. Current results enable further in vivo studies investigating the role of remotely-controlled magnetically actuated ADSCs-MNPs for the treatment of osteoporosis.

Multipotency of mouse trophoblast stem cells

BACKGROUND

In a number of disease processes, the body is unable to repair injured tissue, promoting the need to develop strategies for tissue repair and regeneration, including the use of cellular therapeutics. Trophoblast stem cells (TSCs) are considered putative stem cells as they differentiate into other subtypes of trophoblast cells. To identify cells for future therapeutic strategies, we investigated whether TSCs have properties of stem/progenitor cells including self-renewal and the capacity to differentiate into parenchymal cells of fetal organs, in vitro and in vivo.

METHODS

TSCs were isolated using anti-CD117 micro-beads, from embryonic day 18.5 placentas. In vitro, CD117+ TSCs were cultured, at a limiting dilution in growth medium for the development of multicellular clones and in specialized medium for differentiation into lung epithelial cells, cardiomyocytes, and retinal photoreceptor cells. CD117+ TSCs were also injected in utero into lung, heart, and the sub-retinal space of embryonic day 13.5 fetuses, and the organs were harvested for histological assessment after a natural delivery.

RESULTS

We first identified CD117+ cells within the labyrinth zone and chorionic basal plate of murine placentas in late pregnancy, embryonic day 18.5. CD117+ TSCs formed multicellular clones that remained positive for CD117 in vitro, consistent with self-renewal properties. The clonal cells demonstrated multipotency, capable of differentiating into lung epithelial cells (endoderm), cardiomyocytes (mesoderm), and retinal photoreceptor cells (ectoderm). Finally, injection of CD117+ TSCs in utero into lungs, hearts, and the sub-retinal spaces of fetuses resulted in their engraftment on day 1 after birth, and the CD117+ TSCs differentiated into lung alveolar epithelial cells, heart cardiomyocytes, and retina photoreceptor cells, corresponding with the organs in which they were injected.

CONCLUSIONS

Our findings demonstrate that CD117+ TSCs have the properties of stem cells including clonogenicity, self-renewal, and multipotency. In utero administration of CD117+ TSCs engraft and differentiate into resident cells of the lung, heart, and retina during mouse development.

Insulin-Producing Cell Transplantation Platform for Veterinary Practice

Diabetes mellitus (DM) remains a global concern in both human and veterinary medicine. Type I DM requires prolonged and consistent exogenous insulin administration to address hyperglycemia, which can increase the risk of diabetes complications such as retinopathy, nephropathy, neuropathy, and heart disorders. Cell-based therapies have been successful in human medicine using the Edmonton protocol. These therapies help maintain the production of endogenous insulin and stabilize blood glucose levels and may possibly be adapted to veterinary clinical practice. The limited number of cadaveric pancreas donors and the long-term use of immunosuppressive agents are the main obstacles for this protocol. Over the past decade, the development of potential therapies for DM has mainly focused on the generation of effective insulin-producing cells (IPCs) from various sources of stem cells that can be transplanted into the body. Another successful application of stem cells in type I DM therapies is transplanting generated IPCs. Encapsulation can be an alternative strategy to protect IPCs from rejection by the body due to their immunoisolation properties. This review summarizes current concepts of IPCs and encapsulation technology for veterinary clinical application and proposes a potential stem-cell-based platform for veterinary diabetic regenerative therapy.

Non-invasively enhanced intracranial transplantation of mesenchymal stem cells using focused ultrasound mediated by overexpression of cell-adhesion molecules

Although there have been reports of promising results regarding the transplantation of mesenchymal stem cells (MSCs) for neurodegenerative diseases through the use of neuronal differentiation or control of the microenvironment, traditional surgical transplantation methods like parenchymal or intravenous injection have limitations such as secondary injuries in the brain, infection, and low survival rate of stem cells in the target site. Focused ultrasound (FUS) treatment is an emerging modality for the treatment of brain diseases, including neurodegenerative disorders. The various biological effects of FUS treatment have been investigated; therefore, the goal is now to improve the delivery efficiency and function of MSCs by capitalizing on the advantages of FUS. In this study, we demonstrated that FUS increases MSC transplantation into brain tissue by >2-fold, and that this finding might be related to the activation of intercellular adhesion molecule-1 in endothelial and subendothelial cells and vascular adhesion molecule-1 in endothelial cells.

Principal Criteria for Evaluating the Quality, Safety and Efficacy of hMSC-Based Products in Clinical Practice: Current Approaches and Challenges

Human Mesenchymal Stem Cells (hMSCs) play an important role as new therapeutic alternatives in advanced therapies and regenerative medicine thanks to their regenerative and immunomodulatory properties, and ability to migrate to the exact area of injury. These properties have made hMSCs one of the more promising cellular active substances at present, particularly in terms of the development of new and innovative hMSC-based products. Currently, numerous clinical trials are being conducted to evaluate the therapeutic activity of hMSC-based products on specific targets. Given the rapidly growing number of hMSC clinical trials in recent years and the complexity of these products due to their cellular component characteristics and medicinal product status, there is a greater need to define more stringent, specific, and harmonized requirements to characterize the quality of the hMSCs and enhance the analysis of their safety and efficacy in final products to be administered to patients. These requirements should be implemented throughout the manufacturing process to guarantee the function and integrity of hMSCs and to ensure that the hMSC-based final product consistently meets its specifications across batches. This paper describes the principal phases involved in the design of the manufacturing process and updates the specific technical requirements needed to address the appropriate clinical use of hMSC-based products. The challenges and limitations to evaluating the safety, efficacy, and quality of hMSCs have been also reviewed and discussed.

Role of XIAP gene overexpressed bone marrow mesenchymal stem cells in the treatment of cerebral injury in rats with cerebral palsy

Background

This study is performed to investigate the effects of adenovirus-mediated X-linked inhibitor of apoptosis protein (XIAP) overexpressed bone marrow mesenchymal stem cells (BMSCs) on brain injury in rats with cerebral palsy (CP).

Methods

Rat’s BMSCs were cultured and identified. The XIAP gene of BMSCs was modified by adenovirus expression vector Ad-XIAP-GFP. The rat model of CP with ischemia and anoxia was established by ligating the left common carotid artery and anoxia for 2 h, and BMSCs were intracerebroventricularly injected to the modeled rats. The mRNA and protein expression of XIAP in brain tissue of rats in each group was detected by RT-qPCR and western blot analysis. The neurobehavioral situation, content of acetylcholine (Ach), activity of acetylcholinesterase (AchE), brain pathological injury, apoptosis of brain nerve cells and the activation of astrocytes in CP rats were determined via a series of assays.

Results

Rats with CP exhibited obvious abnormalities, increased Ach content, decreased AchE activity, obvious pathological damage, increased brain nerve cell apoptosis, as well as elevated activation of astrocyte. XIAP overexpressed BMSCs improved the neurobehavioral situation, decreased Ach content and increased AchE activity, attenuated brain pathological injury, inhibited apoptosis of brain nerve cells and the activation of astrocytes in CP rats.

Conclusion

Our study demonstrates that XIAP overexpressed BMSCs can inhibit the apoptosis of brain nerve cells and the activation of astrocytes, increase AchE activity, and inhibit Ach content, so as to lower the CP caused by cerebral ischemia and hypoxia in rats.

Comparison of different uncoated and starch-coated superparamagnetic iron oxide nanoparticles: Implications for stem cell tracking

However, labelling of stem cells using nanoparticles (NPs) for tracking purpose has been intensively investigated, the biosafety of these materials needs more clarification. Herein, different forms of iron oxide Fe₂O₃, Fe₃O₄, and Co_xNi_1-x Fe₂O₄ NPs either uncoated or starch-coated (ST-coated) were prepared. We successfully labelled adipose-derived stem cells (ASCs) using these NPs with the aid of lipofectamine as a transfection agent (TA). We then evaluated the effect of these NPs on stem cell proliferation, viability, migration and angiogenesis. Results showed that ASCs labelled with Fe₂O₃, Fe₃O₄, ST-Fe₂O₃ and ST-Fe₃O₄ did not show any significant difference in proliferation compared to that of TA-treated cells. Moreover, they have shown a protective effect against apoptosis. Conversely, Co_xNi_1-x Fe₂O₄ NPs caused a significant decrease in cell proliferation. Compared to that of the TA-treated cells, the migration capacity of cells labelled with Fe₂O₃, Fe₃O₄ and Co_xNi_1-xFe₂O₄ was significantly compromised. Interestingly, the ST-coated composites reversed this effect. Among the groups treated with different NPs, the angiogenic potential of the ASCs was most robust in the ST-Fe₂O₃-treated group. In conclusion, labelling ASCs with ST-Fe₂O₃ NPs enhanced cell migration and angiogenic potential and conferred higher resistance to apoptosis than labelling the cells with the other tested NPs.

Biomimetic polyetheretherketone microcarriers with specific surface topography and self-secreted extracellular matrix for large-scale cell expansion

Reusable microcarriers with appropriate surface topography, mechanical properties, as well as biological modification through decellularization facilitating repeated cell culture are crucial for tissue engineering applications. Herein, we report the preparation of topological polyetheretherketone (PEEK) microcarriers via gas-driven and solvent exchange method followed by hydrothermal treatment at high temperature and pressure. After hydrothermal treated for 8 h, the resulting topological PEEK microcarriers exhibit walnut-like surface topography and good sphericity as well as uniform size distribution of 350.24 ± 19.44 µm. And the average width between ravine-patterned surface of PEEK microcarriers is 780 ± 290 nm. After repeated steam sterilization by autoclaving for three times, topological PEEK microcarriers show nearly identical results compared with previous ones indicating strong tolerance to high temperature and pressure. This is a unique advantage for large-scale cell expansion and clinical applications. Moreover, PEEK microcarriers with special topography possess higher protein adsorption efficiency. In addition, the reutilization and biofunctionalization with repeated decellularization of topological PEEK microcarriers show highly beneficial for cell adhesion and proliferation. Therefore, our study is of great importance for new generation microcarriers with micro-and nano-scale surface feature for a broad application prospect in tissue engineering.

Membrane-encapsulated camouflaged nanomedicines in drug delivery

Owing to the limitations of conventional therapies, there has been an increasing need for nanomedicines for real-time diagnosis and effective treatment of life-threatening diseases. Despite the conceptual and technological success achieved by researchers worldwide, the complexities of biological systems, efficient engineering and formulation of monodispersed nanomedicines, inadequate information on bio–nano interactions, issues on health hazards, clinical trials and commercialization have set new challenges in biomedical research. This review highlights how the biological membrane improves the performance of nanomedicines in drug delivery. With the list of nanomedicines getting longer gradually to overcome the drawbacks of conventional therapeutics, it is important to concentrate on the interactions between nanostructures and living systems in order to improve the biocompatibility and therapeutic efficacy of functional nanomedicines.