Allogeneic administration of human umbilical cord-derived mesenchymal stem/stromal cells for bronchopulmonary dysplasia: preliminary outcomes in four Vietnamese infants

Safety, Efficacy and Bio-Distribution Analysis of Exosomes Derived From Human Umbilical Cord Mesenchymal Stem Cells for Effective Treatment of Bronchopulmonary Dysplasia by Intranasal Administration in Mice Model

Purpose

Exosomes (Exos) derived from human umbilical cord mesenchymal stem cells (hUC-MSCs) hold great potential for treating bronchopulmonary dysplasia (BPD); however, safety concerns and effects of intranasal administration remain unexplored. This study aimed to explore the safety of hUC-MSCs and Exos and to investigate the efficacy and bio-distribution of repeated intranasal Exos administration in neonatal BPD models.

Methods

Characteristics of hUC-MSCs and Exos were analyzed. A subcutaneous tumor formation assay using a single dose of hUC-MSCs or Exos was conducted in Crl:NU-Foxn1nu mice. Vital signs, biochemical indices, pathological alterations, and 18F-FDG microPET/CT analysis were examined. Pulmonary pathology, three-dimensional reconstructions, ultrastructural structures, in vivo and ex vivo bio-distribution imaging analyses, enzyme-linked immunoassay assays, and reverse transcription-quantitative polymerase chain reaction analyses of lung tissues were all documented following intranasal Exos administration.

Results

Characteristics of hUC-MSCs and Exos satisfied specifications. Crl:NU-Foxn1nu mice did not exhibit overt toxicity or carcinogenicity following a single dose of hUC-MSCs or Exos after 60 days of observation. Repeated intranasal Exos administration effectively alleviated pathological injuries, restored pulmonary ventilation in three-dimensional reconstruction, and recovered endothelial cell layer integrity in ultrastructural analysis. Exos steadily accumulated in lung tissues from postnatal day 1 to 14. Exos also interrupted the epithelial-mesenchymal transition and inflammation reactions in BPD models.

Conclusion

As a nanoscale, non-cellular therapy, intranasal administration of Exos was an effective, noninvasive treatment for BPD. This approach was free from toxic, tumorigenic risks and repaired alveolar damage while interrupting epithelial-mesenchymal transition and inflammation in neonatal mice with BPD.

Cell-based therapies in preclinical models of necrotizing enterocolitis: a systematic review and meta-analysis

Necrotizing enterocolitis (NEC) remains an incurable gut complication of prematurity with significant morbidity and mortality. Cell therapies, including mesenchymal stromal cells (MSCs), may be a promising treatment given their anti-inflammatory and regenerative potential. We assessed the effect of MSCs and other cell therapies (not classified as MSCs) on incidence, severity, and mortality in preclinical models of NEC. Bibliographic and gray literature searches yielded 17 371 records with 107 full-text articles assessed and ultimately 16 studies were included. These studies featured only rodents NEC models via combination of hyperosmolar feeds, hypoxia, hypothermia, or lipopolysaccharides. Ten studies used interventions with MSCs. Only 2 met the minimal criteria to define MSCs proposed by the International Society for Cell & Gene Therapy (ISCT). The overall risk of bias was assessed as high partly due to paucity of data with important gaps in reporting, reinforcing the importance of rigorous research framework, appropriate cell-therapy and outcome reporting in preclinical research. A reduction in the incidence of NEC (odds ratio [OR] 0.32, 95% CI [0.17, 0.62]), severe NEC (OR 0.30, 95% CI [0.18, 0.50]), and mortality (OR 0.30, 95% CI [0.16, 0.55]) was noted with MSCs treatment, seemingly more pronounced for ISCT-defined (ISCT+) MSCs. Amniotic fluid stem cells, neural stem cells, and placenta stem cells also showed a reduction in these measures. Given their accessibility (ie, umbilical cord) and proven safety profile in extremely preterm infants, our analysis provides a foundation for considering MSCs as promising candidate that requires further evaluation for the treatment of NEC.

Reinitiating lung development: a novel approach in the management of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is the predominant chronic lung disease in preterm infants, linked with various adverse long-term outcomes. Multiple prenatal and postnatal risk factors can impede lung development, leading to BPD. Current management of BPD relies heavily on pharmacotherapies and alterations in ventilatory strategies. However, these interventions only mitigate BPD symptoms without addressing underlying alveolar, vascular, structural, and functional deficiencies. Given the retarded lung development in infants with BPD and the limitations of existing modalities, new therapeutic approaches are imperative. The induced differentiation of stem/progenitor cells and the spatiotemporal expression patterns of growth factors associated with lung developmental processes are critical for lung development reactivation in BPD, which focuses on stimulating pulmonary vasculogenesis and alveolarization. This review summarizes the process of lung development and offers a comprehensive overview of advancements in therapies designed to reinitiate lung development in BPD. Furthermore, we assessed the potential of these therapies for maintaining lung homeostasis and effectively restoring pulmonary structure and function through stem/progenitor cells and growth factors, which have been widely researched.

Repeated intravenous doses of human umbilical cord-derived mesenchymal stromal cells for bronchopulmonary dysplasia: results of a phase 1 clinical trial with 2-year follow-up

BACKGROUND

Currently, there is a lack of effective treatments or preventive strategies for bronchopulmonary dysplasia (BPD). Pre-clinical studies with mesenchymal stromal cells (MSCs) have yielded encouraging results. The safety of administering repeated intravenous doses of umbilical cord tissue-derived mesenchymal stromal cells (UC-MSCs) has not yet been tested in extremely-low-gestational-age newborns (ELGANs).

AIMS

to test the safety and feasibility of administering three sequential intravenous doses of UC-MSCs every 7 days to ELGANs at risk of developing BPD.

METHODS

In this phase 1 clinical trial, we recruited ELGANs (birth weight ≤1250 g and ≤28 weeks in gestational age [GA]) who were on invasive mechanical ventilation (IMV) with FiO2 ≥ 0.3 at postnatal days 7-14. Three doses of 5 × 106/kg of UC-MSCs were intravenously administered at weekly intervals. Adverse effects and prematurity-related morbidities were recorded.

RESULTS

From April 2019 to July 2020, 10 patients were recruited with a mean GA of 25.2 ± 0.8 weeks and a mean birth weight of 659.8 ± 153.8 g. All patients received three intravenous UC-MSC doses. The first dose was administered at a mean of 16.6 ± 2.9 postnatal days. All patients were diagnosed with BPD. All patients were discharged from the hospital. No deaths or any serious adverse events related to the infusion of UC-MSCs were observed during administration, hospital stays or at 2-year follow-up.

CONCLUSIONS

The administration of repeated intravenous infusion of UC-MSCs in ELGANs at a high risk of developing BPD was feasible and safe in the short- and mid-term follow-up.

Progress in Research on Stem Cells in Neonatal Refractory Diseases

With the development and progress of medical technology, the survival rate of premature and low-birth-weight infants has increased, as has the incidence of a variety of neonatal diseases, such as hypoxic-ischemic encephalopathy, intraventricular hemorrhage, bronchopulmonary dysplasia, necrotizing enterocolitis, and retinopathy of prematurity. These diseases cause severe health conditions with poor prognoses, and existing control methods are ineffective for such diseases. Stem cells are a special type of cells with self-renewal and differentiation potential, and their mechanisms mainly include anti-inflammatory and anti-apoptotic properties, reducing oxidative stress, and boosting regeneration. Their paracrine effects can affect the microenvironment in which they survive, thereby affecting the biological characteristics of other cells. Due to their unique abilities, stem cells have been used in treating various diseases. Therefore, stem cell therapy may open up the possibility of treating such neonatal diseases. This review summarizes the research progress on stem cells and exosomes derived from stem cells in neonatal refractory diseases to provide new insights for most researchers and clinicians regarding future treatments. In addition, the current challenges and perspectives in stem cell therapy are discussed.

Innovations in cell therapy in pediatric diseases: a narrative review

Background and Objective

Stem cell therapy is a regenerative medicine modality that has the potential to decrease morbidity and mortality by promoting tissue regeneration or modulating the inflammatory response. An increase in the number of clinical trials investigating the efficacy and safety of stem cell therapy in pediatric diseases has led to advancements in this field. Currently, multiple sources and types of stem cells have been utilized in the treatment of pediatric diseases. This review aims to inform researchers and clinicians about preclinical and clinical stem cell therapy trials in pediatric patients. We discuss the different types of stem cells and the wide spectrum of stem cell therapy trials for pediatric diseases, with an emphasis on the outcomes and advancements in the field.

Methods

PubMed and clinicaltrials.gov databases were searched on October 28, 2022 using the following Medical Subject Headings (MeSH) terms "stem cell" or "stem cell therapy" with an age filter <18 years. Our search was limited to publications published between 2000 and 2022.

Key Content and Findings

Diverse sources of stem cells have different properties and mechanisms of action, which allow tailored application of stem cells according to the pathophysiology of the disease. Advancements in stem cell therapies for pediatric diseases have led to improvements in clinical outcomes in some pediatric diseases or in quality of life, such therapies represent a potential alternative to the current treatment modalities.

Conclusions

Stem cell therapy in pediatric diseases has shown promising results and outcomes. However, further studies focusing on the implementation and optimal treatment timeframe are needed. An increase in preclinical and clinical trials of stem cell therapy targeting pediatric patients is required to advance our therapeutic applications.

A Pilot Phase I Trial of Allogeneic Umbilical Cord Tissue-Derived Mesenchymal Stromal Cells in Neonates With Hypoxic-Ischemic Encephalopathy

Hypoxic ischemic encephalopathy (HIE) in neonates causes increased mortality and long-term morbidity in surviving babies. Hypothermia (HT) has improved outcomes, however, mortality remains high with ~half of surviving babies developing neurological impairment in their first years. We previously explored the use of autologous cord blood (CB) to determine if CB cells could lessen long-term damage to the brain. However, the feasibility of CB collection from sick neonates limited the utility of this approach. Allogeneic cord tissue mesenchymal stromal cells (hCT-MSC), cryopreserved and readily available, have been shown to ameliorate brain injury in animal models of HIE. We, therefore, conducted a pilot, phase I, clinical trial to test the safety and describe the preliminary efficacy of hCT-MSC in neonates with HIE. The study treated infants with moderate to severe HIE, treated with HT, with 1 or 2 doses of 2 million cells/kg/dose of hCT-MSC given intravenously. The babies were randomized to receive 1 or 2 doses with the first dose during HT and the second dose 2 months later. Babies were followed for survival and development with scoring of Bayley's at 12 postnatal months. Six neonates with moderate (4) or severe (2) HIE were enrolled. All received 1 dose of hCT-MSC during HT and 2 received a 2nd dose, 2 months later. hCT-MSC infusions were well tolerated although 5/6 babies developed low titer anti-HLA antibodies by 1 year of age. All babies survived, with average to low-average developmental assessment standard scores for ages between 12 and 17 postnatal months. Further study is warranted.

TITLE: New therapeutic approaches in pediatric diseases: Mesenchymal stromal cell and mesenchymal stromal cell-derived extracellular vesicles as new drugs

Mesenchymal Stromal Cell (MSC) clinical applications have been widely reported and their therapeutic potential has been documented in several diseases. MSCs can be isolated from several human tissues and easily expanded in vitro, they are able to differentiate in a variety of cell lineages, and they are known to interact with most immunological cells, showing immunosuppressive and tissue repair properties. Their therapeutic efficacy is closely associated with the release of bioactive molecules, namely Extracellular Vesicles (EVs), effective as their parental cells. EVs isolated from MSCs act by fusing with target cell membrane and releasing their content, showing a great potential for the treatment of injured tissues and organs, and for the modulation of the host immune system. EV-based therapies provide, as major advantages, the possibility to cross the epithelium and blood barrier and their activity is not influenced by the surrounding environment. In the present review, we deal with pre-clinical reports and clinical trials to provide data in support of MSC and EV clinical efficacy with particular focus on neonatal and pediatric diseases. Considering pre-clinical and clinical data so far available, it is likely that cell-based and cell-free therapies could become an important therapeutic approach for the treatment of several pediatric diseases.

Phase I trial of human umbilical cord-derived mesenchymal stem cells for treatment of severe bronchopulmonary dysplasia

Severe bronchopulmonary dysplasia (BPD) is a chronic lung disorder that primarily affects premature babies with extremely low birth weight and involves in multiple organ system; no effective pharmacotherapy for this disease exists, and mortality remains high. Based on the evidence from previous preclinical studies and phase I clinical trials, this study aims to test the safety of intravenous application of a single dose of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in patients with severe BPD. The Mesenchymal Stem cells for Bronchopulmonary Dysplasia Treatment (MSBDT) trial is a single center, open-label, dose-escalation phase I clinical trial. Severe BPD patients were enrolled in Children Hospital of Chongqing Medical University, Chongqing, China. The first six patients were treated with low-dose hUC-MSCs (1 × 106 cells/kg) and the next seven patients were treated with high-dose hUC-MSCs (5 × 106 cells/kg). This study is registered with ClinicalTrials.gov, number NCT03558334. No prespecified infusion-associated adverse events, immediate complication, respiratory or cardiovascular compromise were observed during infusion and 24 h after infusion. No significant changes in safety laboratory values were observed. One death event occurred in the low-dose group on study day 10, and one death event occurred in the high-dose group on study day 24, while, after review in detail, the two cases are not believed to be infusion-associated events. In conclusion, intravenous application of a single dose of hUC-MSCs was tolerated in thirteen patients with severe BPD.

Safety and Efficacy of Mesenchymal Stem Cells for the Treatment of Evolving and Established Bronchopulmonary Dysplasia: A Systematic Literature Review

Bronchopulmonary dysplasia (BPD) is a frequent sequela of modern medicine when infants are born prematurely. Currently, there is no single treatment or combination of treatments to prevent or fully treat BPD. Mesenchymal stem cells (MSCs) have promising properties that could aid in the reversal of lung injury, as seen in patients with BPD. This study reviews the available evidence regarding the safety and efficacy of the use of MSCs for the treatment of evolving and established BPD. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We found eight studies that fulfilled the inclusion and exclusion criteria. While all studies proved the safety and efficacy of MSCs administered intravenously and intratracheally, the only available randomized controlled trial (RCT) failed to demonstrate the benefit of MSC administration in the early treatment of BPD. The remaining studies varied between phase I clinical trials and case reports, but all seemed to show some evidence that MSCs may be of benefit in the late treatment of established BPD. Considering some of the studies have less evidence, early treatment to prevent lung fibrosis may be more successful, particularly in the younger gestational ages where lung development is more immature, and research should focus on this.

Model of Liver Fibrosis Induction by Thioacetamide in Rats for Regenerative Therapy Studies

Hepatic fibrosis is caused by chronic injury due to toxic, infectious, or metabolic causes, and it may progress to cirrhosis and hepatocellular carcinoma. There is currently no antifibrotic therapy authorized for human use; however, there are promising studies using cell therapies. There are also no animal models that exactly reproduce human liver fibrosis that can be used to better understand the mechanisms of its regression and identify new targets for treatment and therapeutic approaches. On the other hand, mesenchymal stem cells (MSC) have experimentally demonstrated fibrosis regression effects, but it is necessary to have an animal model of advanced liver fibrosis to evaluate the effect of these cells. The aim of this work was to establish a protocol for the induction of advanced liver fibrosis in rats using thioacetamide (TAA), which will allow us to perform trials using MSC as a possible therapy for fibrosis regression. For this purpose, we selected 24 female rats and grouped them into three experimental groups: the control group (G-I) without treatment and groups II (G-II) and III (G-III) that received TAA by intraperitoneal injection for 24 weeks. Then, 1 × 106/kg adipose mesenchymal stem cells (ASCs) were infused intravenously. Groups G-I and G-II were sacrificed 7 days after the last dose of ASC, and G-III was sacrificed 8 weeks after the last ASC infusion, all with xylazine/ketamine (40 mg/kg). The protocol used in this work established a model of advanced hepatic fibrosis as corroborated by METAVIR tests of the histological lesions; by the high levels of the markers α-SMA, CD68, and collagen type I; by functional alterations due to elevated markers of the hepatic lesions; and by alterations of the leukocytes, lymphocytes, and platelets. Finally, transplanted cells in the fibrous liver were detected. We conclude that TAA applied using the protocol introduced in this study induces a good model of advanced liver fibrosis in rats.

Stem cell-based therapy for human diseases

Recent advancements in stem cell technology open a new door for patients suffering from diseases and disorders that have yet to be treated. Stem cell-based therapy, including human pluripotent stem cells (hPSCs) and multipotent mesenchymal stem cells (MSCs), has recently emerged as a key player in regenerative medicine. hPSCs are defined as self-renewable cell types conferring the ability to differentiate into various cellular phenotypes of the human body, including three germ layers. MSCs are multipotent progenitor cells possessing self-renewal ability (limited in vitro) and differentiation potential into mesenchymal lineages, according to the International Society for Cell and Gene Therapy (ISCT). This review provides an update on recent clinical applications using either hPSCs or MSCs derived from bone marrow (BM), adipose tissue (AT), or the umbilical cord (UC) for the treatment of human diseases, including neurological disorders, pulmonary dysfunctions, metabolic/endocrine-related diseases, reproductive disorders, skin burns, and cardiovascular conditions. Moreover, we discuss our own clinical trial experiences on targeted therapies using MSCs in a clinical setting, and we propose and discuss the MSC tissue origin concept and how MSC origin may contribute to the role of MSCs in downstream applications, with the ultimate objective of facilitating translational research in regenerative medicine into clinical applications. The mechanisms discussed here support the proposed hypothesis that BM-MSCs are potentially good candidates for brain and spinal cord injury treatment, AT-MSCs are potentially good candidates for reproductive disorder treatment and skin regeneration, and UC-MSCs are potentially good candidates for pulmonary disease and acute respiratory distress syndrome treatment.

Recent research on the mechanism of mesenchymal stem cells in the treatment of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease due to impaired pulmonary development and is one of the main causes of respiratory failure in preterm infants. Preterm infants with BPD have significantly higher complication and mortality rates than those without BPD. At present, comprehensive management is the main intervention method for BPD, including reasonable respiratory and circulatory support, appropriate enteral nutrition and parenteral nutrition, application of caffeine/glucocorticoids/surfactants, and out-of-hospital management after discharge. The continuous advances in stem cell medicine in recent years provide new ideas for the treatment of BPD. Various pre-clinical trials have confirmed that stem cell therapy can effectively prevent lung injury and promote lung growth and damage repair. This article performs a comprehensive analysis of the mechanism of mesenchymal stem cells in the treatment of BPD, so as to provide a basis for clinical applications.

Human Umbilical Cord Mesenchymal Stem Cells for Severe Neurological Sequelae due to Anti-N-Methyl-d-Aspartate Receptor Encephalitis: First Case Report

Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is caused by altered patient immune reactions. This study reports the first patient with severe neurologic sequelae after NMDA receptor encephalitis treated with allogeneic umbilical cord-derived mesenchymal stem/stromal cells (UC-MSCs). A 5-year-old girl was diagnosed with NMDA receptor encephalitis and treated with immunosuppressive medicaments and intravenous immunoglobulin (IVIG). Despite intensive therapy, the patient's condition worsened so that allogenic UC-MSC therapy was contemplated. The patient received three intrathecal infusions of xeno- and serum-free cultured UC-MSCs at a dose of 10⁶ cells/kg. At baseline and after each UC-MSC administration, the patient was examined by the German Coma Recovery Scale (CRS), the Gross Motor Function Classification System (GMFCS), the Gross Motor Function Measure-88 (GMFM-88), the Manual Ability Classification System (MACS), the Modified Ashworth Scale, and the Denver II test. Before cell therapy, she was in a permanent vegetative state with diffuse cerebral atrophy. Her cognition and motor functions improved progressively after three UC-MSC infusions. At the last visit, she was capable of walking, writing, and counting numbers. Control of urinary and bowel functions was completely recovered. Cerebral atrophy was reduced on brain magnetic resonance imaging (MRI). Overall, the outcomes of this patient suggest a potential cell therapy for autoimmune encephalitis and its neurological consequences.

Mesenchymal Stem Cell-Derived Extracellular Vesicles for the Treatment of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common chronic respiratory disease in premature infants. However, there is a lack of effective treatment. Mesenchymal stromal cells derived extracellular vesicles (MSC-EVs), as nano- and micron-sized heterogeneous vesicles secreted by MSCs, are the main medium for information exchange between MSCs and injured tissue and organ, playing an important role in repairing tissue and organ injury. EVs include exosomes, microvesicles and so on. They are rich with various proteins, nucleic acids, and lipids. Now, EVs are considered as a new way of cell-to-cell communication. EVs mainly induce regeneration and therapeutic effects in different tissues and organs through the biomolecules they carry. The surface membrane protein or loaded protein and nucleic acid molecules carried by EVs, can activate the signal transduction of target cells and regulate the biological behavior of target cells after binding and cell internalization. MSC-EVs can promote the development of pulmonary vessels and alveoli and reduce pulmonary hypertension (PH) and inflammation and play an important role in the repair of lung injury in BPD. The regeneration potential of MSC-EVs is mainly due to the regulation of cell proliferation, survival, migration, differentiation, angiogenesis, immunoregulation, anti-inflammatory, mitochondrial activity and oxidative stress. As a new type of cell-free therapy, MSC-EVs have non-immunogenic, and are small in size and go deep into most tissues. What's more, it has good biological stability and can be modified and loaded with drugs of interest. Obviously, MSC-EVs have a good application prospect in the treatment of lung injury and BPD. However, there are still many challenges to make MSC-EVs really enter clinical application.

Mesenchymal stem cell-derived extracellular vesicles suppress hyperoxia-induced transdifferentiation of rat alveolar type 2 epithelial cells

Bronchopulmonary dysplasia (BPD) remains the most important respiratory morbidity of preterm infants with few effective preventive strategies. Administration of mesenchymal stem cells (MSC) was considered effective to prevent BPD via paracrine extracellular vesicles (EVs), while appropriate regimens of MSC-EVs and the mechanism remain unclear. Therefore, we established a hyperoxia-induced rat BPD model, and examined the effect of early intraperitoneal MSC-EVs with different doses on BPD. We found that MSC-EVs ameliorated hyperoxia-induced lung injury in a dose-dependent manner, and high dose MSC-EVs ameliorated alveolar simplification and fibrosis. Also, MSC-EVs showed its beneficial effects on vascular growth and pulmonary hypertension. Primary AT2 cells were observed to transdifferentiate into AT1 cells when exposure to hyperoxia in vitro. Administration of MSC-EVs at the first-day culture significantly delayed the transdifferentiation of AT2 cells induced by hyperoxia. We further found that exposure to hyperoxia led to elevated expression of WNT5a mRNA and protein, a key agent in AT2 transdifferentiation, while MSC-EVs administration decreased it. Further study is warranted that MSC-EVs may delay the transdifferentiation of AT2 cells via WNT5a. These studies provide key preclinical evidence of MSC-EVs therapeutics on BPD and highlight the effect of MSC-EVs on suppressing the transdifferentiation of AT2 cells and its possible mechanism through downregulation of WNT5a.

Clinically relevant preservation conditions for mesenchymal stem/stromal cells derived from perinatal and adult tissue sources

The interplay between mesenchymal stem/stromal cells (MSCs) and preservation conditions is critical to maintain the viability and functionality of these cells before administration. We observed that Ringer lactate (RL) maintained high viability of bone marrow–derived MSCs for up to 72 h at room temperature (18°C–22°C), whereas adipose‐derived and umbilical cord‐derived MSCs showed the highest viability for 72 h at a cold temperature (4°C–8°C). These cells maintained their adherence ability with an improved recovery rate and metabolic profiles (glycolysis and mitochondrial respiration) similar to those of freshly harvested cells. Growth factor and cytokine analyses revealed that the preserved cells released substantial amounts of leukaemia inhibitory factors (LIFs), hepatocyte growth factor (HGF) and vascular endothelial growth factor‐A (VEGF‐A), as well as multiple cytokines (eg IL‐4, IL‐6, IL‐8, MPC‐1 and TNF‐α). Our data provide the simplest clinically relevant preservation conditions that maintain the viability, stemness and functionality of MSCs from perinatal and adult tissue sources.

Human Adipose-Derived Mesenchymal Stromal Cells Exhibit High HLA-DR Levels and Altered Cellular Characteristics under a Xeno-free and Serum-free Condition

Background

We have observed an increased expression of negative markers in some clinical-grade, xeno- and serum-free cultured adipose-derived mesenchymal stem/stromal cell (ADMSC) samples. It gave rise to concern that xeno- and serum-free conditions might have unexpected effects on human ADMSCs. This study aims to test this hypothesis for two xeno- and serum-free media, PowerStem MSC1 media (PS) and StemMACS MSC Expansion Media (SM), that support the in vitro expansion of ADMSCs.

Methods

We investigated the expression of negative markers in 42 clinical-grade ADMSC samples expanded in PS. Next, we cultured ADMSCs from seven donors in PS and SM and examined their growth and colony-forming ability, surface marker expression, differentiation, cell cycle and senescence, as well as genetic stability of two passages representing an early and late passage for therapeutic MSCs.

Results

15 of 42 clinical-grade PS-expanded ADMSC samples showed an increased expression of negative markers ranging from 2.73% to 34.24%, which positively correlated with the age of donors. This rise of negative markers was related to an upregulation of Human Leukocyte Antigen – DR (HLA-DR). In addition, the PS-cultured cells presented decreased growth ability, lower frequencies of cells in S/G2/M phases, and increased ß-galactosidase activity in passage 7 suggesting their senescent feature compared to those grown in SM. Although MSCs of both PS and SM cultures were capable of multilineage differentiation, the PS-cultured cells demonstrated chromosomal abnormalities in passage 7 compared to the normal karyotype of their SM counterparts.

Conclusions

These findings suggest that the SM media is more suitable for the expansion of therapeutic ADMSCs than PS. The study also hints a change of ADMSC features at more advanced passages and with increased donor’s age. Thus, it emphasizes the necessity to cover these aspects in the quality control of therapeutic MSC products.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12015-021-10242-7.

Current Status and Future Prospects of Perinatal Stem Cells

The placenta is a temporary organ that is discarded after birth and is one of the most promising sources of various cells and tissues for use in regenerative medicine and tissue engineering, both in experimental and clinical settings. The placenta has unique, intrinsic features because it plays many roles during gestation: it is formed by cells from two individuals (mother and fetus), contributes to the development and growth of an allogeneic fetus, and has two independent and interacting circulatory systems. Different stem and progenitor cell types can be isolated from the different perinatal tissues making them particularly interesting candidates for use in cell therapy and regenerative medicine. The primary source of perinatal stem cells is cord blood. Cord blood has been a well-known source of hematopoietic stem/progenitor cells since 1974. Biobanked cord blood has been used to treat different hematological and immunological disorders for over 30 years. Other perinatal tissues that are routinely discarded as medical waste contain non-hematopoietic cells with potential therapeutic value. Indeed, in advanced perinatal cell therapy trials, mesenchymal stromal cells are the most commonly used. Here, we review one by one the different perinatal tissues and the different perinatal stem cells isolated with their phenotypical characteristics and the preclinical uses of these cells in numerous pathologies. An overview of clinical applications of perinatal derived cells is also described with special emphasis on the clinical trials being carried out to treat COVID19 pneumonia. Furthermore, we describe the use of new technologies in the field of perinatal stem cells and the future directions and challenges of this fascinating and rapidly progressing field of perinatal cells and regenerative medicine.