Placenta-derived Stem Cells Research Articles

Biosponge-Encased Placental Stem Cells for Volumetric Muscle Loss Repair.

Objective: Volumetric muscle loss (VML) leads to permanent muscle mass and functional impairments. While mesenchymal stromal cells (MSCs) and their secreted factors can aid muscle regeneration, MSCs exhibit limited persistence in injured tissue post-transplantation. Human placental-derived stem cells (hPDSCs), sharing surface markers with MSCs, demonstrate superior regenerative potential due to their fetal origin. Previously, a biosponge (BS) scaffold was shown to augment muscle regeneration post-VML. This study aims to coapply BS therapy and hPDSCs to further enhance muscle recovery following VML. Approach: A VML defect was created by removing ∼20% of the tibialis anterior muscle mass in male Lewis rats. Injured muscles were either left untreated or treated with BS or BS-encapsulated hPDSCs cultured under normoxic or hypoxic conditions. On day 28 postinjury, peak isometric torque was measured, and the muscle was harvested for analysis. Results: BS encapsulated hPDSCs subjected to hypoxic preconditioning persisted in larger quantities and enhanced muscle mass at day 28 postinjury. BS encapsulated hPDSCs cultured under normoxic or hypoxic conditions increased small myofibers (<500 µm2) percentage, MyoD protein expression, and both pro- and anti-inflammatory macrophage marker expression. BS encapsulated hPDSCs also reduced fibrosis and BS remodeling rate. Innovation: This study is the first to examine the therapeutic effects of hPDSCs in a rat VML model. A BS carrier and hypoxic preconditioning were investigated to mitigate low cell survival postimplantation. Conclusion: hPDSCs augment the regenerative effect of BS. Combining hPDSCs and BS emerges as a promising strategy worthy of further investigation.

Metalloproteinase’s Activity of Two Placenta-Derived Stem Cells Lines from a Donor Differing in the Adipogenic Differentiation Potential and Nature of Replicative Senescense

A long-term cultivation of 2 lines of human MSCs isolated from different sites of placenta was carried out. The MSC-PL-1 cell line is characterized by premature replicative senescence (RS) compared to the MSC-PL-2 line. During the induction of adipogenic differentiation (AD), it was shown that AD does not occur at early and late passages in cells of MSC-PL-1 line unlike cells of the MSC-PL-2 line. Comparative analysis of the activities of matrix metalloproteinases (MMP-1, -2 and -9) in the process of RS of these cell lines indicates interlinear differences. So, during RS in MSC-PL-2 cells the activity of MMP-2 and -1 decreases, and MMP-9 does not change, and in MSC-PL-1 cells with premature RS the activity of MMP-9 and -1 increases, while activity of MMP-2 decreases. The analysis of MMP -1 and -2 activities during the process of adipogenic differentiation in the MSC-PL-2 line at the early 6th passage showed a number of differences between the activity levels of these MMPs during 21 days, but they all showed the same wave-like manner of changes. The activity of MMP-9 had a different character of changes during the 21 days of differentiation. The same pattern of changes took place at the late 16th passage in same 3 MMP during 21 days of differentiation. Since there is no adipogenic differentiation in the MSC-PL-1 line, we analized the activities of MMP -1, -2 and -9 during cultivation in induction medium for 21 days in the early 6th and late 13th passages. There were changes in the activity of all MMPs in both variants, buy they were not synchronous. In general, there was a significant decrease in the activity of all 3 MMP on the 13th passage compared to the 6th passage. The obtained results indicate the participation of MMPs in a wide range of cellular processes.

Human placenta/umbilical cord derivatives in regenerative medicine - Prospects and challenges.

The human placenta and umbilical cord, natural birth biowaste, are a housing unit for numerous bioactive macromolecules, growth factors, collagen and GAGs, with an array of high-quality stem cells. MSCs isolated from the human placenta and umbilical cord are utilized in both research and medical applications due to their sustainable sourcing, high viability, multipotent lineage and potency. They present an unprecedented opportunity in the tissue engineering, biomedical and biotechnology fields with minimal ethical constraints and nominal cost. Considering the world population and daily birth rates, with appropriate utilization and management, they could resolve the MSC shortage in the global stem cell therapy market and present biomedical waste disposal. A considerable number of clinical trials are presently underway where placenta-derived stem cells have been administered for different pathologies. Since the umbilical cord and placenta's primary function is to sustain the fetus until delivery, it has an ample supply of nutrients, proteins and essential factors necessary to assist cell viability and proliferation. Present research and medical applications include the fabrication of ECM-based nanofibers, disease models, micro-tissue, hybrid models and artificial implants. Future utilization of birthing biomedical waste in medical engineering and research will provide a rich and sustainable source of stem cells and extracellular matrix for enhanced biocompatibility and regeneration.

Heat-Induced Proteotoxic Stress Response in Placenta-Derived Stem Cells (PDSCs) Is Mediated through HSPA1A and HSPA1B with a Potential Higher Role for HSPA1B.

Placenta-derived stem cells (PDSCs), due to unique traits such as mesenchymal and embryonic characteristics and the absence of ethical constraints, are in a clinically and therapeutically advantageous position. To aid in stemness maintenance, counter pathophysiological stresses, and withstand post-differentiation challenges, stem cells require elevated protein synthesis and consequently augmented proteostasis. Stem cells exhibit source-specific proteostasis traits, making it imperative to study them individually from different sources. These studies have implications for understanding stem cell biology and exploitation in the augmentation of therapeutic applications. Here, we aim to identify the primary determinants of proteotoxic stress response in PDSCs. We generated heat-induced dose-responsive proteotoxic stress models of three stem cell types: placental origin cells, the placenta-derived mesenchymal stem cells (pMSCs), maternal origin cells, the decidua parietalis mesenchymal stem cells (DPMSCs), and the maternal–fetal interface cells, decidua basalis mesenchymal stem cells (DBMSCs), and measured stress induction through biochemical and cell proliferation assays. RT-PCR array analysis of 84 genes involved in protein folding and protein quality control led to the identification of Hsp70 members HSPA1A and HSPA1B as the prominent ones among 17 significantly expressed genes and with further analysis at the protein level through Western blotting. A kinetic analysis of HSPA1A and HSPA1B gene and protein expression allowed a time series evaluation of stress response. As identified by protein expression, an active stress response is in play even at 24 h. More prominent differences in expression between the two homologs are detected at the translational level, alluding to a potential higher requirement for HSPA1B during proteotoxic stress response in PDSCs.

A comparative study of pathogen inactivation technologies in human platelet lysate and its optimal efficiency in human placenta-derived stem cells culture

BackgroundPathogen inactivation (PI) is necessary for the pooled components derived from a biological source. Recently, the use of human platelet lysate (hPL) has increased in the cell manufacturing process as a xeno-free substitute for Fetal Bovine Serum (FBS). Therefore, an effective PI process to produce a pathogen-free hPL with the optimal efficiency in the manufacturing of cell therapy products is a vital requirement. Study design and methodsTo evaluate the efficacy of gamma irradiation and riboflavin/ultraviolet light (RB/UV) as PI methods for hPL, the reduction factor (RF) of titer of model viruses and bacteria were examined. Furthermore, the effect of different PI methods on the hPL performance was evaluated by the in vitro expansion of human placenta-derived mesenchymal stem cells (PLMSCs). To compare different study groups, the growth kinetic, immunophenotype, colony formation, and differentiation capacity (osteogenic and adipogenic) of PLMSCs were examined. In addition, the concentration of growth factors was assayed in each study group. ResultsAchievement to the RF more than 5 log10 for all pathogens, showed the effectiveness of two PI methods. In comparison with the other study groups, the dose of 45 kGy gamma irradiation considerably decreased the growth factor level of the hPL. It also showed a significant adverse effect on PLMSCs growth kinetics. The dose of 30 KGy gamma irradiation and RB/UV demonstrated a favorable effect on different assays of the in vitro expanded PLMSCs. ConclusionThe 30 KGy gamma irradiation and RB/UV were effective in the RF of the viral and bacterial models of the contaminated hPL. The efficacy of these PI-hPLs for PLMSCs expansion was preserved. To increase the safety of cell therapy products, PI methods should be considered for the hPL preparations.

Downregulated Calcium-Binding Protein S100A16 and HSP27 in Placenta-Derived Multipotent Cells Induce Functional Astrocyte Differentiation

Little is known about genes that induce stem cells differentiation into astrocytes. We previously described that heat shock protein 27 (HSP27) downregulation is directly related to neural differentiation under chemical induction in placenta-derived multipotent stem cells (PDMCs). Using this neural differentiation cell model, we cross-compared transcriptomic and proteomic data and selected 26 candidate genes with the same expression trends in both omics analyses. Those genes were further compared with a transcriptomic database derived from Alzheimer’s disease (AD). Eighteen out of 26 candidates showed opposite expression trends between our data and the AD database. The mRNA and protein expression levels of those candidates showed downregulation of HSP27, S100 calcium-binding protein A16 (S100A16) and two other genes in our neural differentiation cell model. Silencing these four genes with various combinations showed that co-silencing HSP27 and S100A16 has stronger effects than other combinations for astrocyte differentiation. The induced astrocyte showed typical astrocytic star-shape and developed with ramified, stringy and filamentous processes as well as differentiated endfoot structures. Also, some of them connected with each other and formed continuous network. Immunofluorescence quantification of various neural markers indicated that HSP27 and S100A16 downregulation mainly drive PDMCs differentiation into astrocytes. Immunofluorescence and confocal microscopic images showed the classical star-like shape morphology and co-expression of crucial astrocyte markers in induced astrocytes, while electrophysiology and Ca2+ influx examination further confirmed their functional characteristics. In conclusion, co-silencing of S100A16 and HSP27 without chemical induction leads to PDMCs differentiation into functional astrocytes.Graphical abstract

A Review of Placenta and Umbilical Cord-Derived Stem Cells and the Immunomodulatory Basis of Their Therapeutic Potential in Bronchopulmonary Dysplasia.

Bronchopulmonary dysplasia (BPD) is a devastating lung disorder of preterm infants as a result of an aberrant reparative response following exposures to various antenatal and postnatal insults. Despite sophisticated medical treatment in this modern era, the incidence of BPD remains unabated. The current strategies to prevent and treat BPD have met with limited success. The emergence of stem cell therapy may be a potential breakthrough in mitigating this complex chronic lung disorder. Over the last two decades, the human placenta and umbilical cord have gained increasing attention as a highly potential source of stem cells. Placenta-derived stem cells (PDSCs) and umbilical cord-derived stem cells (UCDSCs) display several advantages such as immune tolerance and are generally devoid of ethical constraints, in addition to their stemness qualities. They possess the characteristics of both embryonic and mesenchymal stromal/stem cells. Recently, there are many preclinical studies investigating the use of these cells as therapeutic agents in neonatal disease models for clinical applications. In this review, we describe the preclinical and clinical studies using PDSCs and UCDSCs as treatment in animal models of BPD. The source of these stem cells, routes of administration, and effects on immunomodulation, inflammation and regeneration in the injured lung are also discussed. Lastly, a brief description summarized the completed and ongoing clinical trials using PDSCs and UCDSCs as therapeutic agents in preventing or treating BPD. Due to the complexity of BPD, the development of a safe and efficient therapeutic agent remains a major challenge to both clinicians and researchers.

Cell-based treatment for perinatal hypoxic-ischemic encephalopathy.

Hypoxic-ischemic encephalopathy (HIE) is a major cause of acute neonatal brain injury and can lead to disabling long-term neurological complications. Treatment for HIE is limited to supportive care and hypothermia within 6 h injury which is reserved for full-term infants. Preclinical studies suggest the potential for cell-based therapies as effective treatments for HIE. Some clinical trials using umbilical cord blood cells, placenta-derived stem cells, mesenchymal stem cells (MSCs), and others have yielded promising results though more studies are needed to optimize protocols and multi-center trials are needed to prove safety and efficacy. To date, the therapeutic effects of most cell-based therapies are hypothesized to stem from the bystander effect of donor cells. Transplantation of stem cells attenuate the aberrant inflammation cascade following HIE and provide a more ideal environment for endogenous neurogenesis and repair. Recently, a subset of MSCs, the multilineage-differentiating stress-enduring (Muse) cells have shown to treat HIE and other models of neurologic diseases by replacing dead or ischemic cells and have reached clinical trials. In this review, we examine the different cell sources used in clinical trials and evaluate the underlying mechanism behind their therapeutic effects. Three databases–PubMed, Web of Science, and ClinicalTrials.gov–were used to review preclinical and clinical experimental treatments for HIE.

Human placenta-derived stem cells - recent findings based on the molecular science

Abstract The human placenta is a complex, multifunctional transient fetomaternal organ. The placenta is composed of the maternal decidua basalis and its fetal part, consisting of the mesenchymal and trophoblast cell lineages. Both the placenta and the amniotic membranes are abundant in readily available placenta-derived mesenchymal stem cells (PD-MSCs). The clinical application of the PD-MSCs opens new perspectives for regenerative medicine and the treatment of various degenerative disorders. Their properties depend on their paracrine activity – the secretion of the anti-inflammatory cytokines and specific exosomes. In contrast to the PD-MSCs, the trophoblast stem cells (TSCs) are much more elusive. They can only be isolated from the blastocyst-stage embryos or the first-trimester placental tissue, making that procedure quite demanding. Also, other cultures require specific, strictly controlled conditions. TSCs may be potentially used as an in vitro model of various placental pathologies, facilitating the elucidation of their mysterious pathogenesis and creating the environment for testing the new drug efficiency. Nonetheless, it is unlikely that they could be ever implemented as a part of novel cellular therapeutic strategies in humans. Running title: Current knowledge on the placental stem cells

Trophoblast Stem-Cell-Derived Exosomes Improve Doxorubicin-Induced Dilated Cardiomyopathy by Modulating the let-7i/YAP Pathway

Trophoblast stem cells (TSCs) have been confirmed to play a cardioprotective role in heart failure. However, whether TSC-derived exosomes (TSC-exos) can protect against cardiac injury remains unclear. In the present study, TSC-exos were isolated from the supernatant of TSCs using the ultracentrifugation method and characterized by transmission electron microscopy and western blotting. Utilizing the public Gene Expression Omnibus (GEO) database, we found that let-7i and Yes-associated protein 1 (YAP) could participate in the development of heart failure. In vitro, AC16 cardiomyocytes subjected to doxorubicin (DOX) were treated with TSC-exos or let-7i mimic. Flow cytometry showed that TSC-exos and let-7i both decreased cardiomyocyte apoptosis. In vivo, mice that were intraperitoneally injected into DOX received either PBS, TSC-exos, or AAV9-let7iup for let-7i overexpression. Mice receiving TSC-exos and AAV9-let7iup showed improved cardiac function and decreased inflammatory responses, accompanied by downregulated YAP signaling. Mechanistically, TSC-exos could transfer let-7i to cardiomyocytes and silence the YAP signaling pathway. In conclusion, TSC-exos could alleviate DOX-induced cardiac injury via the let-7i/YAP pathway, which sheds new light on the application of TSC-exos as a potential therapeutic tool for heart failure.

Hypoxia-Preconditioned Placenta-Derived Mesenchymal Stem Cells Rescue Optic Nerve Axons Via Differential Roles of Vascular Endothelial Growth Factor in an Optic Nerve Compression Animal Model

Human placenta-derived stem cells (hPSCs) with the therapeutic potential to recover from optic nerve injury have been reported. We have recently demonstrated that hPSCs have protective abilities against hypoxic damage. To improve the capacity of hPSCs, we established a hypoxia-preconditioned strain (HPPCs) using a hypoxic chamber. The hPSCs were exposed to short-term hypoxic conditions of 2.2% O2 and 5.5% CO2. We also performed in vivo experiments to demonstrate the recovery effects of HPPCs using an optic nerve injury rat model. Naïve hPSCs (and HPPCs) were injected into the optic nerve. After 1, 2, or 4weeks, we analyzed changes in target proteins in the optic nerve tissues. In the retina, GAP43 expression was higher in both groups of naïve hPSCs and HPPCs versus sham controls. Two weeks after injection, all hPSC-injected groups showed recovery of tuj1 expression in damaged retinas. We also determined GFAP expression in retinas using the same model. In optic nerve tissues, HIF-1α levels were significantly lower in the HPPC-injected group 1week after injury, and Thy-1 levels were higher in the hPSC-injected group at 4weeks. There was also an enhanced recovery of Thy-1 expression after HPPC injection. In addition, R28 cells exposed to hypoxic conditions showed improved viability through enhanced recovery of HPPCs than naïve hPSCs. VEGF protein was a mediator in the recovery pathway via upregulation of target proteins regulated by HPPCs. Our results suggest that HPPCs may be candidates for cell therapy for the treatment of traumatic optic nerve injury.

Placenta derived stem cells for acute kidney injury treatment in a xenogeneic preclinical model

Background & Aim Acute kidney injury (AKI) is a life-threatening postoperative complication, affecting 10-30% of treated patients and characterized by the damage to the proximal tubular cells, thereby markedly impairing renal function.1,2,3 15% of patients develop chronic kidney disease (CKD) and fibrosis, eventually managed by hemodialysis and kidney transplantation.4 Mesenchymal stem cells have been shown to possess anti-inflammatory and immunomodulatory properties and be able to aid in tissue repair.5 A link between AKI and CKD has been established and the optimal treatment approach to reduce the high unmet medical need and an economical burden is still being researched.6 Placenta-derived mesenchymal stem cells (PSCs) may be a viable approach to treat AKI and prevent subsequent CKD development. Methods, Results & Conclusion M.: PSCs have been isolated using GMP grade materials, cultivated for three weeks and characterized by yield, viability, flow cytometry and potency in vitro. Wistar rats (8-12 wk) underwent preclinical ischemia-reperfusion injury (IRI). Two experimental groups received treatment. Experimental group (Index) received 3 × 105 of PSCs in the corticomedullar region of each kidney. Control group (Control) received PBS vehicle solution. Survival analysis was carried out till day 7. Urine and blood serum samples were collected on day 0, 3 and 7 and analysed for urine volume/24hrs., protein, creatinine, urea, Na+ and K+. Histological kidney analysis on days 3 and 7 for evaluation of tubular necrosis. R. PSCs had a consistent yield, viability, MSCs markers expression and suppressed proliferation of T cells. Survival rate improved – 100% (Index) vs. 75% (Control). Serum urea and K+ was reduced in index group on day 7 (p Serum creatinine was 1.9 and 1.6 times lower in index group on days 3 and 7, respectively. Na+ was similarly lower after 7 days after PSCs injection. Extensive acute tubular necrosis (ATN) with broad coagulative tubular epithelial necrosis was evident after 3 days in the Control group. Variable extent of ATN without significant coagulative necrosis was observed after 3 and 7 days of Index group. C. Placental derived stem cells have the potential to prevent initial kidney fibrosis cascade through ameliorating initial kidney damage and improving kidney function. A superior 100% survival rate of treated animal group exhibits the potential of characterised PSCs to be used in a larger scale preclinical tumorigenicity and toxicity studies and subsequent clinical first-in-human studies.

Dynamic Changes in Erectile Function and Histological Architecture After Intracorporal Injection of Human Placental Stem Cells in a Pelvic Neurovascular Injury Rat Model

IntroductionThe human placenta provides a bountiful and noncontroversial source of stem cells which have the potential for regeneration of injured tissue. These cells may restore erectile function after neurovascular tissue injury such as that seen in radical pelvic surgeries and pelvic trauma. AimTo determine the effect of human placenta–derived stem cells on erectile function recovery and histological changes at various time points in a cavernous nerve injury rat model and to study the fate of injected stem cells throughout the regenerative process. MethodsHuman placental stem cells (PSCs) were dual labeled with monomeric Katushka far red fluorescent protein (mKATE)-renLUC using a lentivirus vector. A pelvic neurovascular injury–induced erectile dysfunction model was established in male, athymic rats by crushing the cavernous nerves and ligating the internal pudendal neurovascular bundles, bilaterally. At the time of defect creation, nonlabeled PSCs were injected into the corpus cavernosum at a concentration of 2.5 × 106 cells/0.2 mL. The phosphate-buffered saline–treated group served as the negative control group, and age-matched rats (age-matched controls) were used as the control group. Erectile function, histomorphological analyses, and Western blot were assessed at 1, 6, and 12 weeks after model creation. The distribution of implanted, dual-labeled PSCs was monitored using an in vivo imaging system (IVIS). Implanted cells were further tracked by detection of mKATE fluorescence in histological sections. Main Outcome MeasureThe main outcome measure includes intracavernous pressure/mean arterial pressure ratio, neural, endothelial, smooth muscle cell regeneration, mKATE fluorescence, and IVIS imaging. ResultsThe ratio of intracavernous pressure to mean arterial pressure significantly increased in PSC-injected rats compared with phosphate-buffered saline controls (P < 0.05) at the 6- and 12-week time points, reaching 72% and 68% of the age-matched control group, respectively. Immunofluorescence staining and Western blot analysis showed significant increases in markers of neurons (84.3%), endothelial cells (70.2%), and smooth muscle cells (70.3%) by 6 weeks in treatment groups compared with negative controls. These results were maintained through 12 weeks. IVIS analysis showed luminescence of implanted PSCs in the injected corpora immediately after injection and migration of cells to the sites of injury, including the incision site and periprostatic vasculature by day 1. mKATE fluorescence data revealed the presence of PSCs in the penile corpora and major pelvic ganglion at 1 and 3 days postoperatively. At 7 days, immunofluorescence of penile PSCs had disappeared and was diminished in the major pelvic ganglion. Clinical ImplicationsPlacenta-derived stem cells may represent a future “off-the-shelf” treatment to mitigate against development of erectile dysfunction after radical prostatectomy or other forms of pelvic injury. Strength & LimitationsSingle dose injection of PSCs after injury resulted in maximal functional recovery and tissue regeneration at 6 weeks, and the results were maintained through 12 weeks. Strategies to optimize adult stem cell therapy might achieve more effective outcomes for human clinical trials. ConclusionHuman PSC therapy effectively restores the erectile tissue and function in this animal model. Thus, PSC therapy may provide an attractive modality to lessen the incidence of erectile dysfunction after pelvic neurovascular injury. Further improvement in tissue regeneration and functional recovery may be possible using multiple injections or systemic introduction of stem cells.Gu X, Thakker PU, Matz EL, et al. Dynamic Changes in Erectile Function and Histological Architecture After Intracorporal Injection of Human Placental Stem Cells in a Pelvic Neurovascular Injury Rat Model. J Sex Med 2020;17:400–411.

Allogeneic Hematopoietic Stem Cell Transplantation (Allo-HSCT) with Human Placenta-Derived Stem Cells (HPDSC) Combined with Unrelated Cord Blood (UCB) for Malignant and Non-Malignant Disorders (IND 14949)

Background MAC or RTC followed by UCB donor allo-HSCT in children with malignant and non-malignant diseases is safe and effective (Geyer/Cairo, BJH 2011). However, concentration of CD34+ HPCs in UCB is low, leading to delayed hematopoietic reconstitution and high incidence of engraftment failure (Satwani/Cairo, BBMT 2013). HPDSCs are rich in HPCs, low in HLA Class I/II expression and T-cells, and have regenerative, anti-inflammatory, and immunosuppressive properties (Liao/Cairo, Stem Cells Trans Med 2018). Objective To determine the safety and efficacy of HPDSCs plus UCB for allo-HSCT in children. Design/Method UCB with TNC ≥ 5 × 107/kg (4/6 HLA match) or ≥ 3.5 × 107/kg (5-6/6 HLA match) were included. Patients received MAC or RTC followed by UCB plus HPDSC infusion. GVHD prophylaxis consisted of tacrolimus and MMF as previously described (Bhatia/Cairo, BBMT 2009). Results Twenty-eight patients ≤18 years were enrolled, 15 males. Mean age± SD was 6.8±5.5 years, (4 months-12 years). There were 12 patients with non-malignant diseases including ALD (2), CAT (1), CGD (1), SCID (2), DC (1), CN (1), SAA (2), LCH (1), and SDS (1) and 16 patients with malignant diseases including B-ALL- CR1 (4), B-ALL - CR2 (4), T-ALL – CR1 (1), AML-CR1 (4), JMML-CR1 (1), TLL - CR1 (1), and BL - CR2 (1). There were 13, 9, and 5 patients with 6/6, 5/6, and 4/6 HLA match, respectively. Mean UCB TNC±SD and CD34+ cell dose±SD infused were 0.77±0.5 × 108/kg and 0.48±0.59 × 106/kg, respectively. Mean HPDSC TNC±SD and CD34+ cell±SD dose were 0.96±3.51 × 108/kg and 0.05±0.05 × 106/kg, respectively. There were no SAEs associated with HPDSC infusions. Four patients were withdrawn for administration of alternative therapy after engraftment failure (3) or relapse (1). Probability of neutrophil engraftment by day 42 was 78.6%, median day 22 (13-53). Probability of platelet engraftment by day 100 in neutrophil engrafted patients was 86.4%, median day 42 (35-98) (Figure 1). Mean UCB chimerism was 92, 99, 96 and 99% at day 30, 60, 100 and 180, respectively. Average HPDSC chimerism was Conclusions These results suggest that UCB plus HPDSCs for Allo-HSCT is safe and well tolerated. Median day to platelet engraftment was lower than previously reported using UCB alone (Geyer/Cairo.BJH 2011). Probability of Grade 2-4 aGVHD was lower than previously reported using UCB alone, possibly due to the immunomodulatory effect of HPDSCs (Geyer/Cairo.BJH 2011). A larger cohort and longer follow-up is required to determine clinical significance.

Application of Tissue Engineering and Regenerative Medicine in Maternal-Fetal Medicine.

A rapid development of ultrasonography has enabled physicians to make earlier prenatal diagnosis of various fetal congenital diseases, in maternal-fetal medicine. Due to the significant mortality and irreversible damage to fetal vital organs during pregnancy, fetal surgeries have been tried in some congenital disease including congenital diaphragmatic hernia, twin-to-twin transfusion syndrome (TTTS), myelomeningocele (MMC), and lower urinary tract obstruction. However, open fetal surgery requires laparotomy followed by hysterotomy, which can cause preterm premature rupture of membrane (pPROM), oligohydramnios, preterm delivery, dehiscence of uterine wall, and other maternal complications during pregnancy. Minimally invasive approach using fetoscopy has been tried, and fetoscopic laser photocoagulation of vascular communications is currently considered as a treatment of choice for TTTS before 26weeks' gestation. However, more development of surgical instrument and innovative materials using tissue engineering are required to improve outcomes of fetoscopic surgery. Because iatrogenic pPROM is the major challenge after fetoscopic surgery, this review focuses on current development of materials for treatment of spontaneous or iatrogenic pPROM and recent experimental progress of tissue engineering-based technology in prenatal treatment of MMC. Placental tissue is an emerging material for regenerative medicine. This chapter will also review regenerative potential and experiments of placenta and placenta-derived stem cells, as well as prospects of "in utero stem cell therapy."

Alterations in IL-6/STAT3 Signaling by Korean Mistletoe Lectin Regulate the Self-Renewal Activity of Placenta-Derived Mesenchymal Stem Cells.

Korean mistletoe (Viscum album L. var. coloratum) lectin (VCA) is known as an anticancer drug. However, it is not clear whether VCA affects the self-renewal activity of mesenchymal stem cells (MSCs). Therefore, the objectives of this study were to analyze the effect of VCA on the proliferation of MSCs and expression of stemness markers. We also evaluated the usefulness of placenta-derived MSCs (PD-MSCs) as a screening tool. VCA was stably administered to MSCs, and analyzed self-renewal activities. The effect of IL-6 signaling on MSC proliferation was explored by quantitative methylation-specific PCR (qMSP) and western blot analysis. Compared with the control condition, low concentrations of VCA (10 pg/mL) induced an increase in the self-renewal activity of MSCs. Interestingly, a low concentration of VCA promoted IL-6 signaling in PD-MSCs through altered IL-6/STAT3 gene methylation. Furthermore, inhibition of IL-6 expression in PD-MSCs using an anti-IL-6 antibody caused a decrease in their self-renewal activity through IL-6/STAT3 signaling by altering IL-6/STAT3 gene methylation. These findings provide helpful data for understanding the mechanism of MSC self-renewal via VCA and show that VCA may be useful as a functional natural product for developing efficient therapies using placenta-derived stem cells.

Hematopoietic Stem Cell Transplantation with Human Placenta-Derived Stem Cells Combined with Unrelated Cord Blood for Malignant and Non-Malignant Disorders (IND 14949)

Background Myeloablative (MAC) or reduced toxicity conditioning (RTC) followed by UCBT in children with malignant and non-malignant diseases is safe and effective (Geyer/Cairo, BJH 2011). However, concentration of CD34+ HPCs in UCB is low, leading to delayed hematopoietic reconstitution and high incidence of engraftment failure (Satwani/Cairo, BBMT 2013). HPDSCs are rich in HPCs, low in HLA Class I/II expression and T-cells, and have regenerative, anti-inflammatory, and immunosuppressive properties (Liao/Cairo, Stem Cells Translational Medicine 2018). Objective To determine the safety and efficacy of HPDSC with UCBT in children with malignant and non-malignant diseases. Design/Method 4-6/6 HLA matched UCB with TNC ≥ 5 × 107/kg (4/6 HLA match) or ≥ 3.5 × 107/kg (5-6/6 HLA match) were included. Patients received MAC or RTC followed by UCB plus HPDSC infusion. GVHD prophylaxis consisted of tacrolimus and mycophenolate mofetil as previously described (Bhatia/Cairo, BBMT 2009). Results To date, 28 patients ≤18 years were enrolled, 15 males and 13 females. Mean age in years ± SD was 6.8±5.5. There were 12 patients with non-malignant disease including ALD (2), CAT (1), CGD (1), SCID (2), dyskeratosis congenita (1), congenital neutropenia (1), SAA (2), LCH (1), and SDS (1) and 16 patients with malignant disease including pre B-cell ALL- CR1 (4), pre B-cell ALL - CR2 (4), T-cell ALL – CR1 (1), AML-CR1 (4), JMML-CR1 (1), TLL - CR1 (1), and BL - CR2 (1). Mean UCB TNC±SD and CD34±SD infused were 7.7 × 107±5.0/kg and 0.48 × 106±0.59/kg, respectively. There were no SAEs associated with HPDSC infusions. Four patients were removed prior to day 180 due to progressive disease (1) and engraftment failure necessitating alternative treatment (3). Probability of neutrophil engraftment was 89.2%, median day 22 (13-53). Of neutrophil engrafted evaluable patients (n=22), the probability of platelet engraftment by day 100 was 90.9%, median day 42 (20-98). Of neutrophil engrafted, evaluable patients at day 30, 60, 100 and 180, mean whole blood UCB chimerism was 92, 99, 96 and 99%, respectively. Average whole blood HPDSC chimerism was Conclusions These results suggest that UCBT with HPDSC is safe and well tolerated, has a lower than expected probability of Grade 2-4 aGVHD, and results in robust immune reconstitution. A larger cohort and longer follow-up is required to determine the clinical significance of these findings.

Human neonatal stem cell‐derived skin substitute improves healing of severe burn wounds in a rat model

Conventional approaches can repair minor skin injuries; however, severe burn injuries require innovative approaches for efficient and better wound repair. Recent studies indicate that stem cell-based regenerative therapies can restore severe damaged skin both structurally and functionally. The current study aims to evaluate the wound healing potential of skin substitute derived from human neonatal stem cells (hNSCs) using a severe burn injury rat model. Amniotic epithelial cells (AECs) and mesenchymal stem cells (MSCs) were isolated from placenta (a source of neonatal stem cells) by explant culture method. After characterization, AECs and umbilical cord-MSCs were differentiated into keratinocyte and fibroblasts, respectively. Morphological changes, and expression of corresponding keratinocyte and fibroblast specific markers were used to verify differentiation into respective lineage. A skin substitute was developed by mixing hNSCs-derived skin cells (hNSCs-SCs) in plasma for transplantation in a rat model of severe burn injury. Results indicated that placenta-derived AECs and MSCs were efficiently differentiated into skin cells, that is, keratinocytes and fibroblasts, respectively, as indicated by morphological changes, immunostaining, and polymerase chain reaction analysis. Further, transplantation of hNSCs-SCs seeded in plasma significantly improved basic skin architecture, re-epithelization rate, and wound healing concurrent with reduced apoptosis. In conclusion, neonatal stem cell-derived skin substitute efficiently improved severe burn wounds in a rat model of burn injury. Unique properties of placenta-derived stem cells make them superlative candidates for the development of "off-the-shelf" artificial skin substitutes for future use.

Celularity pursues placental stem cells

Celularity has officially launched with $250 million in funding to develop treatments for cancer, autoimmune disease, diabetes, and even aging, all from placenta-derived stem cells. These stem cells, unlike blood stem cells, do not need to be matched to a patient’s immune system, making them an attractive option for use in many areas of medicine, including CAR-T immunotherapy and regenerative medicine.

Immunological compatibility status of placenta-derived stem cells is mediated by scaffold 3D structure

Placenta-derived amniotic epithelial cells (AECs), a great cell source for tissue engineering and stem cell therapy, are immunologically inert in their native state; however, immunological changes in these cells after culture and differentiation have challenged their applications. The aim of this study was to investigate the effect of 2D and 3D scaffolds on human lymphocyte antigens (HLA) expression by AECs. The effect of different preparation parameters including pre-freezing time and temperature was evaluated on 3D chitosan–gelatine scaffolds properties. Evaluation of MHC class I, HLA-DR and HLA-G expression in AECs after 7 d culture on 2D bed and 3D scaffold of chitosan–gelatine showed that culture of AECs on the 2D substrate up-regulated MHC class I and HLA-DR protein markers on AECs surface and down-regulated HLA-G protein. In contrast, 3D scaffold did not increase protein expression of MHC class I and HLA-DR. Moreover, HLA-G protein expression remained unchanged in 3D culture. These results confirm that 3D scaffold can remain AECs in their native immunological state and modification of physical properties of the scaffold is a key regulator of immunological markers at the gene and protein expression levels; a strategy which circumvents rejection challenge of amniotic stem cells to be translated into the clinic.