Comparison of explant-derived and enzymatic digestion-derived MSCs and the growth factors from Wharton's jelly

Induction of Human Wharton's Jelly of Umbilical Cord Derived Mesenchymal Stem Cells to Be Chondrocytes and Transplantation in Guinea Pig Model with Spontaneous Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease commonly found in elderly people and obese patients. Currently, OA treatments are determined based on their condition severity and a medical professional's advice. The aim of this study was to differentiate human Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs) into chondrocytes for transplantation in OA-suffering guinea pigs. hWJ-MSCs were isolated using the explant culture method, and then, their proliferation, phenotypes, and differentiation ability were evaluated. Subsequently, hWJ-MSCs-derived chondrocytes were induced and characterized based on immunofluorescent staining, qPCR, and immunoblotting techniques. Then, early-OA-suffering guinea pigs were injected with hyaluronic acid (HA) containing either MSCs or 14-day-old hWJ-MSCs-derived chondrocytes. Results showed that hWJ-MSCs-derived chondrocytes expressed specific markers of chondrocytes including Aggrecan, type II collagen, and type X collagen proteins and β-catenin, Sox9, Runx2, Col2a1, Col10a1, and ACAN gene expression markers. Administration of HA plus hWJ-MSCs-derived chondrocytes (HA-CHON) produced a better recovery rate of degenerative cartilages than HA plus MSCs or only HA. Histological assessments demonstrated no significant difference in Mankin's scores of recovered cartilages between HA-CHON-treated guinea pigs and normal articular cartilage guinea pigs. Transplantation of hWJ-MSCs-derived chondrocytes was more effective than undifferentiated hWJ-MSCs or hyaluronic acid for OA treatment in guinea pigs. This study provides a promising treatment to be used in early OA patients to promote recovery and prevent disease progression to severe osteoarthritis.

Cause and consequence of heterogeneity in human mesenchymal stem cells: Challenges in clinical application

Human mesenchymal stem cells (hMSCs) are mesoderm-derived adult stem cells with self-proliferation capacity, pluripotent differentiation potency, and excellent histocompatibility. These advantages make hMSCs a promising tool in clinical application. However, the majority of clinical trials using hMSC therapy for diverse human diseases do not achieve expectations, despite the prospective pre-clinical outcomes in animal models. This is partly attributable to the intrinsic heterogeneity of hMSCs. In this review, the cause of heterogeneity in hMSCs is systematically discussed at multiple levels, including isolation methods, cultural conditions, donor-to-donor variation, tissue sources, intra-tissue subpopulations, etc. Additionally, the effect of hMSCs heterogeneity on the contrary role in tumor progression and immunomodulation is also discussed. The attempts to understand the cellular heterogeneity of hMSCs and its consequences are important in supporting and improving therapeutic strategies for hMSCs.

Impact of multiple isolation procedures on the differentiation potential of adipose derived canine mesenchymal stem cells

OBJECTIVE

In regenerative biology, the most commonly used cells are adipose tissue-derived mesenchymal stem cells (AD-MSCs). This is due to the abundance and easy accessibility of AD-MSCs.

METHODS

In this study, canine AD-MSCs were harvested from different anatomical locations, i.e., subcutaneous (SC), omental (OM), and perirenal (PR). Various isolation techniques namely explants (TRT-I), collagenase-digestion (TRT-II), collagenase-digested explants (TRT-III), and trypsin-digested explants (TRT-IV) were used to segregate the MSCs to evaluate cell doubling time, viability, and adipogenic/osteogenic lineage differentiation potential.

RESULTS

The study showed that the SC stem cells had superior growth kinetics compared to other tissues, while the cells isolated through TRT-II performed better than the other cell isolation procedures. The metabolic status of cells isolated from dog adipose tissue indicated that all cells had adequate metabolic rates. However, SC-MSCs derived from TRT-III and TRT-IV outperformed those derived from TRT-I and TRT-II. The differentiation analysis revealed that cells differentiate into adipogenic and osteogenic lineage regardless of treatment, as demonstrated by positive oil red O (ORO) and Alizarin Red S (ALZ) stain. It is worth mentioning that cells derived from TRT-III had larger and more intracellular droplets compared to the other treatments. The TRT-I, -II, and -III showed greater osteogenic differentiation in cells isolated from PR and OM regions compared to SC-derived cells. However, the TRT-IV resulted in better osteogenic differentiation in cells from SC, followed by the OM and PR-derived cells.

CONCLUSION

It is concluded that all methods of MSCs isolation from adipose tissues are successful; however, the TRT-II had the highest rate of cell re-assortment from the SC, while, TRT-II and -IV are most suitable for isolating cells from PR and OM adipose tissue.

Development of Good Manufacturing Practice-Compatible Isolation and Culture Methods for Human Olfactory Mucosa-Derived Mesenchymal Stromal Cells

Demyelination in the central nervous system (CNS) resulting from injury or disease can cause loss of nerve function and paralysis. Cell therapies intended to promote remyelination of axons are a promising avenue of treatment, with mesenchymal stromal cells (MSCs) a prominent candidate. We have previously demonstrated that MSCs derived from human olfactory mucosa (hOM-MSCs) promote myelination to a greater extent than bone marrow-derived MSCs (hBM-MSCs). However, hOM-MSCs were developed using methods and materials that were not good manufacturing practice (GMP)-compliant. Before considering these cells for clinical use, it is necessary to develop a method for their isolation and expansion that is readily adaptable to a GMP-compliant environment. We demonstrate here that hOM-MSCs can be derived without enzymatic tissue digestion or cell sorting and without culture antibiotics. They grow readily in GMP-compliant media and express typical MSC surface markers. They robustly produce CXCL12 (a key secretory factor in promoting myelination) and are pro-myelinating in in vitro rodent CNS cultures. GMP-compliant hOM-MSCs are comparable in this respect to those grown in non-GMP conditions. However, when assessed in an in vivo model of demyelinating disease (experimental autoimmune encephalitis, EAE), they do not significantly improve disease scores compared with controls, indicating further pre-clinical evaluation is necessary before their advancement to clinical trials.

Enzyme-free isolation of mesenchymal stem cells from decidua basalis of the human placenta

Mesenchymal stem cells (MSCs), also referred to as "medicinal signaling cells," have gained prominence as candidates for cell-based therapy and in clinical trials owing to their regenerative and therapeutic properties. Here, we present a protocol for isolating MSCs from the decidua basalis layer of human placenta using an explant culture approach. We describe steps for collecting, disinfecting, and plating placental tissue. We then detail procedures for characterizing the isolated MSCs through flow cytometry and in vitro differentiation.

Comparison of SOX2 and POU5F1 Gene Expression in Leukapheresis-Derived CD34+ Cells before and during Cell Culture

Bone marrow is an abundant source of both hematopoietic as well as non-hematopoietic stem cells. Embryonic, fetal and stem cells located in tissues (adipose tissue, skin, myocardium and dental pulp) express core transcription factors, including the SOX2, POU5F1 and NANOG gene responsible for regeneration, proliferation and differentiation into daughter cells. The aim of the study was to examine the expression of SOX2 and POU5F1 genes in CD34-positive peripheral blood stem cells (CD34+ PBSCs) and to analyze the influence of cell culture on the expression of SOX2 and POU5F1 genes. The study material consisted of bone marrow-derived stem cells isolated by using leukapheresis from 40 hematooncology patients. Cells obtained in this process were subject to cytometric analysis to determine the content of CD34+ cells. CD34-positive cell separation was conducted using MACS separation. Cell cultures were set, and RNA was isolated. Real-time PCR was conducted in order to evaluate the expression of SOX2 and POU5F1 genes and the obtained data were subject to statistical analysis. We identified the expression of SOX2 and POU5F1 genes in the examined cells and demonstrated a statistically significant (p < 0.05) change in their expression in cell cultures. Short-term cell cultures (<6 days) were associated with an increase in the expression of SOX2 and POU5F1 genes. Thus, short-term cultivation of transplanted stem cells could be used to induce pluripotency, leading to better therapeutic effects.

Development of hydroxyapatite-coated nonwovens for efficient isolation of somatic stem cells from adipose tissues

Adipose-derived stem cells (ASCs) are an attractive cell source for cell therapy. Despite the increasing number of clinical applications, the methodology for ASC isolation is not optimized for every individual. In this study, we developed an effective material to stabilize explant cultures from small-fragment adipose tissues.

Methods

Polypropylene/polyethylene nonwoven sheets were coated with hydroxyapatite (HA) particles. Adipose fragments were then placed on these sheets, and their ability to trap tissue was monitored during explant culture. The yield and properties of the cells were compared to those of cells isolated by conventional collagenase digestion.

Results

Hydroxyapatite-coated nonwovens immediately trapped adipose fragments when placed on the sheets. The adhesion was stable even in culture media, leading to cell migration and proliferation from the tissue along with the nonwoven fibers. A higher fiber density further enhanced cell growth. Although cells on nonwoven explants could not be fully collected with cell dissociation enzymes, the cell yield was significantly higher than that of conventional monolayer culture without impacting stem cell properties.

Conclusions

Hydroxyapatite-coated nonwovens are useful for the effective primary explant culture of connective tissues without enzymatic cell dissociation.

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Hydroxyapatite-coated nonwovens enable explant culture of adipose tissue.

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ASCs migrated and proliferated from the tissue explants along the fibers in nonwovens.

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Nonwoven explants had significantly higher cell yield than conventional culture.

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Nonwoven culture did not impact stem cell properties of ASCs.

MSCs vs. iPSCs: Potential in therapeutic applications

Over the past 2 decades, mesenchymal stem cells (MSCs) have attracted a lot of interest as a unique therapeutic approach for a variety of diseases. MSCs are capable of self-renewal and multilineage differentiation capacity, immunomodulatory, and anti-inflammatory properties allowing it to play a role in regenerative medicine. Furthermore, MSCs are low in tumorigenicity and immune privileged, which permits the use of allogeneic MSCs for therapies that eliminate the need to collect MSCs directly from patients. Induced pluripotent stem cells (iPSCs) can be generated from adult cells through gene reprogramming with ectopic expression of specific pluripotency factors. Advancement in iPS technology avoids the destruction of embryos to make pluripotent cells, making it free of ethical concerns. iPSCs can self-renew and develop into a plethora of specialized cells making it a useful resource for regenerative medicine as they may be created from any human source. MSCs have also been used to treat individuals infected with the SARS-CoV-2 virus. MSCs have undergone more clinical trials than iPSCs due to high tumorigenicity, which can trigger oncogenic transformation. In this review, we discussed the overview of mesenchymal stem cells and induced pluripotent stem cells. We briefly present therapeutic approaches and COVID-19-related diseases using MSCs and iPSCs.

The Neural Multilineage Differentiation Capacity of Human Neural Precursors from the Umbilical Cord-Ready to Bench for Clinical Trials

Mesenchymal stem cells (MSC) are promising for regenerative medicine as they have a vast differentiation capacity, immunomodulatory properties and can be isolated from different tissues. Among them, the umbilical cord is considered a good source of MSC, as its collection poses no risk to donors and is unrelated to ethical issues. Furthermore, umbilical cord mesenchymal stem cells (UC-MSC) can differentiate into several cell lines, including neural lineages that, in the future, may become an alternative in the treatment of neurodegenerative diseases. This study used a natural functional biopolymer matrix (NFBX) as a membrane to differentiate UC-MSC into neurospheres and their Neural precursors without using neurogenic growth factors or gene transfection. Through the characterization of Neural precursors and differentiated cells, it was possible to demonstrate the broad potential for the differentiation of cells obtained through cultivation on this membrane. To demonstrate these Neural precursors' potential for future studies in neurodegenerative diseases, the Neural precursors from Wharton's jelly were differentiated into Schwann cells, oligodendrocytes, cholinergic-, dopaminergic- and GABAergic-like neurons.

Minimal Cube Explant Provides Optimal Isolation Condition of Mesenchymal Stem Cells from Umbilical Cord

BACKGROUND

Enzymatic digestion and explant method have been widely used for isolating umbilical cord-derived mesenchymal stem cells (UC MSCs), although there is still a strong need for robust protocols for optimal isolation for large-scale stem cell banks. This study aims to establish an explant method for clinical scale production of MSCs from human UC tissue and to characterize UC MSCs isolated and cultured with the explant method.

METHODS

UC MSCs were isolated by enzymatic digestion, minimal cube explant (MCE) 1-2, MCE 2-4, and MCE 10 and cultured, respectively. Also, human antibody array and basic fibroblast growth factor (bFGF) secretion in conditioned medium (CM) was analyzed. The cells were evaluated initial cell number, colony forming unit-fibroblast (CFU-F), proliferation capacity, CD marker expression, and multi-lineage differentiation. SA-β-gal assay as well as expression of p16, p21 and p53 was performed by RT-PCR.

RESULTS

MCE 2-4 is the most optimized method for isolation of small umbilical cord-derived fast proliferating cells (smumf cells) with the greatest number. MCE 2-4 had the highest secretion of various bioactive factors including bFGF. The MCE 2-4 provided significantly higher CD146 expression than enzymatic digestion, and that expression was maintained until P20. The gene expression of p16, p21, and p53 of smumf cells did not change until P10 and SA-β-gal activity did not increase until P14.

CONCLUSION

This study demonstrated that MCE 2-4 provided an optimal environment to isolate MSCs with quantity and quality from human whole UC tissue through secretion of various bioactive factors inherent to UC.

Efficacy of Mesenchymal Stem Cells from Human Exfoliated DeciduousTeeth and their Derivatives in Inflammatory Diseases Therapy

Mesenchymal stem cells derived from postnatal orofacial tissues can be readily isolated and possess diverse origins, for example, from surgically removed teeth or gingiva. These cells exhibit stem cell properties, strong potential for self-renewal, and show multi-lineage differentiation, and they have therefore been widely employed in stem cell therapy, tissue regeneration, and inflammatory diseases. Among them, stem cells from human exfoliated deciduous teeth [SHED] and their derivatives have manifested wide application in the treatment of diseases because of their outstanding advantages- including convenient access, easy storage, and less immune rejection. Numerous studies have shown that most diseases are closely associated with inflammation and that inflammatory diseases are extremely destructive, can lead to necrosis of organ parenchymal cells, and can deposit excessive extracellular ma- trix in the tissues. Inflammatory diseases are thus the principal causes of disability and death from many diseases worldwide. SHED and their derivatives not only exhibit the basic characteristics of stem cells but also exhibit some special properties of their own, particularly with regard to their great potential in inhib- iting inflammation and tissue regeneration. SHED therapy may provide a new direction for the treatment of inflammation and corresponding tissue defects. In this review, we critically analyze and summarize the latest findings on the behaviors and functions of SHED, serum‑free conditioned medium from SHED [SHED-CM], and extracellular vesicles, especially exosomes, from SHED [SHED-Exos], and discuss their roles and underlying mechanisms in the control of inflammatory diseases, thus further highlighting additional functions for SHED and their derivatives in future therapies.

Mesenchymal Stem/Stromal Cells Derived from Human and Animal Perinatal Tissues-Origins, Characteristics, Signaling Pathways, and Clinical Trials

Mesenchymal stem/stromal cells (MSCs) are currently one of the most extensively researched fields due to their promising opportunity for use in regenerative medicine. There are many sources of MSCs, of which cells of perinatal origin appear to be an invaluable pool. Compared to embryonic stem cells, they are devoid of ethical conflicts because they are derived from tissues surrounding the fetus and can be safely recovered from medical waste after delivery. Additionally, perinatal MSCs exhibit better self-renewal and differentiation properties than those derived from adult tissues. It is important to consider the anatomy of perinatal tissues and the general description of MSCs, including their isolation, differentiation, and characterization of different types of perinatal MSCs from both animals and humans (placenta, umbilical cord, amniotic fluid). Ultimately, signaling pathways are essential to consider regarding the clinical applications of MSCs. It is important to consider the origin of these cells, referring to the anatomical structure of the organs of origin, when describing the general and specific characteristics of the different types of MSCs as well as the pathways involved in differentiation.

Mesenchymal stromal cell therapy for coronavirus disease 2019: which? when? and how much?

Mesenchymal stromal cells (MSCs) are under active consideration as a treatment strategy for controlling the hyper-inflammation and slow disease progression associated with coronavirus disease 2019 (COVID-19). The possible mechanism of protection through their immunoregulatory and paracrine action has been reviewed extensively. However, the importance of process control in achieving consistent cell quality, maximum safety and efficacy—for which the three key questions are which, when and how much—remains unaddressed. Any commonality, if it exists, in ongoing clinical trials has yet to be analyzed and reviewed. In this review, the authors have therefore compiled study design data from ongoing clinical trials to address the key questions of “which” with regard to tissue source, donor profile, isolation technique, culture conditions, long-term culture and cryopreservation of MSCs; “when” with regard to defining the transplantation window by identifying and staging patients based on their pro-inflammatory profile; and “how much” with regard to the number of cells in a single administration, number of doses and route of transplantation. To homogenize MSC therapy for COVID-19 on a global scale and to make it readily available in large numbers, a shared understanding and uniform agreement with respect to these fundamental issues are essential.

Biological Aspects and Clinical Applications of Mesenchymal Stem Cells: Key Features You Need to be Aware of

Mesenchymal Stem Cells (MSCs), a form of adult stem cells, are known to have a selfrenewing property and the potential to specialize into a multitude of cells and tissues such as adipocytes, cartilage cells, and fibroblasts. MSCs can migrate and home to the desired target zone where inflammation is present. The unique characteristics of MSCs in repairing, differentiation, regeneration, and the high capacity of immune modulation have attracted tremendous attention for exerting them in clinical purposes, as they contribute to the tissue regeneration process and anti-tumor activity. The MSCs-based treatment has demonstrated remarkable applicability towards various diseases such as heart and bone malignancies, and cancer cells. Importantly, genetically engineered MSCs, as a stateof- the-art therapeutic approach, could address some clinical hurdles by systemic secretion of cytokines and other agents with a short half-life and high toxicity. Therefore, understanding the biological aspects and the characteristics of MSCs is an imperative issue of concern. Herein, we provide an overview of the therapeutic application and the biological features of MSCs against different inflammatory diseases and cancer cells. We further shed light on MSCs' physiological interaction, such as migration, homing, and tissue repairing mechanisms in different healthy and inflamed tissues.

The preclinical and clinical implications of fetal adnexa derived mesenchymal stromal cells in wound healing therapy

Mesenchymal stromal cells (MSCs) isolated from fetal adnexa namely amniotic membrane/epithelium, amniotic fluid and umbilical cord have hogged the limelight in recent times, as a proposed alternative to MSCs from conventional sources. These cells which are identified as being in a developmentally primitive state have many advantages, the most important being the non-invasive nature of their isolation procedures, absence of ethical concerns, proliferation potential, differentiation abilities and low immunogenicity. In the present review, we are focusing on the potential preclinical and clinical applications of different cell types of fetal adnexa, in wound healing therapy. We also discuss the isolation-culture methods, cell surface marker expression, multi-lineage differentiation abilities, immune-modulatory capabilities and their homing property. Different mechanisms involved in the wound healing process and the role of stromal cells in therapeutic wound healing are highlighted. Further, we summarize the findings of the cell delivery systems in skin lesion models and paracrine functions of their secretome in the wound healing process. Overall, this holistic review outlines the research findings of fetal adnexa derived MSCs, their usefulness in wound healing therapy in human as well as in veterinary medicine.

Application of Mesenchymal Stem Cells in Inflammatory and Fibrotic Diseases

Mesenchymal stem cells (MSCs) are multipotent stem cells that can be isolated from various tissues in the adult body. MSCs should be characterized by three criteria for regenerative medicine. MSCs must (1) adhere to plastic surfaces, (2) express specific surface antigens, and (3) differentiate into mesodermal lineages, including chondrocytes, osteoblasts, and adipocytes, in vitro. Interestingly, MSCs have immunomodulatory features and secrete trophic factors and immune receptors that regulate the microenvironment in host tissue. These specific and unique therapeutic properties make MSCs ideal as therapeutic agents in vivo. Specifically, pre-clinical and clinical investigators generated inflammatory and fibrotic diseases models, and then transplantation of MSCs into diseases models for therapeutic effects investigation. In this review, we characterize MSCs from various tissues and describe their applications for treating various inflammation and fibrotic diseases.

Mesenchymal Stem/Progenitor Cells: The Prospect of Human Clinical Translation

Mesenchymal stem/progenitor cells (MSCs) are key players in regenerative medicine, relying principally on their differentiation/regeneration potential, immunomodulatory properties, paracrine effects, and potent homing ability with minimal if any ethical concerns. Even though multiple preclinical and clinical studies have demonstrated remarkable properties for MSCs, the clinical applicability of MSC-based therapies is still questionable. Several challenges exist that critically hinder a successful clinical translation of MSC-based therapies, including but not limited to heterogeneity of their populations, variability in their quality and quantity, donor-related factors, discrepancies in protocols for isolation, in vitro expansion and premodification, and variability in methods of cell delivery, dosing, and cell homing. Alterations of MSC viability, proliferation, properties, and/or function are also affected by various drugs and chemicals. Moreover, significant safety concerns exist due to possible teratogenic/neoplastic potential and transmission of infectious diseases. Through the current review, we aim to highlight the major challenges facing MSCs' human clinical translation and shed light on the undergoing strategies to overcome them.

Comparison of umbilical cord tissue-derived mesenchymal stromal cells isolated from cryopreserved material and extracted by explantation and digestion methods utilizing a split manufacturing model

BACKGROUND AIMS

Umbilical cord (UC) tissue is recognized as an advantageous source of mesenchymal stromal cells (MSCs), whose therapeutic properties are being actively evaluated in pre-clinical and clinical trials. In recognition of its potential value, storage of UC tissue or cells from UC tissue in newborn stem cell banks is now commonplace; however, strategies for isolating UC-derived MSCs (UCMSCs) from UC tissue have not been standardized. The majority of newborn stem cell banks take one of two approaches to cord tissue processing and cryopreservation: enzymatic digestion of the fresh tissue with cryopreservation of the subsequent cell suspension or cryopreservation of the tissue as a composite whole with later, post-thaw isolation of cells by explantation. Evaluation of UCMSCs derived by these two principal preparation and cryopreservation strategies is important to understanding whether the methods currently employed by newborn stem cell banks retain the desirable clinical attributes of UC cells.

METHODS

UCMSCs were isolated from 10 UC tissue samples by both explantation and enzymatic digestion methods to allow for comparison of cells from the same donor. Cell isolates from both methods were compared pre- and post-cryopreservation as well as after serial passaging. Cell viability, morphology, growth kinetics, immunophenotype, cytokine secretion and differentiation capacity were evaluated.

RESULTS

UCMSCs could be derived from fresh UC tissue by both explantation and digestion methods and from thawed UC tissue by explantation. Initial cell populations isolated by digestion were heterogeneous and took longer to enrich for UCMSCs in culture than populations obtained by explantation. However, once isolated and enriched, UCMSCs obtained by either method showed no significant difference in viability, morphology, rate of proliferation, surface marker expression, levels of cytokine secretion or differentiation capacity.

CONCLUSIONS

Derivation of UCMSCs by explantation after thawing UC cryopreserved as a composite tissue may be favorable in terms of initial purity and number of cells achievable by a specific passage. However, we observed no evidence of functional difference between UCMSCs derived by explanation or digestion, suggesting that cells isolated from cryopreserved material obtained by either method maintain their therapeutic properties.

A compound of concentrated growth factor and periodontal ligament stem cell-derived conditioned medium

The aim of this study was to determine the in vitro effect of a compound of concentrated growth factor (CGF) and periodontal ligament stem cell-derived conditioned medium (PDLSCs-CM) as a potential product for future applications in periodontal tissue regeneration. Isolated PDLSCs were characterized using flow cytometry and differentiation into osteoblasts and adipocytes cells. PDLSCs-CM and CGF were prepared and lyophilized. To determine the optimal concentration of the CGF-CM compound, the proliferation of PDLSCs after exposure to a wide range of different concentrations of CGF, CM, or their combination (CGF + CM) was investigated by methyl thiazol tetrazolium assay. Successful isolation of PDLSCs was confirmed by high expression of mesenchymal surface markers and differentiation into osteoblasts and adipocytes. PDLSCs showed higher proliferation in the 6.25 mg/mL concentration of CM and 94 μg/mL concentration of CGF. High concentrations of CGF and CM markedly inhibited the proliferation of PDLCs (p < 0.05). The exposure of PDLSCs to the compound of 10% CM + 90% CGF significantly increased the cell proliferation (p < 0.05). The results showed that CGF, CM, or their combination exert a proliferative effect on cells at a certain concentration. Further investigation on the synergistic effect of this compound may approve its application for periodontal regeneration.

PF-127 hydrogel plus sodium ascorbyl phosphate improves Wharton's jelly mesenchymal stem cell-mediated skin wound healing in mice

Background

Factors such as poor engraftment, retention, and survival of the transplanted stem cells are deemed to limit their therapeutic efficacy for wound regeneration. Hence, it is necessary to explore these issues in order to resolve them. In this study, we aim to investigate the role of Pluronic F-127 (PF-127) hydrogel plus antioxidant sodium ascorbyl phosphate (SAP) in enhancing Wharton’s jelly mesenchymal stem cell (WJMSC)-mediated effectiveness on full-thickness skin wound healing in mice.

Methods

First, the cytotoxicity of PF-127 and the biological effect of SAP on the survival of WJMSCs were tested in vitro using cell viability and proliferation assays. Next, a cell suspension containing WJMSCs, PF-127, and SAP was topically administered onto an 8-mm diameter excisional full-thickness wound bed. Eight days after transplantation, the mice were sacrificed and the skin tissue was excised for histological and immunohistochemical analysis. Finally, in vivo distribution of transplanted WJMSCs was traced to investigate cell engraftment and the potential therapeutic mechanism.

Results

PF-127 was found to be cytotoxic to WJMSCs while SAP significantly improved the survival of PF-127-embedded WJMSCs. When this combination was topically transplanted onto the wound bed, wound healing was facilitated and dermis regeneration was achieved on the 8th day after surgery, as evidenced by an increase in dermal thickness, newly developed hair follicles, and collagen fiber deposition accompanied by a reduction in scar width. Further, immunohistochemical analysis demonstrated a higher number of anti-inflammatory M2 macrophages, proliferating cells, and newly formed blood vessels in the WJMSCs/PF-127/SAP group relative to all other groups. In addition, in vivo tracking results revealed a highly enhanced engraftment of WJMSCs accumulated in the dermis in the WJMSCs/PF-127/SAP group.

Conclusions

SAP significantly improves the survival of WJMSCs in PF-127 encapsulation. Further, PF-127 plus SAP is an effective combination that enhances WJMSC engraftment in the dermis, which then promotes full-thickness wound healing through potential M2 macrophage formation and angiogenesis.

Expanded Differentiation Capability of Human Wharton's Jelly Stem Cells Toward Pluripotency: A Systematic Review

Human Wharton's jelly stem cells (HWJSC) can be efficiently isolated from the umbilical cord, and numerous reports have demonstrated that these cells can differentiate into several cell lineages. This fact, coupled with the high proliferation potential of HWJSC, makes them a promising source of stem cells for use in tissue engineering and regenerative medicine. However, their real potentiality has not been established to date. In the present study, we carried out a systematic review to determine the multilineage differentiation potential of HWJSC. After a systematic literature search, we selected 32 publications focused on the differentiation potential of these cells. Analysis of these studies showed that HWJSC display expanded differentiation potential toward some cell types corresponding to all three embryonic cell layers (ectodermal, mesodermal, and endodermal), which is consistent with their constitutive expression of key pluripotency markers such as OCT4, SOX2, and NANOG, and the embryonic marker SSEA4. We conclude that HWJSC can be considered cells in an intermediate state between multipotentiality and pluripotentiality, since their proliferation capability is not unlimited and differentiation to all cell types has not been demonstrated thus far. These findings support the clinical use of HWJSC for the treatment of diseases affecting not only mesoderm-type tissues but also other cell lineages. Impact statement Human Wharton's jelly stem cells (HWJSC) are mesenchymal stem cells that are easy to isolate and handle, and that readily proliferate. Their wide range of differentiation capabilities supports the view that these cells can be considered pluripotent. Accordingly, HWJSC are one of the most promising cell sources for clinical applications in advanced therapies.

Reproducible Derivation and Expansion of Corneal Mesenchymal Stromal Cells for Therapeutic Applications

Purpose

A reproducible protocol for the production of corneal mesenchymal stem/stromal cells (cMSCs) is necessary for potential clinical applications. We aimed to describe successful generation and expansion of cMSCs using an explant method.

Methods

Corneoscleral rims of human cadaveric eyes were divided into four pieces and used as explants to allow outgrowth of cMSCs (passage 0, or P0). The cells were subcultured at a 1:10 ratio until passage 5 (P5). The characteristics as well as therapeutic effects of expanded cMSCs were evaluated both in vitro, using a scratch assay, and in vivo using epithelial debridement and chemical injury mouse models.

Results

All explants demonstrated outgrowth of cells by 7 days. Although the initial outgrowth included mixed mesenchymal and epithelial cells, by P1 only cMSCs remained. By subculturing each flask at a ratio of 1:10, the potential yield from each cornea was approximately 12 to 16 × 10¹⁰ P5 cells. P5 cMSCs demonstrated the cell surface markers of MSCs. The secretome of P5 cMSCs induced faster closure of wounds in an in vitro scratch assay. Subconjunctival injection of P5 cMSCs in mouse models of mechanical corneal epithelial debridement or ethanol injury led to significantly faster wound healing and decreased inflammation, relative to control.

Conclusions

cMSCs can be reproducibly derived from human cadaveric corneas using an explant method and expanded with preservation of characteristics and corneal wound healing effects.

Translational Relevance

The results of our study showed that cMSCs produced using this scheme can be potentially used for clinical applications.

Large-Scale Automated Hollow-Fiber Bioreactor Expansion of Umbilical Cord-Derived Human Mesenchymal Stromal Cells for Neurological Disorders

Neurodegenerative disorders present a broad group of neurological diseases and remain one of the greatest challenges and burdens to mankind. Maladies like amyotrophic lateral sclerosis, Alzheimer's disease, stroke or spinal cord injury commonly features astroglia involvement (astrogliosis) with signs of inflammation. Regenerative, paracrine and immunomodulatory properties of human mesenchymal stromal cells (hMSCs) could target the above components, thus opening new therapeutic possibilities for regenerative medicine. A special interest should be given to hMSCs derived from the umbilical cord (UC) tissue, due to their origin, properties and lack of ethical paradigms. The aim of this study was to establish standard operating and scale-up good manufacturing practice (GMP) protocols of UC-hMSCs isolation, characterization, expansion and comparison of cells' properties when harvested on T-flasks versus using a large-scale bioreactor system. Human UC-hMSCs, isolated by tissue explant culture technique from Wharton's jelly, were harvested after reaching 75% confluence and cultured using tissue culture flasks. Obtained UC-hMSCs prior/after the cryopreservation and after harvesting in a bioreactor, were fully characterized for "mesenchymness" immunomodulatory, tumorigenicity and genetic stability, senescence and cell-doubling properties, as well as gene expression features. Our study demonstrates an efficient and simple technique for large scale UC-hMSCs expansion. Harvesting of UC-hMSCs' using classic and large scale methods did not alter UC-hMSCs' senescence, genetic stability or in vitro tumorigenicity features. We observed comparable growth and immunomodulatory capacities of fresh, frozen and expanded UC-hMSCs. We found no difference in the ability to differentiate toward adipogenic, osteogenic and chondrogenic lineages between classic and large scale UC-hMSCs expansion methods. Both, methods enabled derivation of genetically stabile cells with typical mesenchymal features. Interestingly, we found significantly increased mRNA expression levels of neural growth factor (NGF) and downregulated insulin growth factor (IGF) in UC-hMSCs cultured in bioreactor, while IL4, IL6, IL8, TGFb and VEGF expression levels remained at the similar levels. A culturing of UC-hMSCs using a large-scale automated closed bioreactor expansion system under the GMP conditions does not alter basic "mesenchymal" features and quality of the cells. Our study has been designed to pave a road toward translation of basic research data known about human UC-MSCs for the future clinical testing in patients with neurological and immunocompromised disorders. An industrial manufacturing of UC-hMSCs next will undergo regulatory approval following advanced therapy medicinal products (ATMP) criteria prior to clinical application and approval to be used in patients.

An efficient protocol to generate placental chorionic plate-derived mesenchymal stem cells with superior proliferative and immunomodulatory properties

Background

Placenta-derived MSCs (P-MSCs) represent a promising tool for cell-based therapeutic applications. However, the increasing demand for P-MSCs in clinical trials makes high quality and large number of P-MSCs mandatory. Here, we aim to develop an efficient protocol for P-MSC isolation and culture.

Methods

The modified explant culture (MEC) method by combining an initial mild enzymatic reaction with the subsequent explant culture was developed to simultaneously produce various P-MSCs from the different regions of the placenta in serum-free medium (SFM). Its isolation efficiencies, cell yield, and proliferative capacity were compared with the conventional explant culture (EC) method. Furthermore, we determined whether functional properties of P-MSCs are affected by the used tissue-harvesting sites in terms of their proliferation, migration, and the immunomodulatory effect on macrophage.

Results

The MEC method achieved higher yield and shorter time in primary cell confluence in SFM compared with the conventional method. The harvested cells possessed the MSC characteristics and demonstrated significantly stronger proliferation ability. Importantly, MSCs derived from chorionic plate (CP-MSCs) were found to exhibit superior properties to the other P-MSCs in proliferation and migration capacity, maintaining the fetal origin over serial passages. Notably, CP-MSCs show stronger ability in regulating macrophage polarization from M1 to M2.

Conclusion

Our study developed an efficient and high-yield technique to produce high-quality P-MSCs from the placenta, hence serving as an optimal source of MSCs for clinical application.

Characteristics and clinical applications of Wharton's jelly-derived mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) are widely used in the clinic because they involve fewer ethical issues and safety concerns compared to other stem cells such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). MSCs derived from umbilical cord Wharton's jelly (WJ-MSCs) have excellent proliferative potential and a faster growth rate and can retain their multipotency for more passages in vitro compared to adult MSCs from bone marrow or adipose tissue. WJ-MSCs are used clinically for repairing tissue injuries of the spinal cord, liver and heart with the aim of regenerating tissue. On the other hand, WJ-MSCs are also used clinically to ameliorate immune-mediated diseases based on their ability to modulate immune responses. In the field of tissue engineering, WJ-MSCs capable of differentiating into multiple cell lineages have been used to produce a variety of engineered tissues in vitro that can then be transplanted in vivo. This review discusses the characteristics of WJ-MSCs, the differences between WJ-MSCs and adult MSCs, clinical studies involving WJ-MSCs and future perspectives of WJ-MSC research and clinical applications. To summarize, WJ-MSCs have shown promise in treating a variety of diseases clinically. However, most clinical trials/studies reported thus far are relatively smaller in scale. The collected evidence is insufficient to support the routine use of WJ-MSC therapy in the clinic. Thus, rigorous clinical trials are needed in the future to obtain more information on WJ-MSC therapy safety and efficacy.

Isolation of umbilical cord mesenchymal stem cells using human blood derivatives accompanied with explant method

Background

Mesenchymal stem cells (MSCs) are multipotent cells which can be isolated from many sources including umbilical cord. Isolation protocols are depended on either explant or enzymatic methods. Although fetal bovine serum (FBS) is used as a supplement in isolation and expansion of MSCs, human blood derivatives such as cord blood serum (CBS) and platelet lysate (PL) are attractive substitutes of FBS which overcome impediments of using FBS in clinical setups.

Methods

Here we compared the effect of using CBS, PL and FBS supplemented media in isolation of umbilical cord tissue derived MSCs by using explant method. To do that we cultured umbilical cord tissue explant in either CBS or PL or FBS supplemented media. Isolated cells were quantified, their morphology was assessed and Cells in passage 3 were characterized based on their immunophenotyping and their potential for differentiation into adipocytes and osteocytes. Moreover, proliferation of cells was assessed by crystal violet staining.

Results

All the three media succeeded to isolate MSCs and maintain their stemness characteristics. However, the highest number of isolated cells were obtained using CBS, ~10-fold more than FBS, while the number of isolated cells obtained using PL was ~2-fold more than FBS. Moreover, crystal violet showed that both PL and CBS promote proliferation of MSCs more than FBS.

Conclusions

Our data suggest that, although all supplements maintain stemness characteristics of MSCs when used to isolate those cells by explant method, using human blood derived supplements is more effective than FBS. In the same context CBS is more effective than PL.

Banking Mesenchymal Stromal Cells from Umbilical Cord Tissue: Large Sample Size Analysis Reveals Consistency Between Donors

Mesenchymal stromal cells (MSCs) have emerged as candidate cells with therapeutic potential to treat different pathologies. The underlying mechanism is paracrine signaling. The cells secrete proteins that can impact inflammation, apoptosis, angiogenesis, and cell proliferation. All are important in wound healing and tissue regeneration. Although the bone marrow has been the most widely used source of MSCs, umbilical cord tissue (CT) presents a source that is just starting to be used in the clinic, yet can be obtained with more ease and easily stored. Here, we characterize CT‐MSCs obtained from multiple donors by analyzing cell surface proteins, differentiation capacity, and proteome profile. Analysis of low, medium, and high passage cells indicates that the morphology and proliferation rate stay constant and with the exception of cluster of differentiation (CD) 105 at late passage, there are no changes in the cell surface protein characteristics, indicating the population does not change with passage. TNF‐stimulated gene 6 protein was measured in a subset of samples and variable expression was observed, but this did not impact the ability of the cells to enhance skin regeneration. In conclusion, CT‐MSC represents a consistent, easily accessible source of cells for cell therapy. stem cells translational medicine2019;8:1041–1054

First decade of clinical trials and published studies with mesenchymal stromal cells from umbilical cord tissue

Aim: This is the first analysis of both clinical trials and published studies that employ umbilical cord mesenchymal stromal cells, for the decade 2007–2017. Materials & methods: Searching international databases, we found 178 registered trials and 98 publications. Results: Among the registered clinical trials, 20% have resulted in publications so far. Among the publications, 18% report safety and 74% report some form of improvement. Between 36 and 45% of the publications do not report aspects of the cell manufacturing, including isolation method, culture medium or number of culture passages. Conclusion: Analyses that link trials with publications can elucidate factors that promote study completion and publication. More full disclosure of cell manufacturing is needed to evaluate the efficacy of mesenchymal stromal cell isolated from umbilical cord tissue (UC-MSC) products.

Stem cells in the treatment of diabetes mellitus - Focus on mesenchymal stem cells

Diabetes mellitus type 1 and type 2 have become a global epidemic with dramatically increasing incidences. Poorly controlled diabetes is associated with severe life-threatening complications. Beside traditional treatment with insulin and oral anti-diabetic drugs, clinicians try to improve patient's care by cell therapies using embryonic stem cells (ESC), induced pluripotent stem cells (iPSC) and adult mesenchymal stem cells (MSC). ESC display a virtually unlimited plasticity, including the differentiation into insulin producing β-cells, but they raise ethical concerns and bear, like iPSC, the risk of tumours. IPSC may further inherit somatic mutations and remaining somatic transcriptional memory upon incomplete re-programming, but allow the generation of patient/disease-specific cell lines. MSC avoid such issues but have not been successfully differentiated into β-cells. Instead, MSC and their pericyte phenotypes outside the bone marrow have been recognized to secrete numerous immunomodulatory and tissue regenerative factors. On this account, the term 'medicinal signaling cells' has been proposed to define the new conception of a 'drug store' for injured tissues and to stay with the MSC nomenclature. This review presents the biological background and the resulting clinical potential and limitations of ESC, iPSC and MSC, and summarizes the current status quo of cell therapeutic concepts and trials.

Mesenchymal stem cells in preclinical cancer cytotherapy: a systematic review

Mesenchymal stem cells (MSC) comprise a heterogeneous population of rapidly proliferating cells that can be isolated from adult (e.g., bone marrow, adipose tissue) as well as fetal (e.g., umbilical cord) tissues (termed bone marrow (BM)-, adipose tissue (AT)-, and umbilical cord (UC)-MSC, respectively) and are capable of differentiation into a wide range of non-hematopoietic cell types. An additional, unique attribute of MSC is their ability to home to tumor sites and to interact with the local supportive microenvironment which rapidly conceptualized into MSC-based experimental cancer cytotherapy at the turn of the century. Towards this purpose, both naïve (unmodified) and genetically modified MSC (GM-MSC; used as delivery vehicles for the controlled expression and release of antitumorigenic molecules) have been employed using well-established in vitro and in vivo cancer models, albeit with variable success. The first approach is hampered by contradictory findings regarding the effects of naïve MSC of different origins on tumor growth and metastasis, largely attributed to inherent biological heterogeneity of MSC as well as experimental discrepancies. In the second case, although the anti-cancer effect of GM-MSC is markedly improved over that of naïve cells, it is yet apparent that some protocols are more efficient against some types of cancer than others. Regardless, in order to maximize therapeutic consistency and efficacy, a deeper understanding of the complex interaction between MSC and the tumor microenvironment is required, as well as examination of the role of key experimental parameters in shaping the final cytotherapy outcome. This systematic review represents, to the best of our knowledge, the first thorough evaluation of the impact of experimental anti-cancer therapies based on MSC of human origin (with special focus on human BM-/AT-/UC-MSC). Importantly, we dissect the commonalities and differences as well as address the shortcomings of work accumulated over the last two decades and discuss how this information can serve as a guide map for optimal experimental design implementation ultimately aiding the effective transition into clinical trials.

Differentiation Potential of Human Wharton's Jelly-Derived Mesenchymal Stem Cells and Paracrine Signaling Interaction Contribute to Improve the In Vitro Maturation of Mouse Cumulus Oocyte Complexes

In vitro maturation (IVM) in cumulus oocyte complexes (COCs) can be improved by the presence of human Wharton's jelly-derived MSCs (hWJ-MSCs), under specific culture conditions. COCs were cultured in twelve different culture systems, composed of four stock media, stock media conditioned with hWJ-MSCs, and stock media in which the oocytes were indirectly cocultured with the hWJ-MSCs. The rates of maturation to meiosis II were compared among the groups. G2-PLUS and coculture with DMEM-F12 were the most efficient systems for the maturation of COCs. The fertilization rate and rate of development to the blastocyst stage were compared between these two groups. Moreover, hWJ-MSC-conditioned media showed no benefits for the COC-IVM. The analysis of OCT4 expression of hWJ-MSCs in G1-PLUS, TYH, and G2-PLUS showed a downregulation of OCT4 by 25.9, 24.7, and 6.6%, respectively, compared to that in hWJ-MSCs cultured in DMEM-F12. Finally, we have demonstrated that two prerequisites appeared to be necessary for the hWJ-MSCs to improve the IVM of COCs: hWJ-MSCs' differentiation potential and the presence of coordinated paracrine interaction between the stem cells and COCs. Under the appropriate conditions, the paracrine factors produced in the coculture system with DMEM-F12 may help to develop synthetic media for successful in vitro culture of COCs.

Potential Therapeutic Strategy in Chronic Obstructive Pulmonary Disease Using Pioglitazone-Augmented Wharton's Jelly-Derived Mesenchymal Stem Cells

Background

A recent study reported that mesenchymal stem cells possess potential cellular therapeutic properties for treating patients with chronic obstructive pulmonary disease, which is characterized by emphysema. We examined the potential therapeutic effect of Wharton's Jelly-derived mesenchymal stem cells (WJMSCs), following pretreatment with pioglitazone, in lung regeneration mouse emphysema models.

Methods

We used two mouse emphysema models, an elastase-induced model and a cigarette smoke-induced model. We intravenously injected WJMSCs (1×10⁴/mouse) to mice, pretreated or not, with pioglitazone for 7 days. We measured the emphysema severity by mean linear intercepts (MLI) analysis using lung histology.

Results

Pioglitazone pretreated WJMSCs (pioWJMSCs) were associated with greater lung regeneration than non-augmented WJMSCs in the two mouse emphysema models. In the elastase-induced emphysema model, the MLIs were 59.02±2.42 µm (n=6), 72.80±2.87 µm (n=6), for pioWJMSCs injected mice, and non-augmented WJMSCs injected mice, respectively (p<0.01). Both pioWJMSCs and non-augmented WJMSCs showed regenerative effects in the cigarette smoke emphysema model (MLIs were 41.25±0.98 [n=6] for WJMSCs and38.97±0.61 µm [n=6] for pioWJMSCs) compared to smoking control mice (51.65±1.36 µm, n=6). The mean improvement of MLI appeared numerically better in pioWJMSCs than in non-augmented WJMSCs injected mice, but the difference did not reach the level of statistical significance (p=0.071).

Conclusion

PioWJMSCs may produce greater lung regeneration, compared to non-augmented WJMSCs, in a mouse emphysema model.

Development of a novel explant culture method for the isolation of mesenchymal stem cells from human breast tumor

BACKGROUND

Mesenchymal stem cells (MSCs) were isolated from various sources, including various types of tumors. However choosing an appropriate isolation method is an important step in obtaining cells with optimal quality and yield in companion with economical considerations. The purpose of this study was to isolate more pure MSCs from human breast tumor tissue by a modified explant culture method.

METHODS AND MATERIALS

The tumor tissues (n = 8) were cut into 1 to 3-mm cube-like pieces (explant). Each explant was placed in a well of 24-well format plates, cultured in Dulbecco's Modified Eagle's medium (DMEM), and maintained at 37°C with 5% humidified incubator. Morphological phenotypes of the cells were surveyed by an inverted microscope and wells with rather homogenous fibroblast-like morphology cell were considered as positive and selected for more expansion and characterization.

RESULTS

A total of 185 wells, 63.7% of wells were positive that were chosen for expansion. Flowcytometry analysis demonstrated that isolated cells were positive for CD73, CD44, CD29, CD105, and CD90 but negative for CD11b, CD45, CD34, and HLA‑DR. In addition, cells possessed the capability of multipotential differentiation into osteoblasts and adipocytes.

Collagenase Impacts the Quantity and Quality of Native Mesenchymal Stem/Stromal Cells Derived during Processing of Umbilical Cord Tissue

Enzymes are commonly used as a biochemical means to liberate cells from a host of tissues for use in in vitro studies and/or in vivo transplantations. However, very little understanding exists of the biological and functional effects that enzymes have on cells during the process of releasing the native cells from a given tissue. One specific reason for this is that no technology has existed as a nonenzymatic control to compare baseline biology and function for a given processed tissue. We have developed a sterile, onetime use, disposable system (referred to as the AuxoCell Processing System or AC:Px®) that allows for processing of solid tissue in a closed, standardized system using mechanical means to liberate cells without the need and/or use of any biochemical, enzymatic digestion. In this report, for the first time, we directly compare the cellular outputs derived from processing the same umbilical cord tissue (UCT) in the presence and absence of collagenase. In the presence of collagenase, we observed on average, approximately a 2.7-fold reduction in native mesenchymal stem/stromal cell (MSC) yields and a reduction in MSC-specific markers CD90, CD29, CD105, CD73, CD44, CD36, CD49b, CD49a, CD146, CD295, and CD166 and in endothelial marker CD31. These data directly exhibit that the use of collagenase to process UCT to release cells impacts cell recovery with respect to number and cell surface marker expression and, hence, could affect the in vivo function of the recovered native cellular population.

Evaluation of Peripheral Blood and Cord Blood Platelet Lysates in Isolation and Expansion of Multipotent Mesenchymal Stromal Cells

Abstract: Background: Multipotent Mesenchymal Stromal Cells (MSCs) are used in tissue engineering and regenerative medicine. The in vitro isolation and expansion of MSCs involve the use of foetal bovine serum (FBS). However, many concerns have been raised regarding the safety of this product. In this study, alternative additives derived either from peripheral or cord blood were tested as an FBS replacement. Methods: Platelet lysates (PL) from peripheral and cord blood were used for the expansion of MSCs. The levels of growth factors in peripheral blood (PB) and cord blood (CB) PLs were determined using the Multiple Reaction Monitoring (MRM). Finally, the cell doubling time (CDT), tri-lineage differentiation and phenotypic characterization of the MSCs expanded with FBS and PLs were determined. Results: MSCs treated with culture media containing FBS and PB-PL, were successfully isolated and expanded, whereas MSCs treated with CB-PL could not be maintained in culture. Furthermore, the MRM analysis yielded differences in growth factor levels between PB-PL and CB-PL. In addition, the MSCs were successfully expanded with FBS and PB-PL and exhibited tri-lineage differentiation and stable phenotypic characteristics. Conclusion: PB-PL could be used as an alternative additive for the production of MSCs culture medium applied to xenogeneic-free expansion and maintenance of MSCs in large scale clinical studies.

Collagenase Impacts the Quantity and Quality of Native Mesenchymal Stem/Stromal Cells Derived during Processing of Umbilical Cord Tissue

Enzymes are commonly used as a biochemical means to liberate cells from a host of tissues for use in in vitro studies and/or in vivo transplantations. However, very little understanding exists of the biological and functional effects that enzymes have on cells during the process of releasing the native cells from a given tissue. One specific reason for this is that no technology has existed as a nonenzymatic control to compare baseline biology and function for a given processed tissue. We have developed a sterile, onetime use, disposable system (referred to as the AuxoCell Processing System or AC:Px®) that allows for processing of solid tissue in a closed, standardized system using mechanical means to liberate cells without the need and/or use of any biochemical, enzymatic digestion. In this report, for the first time, we directly compare the cellular outputs derived from processing the same umbilical cord tissue (UCT) in the presence and absence of collagenase. In the presence of collagenase, we observed on average, approximately a 2.7-fold reduction in native mesenchymal stem/stromal cell (MSC) yields and a reduction in MSC-specific markers CD90, CD29, CD105, CD73, CD44, CD36, CD49b, CD49a, CD146, CD295, and CD166 and in endothelial marker CD31. These data directly exhibit that the use of collagenase to process UCT to release cells impacts cell recovery with respect to number and cell surface marker expression and, hence, could affect the in vivo function of the recovered native cellular population.

Comparative analysis of human Wharton's jelly mesenchymal stem cells derived from different parts of the same umbilical cord

Easy isolation, lack of ethical issues, high proliferation, multi-lineage differentiation potential and immunomodulatory properties of umbilical cord (UC)-derived mesenchymal stem cells (MSCs) make them a valuable tool in stem cell research. Recently, Wharton’s jelly (WJ) was proven as the best MSC source among various compartments of UC. However, it is still unclear whether or not Wharton’s jelly-derived MSCs (WJMSCs) from different parts of the whole cord exhibit the same characteristics. There may be varied MSCs present in different parts of WJ throughout the length of the UC. For this purpose, using an explant attachment method, WJMSCs were isolated from three different parts of the UC, mainly present towards the placenta (mother part), the center of the whole cord (central part) and the part attached to the fetus (baby part). WJMSCs from all three parts were maintained in normal growth conditions (10% ADMEM) and analyzed for mesenchymal markers, pluripotent genes, proliferation rate and tri-lineage differentiation potential. All WJMSCs were highly proliferative, positively expressed CD90, CD105, CD73 and vimentin, while not expressing CD34, CD45, CD14, CD19 or HLA-DR, differentiated into adipocytes, osteocytes and chondrocytes and expressed pluripotency markers OCT-4, SOX-2 and NANOG at gene and protein levels. Furthermore, MSCs derived from all the parts were shown to have potency towards hepatocyte-like cell differentiation. Human bone marrow-derived MSCs were used as a positive control. Finally, we conclude that WJMSCs derived from all the parts are valuable sources and can be efficiently used in various fields of regenerative medicine.

A Simple Method to Isolate and Expand Human Umbilical Cord Derived Mesenchymal Stem Cells: Using Explant Method and Umbilical Cord Blood Serum

Background and Objectives

Mesenchymal stem cells (MSCs) are multipotent stem cells that can be isolated from umbilical cords and are therapeutically used because of their ability to differentiate into various types of cells, in addition to their immunosuppressive and anti-inflammatory properties. Fetal bovine serum (FBS), considered as the standard additive when isolating and culturing MSCs, has a major limitation related to its animal origin. Here, we employed a simple and economically efficient protocol to isolate MSCs from human umbilical cord tissues without using digestive enzymes and replacing FBS with umbilical cord blood serum (CBS).

Methods and Results

MSCs were isolated by culturing umbilical cord pieces in CBS or FBS supplemented media. Expansion and proliferation kinetics of cells isolated by explant method in the presence of either FBS or CBS were measured, with morphology and multi-differentiation potential of expanded cells characterized by flow cytometry, RT-PCR, and immunofluorescence. MSCs maintained morphology, immunophenotyping, multi-differentiation potential, and self-renewal ability, with better proliferation rates for cells cultured in CBS compared to FBS supplement media.

Conclusions

We here present a simple, reliable and efficient method to isolate MSCs from umbilical cord tissues, where cells maintained proliferation, differentiation potential and immunophenotyping properties and could be efficiently expanded for clinical applications.

Differentiation of mesenchymal stem cells into neuron-like cells using composite 3D scaffold combined with valproic acid induction

The nervous system has little capacity for self-repair after injury because neurons cannot proliferate owing to lack of suitable microenvironment. Therefore, neural tissue engineering that combines neural stem, scaffolds, and growth factors may improve the chance of restoration of damaged neural tissues. A favorable niche for neural regeneration would be both fibrous and electrically conductive scaffolds. Human Wharton jelly-derived mesenchymal stem cells were seeded on wet-electrospun 3D scaffolds composed of poly lactic acid coated with natural polymers including alginate and gelatin, followed by a multi-wall carbon nanotube coating. The results show that a wet-electrospun poly lactic acid scaffold at a concentration of 15% w/v had higher porosity (above 80%) than other concentrations. Moreover, the coated scaffold supported the growth of human Wharton jelly-derived mesenchymal stem cells in 3D culture, and were incubated for 21 days with 1 mM valproic acid as the inducer resulted in improvement in human Wharton jelly-derived mesenchymal stem cells differentiation into neuron-like cells immunoreactivity to nestin, Map2, and neuron specific enolase (NSE), which were also consistent with reverse transcription polymerase chain reaction (RT-PCR) and quantitive Reverse transcription polymerase chain reaction (qRT-PCR) results. The conclusion is that the 3D composite nanofiber poly lactic acid scaffold improved the transdifferentiation of human Wharton jelly-derived mesenchymal stem cells into neuron-like cells.

Allogeneic Umbilical Cord-Derived Mesenchymal Stem Cells as a Potential Source for Cartilage and Bone Regeneration: An In Vitro Study

Umbilical cord (UC) may represent an attractive cell source for allogeneic mesenchymal stem cell (MSC) therapy. The aim of this in vitro study is to investigate the chondrogenic and osteogenic potential of UC-MSCs grown onto tridimensional scaffolds, to identify a possible clinical relevance for an allogeneic use in cartilage and bone reconstructive surgery. Chondrogenic differentiation on scaffolds was confirmed at 4 weeks by the expression of sox-9 and type II collagen; low oxygen tension improved the expression of these chondrogenic markers. A similar trend was observed in pellet culture in terms of matrix (proteoglycan) production. Osteogenic differentiation on bone-graft-substitute was also confirmed after 30 days of culture by the expression of osteocalcin and RunX-2. Cells grown in the hypertrophic medium showed at 5 weeks safranin o-positive stain and an increased CbFa1 expression, confirming the ability of these cells to undergo hypertrophy. These results suggest that the UC-MSCs isolated from minced umbilical cords may represent a valuable allogeneic cell population, which might have a potential for orthopaedic tissue engineering such as the on-demand cell delivery using chondrogenic, osteogenic, and endochondral scaffold. This study may have a clinical relevance as a future hypothetical option for allogeneic single-stage cartilage repair and bone regeneration.

Isolation, cultivation, and characterization of human mesenchymal stem cells

Mesenchymal stem cells (MSC) exhibit a high self-renewal capacity, multilineage differentiation potential and immunomodulatory properties. This set of exceptional features makes them an attractive tool for research and clinical application. However, MSC are far from being a uniform cell type, which makes standardization difficult. The exact properties of human MSC (hMSC) can vary greatly depending on multiple parameters including tissue source, isolation method and medium composition. In this review we address the most important influence factors. We highlight variations in the differentiation potential of MSC from different tissue sources. Furthermore, we compare enzymatic isolation strategies with explants cultures focusing on adipose tissue and umbilical cords as two relevant examples. Additionally, we address effects of medium composition and serum supplementation on MSC expansion and differentiation. The lack of standardized methods for hMSC isolation and cultivation mandates careful evaluation of different protocols regarding efficiency and cell quality. MSC characterization based on a set of minimal criteria defined by the International Society for Cellular Therapy is a widely accepted practice, and additional testing for MSC functionality can provide valuable supplementary information. The MSC secretome has been identified as an important signaling mechanism to affect other cells. In this context, extracellular vesicles (EVs) are attracting increasing interest. The thorough characterization of MSC-derived EVs and their interaction with target cells is a crucial step toward a more complete understanding of MSC-derived EV functionality. Here, we focus on flow cytometric approaches to characterize free as well as cell bound EVs and address potential differences in the bioactivity of EVs derived from stem cells from different sources. © 2017 International Society for Advancement of Cytometry.

Isolation and Characterization of Mesenchymal Stromal Cells from Human Umbilical Cord and Fetal Placenta

The human umbilical cord (UC) and placenta are non-invasive, primitive and abundant sources of mesenchymal stromal cells (MSCs) that have increasingly gained attention because they do not pose any ethical or moral concerns. Current methods to isolate MSCs from UC yield low amounts of cells with variable proliferation potentials. Since UC is an anatomically-complex organ, differences in MSC properties may be due to the differences in the anatomical regions of their isolation. In this study, we first dissected the cord/placenta samples into three discrete anatomical regions: UC, cord-placenta junction (CPJ), and fetal placenta (FP). Second, two distinct zones, cord lining (CL) and Wharton's jelly (WJ), were separated. The explant culture technique was then used to isolate cells from the four sources. The time required for the primary culture of cells from the explants varied depending on the source of the tissue. Outgrowth of the cells occurred within 3 - 4 days of the CPJ explants, whereas growth was observed after 7 - 10 days and 11 - 14 days from CL/WJ and FP explants, respectively. The isolated cells were adherent to plastic and displayed fibroblastoid morphology and surface markers, such as CD29, CD44, CD73, CD90, and CD105, similarly to bone marrow (BM)-derived MSCs. However, the colony-forming efficiency of the cells varied, with CPJ-MSCs and WJ-MSCs showing higher efficiency than BM-MSCs. MSCs from all four sources differentiated into adipogenic, chondrogenic, and osteogenic lineages, indicating that they were multipotent. CPJ-MSCs differentiated more efficiently in comparison to other MSC sources. These results suggest that the CPJ is the most potent anatomical region and yields a higher number of cells, with greater proliferation and self-renewal capacities in vitro. In conclusion, the comparative analysis of the MSCs from the four sources indicated that CPJ is a more promising source of MSCs for cell therapy, regenerative medicine, and tissue engineering.

Explant culture: An advantageous method for isolation of mesenchymal stem cells from human tissues

Mesenchymal stem cell (MSC) research progressively moves towards clinical phases. Accordingly, a wide range of different procedures were presented in the literature for MSC isolation from human tissues; however, there is not yet any close focus on the details to offer precise information for best method selection. Choosing a proper isolation method is a critical step in obtaining cells with optimal quality and yield in companion with clinical and economical considerations. In this concern, current review widely discusses advantages of omitting proteolysis step in isolation process and presence of tissue pieces in primary culture of MSCs, including removal of lytic stress on cells, reduction of in vivo to in vitro transition stress for migrated/isolated cells, reduction of price, processing time and labour, removal of viral contamination risk, and addition of supporting functions of extracellular matrix and released growth factors from tissue explant. In next sections, it provides an overall report of technical highlights and molecular events of explant culture method for isolation of MSCs from human tissues including adipose tissue, bone marrow, dental pulp, hair follicle, cornea, umbilical cord and placenta. Focusing on informative collection of molecular and methodological data about explant methods can make it easy for researchers to choose an optimal method for their experiments/clinical studies and also stimulate them to investigate and optimize more efficient procedures according to clinical and economical benefits.

Optimization of human mesenchymal stem cell isolation from synovial membrane: Implications for subsequent tissue engineering effectiveness

Synovium-derived mesenchymal stem cells (SDMSCs) are one of the most suitable sources for cartilage repair because of their chondrogenic and proliferative capacity. However, the isolation methods for SDMSCs have not been extensively characterized. Thus, our aim in this study was to optimize the processes of enzymatic isolation followed by culture expansion in order to increase the number of SDMSCs obtained from the original tissue. Human synovium obtained from 18 donors (1.5 g/donor) was divided into three aliquots. The samples were minced and subjected to collagenase digestion, followed by different procedures: Group 1, Tissue fragments were removed by filtering followed by removing floating tissue; Group 2, No filtering. Only floating fragments were removed; Group 3, No fragments were removed. Subsequently, each aliquot was sub-divided into two density subgroups with half. In Group 1, the cell-containing media was plated either at high (5000 cells/cm²) or low density (1000 cells/cm²). In Groups 2 and 3, the media containing cells and tissue was plated onto the same number of culture dishes as used in Group 1, either at high or low density. At every passage, the cells plated at high density were consistently re-plated at high and those plated at low density were likewise. The expanded cell yields at day 21 following cell isolation were calculated. These cell populations were then evaluated for their osteogenic, adipogenic, and chondrogenic differentiation capabilities. The final cell yields per 0.25 g tissue in Group 1 were similar at high and low density, while those in Groups 2 and 3 exhibited higher when cultured at low density. The cell yields at low density were 0.7 ± 1.2 × 10⁷ in Group 1, 5.7 ± 1.1 × 10⁷ in Group 2, 4.3 ± 1.2 × 10⁷ in Group 3 (Group 1 vs Groups 2 and 3, p < 0.05). In addition, the cells obtained in each low density subgroup exhibited equivalent osteogenic, adipogenic, and chondrogenic differentiation. Thus, it was evident that filtering leads to a loss of cells and does not affect the differentiation capacities. In conclusion, exclusion of a filtering procedure could contribute to obtain higher number of SDMSCs from synovial membrane without losing differentiation capacities.

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The processes of enzymatic isolation of MSCs from synovium have been optimized.

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Exclusion of filtering the undigested synovial debris provides higher number of SDMSCs.

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Exclusion of filtering the undigested synovial debris provides higher number of MSCs.

Embryoid Body-Explant Outgrowth Cultivation from Induced Pluripotent Stem Cells in an Automated Closed Platform

Automation of cell culture would facilitate stable cell expansion with consistent quality. In the present study, feasibility of an automated closed-cell culture system "P 4C S" for an embryoid body- (EB-) explant outgrowth culture was investigated as a model case for explant culture. After placing the induced pluripotent stem cell- (iPSC-) derived EBs into the system, the EBs successfully adhered to the culture surface and the cell outgrowth was clearly observed surrounding the adherent EBs. After confirming the outgrowth, we carried out subculture manipulation, in which the detached cells were simply dispersed by shaking the culture flask, leading to uniform cell distribution. This enabled continuous stable cell expansion, resulting in a cell yield of 3.1 × 10(7). There was no evidence of bacterial contamination throughout the cell culture experiments. We herewith developed the automated cultivation platform for EB-explant outgrowth cells.

Wharton's Jelly-Derived Mesenchymal Stromal Cells and Fibroblast-Derived Extracellular Matrix Synergistically Activate Apoptosis in a p21-Dependent Mechanism in WHCO1 and MDA MB 231 Cancer Cells In Vitro

The tumour microenvironment plays a crucial role in tumour progression and comprises tumour stroma which is made up of different cell types and the extracellular matrix (ECM). Mesenchymal stromal cells (MSCs) are part of the tumour stroma and may have conflicting effects on tumour growth. In this study we investigated the effect of Wharton's Jelly-derived MSCs (WJ-MSCs) and a fibroblast-derived ECM (fd-ECM) on esophageal (WHCO1) and breast (MDA MB 231) cancer cells in vitro. Both WJ-MSCs and the fd-ECM, alone or in combination, downregulate PCNA, cyclin D1, Bcl-2, Bcl-xL, and MMPs and upregulate p53 and p21. p21 induction resulted in G2 phase cell cycle arrest and induced apoptosis in vitro. Our data suggest that p21 induction is via p53-dependent and p53-independent mechanisms in WHCO1 and MDA MB 231 cells, respectively. Vascular endothelial growth factor, Akt, and Nodal pathways were downregulated in cancer cells cocultured with WJ-MSCs. We also demonstrate that WJ-MSCs effects on cancer cells appear to be short-lived whilst the fd-ECM effect is long-lived. This study shows the influence of tumour microenvironment on cancer cell behaviour and provides alternative therapeutic targets for potential regulation of tumour cells.

Wharton's jelly derived mesenchymal stem cells: future of regenerative medicine? Recent findings and clinical significance

Around 5 million annual births in EU and 131 million worldwide give a unique opportunity to collect lifesaving Wharton's jelly derived mesenchymal stem cells (WJ-MSC). Evidences that these cells possess therapeutic properties are constantly accumulating. Collection of WJ-MSC is done at the time of delivery and it is easy and devoid of side effects associated with collection of adult stem cells from bone marrow or adipose tissue. Likewise, their rate of proliferation, immune privileged status, lack of ethical concerns, nontumorigenic properties make them ideal for both autologous and allogeneic use in regenerative medicine applications. This review provides an outline of the recent findings related to WJ-MSC therapeutic effects and possible advantage they possess over MSC from other sources. Results of first clinical trials conducted to treat immune disorders are highlighted.