Human multipotent adult progenitor cell-conditioned medium improves wound healing through modulating inflammation and angiogenesis in mice

Advancing wound healing by hydrogel-based dressings loaded with cell-conditioned medium: a systematic review

BACKGROUND

Wound healing represents a complex biological process, critically important in clinical practice due to its direct implication in a patient's recovery and quality of life. Conservative wound management frequently falls short in providing an ideal environment for the optimal tissue regeneration, often resulting in extended healing periods and elevated risk of infection and other complications. The emerging biomaterials, particularly hydrogels, have shown substantial promise in addressing these challenges by offering properties such as biocompatibility, biodegradability, and the ability to cure wound environment. Recent advancements have highlighted the therapeutic potential of integrating cell-derived conditioned medium (CM) into hydrogel matrices. Cell-derived CM represents a rich array of bioactive molecules, demonstrating significant efficacy in modulating cellular activities crucial for wound healing, including cellular proliferation, migration, and angiogenesis.

METHODS

The methodology of this review adheres to the standards set by the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. The review includes a selection of studies published within the last five years, focusing on in vivo experiments involving various types of skin injuries treated with topically applied hydrogels loaded with CM (H-CM). The search strategy refers to the PICO framework and includes the assessment of study quality by CAMARADES tool.

RESULTS

The systematic review represents a detailed evaluation of H-CM dressings wound healing efficiency based on the experimental results of cell-based assays and animal wound models. The study targets to reveal wound healing capacity of H-CM dressings, and provides a comparative data analysis, limitations of methods and discussions of H-CM role in advancing the wound healing therapy.

CONCLUSIONS

The data presented demonstrate that H-CM is a promising material for advanced wound healing and regenerative medicine. These dressings possess proved in vitro/in vivo efficacy that highlights their strong clinical potential and paves the way to further investigations of H-CM formulations within clinical trials.

Human Umbilical Cord Mesenchymal Stem Cells Promote Anti-Inflammation and Angiogenesis by Targeting Macrophages in a Rat Uterine Scar Model

BACKGROUND

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have demonstrated efficacy in repairing uterine scars, although the underlying mechanisms remain unclear.

METHODS

Uterine injury was surgically induced in a rat model, followed by immediate transplantation of 5 × 10 ^ 5 hUC-MSCs to each side of the uterus. Uterine morphology was evaluated at days 14 and 30 using HE and Masson staining. Immunohistochemistry assessed macrophage polarization, angiogenesis and endometrial receptivity in the endometrium. Additionally, the regulatory effects of hUC-MSCs on macrophage polarization were explored through coculture. qRT-PCR quantified the expression of anti-inflammatory (IL10 and Arg1) and pro-inflammatory (iNOS and TNF-α) factors. Western blotting evaluated CD163 expression.

RESULTS

Transplantation of hUC-MSCs promoted the healing of uterine injuries and tissue regeneration while inhibiting tissue fibrosis. Immunohistochemistry at days 14 and 30 post-transplantation demonstrated the polarization of macrophages toward the M2 phenotype in the uterine injury area in the presence of hUC-MSCs. Furthermore, hUC-MSC transplantation improved angiogenesis and endometrial receptivity in the uterine injury rat model, associated with increased IL10 expression. hUC-MSC-induced angiogenesis can be resisted by depleted macrophages. In vitro coculture experiments further demonstrated that hUC-MSCs promoted IL10 expression in macrophages while suppressing TNF-α and iNOS expression. Western blotting showed enhanced CD163 expression in macrophages following hUC-MSC treatment.

CONCLUSIONS

hUC-MSCs contribute to the healing of uterine injuries by targeting macrophages to promote angiogenesis and the expression of anti-inflammatory factors.

The Phoenix of stem cells: pluripotent cells in adult tissues and peripheral blood

Pluripotent stem cells are defined as cells that can generate cells of lineages from all three germ layers, ectoderm, mesoderm, and endoderm. On the contrary, unipotent and multipotent stem cells develop into one or more cell types respectively, but their differentiation is limited to the cells present in the tissue of origin or, at most, from the same germ layer. Multipotent and unipotent stem cells have been isolated from a variety of adult tissues, Instead, the presence in adult tissues of pluripotent stem cells is a very debated issue. In the early embryos, all cells are pluripotent. In mammalians, after birth, pluripotent cells are maintained in the bone-marrow and possibly in gonads. In fact, pluripotent cells were isolated from marrow aspirates and cord blood and from cultured bone-marrow stromal cells (MSCs). Only in few cases, pluripotent cells were isolated from other tissues. In addition to have the potential to differentiate toward lineages derived from all three germ layers, the isolated pluripotent cells shared other properties, including the expression of cell surface stage specific embryonic antigen (SSEA) and of transcription factors active in the early embryos, but they were variously described and named. However, it is likely that they are part of the same cell population and that observed diversities were the results of different isolation and expansion strategies. Adult pluripotent stem cells are quiescent and self-renew at very low rate. They are maintained in that state under the influence of the "niche" inside which they are located. Any tissue damage causes the release in the blood of inflammatory cytokines and molecules that activate the stem cells and their mobilization and homing in the injured tissue. The inflammatory response could also determine the dedifferentiation of mature cells and their reversion to a progenitor stage and at the same time stimulate the progenitors to proliferate and differentiate to replace the damaged cells. In this review we rate articles reporting isolation and characterization of tissue resident pluripotent cells. In the attempt to reconcile observations made by different authors, we propose a unifying picture that could represent a starting point for future experiments.

A Review of the Evidence for Tryptophan and the Kynurenine Pathway as a Regulator of Stem Cell Niches in Health and Disease

Stem cells are ubiquitously found in various tissues and organs in the body, and underpin the body's ability to repair itself following injury or disease initiation, though repair can sometimes be compromised. Understanding how stem cells are produced, and functional signaling systems between different niches is critical to understanding the potential use of stem cells in regenerative medicine. In this context, this review considers kynurenine pathway (KP) metabolism in multipotent adult progenitor cells, embryonic, haematopoietic, neural, cancer, cardiac and induced pluripotent stem cells, endothelial progenitor cells, and mesenchymal stromal cells. The KP is the major enzymatic pathway for sequentially catabolising the essential amino acid tryptophan (TRP), resulting in key metabolites including kynurenine, kynurenic acid, and quinolinic acid (QUIN). QUIN metabolism transitions into the adjoining de novo pathway for nicotinamide adenine dinucleotide (NAD) production, a critical cofactor in many fundamental cellular biochemical pathways. How stem cells uptake and utilise TRP varies between different species and stem cell types, because of their expression of transporters and responses to inflammatory cytokines. Several KP metabolites are physiologically active, with either beneficial or detrimental outcomes, and evidence of this is presented relating to several stem cell types, which is important as they may exert a significant impact on surrounding differentiated cells, particularly if they metabolise or secrete metabolites differently. Interferon-gamma (IFN-γ) in mesenchymal stromal cells, for instance, highly upregulates rate-limiting enzyme indoleamine-2,3-dioxygenase (IDO-1), initiating TRP depletion and production of metabolites including kynurenine/kynurenic acid, known agonists of the Aryl hydrocarbon receptor (AhR) transcription factor. AhR transcriptionally regulates an immunosuppressive phenotype, making them attractive for regenerative therapy. We also draw attention to important gaps in knowledge for future studies, which will underpin future application for stem cell-based cellular therapies or optimising drugs which can modulate the KP in innate stem cell populations, for disease treatment.

Multipotent/pluripotent stem cell populations in stromal tissues and peripheral blood: exploring diversity, potential, and therapeutic applications

The concept of "stemness" incorporates the molecular mechanisms that regulate the unlimited self-regenerative potential typical of undifferentiated primitive cells. These cells possess the unique ability to navigate the cell cycle, transitioning in and out of the quiescent G0 phase, and hold the capacity to generate diverse cell phenotypes. Stem cells, as undifferentiated precursors endow with extraordinary regenerative capabilities, exhibit a heterogeneous and tissue-specific distribution throughout the human body. The identification and characterization of distinct stem cell populations across various tissues have revolutionized our understanding of tissue homeostasis and regeneration. From the hematopoietic to the nervous and musculoskeletal systems, the presence of tissue-specific stem cells underlines the complex adaptability of multicellular organisms. Recent investigations have revealed a diverse cohort of non-hematopoietic stem cells (non-HSC), primarily within bone marrow and other stromal tissue, alongside established hematopoietic stem cells (HSC). Among these non-HSC, a rare subset exhibits pluripotent characteristics. In vitro and in vivo studies have demonstrated the remarkable differentiation potential of these putative stem cells, known by various names including multipotent adult progenitor cells (MAPC), marrow-isolated adult multilineage inducible cells (MIAMI), small blood stem cells (SBSC), very small embryonic-like stem cells (VSELs), and multilineage differentiating stress enduring cells (MUSE). The diverse nomenclatures assigned to these primitive stem cell populations may arise from different origins or varied experimental methodologies. This review aims to present a comprehensive comparison of various subpopulations of multipotent/pluripotent stem cells derived from stromal tissues. By analysing isolation techniques and surface marker expression associated with these populations, we aim to delineate the similarities and distinctions among stromal tissue-derived stem cells. Understanding the nuances of these tissue-specific stem cells is critical for unlocking their therapeutic potential and advancing regenerative medicine. The future of stem cells research should prioritize the standardization of methodologies and collaborative investigations in shared laboratory environments. This approach could mitigate variability in research outcomes and foster scientific partnerships to fully exploit the therapeutic potential of pluripotent stem cells.

Combination of stem cell-derived secretome from human exfoliated deciduous teeth with Yemeni Sidr honey on cell viability and migration: an in vitro study

INTRODUCTION

Bone diseases have a profound global impact, especially when the body's innate regenerative capacity falls short in the face of extensive damage. Stem cells from human exfoliated deciduous teeth (SHEDs), discovered in 2003, offer a promising solution for tissue repair, as they self-renew naturally and are easily obtainable. Mesenchymal stem cells (MSCs), including SHEDs, are believed to promote tissue regeneration by releasing growth factors, collectively known as the secretome.

AIMS

This study explored the potential of combining SHED-derived secretome with Yemeni Sidr honey to improve osteoblast and fibroblast cell viability and migration.

MATERIALS AND METHODS

The experiment involved treating cell cultures of two types of rat cell lines - 7F2 osteoblast and BHK-21 fibroblast immortalized cells - with SHED-derived secretome and Yemeni Sidr honey. After the treatment, cell viability was measured using the MTT assay, which calculates OD at 590 nm. Additionally, the scratch assay was conducted to evaluate cell migration, and ImageJ software was used for data processing.

RESULTS

The findings indicated that combining SHED-derived secretome and Yemeni Sidr honey enhanced osteoblast and fibroblast cell viability and migration. Furthermore, the study highlighted the difference in the stimulative potential of SHED-derived secretome, Yemeni Sidr honey, and their combination, on the viability and migration of the cultured cells.

CONCLUSION

The research concludes that combining SHED-derived secretome with Yemeni Sidr honey has the potential to promote cell viability and migration in in-vitro settings. The synergistic application of these substances has been found to be more effective -when combined in a dose-dependent manner- than their counterparts. Overall, the current study serves as a foundation for further investigations to establish if the explored substance has any useful clinical applications.

Encapsulation of HaCaT Secretome for Enhanced Wound Healing Capacity on Human Dermal Fibroblasts

In the epidermal and dermal layers of the skin, diverse cell types are reconstituted during the wound healing process. Delays or failures in wound healing are a major issue in skin therapy because they prevent the normal structure and function of wounded tissue from being restored, resulting in ulceration or other skin abnormalities. Human immortalized keratinocytes (HaCAT) cells are a spontaneously immortalized human keratinocyte cell line capable of secreting many bioactive chemicals (a secretome) that stimulate skin cell proliferation, rejuvenation, and regeneration. In this study, the HaCaT secretome was encapsulated with polyesters such as poly (lactic-co-glycolic acid) (PLGA) and cassava starch in an effort to maximize its potential. According to the estimated mechanism of the HaCaT secretome, all treatments were conducted on immortalized dermal fibroblast cell lines, a model of wound healing. Encapsulation of HaCaT secretome and cassava starch enhanced the effectiveness of cell proliferation, migration, and anti-aging. On the other hand, the levels of reactive oxygen species (ROS) were lowered, activating antioxidants in immortalized dermal fibroblast cells. The HaCaT secretome induced in a dose-dependent manner the expression of antioxidant-associated genes, including SOD, CAT, and GPX. Six cytokines, including CCL2 and MCP-1, influenced immunoregulatory and inflammatory processes in cultured HaCAT cells. HaCaT secretome encapsulated in cassava starch can reduce ROS buildup by boosting antioxidant to stimulate wound healing. Hence, the HaCaT secretome may have a new chance in the cosmetics business to develop components for wound prevention and healing.

Delivery of multipotent adult progenitor cells via a functionalized plasma polymerized surface accelerates healing of murine diabetic wounds

Introduction: Stem cell therapies have been investigated as potential treatment modalities for chronic wounds however there has been limited success to date. Multipotent Adult Progenitor Cells (MAPCs©) have been identified as having potential as an allogenic stem cell product due to their high population doubling number and their characteristic dampening of T-cell proliferation. This helps to prevent autoimmunity and graft/cell rejection. Methods: We have developed a dressing, consisting of medical grade silicone coated with a heptylamine plasma polymer, which supports the growth and transfer of MAPCs to skin. To determine if the dressing can deliver functional stem cells into diabetic wounds, they were loaded with MAPCs and then placed over excisional wounds in both normal and diabetic mice. Results and discussion: Accelerated healing was observed in both the normal and diabetic wounds with wound gape being significantly smaller at day 3 when compared to controls. Wound analysis showed that treatment with the MAPC dressings dampened the inflammatory response with reduced numbers of neutrophils and macrophages observed. Additionally, an increase in pro-angiogenic VEGF and CD31 positive endothelial cells was observed indicating improved new blood vessel formation. The MAPC dressings had no effect on fibrosis with collagen I and III being equally affected in both control and treated wounds. Overall, the functionalized MAPC dressings improve healing responses particularly in diabetic mice with impaired healing responses and therefore, show potential for development as an advanced therapeutic approach for the treatment of chronic diabetic wounds.

Therapeutic Application of Cell Secretomes in Cutaneous Wound Healing

Although the application of stem cells to chronic wounds emerged as a candidate therapy in the previous century, the mechanism of action remains unclear. Recent evidence has implicated secreted paracrine factors in the regenerative properties of cell-based therapies. In the last two decades, considerable research advances involving the therapeutic potential of stem cell secretomes have expanded the scope of secretome-based therapies beyond stem cell populations. In this study, we review the modes of action of cell secretomes in wound healing, important preconditioning strategies for enhancing their therapeutic efficacy, and clinical trials on secretome-based wound healing.

The Potential of MSC-Based Cell-Free Therapy in Wound Healing-A Thorough Literature Review

A wound is an interruption of the normal anatomic structure and function of the skin, which is critical in protecting against foreign pathogens, regulating body temperature and water balance. Wound healing is a complex process involving various phases, including coagulation, inflammation, angiogenesis, re-epithelialization, and re-modeling. Factors such as infection, ischemia, and chronic diseases such as diabetes can compromise wound healing, leading to chronic and refractory ulcers. Mesenchymal stem cells (MSCs) have been used to treat various wound models due to their paracrine activity (secretome) and extracellular vehicles (exosomes) that contain several molecules, including long non-coding RNAs (lncRNAs), micro-RNAs (miRNAs), proteins, and lipids. Studies have shown that MSCs-based cell-free therapy using secretome and exosomes has great potential in regenerative medicine compared to MSCs, as there are fewer safety concerns. This review provides an overview of the pathophysiology of cutaneous wounds and the potential of MSCs-based cell-free therapy in each phase of wound healing. It also discusses clinical studies of MSCs-based cell-free therapies.

Retrospectives on Three Decades of Safe Clinical Experience with Allogeneic Dermal Progenitor Fibroblasts: High Versatility in Topical Cytotherapeutic Care

Allogeneic dermal progenitor fibroblasts constitute cytotherapeutic contenders for modern cutaneous regenerative medicine. Based on advancements in the relevant scientific, technical, and regulatory fields, translational developments have slowly yet steadily led to the clinical application of such biologicals and derivatives. To set the appropriate general context, the first aim of this study was to provide a current global overview of approved cell and gene therapy products, with an emphasis on cytotherapies for cutaneous application. Notable advances were shown for North America, Europe, Iran, Japan, and Korea. Then, the second and main aim of this study was to perform a retrospective analysis on the various applications of dermal progenitor fibroblasts and derivatives, as clinically used under the Swiss progenitor cell transplantation program for the past three decades. Therein, the focus was set on the extent and versatility of use of the therapies under consideration, their safety parameters, as well as formulation options for topical application. Quantitative and illustrative data were summarized and reported for over 300 patients treated with various cell-based or cell-derived preparations (e.g., progenitor biological bandages or semi-solid emulsions) in Lausanne since 1992. Overall, this study shows the strong current interest in biological-based approaches to cutaneous regenerative medicine from a global developmental perspective, as well as the consolidated local clinical experience gathered with a specific and safe allogeneic cytotherapeutic approach. Taken together, these current and historical elements may serve as tangible working bases for the further optimization of local and modern translational pathways for the provision of topical cytotherapeutic care.

Cell Secretome Strategies for Controlled Drug Delivery and Wound-Healing Applications

There is significant interest in using stem cells in the management of cutaneous wounds. However, potential safety, efficacy, and cost problems associated with whole-cell transplantation hinder their clinical application. Secretome, a collective of mesenchymal stem-cell-stored paracrine factors, and immunomodulatory cytokines offer therapeutic potential as a cell-free therapy for the treatment of cutaneous wounds. This review explores the possibility of secretome as a treatment for cutaneous wounds and tissue regeneration. The review mainly focuses on in vitro and in vivo investigations that use biomaterials and secretome together to treat wounds, extend secretome retention, and control release to preserve their biological function. The approaches employed for the fabrication of biomaterials with condition media or extracellular vesicles are discussed to identify their future clinical application in wound treatment.

In vitro study of the mesenchymal stem cells-conditional media role in skin wound healing process: A systematic review

Mesenchymal stromal cell (MSC)-conditioned medium (CM) offers a potential opportunity in the skin wound healing treatment. In this systematic review, an overview of the knowledge on this topic has been provided. A multistep search of the PubMed, Scopus and Science Direct database has been performed to identify papers on MSCs-conditional media used in skin wound healing. Eligibility checks were performed based upon predefined selection criteria. Of the 485 articles initially identified, consequently, only 96 articles apparently related to MSC-conditional media were initially assessed for eligibility. Finally, the 32 articles, strictly regarding the in vitro use of MSCs-conditional media in skin wounds, were analysed. The information analysed highlights the efficacy of MSCs-conditional media on skin wound healing in vitro models. The outcome of this review may be used to guide pre-clinical and clinical studies on the role of MSCs-conditional media in skin wound healing.

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

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

Mesenchymal Stem Cell Secretome for Dermatology Application: A Review

Secretome, also known as conditioned medium, is a secreted molecule from mesenchymal stem cells (MSCs) that has a variety of biological activities that can be used in various therapies, especially on the skin applications. A lack of conventional therapies makes secretome as a promising alternative therapy. The presence of growth factors, cytokines, and extracellular vesicles including microvesicles and exosomes in secretome has been widely reported, which serves in improving the proliferation and migration of cells to help in skin regeneration. Therefore, we were able to optimize the use of this secretome in a well-needed special review related to its work in addressing various skin problems. So, in this article, we discussed the benefits and biological activity of secretome on the skin application. This review was compiled based on the approval of several sites, such as Scopus, PubMed, Science Direct, and Google Scholar with the terms "MSC secretome for skin," "secretome for skin," "secretome dermatology," "secretome conditioned medium for skin," "secretome conditioned medium for skin wound," "secretome conditioned medium for aging," "secretome conditioned medium for hair growth," and "secretome conditioned medium for psoriasis." A total of 215 articles were collected for selection, of which 90 articles were used. Based on the results, it was concluded that secretome has a variety of useful activities to regenerate and repair tissue damage that have not been used on the skin, such as for wound healing, photoprotection, promotion of hair growth, psoriasis treatment, and other application as antimicrobial.

Mesenchymal Stromal Cell-Conditioned Medium for Skin Diseases: A Systematic Review

The skin is the largest organ of the human body, and its dysfunction is related to many diseases. There is a need to find new potential effective therapies for some skin conditions such as inflammatory diseases, wound healing, or hair restoration. Mesenchymal stromal cell (MSC)-conditioned medium (CM) provides a potential opportunity in the treatment of skin disease. Thus, the objective of this review is to evaluate the uses of MSC-CM for treating skin diseases in both animal and human models. A systematic review was conducted regarding the use of MSC-CM for treating skin conditions. One hundred one studies were analyzed. MSC-CM was evaluated in wound healing (55), hypertrophic scars (9), flap reperfusion (4), hair restoration (15), skin rejuvenation (15), and inflammatory skin diseases (3). MSC-CM was obtained from different MSC sources, mainly adipose tissue, bone marrow, and umbilical cord blood. MSC-CM was tested intravenously, intraperitoneally, subcutaneously, intradermally or intralesionally injected or topically applied. MSC-CM was used in both animals and humans. MSC-CM improved wound healing, hair restoration, skin rejuvenation, atopic dermatitis, and psoriasis in both animals and humans. MSC-CM also decreased hypertrophic scars and flap ischemia in animal models. In conclusion, MSC-CM is a promising therapy for skin conditions. Further studies are needed to corroborate safety and effectiveness and to standardize CM manufacturing.

Mesenchymal Stem Cells as a Cornerstone in a Galaxy of Intercellular Signals: Basis for a New Era of Medicine

Around 40% of the population will suffer at some point in their life a disease involving tissue loss or an inflammatory or autoimmune process that cannot be satisfactorily controlled with current therapies. An alternative for these processes is represented by stem cells and, especially, mesenchymal stem cells (MSC). Numerous preclinical studies have shown MSC to have therapeutic effects in different clinical conditions, probably due to their mesodermal origin. Thereby, MSC appear to play a central role in the control of a galaxy of intercellular signals of anti-inflammatory, regenerative, angiogenic, anti-fibrotic, anti-oxidative stress effects of anti-apoptotic, anti-tumor, or anti-microbial type. This concept forces us to return to the origin of natural physiological processes as a starting point to understand the evolution of MSC therapy in the field of regenerative medicine. These biological effects, demonstrated in countless preclinical studies, justify their first clinical applications, and draw a horizon of new therapeutic strategies. However, several limitations of MSC as cell therapy are recognized, such as safety issues, handling difficulties for therapeutic purposes, and high economic cost. For these reasons, there is an ongoing tendency to consider the use of MSC-derived secretome products as a therapeutic tool, since they reproduce the effects of their parent cells. However, it will be necessary to resolve key aspects, such as the choice of the ideal type of MSC according to their origin for each therapeutic indication and the implementation of new standardized production strategies. Therefore, stem cell science based on an intelligently designed production of MSC and or their derivative products will be able to advance towards an innovative and more personalized medical biotechnology.

Treatment of murine partial thickness scald injuries with multipotent adult progenitor cells decreases inflammation and promotes angiogenesis leading to improved burn injury repair

Stem cells have been shown to have potential as a new therapy for burns and promote wound healing through decreasing inflammation and increasing angiogenesis. Multipotent adult progenitor cells (MAPC® cells) are a subpopulation of bone marrow-derived stem cells with outstanding self-renewal and differentiation capacity. MAPC cells also secrete a wide range of cytokines which can affect cellular activities. This article aimed to examine the effects of MAPC cells treatment on burn injury repair using a mouse model of partial thickness burn injury. The immunomodulatory effect of MAPC cells was investigated in vitro using a simultaneous T-cell proliferation assay. Partial thickness burns were created on the dorsal surface of mice and MAPC cells were administered via intradermal injection to the wound margins 24 h post-burn injury. The burn tissues were analysed macroscopically to determine wound area and histologically assessed to determine wound width and rate of re-epithelialisation. Immunohistochemistry and ELISA were employed to assess cell proliferation, inflammation and angiogenesis and collagen deposition in the burn area. MAPC cells inhibit the proliferation of stimulated T cells in culture. Burns intradermally injected with MAPC cells showed a significant reduction in the macroscopic wound area, histologic wound width and had an increased rate of re-epithelialisation. Immunohistochemistry and ELISA analysis of burn tissues showed dampened inflammation evidenced by a reduction in neutrophilic infiltration and modulation of inflammatory cytokines. Angiogenesis within the burn area was also improved in MAPC cell treated mice. However, no significant effect of MAPC cell treatment was observed on extracellular matrix production. Treatment of burns with MAPC cells improved burn injury repair with reduced time to healing, decreased inflammation and increased angiogenesis. These findings demonstrate the promising effects of MAPC cells on burn injury repair and suggest MAPC cells as a candidate source for clinical cell therapies.

FoxO1 and Wnt/β-catenin signaling pathway: Molecular targets of human amniotic mesenchymal stem cells-derived conditioned medium (hAMSC-CM) in protection against cerebral ischemia/reperfusion injury

Ischemia-reperfusion (I/R) injury has weakened the effects of available treatment options for ischemic stroke. Although conditioned medium obtained from human amniotic mesenchymal stem cells (hAMSC-CM) has been reported to exert protective effect against stroke, detailed knowledge about its possible molecular mechanisms is not still completely available. The present study was designed to investigate whether hAMSC-CM can modulate FoxO1 and Wnt/β-catenin signaling pathway after ischemic stroke to create neuroprotective effects. Middle cerebral artery occlusion (MCAO) model with male Wistar rats was used to evaluate the effects of hAMSC-CM on activities of FoxO1, Wnt/β-catenin signaling pathway, and endogenous antioxidant system and apoptotic cell death. The results demonstrated that induction of MCAO significantly reduced activities of FoxO1, Wnt/β-catenin signaling pathway, and endogenous antioxidant system and enhanced apoptotic cell death (P < 0.05). In addition, treatment by hAMSC-CM immediately after cerebral reperfusion resulted in significantly reduced infarct size and increased activities of FoxO1, Wnt/β-catenin signaling pathway, and restoring endogenous antioxidant system and suppressing apoptotic cell death (P < 0.05). Likewise, increased activity of Wnt/β-catenin signaling pathway resulted in suppressing the neuroinflammation by inhibiting the expression of TNF-α and increasing the expression of IL-10. These findings demonstrate that hAMSC-CM can be considered as an excellent candidate in the treatment of acute ischemic stroke in clinical routine.

Human gingival fibroblast secretome accelerates wound healing through anti-inflammatory and pro-angiogenic mechanisms

Healing of the skin and oral mucosa utilises similar mechanisms of tissue repair, however, scarring and the rate of wound closure is vastly superior in the oral cavity suggesting differences between these two environments. One key difference is the phenotype of dermal fibroblasts compared to fibroblasts of gingival tissues. Human gingival fibroblasts (hGFs) are undifferentiated cells with multi-differentiation and self-renewal capacities. This study aimed to examine if delivering hGFs or their secretome, contained in hGF-conditioned media (hGF-CM), would improve healing of the skin and recapitulate features of oral healing. Human fibroblasts, keratinocytes and endothelial cells were first treated with hGF-CM and showed improved migration, proliferation and angiogenic functions. A significant reduction in macroscopic wound area and histologic dermal wound width, as well as an increased rate of re-epithelialisation, were observed in both hGFs and hGF-CM treated murine excisional wounds. This improvement was associated with reduced inflammation, increased angiogenesis and elevated collagen deposition. These findings demonstrate that treatment of dermal wounds with either hGFs or hGF-CM may provide beneficial gingival-like properties to dermal wounds and may be a potential opportunity for improving healing of the skin.

Mesenchymal Stem Cell Secretome as an Emerging Cell-Free Alternative for Improving Wound Repair

The use of mesenchymal stem cells (MSC) for the treatment of cutaneous wounds is currently of enormous interest. However, the broad translation of cell therapies into clinical use is hampered by their efficacy, safety, manufacturing and cost. MSCs release a broad repertoire of trophic factors and immunomodulatory cytokines, referred to as the MSC secretome, that has considerable potential for the treatment of cutaneous wounds as a cell-free therapy. In this review, we outline the current status of MSCs as a treatment for cutaneous wounds and introduce the potential of the MSC secretome as a cell-free alternative for wound repair. We discuss the challenges and provide insights and perspectives for the future development of the MSC secretome as well as identify its potential clinical translation into a therapeutic treatment.

Multipotent adult progenitor cells grown under xenobiotic-free conditions support vascularization during wound healing

Background

Cell therapy has been evaluated pre-clinically and clinically as a means to improve wound vascularization and healing. While translation of this approach to clinical practice ideally requires the availability of clinical grade xenobiotic-free cell preparations, studies proving the pre-clinical efficacy of the latter are mostly lacking. Here, the potential of xenobiotic-free human multipotent adult progenitor cell (XF-hMAPC®) preparations to promote vascularization was evaluated.

Methods

The potential of XF-hMAPC cells to support blood vessel formation was first scored in an in vivo Matrigel assay in mice. Next, a dose-response study was performed with XF-hMAPC cells in which they were tested for their ability to support vascularization and (epi) dermal healing in a physiologically relevant splinted wound mouse model.

Results

XF-hMAPC cells supported blood vessel formation in Matrigel by promoting the formation of mature (smooth muscle cell-coated) vessels. Furthermore, XF-hMAPC cells dose-dependently improved wound vascularization associated with increasing wound closure and re-epithelialization, granulation tissue formation, and dermal collagen organization.

Conclusions

Here, we demonstrated that the administration of clinical-grade XF-hMAPC cells in mice represents an effective approach for improving wound vascularization and healing that is readily applicable for translation in humans.