Controversies in therapeutic application of mesenchymal stem cell-derived secretome

Milking mesenchymal stem cells: Updated protocols for cell lysate, secretome, and exosome extraction, and comparative analysis of their therapeutic potential

The potential of the cell lysate, secretome, and extracellular vesicles (EVs) of mesenchymal stem cells (MSCs) to modulate the immune response and promote tissue regeneration has positioned them as a promising option for cell-free therapy. Currently, many clinical trials in stem cells-derived EVs and secretome are in progress various diseases and sometimes the results are failing. The major challenge on this roadmap is the lack of a standard extraction method for exosome, secretome, and lysate. The most optimal method for obtaining the secretome of MSCs for clinical utilization involves a comprehensive approach that includes non-destructive collection methods, time optimization, multiple collection rounds, optimization of culture conditions, and quality control measures. Further research and clinical studies are warranted to validate and refine these methods for safe and effective utilization of the MSC exosome, secretome, and lysate in various clinical applications. To address these challenges, it is imperative to establish a standardized and unified methodology to ensure reliable evaluation of these extractions in clinical trials. This review seeks to outline the pros and cons of methods for the preparation of MSCs-derived exosome, and secretome/lysate, and comparative analysis of their therapeutic potential.

Application of Conditioned Medium for In Vitro Modeling and Repair of Respiratory Tissue

Background: The idea of exploring respiratory therapy in vitro predominantly guided by cell-secreted substances has gained ground in recent years. A conditioned medium (CM) consists of protein milieu that contains a diverse spectrum of cytokines, chemokines, angiogenic agents, and growth factors. This review evaluated the efficacy of using CM collected in an in vitro respiratory epithelial model. Methods: Twenty-six papers were included in this review: twenty-one cellular response studies on respiratory secretome application and five studies involving animal research. Results: The CM produced by differentiated cells from respiratory and non-respiratory systems, such as mesenchymal stem cells (MSC), exhibited the similar overall effect of improving proliferation and regeneration. Not only could differentiated cells from respiratory tissues increase proliferation, migration, and attachment, but the CM was also able to protect the respiratory epithelium against cytotoxicity. Most non-respiratory tissue CM was used as a treatment model to determine the effects of the therapy, while only one study used particle-based CM and reported decreased epithelial cell tight junctions, which harmed the epithelial barrier. Conclusion: As it resolves the challenges related to cell development and wound healing while simultaneously generally reducing the danger of immunological compatibility and tumorigenicity, CM might be a potential regenerative therapy in numerous respiratory illnesses. However, additional research is required to justify using CM in respiratory epithelium clinical practice.

Stem Cells for Cancer Therapy: Translating the Uncertainties and Possibilities of Stem Cell Properties into Opportunities for Effective Cancer Therapy

Cancer recurrence and drug resistance following treatment, as well as metastatic forms of cancer, are trends that are commonly encountered in cancer management. Amidst the growing popularity of personalized medicine and targeted therapy as effective cancer treatment, studies involving the use of stem cells in cancer therapy are gaining ground as promising translational treatment options that are actively pursued by researchers due to their unique tumor-homing activities and anti-cancer properties. Therefore, this review will highlight cancer interactions with commonly studied stem cell types, namely, mesenchymal stroma/stem cells (MSC), induced pluripotent stem cells (iPSC), iPSC-derived MSC (iMSC), and cancer stem cells (CSC). A particular focus will be on the effects of paracrine signaling activities and exosomal miRNA interaction released by MSC and iMSCs within the tumor microenvironment (TME) along with their therapeutic potential as anti-cancer delivery agents. Similarly, the role of exosomal miRNA released by CSCs will be further discussed in the context of its role in cancer recurrence and metastatic spread, which leads to a better understanding of how such exosomal miRNA could be used as potential forms of non-cell-based cancer therapy.

Mesenchymal Stem Cell-Derived Secretome: A Potential Therapeutic Option for Autoimmune and Immune-Mediated Inflammatory Diseases

Immune-mediated inflammatory diseases (IMIDs) encompass several entities such as "classic" autoimmune disorders or immune-mediated diseases with autoinflammatory characteristics. Adult stem cells including mesenchymal stem cells (MSCs) are by far the most commonly used type in clinical practice. However, due to the possible side effects of MSC-based treatments, there is an increase in interest in the MSC-secretome (containing large extracellular vesicles, microvesicles, and exosomes) as an alternative therapeutic option in IMIDs. A wide spectrum of MSC-secretome-related biological activities has been proven thus far including anti-inflammatory, anti-apoptotic, and immunomodulatory properties. In comparison with MSCs, the secretome is less immunogenic but exerts similar biological actions, so it can be considered as an ideal cell-free therapeutic alternative. Additionally, since the composition of the MSC-secretome can be engineered, for a future perspective, it could also be viewed as part of a potential delivery system within nanomedicine, allowing us to specifically target dysfunctional cells or tissues. Although many encouraging results from pre-clinical studies have recently been obtained that strongly support the application of the MSC-secretome in IMIDs, human studies with MSC-secretome administration are still in their infancy. This article reviews the immunomodulatory effects of the MSC-secretome in IMIDs and provides insight into the interpretation of its beneficial biological actions.