Stem Cell-Based Therapy and Cell-Free Therapy as an Alternative Approach for Cardiac Regeneration

Human dental follicle cell-derived conditioned media enhance periodontal regeneration by regulating the osteogenic differentiation and inflammation of periodontal ligament stem cells and macrophage polarization

Dental follicle cells (DFCs) derived from the neural crest are promising seed cells for periodontal tissue engineering. This study aimed to investigate whether conditioned media (CM) from human DFCs could regenerate impaired periodontal tissue and the underlying mechanisms. hDFC-derived CM (hDFC-CM) were obtained via ultracentrifugation. In vitro, human periodontal ligament stem cells (hPDLSCs) were treated with hDFC-CM in normal and inflammatory microenvironments, and the cell proliferation, migration, and osteogenic potential were evaluated. We simulated the inflammatory environment with lipopolysaccharide and detected the expression of osteogenic and Wnt/β-catenin signaling pathway-related proteins. The effect of hDFC-CM on the inhibition of hPDLSC inflammation and macrophage polarization was examined. In vivo, the rat periodontitis model was treated with hDFC-CM. Tissue samples were collected after 4 weeks for micro-computed tomography and histological examination. The results of cell counting kit-8 and scratch experiments showed that hDFC-CM significantly enhanced the proliferation and migration capacities of hPDLSCs. hDFC-CM promoted the osteogenic differentiation of hPDLSCs by showing intense alkaline phosphatase and Alizarin Red staining and upregulated osteogenic protein and gene expression. Western blotting also verified that hDFC-CM promotes the osteogenic differentiation of hPDLSCs by regulating the Wnt/β-catenin pathway in an inflammatory environment. In addition, hDFC-CM inhibited hPDLSC inflammation and polarized macrophages from the M1 to M2 phenotype. In vivo, hDFC-CM effectively promoted periodontal tissue regeneration. hDFC-CM enhances periodontal regeneration by regulating the osteogenic differentiation and inflammation of periodontal ligament stem cells and macrophage polarization, which provided new biochemical cues for the treatment of periodontitis.

Mesenchymal Stem Cell Secretome: Potential Applications in Human Infertility Caused by Hormonal Imbalance, External Damage, or Immune Factors

Mesenchymal stem cells (MSCs) are a source of a wide range of soluble factors, including different proteins, growth factors, cytokines, chemokines, and DNA and RNA molecules, in addition to numerous secondary metabolites and byproducts of their metabolism. MSC secretome can be formally divided into secretory and vesicular parts, both of which are very important for intercellular communication and are involved in processes such as angiogenesis, proliferation, and immunomodulation. Exosomes are thought to have the same content and function as the MSCs from which they are derived, but they also have a number of advantages over stem cells, including low immunogenicity, unaltered functional activity during freezing and thawing, and a lack of tumor formation. In addition, MSC pre-treatment with various inflammatory factors or hypoxia can alter their secretomes so that it can be modified into a more effective treatment. Paracrine factors secreted by MSCs improve the survival of other cell populations by several mechanisms, including immunomodulatory (mostly anti-inflammatory) activity and anti-apoptotic activity partly based on Hsp27 upregulation. Reproductive medicine is one of the fields in which this cell-free approach has been extensively researched. This review presents the possible applications and challenges of using MSC secretome in the treatment of infertility. MSCs and their secretions have been shown to have beneficial effects in various models of female and male infertility resulting from toxic damage, endocrine disorders, trauma, infectious agents, and autoimmune origin.

The future of cardiac repair: a review on cell-free nanotherapies for regenerative myocardial infarction

Cardiovascular diseases as myocardial infarction (MI) represent a major cause for morbidity and mortality worldwide. Even though, patients who survive MI are susceptible to high risk of heart failure. This is mainly attributed to the major loss of cardiomyocytes and limited regenerative potential of myocardium. Despite the availability of various cardiovascular drugs, they fail to address the main cause of MI. The optimum therapeutic goal should therefore focus on enhancing cardiac regeneration through cellular and cell-free therapeutic approaches. This review focused on different mechanisms of cardiac regeneration that can be achieved via non-cellular therapeutic modalities. Passive and active targeting of the infarcted myocardium using various nanoparticles that can be loaded with growth factors, drugs or affordable natural products can reduce negative ventricular remodeling, infarct size and the apoptotic rate of cardiomyocytes. In addition, injectable biomaterials-based nanocomposite can be used as a scaffold to support infarcted heart and recruit cells. Innovative affordable and less invasive cell-free approaches can be implemented to enhance cardiac regeneration post MI.

Supramolecular Conductive Hydrogels for Tissue Engineering Applications

Owing to their unique attributes, including reversibility, specificity, directionality, and tunability, supramolecular biomaterials have evolved as an excellent alternative to conventional biomaterials like polymers, ceramics, and metals. Supramolecular hydrogels, in particular, have garnered significant interest because their fibrous architecture, high water content, and interconnected 3D network resemble the extracellular matrix to some extent. Consequently, supramolecular hydrogels have been used to develop biomaterials for tissue engineering. Supramolecular conductive hydrogels combine the advantages of supramolecular soft materials with the electrical properties of metals, making them highly relevant for electrogenic tissue engineering. Given the versatile applications of these hydrogels, it is essential to periodically review high-quality research in this area. In this review, we focus on recent advances in supramolecular conductive hydrogels, particularly their applications in tissue engineering. We discuss the conductive components of these hydrogels and highlight notable reports on their use in cardiac, skin, and neural tissue engineering. Additionally, we outline potential future developments in this field.

An Acellular Platform to Drive Urinary Bladder Tissue Regeneration

Impaired bladder compliance secondary to congenital or acquired bladder dysfunction can lead to irreversible kidney damage. This is managed with surgical augmentation utilizing intestinal tissue, which can cause stone formation, infections, and malignant transformation. Co-seeded bone marrow mesenchymal stem cell (MSC)/CD34+ hematopoietic stem cell (HSPC) scaffolds (PRS) have been successful in regenerating bladder tissue. However, the acquisition of viable cells is challenging in the clinical setting. Here, the regenerative capacity of human MSC/CD34+ co-cultured total condition media (TCM) is compared to media alone in immune-competent rats augmented with PRS following partial cystectomy. Augmented bladders are instilled with media (control, n = 4) or TCM (n = 5) twice a week for 4 weeks. Regenerated tissue is analyzed for smooth muscle, urothelium, vascular, and peripheral nerve regrowth. Urodynamic (UDS) measures are performed pre- and 4 weeks post-augmentation. The results demonstrate that TCM-instilled grafts have greater muscle content, larger average urothelial widths, higher percent vascularization, and more robust neural infiltration post-augmentation. UDS demonstrates greater percent bladder recovery in the TCM group, indicating functional improvement in bladder storage capacity. This study is the first to propose the use of cell-free TCM as an alternative to traditional cell-seeded scaffolds to promote bladder tissue regeneration.

Amniotic membrane, a novel bioscaffold in cardiac diseases: from mechanism to applications

Cardiovascular diseases represent one of the leading causes of death worldwide. Despite significant advances in the diagnosis and treatment of these diseases, numerous challenges remain in managing them. One of these challenges is the need for replacements for damaged cardiac tissues that can restore the normal function of the heart. Amniotic membrane, as a biological scaffold with unique properties, has attracted the attention of many researchers in recent years. This membrane, extracted from the human placenta, contains growth factors, cytokines, and other biomolecules that play a crucial role in tissue repair. Its anti-inflammatory, antibacterial, and wound-healing properties have made amniotic membrane a promising option for the treatment of heart diseases. This review article examines the applications of amniotic membrane in cardiovascular diseases. By focusing on the mechanisms of action of this biological scaffold and the results of clinical studies, an attempt will be made to evaluate the potential of using amniotic membrane in the treatment of heart diseases. Additionally, the existing challenges and future prospects in this field will be discussed.

Mesenchymal Stem Cells and Their Derived Products in Ageing and Diseases

Despite the enormous efforts of the pharmaceutical industry in the generation of new drugs (55 new ones last year) [...].

Stem Cells Derived from Human Exfoliated Deciduous Teeth Functional Assessment: Exploring the Changes of Free Fatty Acids Composition during Cultivation

The metabolic regulation of stemness is widely recognized as a crucial factor in determining the fate of stem cells. When transferred to a stimulating and nutrient-rich environment, mesenchymal stem cells (MSCs) undergo rapid proliferation, accompanied by a change in protein expression and a significant reconfiguration of central energy metabolism. This metabolic shift, from quiescence to metabolically active cells, can lead to an increase in the proportion of senescent cells and limit their regenerative potential. In this study, MSCs from human exfoliated deciduous teeth (SHEDs) were isolated and expanded in vitro for up to 10 passages. Immunophenotypic analysis, growth kinetics, in vitro plasticity, fatty acid content, and autophagic capacity were assessed throughout cultivation to evaluate the functional characteristics of SHEDs. Our findings revealed that SHEDs exhibit distinctive patterns of cell surface marker expression, possess high self-renewal capacity, and have a unique potential for neurogenic differentiation. Aged SHEDs exhibited lower proliferation rates, reduced potential for chondrogenic and osteogenic differentiation, an increasing capacity for adipogenic differentiation, and decreased autophagic potential. Prolonged cultivation of SHEDs resulted in changes in fatty acid composition, signaling a transition from anti-inflammatory to proinflammatory pathways. This underscores the intricate connection between metabolic regulation, stemness, and aging, crucial for optimizing therapeutic applications.