Advances in Immunomodulatory Mechanisms of Mesenchymal Stem Cells-Derived Exosome on Immune Cells in Scar Formation

Advances in locally administered nucleic acid therapeutics

Nucleic acid drugs represent the latest generation of precision therapeutics, holding significant promise for the treatment of a wide range of intractable diseases. Delivery technology is crucial for the clinical application of nucleic acid drugs. However, extrahepatic delivery of nucleic acid drugs remains a significant challenge. Systemic administration often fails to achieve sufficient drug enrichment in target tissues. Localized administration has emerged as the predominant approach to facilitate extrahepatic delivery. While localized administration can significantly enhance drug accumulation at the injection sites, nucleic acid drugs still face biological barriers in reaching the target lesions. This review focuses on non-viral nucleic acid drug delivery techniques utilized in local administration for the treatment of extrahepatic diseases. First, the classification of nucleic acid drugs is described. Second, the current major non-viral delivery technologies for nucleic acid drugs are discussed. Third, the bio-barriers, administration approaches, and recent research advances in the local delivery of nucleic acid drugs for treating lung, brain, eye, skin, joint, and heart-related diseases are highlighted. Finally, the challenges associated with the localized therapeutic application of nucleic acid drugs are addressed.

Mesenchymal stem cell-derived exosomes: an emerging therapeutic strategy for hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (HIRI) severely threatens the success rates of liver surgery and transplantation. Its complex pathological process involves multiple factors such as oxidative stress, inflammatory responses, and ferroptosis, creating an urgent need for new therapeutic strategies. Exosomes derived from mesenchymal stem cells (MSCs) are emerging as a next-generation acellular therapeutic approach. With their outstanding immune-regulatory capabilities, significant reparative functions, and good biocompatibility, they are leading innovations in the field of HIRI treatment. This article provides a systematic comparison of the therapeutic characteristics of MSC-derived exosomes(MSC-EXOs) from four different sources: adipose tissue, bone marrow, umbilical cord, and induced pluripotent stem cells. Although the clinical translation of MSC-EXOs still faces challenges such as variations in isolation methods, large-scale production, and safety assessments, their remarkable therapeutic effects and vast application potential signal the arrival of a new era of precision treatment for HIRI. This review not only provides a comprehensive theoretical foundation to promote the clinical application of MSC-EXOs but also opens up innovative research directions in the field of regenerative medicine.

Topography immune-responsive silk films for skin regeneration

Scar formation and chronic refractory wounds pose a significant threat to public health, with abnormal immune regulation as a key characteristic. However, topography, a crucial factor influencing immune responses, has not been adequately considered in the design of wound dressings. In this study, we constructed a hierarchical structure on silk fibroin (SF) films by combining soft lithography and femtosecond laser ablation, without altering the intrinsic properties of SF. The discontinuity in the hierarchical structure induced a transformation in the morphology of macrophage RAW264.7 cells from round to spindle or pancake-like shapes, leading to phenotypic polarization toward M2 or M1. The timely transition from M1 to M2 polarization and the balance between these states promoted fibroblast L929 cells to express mRNA for FN, coll-I, TGF-β1, and α-SMA. The hierarchical structure of SF films facilitates full-thickness wound repair in vivo by regulating inflammation and promoting neovascularization and collagen deposition. Thus, hierarchical topography presents a promising strategy for the design of immunomodulatory wound dressings.

Engineering Strategies of Plant-Derived Exosome-Like Nanovesicles: Current Knowledge and Future Perspectives

Plant-derived exosome-like nanovesicles (PELNs) from edible plants, isolated by ultracentrifugation, size exclusion chromatography or other methods, were proved to contain a variety of biologically active and therapeutically specific components. Recently, investigations in the field of PELN-based biomedicine have been conducted, which positioned those nanovesicles as promising tools for prevention and treatment of several diseases, with their natural origin potentially offering superior biocompatibility and bioavailability. However, the inadequate targeting and limited therapeutic effects constrain the utility and clinical translation of PELNs. Thus, strategies aiming at bridging the gap by engineering natural PELNs have been of great interest. Those approaches include membrane hybridization, physical and chemical surface functionalization and encapsulation of therapeutic payloads. Herein, we provide a comprehensive overview of the biogenesis and composition, isolation and purification methods and characterization of PELNs, as well as their therapeutic functions. Current knowledge on the construction strategies and biomedical application of engineered PELNs were reviewed. Additionally, future directions and perspectives in this field were discussed in order to further enrich and expand the prospects for the application of engineered PELNs.

Exploring the therapeutic potential of different sources of mesenchymal stem cells: a novel approach to combat burn wound infections

The most prevalent and harmful injuries are burns, which are still a major global health problem. Burn injuries can cause issues because they boost the inflammatory and metabolic response, which can cause organ malfunction and systemic failure. On the other hand, a burn wound infection creates an environment that is conducive to the growth of bacteria and might put the patient at risk for sepsis. In addition, scarring is unavoidable, and this results in patients having functional and cosmetic issues. Wound healing is an amazing phenomenon with a complex mechanism that deals with different types of cells and biomolecules. Cell therapy using stem cells is one of the most challenging treatment methods that accelerates the healing of burn wounds. Since 2000, the use of mesenchymal stem cells (MSCs) in regenerative medicine and wound healing has increased. They can be extracted from various tissues, such as bone marrow, fat, the umbilical cord, and the amniotic membrane. According to studies, stem cell therapy for burn wounds increases angiogenesis, has anti-inflammatory properties, slows the progression of fibrosis, and has an excellent ability to differentiate and regenerate damaged tissue. Figuring out the main preclinical and clinical problems that stop people from using MSCs and then suggesting the right ways to improve therapy could help show the benefits of MSCs and move stem cell-based therapy forward. This review's objective was to assess mesenchymal stem cell therapy's contribution to the promotion of burn wound healing.

Exosomes from mesenchymal stem cells: Potential applications in wound healing

Wound healing is a continuous and complex process regulated by multiple factors, which has become an intractable clinical burden. Mesenchymal stem cell-derived exosomes (MSC-exos) possess low immunogenicity, easy preservation, and potent bioactivity, which is a mirror to their parental cells MSC-exos are important tools for regulating the biological behaviors of wound healing-associated cells, including fibroblasts, keratinocytes, immune cells, and endothelial cells. MSC-exos accelerate the wound healing process at cellular and animal levels by modulating inflammatory responses, promoting collagen deposition and vascularization. MSC-exos accelerate wound healing at the cellular and animal levels by modulating inflammatory responses and promoting collagen deposition and vascularization. This review summarizes the roles and mechanisms of MSC-exos originating from various sources in promoting the healing efficacy of general wounds, diabetic wounds, burn wounds, and healing-related scars. It also discusses the limitations and perspectives of MSC-exos in wound healing, in terms of exosome acquisition, mechanistic complexity, and exosome potentiation modalities. A deeper understanding of the properties and functions of MSC-exos is beneficial to advance the therapeutic approaches for achieving optimal wound healing.

Advanced meta-analysis on therapeutic strategies of mesenchymal derived exosome for diabetic chronic wound healing and tissue remodeling

BACKGROUND

Exosome (EXOs) are rapidly being identified as key mediators of cell-to-cell communication. They convey biologically active molecules to target cells, serve important roles in a range of physiological and pathological processes, and have enormous potential as novel therapeutic strategies.

METHODS

Preclinical research published between 2019 and 2023 provided the study's data searched on different medline search engine, and clinicaltrials.gov was searched for clinical data. These papers were chosen because they are relevant to the research of mesenchymal stem cell-derived exosomes (MSC-EXOs). Thematic synthesis and meta-analysis were used to perform the meta-analysis of diabetic wound healing.

RESULTS

For data extraction, a total of 18 preclinical and 4 clinical trials were selected. Preclinical investigations involving EXOs across various animal wound healing models showed promising potential for treatment. Specifically, following EXO treatment, there was a notable correlation with wound closure rates, with a pooled proportion of 46 % (95 % CI: 0.34; 0.59) and τ2 of 0.0593 after 3 ± 2 days, 54 % (95 % CI: 0.43; 0.65) and τ2 of 0.0465 after 7 ± 2 days, and 69 % (95 % CI: 0.62; 0.76) and τ2 of 0.0221 after 14 ± 2 days, with an egger's test p-value of <0.01. Further investigation into heterogeneity was conducted through subgroup analysis based on the source of EXO and the animal model utilized in the study.

CONCLUSIONS

EXOs are proving to be viable platforms for the treatment of a wide range of disorders in clinical trials. MSC-EXOs exhibited significant diabetic wound healing capabilities across diverse outcomes including wound closure, increase angiogenesis, immunomodulatory ability and skin regeneration with its typical structure and functions.

The Effects of Mesenchymal Stem Cells-Derived Exosomes on Metabolic Reprogramming in Scar Formation and Wound Healing

Pathological scarring results from aberrant cutaneous wound healing due to the overactivation of biological behaviors of human skin fibroblasts, characterized by local inordinate inflammation, excessive extracellular matrix and collagen deposition. Yet, its underlying pathogenesis opinions vary, which could be caused by increased local mechanical tension, enhanced and continuous inflammation, gene mutation, as well as cellular metabolic disorder, etc. Metabolic reprogramming is the process by which the metabolic pattern of cells undergoes a systematic adjustment and transformation to adapt to the changes of the external environment and meet the needs of their growth and differentiation. Therefore, the abnormality of metabolic reprogramming in cells within wounds and scars attaches great importance to scar formation. Mesenchymal stem cells-derived exosomes (MSC-Exo) are the extracellular vesicles that play an important role in tissue repair, cancer treatment as well as immune and metabolic regulation. However, there is not a systematic work to detail the relevant studies. Herein, we gave a comprehensive summary of the existing research on three main metabolisms, including glycometabolism, lipid metabolism and amino acid metabolism, and MSC-Exo regulating metabolic reprogramming in wound healing and scar formation for further research reference.

Applications of mesenchymal stem cell-exosome components in wound infection healing: new insights

The healing process at a wound is made up of many types of cells, growth factors, the extracellular matrix, nerves and blood vessels all interacting with each other in complex and changing ways. Microbial colonization and proliferation are possible at the place of injury, which makes infection more likely. Because of this, any cut has a chance of getting an infection. Researchers have found that wound infections make patients more upset and cost the healthcare system a lot of money. Surgical site infections happen a lot to people who have recently had surgery. This study shows that such surgical infection is linked to a high rate of illness and death. This is shown by the fact that 25% of patients get serious sepsis and need to be transferred to an intensive care unit. In both animal models and people, mesenchymal stem cells (MSCs) play an active role in all stages of wound healing and have positive effects. Exosomes are one of the main things MSCs release. They have effects that are similar to those of the parent MSCs. Various effector proteins, messenger RNA and microRNAs can be transported by extracellular vesicles to control the activity of target cells. This has a big impact on the healing process. These results suggest that using MSC-exosomes as a new type of cell-free therapy could be a better and safer option than whole cell therapy. This review is mostly about how to use parts of MSC-exosomes to help wound infections heal.

Activation of the Wnt/β-catenin signalling pathway enhances exosome production by hucMSCs and improves their capability to promote diabetic wound healing

BACKGROUND

The use of stem cell-derived exosomes (Exos) as therapeutic vehicles is receiving increasing attention. Exosome administration has several advantages over cell transplantation, thus making exosomes promising candidates for large-scale clinical implementation and commercialization. However, exosome extraction and purification efficiencies are relatively low, and therapeutic heterogeneity is high due to differences in culture conditions and cell viability. Therefore, in this study, we investigated a priming procedure to enhance the production and therapeutic effects of exosomes from human umbilical cord mesenchymal stem cells (hucMSCs). After preconditioning hucMSCs with agonists/inhibitors that target the Wnt/β-catenin pathway, we assessed both the production of exosomes and the therapeutic efficacy of the optimized exosomes in the context of diabetic wound healing, hoping to provide a safer, more stable and more effective option for clinical application.

RESULTS

The Wnt signalling pathway agonist CHIR99021 increased exosome production by 1.5-fold without causing obvious changes in the characteristics of the hucMSCs or the size of the exosome particles. Further studies showed that CHIR99021 promoted the production of exosomes by facilitating exocytosis. This process was partly mediated by SNAP25. To further explore whether CHIR99021 changed the cargo that was loaded into the exosomes and its therapeutic effects, we performed proteomic and transcriptomic analyses of exosomes from primed and control hucMSCs. The results showed that CHIR99021 significantly upregulated the expression of proteins that are associated with cell migration and wound healing. Animal experiments confirmed that, compared to control hucMSC-derived exosomes, CHIR99021-pretreated hucMSC-derived exosomes (CHIR-Exos) significantly accelerated wound healing in diabetic mice, enhanced local collagen deposition, promoted angiogenesis, and reduced chronic inflammation. Subsequent in vitro experiments confirmed that the CHIR-Exos promoted wound healing by facilitating cell migration, inhibiting oxidative stress-induced apoptosis, and preventing cell cycle arrest.

CONCLUSIONS

The Wnt agonist CHIR99021 significantly increased exosome secretion by hucMSCs, which was partly mediated by SNAP25. Notably, CHIR99021 treatment also significantly increased the exosomal levels of proteins that are associated with wound healing and cell migration, resulting in enhanced acceleration of wound healing. All of these results suggested that pretreatment of hucMSCs with CHIR99021 not only promoted exosome production but also improved the exosome therapeutic efficacy, thus providing a promising option for large-scale clinical implementation and commercialization.

Impaired receptivity of thin endometrium: therapeutic potential of mesenchymal stem cells

The endometrium is a resilient and highly dynamic tissue, undergoing cyclic renewal in preparation for embryo implantation. Cyclic endometrial regeneration depends on the intact function of several cell types, including parenchymal, endothelial, and immune cells, as well as adult stem cells that can arise from endometrial or extrauterine sources. The ability of the endometrium to undergo rapid, repeated regeneration without scarring is unique to this tissue. However, if this tissue renewal process is disrupted or dysfunctional, women may present clinically with infertility due to endometrial scarring or persistent atrophic/thin endometrium. Such disorders are rate-limiting in the treatment of female infertility and in the success of in vitro fertilization because of a dearth of treatment options specifically targeting the endometrium. A growing number of studies have explored the potential of adult stem cells, including mesenchymal stem cells (MSCs), to treat women with disorders of endometrial regeneration. MSCs are multipotent adult stem cells with capacity to differentiate into cells such as adipocytes, chondrocytes, and osteoblasts. In addition to their differentiation capacity, MSCs migrate toward injured sites where they secrete bioactive factors (e.g. cytokines, chemokines, growth factors, proteins and extracellular vesicles) to aid in tissue repair. These factors modulate biological processes critical for tissue regeneration, such as angiogenesis, cell migration and immunomodulation. The MSC secretome has therefore attracted significant attention for its therapeutic potential. In the uterus, studies utilizing rodent models and limited human trials have shown a potential benefit of MSCs and the MSC secretome in treatment of endometrial infertility. This review will explore the potential of MSCs to treat women with impaired endometrial receptivity due to a thin endometrium or endometrial scarring. We will provide context supporting leveraging MSCs for this purpose by including a review of mechanisms by which the MSC secretome promotes regeneration and repair of nonreproductive tissues.

[Research advances on stem cell-based treatments in animal studies and clinical trials of lymphedema]

Objective

To summarize the progress of the roles and mechanisms of various types of stem cell-based treatments and their combination therapies in both animal studies and clinical trials of lymphedema.

Methods

The literature on stem cell-based treatments for lymphedema in recent years at home and abroad was extensively reviewed, and the animal studies and clinical trials on different types of stem cells for lymphedema were summarized.

Results

Various types of stem cells have shown certain effects in animal studies and clinical trials on the treatment of lymphedema, mainly through local differentiation into lymphoid endothelial cells and paracrine cytokines with different functions. Current research focuses on two cell types, adipose derived stem cells and bone marrow mesenchymal stem cells, both of which have their own advantages and disadvantages, mainly reflected in the therapeutic effect of stem cells, the difficulty of obtaining stem cells and the content in vivo. In addition, stem cells can also play a synergistic role in combination with other treatments, such as conservative treatment, surgical intervention, cytokines, biological scaffolds, and so on. However, it is still limited to the basic research stage, and only a small number of studies have completed clinical trials.

Conclusion

Stem cells have great transformation potential in the treatment of lymphedema, but there is no unified standard in the selection of cell types, the amount of transplanted cells, and the timing of transplantation.

Nanomaterials Modulating the Fate of Dental-Derived Mesenchymal Stem Cells Involved in Oral Tissue Reconstruction: A Systematic Review

The critical challenges in repairing oral soft and hard tissue defects are infection control and the recovery of functions. Compared to conventional tissue regeneration methods, nano-bioactive materials have become the optimal materials with excellent physicochemical properties and biocompatibility. Dental-derived mesenchymal stem cells (DMSCs) are a particular type of mesenchymal stromal cells (MSCs) with great potential in tissue regeneration and differentiation. This paper presents a review of the application of various nano-bioactive materials for the induction of differentiation of DMSCs in oral and maxillofacial restorations in recent years, outlining the characteristics of DMSCs, detailing the biological regulatory effects of various nano-materials on stem cells and summarizing the material-induced differentiation of DMSCs into multiple types of tissue-induced regeneration strategies. Nanomaterials are different and complementary to each other. These studies are helpful for the development of new nanoscientific research technology and the clinical transformation of tissue reconstruction technology and provide a theoretical basis for the application of nanomaterial-modified dental implants. We extensively searched for papers related to tissue engineering bioactive constructs based on MSCs and nanomaterials in the databases of PubMed, Medline, and Google Scholar, using keywords such as "mesenchymal stem cells", "nanotechnology", "biomaterials", "dentistry" and "tissue regeneration". From 2013 to 2023, we selected approximately 150 articles that align with our philosophy.