Exosome from adipose-derived mesenchymal stem cells attenuates scar formation through microRNA-181a/SIRT1 axis

Extracellular vesicles and bioactive peptides for regenerative medicine in cosmetology

As life quality improves and the life pressure increases, people's awareness of maintaining healthy skin and hair grows. However, the use of bioactive peptides in regenerative medical aesthetics is often constrained by the high molecular weight, which impedes skin penetration. In contrast, extracellular vesicles not only possess regenerative properties but also serve as effective carriers for bioactive peptides. Given their anti-inflammatory and bactericidal properties, capacity to promote angiogenesis, optimize collagen alignment, facilitate re-epithelialization and stimulate hair growth, extracellular vesicles become an emerging and promising solution for skin regeneration treatments. The combination of peptides and extracellular vesicles enhances therapeutic efficacy and improves the bioavailability of bioactive peptides. In this review, we summarize the functions of bioactive peptides and plant- and animal-derived extracellular vesicles in regenerative medicine with cosmetology, along with examples of their combined applications. Additionally, we provide an overview of peptides and extracellular vesicles currently available on the market and in clinical practice, discussing the challenges and solutions associated with their use.

The role of macrophages in hypertrophic scarring: molecular to therapeutic insights

Hypertrophic Scar (HS) is a common fibrotic disease of the skin, usually caused by injury to the deep dermis due to trauma, burns, or surgical injury. The main feature of HS is the thickening and hardening of the skin, often accompanied by itching and pain, which seriously affects the patient's quality of life. Macrophages are involved in all stages of HS genesis through phenotypic changes. M1-type macrophages primarily function in the early inflammatory phase by secreting pro-inflammatory factors, while M2-type macrophages actively contribute to tissue repair and fibrosis. Despite advances in understanding HS pathogenesis, the precise mechanisms linking macrophage phenotypic changes to fibrosis remain incompletely elucidated. This review addresses these gaps by discussing the pathological mechanisms of HS formation, the phenotypic changes of macrophages at different stages of HS formation, and the pathways through which macrophages influence HS progression. Furthermore, emerging technologies for HS treatment and novel therapeutic strategies targeting macrophages are highlighted, offering potential avenues for improved prevention and treatment of HS.

Mesenchymal stem cells-derived small extracellular vesicles and apoptotic extracellular vesicles for wound healing and skin regeneration: a systematic review and meta-analysis of preclinical studies

BACKGROUND

Studies examining the therapeutic potential of Mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) in wound healing and skin regeneration have progressed rapidly. Prior to considering clinical translation, a systematic and comprehensive understanding of these experimental details and the overall impact of MSC-EVs on skin regeneration is necessary.

METHODS

83 studies were identified in Web of Science, Embase, and PubMed that satisfied a set of prespecified inclusion criteria. A random effects meta-analysis was conducted for wound closure rate, scar width, blood vessel density and collagen deposition.

CONCLUSIONS

Our findings demonstrate clear potential of MSC-EVs to be developed as therapy for wound healing and skin regeneration both in diabetic and non-diabetic animal models. Moreover, subgroup analyses demonstrated that apoptotic small extracellular vesicles (ApoSEVs) showed better efficacy than apoptotic bodies (ApoBDs) and small extracellular vesicles (sEVs) in wound closure outcome and collagen deposition, while sEVs displayed better than ApoEVs in revascularization. Among frequently used routes of administration, subcutaneous injection displayed a greater improvement to wound closure, collagen deposition and revascularization as compared to dressing/covering. Among easier-access source of MSCs, ADSCs demonstrated the best effect in wound closure rate and collagen deposition, as compared, BMMSCs displayed better in revascularization. Additionally, high heterogeneity observed in collection conditions, separation methods, storage methods, modifications, treatment dose, administration route, and frequency of MSC-EVs underscores the urgent need for standardization in these areas, prior to clinical translation.

PROTOCOL REGISTRATION

PROSPERO CRD42024499172.

New challenges in scar therapy: the novel scar therapy strategies based on nanotechnology

The pathological mechanism of pathological scar is highly complex, encompassing the abnormalities of diverse cytokines, signaling pathways and regulatory factors. To discover more preferable scar treatment options, a variety of distinct approaches have been utilized clinically. Nevertheless, these treatments possess certain side effects and are inclined to relapse. Presently, pathological scar treatment remains a clinical conundrum, and there is an urgent demand for treatment methods that are safe, less traumatic and have lower recurrence rates. New drug delivery systems, novel therapeutic drugs and therapy strategies can enable drugs to permeate the skin effectively, decrease side effects, enhance drug efficacy and even achieve pain-free self-administration. Currently, novel nanotechnologies such as nanomicroneedles, photodynamics mediated by novel photosensitizers, bioelectrical stimulation and 3D printed dressings have been developed for the effective treatment of pathological scars. Additionally, innovative nanoscale fillers, including nano-fat and engineered exosomes, can serve as novel therapeutic agents for the efficient treatment of pathological scars. The intervention of nanomaterials can enhance drug absorption, stabilize and safeguard the active ingredients of drugs, delay or control drug release and enhance bioavailability. This article reviews these new treatment strategies for scar to explore novel approaches for efficient and safe for keloid treatment.

Recent Progress in Mesenchymal Stem Cell-Derived Exosomes for Skin Wound Repair

BACKGROUND

Exosomes are nanometer-sized, lipid bilayer membrane vesicles that are secreted by various cell types. Mesenchymal stem cells (MSCs) have been shown to exert therapeutic effects through the secretion of exosomes via a paracrine pathway. Functions: Recent studies have demonstrated that MSC-derived exosomes (MSC-Exos) can effectively transport various bioactive substances, including proteins, mRNAs, microRNAs, long non-coding RNAs, circular RNAs, and lipids, into target cells. This process regulates multiple aspects during wound repair, such as the inflammatory response, cell proliferation, migration, differentiation, angiogenesis, and matrix remodeling.

POTENTIAL APPLICATIONS

By promoting wound healing and inhibiting scar formation, MSC-Exos have shown great promise for clinical applications in wound repair. This review highlights the recent advances in our understanding of the role and mechanism of MSC-Exos during wound repair, providing insights into their potential use in future therapeutic strategies.

Applications of Exosomal miRNAs from Mesenchymal Stem Cells as Skin Boosters

The skin is the outer layer of the human body, and it is crucial in defending against injuries and damage. The regenerative capacity of aging and damaged skin caused by exposure to external stimuli is significantly impaired. Currently, the rise in average life expectancy and the modern population's aesthetic standards have sparked a desire for stem-cell-based therapies that can address skin health conditions. In recent years, mesenchymal stem cells (MSCs) as therapeutic agents have provided a promising and effective alternative for managing skin regeneration and rejuvenation, attributing to their healing capacities that can be applied to damaged and aged skin. However, it has been established that the therapeutic effects of MSC may be primarily mediated by paracrine mechanisms, particularly the release of exosomes (Exos). Exosomes are nanoscale extracellular vesicles (EVs) that have lipid bilayer and membrane structures and can be naturally released by different types of cells. They influence the physiological and pathological processes of recipient cells by transferring a variety of bioactive molecules, including lipids, proteins, and nucleic acids such as messenger RNAs (mRNAs) and microRNAs (miRNAs) between cells, thus playing an important role in intercellular communication and activating signaling pathways in target cells. Among them, miRNAs, a type of endogenous regulatory non-coding RNA, are often incorporated into exosomes as important signaling molecules regulating protein biosynthesis. Emerging evidence suggests that exosomal miRNAs from MSC play a key role in skin regeneration and rejuvenation by targeting multiple genes and regulating various biological processes, such as participating in inflammatory responses, cell migration, proliferation, and apoptosis. In this review, we summarize the recent studies and observations on how MSC-derived exosomal miRNAs contribute to the regeneration and rejuvenation of skin tissue, with particular attention to the applications of bioengineering methods for manipulating the miRNA content of exosome cargo to improve their therapeutic potential. This review can provide new clues for the diagnosis and treatment of skin damage and aging, as well as assist investigators in exploring innovative therapeutic strategies for treating a multitude of skin problems with the aim of delaying skin aging, promoting skin regeneration, and maintaining healthy skin.

Non-coding RNAs in hypertrophic scars and keloids: Current research and clinical relevance: A review

Hypertrophic scars (HS) and keloids (KD) are lesions that develop as a result of excessive fibroblast proliferation and collagen deposition in response to dermal injury, leading to dysregulation of the inflammatory, proliferative, and remodeling phases during wound healing. HS and KD affect up to 90 % of the population and are associated with lower quality of life, physical health, and mental status in patients. Efficient targeted treatment represents a significant challenge, primarily due to our limited understanding of their underlying pathogenesis. Non-coding RNAs (ncRNAs), which constitute a significant portion of the human transcriptome with minimal or no protein-coding capacity, have been implicated in various cellular physiologies and pathologies and may serve as diagnostic indicators or therapeutic targets. NcRNAs have been found to be aberrantly expressed and regulated in HS and KD. This review provides a summary of the expression profiles and molecular mechanisms of three common ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in HS and KD. It also discusses their potential as biomarkers for the diagnosis and treatment of these diseases and provides novel insights into epigenetic-based diagnosis and treatment strategies for HS and KD.