Accelerates Skin Wound Healing Research Articles

Sea food by-products valorization for biomedical applications: evaluation of their wound regeneration capabilities in an Ex vivo skin model

IntroductionThe skin is often exposed to harmful stimuli that might compromise its integrity and functionality. After an injury, the skin has a limited capability to restore its complex structure, and in the case of severe skin damage, surgical operations and rapid application of wound dressings are often required to promote optimal wound healing. Nowadays, collagen-based biomaterials are widely used in combination with bioactive molecules able to prevent excessive inflammation and possible infections. In line with a circular economy and blue biotechnology approach, it was recently demonstrated that both collagen and bioactive molecules (i.e., antioxidant compounds) can be sustainably obtained from sea food by-products and effectively used for biomaterial development. Herein, we describe and compare the application of two marine collagen-based wound dressings (CBWDs), produced with materials obtained from sea urchin food waste, for the treatment of skin lesions in a wound healing organ culture (WHOC) model.MethodsThe ex vivo WHOC model was set up starting from rat skin explants and the induced lesions were assigned into three different groups: control (CTRL) group, not treated, marine collagen wound dressing (MCWD) group, and antioxidants-enriched marine collagen wound dressing (A-MCWD) group. After 5 and 10 days, specimens were examined for organ maintenance and assessed for the healing process.ResultsImmunohistochemical results showed that both CBWDs were similarly successful in prolonging skin repair, preserving the epidermal barrier up to 5 days under static culture conditions. Histological and gene expression analysis highlighted that the A-MCWD might support and accelerate skin wound healing by exerting antioxidant activity and counteracting inflammation.DiscussionOverall, these findings underline the potential of sea urchin food waste as a novel resource for the development of functional medical devices for the treatment of skin wounds.

FoxO3a Plays a Role in Wound Healing by Regulating Fibroblast Mitochondrial Dynamics.

The skin plays a protective role against harmful environmental stress such as ultraviolet rays. Therefore, the skin is constantly exposed to potential injuries, and wound healing is a vital process for the survival of all higher organisms. Wound healing is dependent on aging and metabolic status at a whole-body level. Because the forkhead box O (FOXO) family plays a role in aging and metabolism, we investigated the molecular functions of FOXO3a in skin wound healing using FoxO3a-/- mice. We observed that FoxO3a-/- mice showed accelerated skin wound healing. During wound healing, more fibroblasts accumulated at the wound edges and migrated into the wound bed in FoxO3a-/- mice. Moreover, cell migration of dermal fibroblasts isolated from FoxO3a-/- mice was significantly induced. During the in vitro cell migration, we observed accelerated mitochondrial fragmentation and decreased oxygen consumption in the mitochondria of FoxO3a-/- fibroblasts. These changes were caused by the upregulation of mitochondrial Rho GTPase 1 (Miro1), which is an essential mediator of microtubule-based mitochondrial motility. Miro1 inhibition significantly attenuated cell migration, mitochondrial fragmentation, and mitochondrial recruitment to the leading edge of the cells. These data indicate that FoxO3a plays a crucial role in wound healing by regulating mitochondrial dynamics.

Autologous platelet-rich fibrin enhances skin wound healing in a feline trauma model

Trauma is a common cause of cutaneous surgical disease with an increased risk of secondary infection in cat clinics. Platelet-rich fibrin (PRF), a platelet and leukocyte concentrate containing multiple cytokines and growth factors, is known to accelerate the healing of wounds. However, how PRF affects wound healing in the cat trauma model has not been fully investigated. The study aimed to examine the impact of PRF on skin wound healing in the cat trauma model. In this study, PRF from cats was successfully produced for our investigation. The models of feline trauma were effectively established. A total of 18 cats were randomly divided into 3 groups (n = 6): (1) Control group (CON); (2) PRF group; (3) Manuka honey group (MAN, as a positive control). Experiments were performed separately on days 7, 14, 21, and 28. Our results showed that PRF was a safe and efficient method of wound healing that did not influence the cat’s body temperature, respiration rate, and heart rate (HR). PRF accelerated skin wound healing in the cat trauma model based on the rate and histological observation of wound healing. In addition, PRF promoted the production of growth factors and suppressed inflammation during wound healing. PRF accelerated wound healing by increasing the formation of collagen fibers, as shown by Masson-trichrome staining. The outcomes of the PRF and MAN groups were comparable. In conclusion, PRF improves the healing of skin wounds in cats by boosting the synthesis of growth factors, reducing inflammation, and enhancing the synthesis of collagen fibers.Graphical

A Dry Patch with In Situ Solid-to-Gel Transformation for All-in-One Skin Wound Care.

Hydrogel-based dressing materials offer significant potential in expediting skin wound healing. Nevertheless, they face several challenges: poor adhesion to wound tissues, difficulties in preservation under ambient conditions, and limited multifunctionality to support all wound healing stages. In this work, a dry patch is designed to address these persistent issues by featuring an in situ solid-to-gel transformation and Janus wet tissue adhesiveness. The HGP patch integrates a wet adhesive layer combining dopamine-conjugated hyaluronic acid (HD) and poly(acrylic acid) (PAA), a drug-loading layer comprising gelatin (Gel), and a nonadhesive gelation layer of poly(vinyl alcohol) (PVA) and sodium alginate (SA). This hierarchical structural design confers exceptional wound adhesion, hemostatic capabilities, and antibacterial and antioxidant activities, as well as immune regulatory properties. These attributes collectively support accelerated skin wound healing, particularly in cases complicated by bacterial infections. This research charts an approach to engineer hydrogel-based wound dressings through on-site hydrogel formation, thus advancing the treatment of wounds afflicted with complex infections.

Visible light accelerates skin wound healing and alleviates scar formation in mice by adjusting STAT3 signaling

During the wound healing process, the activation of signal transducer and activator of transcription 3 (STAT3) is considered crucial for the migration and proliferation of epithelial cells, as well as for establishing the inflammatory environment. However, an excessive STAT3 activation aggravates scar formation. Here we show that 450 nm blue light and 630 nm red light can differentially regulate the phosphorylation of STAT3 (p-STAT3) and its downstream cytokines in keratinocytes. Further mechanistic studies reveal that red light promotes wound healing by activating the PI3 kinase p110 beta (PI3Kβ)/STAT3 signaling axis, while blue light inhibits p-STAT3 at the wound site by modulating cytochrome c-P450 (CYT-P450) activity and reactive oxygen species (ROS) generation. In a mouse scar model, skin wound healing can be significantly accelerated with red light followed by blue light to reduce scar formation. In summary, our study presents a potential strategy for regulating epithelial cell p-STAT3 through visible light to address skin scarring issues and elucidates the underlying mechanisms.

Efficacy and mechanism of Schisandra chinensis active component Gomisin A on diabetic skin wound healing: network pharmacology and in vivo experimental validation

Ethnopharmacological relevanceSchisandra chinensis (Turcz.) Baill., a common traditional Chinese herbal medicine, has been used for the treatment of diabetes mellitus and its complications. However, the major active component for treating diabetic foot ulcers, a serious complication of diabetes mellitus, was unclear. This study aimed to predict the treatment effect of the active components in Schisandra chinensis against diabetic skin wound using network pharmacology and to confirm the underlying mechanism using a diabetic skin wound model in vivo. Aim of the studyTo study the effects and underlying mechanisms of Schisandra chinensis and its main component Gomisin A on diabetic skin wound healing by network pharmacology and high-fat diet (HFD)-induced obese mice model in vivo. Materials and methodsTo determine the effectiveness of Schisandra chinensis on diabetic skin wound, network pharmacology was first used. Components of Schisandra chinensis were obtained from the Traditional Chinese Medicine Systems Pharmacology database. The active components were further verified through absorption, distribution, metabolism and excretion. The potential targets of the active components were identified from the Traditional Chinese Medicine Systems Pharmacology, SwissTargetPrediction, TargetNet, and the Comparative Toxicogenomics Database. Targets related to diabetic skin wound were collected from the GeneCards, OMIM, DisGeNET, and PharmGKB databases. The interaction network formed by the intersection of the two datasets was analyzed using Gephi. Network-based proximity was used to predict the network distance between the active components of Schisandra chinensis and diabetic skin wound. Gomisin A was found to have the lowest Z-score and was administered either orally or via topical injection to HFD-induced obese mice daily until the wounds healed, and its effects on skin wound healing were evaluated. ResultsOnly five active ingredients of Schisandra chinensis were screened in our system: Gomisin A, Longikaurin A, Deoxyharringtonine, Wuweizisu C, and Interiotherin B, which can regulate biological processes related to diabetic skin wound, including positive regulation of phosphorous metabolic process, positive regulation of cell migration, and response to wounding. Network proximity analysis found that Gomisin A has the closest distance-based Z-score among the diabetic skin wound modules and drug targets in the human protein-protein interaction network. The HFD-induced obese mice model further revealed that Gomisin A accelerated skin wound healing by increasing insulin sensitivity and decreasing the advanced glycation end-products mediated toll-like receptor 4 (TLR4)-p38 MAPK-IL6 inflammation signaling pathway. ConclusionsThe network pharmacology and in vivo studies indicated that Gomisin A from Schisandra chinensis played a crucial role in improving diabetic skin wound healing.

NORAD accelerates skin wound healing through extracellular vesicle transfer from hypoxic adipose derived stem cells: miR-524-5p pathway and Pumilio protein mechanism

Skin wound healing is a multifaceted biological process that encompasses a variety of cell types and intricate signaling pathways. Recent research has uncovered that exosomes derived from adipose stem cells, commonly referred to as ADSC exosomes, play a crucial role in facilitating the healing process. Moreover, it has been demonstrated that an anoxic, or low-oxygen, environment significantly enhances the effectiveness of these exosomes in promoting skin repair. The primary objective of this study was to investigate the underlying mechanisms through which ADSC exosomes contribute to Skin wound healing, particularly by regulating the long non-coding RNA known as NORAD under hypoxic conditions. A significant focus of our research was to examine the interplay between the microRNA miR-524-5p and the Pumilio protein, as we aimed to understand how these molecular interactions might influence the overall healing process. In this study, ADSC exosomes were extracted by simulating hypoxia in vitro and their effects on the proliferation and migration of skin fibroblasts (FB) were evaluated. The expression levels of NORAD, miR-524-5p and Pumilio were analyzed by fluorescence quantitative PCR. Pumilio protein was silenced by siRNA technique to evaluate its role in ADSC exosome-mediated wound healing. The experimental results showed that under hypoxia conditions, NORAD levels in ADSC exosomes increased significantly and could effectively regulate the expression of miR-524-5p. After Pumilio protein silencing, the proliferation and migration ability of fibroblasts were significantly reduced, indicating that Pumilio protein played a role in the process of wound healing. By inhibiting miR-524-5p, the expression of Pumilio protein was restored, further confirming its regulatory mechanism.

Transdermal characteristic study of bovine sialoglycoproteins with anti-skin aging and accelerating skin wound healing.

Sialoglycoproteins play important roles in various biological processes, including cell adhesion, immune response, and cell signaling. Our previous studies indicated that the bovine sialoglycoproteins could be developed as a reagent against skin aging and as a new candidate for accelerating skin wound healing as well as inhibiting scar formation. However, transdermal characteristic of the bovine sialoglycoproteins is still unknown. This study investigated the transdermal permeation of the bovine sialoglycoproteins through porcine skin using the Franz diffusion cell method. Our study showed that the bovine sialoglycoproteins could penetrate through the porcine skin with a linear permeation pattern described by the regression equation N% = 11.49 t-3.858, with a high coefficient of determination (R2 = 0.9903). The histochemical results demonstrated the widespread distribution of the bovine sialoglycoproteins between the epidermal and dermal layers, which suggesting parts of the bovine sialoglycoproteins had ability to traverse the epidermal barrier. The results of the lectin microarrays indicated highly enriched glycopatterns on the bovine sialoglycoproteins, which also appeared in permeated porcine skin. The LC-MS/MS analysis further showed that the bovine sialoglycoproteins were composed of approximately 100 proteins with molecular weight ranging from 748.4 kDa to 10 kDa, and there were 23 specific bovine sialoglycoproteins with molecular weight ranging from 69.2 kDa to 10 kDa to be characterized in permeated porcine skin. Parts of the bovine sialoglycoproteins with molecular weight less than 69.2 kDa had ability to traverse the epidermal barrier. Understanding the permeation characteristics of the bovine sialoglycoproteins for developing innovative formulations with therapeutic benefits, contributing to advancements in cosmetic and dermatological fields.

Advances and Challenges in Immune-Modulatory Biomaterials for Wound Healing Applications.

Wound healing progresses through three distinct stages: inflammation, proliferation, and remodeling. Immune regulation is a central component throughout, crucial for orchestrating inflammatory responses, facilitating tissue repair, and restraining scar tissue formation. Elements such as mitochondria, reactive oxygen species (ROS), macrophages, autophagy, ferroptosis, and cytokines collaboratively shape immune regulation in this healing process. Skin wound dressings, recognized for their ability to augment biomaterials' immunomodulatory characteristics via antimicrobial, antioxidative, pro- or anti-inflammatory, and tissue-regenerative capacities, have garnered heightened attention. Notwithstanding, a lack of comprehensive research addressing how these dressings attain immunomodulatory properties and the mechanisms thereof persists. Hence, this paper pioneers a systematic review of biomaterials, emphasizing immune regulation and their underlying immunological mechanisms. It begins by highlighting the importance of immune regulation in wound healing and the peculiarities and obstacles faced in skin injury recovery. This segment explores the impact of wound metabolism, infections, systemic illnesses, and local immobilization on the immune response during healing. Subsequently, the review examines a spectrum of biomaterials utilized in skin wound therapy, including hydrogels, aerogels, electrospun nanofiber membranes, collagen scaffolds, microneedles, sponges, and 3D-printed constructs. It elaborates on the immunomodulatory approaches employed by these materials, focusing on mitochondrial and ROS modulation, autophagic processes, ferroptosis, macrophage modulation, and the influence of cytokines on wound healing. Acknowledging the challenge of antibiotic resistance, the paper also summarizes promising plant-based alternatives for biomaterial integration, including curcumin. In its concluding sections, the review charts recent advancements and prospects in biomaterials that accelerate skin wound healing via immune modulation. This includes exploring mitochondrial transplantation materials, biomaterial morphology optimization, metal ion incorporation, electrostimulation-enabled immune response control, and the benefits of composite materials in immune-regulatory wound dressings. The ultimate objective is to establish a theoretical foundation and guide future investigations in the realm of skin wound healing and related materials science disciplines.

Extracellular vesicles derived from "serum and glucose" deprived HUCMSCs promoted skin wound healing through enhanced angiogenesis.

Extracellular vesicles (EVs) produced from MSCs were currently considered as a novel therapeutic agent for skin tissue regeneration and repair. Preconditioning stem cells may activate more molecular pathways and release more bioactive agents. In this study, we obtained EVs from normal (N-EVs) and serum- and glucose-deprived (SGD-EVs) human umbilical cord mesenchymal stem cells (HUCMSCs), and showed that SGD-EVs promoted the migration, proliferation, and tube formation of HUVECs in vitro. In vivo experiments utilizing a rat model show that both N-EVs and SGD-EVs boosted angiogenesis of skin defects and accelerated skin wound healing, while treating wounds with SGD-EVs led to faster skin healing and enhanced angiogenesis. miRNA sequencing showed that miR-29a-3p was abundant in SGD-EVs, and overexpressing miR-29a-3p enhanced the angiogenic ability of HUVECs, while inhibiting miR-29a-3p presented the opposite effect. Further studies demonstrated that miR-29a-3p directly targeted CTNNBIP1, which mediated angiogenesis of HUCMSCs-derived EVs through inhibiting CTNNBIP1 to activate Wnt/β-catenin signaling pathway. Taken together, these findings suggested that SGD-EVs promote angiogenesis via transferring miR-29a-3p, and activation of Wnt/β-catenin signaling pathway played a crucial role in SGD-EVs-induced VEGFA production during wound angiogenesis. Our results offered a new avenue for modifying EVs to enhance tissue angiogenesis and augment its role in skin repair.

Multifunctional sprayable carboxymethyl chitosan/polyphenol hydrogel for wound healing

The use of facile methods to synthesize environmentally friendly and multifunctional hydrogel dressings is still a major challenge in development. Herein, Turkish gall extract (TGE) and carboxymethyl chitosan (CMCS) were combined and sprayed using a dual syringe to form a multifunctional TGE-CMCS hydrogel (TC gel) in one step through abundant hydrogen bonding between functional groups as a green approach. TC gel showed rapid gelation at 19.0 ± 2.9 s. Apart from the advantage of being able to adapt to different wound shapes, TC gel retained the antioxidant, antibacterial, hemostatic and anti-inflammatory properties of TGE. In vitro antibacterial experiments showed that TC-gel eliminated 98.27 ± 0.79 % of Staphylococcus aureus and 98.87 ± 1.08 % of Escherichia coli. Compared with TGE or CMCS alone, TC gel accelerates skin wound healing due to its three-dimensional network structure and continuous release of active components at the wound site, enhancing re-epithelialization, improving collagen deposition, and increasing angiogenesis. The wound healing rate of full-thickness skin defect rats treated with TC gel was 93.98 ± 0.63 % on the 10th day. These results suggest that TC gel combined with a facile and scalable manufacturing method is a promising multifunctional wound dressing for clinical wound management.

A Bioswitchable MiRNA Delivery System: Tetrahedral Framework DNA-Based miRNA Delivery System for Applications in Wound Healing.

The human body's primary line of defense, the skin, is especially prone to harm. Although microRNA (miRNA)-based therapies have attracted increasing attention for skin wound healing, their applications remain limited owing to a range of issues. Tetrahedral framework DNA (tFNA), a nanomaterial possessing nucleic acid characteristics, exhibits an excellent biocompatibility, in addition to anti-inflammatory and transdermal delivery capabilities, and can accelerate skin wound healing. Due to its potential to exert synergistic action with therapeutic miRNA, tFNA has been considered an ideal vehicle for miRNA therapy. The design and synthesis of a bioswitchable miRNA delivery system (BiRDS) is reported, which contains three miRNAs as well as a nucleic acid core to maximize the loading capacity while preserving the characteristics of tFNA. A high stability, excellent permeability of cells as well as tissues and good biological compatibility are demonstrated. By selectively inhibiting heparin-binding epidermal growth factor (HB-EGF), the BiRDS can inhibit the NF-κB pathway while simultaneously controlling the PTEN/Akt pathway. As a result, the BiRDS helps wound healing go through the inflammation to the proliferative phase. This study demonstrates the advantages of the BiRDS in miRNA-based therapy and provides new research ideas for the treatment of skin-related diseases.

Rapid and Scar Free Wound Repair by Using a Biologically Flexible and Conductive Dressing Under Electrical Stimulation

AbstractAbnormal healing following skin injury, such as slow healing and scar formation, can significantly affect an individual's life. Complex treatment methods and cumbersome instruments have reduced the efficacy of treating such diseases. In this study, a novel biocompatible liquid metal (LM) composite wound dressing (LGPU) is designed by synthesizing polyurea polyurethane (PU) and blending it with LM modified with glutathione (GSH), a bioactive three‐peptide compound. The effects of external electrical stimulation (ES) on wound‐induced hair follicle neogenesis are explored. The dressings exhibited a few important properties, including conductivity, high stretchability, recyclability, and, most importantly, excellent self‐healing capacity, owing to the liquid nature of the LM fillers and the highly dynamic characteristics of hydrogen bonds. Furthermore, the combination therapy with LGPU and ES promoted fibroblast migration and accelerated wound healing. The wounds treated with the combination therapy fully healed in nine days, while the wounds in the blank group are still in a scabbing state. Remarkably, this treatment method can activate the regeneration and healthy growth of hair follicles at the site of injury, which is beneficial for reducing wound scarring. Collectively, this innovative therapy provides a facile strategy to accelerate skin wound healing and achieve scar‐free repair.

High molecular weight hyaluronic acid-liposome delivery system for efficient transdermal treatment of acute and chronic skin photodamage

Photodamage is one of the most common causes of skin injury. High molecular weight hyaluronic acid (HHA) has shown immense potential in the treatment of skin photodamage by virtue of its anti-inflammatory, reparative, and antioxidative properties. However, due to its large molecular structure of HHA, HHA solution could only form a protective film on the skin surface in conventional application, failing to effectively penetrate the skin, which necessitates the development of new delivery strategies. Liposomes, with a structure similar to biological membranes, have garnered extensive attention as transdermal drug delivery carriers because of their advantages in permeability, dermal compatibility, and biosafety. Herein, we have developed a HHA-liposome transdermal system (HHL) by embedding HHA into the liposome structure using reverse evaporation, high-speed homogenization, and micro-jet techniques. The effective penetration and long-term residence of HHA in skin tissue were multidimensionally verified, and the kinetics of HHA in the skin were extensively studied. Moreover, it was demonstrated that HHL significantly strengthened the activity of human keratinocytes and effectively inhibits photo-induced cellular aging in vitro. Furthermore, a murine model of acute skin injury induced by laser ablation was established, where the transdermal system showed significant anti-inflammatory and immunosuppressive properties, promoting skin proliferation and scar repair, thereby demonstrating immense potential in accelerating skin wound healing. Meanwhile, HHL significantly ameliorated skin barrier dysfunction caused by simulated sunlight exposure, inhibited skin erythema, inflammatory responses, and oxidative stress, and promoted collagen expression in a chronic photodamage skin model. Therefore, this transdermal delivery system with biocompatibility represents a promising new strategy for the non-invasive application of HHA in skin photodamage, revealing the significant potential for clinical translation and broad application prospects. Statement of significanceThe transdermal system utilizing hyaluronic acid-based liposomes enhances skin permeability and retains high molecular weight hyaluronic acid (HHL). In vitro experiments with human keratinocytes demonstrate significant skin repair effects of HHL and its effective inhibition of cellular aging. In an acute photodamage model, HHL exhibits stronger anti-inflammatory and immunosuppressive properties, promoting skin proliferation and scar repair. In a chronic photodamage model, HHL significantly improves skin barrier dysfunction, reduces oxidative stress induced by simulated sunlight, and enhances collagen expression.

PH-Responsive Calcium Ions and Crocetin Releasing Hydrogel for Accelerating Skin Wound Healing.

The ideal and highly anticipated dressing for skin wounds should provide a moist environment, possess antibacterial properties, and ensure sustained drug release. In the present work, a hyaluronic acid-based hydrogel was formed by cross-linking crocetin and CaCO3@polyelectrolyte materials (CaCO3@PEM) microspheres with HA hydrogels via hydrogen bond and amido bonding (CaCO3@PEM@Cro@HA hydrogel, CPC@HA hydrogel). Moreover, the CPC@HA hydrogel had the capability of sustained, controlled release of calcium ions and crocetin via pH-sensitive and accelerated skin wound healing. The experiment results showed that the CPC@HA hydrogel exhibited porous network structures, stable physical properties, and had antibacterial properties and biocompatibility in vitro. In addition, the CPC@HA hydrogel covering on the skin wound could reduce inflammation and promote wound healing. The high expression of angiogenic cytokines (CD31) and epidermal terminal differentiation markers (Loricrin) of wound healing tissue suggested the CPC@HA hydrogel also had the function of promoting the remodeling of regenerated skin. Overall, CPC@HA hydrogel has promising potential for clinical applications in accelerating skin wound repair.

Therapeutic effect of ZnO NPs–polyhexanide-hydrogel on Staphylococcus aureus-induced skin wound infection in mice

Nanometer zinc oxide (ZnONPs) offers strong antibacterial, wound healing, hemostatic benefits, and UV protection. Additionally, poly(hexamethylene biguanide)hydrochloride (PHMB) is an environmentally friendly polymer with strong bactericidal properties. However, the synergistic effect of the combination of ZnONPs and PHMB has not been previously explored. The purpose of this study is to explore the synergies of ZnONPs and PHMB and the healing efficacy of ZnO NPs–PHMB-hydrogel on skin wounds in mice infected with Staphylococcus aureus. Therefore, the mice were subjected to skin trauma to create a wound model and were subsequently infected with S. aureus, and then divided into various experimental groups. The repair effect was evaluated by assessing the healing rate, as well as measuring the levels of TNF-α, IL-2, EGF, and TGF-β1 contents in the tissue. On the 4th and 9th days post-modeling, the Z-P group exhibited notably higher healing rates compared to the control group. However, on the 15th day, both the Z-P and AC groups achieved healing rates exceeding 99%. ZnO NPs–PHMB-hydrogel promoted the formation of a fully restored epithelium, increased new hair follicles and sebaceous glands beneath the epidermis, and markedly reduced inflammatory cell infiltration, which was markedly distinct from the control group. On the 7th day, the Z-P group exhibited significantly higher levels of EGF and TGF-β1, along with a considerable reduction in the TNF-α levels as compared with the control group. These results affirmed that ZnO NPs–PHMB-hydrogel effectively inhibits S. aureus infection and accelerates skin wound healing.

Hydrogen sulfide regulates macrophage polarization and necroptosis to accelerate diabetic skin wound healing

Hydrogen sulfide (H2S), recognized as the third gasotransmitter, plays a pivotal role in the pathophysiological processes of various diseases. Cystathionine γ-lyase (CSE) is the main enzyme for H2S production in the skin. However, effects and mechanisms of H2S in diabetic skin wound healing remain unclear. Our findings revealed a decrease in plasma H2S content in diabetic patients with skin wounds. CSE knockout (KO) diabetic mice resulted in delayed wound healing, reduced blood perfusion, and CD31 expression around the wounds. It also led to increased infiltration of inflammatory cells and M1-type macrophages, decreased collagen levels, α-smooth muscle actin (α-SMA), and proliferating cell nuclear antigen (PCNA) expression. Additionally, there were enhanced expressions of necroptosis related proteins, including receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain like protein (MLKL). In comparison, sodium hydrosulfide (NaHS), H2S donor, accelerated skin wound healing in leptin receptor deficiency (db/db) mice. This acceleration was accompanied by increased blood perfusion and CD31 expression, reduced infiltration of inflammatory cells and M1-type macrophages, elevated collagen levels, α-SMA, and PCNA expressions, and decreased necroptosis-related protein expressions together with nuclear factor-κB (NF-κB) p65 phosphorylation. In conclusion, H2S regulates macrophage polarization and necroptosis, contributing to the acceleration of diabetic skin wound healing. These findings offer a novel strategy for the treatment of diabetic skin wounds.

Functional diversity of apoptotic vesicle subpopulations from bone marrow mesenchymal stem cells in tissue regeneration.

Apoptosis releases numerous apoptotic vesicles that regulate processes such as cell proliferation, immunity, and tissue regeneration and repair. Now, it has also emerged as an attractive candidate for biotherapeutics. However, apoptotic vesicles encompass a diverse range of subtypes, and it remains unclear which specific subtypes play a pivotal role. In this study, we successfully isolated different apoptotic vesicle subtypes based on their sizes and characterized them using NTA and TEM techniques, respectively. We compared the functional variances among the distinct subtypes of apoptotic vesicles in terms of stem cell proliferation, migration, and differentiation, as well as for endothelial cell and macrophage function, effectively identifying subtypes that exhibit discernible functional differences. ApoSEV (with diameter<1000nm) promoted stem cell proliferation, migration, and multi-potent differentiation, and accelerated skin wound healing of diabetes mouse model, while apoBD (with diameter>1000nm) played the opposite effect on cell function and tissue regeneration. Lastly, employing protein analysis and gene sequencing techniques, we elucidated the intrinsic mechanisms underlying these differences between different subtypes of apoEVs. Collectively, this study identified that apoptotic vesicle subtypes possessed distinct bio-functions in regulating stem cell function and behaviour and modulating tissue regeneration, which primarily attribute to the distinct profiling of protein and mRNA in different subtypes. This comprehensive analysis of specific subtypes of apoEVs would provide novel insights for potential therapeutic applications in cell biology and tissue regeneration.

A Thermosensitive Hydrogel with Efficient NIR Photothermal Conversion as Injectable Wound Dressing for Accelerating Skin Wound Healing

AbstractBacterial infection at wound sites can easily induce robust inflammation. M1 macrophages at wound sites can cause cascade inflammatory reactions to mediate a vicious inflammation cycle. Meanwhile, the hypoxia situation further aggravates the destruction and contraction of blood vessels in the wound microenvironment, therefore, hindering the infected wound healing process. Here, a thermosensitive hydrogel is reported to solve the above challenges by eliminating bacteria based on the photothermal effect, regulating the inflammatory immune microenvironment, and providing oxygen (O2). In vitro and in vivo experiments confirmed that the hydrogel has great O2‐producing properties. Based on the excellent photothermal properties of AIEgens, the hydrogel has a good bactericidal effect against S. aureus (100%) and E. coli (98.85%). The RNA‐sequencing revealed that Cur@AIE@MnO2/gel can interfere with the metabolic process and genetic material repair process to impact bacteria proliferation and biofilm dispersal, thus achieving excellent anti‐bacterial efficacy. Moreover, Cur@AIE@MnO2/gel can also up‐regulate anti‐inflammatory genes, down‐regulate pro‐inflammatory genes in macrophages, and facilitate the promotion of macrophage polarization from M1 to M2 to relieve inflammation. The therapeutic experiments show that this hydrogel accelerated the wound‐healing process. Therefore, this work may open new avenues for the development of novel dressings for bacterial‐infected wounds.

Human Parathyroid Hormone (1–34) accelerates skin wound healing through inducing cell migration via up-regulating the expression of Rac1

Delayed wound healing is a public issue that imposes a significant burden on both society and the patients themselves. To date, although numerous methods have been developed to accelerate the speed of wound closure, the therapeutic effects are partially limited due to the complex procedures, high costs, potential side effects, and ethical concerns. While some studies have reported that the in-vivo application of Human Parathyroid Hormone (1–34) (hPTH(1–34)) promotes the wound-healing process, the definitive role and underlying mechanisms through which it regulates the behavior of fibroblasts and keratinocytes remains unclear. Herein, hPTH(1–34)’s role in cell migration is evaluated with a series of in-vitro and in-vivo studies, whereby hPTH(1–34)’s underlying mechanism in activating the two types of cells was detected. The in-vitro study revealed that hPTH(1–34) enhanced the migration of both fibroblasts and HaCaT cells. Ras-associated C3 botulinum toxin subunit 1 (Rac1), a classical member of the Rho family, was upregulated in hPTH(1–34)-treated fibroblasts and HaCaT cells. Further study by silencing the expression of Rac1 with siRNA reversed the hPTH(1–34)-enhanced cell migration, thus confirming that Rac1 was involved in hPTH(1–34)-induced cell behavior. In-vivo study on rat wound models confirmed the effects of hPTH(1–34) on fibroblasts and keratinocytes, with increased collagen deposition, fibroblasts accumulation, and Rac1 expression in the hPTH(1–34)-treated wounds. In summary, the present study demonstrated that hPTH(1–34) accelerated wound healing through enhancing the migration of cells through the up-regulation of Rac1 expression.