Skin Repair Research Articles

Active Components and Skin Care Mechanism of Sea Grape (Caulerpa lentillifera) Extract

This study successfully obtained sea grape extract through mechanical extraction methods, which is rich in active components. These primary active ingredients include high concentrations of crude polysaccharides, total phenolics, and flavonoids. Using two zebrafish models, we observed significant skin moisturizing and repair effects of this extract. Further experiments demonstrated its remarkable anti-aging and skin tightening effects through the DPPH method and elastase inhibition assay. Additionally, the extract showed significant anti-inflammatory effects in a model built on 3 dpf (days post fertilization) Tg (corola: EGFP) transgenic zebrafish. The extract’s safety and reliability were confirmed through a final dermal application test on rabbits. Furthermore, we also analyzed the possible mechanism of Caulerpa lentillifera extract skin care. Overall, our research indicates that sea grapes hold tremendous potential as a novel natural ingredient for skincare. It is foreseeable that sea grapes will become an indispensable component in the future medical skincare market.

Sticky Science: Using Complex Coacervate Adhesives for Biomedical Applications.

Tissue adhesives are used for various medical applications, including wound closure, bleeding control, and bone healing. Currently available options often show weak adhesion or cause adverse effects. Recently, there has been an increasing interest in complex coacervates as medical adhesives. Complex coacervates are formed by mixing oppositely charged macromolecules that associate and undergo liquid-liquid phase separation, in which the dense bottom phase is the complex coacervate. Complex coacervates are strong and often biocompatible, and show strong underwater adhesion. The properties of the resulting materials are tunable by intrinsic factors such as polymer chemistry, molecular weight, charge density, and topology of the macromolecules, as well as extrinsic factors such as temperature, pH, and salt concentration. Therefore, complex coacervates are interesting new candidates for medical adhesives. In this review, it is described how complex coacervates form and how different factors influence their behavior. Next, an overview of recent studies on complex coacervates in the context of medical adhesives is presented. The application of complex coacervates as hemostatic or embolic agents, skin or bone repair adhesives, and soft tissue sealants is discussed. Lastly, additional possibilities for utilizing these materials in the future are discussed.

Epidemiology of complications after non-compulsory planned hardware-removal after limbs fracture

IntroductionRemoval of hardware (HR) following a fracture is a frequent question from patients. The incidence of this kind of intervention remains very variable depending on the healthcare systems and its interest is debated in view of the benefits and associated risks that remain poorly defined. Mandatory preoperative information cannot be given optimally in this context. ObjectiveTo determine the rate of complications (major and minor) after non-compulsory planned hardware-removal following a limb fracture. HypothesisThe rate of major complications was greater than 1%. MethodsA 10-year retrospective single-center study included 1990 patients who had undergone routine HR. Analysis of medical records, with a minimum of one year of follow-up, allowed us to collect: patient data, the type and anatomical location of the osteosynthesis material, as well as the occurrence of a postoperative complication, categorized as a major complication (resulting in either a new surgical procedure, re-hospitalization, or lasting functional impairment) or a minor complication. ResultsOverall, 4.1% (79/1990) of patients experienced postoperative complications, including 1.56% (31/1990) major complications and 21 surgical revisions (1.06%). The time to onset of complications was 9.1 +/- 8.4 days. The most common complications were deep infections and impaired skin healing with superficial infection (55/79, 69.6%). Locations "around the knee" and "around the ankle" were at higher risk of complications (p < 0.01). Smoking was identified as a significant risk factor for complications, particularly deep infection (p = 0.004, OR = 8.7 [1.98; 38.11]). DiscussionNon-mandatory routine RH has a significant complication rate even in a healthy population. Preoperative information of the patient and the assessment of the benefit/risk balance are essential in this indication. This study also raises the question of mandatory smoking cessation preoperatively. Level of evidenceIV; retrospective study.

Spatial dimension cues derived from fibrous scaffolds trigger mechanical activation to potentiate the paracrine and regenerative functions of MSCs via the FAK-PI3K/AKT axis

Secretomes from mesenchymal stem cells (MSCs) have significant therapeutic potential and could be the basis for future MSCs treatments. Innovative design of the topology of biomaterials, which mechanically regulate cell behavior and function, can tremendously improve the efficacy of stem cell therapy. However, how spatial dimension cues derived from specific topology command cell mechanotransduction to regulate the paracrine function of MSCs remains unknown. In this study, the three-dimensional (3D) fibrous constructs with box-like pores and precise strand spacing from 150 µm down to only 40 µm were manufactured using melt electrowriting (MEW), which were used to systematically investigate the spatial dimension cues-triggered mechanotransduction of adipose-derived mesenchymal stem cells (Ad-MSCs) and their impact on the paracrine and regeneration function of Ad-MSCs. The results demonstrated that spatial instructions from the 3D fibrous constructs could influence the spatial reorganization of the cytoskeleton, resulting in cell elongation and augmented immunomodulatory and angiogenic paracrine effects of Ad-MSCs, which was most pronounced at a minimum strand spacing of 40 µm. Besides, mechanical activation of the FAK-PI3K/AKT axis significantly enhanced the paracrine function of Ad-MSCs. In vivo experiments demonstrated that the Ad-MSCs trained using well-defined 3D fibrous constructs with a strand spacing of 40 µm significantly promoted skin regeneration via paracrine signals. In conclusion, this study provides a new horizon for deciphering space dimension insights into the interactional mechanisms of mechanotransduction in regulating cell function, which has inspired innovations in biomaterials for improving tissue regeneration. Statement of significanceThis study emphasized that designing cell-scale spatial dimension cues to command mechanical activation via the FAK-PI3K/AKT axis could significantly enhance the paracrine and regenerative functions of Ad-MSCs. Paracrine signals of Ad-MSCs triggered by mechanical activation promoted skin repair and regeneration via the immunomodulation and angiogenesis. The proposed mechanobiological signal transduction triggered by spatial dimensional cues, which potentiates the paracrine and regenerative functions of Ad-MSCs, is a promising engineering strategy and is expected to provide new inspirations for the development of biomaterials based on biophysical signals for cellular behavior modulation.

Diabetic Microenvironment‐Unlocked BioHJzyme with H2S Evolution for Robust Anti‐Pathogens and Hyperinflammatory Wound Regeneration Through TGF‐β/Smad Pathway

AbstractDeferred diabetic skin healing is an ever‐growing complication owing to the hyperglycemic microenvironment, which accelerates the generation of advanced glycated end products (AGEs) and provides a hotbed for pathogenic infection. Here, the H2S‐evolving bio‐heterojunction enzyme (BioHJzyme), which is consisted by MXene/FeS2 and glucose oxidase (GOx) is devised. It presents glutathione peroxidase (GPx)‐ and peroxidase (POD)‐mimetic antibacterial activity for anti‐pathogens and wound regeneration by AGEs depression. The GOx catalyzes glucose, resulting in reducing the bacterial nutrient and supplying H2O2. The POD‐mimetic activity of the BioHJzyme catalyzes the H2O2 to hydroxyl radical (•OH) with a turnover number of 4.45 × 10−1 s−1, while the GPx‐mimetic activity of it consumes glutathione for further •OH accumulation. The anti‐pathogens can be enhanced by near infrared laser (NIR) irradiation owing to the efficient separation of electron‐hole pairs originated from the heterostructure, which presents NIR‐activatable •OH and 1O2 production. Moreover, the BioHJzyme evolves H2S in acidic environment, acting as an H2S donor, which protects cells around the wound from oxidative damage and AGEs, rescues mitochondrial respiration, improves the extracellular matrix deposition and ameliorates dysfunction of fibroblasts for diabetic skin regeneration through TGF‐β/Smad pathway. The work provides a proof‐of‐concept for bacteria‐invaded diabetic wound regeneration via H2S‐evolving BioHJzyme.

Fabrication of Thymol-loaded Isabgol/Konjac Glucomannan-based Microporous Scaffolds with Enriched Antioxidant and Antibacterial Properties for Skin Tissue Engineering Applications.

An antioxidant, antibacterial, and biocompatible biomaterial is essential to repair skin wounds effectively. Here, we have employed two natural biopolymers, isabgol (ISAB) and konjac glucomannan (KGM), to prepare microporous scaffolds by freezing and lyophilization. The scaffolds are loaded with thymol (THY) to impart potent antioxidant and antibacterial activities. The physicochemical properties of the ISAB+KGM+THY scaffold, like porosity (41.8±2.4 %), swelling, and biodegradation, were optimal for tissue regeneration application. Compared to the control, ISAB+KGM+THY scaffolds promote attachment, migration, and proliferation of L929 fibroblasts. The antioxidant activity of the ISAB+KGM+THY scaffold was significantly improved after loading THY. This would protect the tissues from oxidative damage. The antibacterial activity of the ISAB+KGM+THY scaffold was significantly higher than that of the control, which would help prevent bacterial infection. The vascularization ability of the ISAB+KGM scaffold was not altered by incorporating THY in the ISAB+KGM scaffold. Therefore, a strong antioxidant, antibacterial, and biocompatible nature of the ISAB+KGM+THY scaffold could be useful for various biomedical applications.

Human salivary histatin 1 regulating IP3R1/GRP75/VDAC1 mediated mitochondrial-associated endoplasmic reticulum membranes (MAMs) inhibits cell senescence for diabetic wound repair

RationaleDifficulty in skin wound healing is a concern for diabetic patients across the world. Impaired mitochondrial dysfunction and aging-related vascular dysfunction in human umbilical vein endothelial cells (HUVECs) caused by oxidative stress are major impediments to diabetic wound healing. However, research on skin repair at the mechanistic level by improving mitochondrial function and inhibiting oxidative stress-induced HUVEC senescence remains lacking. Methods and resultsHuman saliva effectively inhibits the natural aging of HUVECs through immunodepletion experiments. Histatin 1 (Hst1), a short peptide comprising 38 amino acids, is the primary component of human saliva that prevents HUVEC aging. Based on in vitro findings, Hst1 decreased staining for senescence-associated β-galactosidase activity and expression of mediators of senescence signaling, including p53, p21, and p16. Mechanistically, HUVEC senescence is associated with Hst1-modulated nuclear factor Nrf2 signaling as Hst1 induces ERK-mediated Nrf2 nuclear translocation through NADPH oxidase-dependent ROS regulation, reinforced Nrf2 antioxidant response, and suppressed oxidative stress. RNA sequencing identified that the mitochondrial-related gene set was enriched in the Hst1 group. Coimmunoprecipitation indicated that Hst1 delayed hydrogen peroxide-induced HUVEC senescence by inhibiting mitochondria-associated endoplasmic reticulum (ER) membrane formation mediated by inositol 1,4,5-trisphosphate receptor 1-glucose-regulated protein 75-voltage-dependent anion channel 1 (VDAC1) complex interactions. Furthermore, in aging HUVECs, Hst1 treatment or VDAC1 silencing with small interfering RNA hindered calcium (Ca2+) transfer from the ER to the mitochondria, thereby ameliorating mitochondrial Ca2+ overload and restoring mitochondrial function. In an in vivo mouse model of diabetes mellitus skin defects, Hst1 facilitated wound healing by stimulating the new blood vessel formation and impeding the expression of senescent biomarkers. ConclusionsThis study proposes a theoretical solution that Hst1 can restore mitochondrial function by inhibiting oxidative stress or cellular senescence, thereby promoting angiogenesis and diabetic wound repair.

Galectin-3/Gelatin Electrospun Scaffolds Modulate Collagen Synthesis in Skin Healing but Do Not Improve Wound Closure Kinetics.

Chronic wounds remain trapped in a pro-inflammatory state, with strategies targeted at inducing re-epithelialization and the proliferative phase of healing desirable. As a member of the lectin family, galectin-3 is implicated in the regulation of macrophage phenotype and epithelial migration. We investigated if local delivery of galectin-3 enhanced skin healing in a full-thickness excisional C57BL/6 mouse model. An electrospun gelatin scaffold loaded with galectin-3 was developed and compared to topical delivery of galectin-3. Electrospun gelatin/galectin-3 scaffolds had an average fiber diameter of 200 nm, with 83% scaffold porosity approximately and an average pore diameter of 1.15 μm. The developed scaffolds supported dermal fibroblast adhesion, matrix deposition, and proliferation in vitro. In vivo treatment of 6 mm full-thickness excisional wounds with gelatin/galectin-3 scaffolds did not influence wound closure, re-epithelialization, or macrophage phenotypes, but increased collagen synthesis. In comparison, topical delivery of galectin-3 [6.7 µg/mL] significantly increased arginase-I cell density at day 7 versus untreated and gelatin/galectin-3 scaffolds (p < 0.05). A preliminary assessment of increasing the concentration of topical galectin-3 demonstrated that at day 7, galectin-3 [12.5 µg/mL] significantly increased both epithelial migration and collagen content in a concentration-dependent manner. In conclusion, local delivery of galectin 3 shows potential efficacy in modulating skin healing in a concentration-dependent manner.

Seroma incidence and risk factors in women undergoing mastectomies as surgical breast cancer treatment.

Seroma is the most common early complication following surgical breast cancer treatment. Its development is associated with pain, scar complications, adjuvant therapy delays, the need for outpatient visits, and increased care costs. Assess seroma incidence and risk factors in women undergoing mastectomies. This study comprises a prospective cohort encompassing women aged 18 or over undergoing mastectomies as a breast cancer treatment. Patients underwent physiotherapy on the 1st, 7th, and 30th postoperative days for kinetic-functional, skin, and wound healing assessments and were attended to by nurses for surgical wound care, draining liquid on the 7th, 14th, and 21st postoperative days. Seroma was defined as the presence of local fluctuations requiring puncture, regardless of the punctured volume. A total of 249 women were evaluated, with a mean age of 57.5 (SD = 11.8). A total of 77.1% were classified as overweight or obese, 60.2% were hypertensive, 21.3% were diabetic, 66.7% underwent neoadjuvant chemotherapy and 62.7% underwent axillary lymphadenectomies. Seroma incidence was 71.1%, requiring, on average, two aspiration punctures until condition resolution. Overweight or obese women and those who underwent axillary lymphadenectomies exhibited 1.92- and 2.06-fold higher risk for seroma development (OR = 1.92; 95% CI 1.02-3.61; p = 0.042; and OR = 2.06; 95% CI 1.17-3.63; p = 0.012), respectively. Seroma incidence was very high. Being overweight or obese and undergoing axillary lymphadenectomy comprise independent seroma development risk factors. This study is part of a randomized clinical trial evaluating the effectiveness of applying compressive taping to prevent post-mastectomy seroma, which was approved by the Brazilian National Cancer Institute, Research Ethics Committee (2,774,824), and it is registered in the ClinicalTrials.gov (NCT04471142, on July 15, 2020).

Biliverdin improved angiogenesis and suppressed apoptosis via PI3K/Akt-mediated Nrf2 antioxidant system to promote ischemic flap survival

Plastic and reconstructive surgeons frequently utilize random skin flap transplantation to repair skin defects. However, the procedure carries a substantial risk of necrosis. Previous research has suggested that Biliverdin (Bv), the main component of Calculus Bovis, possessed potent anti-ischemic properties, making it a potential therapeutic agent for skin flap survival. Hence, in this study, the potential of Bv in promoting flap survival has been comprehensively investigated. Network pharmacology analysis revealed that the pharmacological effects of Bv on ischemic diseases may be attributed to its modulation of various signaling molecules, including the PI3K-Akt pathway. In vitro results demonstrated that Bv treatment significantly promoted angiogenesis in human umbilical vein endothelial cells (HUVEC), even in the presence of H2O2. This was evident by the increased cell proliferation, enhanced migration, and improved tube formation. Bv also effectively attenuated the intracellular generation of reactive oxygen species (ROS) induced by H2O2, which was achieved by suppressing mitochondrial ROS production through the PI3K/Akt-mediated activation of Nrf2/HO-1 signaling pathway. Consequently, Bv treatment led to a significant reduction in apoptosis and an increase in cell viability of HUVEC. Furthermore, in vivo experiment demonstrated that Bv treatment vastly elevated flap survival through enhancing angiogenesis while decreasing oxidative stress and apoptosis, which was comparable to the results of positive control of N-acetylcysteine (Nac). In conclusion, this study not only established a solid foundation for future study on therapeutic potential of Bv, but also proposed a promising treatment approach for enhancing the success rate of flap transplants and other ischemic-related tissue repair.

Novel modalities for hair growth &amp; skin repair

Background/Objectives: Evaluate the efficacy and long-term results of established and novel treatment modalities on skin repair and hair growth. Examine the deleterious effects of inflammation in aging and disease. We present a thorough literature review on the reported and actual statistical significance of laser and radiofrequency studies that is often contradictory, on both skin repair and hair growth. Some RF and laser studies postulate short-term improvement on skin repair, and substantial results on hair health, but without following up to control for adverse side effects, effects reversal or reoccurrence or certain skin disorders such as pigmentation which generally reoccur following laser or RF treatments. A main issue pertaining to such technologies is the results of inflammation. Laser and RF companies claim reduction of inflammation. Yet, a large body of research demonstrates significant inflammation increase after trauma-based procedures. A diligent evaluation of other methods and techniques is also conducted based on research and clinical studies presented, with inflammation being the centrepiece. Methods: In our randomized, double-blind longitudinal clinical research, we followed 22 clinical cases treated with a novel resonance anti-inflammatory technology for up to 4 years. Results: All subjects evidenced irreversible skin repair and hair growth. Results on hair were slower to appear and ranged from two weeks to one month before observing the full effect. The number of treatments required for substantial repair depended on the chronicity and severity of skin condition, and the extent of hair loss, rather than age. More chronic, difficult cases required more treatments irrespective of whether the subject was younger or older. These results on age-independent skin repair and hair growth advocated for the importance of anti-inflammatory techniques to counterbalance immune insufficiency, age-accumulated oxidative stress, and disrupted cellular communications. Conclusions: Focus should be shifted from the immediacy of results to the long-term effects of the results with respect to evaluating different treatment modalities on skin repair and hair growth. Inflammation is one of the main reasons for both aging and disease. In assessing the efficacy of a technology, it is important to diligently look for evidence pertinent to the absence of inconspicuous, or insidiously forming inflammation following the procedure, a perspective that most published and unpublished clinical studies fail to consider, since they do not test for inflammatory interleukins or levels of the C-reactive protein that would evidence the presence of inflammation.

Harnessing the Power of Exosome Therapy in Dermatology: Current Insights and Future Directions

Exosomes, extracellular vesicles containing bioactive molecules such as proteins, lipids, and nucleic acids, have emerged as promising candidates for innovative therapeutic approaches in dermatology. This review examines recent advancements in exosome-based therapies for various dermatological conditions, including wound healing, hair regeneration, and inflammatory skin disorders. A literature review was conducted using PubMed, searching the keywords "exosome therapy dermatology,” “exosome therapy skin conditions,” "exosome therapy wound healing,” "exosome therapy skin inflammation," "exosome therapy hair regeneration," "exosome-based therapeutics", and "exosome formulation." A total of 41 articles were screened for this review. Current research demonstrates the potential of exosomes derived from stem cells, keratinocytes, and fibroblasts in modulating cellular signaling pathways, promoting tissue repair, and regulating immune responses. Moreover, exosome-based formulations offer advantages such as targeted delivery, low immunogenicity, and enhanced stability. Future directions in exosome therapy include optimizing isolation and purification techniques, elucidating mechanisms of action, and exploring novel sources of therapeutic exosomes. Additionally, clinical trials are warranted to evaluate the safety, efficacy, and long-term outcomes of exosome-based treatments, paving the way for personalized and regenerative dermatology.

A Review on Herbal Components used for Polyherbal Facewash

Cosmetics, derived from the Greek word "kosmetikos," are substances used to enhance, cleanse, and promote attractiveness. Face wash has evolved to address various skin concerns, including acne and aging. Herbal cosmetics, utilizing plant-based products, offer aesthetically pleasing physiological effects such as skin healing and smoothening. Their mild and non-toxic nature, along with natural ingredients like oils and extracts, contribute to their benefits. They are rich in nutrients, environmentally friendly, and economically viable, making them a preferred choice for consumers seeking natural alternatives The skin's multi-layered structure, including the epidermis, dermis, and hypodermis, plays a crucial role in protecting against external threats, regulating body temperature, and preserving moisture. Face wash products serve therapeutic purposes, including antimicrobial, anti-inflammatory, anti-acne, and antioxidant properties. Herbal face wash products, derived from various botanical families, contribute to their therapeutic and aesthetic properties. The integration of various herbs such as Aloe vera, Rosemary, Buckwheat seeds, Betel-nut palm, Calendula, Babchi, Burdock root, Chia, Sacha inchi, and Jojoba oil into face wash formulations further enriches the landscape. In summary, this literature review provides a comprehensive understanding of herbal cosmetics, the formulation of face wash products, their benefits, and therapeutic applications.

An antimicrobial microneedle patch promotes functional healing of infected wounds through controlled release of adipose tissue-derived apoptotic vesicles

The high incidence and mortality rates associated with acute and chronic wound infections impose a significant burden on global healthcare systems. In terms of the management of wound infection, the reconstruction and regeneration of skin appendages are essential for the recovery of mechanical strength and physiological function in the regenerated skin tissue. Novel therapeutic approaches are a requisite for enhancing the healing of infected wounds and promoting the regeneration of skin appendages. Herein, a novel antimicrobial microneedle patch has been fabricated for the transdermal controlled delivery of adipose tissue-derived apoptotic vesicles (ApoEVs-AT@MNP) for the treatment of infected wounds, which is expected to achieve high-quality scarless healing of the wound skin while inhibiting the bacteria in the infected wound. The microneedle patch (MNP) system possesses adequate mechanical strength to penetrate the skin, allowing the tips to remain inside tissue for continuous active release of biomolecules, and subsequently degrades safely within the host body. In vivo transplantation demonstrates that ApoEVs-AT@MNP not only inhibits bacterial proliferation in infected wounds but also significantly promotes effective and rapid scarless wound healing. Particularly noteworthy is the ability of ApoEVs-AT@MNP to promote the rapid formation of mature, evenly arranged hair follicles in infected wounds, observed as early as 8 days following implantation, which is essential for the restoration of skin function. This rapid development of skin appendages has not been reported this early in previous studies. Therefore, ApoEVs-AT@MNP has emerged as an excellent, painless, non-invasive, and highly promising treatment for infected wounds.

Molecular farming expression of recombinant fusion proteins applied to skincare strategies.

This review discusses the current research progress in molecular farming technology in the field of skincare, with an emphasis on molecular farming expression strategies. The strategies of transdermal drug delivery and their advantages are also highlighted. The expression of cosmetically relevant fused proteins has become an important way to enhance the efficacy of the proteins. Therefore, we also discuss the feasibility and strategies for expressing fusion proteins in A. thaliana, specifically the fusion of Epidermal growth factor (EGF) to a cell-penetrating peptide (CPP), in which the production can be greatly enhanced via plant expression systems since these systems offer higher biosecurity, flexibility, and expansibility than prokaryotic, animal and mammalian expression systems. While the fusion of EGF to CCP can enhance its transdermal ability, the effects of the fusion protein on skin repair, melasma, whitening, and anti-aging are poorly explored. Beyond this, fusing proteins with transdermal peptides presents multiple possibilities for the development of tissue repair and regeneration therapeutics, as well as cosmetics and beauty products. As certain plant extracts are known to contain proteins beneficial for skin health, the expression of these proteins in plant systems will better maintain their integrity and biological activities, thereby facilitating the development of more effective skincare products.

Carboxymethyl chitosan/polyacrylamide double network hydrogels based on hydrogen bond cross-linking as potential wound dressings for skin repair

An ideal biomedical hydrogel should imitate natural tissues with high water absorption, high toughness and superior biocompatibility. However, hydrogels constructed from biomolecules such as polysaccharides have low mechanical strength and limited applications. Based on carboxymethyl chitosan (CMCS) and polyacrylamide (PAM), a facile process is presented for preparing double network hydrogels (CMCS/PAM) with improved mechanical properties. According to the systematic characterization, carboxymethyl chitosan and polyacrylamide form a double network hydrogel through hydrogen bonding. The introduction of carboxymethyl chitosan alters the microscopic structure of PAM hydrogel, resulting in a consistent porosity pattern. Hydrogels with double networks exhibit high tensile properties, high stiffness, and good energy dissipation. Furthermore, the hydrogel exhibits effective adhesion to other hydrophilic surfaces. The CMCS/PAM network hydrogels possess excellent properties such as high swelling capacity, injectability, and cellular biocompatibility, making them potentially valuable for biomedical applications.

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.

Preparation of sulfated arabinogalactan-loaded hydrogel for wound healing in mouse burn model

Sulfation of polysaccharides can affect their biological activity by introducing sulfate groups. Skin burns occur regularly and have a great impact on normal survival. In this study, sulfated arabinogalactan (SAG) was prepared by sulfation, and polyvinyl alcohol (PVA) was used to prepare hydrogels for the treatment of scalded skin in mouse. The results show that the main chain of SAG consists of →3-β-D-Galactose (Gal)-(1, →3, 6)-β-D-Gal-(1 and →4)-β-d-Glucose (Glc)-(1. The chain is a neutral polysaccharide composed of T-β-L-Arabinose (Araf)-(1→, with a molecular weight of 17.9 kDa. At the same time, PVA + SAG hydrogel can promote the scald repair of mouse skin by promoting collagen deposition and angiogenesis, and regulating the TLR4/MyD88/NF-κB signaling pathway. Interestingly, the effect of SAG on promoting the repair of scald wounds is enhanced after AG is derivatized by sulfation. Therefore, the preparation of SAG by sulfation can promote scald repair, and has great application potential in the field of food and medicine.

Light‐Activated Nanocatalyst for Precise In‐Situ Antimicrobial Synthesis via Photoredox‐Catalytic Click Reaction

AbstractThe excessive and prolonged use of antibiotics contributes to the emergence of drug‐resistant S. aureus strains and potential dysbacteriosis‐related diseases, necessitating the exploration of alternative therapeutic approaches. Herein, we present a light‐activated nanocatalyst for synthesizing in situ antimicrobials through photoredox‐catalytic click reaction, achieving precise, site‐directed elimination of S. aureus skin infections. Methylene blue (MB), a commercially available photosensitizer, was encapsulated within the CuII‐based metal–organic framework, MOF‐199, and further enveloped with Pluronic F‐127 to create the light‐responsive nanocatalyst MB@PMOF. Upon exposure to red light, MB participates in a photoredox‐catalytic cycle, driven by the 1,3,5‐benzenetricarboxylic carboxylate salts (BTC−) ligand presented in the structure of MOF‐199. This light‐activated MB then catalyzes the reduction of CuII to CuI through a single‐electron transfer (SET) process, efficiently initiating the click reaction to form active antimicrobial agents under physiological conditions. Both in vitro and in vivo results demonstrated the effectiveness of MB@PMOF‐catalyzed drug synthesis in inhibiting S. aureus, including their methicillin‐resistant strains, thereby accelerating skin healing in severe bacterial infections. This study introduces a novel design paradigm for controlled, on‐site drug synthesis, offering a promising alternative to realize precise treatment of bacterial infections without undesirable side effects.

Light-Activated Nanocatalyst for Precise In-Situ Antimicrobial Synthesis via Photoredox-Catalytic Click Reaction.

The excessive and prolonged use of antibiotics contributes to the emergence of drug-resistant S. aureus strains and potential dysbacteriosis-related diseases, necessitating the exploration of alternative therapeutic approaches. Herein, we present a light-activated nanocatalyst for synthesizing in situ antimicrobials through photoredox-catalytic click reaction, achieving precise, site-directed elimination of S. aureus skin infections. Methylene blue (MB), a commercially available photosensitizer, was encapsulated within the CuII-based metal-organic framework, MOF-199, and further enveloped with Pluronic F-127 to create the light-responsive nanocatalyst MB@PMOF. Upon exposure to red light, MB participates in a photoredox-catalytic cycle, driven by the 1,3,5-benzenetricarboxylic carboxylate salts (BTC-) ligand presented in the structure of MOF-199. This light-activated MB then catalyzes the reduction of CuII to CuI through a single-electron transfer (SET) process, efficiently initiating the click reaction to form active antimicrobial agents under physiological conditions. Both in vitro and in vivo results demonstrated the effectiveness of MB@PMOF-catalyzed drug synthesis in inhibiting S. aureus, including their methicillin-resistant strains, thereby accelerating skin healing in severe bacterial infections. This study introduces a novel design paradigm for controlled, on-site drug synthesis, offering a promising alternative to realize precise treatment of bacterial infections without undesirable side effects.