Full-thickness Injury Research Articles

On-demand engineered double-network gelatin/silicate composited hydrogels with enhanced wet adhesion and stable release of bioactive ion for promoting wound healing

Silicate bioceramics have demonstrated great potential in hydrogel dressings for wound healing due to their special origins of promoting endothelial cell angiogenesis and inhibiting apoptosis of cardiomyocyte. However, there are still some deficiencies, such as insufficient biological activity, instability of silicate ion release, and lower wet adhesion on wounds with tissue exudate, limiting their further clinical applications. Herein, inspired by mussels, a multifunctional double-network hydrogel (FS/PAM-Gel-PDA) wound dressing composited gelatin with silicate ceramic powder with satisfactory wet adhesion, stable release of bioactive ions, hemostasis, and the ability of promoting vascular regeneration was engineered through specifically grafting dopamine to gelatin and introducing ferrous silicate ceramic powder into the hydrogel. The comprehensive experimental results substantiate that the FS/PAM-Gel-PDA has wet-adhesion strength of up to 21.78 kPa, and remains stably adherent to porcine myocardial tissues intuitively after bending, twisting, soaking in water, and stretching. The test results of ion release behavior in vitro show that the oxidation and agglomeration of ferrous silicate ceramic powder can be effectively inhibited by using dopamine to form an antioxidant layer on the surface of ceramic powder, and thus, the stable release of Fe2+ and SiO44− effective ions can be realized. The animal experiment exhibits that FS/PAM-Gel-PDA can achieve rapid hemostasis in the lethal liver defect model. Meanwhile, the FS/PAM-Gel-PDA reveals the remarkable ability to promote wound healing in a full-thickness skin injury model, which can obviously accelerate skin re-epithelialization. To sum up, the FS/PAM-Gel-PDA has excellent wet adhesion and stable release of active ions to accelerate angiogenesis, which shows great potential in promoting wound healing.Graphical

Biological attributes required for epidermal regeneration: Evaluation of the next-generation autologous cell harvesting device.

Early wound intervention and closure is critical for reducing infection and improving aesthetic and functional outcomes for patients with acute burn wounds and nonthermal full-thickness skin defects. Treatment of partial-thickness burns or full-thickness injuries with autologous skin cell suspension (ASCS) achieves robust wound closure while limiting the amount of donor skin compared with standard autografting. A Next Generation Autologous Cell Harvesting Device (NG-ACHD) was developed to standardize the preparation process for ASCS to ensure biological attributes are obtained known to correlate with well-established safety and performance data. This study compared ASCS prepared using the NG-ACHD and ACHD following the manufacturer's guidance, evaluating cellular yields, viability, apoptotic activity, aggregates, phenotypes and functional capacity. Non-inferiority was established for all biological attributes tested and comparable healing trajectories were demonstrated using an in vitro skin regeneration model. In addition to standardization, the NG-ACHD also provides workflow efficiencies with the potential to decrease training requirements and increase the ease of incorporation and utilization of ASCS in clinical practice.

Human umbilical cord mesenchymal stem cells combined with porcine small intestinal submucosa promote the healing of full-thickness skin injury in SD rats.

Aim: To assess the therapeutic potential of human umbilical cord mesenchymal stem cells (hUCMSCs) combined with porcine small intestinal submucosa (SIS) on full-thickness skin injuries in rats. Methods: We established full-thickness skin injury models in Sprague-Dawley rats, dividing them into blank control, SIS, hUCMSCsand hUCMSCs combined with SIS. We monitored wound healing, scoresand area, and analyzed inflammatory cells, microvessel densityand collagen fibers after 12days. Results: The blank group showed no healing, forming a scar of 0.6×0.5cm2, while SIS and hUCMSCs groups exhibited incomplete healing with 0.4×0.5cm2 scabs. Wound healing was significantly better in the hUCMSCs combined with the SIS group. Conclusion: Local application of hUCMSCs combined with SIS enhances full-thickness skin injury wound healing in rats.

Development of a Combat-Relevant Murine Model of Wound Mucormycosis: A Platform for the Pre-Clinical Investigation of Novel Therapeutics for Wound-Invasive Fungal Diseases.

Wound-invasive fungal diseases (WIFDs), especially mucormycosis, have emerged as life-threatening infections during recent military combat operations. Many combat-relevant fungal pathogens are refractory to current antifungal therapy. Therefore, animal models of WIFDs are urgently needed to investigate new therapeutic solutions. Our study establishes combat-relevant murine models of wound mucormycosis using Rhizopus arrhizus and Lichtheimia corymbifera, two Mucorales species that cause wound mucormycosis worldwide. These models recapitulate the characteristics of combat-related wounds from explosions, including blast overpressure exposure, full-thickness skin injury, fascial damage, and muscle crush. The independent inoculation of both pathogens caused sustained infections and enlarged wounds. Histopathological analysis confirmed the presence of necrosis and fungal hyphae in the wound bed and adjacent muscle tissue. Semi-quantification of fungal burden by colony-forming units corroborated the infection. Treatment with liposomal amphotericin B, 30 mg/kg, effectively controlled R. arrhizus growth and significantly reduced residual fungal burden in infected wounds (p < 0.001). This study establishes the first combat-relevant murine model of wound mucormycosis, paving the way for developing and evaluating novel antifungal therapies against combat-associated WIFDs.

Spleen autotransplantation on liver versus greater omentum for simultaneous injuries of liver and spleen: an experimental study.

In a simulated situation of simultaneous spleen and liver trauma, we aimed to compare the outcomes of treating both injuries with spleen autotransplantation on the omentum (SAO) alongside hepatorrhaphy versus spleen autotransplantation as a patch on the liver parenchyma. A total of 24 rats were separated into two groups: the SAO and the spleen autotransplantation on the liver. They underwent a uniform and simultaneous procedure involving full-thickness injuries to the left lobe of the liver and grade 4 spleen injuries. We measured hemoglobin, white blood cell (WBC), complement (C3 and C4), and immunoglobulin G, M, and A (IgG, IgM, IgA) levels before and 4 weeks after the surgery. We utilized Technetium-99m scintigraphy to evaluate the posttransplant splenic graft functions 4 weeks after the surgery. The two groups had no significant difference in the hematologic and immunologic factors before surgery. However, both procedures significantly reduced hemoglobin, C3, IgG, and IgA levels (all P<0.05). WBC counts significantly increased in the SAO group, whereas the IgM level decreased after the intervention (P<0.05). WBC was increased in the SAO group, while IgM and IgA were decreased in the SAO group. The Technetium uptake was similar between the two groups (P=0.3). In simultaneous spleen and liver injuries, the autotransplantation of splenic into the liver parenchyma appears to be a promising surgical approach for preserving spleen function and hepatorrhaphy at the same time instead of doing them separately.

Development of a multifunctional nano-hydroxyapatite platform (nHEA) for advanced treatment of severely infected full-thickness skin wounds

The treatment of full-thickness skin injuries complicated by severe infection is hampered by the lack of comprehensive solutions that can regulate the various stages of wound healing. Consequently, there is an urgent need for a multifunctional dressing capable of multi-level regulation. In this study, we propose a novel solution by covalently integrating ε-poly-l-lysine-grafted gallic acid (EG) and in situ bioreduced silver nanoparticles (AgNPs) onto nano-hydroxyapatite (nHAP), thereby developing a multi-layered, multifunctional nanoplatform (nHEA). Cell experiments have shown that, compared to nHAP and nHAP loaded only with EG (nHEG), the addition of AgNPs to nHEA confers excellent antibacterial properties while maintaining optimal biocompatibility. The incorporation of EG onto nHEG and nHEA imparts antioxidation, anti-inflammatory, and pro-angiogenic functions, and the release of Ca2+ and EG further enhances fibroblast migration and collagen secretion. In a rat model of full-thickness skin injury with severe infection, nHEA demonstrates remarkable antibacterial and anti-inflammatory effects, along with promoting collagen remodeling and regeneration. Together, both cell experiments and animal studies confirm the significant potential of this innovative multifunctional nanoplatform in the treatment of full-thickness skin injuries with severe infection. Statement of significanceTreating infected full-thickness skin injuries poses a longstanding challenge due to the lack of comprehensive solutions that can regulate different stages of wound healing. This study introduces a novel multifunctional nanoplatform, nHEA, developed by covalently integrating ε-poly-l-lysine grafted with gallic acid (EG) and in situ bioreduced AgNPs onto nano-hydroxyapatite (nHAP). Cell experiments reveal that the integration of AgNPs enhances nHEA's antibacterial performance while maintaining optimal biocompatibility. The inclusion of EG bestows antioxidant, inflammation-regulating, and angiogenetic properties upon nHEA, and the release of Ca2+ and EG stimulates the migration and collagen secretion of fibroblast cells. Consequently, nHEA exhibits superior antibacterial and inflammation-regulating efficacy, and stimulates collagen remodeling and regeneration in vivo, making it a promising treatment for severely infected skin injuries.

A Case Report of Spontaneous Gastric Perforation in Newborns

Spontaneous gastric perforation is a serious, rare and life threatening condition. Perforation of the stomach is a full thickness injury to the wall of the organ. As the peritoneum completely covers the stomach, perforation of the wall creates a communication between the gastric lumen and the peritoneal cavity. Gastric perforation is caused by three different mechanisms. We report a case of gastric perforation in a Preterm, very low birth weight neonate in our NICU and based on the signs of abdominal distension and increased abdominal girth. Abdomen ultrasonography and Contrast dye study was done which showed perforation, following which exploratory laparotomy was performed and surgical repair was carried out. As it has high mortality rate so its prompt recognition and surgical intervention is utmost necessary

764 Burn Advanced Practice Provider Fluorescein Dye Staining Reduces Ophthalmology Consults

Abstract Introduction Facial burn injury patients typically receive ophthalmology consultations irrespective of the severity of their peri-ocular or ocular involvement. Minor facial burns without significant eye involvement or ocular complaints often do not require in-patient ophthalmologist assessment. We sought to assess ocular fluorescein dye staining by burn unit Advanced Practice Providers (APP; Physician Assistants and Nurse Practitioners) to decrease unnecessary ophthalmology consults. Methods A prospective evaluation was performed at our ABA-verified burn center for all facial burn injury patients admitted between January 1 through August 31, 2023. Patients who presented with full-thickness injuries to their eyelids or peri-ocular area, those exhibiting tense eyelids raising concern for ocular compartment syndrome, those with severe eye pain and anyone with acute vision loss were excluded from staining and received an immediate ophthalmology consult. For patients with facial burns who did not meet the aforementioned criteria, fluorescein dye stains were administered upon admission by APPs, if available. Ophthalmology consults were only ordered for patients with positive stains. Results 83 patients were admitted with facial burns between January 1 and August 31, 2023. Of these, 42 patients received fluorescein dye stains by APPs. Among those stained, 79% were male and 21% female. The average age was 49 years old (range 19 to 82). The average TBSA affected was 8.46% (range 0.1% to 38.5%). The majority of patients (83%) had flame/flash burns, 7% had scald burns, 2% had chemical burns, 2% had sun burns and the remainder had unclear etiology. 34 patient dye stains (80%) yielded negative results, obviating the need for an ophthalmology consult. The remaining 8 had positive results, necessitating a consult. Among these, 4 were false positives with no ocular injury found by ophthalmology. The remaining 4 exhibited ocular chemosis, trace punctate epithelial erosions, thermal keratopathy and chronic central epithelial defects from prior Lasik surgery. Ophthalmology was consulted in 37 out of 83 patients, with only 8 consults resulting from APP staining. This signifies a 48% overall reduction in consults placed during this 8-month time frame, and an 80% reduction of consults in whom qualified for the pathway. Conclusions Fluorescein dye staining by burn unit APPs minimizes unnecessary ophthalmology consults, likely reducing healthcare costs for patients and healthcare facilities. Applicability of Research to Practice Burn centers should consider fluorescein dye stain screening as part of routine practice for burn patients.

Response of Articular Cartilage to Hyperosmolar Stress: Report of an Ex Vivo Injury Model

Background: Physiological 0.9% saline is commonly used as an irrigation fluid in modern arthroscopy. There is a growing body of evidence that a hyperosmolar saline solution has chondroprotective effects, especially if iatrogenic injury occurs. Purpose: To (1) corroborate the superiority of a hyperosmolar saline solution regarding chondrocyte survival after mechanical injury and (2) observe the modulatory response of articular cartilage to osmotic stress and injury. Study Design: Controlled laboratory study. Methods: Osteochondral explants were isolated from bovine stifle joints and exposed to either 0.9% saline (308 mOsm) or hyperosmolar saline (600 mOsm) and then damaged with a sharp dermatome blade to attain a confined full-thickness cartilage injury site, incubated in the same fluids for another 3 hours, and transferred to chondropermissive medium for further culture for 1 week. Chondrocyte survival was assessed by confocal imaging, while the cellular response was evaluated over 1 week by relative gene expression for apoptotic and inflammatory markers and mediator release into the medium. Results: The full-thickness cartilage cut resulted in a confined zone of cell death that mainly affected superficial zone chondrocytes. Injured samples that were exposed to hyperosmolar saline showed less expansion of cell death in both the axial (P < .007) and the coronal (P < .004) plane. There was no progression of cell death during the following week of culture. Histological assessment revealed an intact cartilage matrix and normal chondrocyte morphology. Inflammatory and proapoptotic genes were upregulated on the first days postexposure with a notable downregulation toward day 7. Mediator release into the medium was concentrated on day 3. Conclusion: This in vitro cartilage injury model provides further evidence for the chondroprotective effect of a hyperosmolar saline irrigation fluid, as well as novel data on the capability of articular cartilage to quickly regain joint homeostasis after osmotic stress and injury. Clinical Relevance: Raising the osmolarity of an irrigating solution may be a simple and safe strategy to protect articular cartilage during arthroscopic surgery.

Interferon-gamma signaling promotes cartilage regeneration after injury

Osteoarthritis is a common chronic disease and major cause of disability and chronic pain in ageing populations. In this pathology, the entire joint is involved, and the regeneration of articular cartilage still remains one of the main challenges. Here, we investigated the molecular mechanisms underlying cartilage regeneration in young mice using a full-thickness cartilage injury (FTCI) model. FTCI-induced cartilage defects were created in the femoral trochlea of young and adult C57BL/6 mice. To identify key molecules and pathways involved in the early response to cartilage injury, we performed RNA sequencing (RNA-seq) analysis of cartilage RNA at 3 days after injury. Young mice showed superior cartilage regeneration compared to adult mice after cartilage injury. RNA-seq analysis revealed significant upregulation of genes associated with the immune response, particularly in the IFN-γ signaling pathway and qRT-PCR analysis showed macrophage polarization in the early phase of cartilage regeneration (3 days) in young mice after injury, which might promote the removal of damaged or necrotic cells and initiate cartilage regeneration in response to injury. IFN-γR1- and IFN-γ-deficient mice exhibited impaired cartilage regeneration following cartilage injury. DMM-induced and spontaneous OA phenotypes were exacerbated in IFN-γR1−/− mice than in wild-type mice. Our data support the hypothesis that IFN-γ signaling is necessary for cartilage regeneration, as well as for the amelioration of post-traumatic and age-induced OA.

Effect of Caffeic Acid Phenethyl Ester on Wound Healing: A Systematic Review

Caffeic acid, a naturally occurring organic compound, possesses antioxidant and anti-inflammatory properties, along with its derivatives. This systematic review aimed to evaluate the effect of caffeic acid and its derivatives on oxidative stress and inflammatory response in cutaneous wound healing. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Searches were performed in PubMed, Scopus, and Ovid MEDLINE. Articles published between 2000 and June 2022, with seven articles meeting the inclusion criteria were retrieved. The articles constituted in-vivo studies that utilised caffeic acid phenethyl ester (CAPE) as the therapeutic agent in three types of cutaneous wound including full-thickness burn injury (n=4), two incisional wounds, and one pressure ulcer. CAPE scavenged reactive oxidative species and reduced lipid peroxidation, superoxide dismutase, nitrotyrosine, malondialdehyde, catalase, xanthine oxidase, and nitric oxide levels. The treated injured area revealed enhanced granulation tissue formation, vascularisation, and collagenisation as well as long-term effects of CAPE as evidenced by reduced myofibroblast amount, CD68-positive macrophages, and increased collagen deposition. The systematic review emphasised how antioxidant and anti-inflammatory effects of CAPE could improve the process of wound healing, suggesting its substantial potential for clinical applications in this domain.

Hydrogel Loaded with Peptide-Containing Nanocomplexes: Symphonic Cooperation of Photothermal Antimicrobial Nanoparticles and Prohealing Peptides for the Treatment of Infected Wounds.

Current treatment for chronic infectious wounds is limited due to severe drug resistance in certain bacteria. Therefore, the development of new composite hydrogels with nonantibiotic antibacterial and pro-wound repair is important. Here, we present a photothermal antibacterial composite hydrogel fabricated with a coating of Fe2+ cross-linked carboxymethyl chitosan (FeCMCS) following the incorporation of melanin nanoparticles (MNPs) and the CyRL-QN15 peptide. Various physical and photothermal properties of the hydrogel were characterized. Cell proliferation, migration, cycle, and free-radical scavenging activity were assessed, and the antimicrobial properties of the hydrogel were probed by photothermal therapy. The effects of the hydrogel were validated in a model of methicillin-resistant Staphylococcus aureus (MRSA) infection with full-thickness injury. This effect was further confirmed by changes in cytokines associated with inflammation, re-epithelialization, and angiogenesis on the seventh day after wound formation. The MNPs demonstrated robust photothermal conversion capabilities. The composite hydrogel (MNPs/CyRL-QN15/FeCMCS) promoted keratinocyte and fibroblast proliferation and migration while exhibiting high antibacterial efficacy, effectively killing more than 95% of Gram-positive and Gram-negative bacteria. In vivo study using an MRSA-infected full-thickness injury model demonstrated good therapeutic efficacy of the hydrogel in promoting regeneration and remodeling of chronically infected wounds by alleviating inflammatory response and accelerating re-epithelialization and collagen deposition. The MNPs/CyRL-QN15/FeCMCS hydrogel showed excellent antibacterial and prohealing effects on infected wounds, indicating potential as a promising candidate for wound healing promotion.

Compound Microalgae-Type Biofunctional Hydrogel for Wound Repair during Full-Thickness Skin Injuries.

A dual biofunctional hydrogel (HQCS-SP) wound dressing, offering antibacterial properties and a biological response, was innovatively designed and developed to repair full-layer skin defects. The HQCS-SP hydrogel creates an artificial matrix that facilitates cell recruitment, extracellular matrix deposition, exhibiting exceptional tissue affinity, robust self-healing, effective hemostatic capabilities and accelerates wound healing. It is synthesized by crosslinking modified chitosan (HQCS) with spirulina protein (SP) and Fe3+. The HQCS provides antibacterial, antioxidant, good tissue affinity and excellent hemostasis performance. The incorporation of SP not only reinforces the antioxidant, antibacterial, anti-inflammatory, and pro-angiogenesis effects but also participates in the regulation of signal pathways and promotes wound healing. Therefore, this study offers a new visual angle for the design of advanced functional trauma dressings with great application potential in the bio-medical field.

Application of Meek micro-grafting technique in severe burn injury: a case report

Wound closure is often a challenge in patients with major burns due to the limited amount of healthy skin available for harvesting and grafting. As a result, this often yields severe morbidity and mortality amongst said patients. This case report presents the successful use of the Meek micro-grafting technique on a patient with extensive major deep dermal to full-thickness burn injuries in the Burn Unit of the Kuala Lumpur Hospital of Malaysia. The Meek micro-grafting method, involves the creation of micro-grafts from a small and limited donor site, and proved to be effective in promoting wound healing and minimizing donor site morbidity.

Dysfunctional latent transforming growth factor β activation after corneal injury in a classical Ehlers–Danlos model

Patients with classical Ehlers Danlos syndrome (cEDS) suffer impaired wound healing and from scars formed after injuries that are atrophic and difficult to close surgically. Haploinsufficiency in COL5A1 creates systemic morphological and functional alterations in the entire body. We investigated mechanisms that impair wound healing from corneal lacerations (full thickness injuries) in a mouse model of cEDS (Col5a1+/−). We found that collagen V reexpression in this model is upregulated during corneal tissue repair and that wound healing is delayed, impaired, and results in large atrophic corneal scars. We noted that in a matrix with a 50 % content of collagen V, activation of latent Transforming Growth Factor (TGF) β is dysregulated. Corneal myofibroblasts with a haploinsufficiency of collagen V failed to mechanically activate latent TGF β. Second harmonic imaging microscopy showed a disorganized, undulated, and denser collagen matrix in our Col5a1+/- model that suggested alterations in the extracellular matrix structure and function. We hypothesize that a regenerated collagen matrix with only 50 % content of collagen V is not resistant enough mechanically to allow adequate activation of latent TGF β by fibroblasts and myofibroblasts.

Effectiveness of Dermal Regeneration Templates in Managing Acute Full-thickness and Deep Dermal Burn Injuries: A Comparison with Split-thickness Skin Grafts.

The therapeutic challenge of managing acute full-thickness burns is significantly ameliorated with the introduction of dermal regeneration templates (DRTs). However, an updated synthesis of evidence-based data on the efficacy and safety of different DRTs is required. This systematic review and meta-analysis conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines aims to evaluate the role of various DRTs in comparison with split-thickness skin grafting in managing acute burn injuries after excision and debridement. A total of 28 randomized clinical trials were assessed, encompassing a wide array of DRTs. The study outcomes pointed to the diverse effectiveness of DRTs, with Integra demonstrating peripheral nerve reinnervation potential and TransCyte promoting rapid re-epithelialization. Some DRTs showed scar formation and skin quality comparable to those of autologous skin grafts. In terms of wound infection, certain treatments, including TransCyte, exhibited a significantly low infection rate. The evaluation of scar quality suggested that various interventions produced acceptable or improved outcomes without hypertrophic scarring. Recovery rates after the interventions displayed a range, with certain treatments showing rapid recovery and satisfactory results. The current systematic review points to the potential benefits of DRTs in managing burn wounds. Further research is necessary to shed light on the long-term impacts of these interventions on wound healing, scar quality, and patient recovery.

Asymmetric adhesive SIS-based wound dressings for therapeutically targeting wound repair

Severe tissue injuries pose a significant risk to human health. Conventional wound dressings fall short in achieving effective tissue regeneration, resulting in suboptimal postoperative healing outcomes. In this study, an asymmetric adhesive wound dressing (marked as SIS/PAA/LAP) was developed, originating from acrylate acid (AA) solution with laponite (LAP) nanoparticles polymerization and photo-crosslinked on the decellularized extracellular matrix small intestinal submucosa (SIS) patch. Extensive studies demonstrated that the SIS/PAA/LAP exhibited higher tissue adhesion strength (~ 33 kPa) and burst strength (~ 22 kPa) compared to conventional wound dressings like Tegaderm and tissue adhesive products. Importantly, it maintained favorable cell viability and demonstrated robust angiogenic capacity. In animal models of full-thickness skin injuries in rats and skin injuries in Bama miniature pigs, the SIS/PAA/LAP could be precisely applied to wound sites. By accelerating the formation of tissue vascularization, it displayed superior tissue repair outcomes. This asymmetrically adhesive SIS-based patch would hold promising applications in the field of wound dressings.

GelMA - PVAMA hydrogel loaded with MYDGF accelerates wound healing by promoting angiogenesis

Angiogenesis within the wound site is a necessary prerequisite for skin tissue regeneration during the process of wound healing. Skin vessels provide adequate nutrients and soluble bioactive factors to the wounded area and remove metabolites. In this study, we prepared a double-cross-linked hydrogel based on GelMA and PVAMA to load Myeloid-derived growth factor (MYDGF). Additionally, we evaluated the healing-promoting effect of the hydrogel using a full-thickness skin injury mouse model. Compared with the control and MYDGF-free hydrogels, the MYDGF-loaded hydrogels significantly increased the percentage of wound healing and promoted granulation tissue proliferation and epidermization. In vitro experiments have shown that MYDGF may augment the migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) by upregulating the expression of phosphorylated ERK and phosphorylated P38. These findings indicate that MYDGF-loaded hydrogels promote wound healing by accelerating angiogenesis.

Phosvitin-based hydrogels prepared in AmimCl under magnetic field treatment: Structural characteristics, biological functions, and application in skin wound healing

Due to the serious bacterial infection of skin and the waste of petroleum-based materials, there is an urgent need to develop natural biodegradable wound dressings with high antibacterial activity. Phosvitin (PSV) has shown its natural antioxidant and antibacterial properties, making it an excellent material for preparing wound healing dressings. In this study, we investigated the effect of magnetic field on the preparation of PSV-Microcrystalline Cellulose (MCC) composite hydrogels in 1-Allyl-3-methylimidazolium chloride (AmimCl) system. The results showed that the prepared hydrogels exhibited homogeneous surface structure, suitable swelling capacity and elasticity modulus, and sufficient thermal stability. The excellent antibacterial and antioxidant activities of hydrogels were mainly resulting from AmimCl and PSV, respectively, and the properties were enhanced after magnetic field treatment. The proteomics analysis indicated that AmimCl can readily penetrate the biological membranes of Staphylococcus aureus (S. aureus), upsetting the metabolism and reducing the virulence. The hydrogels showed great blood compatibility. Compared with the commercial materials, the 5 mT-treated hydrogels presented a comparable wound healing rate in the full-thickness skin injury model. On day 7, the wound healing rate of the 5 mT group reached approximately 84.40 %, which was significantly higher than that of the control group, 72.88 % (P < 0.05). In conclusion, our work provides experience for the development of biodegradable materials combined in ionic liquids and magnetic field, and explores their applications in wound healing dressings.

A bioactive composite hydrogel dressing that promotes healing of both acute and chronic diabetic skin wounds

Mesenchymal stem cell derived exosomes (MSC-Exos) demonstrate beneficial effects on wound healing via anti-inflammatory and angiogenic properties. Chitosan (CS) exhibits excellent biocompatibility and accelerates cellular migration, adhesion, and proliferation. The ions released from bioactive glass (BG) and titanium dioxide (TiO2) nanoparticles exhibit sustained angiogenic and antibacterial potency. In this study, CMCS-CEBT hydrogel was synthesized from exosomes encapsulated carboxymethyl chitosan (CMCS), chitosan nanoparticles (CS-NPs), BG, and TiO2 nanoparticles for a preliminary evaluation of its impacts on the treatment of full-thickness skin defects, diabetic wounds, and burn skin injury due to burns. In vitro analysis indicated that the hydrogel exhibits excellent cell compatibility, stimulates endothelial cell adhesion and proliferation, and presents anti-inflammatory, angiogenic, and antibacterial activities. In vivo, the composite hydrogel dressing accelerated a wound healing acceleration effect, stimulated angiogenesis, and increased collagen deposition and the expression of anti-inflammatory factors. This innovative composite hydrogel dressing as a potential clinical therapy, utilizing bioactive materials, holds promise as a potential clinical therapy that aims to facilitate the regeneration of acute and chronically damaged skin tissue.