Acute Wounds Research Articles

Nanotechnology-based Approaches for Efficient Wound Monitoring and Healing

Wound healing is a complex physiological process consisting of several biological and immunological mechanisms which are mutually inclusive. Wounds are commonly categorized as acute and chronic wounds. Acute wound healing is dynamic and chronic wound healing proceeds in a prolonged and irregular manner; thus, it calls for proper management. Certain problems associated to wound healing have triggered the researchers to come up with a promising approach and so nanotechnology-based approaches have evolved as a driving force in wound healing. Nanotechnology has led to the fabrication of nanoparticles, biomolecule loaded dressings and smart dressings to accelerate the wound healing. Nanobiosensors are also being developed which can monitor wound conditions with great precision and incredible sensitivity. This review concentrates on novel nanoscale approaches for instance, nanoparticles such as gold, silver, polystyrene, chitosan, zinc peroxide and nanomaterials such as nano-sensors, nanoflares, nanofibers, etc. for effective wound monitoring and healing. The efficacy of nanomaterial based therapeutic agents in wound healing has been expressed herein. The significance of nanoscale systems in wound healing in terms of anti-microbial activity, angiogenesis, drug delivery, collagen deposition and stem cell delivery has also been addressed.

PH-Responsive Wound Dressing Based on Biodegradable CuP Nanozymes for Treating Infected and Diabetic Wounds.

Nanozymes, emerging nanomaterials for wound healing, exhibit enzyme-like activity to modulate the levels of reactive oxygen species (ROS) at wound sites. Yet, the solo regulation of endogenous ROS by nanozymes often falls short, particularly in chronic refractory wounds with complex and variable pathological microenvironments. In this study, we report the development of a multifunctional wound dressing integrating a conventional alginate (Alg) hydrogel with a newly developed biodegradable copper hydrogen phosphate (CuP) nanozyme, which possesses good near-infrared (NIR) photothermal conversion capabilities, sustained Cu ion release ability, and pH-responsive peroxidase/catalase-mimetic catalytic activity. When examining acute infected wounds characterized by a low pH environment, the engineered Alg/CuP composite hydrogels demonstrated high bacterial eradication efficacy against both planktonic bacteria and biofilms, attributed to the combined action of catalytically generated hydroxyl radicals and the sustained release of Cu ions. In contrast, when applied to chronic diabetic wounds, which typically have a high pH environment, these composite hydrogels exhibit significant angiogenic performance. This is driven by the provision of catalytically generated dissolved oxygen and a beneficial supplement of Cu ions released from the degradable CuP nanozyme. Further, a mild thermal effect induced by NIR irradiation amplifies the catalytic activities and bioactivity of Cu ions, thereby enhancing the healing process of both infected and diabetic wounds. Our study validates that the synergistic integration of photothermal effects, catalytic activity, and released Cu ions can concurrently yield high antibacterial efficiency and tissue regenerative activity, rendering it highly promising for various clinical applications in wound healing.

Airbrushed nanofibers with bioactive core and antibacterial shell for wound healing application

Acute and chronic wounds are vulnerable to infection and delayed healing and require critical care and advanced wound protection. To overcome the challenges, dual therapy of antibacterial and growth factors will be a novel wound care strategy. The present study explores airbrushed core–shell nanofiber for dual delivery of epidermal growth factor (EGF) and amoxicillin (AMOX) in a sustained manner. A blend of polycaprolactone (PCL)-polyethylene oxide (PEO) was used to prepare the shell compartment for amoxicillin loading and poly-DL-lactide (PDLLA) core for EGF loading by using a customized airbrush setup. Characterization result shows a uniform distribution of nanofibers ranging between 200 and 500 nm in diameter. Amoxicillin loading in the shell compartment offers an initial burst release followed by a sustained release for up to 14 days. Whereas EGF in the core part shows a continuous sustained release throughout the release study.In-vitrostudy indicates the biocompatibility of EGF-AMOX loaded core–shell nanofibers with human dermal fibroblast cell (HDF) cells and a higher cellular proliferation compared to control samples. Gene expression data show an increase in fold change of collagen I and tropoelastin expression, indicating the regenerative properties of EGF-AMOX encapsulated nanofiber. The combination of bioactive core (EGF) and antibiotic shell (amoxicillin) in an airbrushed nanofibrous scaffold is a novel approach, which is the first time explored to deliver sustainable therapy to treat skin wounds. Our results demonstrate that PCL-PEO-Amoxicillin/PDLLA-EGF-loaded core–shell nanofibers are promising dual therapy scaffolds to deliver effective skin wound care, with the possibility of direct deposition on the wound.

Umbilical cord-derived mesenchymal stem cell secretome promotes skin regeneration and rejuvenation: From mechanism to therapeutics.

How to effectively repair cutaneous wounds and promote skin rejuvenation has always been a challenging issue for clinical medicine and medical aesthetics. Current conventional medicines exhibit several drawbacks, including limited therapeutic effects, prolonged treatment periods, and high costs. As a novel cell-free therapy, the umbilical cord-derived mesenchymal stem cell (UCMSC) secretome may offer a promising approach for skin regeneration and rejuvenation. The UCMSC secretome is a collection of all proteins secreted by mesenchymal stem cells, including conditioned media, exosomes, and other substances. The UCMSC secretome has numerous abilities to accelerate acute wound healing, including high fibroblast and keratinocyte proliferative activity, pro-angiogenesis, anti-inflammation, anti-fibrosis, and anti-oxidative stress. Its impact on the four stages of wound healing is manifested by inducing the haemostasis phase, inhibiting the inflammation phase, promoting the proliferation phase, and regulating the remodelling phase. Furthermore, it is highly effective in the treatment of chronic wounds, alopecia, aging, and skin homeostasis disturbance. This review focuses on the clinical therapies and application prospects of the UCMSC secretome, encompassing its source, culture, separation, identification, storage, and pretreatment. Additionally, a discussion on the dosage, administration route, efficacy, and biosafety in the clinical situation is presented. This review aims to provide scientific support for the mechanistic investigation and clinical utilisation of the UCMSC secretome in wound healing and skin rejuvenation.

High-Resolution Ultrasound Imaging for Non-Invasive Characterization of Acute Wound Healing in Radiation Injury on Guinea Pig Skin Tissue

Purpose: High-resolution ultrasound imaging is a non-invasive and objective appraisal. Ultrasound imaging accomplishes the target assessment and follow-up of radiation-induced skin injury.
 The study aimed to investigate the complete anatomical and structural alternations of acute wound healing in skin tissue radiation injury after cell therapy with high-frequency ultrasound imaging techniques.
 Materials and Methods: Female guinea pigs (250 g) were divided into 3 groups: (a) controls, consisting of non-treated guinea pigs; (b) radiation-treated; (c) radiation-treated receiving adipose-derived mesenchymal stem cells. Acute radiation-induced skin injury was induced by a single fraction of X-ray irradiation of 60Gy to a 3.0×3.0-cm area with a 1.3-cm bolus on 100-cm SSD in the abdominal skin tissue. Ultrasonic imaging of the depth and quality of healing in the skin tissue was performed by processing ultrasound images at 40-MHz and 75-MHz frequencies.
 Results: Skin thickness indicated a significant difference between the treatment and control groups on Day 10 after 60 Gy irradiation (P<0.05). The highest skin thickness was observed in the irradiated group, and the lowest skin thickness was found in the stem cell treatment group.
 Conclusion: Evaluation of skin thickness, wound depth, and scar formation is important for the proper assessment and management of wound healing in stem cell therapy of radiation-induced skin damage. High-resolution ultrasound at 40- and 75-MHz frequencies is a major non-invasive method providing unprecedented insight into determining the characterization of the skin, particularly in the context of wound healing.

Integrating Point-of-Care Bacterial Fluorescence Imaging-Guided Care with Continued Wound Measurement for Enhanced Wound Area Reduction Monitoring.

This prospective observational study investigated wound area reduction (WAR) outcomes in a complex wound population composed of non-healing acute and chronic wounds. The relationship between bacterial autofluorescence signals and WAR was investigated. Area measurements were collected both manually and digitally, and both methods were compared for accuracy. Twenty-six participants with 27 wounds of varying etiologies were observed twice weekly for two weeks. Digital wound measurement, wound bacterial status assessment, and targeted debridement were performed through a point-of-care fluorescence imaging device (MolecuLight® i: X, MolecuLight Inc, Toronto, Canada). The wound area reduction (WAR) rate was calculated using baseline and last visit measurements. Statistical analyses, including t-tests, Fisher exact tests, the Wilcoxon signed rank test for method comparison, and ANOVA for bacterial subgroups, were applied as pertinent. The overall average WAR was -3.80 cm2, or a decrease of 46.88% (manual measurement), and -2.62 cm2, or a 46.05% decrease (digital measurement via MolecuLight® device). There were no statistically significant differences between the WAR of acute and chronic wounds (p = 0.7877). A stepwise correlation between the WAR and bacterial status classification per fluorescence findings was observed, where persistent bacteria resulted in worse WAR outcomes. An overestimation of wound area by manual measurement was 23% on average. Fluorescence imaging signals were linked to WAR outcome and could be considered predictive. Wounds exhibiting bacterial loads that persisted at the end of the study period had worse WAR outcomes, while those for which management was able to effectively remove them demonstrated greater WAR. Manual measurement of the wound area consistently overestimated wound size when compared to digital measurement. However, if performed by the same operator, the overestimation was uniform enough that the WAR was calculated to be close to accurate. Notwithstanding, single wound measurements are likely to result in overestimation.

Features of Prontosan in the Complex Treatment of Purulent Wounds

Prontosan is intended for the treatment of acute and chronic wounds only when they require cleansing. Types of wounds that may be encountered include acute uninfected and infected wounds, such as traumatic wounds (skin lacerations, bites, cuts or crushes) and surgical wounds. The composition of the drug contains odorless gel, undecylenamidopropyl betaine, polyarninopropyl biguanide, glycerin, hydroxyethylcellulose and purified water. A pyrogen-free solution used for wound treatment that is sterile by aseptic processing until the product is first opened. Study of the features of the drug Prontosan in the treatment of purulent wounds. We performed laparoscopic adrenalectomies in 18 patients (14 — right-sided, 4 — left-sided), 4 patients underwent laparotomy and removal of the adrenal tumor due to large tumor sizes, one patient was unable to undergo adrenalectomy due to tumor growth into the inferior vena cava. The introduction of measures for the prevention and treatment of purulent-inflammatory complications contributed to improving the results of treatment of patients with purulent wounds. Implementation of the research results: the results of the work were implemented in the surgical departments of the Regional Clinical Hospital and the Regional Medical Clinical Hospital (measures to prevent complications with the use of the drug Prontosan). Prontosan allows for thorough cleansing of the wound surface, moisturizing the wound and suppressing bacterial flora, which creates conditions for rapid wound healing.

Long-term physical and psychological symptoms in Syrian men subjected to detention, conflict-related sexual violence and torture: cohort study of self-reported symptom evolution

Since March 2011, more than 1 million people, mostly men, have been arrested, detained, and tortured by the Assad regime. Published literature does not reflect the evolution of symptoms after male sexual and physical violence in detention. This cohort study examines the constellation and evolution of self-reported symptoms after male conflict-related sexual violence (CRSV) in Syrian state detention. Sexual, psychological, and physical symptoms and conditions experienced by a cohort of 106 male detainees after CRSV in Syrian regime detention were evaluated over a ten-year period (2012-2022). Men sought forensic medical expert evaluations (FMEs) to document torture and later consented to semi-structured interviews (SSIs), a median of 8.8 years after their detention. A standard data collection tool was used to assess symptoms and conditions during FMEs (Time 3), and at the time of the SSI (Time 4), during which men also reported symptoms experienced during detention (Time 1) and after detention release (Time 2). 30.2% of men spent more than 1 year in detention and 9.4% were detained >5 years. 90% reported being slapped, punched, kicked, hit with objects, 60.4% of men reported torture with multiple devices, and 48.1% reported being burned or electrocuted. Multiple sexual violence types were reported during detention: 97.2% forced nudity, 45.3% violence to genitals or anus, 30.2% collective sexual humiliation, and 9.4% rape. Men recalled nearly universal presence of acute pain, bleeding wounds, skin infections, sleep disturbances, fear, sadness, anxiety, and despair during detention. By Time 4, acute physical and psychological conditions were fading or absent, while scars, avoidance, intrusive memories, lack of trust, self-isolation, chronic pain, anger, and low self-esteem were reported by≥50%. The most persistently reported symptoms following detention through the SSI included scars, pain, intrusive memories, and avoidance in ≥50% of men. At the SSI, 26.4% of men reported erectile dysfunction and 23.6% challenges with sexual relations. Men reported persistent symptoms and conditions years after CRSV, torture and detention. The unique constellation of findings and their evolution in male CRSV survivors, particularly increasing rates of anger, distrust, and self-isolation, must urgently inform design and delivery of support services and health care. This study was funded by the United Kingdom Foreign Commonwealth and Development Office and the Arts and Humanities Research Council through the project 'Understanding and Addressing the Impact of Invisibility on Conflict-Related Male Sexual Violence in Syria'.

Extracellular Matrices as Bioactive Materials for In Situ Tissue Regeneration.

Bioactive materials based on a nature-derived extracellular matrix (NECM) represent a category of biomedical devices with versatile therapeutic applications in the realms of tissue repair and engineering. With advancements in decellularization technique, the inherent bioactive molecules and the innate nano-structural and mechanical properties are preserved in three-dimensional scaffolds mainly composed of collagens. Techniques such as electrospinning, three-dimensional printing, and the intricate fabrication of hydrogels are developed to mimic the physical structures, biosignalling and mechanical cues of ECM. Until now, there has been no approach that can fully account for the multifaceted properties and diverse applications of NECM. In this review, we introduce the main proteins composing NECMs and explicate the importance of them when used as therapeutic devices in tissue repair. Nano-structural features of NECM and their applications regarding tissue repair are summarized. The origins, degradability, and mechanical property of and immune responses to NECM are also introduced. Furthermore, we review their applications, and clinical features thereof, in the repair of acute and chronic wounds, abdominal hernia, breast deformity, etc. Some typical marketed devices based on NECM, their indications, and clinical relevance are summarized.

GehB Inactivates Lipoproteins to Delay the Healing of Acute Wounds Infected with Staphylococcus aureus.

Staphylococcus aureus is one of the most prevalent bacteria found in acute wounds. S. aureus produces many virulence factors and extracellular enzymes that contribute to bacterial survival, dissemination, and pathogenicity. Lipase GehB is a glycerol ester hydrolase that hydrolyzes triglycerides to facilitate the evasion of S. aureus from host immune recognition. However, the role and mechanism of lipase GehB in skin acute wound healing after S. aureus infection remain unclear. In this study, we found that the gehB gene deletion mutant (USA300ΔgehB) stimulated significantly higher levels of pro-inflammatory cytokines in RAW264.7 and Toll-like receptor 2 (TLR2)-transfected HEK293 cells than the wild-type USA300 strain did. Recombinant GehB-His treated lipoprotein (Lpp) reduced stimulation of TLR2-dependent TNF-α production by RAW264.7 macrophages. GehB delayed the skin acute wound healing in BALB/c mice infected with S. aureus, while wound healing was similar in C57BL/6 TLR2-/- mice infected with either wild-type USA300 or USA300ΔgehB. In BALB/c mice,we also observed more bacterial survival, less leukocyte recruitment, lower IL-8 production, and adipocyte differentiation in USA300-infected skin acute wound tissues than those in USA300ΔgehB-challenged ones. Our data indicated that GehB inactivates lipoproteins to shield S. aureus from innate immune killing, resulting in delayed the healing of skin acute wounds infected with S. aureus.

Chitosan nonwoven fabric composited calcium alginate and adenosine diphosphate as a hemostatic bandage for acute bleeding wounds

Acute bleeding following accidental injury is a leading cause of mortality. However, conventional hemostatic bandages impede wound healing by inducing excessive blood loss, dehydration, and adherence to granulation tissue. Strategies such as incorporating active hemostatic agents and implementing chemical modifications can augment the properties of these bandages. Nevertheless, the presence of remote thrombosis and initiators may pose risks to human health. Here, a hemostatic bandage was developed by physically combined chitosan nonwoven fabric, calcium alginate sponge, and adenosine diphosphate. The presented hemostatic bandage not only exhibits active and passive mechanisms for promoting clotting but also demonstrates excellent mechanical properties, breathability, ease of removal without causing damage to the wound bed or surrounding tissues, as well as maintaining an optimal moist environment conducive to wound healing. In vitro evaluation results indicated that the hemostatic bandage possesses favorable cytocompatibility with low levels of hemolysis. Furthermore, it effectively aggregates various blood cells while activating platelets synergistically to promote both extrinsic and intrinsic coagulation pathways. In an in vivo rat model study involving liver laceration and femoral artery injury scenarios, our developed hemostatic bandage demonstrated rapid clot formation capabilities along with reduced blood loss compared to commercially available fabrics.

Wound healing efficacy of a polymeric spray film solution containing Centella asiatica leaf extract on acute wounds

Objective: To study the clinical efficacy of a polymeric spray film containing Centella asiatica extract to heal acute wounds. Method: A polymeric spray film solution for wound healing was formulated using Centella asiatica extract, which contained triterpenes, including asiatic acid, madecassic acid, asiaticoside and madecassoside. The stability and physicochemical properties of the formulation were evaluated, and a multicentre, randomised, controlled trial was conducted to assess its clinical wound-healing efficacy. The Pressure Ulcer Scale for Healing (PUSH Tool) score was used to evaluate wound healing on days 0, 3, 5 and 7. Results: The cohort consisted of 60 volunteers with clean-contaminated wounds (class 1), randomly assigned to the Control (n=30) and Testing (n=30) groups. The spray product contained asiatic acid, madecassic acid, asiaticoside and madecassoside at 0.20±0.02mg/ml, 0.16±0.01mg/ml, 0.32±0.03mg/ml and 0.10±0.00mg/ml, respectively. The pH value was 5.5±0.01, and the viscosity was 33±4cP. The product was stable for six months when stored at 30±2°C and at 40±2°C, in 75±5% relative humidity. The tested product significantly reduced the total PUSH and exudate scores, indicating that the polymeric spray film solution containing Centella asiatica improved wound healing. The average healing recovery times for the Testing and Control groups were 4.6±1.1 days and 4.87±1.0 days, respectively. Conclusion: In this study, Centella asiatica extract-containing polymeric spray film solution was beneficial as an acute wound medication, which could shorten healing time with no adverse effects.

Pleiotropic effects of hyaluronic acid and silver sulfadiazine dressings in the treatment of acute and chronic skin lesions.

Hyaluronic acid (HA) is a natural unbranched polymer that belongs to a group of heteropolysaccharide glycosaminoglycans (GAGs) that are major components of the extracellular matrix (ECM), while silver sulfadiazine exerts antibacterial activity. In this study, we evaluated the efficacy and safety of dressings with hyaluronic acid and silver sulfadiazine in acute and chronic lesions, according to the wound bed preparation and TIME principles. Thirty-two patients with acute and chronic injuries participated in the study. After collecting their personal histories and making a differential diagnosis by evaluating their ankle/arm index, patients with a Winsor Index below 0.8 underwent lower extremity color Doppler echocardiography. The dressing protocol followed the principles of wound bed preparation, identifying the prevailing clinical sign by evaluating the lesion background, margins, and perilesional skin. A product containing low molecular weight hyaluronic acid (200 kDa) and silver sulfadiazine 1% was used for the dressing. In the acute lesion group, the protocol we applied resulted in all injuries being healed. Of the 20 treated wounds in the chronic lesion group, 10 healed at the end of 8 weeks of treatment and 8 saw an improvement with a reduction in the lesion area. Consisting of a combination of hyaluronic acid and silver sulfadiazine, the dressing is widely used in the management of acute and chronic skin wounds. In the present study, the healing rate of acute wounds was 100%; in chronic wounds, healing was reported in 50% of cases while in 40% of the remainder, we found a 40% reduction in the lesion area.

561. Microbial Analysis and Fungi-Bacteria Correlation in Chronic Wound Infection Patients

Abstract Background Chronic wound infection has become a major healthcare burden globally. The colonized microbiome features and correlation between bacteria and fungi have not been listed. Methods In this study, we enrolled 38 acute wound infection and 28 chronic wound infection patients. The wound swabs sampling at admission were tested by metagenomic next-generation sequencing. Microbial community characteristics in wound infection patients and bacteria-fungi correlations in chronic wound infection patients were analyse after filtering background organisms.Figure 1.Flow chart Results We found that wound microbiome in chronic wound infection patients had higher abundance of Pseudomonas aeruginosa than that in acute wound patients. Meanwhile, microbes with high relative abundant in chronic infection wounds were less significantly association with plasma inflammation factors compared with those in acute infection wounds. Finally, we investigated the association between fungi and bacteria in chronic infection patients and found that relative abundance of Pseudomonas aeruginosa was negatively associated with that of Candida albicans.Figure 2.Comparison of bacteria species relative abundance between groups.Barplot of average relative frequencies of genera. Only genera>1% of relative abundance in wound were represented. C= chronic infection wound group, NC= acute infection wound groupFigure 3.Analysis of Linear Discriminant Analysis (LDA) Effect Size in groups.The bar graph showed pathogens with LDA score log10 >5 in two groups. C= chronic infection wound group, NC= acute infection wound group.Figure 4.Fungi-bacteria network in patients with chronic infection wound.Green dots: bacteria; Blue dots: fungi; red edge: positive correlation; green edge: negative correlation. Relative abundance of Pseudomonas aeruginosa was negatively associated with that of Candida albicans highlighted with red box. Conclusion Our metagenomic sequencing results of wound supported that Pseudomonas aeruginosa may be the biomarker of chronic wound infection and have interaction with candida albicans. Disclosures All Authors: No reported disclosures

Exploring lived experiences of gunshot wound survivors: A key to ethnographically informed public health interventions for curbing firearm violence

IntroThe high rates of gun violence in the United States are a recognized public health concern with increased attention since the 1990′s. The predominant studies used in gun violence research have been epidemiological approaches and quantitative analyses. This study, instead, examines lived experiences of gunshot wound survivors to better understand their situations. This study also compared the different census categories and their types of gunshot wound injuries. Ethnographic informed analyses may inform public health interventions to decrease firearm injuries. MethodsData was collected through a series of semi-structured interviews at the emergency department of an urban, Level-1, academic trauma center. 96 patients with gunshot wounds (GSWs) from 2018–2022 were included in the study. Thematic analysis was conducted after coding interview responses. ResultsThere was a significant difference found between the 2 census categories (White and Minority populations). Those who self-identified as white had more self-inflicted GSWs (6) than other groups. Those who self-identified in the minority population had more GSWs as a result of an altercation (36) or as an innocent bystander (20). Interview data also demonstrated a trend in changing opinions about firearms in a group of participants with remote previous gunshot wounds (pGSW). When compared to the acute gunshot wound group (aGSW) the previous gunshot wound group (pGSW) responses showed support for increased gun safety and policies that limit firearm access. ConclusionDifferent injury patterns between census groups demonstrates that multiple public health approaches will be needed to decrease firearm violence. Ethnographically informed approaches, including the support of people with previous GSW injuries, may help craft those interventions to reduce injury. Matched peer support programs represent one potential intervention to decrease secondary injury and firearm violence.

PH-responsive double-enzyme active metal–organic framework for promoting the healing of infected wounds

The abuse of antibiotics accelerates the spread and evolution of drug-resistant bacteria, which seriously threatens human health. Hydroxyl radicals (•OH) are generated by peroxidase in the presence of H2O2, which is strongly oxidizing and can effectively kill bacteria. However, high production costs and poor stability limit the clinical use of natural enzymes. “Nanozyme” is a general term for nanomaterials with catalytic activity similar to that of biological enzymes. Compared to biological enzymes, nanozymes have the advantages of low cost, facile preparation, and easy storage, making them a good choice for the development of antibacterial agents. Here, a nickel-based metal–organic framework (Ni-MOF) with dual enzymatic activity that switches depending on the pH environment was studied. In a slightly acidic environment, Ni-MOF can react with hydrogen peroxide to produce hydroxyl radicals that kill bacteria; in a neutral environment, Ni-MOF instead removes excessive reactive oxygen species (ROS) and promotes the transformation of macrophages into M2 macrophages. Compared to most nanozymes, Ni-MOF has unique electrical conductivity and better biosafety. The results of animal experiments show that Ni-MOF can not only treat infected wounds but also promote the healing of acute wounds and exhibits great clinical application potential.

A Programmable Oxygenation Device Facilitates Oxygen Generation and Replenishment to Promote Wound Healing.

Inadequate oxygenation is one of the chief culprits for delayed wound healing. However, current oxygen therapies, such as hyperbaric oxygen therapy and topical oxygen therapy, face hurdles in providing sustained and long-term oxygenation to reverse wound hypoxia. Furthermore, their efficacy in rejuvenating wound injury is restricted by limited penetration of oxygen in the wound bed. Herein, this study proposes a programmable and portable oxygenation device (named GUFO oxydevice) by ingeniously integrating i) a controllable oxygen generation and unidirectional transmission system (COGT-UTS), and ii) a supramolecular assembled perfluorinated hyperbranched polymer/gelatin (GUF) hydrogel in which the perfluorinated hyperbranched polymer (FHBP) acts as an oxygen reservoir to ensure sustained and convenient oxygen replenishment and thus directly regulate the hypoxic wound microenvironment. Accelerating the wound healing process by GUFO oxydeviceis achieved in both a diabetic rat and an acute porcine wound model without any secondary tissue damages. The present study demonstrates that the GUFO oxydevice holds promise as a practically feasible candidate for wound treatment.

Biocompatible Rhamnolipid Self-Assemblies with pH-Responsive Antimicrobial Activity.

There is an urgent need for alternative antimicrobial materials due to the growing challenge of bacteria becoming resistant to conventional antibiotics. This study demonstrates the creation of a biocompatible pH-switchable antimicrobial material by combining bacteria-derived rhamnolipids (RL) and food-grade glycerol monooleate (GMO). The integration of RL into dispersed GMO particles, with an inverse-type liquid crystalline cubic structure in the core, leads to colloidally stable supramolecular materials. The composition and pH-triggered structural transformations are studied with small-angle X-ray scattering, cryogenic transmission electron microscopy, and dynamic light scattering. The composition-structure-activity relationship is analyzed and optimized to target bacteria at acidic pH values of acute wounds. The new RL/GMO dispersions reduce Staphylococcus aureus (S. aureus) populations by 7-log after 24h of treatment with 64µg mL-1 of RL and prevent biofilm formation at pH = 5.0, but have no activity at pH = 7.0. Additionally, the system is active against methicillin-resistant S. aureus (MRSA) with minimum inhibitory concentration of 128µg mL-1 at pH 5.0. No activity is found against several Gram-negative bacteria at pH 5.0 and 7.0. The results provide a fundamental understanding of lipid self-assembly and the design of lipid-based biomaterials, which can further guide the development of alternative bio-based solutions to combat bacteria.

Facile strategy for gelatin-based hydrogel with multifunctionalities to remodel wound microenvironment and accelerate healing of acute and diabetic wounds

Chronic diabetic wounds represent the most common diabetes complication. Wound healing depends on scavenging reactive oxygen species (ROS), neovascularization, and controlling infection. A naturally derived gelatin-based hydrogel is biocompatible, biodegradable, does not promote inflammation, and can remove ROS, but strategies for developing a gelatin-based hydrogel currently require careful chemical modification of gelatin and time-consuming purification and post-crosslinking processing. Herein, a facile method of combining zirconium (Zr4+), gelatin, and quercetin (QCN) to generate an injectable gelatin-based hydrogel (QCN@Gel-Zr) for diabetic wound treatment was presented. Adding QCN improved the mechanical, injection, and adhesive performance of the Gel-Zr hydrogel and conferred antibacterial and free radical–scavenging abilities. These properties induced cellular proliferation and migration, protection against oxidative stress, and reduction in inflammatory expression. In vivo models of acute and chronic diabetic skin wounds were used to demonstrate biocompatibility and the ability of the gelatin hydrogels to promote wound healing. The histological analysis showed that the QCN@Gel–Zr hydrogel promoted angiogenesis, collagen deposition, and hair follicle regeneration with no detectable cytotoxicity. This study demonstrates the preparation of gelatin-based hydrogel with various flexible functions to address the complex biological requirements of diabetic wound repair.

Copper Nanodots-Based Hybrid Hydrogels with Multiple Enzyme Activities for Acute and Infected Wound Repair.

Effectively controlling bacterial infection, reducing the inflammation and promoting vascular regeneration are all essential strategies for wound repair. Nanozyme technology has potential applications in the treatment of infections because its non-antibiotic dependent, topical and noninvasive nature. In wound management, copper-based nanozymes have emerged as viable alternatives to antibiotics. In this study, an ultrasmall cupric enzyme with high enzymatic activity is synthesized and added to a nontoxic, self-healing, injectable cationic guar gum (CG) hydrogel network. The nanozyme exhibits remarkable antioxidant properties under neutral conditions, effectively scavenging reactive nitrogen and oxygen species (RNOS). Under acidic conditions, Cu NDs have peroxide (POD) enzyme-like activity, which allows them to eliminate hydrogen peroxides and produce free radicals locally. Antibacterial experiments show that they can kill bacteria and remove biofilms. It reveals that low concentrations of Cu ND/CG decrease the expression of the inflammatory factors in cells and tissues, effectively controlling inflammatory responses. Cu ND/CG hydrogels also inhibit HIF-1α and promote VEGF expression in the wound with the ability to promote vascular regeneration. In vivo safety assessments reveal a favorable biosafety profile. Cu ND/CG hydrogels offer a promising solution for treating acute and infected wounds, highlighting the potential ofinnovative nanomaterials in wound healing.