Hydrogen Peroxide: A Potential Wound Therapeutic Target?

Hydrogen peroxide irrigation as an adjunct to digital rectal examination for detection of penetrating low rectal injuries

Background

Rectal trauma carries significant morbidity, particularly if there is a delay in diagnosis. Digital rectal examination has a relatively low sensitivity. Proctoscopy and sigmoidoscopy are available but can be limited in situations with increased fecal burden or uncooperative patients. We suggest more sensitive bedside techniques are necessary to diagnose low rectal injury, and here present a case report to demonstrate proof of concept using hydrogen peroxide to directly visualize an injury.

Methods

Digital rectal examination was performed in a patient after multiple gunshot wounds and was negative for gross blood. Suspicion for low rectal injury remained high, and hydrogen peroxide was used to evaluate bullet trajectory. Approximately 25 mL of 3% hydrogen peroxide was instilled into the bullet tract.

Results

Hydrogen peroxide evaluation of the bullet tract was performed in less than 1 min with minimal supplies and preparation. It revealed an extraperitoneal injury where the rectal examination had been falsely negative.

Conclusion

Hydrogen peroxide may be used to evaluate a suspected penetrating injury of the rectum. Considering the potential of this modality to diagnose injuries in a timely and reliable manner, additional investigation may be warranted.

Antibacterial sponge for rapid noncompressible hemostatic treatment: spatiotemporal studies using a noninvasive model

Hemorrhage is one of the leading causes of preventable death. While minor injuries can be treated mainly by conventional methods, deep and irregular wounds with profuse bleeding present significant challenges, some of which can be life-threatening and fatal. This underscores the need to develop easily applicable FDA-approved hemostatic treatments that can effectively stanch blood loss at the point of care before professional medical care. A silicone-based bandage system (SilFoam), a non-compressible, self-expanding, antibacterial hemostatic treatment, is reported here. Its two-component system reacts in situ upon mixing to form a stretchable sponge that acts as a 'tamponade' by expanding within seconds with the evolution of oxygen gas from the interaction of the reactive components present in the formulation. This generates autogenous pressure on the wound that can effectively arrest heavy bleeding within minutes. Possessing optimal adhesive properties, the expanded sponge can be easily removed, rendering it optimal for hemostatic wound dressing. With recent advances in biotechnological research, there is a growing awareness of the potential issues associated with in vivo trials, spanning ethical, psychological, economic, and physiological concerns like burnout and fatigue. Bearing this in mind, a unique manikin system simulating a deep abdominal wound has been employed to investigate SilFoam's hemostatic efficacy with different blood-flow rates using a non-invasive model that aims to provide an easy, fast, and economical route to test hemostatic treatments before in vivo studies. This is the first time an Ag2O-based oxygen-induced foaming system has been reported as a hemostatic agent.

Nanozyme-Incorporated Microneedles for the Treatment of Chronic Wounds

Acute wounds are converted to chronic wounds due to advanced age and diabetic complications. Nanozymes catalyze ROS production to kill bacteria without causing drug resistance, while microneedles (MNs) can break through the skin barrier to deliver drugs effectively. Nanozymes can be intergrateded into MNs delivery systems to improve painless drug delivery. It can also reduce the effective dose of drug sterilization while increasing delivery efficiency and effectively killing wounded bacteria while preventing drug resistance. This paper describes various types of metal nanozymes from previous studies and compares their mutual enhancement with nanozymes. The pooled results show that the MNs, through material innovation, are able to both penetrate the scab and deliver nanozymes and exert additional anti-inflammatory and bactericidal effects. The catalytic effect of some of the nanozymes can also accelerate the lysis of the MNs or create a cascade reaction against inflammation and infection. However, the issue of increased toxicity associated with skin penetration and clinical translation remains a challenge. This study reviews the latest published results and corresponding challenges associated with the use of MNs combined with nanozymes for the treatment of wounds, providing further information for future research.

A hydrogel based on Fe(II)-GMP demonstrates tunable emission, self-healing mechanical strength and Fenton chemistry-mediated notable antibacterial properties

Supramolecular hydrogels serve as an excellent platform to enable in situ reactive oxygen species (ROS) generation while maintaining controlled localized conditions, thereby mitigating cytotoxicity. Herein, we demonstrate hydrogel formation using guanosine-5'-monophosphate (GMP) with tetra(4-carboxylphenyl) ethylene (1) to exhibit aggregation-induced emission (AIE) and tunable mechanical strength in the presence of divalent metal ions such as Ca2+, Mg2+, and Fe2+. The addition of divalent metal ions leads to structural transformation in the metallogels (M-1GMP). Furthermore, the incorporation of Fe2+ ions into the hydrogel (Fe-1GMP) promotes the Fenton reaction that could be upregulated upon adding ascorbic acid (AA), demonstrating antibacterial efficacy via ROS generation. In vitro studies on AA-loaded Fe-1GMP demonstrate excellent bacterial killing efficacy against E. coli, S. aureus and vancomycin-resistant enterococci (VRE) strains. Finally, in vivo studies involving topical administration of Fe-1GMP to Balb/c mice with skin infections further suggest the potential antibacterial efficacy of the hydrogel. Taken together, the hydrogel with its unique combination of mechanical tunability, ROS generation capability and antibacterial efficacy can be used for biomedical applications, particularly in wound healing and infection control.

Management of an elderly patient with retention of a steel nail in the scrotum: a case report

BACKGROUND

The retention of foreign bodies inside the body during ludic/sexual procedures or for traumatism represents one of the causes of visits to accident and emergency departments that often requires surgical removal of the foreign body. However, there are cases where the discovery of such foreign bodies takes place after many years, as in patients that are slightly compromised from a neuro-sociological point of view.

CASE PRESENTATION

A 76-year-old male presented to an outpatient urological examination due to an increase in scrotal volume. At the ultrasound check, an acoustic interference from a solid object was detected, for which computed tomography was requested. The computed tomography scan revealed the presence of an elongated metal body in the perineum. The removal of the foreign body in the operating theatre was then scheduled. A 10 cm long stainless-steel nail located within an abscessed foreign body granuloma was identified and removed via a scrotal access. Four days later, a new surgical toilet was performed due to minimal necrosis of the skin flaps. The patient then performed three more dressings in the operating theatre during the following week. Healing took place by secondary intention until a perfect healing of the surgical wound was obtained.

CONCLUSIONS

Removal of foreign bodies from the perineum in case of infection can be challenging. Careful attention and postoperative dressings are crucial for the success of the case.

Ultrasound-Mediated Antibiotic Delivery to In Vivo Biofilm Infections: A Review

Bacterial biofilms are a significant concern in various medical contexts due to their resilience to our immune system as well as antibiotic therapy. Biofilms often require surgical removal and frequently lead to recurrent or chronic infections. Therefore, there is an urgent need for improved strategies to treat biofilm infections. Ultrasound-mediated drug delivery is a technique that combines ultrasound application, often with the administration of acoustically-active agents, to enhance drug delivery to specific target tissues or cells within the body. This method involves using ultrasound waves to assist in the transportation or activation of medications, improving their penetration, distribution, and efficacy at the desired site. The advantages of ultrasound-mediated drug delivery include targeted and localized delivery, reduced systemic side effects, and improved efficacy of the drug at lower doses. This review scrutinizes recent advances in the application of ultrasound-mediated drug delivery for treating biofilm infections, focusing on in vivo studies. We examine the strengths and limitations of this technology in the context of wound infections, device-associated infections, lung infections and abscesses, and discuss current gaps in knowledge and clinical translation considerations.

A evidence-based approach to selecting post-exercise cryostimulation techniques for improving exercise performance and fatigue recovery: A systematic review and meta-analysis

Rationale

Cryostimulation involves using water environments and low temperatures as intervention mediums, with main methods including CWI (cold water immersion), CWT (contrast water therapy), and WBC (whole-body cryostimulation). Previous systematic reviews focused on the effect of cryostimulation on muscle fatigue and sports performance. However, studies on the selection of different cryostimulation methods and their intervention effects present inconsistent results.

Introduction

To systematically review and methodologically appraise the quality and effectiveness of existing intervention studies that the effects of various cryostimulation methods, including CWI, CWT, and WBC, on exercise performance and fatigue recovery.

Methods

Following PRISMA guidelines, we conducted searches in PubMed, Embase, The Cochrane Library, Web of Science, and EBSCO databases to gather randomized controlled trials or self-controlled trials involving CWI/CWT/WBC and their effects on exercise performance or fatigue recovery. The search period ranged from November 2013 to November 2, 2023. Literature screening was performed using EndNote X9.1, and the quality of included studies was assessed using the Cochrane risk of bias assessment tool. Meta-analysis was conducted using RevMan 5.3 software.

Results

This study included a total of 18 articles, included a total of 499 healthy participants, comprising 479 males and 20 females. Among them, participants underwent cryostimulation, including 102 using CWT, using CWI, and 58 using WBC. Compared to the control group, cryostimulation can significantly alleviate muscle pain intensity (SMD -0.45, 95% CL -0.82 to 0.09, P = 0.01). Specifically, CWI significantly reduced muscle pain intensity (SMD = -0.45, 95% CI: 0.820.09, P = 0.01), WBC significantly decreased C-reactive protein levels (SMD = -1.36, 95% CI: 2.350.36, P = 0.008). While, CWT showed no significant differences from the control group in exercise performance and fatigue recovery indicators (P > 0.05).

Conclusion

Cryostimulation can significantly reduce muscle pain intensity and perceived fatigue. Specifically, CWI significantly alleviates muscle pain intensity, WBC significantly lowers markers of inflammation caused by fatigue after exercise, in contrast, CWT does not significantly improve exercise performance and fatigue recovery. After exercise, compared with rest, using cryostimulation may have more noticeable benefits for muscle fatigue and muscle pain, with recommendations prioritizing WBC and CWI particularly for addressing inflammation and muscle pain. However, all cryostimulation may have no significant influence on exercise performance.

[Antiseptics in otorhinolaryngology-a substance overview]

For preoperative skin antisepsis, alcohol-containing iodine solutions and octenidine are suitable. For wound antisepsis, polyhexanide and hypochlorous acid (HOCL) are also available, but only PVP-iodine and HOCL can be applied to cartilage. Chlorhexidine should only be used as mouth- and bodywash for Staphylococcus aureus (MRSA) decolonization. For the many other throat antiseptics, evidence of clinical efficacy is lacking. For decolonization of the nares, polyhexanide and octenidine are available as nasal gels, but these are inferior to mupirocin for MRSA decolonization. PVP-iodine and HOCL are safe to use for nasal irrigation, but only HOCL has proven effective to improve symptoms of chronic rhinosinusitis. All antiseptics exhibit a certain ototoxicity. With an intact eardrum, acetic acid-containing eardrops can be used to prevent and treat external otitis and myringitis. When the eardrum is perforated, only alcohol-free PVP-iodine and HOCL may be used.

Studies on bioactivities of Manuka and regional varieties of honey for their potential use as natural antibiotic agents for infection control related to wound healing and in pharmaceutical formulations

Presently, most of the reported infections are of a bacterial origin; however, this leads to a limit within the literature and research around infections caused by fungal pathogens, which are now developing resistance to antibiotic medicines. Of the natural antimicrobial agents, honey has been observed with demonstrable and highly exploitable antimicrobial and infection control related to wound healing properties; therefore, it has been incorporated into many standard pharmaceutical formulations. Generally, these products utilize a pure sample of honey as a bioactive ingredient in a product which has been purposely designed for the convenience of application. This article aims to review information available from published reports on various bioactivities of a variety of medical-grade honey products, including manuka and other conventional non-manuka types sourced from different floral types and geographical regions. Additionally, this review highlights the antibiotic activities of various types of honey products tested against pathogenic strains of bacteria, yeast and fungi, and their applications in the formulation of healthcare products.

Au nanozyme-based multifunctional hydrogel for inflammation visible monitoring and treatment

Chronic inflammation can delay wound healing, eventually leading to tissue necrosis and even cancer. Developing real-time intelligent inflammation monitoring and treatment to achieve effective wound management is important to promote wound healing. In this study, a smart multifunctional hydrogel (Hydrogel@Au NCs&DG) was proposed to monitor and treat the wound inflammation. It was prepared by mixing 3-carboxy-phenylboronic acid modified chitosan (CS-cPBA), β-glycerophosphate (β-GP), albumin-protected gold nanoclusters (BSA-Au NCs), and dipotassium glycyrrhizinate (DG) about 10 s. In this hydrogel, CS-cPBA and β-GP are crosslinked together by boric acid ester bond and hydrogen bond to form the main hydrogel network, endowing the hydrogel with self-healing and injectable properties to adapt irregular wounds. Importantly, the as-prepared hydrogel with good biocompatibility and excellent adhesion property could directly determine the H2O2 to monitor the wound microenvironment by visible fluorescence change of BSA-Au NCs and then guide the frequency of dressing change to eliminate inflammation. The results demonstrated that the as-prepared smart hydrogel could be expected to serve as an intelligent wound dressing to promote inflammation-infected wound healing.

DUAL ACTION ELECTROCHEMICAL BANDAGE OPERATED by a PROGRAMMABLE MULTIMODAL WEARABLE POTENTIOSTAT

Electrochemical bandages (e-bandages) can be applied to biofilm-infected wounds to generate reactive oxygen species, such as hypochlorous acid (HOCl) or hydrogen peroxide (H 2 O 2 ). The e-bandage-generated HOCl or H 2 O 2 kills biofilms in vitro and in infected wounds on mice. The HOCl-generating e-bandage is more active against biofilms in vitro , although this distinction is less apparent in vivo . The H 2 O 2 -generating e-bandage, more than the HOCl-generating e-bandage, is associated with improved healing of infected wounds. A strategy in which H 2 O 2 and HOCl are generated alternately-for dual action-was explored. The goal was to develop a programmable multimodal wearable potentiostat (PMWP) that could be programmed to generate HOCl or H 2 O 2 , as needed. An ultralow-power microcontroller unit managed operation of the PMWP. The system was operated with a 260-mAh capacity coin battery and weighed 4.6 grams, making it suitable for small animal experiments or human use. The overall cost of a single wearable potentiostat was $6.50 (USD). The device was verified using established electrochemical systems and functioned comparably to a commercial potentiostat. To determine antimicrobial effectiveness, PMWP-controlled e-bandages were tested against clinical isolates of four prevalent chronic wound bacterial pathogens, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Acinetobacter baumannii , and Enterococcus faecium , and one fungal pathogen of emerging concern, Candida auris . PMWP-controlled e-bandages exhibited broad-spectrum activity against biofilms of all study isolates tested when programmed to deliver HOCl followed by H 2 O 2 . These results show that the PMWP operates effectively and is suitable for animal testing.

Navigating Treatment Dilemmas: Recalcitrant Pemphigus and the Burden of Multiple Comorbidities

Pemphigus vulgaris is a chronic autoimmune disease of the skin caused by the production of autoantibodies targeting desmogleins 1 and 3 usually presenting in individuals with an average age of onset of approximately 40 years. A 35-year-old obese, diabetic woman presented with fluid-filled lesions over her body for three months along with erosions and painful ulcers in her mouth and genital area for two months. Based on clinical and histopathological studies, the patient was diagnosed as a case of pemphigus vulgaris. She was started on conventional treatment with oral corticosteroids followed by pulse therapy and mycophenolate mofetil. Rituximab infusion was scheduled but could not be administered due to elevated D-dimer values. The patient underwent screening for deep vein thrombosis (DVT) and received subcutaneous enoxaparin and oral rivaroxaban. She developed severe sepsis for which she was treated with systemic antibiotics. She subsequently developed acute renal failure and underwent hemodialysis. The patient's clinical condition further deteriorated, which necessitated therapeutic plasma exchange (TPE). Collagen, colloidal silver, and silicone foam dressings were done to hasten wound healing. Two distinct approaches were employed to eliminate the pseudomembrane on the wounds. One portion was treated with hydrogen peroxide (H2O2), while the other was with hyaluronidase. The hyaluronidase treatment resulted in considerable improvement of the lesions. Intravenous immunoglobulin (IVIG) infusion was scheduled. However, the treatment could not be administered as the patient succumbed to death due to pulmonary thromboembolism (PTE) secondary to DVT.

Nanozyme-Engineered Hydrogels for Anti-Inflammation and Skin Regeneration

Inflammatory skin disorders can cause chronic scarring and functional impairments, posing a significant burden on patients and the healthcare system. Conventional therapies, such as corticosteroids and nonsteroidal anti-inflammatory drugs, are limited in efficacy and associated with adverse effects. Recently, nanozyme (NZ)-based hydrogels have shown great promise in addressing these challenges. NZ-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of hydrogels. The multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and differentiation. This review highlights the current state of the art in NZ-engineered hydrogels (NZ@hydrogels) for anti-inflammatory and skin regeneration applications. It also discusses the underlying chemo-mechano-biological mechanisms behind their effectiveness. Additionally, the challenges and future directions in this ground, particularly their clinical translation, are addressed. The insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels, offering new possibilities for targeted and personalized skin-care therapies.

A multimodal therapy for infected diabetic wounds based on glucose-responsive nanocomposite-integrated microneedles

Diabetic wounds in a state of high glucose are refractory to treatment and healing, especially if they are infected with bacteria. Herein, a novel nanocomposite (CIP/GOx@ZIF-8) was synthesized by loading ciprofloxacin hydrochloride (CIP) and glucose oxidase (GOx) into zeolitic imidazole framework-8 (ZIF-8) that exhibited good glucose sensitivity and catalytic activity. The high glucose in diabetic wounds could be decomposed into hydrogen peroxide (H2O2) and gluconic acid via the catalysis of GOx, which further destroyed CIP/GOx@ZIF-8 to release Zn2+ and cargos. The combination of glucose starvation, Zn2+, H2O2 and CIP could elevate the antibacterial effect and reduce bacterial resistance. Subsequently, the nanocomposite was fabricated into dissolving microneedles (CIP/GOx@ZIF-8 MNs) using polyvinylpyrrolidone (PVP). The microneedles exhibited good mechanical strength, puncture performance, dissolving performance, glucose responsiveness, antibacterial performance and biocompatibility. For in vivo wound healing, CIP/GOx@ZIF-8 MNs with good biosafety facilitated neovascularization and collagen deposition as well as reduced inflammation, and the wounds were almost healed after treatment. This multimodal therapeutic strategy is created to provide a unique treatment for infected diabetic wounds.

An oxygen-releasing agent promotes healing of skin wounds in rats

OBJECTIVE

To evaluate the local effect of a slow oxygen-release gel on the healing of standardised skin wounds caused in rats.

METHOD

Skin wounds were created on the backs of male rats (Rattus norvegicus, Wistar) that were randomly allocated into two groups. In the treated (T) and control (C) groups, oxygen gel and distilled water, respectively, were applied to the wounds on alternate days for 28 days. Postoperatively, euthanasia was performed at 5, 10, 14, 21 and 28 days, followed by clinical, histological (Masson's trichrome) and immunohistochemical analysis. Data were subjected to analysis of variance (ANOVA) and Bonferroni's test.

RESULTS

The cohort comprised 50 rats. On clinical and histological analysis, groups C and T showed similar characteristics 5 days post-operation. Subsequently, group T showed better healing at 14, 21 and 28 days and presented more intense inflammatory infiltrate up to 10 days. At days 14, 21 and 28, group T exhibited a reduction in oedema and increased angiogenesis, granulation tissue formation, and deposition of collagen fibres than group C. Immunohistochemical analysis showed the presence of tumour necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) in both the groups, but the levels were significantly higher in group T (p<0.05).

CONCLUSION

The local application of slow oxygen-release gel accelerated the healing of standardised skin wounds created surgically in rats, with increased angiogenesis and better collagen fibre formation.

Characterisation of physicochemical parameters and antibacterial properties of New Caledonian honeys

Honey is an attractive natural product with various health benefits. A few honey-based commercial products have successfully been adopted in clinics to improve wound healing. However, screening of other potential sources of medical-grade honey, in particular, honeys from territories with high floral species diversity and high endemicity, is highly needed. The goal of this study was to characterise the physicochemical and antibacterial properties of New Caledonian honey samples (n = 33) and to elucidate the major mechanism of their antibacterial action. Inhibitory antibacterial activity of honeys against Staphylococcus aureus and Pseudomonas aeruginosa was determined with a minimum inhibitory concentration (MIC) assay. Enzymatic activity of glucose oxidase and the content of hydrogen peroxide (H2O2) in honey samples were analysed. Furthermore, total protein content of honeys together with their electrophoretic protein profiles were also determined in the study. The antibacterial efficacy of 24% of the tested honey samples was slightly superior to that of manuka honey with unique manuka factor 15+. The antibacterial activity of catalase-treated honey sample solutions was significantly reduced, suggesting that H2O2 is a key antibacterial compound of diluted honeys. However, the kinetic profiles of H2O2 production in most potent honeys at a MIC value of 6% was not uniform. Under the experimental conditions, we found that a H2O2 concentration of 150 μM in diluted honeys is a critical concentration for inhibiting the growth of S. aureus. In contrast, 150 μM H2O2 in artificial honey solution was not able to inhibit bacterial growth, suggesting a role of phytochemicals in the antibacterial activity of natural honey. In addition, the continuous generation of H2O2 in diluted honey demonstrated an ability to counteract additional bacteria in re-inoculation experiments. In conclusion, the tested New Caledonian honey samples showed strong antibacterial activity, primarily based on H2O2 action, and therefore represent a suitable source for medical-grade honey.

Glucose-Responsive Fibrin Hydrogel-Based Multimodal Nucleic Acid Delivery System

Nucleic acid therapy has emerged as a potential alternative for promoting wound healing by gene expression modification. On the other hand, protecting the nucleic acid payload from degradation, efficient bioresponsive delivery and effective transfection into cells remain challenging. A glucose-responsive gene delivery system for treating diabetic wounds would be advantageous as it would be responsive to the underlying pathology giving a regulated payload delivery with fewer side effects. Herein a GOx-based glucose-responsive delivery system is designed based on fibrin-coated polymeric microcapsules (FCPMC) using the layer-by-layer (LbL) approach that simultaneously delivers two nucleic acids in diabetic wounds. The designed FCPMC displays an ability to effectively load many nucleic acids in polyplexes and release it over a prolonged period with no cytotoxic effects seen in in vitro studies. Furthermore, the developed system does not show any undesired effects in vivo. When applied to wounds in genetically diabetic db/db mice, the fabricated system on its own improves reepithelialization and angiogenesis while decreasing inflammation. Also, key proteins involved in the wound healing process, i.e., Actn2, MYBPC1, and desmin, are upregulated in the glucose-responsive fibrin hydrogel (GRFHG) treated group of animals. In conclusion, the fabricated hydrogel promotes wound healing. Furthermore, the system may be encapsulated with various therapeutic nucleic acids that aid wound healing.

Reactive Oxygen Species: A Crosslink between Plant and Human Eukaryotic Cell Systems

Reactive oxygen species (ROS) are important regulating factors that play a dual role in plant and human cells. As the first messenger response in organisms, ROS coordinate signals in growth, development, and metabolic activity pathways. They also can act as an alarm mechanism, triggering cellular responses to harmful stimuli. However, excess ROS cause oxidative stress-related damage and oxidize organic substances, leading to cellular malfunctions. This review summarizes the current research status and mechanisms of ROS in plant and human eukaryotic cells, highlighting the differences and similarities between the two and elucidating their interactions with other reactive substances and ROS. Based on the similar regulatory and metabolic ROS pathways in the two kingdoms, this review proposes future developments that can provide opportunities to develop novel strategies for treating human diseases or creating greater agricultural value.

Alkaline hydrogen peroxide solutions: expectorant, pyolytic, mucolytic, haemolytic, oxygen-releasing, and decolorizing effects

The local action of hydrogen peroxide solutions on such dense biological masses, such as pus, mucus, sputum, and blood clots, is influenced not only by the concentration of the hydrogen peroxide but also by the alkalinity of the solution and the temperature of the interaction medium. Increasing the solutions temperature from 24C26C to 45C55C and its alkalinity from pH 7.0 to 8.48.5 enhances the pyolytic, mucolytic, hemolytic, bleaching, and oxygen-releasing activity of hydrogen peroxide solutions. Simple heating achieves the desired level of hyperthermia, while the addition of sodium bicarbonate provides the indicated alkalinity. Hyperthermia, according to the laws of physics, reduces the viscosity of biological masses, increasing their fluidity, permeability to the antiseptic solution, miscibility, and solubility in it. Furthermore, hyperthermia accelerates the rate of chemical, physicochemical, and biochemical processes, according to the Arrhenius law. The elevated temperature of interacting media speeds up the alkaline saponification process of proteins and protein-lipid complexes, which constitute the colloidal basis of biological masses. Additionally, hyperthermia intensifies the enzymatic decomposition of hydrogen peroxide into water and oxygen gas, facilitated by the enzyme catalase present in most biological masses. The released molecular oxygen generates gas bubbles that mimic cold boiling, leading to the explosion of biological masses, transforming them into a fluffy white foam. Oxygen in an alkaline environment oxidizes biological pigments, including hemoglobin and its metabolites of different colors, resulting in their discoloration.

Oxygen-releasing biomaterials for chronic wounds breathing: From theoretical mechanism to application prospect

Chronic wounds have always been considered as "gordian knots" in medicine, in which hypoxia plays a key role in blocking healing. To address this challenge, although tissue reoxygenation therapy based on hyperbaric oxygen therapy (HBOT) has been performed clinically for several years, the bench to bedside still urges the evolution of oxygen-loading and -releasing strategies with explicit benefits and consistent outcome. The combination of various oxygen carriers with biomaterials has gained momentum as an emerging therapeutic strategy in this field, exhibiting considerable application potential. This review gives an overview of the essential relationship between hypoxia and delayed wound healing. Further, detailed characteristics, preparation methods and applications of various oxygen-releasing biomaterials (ORBMs) will be elaborated, including hemoglobin, perfluorocarbon, peroxide, and oxygen-generating microorganisms, those biomaterials are applied to load, release or generate a vast of oxygen to relieve the hypoxemia and bring the subsequent cascade effect. The pioneering papers regarding to the ORBMs practice are presented and trends toward hybrid and more precise manipulation are summarized.

Natural and biocompatible dressing unit based on tea carbon dots modified core-shell electrospun fiber for diabetic wound disinfection and healing

Wound infection and healing in patients with diabetes is one of the complex problems in trauma treatment. Therefore, designing and preparing an advanced dressing membrane for treating the wounds of such patients is essential. In this study, a zein film with biological tea carbon dots (TCDs) and calcium peroxide (CaO₂) as the main components for promoting diabetic wound healing was prepared by an electrospinning technique, which combines the advantages of natural degradability and biosafety. CaO₂ is a biocompatible material with a microsphere structure that reacts with water to release hydrogen peroxide and calcium ions. TCDs with a small diameter were doped in the membrane to mitigate its properties while improving the antibacterial and healing effects of the membrane. TCDs/CaO₂ was mixed with ethyl cellulose-modified zein (ZE) to prepare the dressing membrane. The antibacterial properties, biocompatibility and wound-healing properties of the composite membrane were investigated by antibacterial experiment, cell experiment and a full-thickness skin defect. TCDs/CaO₂ @ZE exhibited significant anti-inflammatory and wound healing-promoting properties in diabetic rats, without any cytotoxicity. This study is meaningful in developing a natural and biocompatible dressing membrane for diabetic wound healing, which shows a promising application in wound disinfection and recovery in patients with chronic diseases.

Studying and Analyzing Humane Endpoints in the Fructose-Fed and Streptozotocin-Injected Rat Model of Diabetes

This work aimed to define a humane endpoint scoring system able to objectively identify signs of animal suffering in a rat model of type 2 diabetes. Sprague-Dawley male rats were divided into control and induced group. The induced animals drink a 10% fructose solution for 14 days. Then, received an administration of streptozotocin (40 mg/kg). Animals' body weight, water and food consumption were recorded weekly. To evaluate animal welfare, a score sheet with 14 parameters was employed. Blood glucose levels were measured at three time points. After seven weeks of initiating the protocol, the rats were euthanized. The induced animals showed weight loss, polyuria, polyphagia, and polydipsia. According to our humane endpoints table, changes in animal welfare became noticeable after the STZ administration. None of the animals hit the critical score limit (four). Data showed that the most effective parameters to assess welfare in this type 2 diabetes rat induction model were dehydration, grooming, posture, abdominal visualization, and stool appearance. The glycemia was significantly higher in the induced group when compared to the controls (p < 0.01). Induced animals' murinometric and nutritional parameters were significantly lower than the controls (p < 0.01). Our findings suggest that in this rat model of type 2 diabetes with STZ-induced following fructose consumption, our list of humane endpoints is suitable for monitoring the animals' welfare.

Current scenario of traditional medicines in management of diabetic foot ulcers: A review

Diabetic foot infections and diabetic foot ulcers (DFU) cause significant suffering and are often recurring. DFU have three important pathogenic factors, namely, microangiopathy causing local tissue anoxia, neuropathy making the foot prone to injuries from trivial trauma, and local tissue hyperglycaemia favouring infection and delaying the wound healing. DFU have been the leading cause for non-traumatic amputations of part or whole of the limb. Western medicines focus mainly on euglycaemia, antimicrobials, debridement and wound cover with grafts, and off-loading techniques. Advances in euglycaemic control, foot care and footwear, systemic antimicrobial therapy, and overall health care access and delivery, have resulted in an overall decrease in amputations. However, the process of wound care after adequate debridement remains a major cost burden globally, especially in developing nations. This process revolves around two basic concerns regarding control/eradication of local infection and promotion of faster healing in a chronic DFU without recurrence. Wound modulation with various dressings and techniques are often a costly affair. Some aspects of the topical therapy with modern/Western medicines are frequently not addressed. Cost of and compliance to these therapies are important as both the wounds and their treatment are “chronic.” Naturally occurring agents/medications from traditional medicine systems have been used frequently in different cultures and nations, though without adequate clinical base/relevance. Traditional Chinese medicine involves restoring yin-yang balance, regulating the ‘chi’, and promoting local blood circulation. Traditional medicines from India have been emphasizing on ‘naturally’ available products to control wound infection and promote all the aspects of wound healing. There is one more group of chemicals which are not pharmaceutical agents but can create acidic milieu in the wound to satisfy the above-mentioned basic concerns. Various natural and plant derived products (e.g., honey, aloe vera, oils, and calendula) and maggots are also used for wound healing purposes. We believe that patients with a chronic wound are so tired physically, emotionally, and financially that they usually accept native traditional medicine which has the same cultural base, belief, and faith. Many of these products have never been tested in accordance to “evidence-based medicine.” There are usually case reports and experience-based reports about these products. Recently, there have been some trials (in vitro and in vivo) to verify the claims of usage of traditional medicines in management of DFU. Such studies show that these natural products enhance the healing process by controlling infection, stimulating granulation tissue, antimicrobial action, promoting fibroblastic activity and collagen deposition, etc. In this review, we attempt to study and analyse the available literature on results of topical traditional medicines, which are usually advocated in the management of DFU. An integrated and ‘holistic’ approach of both modern and traditional medicine may be more acceptable to the patient, cost effective, and easy to administer and monitor. This may also nevertheless lead to further improvement in quality of life and decrease in the rates of amputations for DFU.

Signaling pathways in cutaneous wound healing

Wound healing is a very complex process, where variety of different pathways is activated, depending on the phase of healing. Improper or interrupted healing might result in development of chronic wounds. Therefore, novel approaches based on detailed knowledge of signalling pathways that are activated during acute or chronic cutaneous wound healing enables quicker and more effective healing. This review outlined new possibilities of cutaneous wound healing by modulation of some signalling molecules, e.g., gasotransmitters, or calcium. Special focus is given to gasotransmitters, since these bioactive signalling molecules that can freely diffuse into the cell and exert antioxidative effects. Calcium is an important booster of immune system and it can significantly contribute to healing process. Special interest is given to chronic wounds caused by diabetes mellitus and overcoming problems with the inflammation.

Self-locomotive, antimicrobial microrobot (SLAM) swarm for enhanced biofilm elimination

Biofilm is a major cause of infections and infrastructure deterioration, largely due to molecular diffusion restrictions that hamper the antimicrobial activity of traditional antibiotics and disinfectants. Here, we present a self-locomotive, antimicrobial microrobot (SLAM) swarm that can penetrate, fracture, and detach biofilm and, in turn, nullify bacterial resistance to antibiotics. The SLAM is assembled by loading a controlled mass of manganese oxide nanosheets on diatoms with the polydopamine binder. In hydrogen peroxide solution, SLAMs produce oxygen bubbles that generate thrust to penetrate the rigid and dense Pseudomonas aeruginosa biofilm and self-assemble into a swarm that repeatedly surrounds, expands, and bursts oxygen bubbles. The resulting cavities continue to deform and fracture extracellular polymeric substances from microgrooved silicone substrates and wounded skin explants while decreasing the number of viable bacterial cells. Additionally, SLAM allows irrigating water or antibiotics to access the residual biofilm better, thus enhancing the synergistic efficacy in killing up to 99.9% of bacterial cells.

Sterilization of Lucilia sericata (Diptera: Calliphoridae) Eggs for Maggot Debridement Therapy

Maggot debridement therapy (MDT) is a therapy with the medical use of sterile fly larvae of certain species, particularly those within the Calliphoridae family including green bottle fly, Lucilia sericata (Meigan, Diptera: Calliphoridae), for treating chronically infected wounds and ulcers. Lucilia sericata flies were maintained under insectary conditions, and the eggs were sterilized using three treatments: hydrogen peroxide solutions, used as a hand disinfectant (Treatment 1-T1), hydrogen peroxide, surface disinfectant (Treatment 2-T2), and SaniHigene (Treatment 3-T3) and the control (without treatment). All three treatment caused the complete sterilization of eggs, and no bacterial colonies were found on the blood agar culture. The egg hatching rate after 72 h was much higher than after 24 h. Egg mortality in hydrogen peroxide solutions, T1 and T2, was 3-4% and less than in solution T3 (13%). Owing to less mortality and more sterility of the eggs, the aforementioned solutions are suggested to be appropriate for sterility in maggot therapy.

Comparison Benefit between Hydrogen Peroxide and Adrenaline in Tonsillectomy: A Randomized Controlled Study

This study aimed to further evaluate the benefit of topical hemostasis agents in tonsillectomy. We compared the clinical effects of topical application between hydrogen peroxide and adrenaline in tonsillectomy. Overall, 60 patients (120 tonsils) were prospectively enrolled for tonsillectomy between February 2018 and December 2020. The patients were randomly assigned to either the hydrogen peroxide or adrenaline group. Then, tonsillectomy was performed using hydrogen peroxide as a hemostatic agent on the assigned side, while adrenaline was applied to the other side. All procedures were performed by a surgeon who was blinded to the randomization. The outcome measurements of operation time, intraoperative blood loss, postoperative pain, and hemorrhage events were analyzed. The intraoperative blood loss was significantly lower in the hydrogen peroxide group than in the adrenaline group (9.99 ± 4.51 mL vs. 13.87 ± 6.32 mL; p = 0.0). The median operation time was also significantly lower in the hydrogen peroxide group (8.02 ± 3.59 min vs. 9.22 ± 3.88 min; p = 0.019). Meanwhile, the visual analogue scale (VAS) scores were significantly higher in the hydrogen peroxide group (4.98 ± 1.94 vs. 4.27 ± 1.97; p = 0.001). The topical application of hydrogen peroxide as a hemostatic agent effectively decreases the operation time and intraoperative blood loss. Thus, hydrogen peroxide can be used as a routine hemostatic agent for bleeding control in tonsillectomy.

Dynamic Role of Oxygen in Wound Healing: A Microbial, Immunological, and Biochemical Perspective

A wound is a temporary break in the continuity of the protective skin barrier. Wound healing is central in maintaining the body's normal homeostatic mechanism, and open wounds raise the risk of microbial infection and amputation. A successful wound healing event is achieved through a series of evolutionarily conserved biochemical pathways orchestrated by various cytokines, growth factors, and immune cells. Chronic wounds are generally oxygen-deficient, and wound hypoxia impairs the wound healing process. Therefore, the use of external oxygen may improve wound health by reducing wound hypoxia, promoting tissue regeneration and granulation tissue formation, reducing anaerobic bacteria colonization, and promoting the growth of beneficial aerobic bacteria. Relevant data were searched and gathered from scientific databases, including PubMed, ScienceDirect, and Google Scholar using relevant keywords, such as "Chronic Wounds", "Topical Oxygen Therapy", "Inflammatory Markers/ Lactate/ Matrix Metalloproteinase", "Collagen", and "Wound Healing". Relevant articles were shortlisted and used in the present study. Chronic wounds show higher expression of pro-inflammatory mediators, such as C-reactive protein, and higher levels of tissue-degrading matrix metalloproteinases. In addition, chronic wounds are generally oxygen-deficient, and wound hypoxia is directly associated with wound deterioration. Several microbial, immunological, and biochemical markers show a direct association with the oxygen availability in the wound. Therefore, a detailed understanding of these microbial, immunological, and biochemical markers will certainly help clinicians understand the interplay between various factors and topical oxygen therapy and may improve patient outcomes.

Evidenz in der lokalen Therapie chronischer Wunden: Was ist gesichert?

Chronische Wunden sind ein komplexes Symptom verschiedener Grunderkrankungen. Sie können bspw. vaskulärer, metabolischer oder immunologischer Genese sein. Auch wenn die Therapie dieser Grunderkrankungen im Vordergrund steht und zielführend ist, so beeinflussen diese Wunden die Lebensqualität der einzelnen Patienten oder Patientinnen stark. Zur Lokaltherapie chronischer Wunden steht ein breites Portfolio an Möglichkeiten zur Verfügung. Anders als in anderen Bereichen der Medizin ist die Evidenz für die verschiedenen Lokaltherapeutika meist gering. Deshalb rücken Experten-Empfehlungen und Leitlinien an ihre Stelle, die sinnvolle Behandlungspfade aufzeigen. Die wichtigsten Fragestellungen in der täglichen Praxis betreffen die Wahl und Effektivität der Wundspülung und des Wunddebridements, das Exsudatmanagement, den Einsatz von antimikrobiellen Wirkstoffen in Lösungen und Wundauflagen, die Unterdruck-Wundtherapie (NPWT) und die Indikationsstellung zur Kompressionstherapie. Trotz des Mangels an Evidenz folgt die Behandlung chronischer Wunde einigen grundlegenden Prinzipien, die im folgenden Artikel inklusive der dazugehörigen Behandlungsempfehlungen dargestellt werden.

In Vitro Anti-Biofilm Activity of Hydrogen-Peroxide Generating Electrochemical Bandage Against Yeast Biofilms

Wound infections are caused by bacteria and/or fungi. The presence of fungal biofilms in wound beds presents a unique challenge, as fungal biofilms may be difficult to eradicate. The goal of this work was to assess the in vitro anti-biofilm activity of a H₂O₂-producing electrochemical bandage (e-bandage) against 15 yeast isolates representing commonly-encountered species. Time-dependent decreases in viable biofilm CFU counts of all isolates tested were observed, resulting in no visible colonies with 48 hours of exposure by plate culture. Fluorescence microscopic analysis showed extensive cell membrane damage of biofilm cells after e-bandage treatment. Reductions in intracellular ATP levels of yeast biofilm cells were recorded post e-bandage treatment. Our results suggest that exposure to H₂O₂-producing e-bandages reduce in vitro viable cell counts of yeast biofilms, making this a potential new topical treatment approach for fungal wound infections.

Reduced Susceptibility and Increased Resistance of Bacteria against Disinfectants: A Systematic Review

Disinfectants are used to reduce the concentration of pathogenic microorganisms to a safe level and help to prevent the transmission of infectious diseases. However, bacteria have a tremendous ability to respond to chemical stress caused by biocides, where overuse and improper use of disinfectants can be reflected in a reduced susceptibility of microorganisms. This review aims to describe whether mutations and thus decreased susceptibility to disinfectants occur in bacteria during disinfectant exposure. A systematic literature review following PRISMA guidelines was conducted with the databases PubMed, Science Direct and Web of Science. For the final analysis, 28 sources that remained of interest were included. Articles describing reduced susceptibility or the resistance of bacteria against seven different disinfectants were identified. The important deviation of the minimum inhibitory concentration was observed in multiple studies for disinfectants based on triclosan and chlorhexidine. A reduced susceptibility to disinfectants and potentially related problems with antibiotic resistance in clinically important bacterial strains are increasing. Since the use of disinfectants in the community is rising, it is clear that reasonable use of available and effective disinfectants is needed. It is necessary to develop and adopt strategies to control disinfectant resistance.

What Is the Optimal Irrigation Solution in the Management of Periprosthetic Hip and Knee Joint Infections?

BACKGROUND

Thorough irrigation and debridement using an irrigation solution is a well-established treatment for both acute and chronic periprosthetic joint infections (PJIs). In the absence of concrete data, identifying the optimal irrigation agent and protocol remains challenging.

METHODS

A thorough review of the current literature on the various forms of irrigations and their additives was performed to evaluate the efficacy and limitations of each solution as pertaining to pathogen eradication in the treatment of PJI. As there is an overall paucity of high-quality literature comparing irrigation additives to each other and to any control, no meta-analyses could be performed. The literature was therefore summarized in this review article to give readers concise information on current irrigation options and their known risks and benefits.

RESULTS

Antiseptic solutions include povidone-iodine, chlorhexidine gluconate, acetic acid, hydrogen peroxide, sodium hypochlorite, hypochlorous acid, and preformulated commercially available combination solutions. The current literature suggests that intraoperative use of antiseptic irrigants may play a role in treating PJI, but definitive clinical studies comparing antiseptic to no antiseptic irrigation are lacking. Furthermore, no clinical head-to-head comparisons of different antiseptic irrigants have identified an optimal irrigation solution.

CONCLUSION

Further high-quality studies on the optimal irrigation additive and protocol for the management of PJI are warranted to guide future evidence-based decisions.

Growth Factors, Reactive Oxygen Species, and Metformin-Promoters of the Wound Healing Process in Burns?

Burns can be caused by various factors and have an increased risk of infection that can seriously delay the wound healing process. Chronic wounds caused by burns represent a major health problem. Wound healing is a complex process, orchestrated by cytokines, growth factors, prostaglandins, free radicals, clotting factors, and nitric oxide. Growth factors released during this process are involved in cell growth, proliferation, migration, and differentiation. Reactive oxygen species are released in acute and chronic burn injuries and play key roles in healing and regeneration. The main aim of this review is to present the roles of growth factors, reactive oxygen species, and metformin in the healing process of burn injuries.

Contribution of SOS genes to H2O2-induced apoptosis-like death in Escherichia coli

Hydrogen peroxide (H₂O₂) is a debriding agent that damages the microbial structure and function by generating various reactive oxygen species (ROS). H₂O₂-produced hydroxyl radical (OH∙) also exerts oxidative stress on microorganisms. The spread of antibiotic-resistance in bacteria is a serious issue worldwide, and greater efforts are needed to identify and characterize novel antibacterial mechanisms to develop new treatment strategies. Therefore, this study aimed to clarify the relationship between H₂O₂ and Escherichia coli and to elucidate a novel antibacterial mechanism(s) of H₂O₂. Following H₂O₂ exposure, increased levels of 8-hydroxydeoxyguanosine and malondialdehyde indicated that H₂O₂ accelerates oxidation of bacterial DNA and lipids in E. coli. As oxidative damage worsened, the SOS response was triggered. Cell division arrest and resulting filamentous cells were identified in cells, indicating that LexA was involved in DNA replication. It was also verified that RecA, a representative SOS gene, helps self-cleavage of LexA and acts as a bacterial caspase-like protein. Our findings also showed that dinF is essential to preserve E. coli from H₂O₂-induced ROS, and furthermore, demonstrated that H₂O₂-induced SOS response and SOS genes participate differently in guarding E. coli from oxidative stress. As an extreme SOS response is considered apoptosis-like death (ALD) in bacteria, additional experiments were performed to examine the characteristics of ALD. DNA fragmentation and membrane depolarization appeared in H₂O₂-treated cells, suggesting that H₂O₂ causes ALD in E. coli. In conclusion, our investigations revealed that ALD is a novel antibacterial mode of action(s) of H₂O₂ with important contributions from SOS genes.

Hydrogen Peroxide: Its Use in an Extensive Acute Wound to Promote Wound Granulation and Infection Control - Is it Better Than Normal Saline?

Background: Hydrogen peroxide (H₂O₂) is used as a topical antiseptic in contaminated wounds caused by road traffic accidents. It kills bacteria by producing oxidation through local, nascent, free oxygen radicals. It also removes dirt from the wound due to its frothing action. H₂O₂ is synthesized by various cells as an active biochemical agent that affects cell biological behavior through complex chemical reactions. H₂O₂ has also been used as a wound cleaning agent, removing debris, preventing infection, and causing hemostasis due to its exothermic reaction with blood. Despite its widespread use, there is scanty literature on its use to promote granulation tissue formation. Objective: In the orthopaedics literature, studies on H₂O₂ use are very limited and its potential is underestimated. In the present study, we would like to report our protocol of use of H₂O₂ for its tremendous potential for stimulating granulation and early wound healing. Material and Methods: A total of 53 patients with large acute extensive lower limb contaminated wounds reported to the emergency department have been included with and without lower limb fracture. In group A (43 patients) wound management was done using 7% H₂O₂ and group B (10 patients) was treated by only saline dressing as a control group. Results: In the present study, daily dressing by 7% H₂O₂ solution and provide solution gives excellent results compared to the Saline group. Granulation tissue appeared much earlier with a mean SD 6.3 ± 6.8 days in the hydrogen peroxide group as compared to the Saline group where granulation tissue appeared in 9.3 ± 8.4 days. Conclusion: Spontaneous wound healing is a controlled balance between destructive and healing processes. It is mandatory to remove damaged tissue to promote healing by secondary intention and minimize infection. The dynamic effect of H₂O₂ promotes faster healing, stimulates granulation, and minimizes infection by oxidative stress.

Protective effects of cannabidiol on the membrane proteins of skin keratinocytes exposed to hydrogen peroxide via participation in the proteostasis network

Hydrogen peroxide (H₂O₂) is widely used in clinical practice due to its antiseptic properties and its ability to heal wounds. However, due to its involvement in the formation of ROS, H₂O₂ causes several side effects, including disorders of the metabolism of skin cells and the development of chronic inflammation mediated by oxidative stress. Therefore, this study evaluated the effects of cannabidiol (CBD), a phytocannabinoid known for its antioxidant and anti-inflammatory properties, on the proteome of keratinocyte membranes exposed to H₂O₂. Overall, the hydrogen peroxide caused the levels of several proteins to increase, while the treatment with CBD prevented these changes. Analysis of the protein-protein interaction network showed that the significant changes mainly involved proteins with important roles in the proteasomal activity, protein folding processes (regulatory subunit of the proteasome 26S 6A, beta proteasome subunit type 1, chaperonin 60 kDa), protein biosynthesis (40S ribosomal proteins S16, S2 and ubiquitin-S27a), regulation of the redox balance (carbonyl reductase [NADPH] 1 and NAD(P)H [quinone] 1 dehydrogenase) and cell survival (14-3-3 theta protein). Additionally, CBD reduced the total amount of MDA, 4-HNE and 4-ONE-protein adducts. Therefore, we conclude that CBD partially prevents the changes induced by hydrogen peroxide by reducing oxidative stress and maintaining proteostasis networks. Moreover, our results indicate that combination therapy with CBD may bring a promising approach in the clinical use of hydrogen peroxide by preventing its pro-oxidative and pro-inflammatory effect through potential participation of CBD in membrane mediated molecular signaling.

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CBD prevents H₂O₂-induced changes in keratinocytes membrane proteomic profile.

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Protective effect of CBD could be mediated by alterations in proteostasis network.

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CBD promotes antioxidative and pro-survival cellular response.

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CBD reduces formation of lipid peroxidation products-protein adducts.

Evidenz in der lokalen Therapie chronischer Wunden: Was ist gesichert?

Chronische Wunden sind ein komplexes Symptom verschiedener Grunderkrankungen. Sie können bspw. vaskulärer, metabolischer oder immunologischer Genese sein. Auch wenn die Therapie dieser Grunderkrankungen im Vordergrund steht und zielführend ist, so beeinflussen diese Wunden die Lebensqualität der einzelnen Patienten oder Patientinnen stark. Zur Lokaltherapie chronischer Wunden steht ein breites Portfolio an Möglichkeiten zur Verfügung. Anders als in anderen Bereichen der Medizin ist die Evidenz für die verschiedenen Lokaltherapeutika meist gering. Deshalb rücken Experten-Empfehlungen und Leitlinien an ihre Stelle, die sinnvolle Behandlungspfade aufzeigen. Die wichtigsten Fragestellungen in der täglichen Praxis betreffen die Wahl und Effektivität der Wundspülung und des Wunddebridements, das Exsudatmanagement, den Einsatz von antimikrobiellen Wirkstoffen in Lösungen und Wundauflagen, die Unterdruck-Wundtherapie (NPWT) und die Indikationsstellung zur Kompressionstherapie. Trotz des Mangels an Evidenz folgt die Behandlung chronischer Wunde einigen grundlegenden Prinzipien, die im folgenden Artikel inklusive der dazugehörigen Behandlungsempfehlungen dargestellt werden.

Naturally-derived targeted therapy for wound healing: Beyond classical strategies

This review summarizes the four processes of wound healing in the human body (hemostasis, inflammatory, proliferation, and remodeling) and the most current research on the most important factors affecting cutaneous wound healing and the underlying cellular and/or molecular pathways. Local factors, including temperature, oxygenation, and infection, and systemic factors, such as age, diabetes, sex hormones, genetic components, autoimmune diseases, psychological stress, smoking and obesity are also addressed. A better understanding of the role of these factors in wound repair could result in the development of therapeutics that promote wound healing and resolve affected wounds. Additionally, natural products obtained from plants and animals are critical targets for the discovery of novel biologically significant pharmacophores, such as medicines and agrochemicals. This review outlines the most recent advances in naturally derived targeted treatment for wound healing. These are plant-derived natural products, insect-derived natural products, marine-derived natural products, nanomaterial-based wound-healing therapeutics (metal- and non-metal-based nanoparticles), and natural product-based nanomedicine to improve the future direction of wound healing. Natural products extracted from plants and animals have advanced significantly, particularly in the treatment of wound healing. As a result, the isolation and extraction of bioactive compounds from a variety of sources can continue to advance our understanding of wound healing. Undescribed bioactive compounds or unexplored formulations that could have a role in today's medicinal arsenal may be contained in the abundance of natural products and natural product derivatives.

Dynamically and Spatially Controllable Albumin-Based Hydrogels for the Prevention of Postoperative Adhesion

Since the degree of severity and the geometry of wounds vary, it is necessary to prepare an antiadhesive hydrogel that possesses dynamically controllable material properties, exhibits biodegradability, and possesses drug-releasing properties. Injectable, oxygen peroxide-sensitive, and photo-cross-linkable hydrogels that permit in situ dynamic and spatial control of their physicochemical properties were synthesized for the prevention of postoperative adhesion. Albumin is the most abundant protein in blood serum and serves as a carrier for several molecules that exhibit poor water solubility. It is therefore a suitable biomaterial for the fabrication of hydrogels since it presents a low risk of life-threatening complications and does not require immunosuppressive therapy for preventing graft rejection. The physicochemical properties of this hydrogel can then be spatially postadjusted via transdermal exposure to light to release drugs, depending on what is required for the injury. A significant reduction in postoperative peritoneal adhesion was observed in an animal model involving severe sidewall and bowel abrasions. This study demonstrated that the fabricated dually cross-linked, albumin-based hydrogels have great potential in such applications because they showed a low immune response, easy handling, full wound coverage, and tunable biodegradability. Precise spatial and controllable drug-release profiles may also be achieved via in situ transdermal post-tuning of the biomaterials, depending on the injury.

Therapeutic Properties of Honey for the Management of Wounds; Is There a Role in the Armamentarium of Diabetic Foot Ulcer Treatment? Results From In vitro and In vivo Studies

Diabetic foot ulcers are one of the most dreadful complications of diabetes mellitus and efforts to accelerate diabetic wound healing are of paramount importance to prevent ulcer infections and subsequent lower-limb amputations. There are several treatment approaches for the management of diabetic foot ulcers and honey seems to be a safe and cost-effective therapeutic approach on top of standard of care. The aim of this review was to summarize the therapeutic properties of honey and the data regarding its possible favorable effects on diabetic wound healing. A literature search of articles from 1986 until April 2021 was performed using MEDLINE, EMBASE, and the Cochrane Library to assess for studies examining the therapeutic wound healing properties of honey, it's in vitro effect, and the efficacy and/or mechanism of action of several types of honey used for the treatment of diabetic animal wounds. Honey has antioxidant, anti-inflammatory, and antibacterial properties and in vitro studies of keratinocytes and fibroblasts, as well as studies in diabetic animal models show that treatment with honey is associated with increased re-epithelialization and collagen production, higher wound contraction, and faster wound healing. The use of honey could be a promising approach for the management of diabetic foot ulcers.

Antisense yycG modulates the susceptibility of Staphylococcus aureus to hydrogen peroxide via the sarA

Background

The infectious pathogen Staphylococcus aureus (S. aureus) is primarily associated with osteomyelitis. Hydrogen peroxide drainage is an effective antimicrobial treatment that has been adopted to combat S. aureus infections. Previous investigations have indicated that the antisense RNA (asRNA) strategy negatively modulates S. aureus YycFG TCS, and it significantly disrupts biofilm formation. However, the effects of the antisense yycG RNA (ASyycG) strategy on the susceptibility of biofilm-producing S. aureus to hydrogen peroxide and the mechanisms underlying this effect have not been elucidated to date.

Results

Overexpression of ASyycG inhibited the transcription of biofilm formation-related genes, including sarA and icaA. Additionally, the CFU counts and the live bacterial ratios of ASyycG biofilm-producing S. aureus treated with H₂O₂ were notably reduced across the groups. Notably, the predicted promoter regions of the sarA and icaA genes were directly regulated by YycF.

Conclusions

ASyycG was observed to sensitize biofilm-producing S. aureus to H₂O₂ intervention synergistically via the sarA and thus may represent a supplementary strategy for managing osteomyelitis. However, future in-depth studies should attempt to replicate our findings in animal models, such as the rat osteomyelitis model.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02218-x.

Role of hydrogen peroxide in intra-operative wound preparation based on an in vitro fibrin clot degradation model

Three per cent hydrogen peroxide (H₂O₂) is widely used to irrigate acute and chronic wounds in the surgical setting and clinical experience tells us that it is more effective at removing dried-on blood than normal saline alone. We hypothesise that this is due to the effect of H₂O₂ on fibrin clot architecture via fibrinolysis. We investigate the mechanisms and discuss the clinical implications using an in vitro model. Coagulation assays with normal saline (NaCl), 1% and 3% concentrations of H₂O₂ were performed to determine the effect on fibrin clot formation. These effects were confirmed by spectrophotometry. The effects of 1%, 3% and 10% H₂O₂ on the macroscopic and microscopic features of fibrin clots were assessed at set time intervals and compared to a NaCl control. Quantitative analysis of fibrin networks was undertaken to determine the fibre length, diameter, branch point density and pore size. Fibrin clots immersed in 1%, 3% and 10% H₂O₂ demonstrated volume losses of 0.09-0.25mm³/min, whereas those immersed in the normal saline gained in volume by 0.02±0.13 mm³/min. Quantitative analysis showed that H₂O₂ affects the structure of the fibrin clot in a concentration-dependent manner, with the increase in fibre length, diameter and consequently pore sizes. Our results support our hypothesis that the efficacy of H₂O₂ in cleaning blood from wounds is enhanced by its effects on fibrin clot architecture in a concentration- and time-dependent manner. The observed changes in fibre size and branch point density suggest that H₂O₂ is acting on the quaternary structure of the fibrin clot, most likely via its effect on cross-linking of the fibrin monomers and may therefore be of benefit for the removal of other fibrin-dependent structures such as wound slough.

Hydrogen peroxide-producing electrochemical bandage controlled by a wearable potentiostat for treatment of wound infections

Chronic wound infections caused by biofilm-forming microorganisms represent a major burden to healthcare systems. Treatment of chronic wound infections using conventional antibiotics is often ineffective due to the presence of bacteria with acquired antibiotic resistance and biofilm-associated antibiotic tolerance. We previously developed an electrochemical scaffold that generates hydrogen peroxide (H₂ O₂ ) at low concentrations in the vicinity of biofilms. The goal of this study was to transition our electrochemical scaffold into an H₂ O₂ -generating electrochemical bandage (e-bandage) that can be used in vivo. The developed e-bandage uses a xanthan gum-based hydrogel to maintain electrolytic conductivity between e-bandage electrodes and biofilms. The e-bandage is controlled using a lightweight, battery-powered wearable potentiostat suitable for use in animal experiments. We show that e-bandage treatment reduced colony-forming units of Acinetobacter buamannii biofilms (treatment vs. control) in 12 h (7.32 ± 1.70 vs. 9.73 ± 0.09 log₁₀ [CFU/cm² ]) and 24 h (4.10 ± 12.64 vs. 9.78 ± 0.08 log₁₀ [CFU/cm² ]) treatments, with 48 h treatment reducing viable cells below the limit of detection of quantitative and broth cultures. The developed H₂ O₂ -generating e-bandage was effective against in vitro A. baumannii biofilms and should be further evaluated and developed as a potential alternative to topical antibiotic treatment of wound infections.

Origin and Use of Hydrogen Peroxide in Neurosurgery

Hydrogen peroxide (H2O2) is a chemical with a wide range of applications. This includes its use in the medical field, in which its use has been ubiquitous but is most useful as an antiseptic and in achieving hemostasis. Neurosurgeons have been using H2O2 for well over a century, primarily for its hemostatic and antiseptic effects. This is in spite of the fact that the actual effectiveness of H2O2 as an antiseptic is questionable, and its use, in general, may be more dangerous than it appears. We review the application of H2O2 in medicine generally and, more specifically, in neurosurgery. This review outlines the reasoning behind the use of H2O2 as an antiseptic and details why it may not be as effective as one might think. We also detail its use as a hemostatic agent in neurosurgery, reviewing a number of techniques in which it has been useful in this role. Finally, we review the documented cases of complications associated with the use of H2O2 in neurosurgery. Ultimately, we conclude that the use of H2O2 in neurosurgery be reconsidered because of its lack of effectiveness as an antiseptic and potentially fatal complications.

Ferrocene-functionalized hybrid hydrogel dressing with high-adhesion for combating biofilm

Bacterial infection is a common phenomenon in the process of postoperative wound healing. In severe cases, it may even lead to life-threatening, which brings a heavy burden to the clinical treatment and causes huge losses to the society and economy. As one of the most commonly applied medical materials for wound treatment, hydrogel dressings are mainly used to cover and protect wounds and provide a favorable environment to facilitate wound healing. In this work, we developed an antibacterial hydrogel dressing (Fc-PAAM) with high adhesion, which is consisted of polyacrylamide (PAM) hydrogel framework and polyacrylic acid-functionalized (PAA) with ferrocene (Fc). Morphology, adhesion and pressure resistance of PAAM hydrogel were confirmed by using scanning electron microscope (SEM) and universal testing machine, and Fc decoration in the hydrogel network was well demonstrated by using Fourier transform infrared spectroscopy (FT-IR). Ultraviolet-visible spectroscopy (UV-vis) displayed that the Fc-PAAM hydrogel had excellent peroxidase-like activity as well. It not only exhibited prominent antimicrobial activity against Gram (+/-) bacteria, but also performed high efficiency in preventing the formation of biofilms. In addition, in vivo experiments indicated that this adhesive dressing could significantly prevent bacterial infections. Compared with other clinical treatment methods, this kind of hydrogel is not easy to cause bacterial resistance, and the used raw materials are easy to obtain and low in price, which can amplify the antibacterial properties of H₂O₂ and provide a new opportunity for the treatment of clinical bacterial infections.

Doxycycline Hyclate Modulates Antioxidant Defenses, Matrix Metalloproteinases, and COX-2 Activity Accelerating Skin Wound Healing by Secondary Intention in Rats

The main objective of this study was to investigate the action of doxycycline hyclate (Dx) in the skin wound healing process in Wistar rats. We investigated the effect of Dx on inflammatory cell recruitment and production of inflammatory mediators via in vitro and in vivo analysis. In addition, we analyzed neovascularization, extracellular matrix deposition, and antioxidant potential of Dx on cutaneous repair in Wistar rats. Male animals (n = 15) were divided into three groups with five animals each (protocol: 72/2017), and three skin wounds (12 mm diameter) were created on the back of the animals. The groups were as follows: C, received distilled water (control); Dx1, doxycycline hyclate (10 mg/kg/day); and Dx2, doxycycline hyclate (30 mg/kg/day). The applications were carried out daily for up to 21 days, and tissues from different wounds were removed every 7 days. Our in vitro analysis demonstrated that Dx led to macrophage proliferation and increased N-acetyl-β-D-glucosaminidase (NAG) production, besides decreased cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and metalloproteinases (MMP), which indicates that macrophage activation and COX-2 inhibition are possibly regulated by independent mechanisms. In vivo, our findings presented increased cellularity, blood vessels, and the number of mast cells. However, downregulation was observed in the COX-2 and PGE2 expression, which was limited to epidermal cells. Our results also showed that the downregulation of this pathway benefits the oxidative balance by reducing protein carbonyls, malondialdehyde, nitric oxide, and hydrogen peroxide (H2O2). In addition, there was an increase in the antioxidant enzymes (catalase and superoxide dismutase) after Dx exposure, which demonstrates its antioxidant potential. Finally, Dx increased the number of types I collagen and elastic fibers and reduced the levels of MMP, thus accelerating the closure of skin wounds. Our findings indicated that both doses of Dx can modulate the skin repair process, but the best effects were observed after exposure to the highest dose.

Formulation of a reactive oxygen producing calcium sulphate cement as an anti-bacterial hard tissue scaffold

Prophylactic antibiotic bone cements are extensively used in orthopaedics. However, the development of antimicrobial resistance to antibiotics, demonstrates a need to find alternative treatments. Herein, an antimicrobial honey (SurgihoneyRO-SHRO) has been successfully incorporated into a calcium sulphate (CS) based cement to produce a hard tissue scaffold with the ability to inhibit bacterial growth. Antimicrobial properties elicited from SHRO are predominantly owed to the water-initiated production of reactive oxygen species (ROS). As an alternative to initially loading CS cement with SHRO, in order to prevent premature activation, SHRO was added into the already developing cement matrix, locking available water into the CS crystal structure before SHRO addition. Promisingly, this methodology produced > 2.5 times (715.0 ± 147.3 μM/mL/g) more ROS over 24 h and exhibited a compressive strength (32.2 ± 5.8 MPa) comparable to trabecular bone after 3 weeks of immersion. In-vitro the SHRO loaded CS scaffolds were shown to inhibit growth of clinically relevant organisms, Staphylococcus aureus and Pseudomonas aeruginosa, with comparable potency to equivalent doses of gentamicin. Encouragingly, formulations did not inhibit wound healing or induce an inflammatory response from osteoblasts. Overall this study highlights the prophylactic potential of CS-SHRO cements as an alternative to traditional antibiotics.