Skin Wound Infection Research Articles

An injectable adhesive antibacterial hydrogel wound dressing for infected skin wounds

It's an exigent need for the improvement of novel antibacterial wound dressings with the increasing threats of drug resistance caused by excessive use of the antibiotics. In this work, an injectable, adhesive, hemostatic, biocompatible and bactericidal hydrogel wound dressing was fabricated. An injectable hydrogel can fill the irregular wound due to the characteristic of reversible sol-gel transition, whereas conventional dressings don't possess this ability. Oxidized alginate (ADA) and catechol-modified gelatin (Gel-Cat) were selected as the polymer backbones and they can crosslink in situ through double dynamic bonds, which were Schiff base and catechol-Fe coordinate bond; polydopamine decorated silver nanoparticles (PDA@Ag NPs) were also introduced into the hydrogel network. The double dynamic bonds endowed the hydrogel with injectable ability, shorter gelation time and enhanced mechanical property. And the aldehyde and catechol groups on the chains of ADA and Gel-Cat gave the hydrogel excellent adhesiveness. In addition, the PDA@Ag NPs in this system play two roles: one is bactericidal agent which can release from the hydrogel to kill the bacteria; the other is photothermal agent to convert 808 nm near-infrared light into heat to realize sterilization. In vitro study, the hydrogel displayed bactericidal ability against S. aureus and E. coli whether in photothermal antimicrobial test or agar diffusion test. In vivo test also testified that the hydrogel had a prominent therapeutic effect on infected wound through reducing inflammatory response and accelerating angiogenesis. Thus, we anticipate that our double dynamic bonds crosslinked hydrogel with PDA@Ag NPs as the antimicrobial agent can be a novel therapeutic way for infected wounds.

Controlled release of metal phenolic network protected phage for treating bacterial infection

Phage is a promising therapeutic agent for treating antibiotic resistant bacteria. However, in the process of treatment, phage may be cleared by the immune system and cleaved by protease, which could affect the efficacy of phage. In order to solve the above problems, phage encapsulation is usually adopted. In this study, we employed metal phenolic network (MPN) for efficient phage encapsulation which could protect phage from the cleavage of protease, and keep cytotoxicity weak. In the model of skin wound infection, the encapsulated phage could be released in response to pH change to achieve good antibacterial effect. Furthermore, the MPN encapsulation could prolong the T4 phage residence time at the wound. Our findings suggest that MPN can be a promising material for phage encapsulation.

Injectable and self‐healing hydrogels with tissue adhesiveness and antibacterial activity as wound dressings for infected wound healing

AbstractThe design of wound dressings with excellent self‐healing ability, adequate adhesion, good biocompatibility, and potential antibacterial ability is of great significance for the healing of infected wounds arising from human activities. Herein, a series of multi‐functional hydrogel dressings, poly(ionized isocyanoethyl methacrylate‐glutamine)/poly(hexamethylene guanidine) (iGx/PHMGy) hydrogels, were obtained through homopolymerization of fully ionized isocyanoethyl methacrylate‐glutamine (iIEM‐Gln) in the presence of poly(hexamethylene guanidine) (PHMG), in which strong hydrogen bonds were formed among urea groups in the P (iIEM‐Gln) chain to form a stable hydrogel network. The prepared iGx/PHMGy hydrogels exhibited adequate self‐healing ability and tissue adhesion, which could be firmly adhered to the wound surface and remained intact during application. In addition, the presence of PHMG imparted good antibacterial activity to the hydrogels for the effective promotion of the wound healing in S. aureus infected skin wound on mice. Overall, this multi‐functional hydrogel provides a facile and effective strategy for the design of infected wound dressings, and may show great potential in clinical applications.

Polyhexamethylene biguanide chemically modified cotton with desirable hemostatic, inflammation-reducing, intrinsic antibacterial property for infected wound healing

Medical cotton dressing is cheap and widely used in diversified fields, but in the application of promoting wound healing, the continuous research of multifunctional medical cotton dressing is still of great significance. Here, we developed a fresh type of antibacterial cotton dressing through a succinct strategy based on chemically anchoring polyhexamethylene biguanide (PHMB). Intriguingly, after PHMB modification, the cotton dressing exhibited outstanding antibacterial performance which could maintain >99.99% antibacterial rate after several treatments, including washing 50 times, repeated use 10 times, UV irradiation for 7 days, cationic dyes dying, and conditioned under 90 °C water bath for 2 h. In addition, the water contact angle of cotton dressing increased dramatically from 0° to 111°, which could facilitate bacterial adhesion, thus further enhance the antibacterial efficiency, and easily remove the bacterial debris. Apart from that, the developed cotton dressing showed good cytocompatibility, promoted blood clotting and expression of platelets, and promoted the wound healing process in the infection intervened skin wound model. Taken together, this antibacterial cotton dressing with desirable blood clotting, sustained protection against bacterial infection and bacterial removal features shows the potential to be a candidate for infected skin wound healing.

Development of Chitosan‐Assisted Fe3O4@SiO2 Magnetic Nanostructures Functionalized with Nisin as a Topical Combating System against Vancomycin‐Intermediate Staphylococcus aureus (VISA) Skin Wound Infection in Mice

The clinical significance of vancomycin‐intermediate S. aureus (VISA) infections is intensified by its tendency to develop resistance to antimicrobials and persistent infections. The decreasing effectiveness of the antimicrobials available is now seriously compromised; thus, there is an emergent need to invent new classes of antimicrobial agents that can rapidly and efficiently eradicate infections. Fe3O4@SiO2@chitosan (CS) nanocomposites were successfully synthesized and then decorated with nisin to gain Fe3O4/SiO2/CS/nisin‐based magnetic nanostructures (Fe3O4@SiO2@CS‐NISIN). The nanomaterials were characterized comparatively via FTIR (Fourier transform infrared spectroscopy), XRD (X‐ray diffraction), FE‐SEM (field emission scanning electron microscopes), DLS (dynamic light scattering), and VSM (vibrating sample magnetometer) methods. The methyl thiazol tetrazolium (MTT) assay was performed to determine the inhibitory effects of antibacterial agents on the cell viability. The in vitro bactericidal effect of all compounds was characterized using the microdilution assay. Finally, the topical antibacterial efficacy of free nisin, Fe3O4@SiO2@CS, and Fe3O4@SiO2@CS‐NISIN nanocomposites against murine superficial wound infection models was determined. The functionalized nanocomposites were more efficient in suppressing bacterial growth in vitro and in vivo compared to the same quantities of untargeted nanocomposites. MTT results showed acceptable biocompatibility of all nanoformulations, and no substantial difference in the cell viability was recorded between treated cells and untreated control. These results suggest that Fe3O4@SiO2@CS‐NISIN nanocomposites can be served as an alternative antimicrobial agent in innovative and emerging technologies to treat a variety of staphylococcal infections.

ANTIPSEUDOMONAL ACTIVITY OF METABOLIC COMPLEXES OF L. RHAMNOSUS GG AND S. BOULARDII AGAINST THE POLYRESISTENT PATHOGEN IN IN VITRO AND IN VIVO TESTS.

The aim: Explore the antimicrobial properties of lactobacilli's metabolites and combination of lactobacilli's and saccharomycetes' metabolites with different concentrations (in vitro) and to test the effectiveness of samples with minimum inhibitory concentration on infected polyresistant strain P. aeruginosa skin wounds (in vivo) for the possibility of creating prophylactic antimicrobial agents. Materials and methods: Metabolic complexes (L. rhamnosus GG and S. boulardi) were obtained by culturing lactobacilli or lactobacilli and saccharomycetes in lactobacilli disintegrates. The sensitivity of Pseudomonas aeruginosa PR (in vitro) to them was determined by the microtechnique of serial dilutions in a liquid nutrient medium. In vivo, 0.9 % sodium chloride solution (control) or lactobacillus metabolic complex (experiment, treatment group) was applied to infected skin wounds or, in addition, immediately before the infection, to the wound and then to infected wounds (experiment, prophylactic-treatment group). Results: There was observed the decrease of the infectious process of skin wounds in the prophylactic-treatment group (3.25-3.4 times; p=0.01 related to control samples) compared with the treatment group (2.05-2.25 times; p=0.02) by the wound healing rate (day 5). The healing rate of control wounds (day 11) coincided with the rates of experimental wounds in the prophylactic-treatment group (day 8), indicating that the use of lactobacilli metabolites promotes the acceleration of healing by almost three days. Conclusions: Metabolic complexes of probiotic microorganisms are promising for construction on their new class of antimicrobials for the effective pharmacoprophylaxis and pharmacotherapy.

Treatment of Fungal-Infected Diabetic Wounds with Low Temperature Plasma.

Diabetes mellitus renders patients susceptible to chronic wounds and various infections. Regarding the latter, fungal infections are of particular concern since, although they are the source of significant morbidity and mortality in immunocompromised patients, they are generally resistant to conventional treatment and a definite treatment strategy has not yet been established. Herein, we report the treatment of skin wounds in a diabetic rat model, infected by Candida albicans, with low temperature helium plasma generated in a hand-held atmospheric jet device. A fungal infection was induced on two dorsal skin wounds of the diabetic rats, and one wound was treated with the plasma jet whereas the other served as a control. Histological analysis revealed accelerated skin wound healing and decreased evidence of fungal infection in the plasma-treated group, as compared to the control group. Regeneration of the epidermis and dermis, collagen deposition, and neovascularization were all observed as a result of plasma treatment, but without wound contraction, scar formation or any evidence of thermal damage to the tissue. These findings demonstrate that the He plasma jet is remarkably effective in diabetic skin wounds infected by Candida albicans, thereby providing a promising medical treatment option for diabetes mellitus patients with skin wound and fungal infections.

One-Step Synthesis of Multifunctional Chitosan Hydrogel for Full-Thickness Wound Closure and Healing.

Multifunctional hydrogel as a sealant or wound dressing with high adhesiveness and excellent antibacterial activity is highly desirable in clinical applications. In this contribution, one-step synthetic hydrogel based on quaternized chitosan (QCS), tannic acid (TA), and ferric iron (Fe(III)) is developed for skin incision closure and Staphylococcus aureus (S. aureus)-infected wound healing. In this hydrogel system, the ionic bonds and hydrogen bonds between QCS and TA form the main backbone of hydrogel, the metal coordination bonds between TA and Fe(III) (catechol-Fe) endow hydrogel with excellent adhesiveness and (near-infrared light) NIR-responsive photothermal property, and these multiple dynamic physical crosslinks enable QCS/TA/Fe hydrogel with flexible self-healing ability and injectability. Moreover, QCS/TA/Fe hydrogel possesses superior antioxidant, anti-inflammatory, hemostasis, and biocompatibility. Also, it is safe for vital organs. The data from the mouse skin incision model and infected full-thickness skin wound model presented the high wound closure effectiveness and acceleration of the wound healing process by this multifunctional hydrogel, highlighting its great potential in wound management.

P150 UTILISATION OF OVINE REINFORCED TISSUE MATRIX IN PAEDIATRIC RECONSTRUCTIVE SURGERY

Abstract Aim Abdominal and thoracic reconstructive surgery has always been an aspect of surgical care in children for conditions such as congenital abdominal wall defects, large hiatus herniae, incisional herniae and chest wall defects following tumour surgery. Biosynthetic matrices are ideal for reconstructive surgery in the paediatric population as consideration needs to be given to future growth and potential need for reoperation. Moreover, the use of synthetic materials in this setting is known to be associated with long term issues. We present the results of our experience with ovine reinforced tissue matrix1 in paediatric reconstructive surgery. Material and Methods All patients who underwent an operation at our institution using the biosynthetic matrix from March 2019 to April 2021 were identified retrospectively by searching theatre databases. Patient demographics, diagnoses and case notes were reviewed. Results The biosynthetic matrix was used in 26 children, (15 male and 11 female). Median age at insertion was 5.1 years (2.1 – 7.1 years). Median weight at insertion was 14.0kg (11.3 – 28.1kg). Patients had a history of hiatus hernia (n = 10), exomphalos (n = 6), emergency laparotomy (n = 3), congenital diaphragmatic hernia (n = 2) sternal sarcoma (n = 1), rib sarcoma (n = 1), gastroschisis (n = 1), recurrent umbilical hernia (n = 1) and direct inguinal hernia (n = 1). There were no hernial recurrences. There was a surgical site occurrence (SSO) in 12% - skin dehiscence (n = 2) and wound infection (n = 1). Median length of follow up was 7.9 months (4.5-9.0 months). Conclusions Our series demonstrates that ovine biosynthetic matrices can be used safely in paediatric reconstructive surgery with excellent outcomes and a very low rate of SSO. 1. OviTex®-TELA Bio

Enzymatically-crosslinked gelatin hydrogels containing paenipeptin and clarithromycin against carbapenem-resistant pathogen in murine skin wound infection

BackgroundThe recent rise and spread of carbapenem-resistant pathogens pose an urgent threat to public health and has fueled the search for new therapies. Localized delivery of topical antibiotics is an alternative for the treatment of infected wounds caused by drug-resistant pathogens. In this study, we aimed to develop antimicrobial-loaded hydrogels for topical treatment of wound infections in a murine skin wound infection.ResultsPaenipeptin analogue 1, a linear lipopeptide, potentiated clarithromycin against multidrug-resistant Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, and Klebsiella pneumoniae. Enzymatically-crosslinked gelatin hydrogels were developed to encapsulate paenipeptin analogue 1 and clarithromycin. The encapsulated antimicrobials were gradually released from hydrogels during incubation, reaching 75.43 and 53.66% for paenipeptin and clarithromycin, respectively, at 24 h. The antimicrobial-loaded hydrogels containing paenipeptin and clarithromycin synergistically resulted in 5-log reduction in carbapenem-resistant A. baumannii within 6 h in vitro. Moreover, the antimicrobial-loaded hydrogels reduced 3.6- and 2.5-log of carbapenem-resistant A. baumannii when treated at 4 or 20 h post infection, respectively, in a murine skin wound infection.ConclusionsEnzymatically-crosslinked gelatin hydrogels loaded with paenipeptin analogue 1 and clarithromycin exhibited potent therapeutic efficacy against carbapenem-resistant A. baumannii in murine skin wound infection.

Mechanistic Studies of Antibiotic Adjuvants Reducing Kidney's Bacterial Loads upon Systemic Monotherapy.

We describe the design and attributes of a linear pentapeptide-like derivative (C14(ω5)OOc10O) screened for its ability to elicit bactericidal competences of plasma constituents against Gram-negative bacteria (GNB). In simpler culture media, the lipopeptide revealed high aptitudes to sensitize resilient GNB to hydrophobic and/or efflux-substrate antibiotics, whereas in their absence, C14(ω5)OOc10O only briefly delayed bacterial proliferation. Instead, at low micromolar concentrations, the lipopeptide has rapidly lowered bacterial proton and ATP levels, although significantly less than upon treatment with its bactericidal analog. Mechanistic studies support a two-step scenario providing a plausible explanation for the lipopeptide’s biological outcomes against GNB: initially, C14(ω5)OOc10O permeabilizes the outer membrane similarly to polymyxin B, albeit in a manner not necessitating as much LPS-binding affinity. Subsequently, C14(ω5)OOc10O would interact with the inner membrane gently yet intensively enough to restrain membrane-protein functions such as drug efflux and/or ATP generation, while averting the harsher inner membrane perturbations that mediate the fatal outcome associated with bactericidal peers. Preliminary in vivo studies where skin wound infections were introduced in mice, revealed a significant efficacy in affecting bacterial viability upon topical treatment with creams containing C14(ω5)OOc10O, whereas synergistic combination therapies were able to secure the pathogen’s eradication. Further, capitalizing on the finding that C14(ω5)OOc10O plasma-potentiating concentrations were attainable in mice blood at sub-maximal tolerated doses, we used a urinary tract infection model to acquire evidence for the lipopeptide’s systemic capacity to reduce the kidney’s bacterial loads. Collectively, the data establish the role of C14(ω5)OOc10O as a compelling antibacterial potentiator and suggest its drug-like potential.

New Perspectives on Old and New Therapies of Staphylococcal Skin Infections: The Role of Biofilm Targeting in Wound Healing.

Among the most common complications of both chronic wound and surgical sites are staphylococcal skin infections, which slow down the wound healing process due to various virulence factors, including the ability to produce biofilms. Furthermore, staphylococcal skin infections are often caused by methicillin-resistant Staphylococcus aureus (MRSA) and become a therapeutic challenge. The aim of this narrative review is to collect the latest evidence on old and new anti-staphylococcal therapies, assessing their anti-biofilm properties and their effect on skin wound healing. We considered antibiotics, quorum sensing inhibitors, antimicrobial peptides, topical dressings, and antimicrobial photo-dynamic therapy. According to our review of the literature, targeting of biofilm is an important therapeutic choice in acute and chronic infected skin wounds both to overcome antibiotic resistance and to achieve better wound healing.

Silver Peroxide Nanoparticles for Combined Antibacterial Sonodynamic and Photothermal Therapy.

Metal peroxide nanoparticles designed to elevate the oxidative stress are considered a promising nanotherapeutics in biomedical applications, including chemotherapy, photodynamic therapy, and bacterial disinfection. However, their lack of specificity towards the therapeutic target can cause toxic side effects to healthy tissues. Here, silver peroxide nanoparticles (Ag2 O2 NPs) capable of controlled reactive oxygen species (ROS) release are synthesized. The release of bactericidal Ag+ ions and ROS is strictly regulated by external stimuli of ultrasound (US) and near-infrared (NIR) light. In vitro and in vivo investigations show that the Ag2 O2 NPs present enhanced antibacterial and antibiofilm capabilities with a killing efficiency >99.9999% in 10min, significantly accelerate multi-drug resistant Staphylococcus aureus infected skin wound closure with excellent cytocompatibility and hemocompatibility. This work not only provides the first paradigm for fabricating silver peroxide nanoparticle but also introduces a highly efficient noninvasive and safe therapeutic modality for combating bacterial infectious diseases.

Alleviation of Pseudomonas aeruginosa Infection by Propeptide-Mediated Inhibition of Protease IV.

ABSTRACTPseudomonas aeruginosa, an opportunistic human pathogen, expresses protease IV (PIV) for infection. Since the PIV activity can be inhibited by its propeptide, we tried to alleviate the severity of P. aeruginosa infection using the purified PIV propeptide (PIVpp). The PIVpp treatment of P. aeruginosa could significantly inhibit the PIV activity and reduce the virulence of P. aeruginosa in multiple invertebrate infection models, such as nematodes, brine shrimp, and mealworms. The effectiveness of PIVpp was further confirmed using mouse skin infection and acute/chronic lung infection models. The amount of PIVpp that inhibited the PIV activity of P. aeruginosa by 65% could alleviate the severity of infection significantly in all of the skin and acute/chronic lung infections. In addition, the PIVpp treatment of P. aeruginosa facilitated the healing of the skin wound infections and repressed the growth of P. aeruginosa in the infected lung. The PIVpp itself did not cause the induction of inflammatory cytokines or have any harmful effects on host tissues and did not affect bacterial growth. Taken together, P. aeruginosa infections can be alleviated by PIVpp treatment.IMPORTANCE Pseudomonas aeruginosa is a highly antibiotic-resistant pathogen and is extremely difficult to treat. Instead of using conventional antibiotics, we attempted to alleviate P. aeruginosa infection using factors that P. aeruginosa itself produces naturally. Extracellular proteases are powerful virulence factors and important targets to control the P. aeruginosa infections. Propeptides are originally expressed as part of extracellular proteases, inhibiting their activity until they go out of the cell, preventing them from becoming toxic to the cells themselves. We confirmed, from multiple animal experiments, that treating P. aeruginosa with the purified propeptide can alleviate its infectivity. Propeptides specifically inhibit only their cognate protease without inhibiting other essential proteases of the host. The development of resistance can be avoided because the propeptide-mediated inhibition is an inherent mechanism of P. aeruginosa; hence, it will be difficult for P. aeruginosa to alter this mechanism. Since propeptides do not affect bacterial growth, there is no selective pressure to develop resistant cells.

Modification of cotton gauzes with poly(acrylic acid) and poly(methacrylic acid) using gamma radiation for drug loading studies

Cotton gauzes are highly versatile medical devices for treating wounds due to their excellent absorption capacity and because they avoid contact between the wound and the environment. As materials of priority use, it is possible to take advantage of their ubiquity and use them as delivery systems for antimicrobial drugs that effectively treat skin wound infections. For this reason, this study proposes the modification of cotton gauzes through the grafting of pH-sensitive polymers, such as poly (acrylic acid) and poly (methacrylic acid), as a means of achieving drug delivery. The grafting process was carried out using gamma radiation, and the successful modification of the devices was verified with analytical techniques such as SEM, FTIR-ATR, TGA, and DSC, finding the novel properties of these modified materials. The grafted gauzes show a critical pH close to 4.7, which would allow for its application to some acidic skin wounds. In addition to the pH-buffering properties of the material, it was possible to load vancomycin onto the grafted materials as a pathway for the development of antimicrobial materials.

Ameliorative and Disinfection Effects of Ultraviolet-C Radiation on Experimentally Induced and Infected Skin Wounds: A Mice Model Study.

Only ultraviolet-C (UV-C) from UV lights, which are emitted by the sun and absorbed by the atmosphere's ozone layer, does not reach the Earth's surface. UV-C is a powerful disinfection method that is commonly used to sterilize fluids, air, and surfaces. There is a little knowledge of the effects of UV-C radiation on living bodies. The purpose of this study is to examine the ameliorative effect of UV-C on skin lesions in mice that have been experimentally created and infected with Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus sp. In total, 32 mice were used, and 4 mm skin defects were created and lesions infected with bacteria. Half of the mice in each group were treated with 254 nm UV-C twice a day for 4 days before being euthanatized. Blood samples were collected for hematological analysis, while skin samples were collected for microbiological, pathological, and immunohistochemical examinations. In addition, pathological examinations were performed on visceral organ samples. UV-C treatment caused rapid healing and complete or significant disinfection of skin lesions. Moreover, UV-C treatment reduced caspase-3 expressions in lesioned areas, according to immunochemistry. There were no pathological findings in visceral organs as a result of UV-C treatment. This study found that UV-C can be used to treat and disinfect infected skin lesions in short period and repeated doses.

Antimicrobial, Antibiofilm, and Anti-persister Activities of Penfluridol Against Staphylococcus aureus.

Staphylococcus aureus has increasingly attracted global attention as a major opportunistic human pathogen owing to the emergence of biofilms (BFs) and persisters that are known to increase its antibiotic resistance. However, there are still no effective antimicrobial agents in clinical settings. This study investigated the antimicrobial activity of penfluridol (PF), a long-acting antipsychotic drug, against S. aureus and its clinical isolates via drug repurposing. PF exhibited strong bactericidal activity against S. aureus, with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 4–8 and 16–32 μg/ml, respectively. PF could significantly inhibit biofilm formation and eradicate 24 h preformed biofilms of S. aureus in a dose-dependent manner. Furthermore, PF could effectively kill methicillin-resistant S. aureus (MRSA) persister cells and demonstrated considerable efficacy in a mouse model of subcutaneous abscess, skin wound infection, and acute peritonitis caused by MRSA. Notably, PF exerted almost no hemolysis activity on human erythrocytes, with limited cytotoxicity and low tendency to cause resistance. Additionally, PF induced bacterial membrane permeability and ATP release and further caused membrane disruption, which may be the underlying antibacterial mechanism of PF. In summary, our findings suggest that PF has the potential to serve as a novel antimicrobial agent against S. aureus biofilm- or persister-related infections.

Chemical Fingerprint Profiles and Pharmacodynamic Investigation for Quality Evaluation of Moxa Smoke by UHPLC in a Rat Model of Superficial Infection

Introduction Moxibustion, a traditional Chinese medicine technique, involves the use of moxa smoke from Folium Artemisia argyi to treat various disorders, especially superficial infections. However, there is a higher health risk for people exposed to high levels of moxa smoke for extended durations. Here, we report the first ultra-high-performance liquid chromatography (UHPLC) fingerprint profiles and pharmacodynamic evaluation of moxa smoke, as well as evaluation of its aqueous solution on a rat model of superficial infection. Methods A novel method for moxa smoke fingerprint profiling was developed using UHPLC under characteristic wavelength. Chromatographic peaks were further analyzed by ultra-high-performance liquid chromatography quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF/MS). 12 sample batches obtained from various Chinese provinces were then analyzed using similarity evaluation, clustering analysis, and principal component analysis. The pharmacodynamics of moxa smoke and moxa aqueous solution were investigated on a rat model of acute skin wound infection. Results UHPLC fingerprint profiles of 12 batches of moxa smoke were generated at 270 nm wavelength and 21 chromatographic peaks extracted as common peaks. Similarity between the 12 batches ranged from 0.341 to 0.982. Based on cluster analysis, the 12 batches of moxa smoke samples were clustered into five groups. Principal component analysis showed that the cumulative contribution of the three principal components reached 90.17%. Eigenvalues of the first, second, and third principal components were 10.794, 6.504, and 1.638, respectively. The corresponding variance contribution rates were 51.40%, 30.97%, and 7.80%, respectively. Pharmacological analysis found that wound healing was slow in the model group relative to the mupirocin ointment, moxa smoke, and aqueous moxa smoke solution groups. Histological analysis revealed markedly reduced tissue inflammation in rats treated with moxa smoke or its aqueous solution. Conclusions Moxa smoke and its aqueous solution significantly promote wound healing upon superficial infection. A novel quality control method for moxa smoke was established and evaluated for the first time. As its main effects are unchanged, the transformation of moxa smoke into aqueous moxa smoke improves safety and is a simple and controllable process.

PEGylated Graphene Oxide Carried OH-CATH30 to Accelerate the Healing of Infected Skin Wounds.

BackgroundThe treatment of Staphylococcus aureus (S. aureus)-infected wounds is difficult. It causes extreme pain to tens of thousands of patients and increases the cost of medical care. The antimicrobial peptide OH-CATH30 (OH30) has a good killing activity against S. aureus and can play a role in accelerating wound healing and immune regulation. Therefore, it shows great potential for wound healing.PurposeThe aim of this study was to overcome the short half-life and easy enzymolysis of OH30 by using graphene oxide conjugated with polyethylene glycol to load OH30 (denoted as PGO-OH30), as well as to evaluate its effect on wounds infected by S. aureus.MethodsPGO-OH30 nanoparticles were prepared by π–π conjugation and characterized. Their cell cytotoxicity, cell migration, infectious full-thickness dermotomy models, and histopathology were evaluated.ResultsCharacterization and cytotoxicity experiments revealed that the PGO-OH30 drug-delivery system had good biocompatibility and excellent drug-delivery ability. Cell-migration experiments showed that PGO-OH30 could promote the migration of human immortalized keratinocytes (HaCaT) cells compared with the control group (P<0.05). In a mouse model of skin wound infection, PGO-OH30 accelerated skin-wound healing and reduced the amount of S. aureus in wounds compared with the control group (P<0.05). In particular, on day 7, the number of S. aureus was 100 times lower in the PGO-OH30 group than in the control group.ConclusionThe PGO-OH30 drug-delivery system had good biocompatibility and excellent drug-delivery ability, indicating its good therapeutic effect on a skin wound-infection model.

Decompressive craniectomy is a life-saving procedure in malignant MCA infarction.

Objectives:To investigate the indications, timings, and outcomes of decompressive craniectomy (DC) performed for malignant middle cerebral artery (MCA) infarctions at our tertiary care center.Methods:This retrospective case series involved patients who underwent DC for malignant MCA infarction at King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, between January 2012 and December 2018. Demographic, clinical, and radiological data were collected, and stroke- and surgery-related complications and discharge outcomes were assessed.Results:Eighteen patients (mean age: 50±10 years), of whom 13 (72%) were men, underwent DC during the study period. Of the patients, 9 (50%) had severe stroke (NIHSS 16–25), 10 (56%) had right MCA infarction, and 11 (61%) received either intravenous thrombolysis or endovascular thrombectomy or their combination. Indications for surgery included clinical deterioration as seen in 16 (89%) patients, ipsilateral pupillary dilatation as seen in 11 (61%) patients, and signs of raised intracranial pressure in 6 (33%) patients. Surgery was performed within 48 h in 14 (78%) patients. The mean Intensive Care Unit stay was 15±7 days. Seven (39%) patients were discharged home and 3 (17%) were transferred to an inpatient rehabilitation unit, and 2 (11%) patients died. All patients had stroke-related complications; one (6%) patient developed cerebrospinal fluid leak, 3 (17%) had sunken skin flap syndrome and wound infection each, and 2 (11%) developed epidural hematoma.Conclusion:The DC was life-saving in the our patients with malignant MCA infarction. Most of the patients had surgery within 48 hours. More than one-third of the patients were discharged home, while mortality occurred in only 2 patients. Moreover, stroke- and surgery-related complications were common in our cohort.