Wound pathophysiology, infection and therapeutic options

Silk Sericin and Its Composite Materials with Antibacterial Properties to Enhance Wound Healing: A Review

Wound infections may disrupt the normal wound-healing process. Large amounts of antibiotics are frequently used to prevent pathogenic infections; however, this can lead to resistance development. Biomaterials possessing antimicrobial properties have promising applications for reducing antibiotic usage and promoting wound healing. Silk sericin (SS) has been increasingly explored for skin wound healing applications owing to its excellent biocompatibility and antioxidant, antimicrobial, and ultraviolet-resistant properties. In recent years, SS-based composite biomaterials with a broader antimicrobial spectrum have been extensively investigated and demonstrated favorable efficacy in promoting wound healing. This review summarizes various antimicrobial agents, including metal nanoparticles, natural extracts, and antibiotics, that have been incorporated into SS composites for wound healing and elucidates their mechanisms of action. It has been revealed that SS-based biomaterials can achieve sustained antimicrobial activity by slow-release-loaded antimicrobial agents. The antimicrobial-loaded SS composites may promote wound healing through anti-infection, anti-inflammation, hemostasis, angiogenesis, and collagen deposition. The manufacturing methods, benefits, and limitations of antimicrobial-loaded SS materials are briefly discussed. This review aims to enhance the understanding of new advances and directions in SS-based antimicrobial composites and guide future biomedical research.

Direct metagenomics investigation of non-surgical hard-to-heal wounds: a review

BACKGROUND

Non-surgical chronic wounds, including diabetes-related foot diseases (DRFD), pressure injuries (PIs) and venous leg ulcers (VLU), are common hard-to-heal wounds. Wound evolution partly depends on microbial colonisation or infection, which is often confused by clinicians, thereby hampering proper management. Current routine microbiology investigation of these wounds is based on in vitro culture, focusing only on a limited panel of the most frequently isolated bacteria, leaving a large part of the wound microbiome undocumented.

METHODS

A literature search was conducted on original studies published through October 2022 reporting metagenomic next generation sequencing (mNGS) of chronic wound samples. Studies were eligible for inclusion if they applied 16 S rRNA metagenomics or shotgun metagenomics for microbiome analysis or diagnosis. Case reports, prospective, or retrospective studies were included. However, review articles, animal studies, in vitro model optimisation, benchmarking, treatment optimisation studies, and non-clinical studies were excluded. Articles were identified in PubMed, Google Scholar, Web of Science, Microsoft Academic, Crossref and Semantic Scholar databases.

RESULTS

Of the 3,202 articles found in the initial search, 2,336 articles were removed after deduplication and 834 articles following title and abstract screening. A further 14 were removed after full text reading, with 18 articles finally included. Data were provided for 3,628 patients, including 1,535 DRFDs, 956 VLUs, and 791 PIs, with 164 microbial genera and 116 species identified using mNGS approaches. A high microbial diversity was observed depending on the geographical location and wound evolution. Clinically infected wounds were the most diverse, possibly due to a widespread colonisation by pathogenic bacteria from body and environmental microbiota. mNGS data identified the presence of virus (EBV) and fungi (Candida and Aspergillus species), as well as Staphylococcus and Pseudomonas bacteriophages.

CONCLUSION

This study highlighted the benefit of mNGS for time-effective pathogen genome detection. Despite the majority of the included studies investigating only 16 S rDNA, ignoring a part of viral, fungal and parasite colonisation, mNGS detected a large number of bacteria through the included studies. Such technology could be implemented in routine microbiology for hard-to-heal wound microbiota investigation and post-treatment wound colonisation surveillance.

Bacterial fluorescence imaging as a predictor of skin graft integration in burn wounds

BACKGROUND

Split-thickness skin graft (STSG)1 integration rates are susceptible to improvement. Infection and/or biofilm should be appropriately addressed prior to grafting to improve the likelihood of graft-take. Incorporating technological aids such as fluorescence (FL)2 imaging (MolecuLight®), which accurately locates areas of bacterial loads above 104 CFU/gr, for graft site assessment and preparation could yield better outcomes.

METHODS

This single-center, prospective observational study included adult burn patients with previously infected wounds that had been deemed clinically and microbiologically clean and were therefore candidates for grafting. Prior to grafting, a FL imaging assessment (blinded to the surgical team) localized areas positive for moderate-high bacterial loads (>104 CFU/gr). Intra-operatively, a standard swab sample from the recipient site was collected by the surgical team. Postoperatively, areas positive/negative for FL and areas of graft take and failure were overlapped and measured (cm2) over a 2D schematic. The performance and accuracy of FL imaging and swab sampling in relation to graft outcomes were assessed.

RESULTS

38 patients were enrolled in the study. The mean total body surface area (TBSA)3 involvement was 14.5 ± 12.4 % [range 0.8 - 40.2 %]. 25/38 of the subjects enrolled had complete graft take while 13 had partial graft losses. There were no total losses. FL-imaging was positive in 100 % of losses versus 31 % (4/13) of the swab microbiology. FL-imaging was found to have a sensitivity of 86 %, specificity of 98 %, PPV of 72 %, NPV of 99 %, and an accuracy of 94 % for predicting any type or range of graft loss in the entire cohort. Meanwhile, the sensitivity of microbiology from swab samples was 30 %, with a specificity of 76 %.

CONCLUSIONS

FL imaging is an accurate method for assessing recipient sites and predicting the outcome of a skin graft among burn patients. These findings suggest that FL imaging can inform better decision-making surrounding grafts that may lead to better outcomes.

LEVEL OF EVIDENCE

Level IIA, Therapeutic study.

16S rRNA seq-identified Corynebacterium promotes pyroptosis to aggravate diabetic foot ulcer

BACKGROUND

Diabetic foot ulcer (DFU) is one of the main chronic complications caused by diabetes, leading to amputation in severe cases. Bacterial infection affects the wound healing in DFU.

METHODS

DFU patients who met the criteria were selected, and the clinical data were recorded in detail. The pus exudate from the patient's foot wound and venous blood were collected for biochemical analysis. The distribution of bacterial flora in pus exudates of patients was analyzed by 16S rRNA sequencing, and the correlation between DFU and pathogenic variables, pyroptosis and immunity was analyzed by statistical analysis. Then, the effects of key bacteria on the inflammation, proliferation, apoptosis, and pyroptosis of polymorphonuclear leukocytes were investigated by ELISA, CCK-8, flow cytometry, RT-qPCR and western blot.

RESULTS

Clinical data analysis showed that Wagner score was positively correlated with the level of inflammatory factors, and there was high CD3+, CD4+, and low CD8+ levels in DFU patients with high Wagner score. Through alpha, beta diversity analysis and species composition analysis, Corynebacterium accounted for a large proportion in DFU. Logistics regression model and Person correlation analysis demonstrated that mixed bacterial infections could aggravate foot ulcer, and the number of bacteria was closely related to inflammatory factors PCT, PRT, immune cells CD8+, and pyroptosis-related proteins GSDMD and NLRP3. Through in vitro experiments, Corynebacterium inhibited cell proliferation, promoted inflammation (TNF-α, PCT, CRP), apoptosis and pyroptosis (IL-1β, LDH, IL-18, GSDMD, NLRP3, and caspase-3).

CONCLUSION

Mixed bacterial infections exacerbate DFU progression with a high predominance of Corynebacterium, and Corynebacterium promotes inflammation, apoptosis and pyroptosis to inhibit DFU healing.

Profiling of Petroselinum sativum (mill.) fuss phytoconstituents and assessment of their biocompatibility, antioxidant, anti-aging, wound healing, and antibacterial activities

Petroselinum sativum, known as parsley, is a fragrant herb that possesses a rich heritage of utilization in traditional medicinal practices. In this study, we annotated the phytocontents of the aqueous and ethanolic extracts of P. sativum and investigated their antioxidant, cytoprotective, antiaging, wound healing, and antibacterial activities. LC-MS/MS analysis of both extracts revealed the presence of 47 compounds belonging to diverse groups including organic acids, phenolic acids, and flavonoids. By MTT assay, the extracts were fully biocompatible on immortalized human keratinocytes (HaCaT) while they inhibited intracellular ROS formation (DCFDA assay) and prevented GSH depletion (DTNB assay) upon UVA exposure. In addition, the extracts were potent in inhibiting the in vitro activities of skin-related enzymes mainly elastase, tyrosinase, collagenase and hyaluronidase. Using the scratch assay, P. sativum aqueous extract significantly enhanced wound closure when compared to untreated HaCaT cells. Moreover, both extracts inhibited Pseudomonas aeruginosa's growth, reduced biofilm formation, and impaired the swimming and swarming motilities. Also, the aqueous extract was able to inhibit the production of bacterial pigments on plates. These findings strongly suggest the usefulness of P. sativum as a source of phytochemicals suitable for dermo-cosmeceutical applications.

Anti-bacterial and anti-inflammatory properties of Vernonia arborea accelerate the healing of infected wounds in adult Zebrafish

BACKGROUND

Management of wounds and healing under impaired conditions are the major challenges faced globally by healthcare workers. Phytocompounds which are anti-microbial and capable of modulating inflammation contribute to overall wound healing and regain of the lost structure and function especially in wounds impaired with polymicrobial infection.

METHODS

An acute cutaneous impaired wound model using adult zebrafish was validated to simulate mammalian wound pathophysiology. This model was used to evaluate phytofractions of Vernonia arborea in the present study, for reduction of infection; myeloperoxidase (MPO) as a marker of infection; neutrophil infiltration and resolution; kinetics of inflammatory cytokines; and wound repair kinetics (viz., nitrite levels and iNoS expression; reepithelisation).

RESULTS

Four fractions which were active in-vitro against five selected wound microbes were shown to reduce ex-vivo microbial bioburden upto 96% in the infected wound tissue. The reduction in CFU correlated with the neutrophil kinetics and MPO enzyme levels in the treated, wound infected zebrafish. Expression of pro-inflammatory cytokines (IL-6 and TNF-α) was downregulated while upregulating anti-inflammatory cytokine (IL-10), and nitric oxide signalling with fourfold increase in iNOS expression. The adult zebrafish wound model could well serve as a standard tool for assessing phytoextracts such as V. arborea for wound healing with anti-microbial properties.

Deferiprone-Gallium-Protoporphyrin Chitogel Decreases Pseudomonas aeruginosa Biofilm Infection without Impairing Wound Healing

Pseudomonas aeruginosa is one of the most common pathogens encountered in clinical wound infections. Clinical studies have shown that P. aeruginosa infection results in a larger wound area, inhibiting healing, and a high prevalence of antimicrobial resistance. Hydroxypyridinone-derived iron chelator Deferiprone (Def) and heme analogue Gallium-Protoporphyrin (GaPP) in a chitosan-dextran hydrogel (Chitogel) have previously been demonstrated to be effective against PAO1 and clinical isolates of P. aeruginosa in vitro. Moreover, this combination of these two agents has been shown to improve sinus surgery outcomes by quickly reducing bleeding and preventing adhesions. In this study, the efficacy of Def-GaPP Chitogel was investigated in a P. aeruginosa biofilm-infected wound murine model over 6 days. Two concentrations of Def-GaPP Chitogel were investigated: Def-GaPP high dose (10 mM Def + 500 µg/mL GaPP) and Def-GaPP low dose (5 mM Def + 200 µg/mL GaPP). The high-dose Def-GaPP treatment reduced bacterial burden in vivo from day 2, without delaying wound closure. Additionally, Def-GaPP treatment decreased wound inflammation, as demonstrated by reduced neutrophil infiltration and increased anti-inflammatory M2 macrophage presence within the wound bed to drive wound healing progression. Def-GaPP Chitogel treatment shows promising potential in reducing P. aeruginosa cutaneous infection with positive effects observed in the progression of wound healing.

A biologically functional bioink based on extracellular matrix derived collagen for 3D printing of skin

Over the past few years, several advancements have been made to develop artificial skin that mimics human skin. Artificial skin manufactured using 3D printing technology that includes all epidermal and dermal components, such as collagen, may offer a viable solution. The skin-specific bioink was derived from digested chicken skin and incorporated into PVA (polyvinyl alcohol) and gelatin. The prepared bioink was further analyzed for its structure, stability, biocompatibility, and wound healing potential in in vitro, in ovo, and in vivo models. The 3D-printed skin showed excellent mechanical properties. In vitro scratch assays showed the proliferation and migration of cells within 24 h. In an in ovo assay, the 3D-printed skin facilitated the attachment of cells to the scaffolds. In the animal study, the quick cellular recruitment at the injury site accelerated wound healing. Further, hydroxyproline content was estimated to be 0.9-1.2 mg/ml, and collagen content was 7.5 %, which confirmed the epithelization. The relative expressions of MMP-9, COMP, TNF-α, and IL-6 genes were found to be increased compared to the control. These results demonstrate that 3D bioprinting represents a suitable technology to generate bioengineered skin for therapeutic and industrial applications in an automated manner.

An objective comparative study of non-surgical cleansing techniques and cleanser types in bacterial burden management

Cleansing is a vital component of effective wound hygiene and biofilm management, often accomplished through vigorous mechanical action or through soaking with moistened gauze. In the present study, a quantitative comparison of the effectiveness of different cleansing techniques and solutions in removing bacteria was conducted on 71 chronic wounds using bacterial fluorescence imaging as a real-time diagnostic for moderate to high bacterial loads. Vigorous gauze cleansing for 30 s proved most effective by reducing bacterial fluorescence by 33.99%, surpassing 10-min soaking in bacterial reduction (13.24%). Among different cleansers, no statistically significant differences in effectiveness were observed, but povidone-iodine showed the strongest trend towards bacterial reduction. Sub-analysis highlighted the superiority of antiseptic cleansers over saline and gentle soap (-33.30% vs. -1.80% bacterial reduction respectively). Five percent acetic acid was also shown to be more effective in removing specific bacterial strains (Pseudomonas aeruginosa). Findings from studies like this contribute to refining wound hygiene guidelines and clinical algorithms for bacterial and biofilm management.

Applications of cold atmospheric plasma in immune-mediated inflammatory diseases via redox homeostasis: evidence and prospects

As a representative technology in plasma medicine, cold atmospheric plasma (CAP) has beneficial outcomes in surface disinfection, wound repair, tissue regeneration, solid tumor therapy. Impact on immune response and inflammatory conditions was also observed in the process of CAP treatment. Relevant literatures were collected to assess efficacy and summarize possible mechanisms of the innovation. CAP mediates alteration in local immune microenvironment mainly through two ways. One is to down-regulate the expression level of several cytokines, impeding further conduction of immune or inflammatory signals. Intervening the functional phenotype of cells through different degree of oxidative stress is the other approach to manage the immune-mediated inflammatory disorders. A series of preclinical and clinical studies confirmed the therapeutic effect and side effects free of CAP. Moreover, several suggestions proposed in this manuscript might help to find directions for future investigation.

Versatile and User-Friendly Anti-infective Hydrogel for Effective Wound Healing

Wound dressings play a crucial role in facilitating optimal wound healing and protecting against microbial infections. However, existing commercial options often fall short in addressing chronic infections due to antibiotic resistance and the limited spectrum of activity against both Gram-positive and Gram-negative bacteria frequently encountered at wound sites. Additionally, complex fabrication processes and cumbersome administration strategies pose challenges for cost-effective wound dressing development. Consequently, there is a pressing need to explore easily engineered biocompatible biomaterials as alternative solutions to combat these challenging wound infections. In this study, we present the development of an anti-infective hydrogel, P-BAC (polymeric bactericidal hydrogel), which exhibits simple administration and promotes efficient wound healing. P-BAC is synthesized via a one-step fabrication method that involves the noncovalent cross-linking of poly(vinyl alcohol), N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride-AgCl nanocomposite, and proline. Remarkably, P-BAC demonstrates broad-spectrum antibacterial activity against both planktonic and stationary cells of clinically isolated Gram-positive and Gram-negative bacteria, resulting in a significant reduction of bacterial load (5-7 log reduction). Moreover, P-BAC exhibits excellent efficacy in eradicating bacterial cells within biofilm matrices (>95% reduction). In vivo experiments reveal that P-BAC accelerates wound healing by stimulating rapid collagen deposition at the wound site and effectively inactivates ∼95% of Pseudomonas aeruginosa cells. Importantly, the shear-thinning property of P-BAC simplifies the administration process, enhancing its practicality and usability. Taken together, our findings demonstrate the potential of this easily administrable hydrogel as a versatile solution for effective wound healing with potent anti-infective properties. The developed hydrogel holds promise for applications in diverse healthcare settings, addressing the critical need for improved wound dressing materials.

Marine Resources Offer New Compounds and Strategies for the Treatment of Skin and Soft Tissue Infections

Bioprospecting of the marine environment for drug development has gained much attention in recent years owing to its massive chemical and biological diversity. Drugs for the treatment of skin and soft tissue infections have become part of the search, mainly with respect to enlarging the number of available antibiotics, with a special focus on multidrug-resistant Gram-positive bacteria, being the major causative agents in this field. Marine resources offer novel natural products with distinct biological activities of pharmaceutical importance, having the chance to provide new chemical scaffolds and new modes of action. New studies advance the field by proposing new strategies derived from an ecosystemic understanding for preventive activities against biofilms and new compounds suitable as disinfectants, which sustain the natural flora of the skin. Still, the development of new compounds is often stuck at the discovery level, as marine biotechnology also needs to overcome technological bottlenecks in drug development. This review summarizes its potential and shows these bottlenecks and new approaches.

Neutrophil-like Biomimic AIE Nanoparticles with High-Efficiency Inflammatory Cytokine Targeting Enable Precise Photothermal Therapy and Alleviation of Inflammation

Although photothermal therapy (PTT) has thrived as a promising treatment for drug-resistant bacterial infections by avoiding the abuse of antibiotics, the remaining challenges that limit the treatment efficiency are the poor targeting properties of infected lesions and low penetration to the cell membrane of Gram-negative bacteria. Herein, we developed a biomimetic neutrophil-like aggregation-induced emission (AIE) nanorobot (CM@AIE NPs) for precise inflammatory site homing and efficient PTT effects. Due to their surface-loaded neutrophil membranes, CM@AIE NPs can mimic the source cell and thus interact with immunomodulatory molecules that would otherwise target endogenous neutrophils. Coupled with the secondary near-infrared region absorption and excellent photothermal properties of AIE luminogens (AIEgens), precise localization, and treatment in inflammatory sites can be achieved, thereby minimizing damage to surrounding normal tissues. Moreover, CM@AIE NP-mediated PTT was stimulated in vivo by a 980 nm laser irradiation, which contributed to the extent of the therapeutic depth and limited the damage to skin tissues. The good biocompatibility and excellent in vitro and in vivo antibacterial effects prove that CM@AIE NPs can provide a strategy for broad-spectrum antibacterial applications.

Multifunctional chitosan/alginate hydrogel incorporated with bioactive glass nanocomposites enabling photothermal and nitric oxide release activities for bacteria-infected wound healing

It is highly desirable to develop novel multifunctional wound dressing materials capable of delivering active molecules capable of resolving bacterial infections and replenishment of appropriate growth factors for bacteria-infected wound healing. Polysaccharides have numerous biomedical benefits and have been widely used to construct biomaterial scaffolds. Herein, multifunctional chitosan/alginate hydrogel decorated with β-cyclodextrin (β-CD) modified polydopamine (PDA)-bioactive glass (BG) nanoparticles (NPs) integrating photothermal performance and nitric-oxide release activities for the treatment of bacterially infected wounds is presented. As the NO precursor N,N'-di-sec-butyl-N,N'-dinitroso-1,4-phenylenediamine (BNN6) encapsulated into the hydrophobic cavity of β-CD on the PDA-coated BG NPs, the resultant NO@CD-PDA/BG NPs, are imparted with the feature of NIR triggered NO release and desired PTT/NO synergetic antibacterial effects. Furthermore, the release of NO, Ca, and Si ions from the NO@CD-PDA/BG NPs, has the benefit of regulating inflammation, promoting fibroblast proliferation, and stimulating angiogenesis. Besides, the chitosan/alginate hydrogel scaffolds provided a suitable microenvironment to accelerate wound healing. By applying the multifunctional chitosan/alginate nanocomposite hydrogel to S. aureus-infected full-thickness skin defect mouse model, the authors demonstrated that chitosan/alginate nanocomposite hydrogel has multiple functions in preventing bacterial infections, accelerating angiogenesis and wound regeneration, indicating promising application in wound healing.

Does the use of epicutaneous vacuum-assisted closure after revision surgery on the spine reduce further wound revision surgery?

PURPOSE

This study aimed to investigate the effect of epicutaneous vacuum therapy on the rate of unplanned spinal wound revisions compared with conventional wound dressing.

METHODS

This retrospective study included patients who underwent unplanned revision spine surgery after primary aseptic spine surgery who were treated at a level I spine centre between December 2011 and December 2019. Patients with revision surgery who required a further unplanned revision surgery during the inpatient stay were considered a treatment failure. The epicutaneous vacuum-assisted closure (Epi-VAC) therapy was the standard treatment method beginning in 2017 (the epi-VAC group). Before, conventional wound dressing was used (the control group (CG)). In addition, a one-to-one matched-pair comparison analysis was performed between both groups.

RESULTS

Of 218 patients, 48 were in the epi-VAC group. The mean age was 65.1 years (epi-VAC 68.2 to CG 64.3 years (P = 0.085)), and the mean body mass index (BMI) was 28.2 kg/m² (epi-VAC 29.4 to CG 27.9 kg/m² (P = 0.16)). No significant differences in the treatment failure rate could be detected between the two groups (epi-VAC 25% to CG 22.4% (P = 0.7)). There was also no significant difference for the matched-pair analysis (epi-VAC 26.1% to CG 15.2% (P = 0.3)). An elevated CRP level (C-reactive protein) immediately before the first wound revision was a significant risk factor for further revision surgery (treatment failure: 135.2 ± 128.6; no treatment failure: 79.7 ± 86.1 mg/l (P < 0.05)).

CONCLUSION

Concerning repeat unplanned wound revision after spinal revision surgery, we cannot demonstrate an advantage of the epicutaneous vacuum therapy over conventional wound dressing.

Inflammatory biomarkers behavior profile among patients following elective degenerative spine surgery and their differences with those coursing with a postoperative spinal infection: Protocol for a Systematic Review

BACKGROUND

The incidence of postoperative spinal infection (PSI) ranges from 0% to 10%, devastatingly affecting the patient prognosis and increasing costs to the healthcare system because of higher morbidity. Postoperative spinal infections require a high level of suspicion as they are difficult to diagnose, especially in the early postoperative state, because of many confounding factors such as clinical symptoms, serum biomarkers rise or confusing imaging studies. Current research has focused on serum biomarkers at the early stages of disease, nevertheless, most rely on retrospective cohorts with serum biomarkers studied individually and at different time points.

OBJECTIVE

To determine the Inflammatory biomarkers behavior profile among patients following elective degenerative spine surgery and their differences with those coursing with postoperative spinal infection.

METHODS

The proposed systematic review will follow the PRISMA statement. This protocol was registered at PROSPERO on January 19th, 2022, obtaining the following register CRD42022304645 on February 19th, 2022. We will include studies related to biomarkers in adult patients operated on because of degenerative spinal diseases, and those developing a postoperative spinal infection. The following information will be extracted: (1)study title; (2)Study Author (3)year; (4)evidence-level; (5)Research-type; (6)diagnosis group (elective postoperative degenerative disease / PSI); (7a)region (Cervical, Thoracic, Lumbosacral, Coccigeal); (7b)Type of infection by anatomical or radiological site, (8)Surgery-Type (including instrumentation or not); (9)number of cases; (10)mean age or individual age; and (11) individual serum biomarker values from the preoperative state up to 90 days postop for both groups including: (10a)interleukine-6, (10b)Presepsine, (10c)Erythrocyte Sedimentation Rate, (10d)Leukocyte Count, (10e)Neutrophil Count, (10f)C-Reactive Protein, (10g)Serum Amyloid, (10h)White Cell Count, (10i)Albumin, (10j)Prealbumin, (10k)Procalcitonin, (10L)Retinol associated protein, (10M)Dickopf-1, (11)postoperative days at symptoms or diagnosis, (12)Type of organism, (13)day of starting antibiotics, (14)duration of treatment and (15)any biases (including comorbidities, especially those affecting immunological status). All biomarkers' data will be presented graphically over time. Figure 1 contains the flow diagram of the methodology.

RESULTS

No ethical approval will be required, as this review is based on published data and does not involve interaction with human participants. The search for this systematic review commenced in February 2021, and we expect to publish the findings in middle 2023.

CONCLUSIONS

The present study will provide the biomarkers' behavior profile for PSI and patients following elective surgery for degenerative spinal diseases from the preoperative period up to 90 days postoperative providing cut-off values at the day of diagnosis. It will provide clinicians with a better background to diagnose based on highly trustable information based on cut-off values from this systematic review. Finally we expect this review to provide a basis for future research on biomarkers to establish more accurate and timely diagnosis in the early stages of illness ultimately impacting the patient's physical and mental health, reducing the disease burden.

CLINICALTRIAL

PROSPERO register ID: CRD42022304645.

Argon Humidification Exacerbates Antimicrobial and Anti-MRSA kINPen Plasma Activity

Gas plasma is a medical technology with antimicrobial properties. Its main mode of action is oxidative damage via reactive species production. The clinical efficacy of gas plasma-reduced bacterial burden has been shown to be hampered in some cases. Since the reactive species profile produced by gas plasma jets, such as the kINPen used in this study, are thought to determine antimicrobial efficacy, we screened an array of feed gas settings in different types of bacteria. Antimicrobial analysis was performed by single-cell analysis using flow cytometry. We identified humidified feed gas to mediate significantly greater toxicity compared to dry argon and many other gas plasma conditions. The results were confirmed by inhibition zone analysis on gas-plasma-treated microbial lawns grown on agar plates. Our results may have vital implications for clinical wound management and potentially enhance antimicrobial efficacy of medical gas plasma therapy in patient treatment.

Use of fluorescence imaging to optimize location of tissue sampling in hard-to-heal wounds

Introduction

Wound microflora in hard-to-heal wounds is invariably complex and diverse. Determining the interfering organisms(s) is therefore challenging. Tissue sampling, particularly in large wounds, is subjective and, when performed, might involve swabbing or biopsy of several locations. Fluorescence (FL) imaging of bacterial loads is a rapid, non-invasive method to objectively locate microbial hotspots (loads >10⁴ CFU/gr). When sampling is deemed clinically necessary, imaging may indicate an optimal site for tissue biopsy. This study aimed to investigate the microbiology of wound tissue incisional biopsies taken from sites identified by FL imaging compared with sites selected by clinical judgment.

Methods

A post hoc analysis of the 350-patient FLAAG wound trial was conducted; 78 wounds were included in the present study. All 78 wounds were biopsied at two sites: one at the center of the wound per standard of care (SoC) and one site guided by FL-imaging findings, allowing for comparison of total bacterial load (TBL) and species present.

Results

The comparison between the two biopsy sites revealed that clinical uncertainty was higher as wound surface area increased. The sensitivity of a FL-informed biopsy was 98.7% for accurately finding any bacterial loads >10⁴ CFU/g, compared to 87.2% for SoC (p=0.0059; McNemar test). Regarding species detected, FL-informed biopsies detected an average of 3 bacterial species per biopsy versus 2.2 species with SoC (p < 0.001; t-test). Microbial hotspots with a higher number of pathogens also included the CDC's pathogens of interest.

Conclusions & perspective

FL imaging provides a more accurate and relevant microbiological profile that guides optimal wound sampling compared to clinical judgment. This is particularly interesting in large, complex wounds, as evidenced in the wounds studied in this post hoc analysis. In addition, fluorescence imaging enables earlier bacterial detection and intervention, guiding early and appropriate wound hygiene and potentially reducing the need for antibiotic use. When indicated, this diagnostic partnership with antibiotic stewardship initiatives is key to ameliorating the continuing threat of antibiotic resistance.

Tissue healing changes on wounds in rats after treatment with Hancornia speciosa latex in cream-gel formulation

PURPOSE

Hancornia speciosa latex has shown pharmacological potential in wound healing processes due to its angiogenic, osteogenic, and anti-inflammatory activities. The aims of this study were to carry out a cream-gel formulation with 5, 10 and 25% of H. speciosa serum latex and to evaluate its potential to stimulate the skin regeneration in rats' wounds.

METHODS

One hundred and twenty rats were divided into five groups: neutral control with saline (G1), cream-gel based on H. speciosa latex serum at 5% m/v (G2), cream-gel at 15% m/v (G3), cream-gel at 25% m/v (G4), and cream-gel (G5). The animals were euthanized at three, seven, 14 and 21 days after the injury induction, and some parameters were analyzed: wound contraction, necrosis, fibrin, polymorphonuclear and mononuclear infiltrates, fibroblast, angiogenesis, hemorrhage, and collagen.

RESULTS

The therapeutic treatment with cream-gel at 15 and 25% is beneficial in the inflammatory phase of healing processes since it increased the angiogenesis and proliferation of mononuclear infiltrations in wounds. Regarding wound contraction, the treatment with cream-gel (5 and 15%) induced a higher rate of contraction in the proliferative phase. The 15% cream-gel formulation stimulated a greater production of collagen in the injured tissues.

CONCLUSIONS

H. speciosa cream-gel is a low-cost herbal medicine which can aid in tissue repair.

Antibiotic Misuse in Wound Care: Can Bacterial Localization through Fluorescence Imaging Help?

(1) Background: Systemic antibiotic use in chronic wounds is alarmingly high worldwide. Between 53% to 71% of patients are prescribed at least one course per chronic wound. Systemic antibiotic use should follow antibiotic stewardship guidelines and ought to be reserved for situations where their use is deemed supported by clinical indications. Unfortunately, in the field of wound care, indiscriminate and often inadequate use of systemic antibiotics is leading to both patient complications and worsening antibiotic resistance rates. Implementing novel tools that help clinicians prevent misuse or objectively determine the true need for systemic antibiotics is essential to reduce prescribing rates. (2) Methods: We present a compendium of available systemic antibiotic prescription rates in chronic wounds. The impact of various strategies used to improve these rates, as well as preliminary data on the impact of implementing fluorescence imaging technology to finesse wound status diagnosis, are presented. (3) Results: Interventions including feedback from wound care surveillance and treatment data registries as well as better diagnostic strategies can ameliorate antibiotic misuse. (4) Conclusions: Interventions that mitigate unnecessary antibiotic use are needed. Effective strategies include those that raise awareness of antibiotic overprescribing and those that enhance diagnosis of infection, such as fluorescence imaging.

Evaluation of In Vivo Wound-Healing and Anti-Inflammatory Activities of Solvent Fractions of Fruits of Argemone mexicana L. (Papaveraceae)

INTRODUCTION

The solvent fractions of the fruits of Argemone mexicana L. (Papaveraceae) have not yet been explored scientifically for in vivo wound healing and anti-inflammatory activities. The objective of this study was, therefore, to evaluate in vivo wound healing and anti-inflammatory activities of the solvent fractions of the fruit of Argemone mexicana L. (Papaveraceae) in rats.

METHOD

The crude extract of Argemone mexicana was fractionated with n-hexane, ethyl acetate, and distilled water. Wound healing activity was evaluated using excision and incision wound models while anti-inflammatory activity was evaluated using carrageenan-induced rat paw and cotton pellet-induced granuloma models. The fractions were evaluated at 5 and 10% ointments using moist-exposed burn ointment as the standard drug, and 100, 200, and 400 mg/kg test doses using aspirin, and dexamethasone as standard drugs for wound healing and anti-inflammatory activities, respectively. All treatment administrations were made orally for anti-inflammatory activity and applied topically for wound healing activity.

RESULT

The 10% w/w ethyl acetate fraction ointment showed a significant percentage of wound contraction, reduced period of epithelialization, increased amount of fibrosis, neovascularization, and collagen tissue formation (p < 0.01). The ethyl acetate fraction also showed a significant increase in tensile strength (55%; p < 0.01) and (81.10%; p < 0.01) at the tested doses of 5 and 10% w/w ointments, which was comparable to moist-exposed burn ointment. The ethyl acetate fraction also revealed a significant percent edema inhibition (61.41%; p < 0.01), suppression of the exudate (38.09% p < 0.01), and granuloma mass formations (53.47% p < 0.01) at the tested dose of 400 mg/kg.

CONCLUSION

The results of this study showed that the Ethyl acetate fraction of Argemone mexicana fruit has significant wound healing and anti-inflammatory activities which support the traditional claims of the experimental plant.

A Host-Directed Approach to the Detection of Infection in Hard-to-Heal Wounds

Wound infection is traditionally defined primarily by visual clinical signs, and secondarily by microbiological analysis of wound samples. However, these approaches have serious limitations in determining wound infection status, particularly in early phases or complex, chronic, hard-to-heal wounds. Early or predictive patient-derived biomarkers of wound infection would enable more timely and appropriate intervention. The observation that immune activation is one of the earliest responses to pathogen activity suggests that immune markers may indicate wound infection earlier and more reliably than by investigating potential pathogens themselves. One of the earliest immune responses is that of the innate immune cells (neutrophils) that are recruited to sites of infection by signals associated with cell damage. During acute infection, the neutrophils produce oxygen radicals and enzymes that either directly or indirectly destroy invading pathogens. These granular enzymes vary with cell type but include elastase, myeloperoxidase, lysozyme, and cathepsin G. Various clinical studies have demonstrated that collectively, these enzymes, are sensitive and reliable markers of both early-onset phases and established infections. The detection of innate immune cell enzymes in hard-to-heal wounds at point of care offers a new, simple, and effective approach to determining wound infection status and may offer significant advantages over uncertainties associated with clinical judgement, and the questionable value of wound microbiology. Additionally, by facilitating the detection of early wound infection, prompt, local wound hygiene interventions will likely enhance infection resolution and wound healing, reduce the requirement for systemic antibiotic therapy, and support antimicrobial stewardship initiatives in wound care.

Wound healing acceleration and anti-inflammatory potential of Prunella vulgaris L.: From conventional use to preclinical scientific verification

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Prunella L. (Lamiaceae) is represented by nine species in the world and four species in Turkey. The infusion prepared from the aerial parts of Prunella vulgaris L. is used internally for abdominal pain and as an expectorant, the decoction prepared from all parts is used internally or externally as a wound healing.

AIM OF THE STUDY

This study aims to investigate the wound healing potential of Prunella vulgaris L. on the scientific platform.

MATERIAL AND METHODS

The aerial parts of the plant were extracted with 80% methanol. The resulting aqueous methanol extract was partitioned with n-hexane and ethyl acetate, and sub-extracts were obtained. The wound healing effects of the methanol extract and sub-extracts were studied in mice and rats using linear incision and circular excision wound models, and the anti-inflammatory effect was investigated using acetic acid-induced capillary permeability test. Isolation studies were performed using the ethyl acetate sub-extract, which exhibited the highest activity.

RESULTS

Using various chromatographic methods, 6 compounds were isolated from the ethyl acetate sub-extract. The structures of the compounds were identified as methyl arginolate, ursolic acid, chlorogenic acid, rosmarinic acid, methyl 3-epimaclinate, and ethyl rosmarinate by spectroscopic techniques (UV, IR, 13C-NMR, 1H-NMR, 2D-NMR, MS). The wound healing mechanisms of the pure compounds were investigated by performing assays to inhibit the enzymes hyaluronidase, collagenase, and elastase. Ursolic acid, chlorogenic acid, and rosmarinic acid were found to be responsible for the anti-inflammatory and wound healing effects.

CONCLUSION

The experimental study revealed that Prunella vulgaris showed significant wound healing and anti-inflammatory activities.

Biogenic Synthesis of Gold Nanoparticles from Physalis peruviana and Application in Wound Healing

Wound management is key to healing. Poorly managed wounds lead to abnormal biological reactions and complications. Microorganisms, bacteria or fungi, infect such wounds leading to their chronic nature. Gold nanoparticles (Au NPs) show wound healing properties. In addition, ethnobotanical information from Siaya County in Kenya shows the leaves of Physalis peruviana L. to be effective in wound management. A combination of Au NPs and leave extracts of Physalis peruviana L. through a one pot biogenic synthesis leads to a new effective wound management substance. The synthesis was done at room temperature 25°C and at 85°C. The UV-visible spectroscopy results show efficient sharper plasmon bands with a blue shift indicating a decrease in λ max compared to red shift which show an increase in λ max. The surface plasmon resonance is a sharper at wavelength of about 540 nm. Dynamic light scattering and zeta potential analysis show that the polydispersity index is high and this is attributed to heterogeneity of chemical components of the plants. Transmission electron microscopy results for Au NPs show similarity in their shapes and sizes with grain size boundaries of between 1 nm and 100 nm. The particles are spherically shaped and crystalline with small lattice due to the small grains. The gold nanoparticles synthesized from Physalis peruviana show antimicrobial activities against gram-positive bacteria and, gram-negative bacteria as well as gram-positive fungus. The inhibition zones for Au NPs of different concentrations vary significantly between concentrations (one-way ANOVA at $P<0.05$ ). The highest antibacterial activity is at 100 mM of Au NPs against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The inhibition zones for Au NPs at concentration of 100 mM and Physalis peruviana extract vary significantly in all the microbial cells, except for Pseudomonas aeruginosa (one-way ANOVA, F(3,11) = 2.67, $P=0.1189$ ). Application of the Au NPs in wound healing is faster than controls. The Au NPs also have good biocompatibility as signs of infection were not present.

Thermosensitive Hydrogel Wound Dressing Loaded with Bacteriophage Lysin LysP53

Wound infections are prone to attacks from infectious pathogens, including multidrug resistant bacteria that render conventional antimicrobials ineffective. Recently, lysins have been proposed as alternatives to conventional antimicrobials to tackle the menace of multidrug resistance pathogens. The coupling of lysins with a material that will cover the wound may prove beneficial in both protecting and treating wound infections. Hence, in this study, a Gram-negative lysin, LysP53, was coupled with a thermosensitive hydrogel, poloxamer P407, and its efficacy to treat wound infection was tested. In vitro, the addition of LysP53 to the poloxamer did not affect its thermosensitive characteristics, nor did it affect the hydrogel structure. Moreover, the lysin hydrogel could hydrolyze the peptidoglycan, demonstrating that it may have bactericidal activity. Up to 10.4% of LysP53 was released from the hydrogel gradually within 24 h, which led to a 4-log reduction of stationary phase Acinetobacter baumannii. Lastly, the lysin hydrogel was found safe with no cytotoxic effects observed in cells. Ex vivo, LysP53 hydrogel could inhibit bacterial growth on a pig skin decolonization model, with 3-log differences compared to non-treated groups. Overall, our results suggest that lysin-loaded hydrogels may provide a novel solution to treat wound infections caused by resistant bacteria.

Recent Advances in Nano-Formulations for Skin Wound Repair Applications

Skin injuries caused by accidents and acute or chronic diseases place a heavy burden on patients and health care systems. Current treatments mainly depend on preventing infection, debridement, and hemostasis and on supplementing growth factors, but patients will still have scar tissue proliferation or difficulty healing and other problems after treatment. Conventional treatment usually focuses on a single factor or process of wound repair and often ignores the influence of the wound pathological microenvironment on the final healing effect. Therefore, it is of substantial research value to develop multifunctional therapeutic methods that can actively regulate the wound microenvironment and reduce the oxidative stress level at the wound site to promote the repair of skin wounds. In recent years, various bioactive nanomaterials have shown great potential in tissue repair and regeneration due to their properties, including their unique surface interface effect, small size effect, enzyme activity and quantum effect. This review summarizes the mechanisms underlying skin wound repair and the defects in traditional treatment methods. We focus on analyzing the advantages of different types of nanomaterials and comment on their toxicity and side effects when used for skin wound repair.

A hemostatic keratin/alginate hydrogel scaffold with methylene blue mediated antimicrobial photodynamic therapy

Uncontrollable bleeding and infection are two of the most common causes of trauma-related death. Yet, developing safe materials with high hemostatic and antibacterial effectiveness remains a challenge. Keratin-based biomaterials have been reported to exhibit the functions of enhancing platelet binding and activating and facilitating fibrinogen polymerization. In this study, we designed a hemostatic material with good biodegradability, biocompatibility, hemostatic ability, and antibacterial function to solve the shortcomings of common hemostatic materials. Methylene blue-loaded keratin/alginate composite scaffolds were prepared by the freeze-gelation method. The composite scaffolds exhibited over 1600% liquid absorption, well-interconnected pores, good biocompatibility, and biodegradability. We find that the keratin/alginate composite scaffolds' synergistic action may significantly reduce hemostasis time. To prevent infection, the drug-loaded scaffolds generated high burst release by absorbing wound exudate in the early stages of wound healing. The results obtained by the antimicrobial photoinactivation assay in vitro suggest that an antimicrobial photodynamic effect might be triggered, thereby preventing the fast growth of colonies.

Filamentous bacteriophage delays healing of Pseudomonas-infected wounds

Chronic wounds infected by Pseudomonas aeruginosa (Pa) are characterized by disease progression and increased mortality. We reveal Pf, a bacteriophage produced by Pa that delays healing of chronically infected wounds in human subjects and animal models of disease. Interestingly, impairment of wound closure by Pf is independent of its effects on Pa pathogenesis. Rather, Pf impedes keratinocyte migration, which is essential for wound healing, through direct inhibition of CXCL1 signaling. In support of these findings, a prospective cohort study of 36 human patients with chronic Pa wound infections reveals that wounds infected with Pf-positive strains of Pa are more likely to progress in size compared with wounds infected with Pf-negative strains. Together, these data implicate Pf phage in the delayed wound healing associated with Pa infection through direct manipulation of mammalian cells. These findings suggest Pf may have potential as a biomarker and therapeutic target in chronic wounds.

Functionalized injectable hyaluronic acid hydrogel with antioxidative and photothermal antibacterial activity for infected wound healing

Infected wound healing has always been a challenge in clinic. Effective and economic wound dressings with combined antibacterial activity and pro-healing function are highly desirable, especially in the context of infected wounds. An obvious advantage of antibacterial wound dressing is to avoid the overuse of antibiotics and the occurrence of drug resistance. Herein, an injectable hyaluronic acid hydrogel with antioxidative and photothermal antibacterial activity as a functional dressing was prepared, characterized and evaluated in an experimental infected wound model. This hydrogel was developed by loading graphene oxide (GO) in a natural polymer network consisting of hyaluronic acid grafted with tyramine (HT) and gelatin grafted with gallic acid (GGA). The HT/GGA/GO hydrogels have a porous cross-linked network structure and demonstrate a good stability, biocompatibility, antioxidant, hemostatic and photothermal antibacterial activity against Escherichia coli and Staphylococcus aureus. In addition, in vivo studies have shown that HT₁/GGA₂/GO_0.1 hydrogel dressing combined with photothermal therapy can effectively prevent early infection and accelerate wound healing. These results indicated this functionalized injectable hydrogel HT₁/GGA₂/GO_0.1 has a great potential in wound dressing application.

Antibacterial peptide NZ2114-loaded hydrogel accelerates Staphylococcus aureus-infected wound healing

Wound infection caused by Staphylococcus aureus (S. aureus) is a great challenge which has caused significant burden and economic loss to the medical system. NZ2114, a plectasin-derived peptide, is an antibacterial agent for preventing and treating S. aureus infection, especially for methicillin-resistant S. aureus (MRSA) infection. Here, three-dimensional reticulated antimicrobial peptide (AMP) NZ2114 hydrogels were developed based on hydroxypropyl cellulose (HPC) and sodium alginate (SA); they displayed sustained and stable release properties (97.88 ± 1.79% and 91.1 ± 10.52% release rate in 72 h, respectively) and good short-term cytocompatibility and hemocompatibility. But the HPC-NZ2114 hydrogel had a smaller pore size (diameter 0.832 ± 0.420 μm vs. 3.912 ± 2.881 μm) and better mechanical properties than that of the SA-NZ2114 hydrogel. HPC/SA-NZ2114 hydrogels possess efficient antimicrobial activity in vitro and in vivo. In a full-thickness skin defect model, the wound closure of the 1.024 mg/g HPC-NZ2114 hydrogel group was superior to those of the SA-NZ2114 hydrogel and antibiotic groups on day 7. The HPC-NZ2114 hydrogel accelerated wound healing by reducing inflammation and promoting the production of vascular endothelial growth factor (VEGF), endothelial growth factor (EGF) and angiogenesis (CD31) through histological and immunohistochemistry evaluation. These data indicated that the HPC-NZ2114 hydrogel is an excellent candidate for S. aureus infection wound dressing. KEY POINTS: •NZ2114 hydrogels showed potential in vitro bactericidal activity against S. aureus •NZ2114 hydrogels could release continuously for 72 h and had good biocompatibility •NZ2114 hydrogels could effectively promote S. aureus-infected wound healing.

Aloe vera and Streptozotocin-Induced Diabetes Mellitus

Diabetes mellitus is defined as prolonged hyperglycemia, which can harm the eyes, kidneys, and cardiovascular and neurological systems. Herbal agents and their derived supplements have been used for treatment of diabetes mellitus as a part of integrated complementary medicine for centuries. Numerous studies have considered Aloe vera (L.) Burm.f, Xanthorrhoeaceae, as an alternative medicine due to its abundant bioactive chemicals, such as alkaloids, anthraquinones, and enthrones, with therapeutical properties including antioxidant, anti-inflammatory, neuro-protective, and anti-diabetic effects. Aloe vera has received considerable attention in traditional medicine for the treatment of several diseases including diabetes mellitus. Numerous studies have investigated the effects of herbal agents on diabetes mellitus using a streptozotocin-induced diabetic model. Thereby, this article reviews the effects of Aloe vera prescription on streptozotocin-induced diabetes mellitus to provide a clear insight into the role of this medicinal plant in several biological functions, such as antioxidant, wound healing, anti-inflammatory, anti-hyperglycemic, and anti-hyperlipidemic in diabetic models.

Effect of Modified Allgöwer-Donati Suture Technique on Wound Cosmetics in Spinal Surgery

Objective

To analyze the efficacy of modified Allgöwer–Donati suture (MADS) technique on cosmetic outcomes compared with vertical mattress suture (VMS) technique in spinal surgery wounds.

Methods

This randomized controlled trial was conducted at the First Hospital of Lanzhou University (Gansu, China) from September 2019 to August 2020. The patients were randomly divided into two groups, a VMS group and a MADS group, by staff not involved in the treatment using a computer‐based random number table program (no restrictions on age or sex). Both procedures were performed by the same group of physicians as well as assistants. All suture wounds were completed by the same person. The primary endpoint was the scar area, and the postoperative scar area was scored by the Patient and Observer Scar Scale Assessment (POSAS). The scar area was calculated by ImageJ software. The second outcome measure was wound complications, including poor wound healing, wound edge necrosis, and infection. The trial was recorded in the Chinese Clinical Trial Register on 18 August 2019 (ChiCTR1900024548).

Results

A total of 143 patients were included: 72 in the VMS group and 71 in the MADS group. There was no significant difference in their demographics in terms of age (49.71 ± 8.91 vs 50.15 ± 6.79 years, P = 0.737), sex (M/F, 30/41 vs 31/41, P = 0.923), suture time (3.39 ± 0.22 vs 3.47 ± 0.25 s/mm, P = 0.057), or body mass index (BMI, 23.88 ± 3.50 vs 24.05 ± 3.50, P = 0.765) for MADS to VMS. The postoperative scar area was compared between the two groups transversely on day 12, the MADS wound scars decreased by 58.95% (75,133.24/127,452.58). In the POSAS evaluation, after MADS treatment, surface area score decreased from 5 (4, 5) to 2 (2, 3) (P < 0.0001), observer's overall opinion from 5 (4, 5) to 3 (2, 3) (P < 0.0001), itching from 3 (3, 4) to 3 (2, 3) (P = 0.001), color from 4 (4, 5) to 3 (2–4) (P < 0.0001), stiffness 4 (3–4.75) to 3 (3, 4) (P < 0.0001), or thickness from 4 (3–5) to 4 (3, 4) (P = 0.004). In terms of overall opinion evaluation, the MADS showed a significant difference in observer's overall opinion to the VMS (5 (4, 5) vs 3 (2, 3), P < 0.0001) and in patient's overall opinion 5 (5, 6) to 3 (3, 4), (P < 0.0001). There was no significant statistical difference in poor wound healing (3 vs 0, P = 0.245), wound edge necrosis (3 vs 0, P = 0.245), and infection (1 vs 0, P = 1.000) with the MADS to the VMS.

Conclusion

The results of this study show that the MADS effectively reduced the surgical scar area to 58.95% with no additional adverse events compared with that of the VMS in spine surgery.

Protein-Based Systems for Topical Antibacterial Therapy

Recently, proteins are gaining attention as potential materials for antibacterial therapy. Proteins possess beneficial properties such as biocompatibility, biodegradability, low immunogenic response, ability to control drug release, and can act as protein-mimics in wound healing. Different plant- and animal-derived proteins can be developed into formulations (films, hydrogels, scaffolds, mats) for topical antibacterial therapy. The application areas for topical antibacterial therapy can be wide including bacterial infections in the skin (e.g., acne, wounds), eyelids, mouth, lips, etc. One of the major challenges of the healthcare system is chronic wound infections. Conventional treatment strategies for topical antibacterial therapy of infected wounds are inadequate, and the development of newer and optimized formulations is warranted. Therefore, this review focuses on recent advances in protein-based systems for topical antibacterial therapy in infected wounds. The opportunities and challenges of such protein-based systems along with their future prospects are discussed.

Chitosan-based multifunctional hydrogel containing in-situ rapidly bioreduced silver nanoparticles for accelerating infected wound healing

Generally, bacterial infection seriously hinders the wound healing process, so it is crucial to safeguard the wound from severe infection. Besides, multifunctional hydrogel dressings (self-healing, injectable, antibacterial and adaptable) seem...

Growth factors, as biological macromolecules in bioactivity enhancing of electrospun wound dressings for diabetic wound healing: A review

Impaired wound healing is of the most conspicuous characteristics of diabetic mellitus. Reduced blood flow, chronic inflammatory reactions, infection, endothelial dysfunction, elevated levels of reactive oxygen species, and metabolic disorders cause wounds to heal more slowly in these patients. Previous studies have reported useful impacts of growth factors in management of such wounds. However, due to their short half-life and low stability, a suitable delivery platform with sustained release profile may boost their healing potential. Controlled and localized delivery of growth factors via electrospun fibers have been extensively explored in previous studies. The electrospinning method; although not new, has turned out to be extremely effective for the preparation of delivery carriers for growth factors. Due to their structural resemblance to native tissues' extracellular matrix, high encapsulation efficacy, tunability, and high surface to volume ratio, electrospun scaffolds have gained significant attention in drug delivery and tissue engineering. In the current review, careful integration of current research regarding the applications of growth factors' delivery through electrospun fibers in diabetic wounds healing has been done. This review will not only give an insight into the current updates, but will also highlights the future perspectives and challenges.

Multifunctional Antibiotic-Host Defense Peptide Conjugate Kills Bacteria, Eradicates Biofilms, and Modulates the Innate Immune Response

Effective anti-infective therapies are required to offset the rise in antibiotic resistance. A novel vancomycin-innate defense regulator conjugate (V-IDR1018) was constructed with multimodal functionality, including bacterial killing, biofilm eradication, and immune modulation. The conjugate killed bacteria within 30 min, exhibited potent activity against persister cells, and showed no susceptibility to antimicrobial resistance in tissue culture assays. Additionally, it stimulated the release of chemokine MCP-1 and anti-inflammatory cytokine IL-10 and suppressed pro-inflammatory IL-1β from lipopolysaccharide-stimulated white blood cells. The conjugate demonstrated ∼90% eradication efficacy when assessed against the MRSA biofilm formed on an organoid human skin equivalent. Similarly, when evaluated in a murine, high-density skin abscess infection model using MRSA or Staphylococcus epidermidis, the conjugate decreased dermonecrosis and reduced bacterial load. The exceptional in vitro and in vivo efficacy of the conjugate, in addition to its safety profile, makes it a valuable candidate to treat complex infectious diseases.

Effect on healing rates of wounds treated with direct cold atmospheric plasma: a case series

OBJECTIVE

The response of different critical acute and hard-to-heal wounds to an innovative wound care modality-direct application of cold atmospheric plasma (CAP)-was investigated in this clinical case series.

METHOD

Over an observation period of two years, acute wounds with at least one risk factor for chronification, as well as hard-to-heal wounds were treated for 180 seconds three times per week with CAP. CAP treatment was additional to standard wound care. Photographs were taken for wound documentation. The wound sizes before the first CAP treatment, after four weeks, after 12 weeks and at wound closure/end of observation time were determined using image processing software, and analysed longitudinally for the development of wound size.

RESULTS

A total of 27 wounds (19 hard-to-heal and eight acute wounds) with a mean wound area of 15cm² and a mean wound age of 49 months were treated with CAP and analysed. All (100%) of the acute wounds and 68% of the hard-to-heal wounds healed after an average treatment duration of 14.2 weeks. At the end of the observation period, 21% of hard-to-heal wounds were not yet closed but were reduced in size by >80%. In 11% of the hard-to-heal wounds (n=2) therapy failed.

CONCLUSION

The results suggested a beneficial effect of additional CAP therapy on wound healing.

DECLARATION OF INTEREST

This work was carried out within the research projects 'Plasma for Life' (funding reference no. 13FH6I04IA) with financial support from the German Federal Ministry of Education and Research (BMBF). In the past seven years AFS has provided consulting services to Evonik and has received institutional support by Heraeus, Johnson & Johnson and Evonik. There are no royalties to disclose. The Department for Trauma Surgery, Orthopaedics and Plastic Surgery received charitable donations by CINOGY GmbH. CINOGY GmbH released the di_CAP devices and electrodes for the study. WV and AH were involved in the development of the used di_CAP device (Plasmaderm, CINOGY GmbH). WV is shareholder of the outsourced start-up company CINOGY GmbH.

Healing of disrupted perineal wounds after vaginal delivery: a poorly understood condition

Perineal injury following childbirth can result in complications such as wound infection and dehiscence. The reported incidence of these complications in the literature range between 0.1-23.6% and 0.2-24.6%, respectively. However, the healing of disrupted perineal wounds is poorly understood. In addition, it is a neglected area in maternity services. In this review, the authors explore the process of wound healing in the context of infected perineal wounds following childbirth. In addition, the authors describe the management of complications including hypergranulation, perineal pain and dyspareunia.

Stereological and molecular studies on the effects of Ferula persica extract on wound healing in rats

Background

Ferula persica is one of the most important traditional medicinal plants that is used to treat various diseases such as diabetes, backache and rheumatism. The aim of the present study was to evaluate the anti‐inflammatory and wound healing potential of F. persica using stereological and molecular methods in experimental models.

Methods

In the present study, two wound models (circular excision and linear incision) were used. Male Wistar rats were divided into four groups (n = 16), including control, vehicle treated, treated with F. persica extract ointment (5% w/w) and treated with the reference drug (Madecassol). All the animals were treated topically once a day. The circular and linear wounds were treated for 9 and 17 days, respectively. At the end of the study, samples from wounds area were harvested for histology, stereology, immunohistochemistry and molecular assessments to determine the in vivo healing potential and anti‐inflammatory activity.

Results

We observed significant recovery in macroscopic evaluation of wound healing in the F. persica extract treated group compared with the control and vehicle treated groups (p < 0.05). Histological and stereological assessments showed complete repair of the epidermal layer, increasing fibroblast cells and collagen density, decreasing inflammatory cells and a remarkable degree of neovascularization by determining length density of blood vessels in the extract group, which were significant as compared to the control and vehicle treated groups (p < 0.05). Expressions of TNF‐α and TGF‐β were found to be decreased and increased (p > 0.05, p < 0.05, respectively), in the extract treated group as compared to the control and vehicle treated groups. Also, greater COX‐2 expression could be detected in the control and vehicle treated groups, which was significantly attenuated in the extract group.

Conclusion

Our results confirm that the F. persica extract is a valuable source of antioxidant and anti‐inflammatory activity and can allow damaged tissue in wounds to recover markedly.

Autologous platelet-rich fibrin (PRF) augmentation as an add-on therapy in deep surgical site infections (dSSIs) after instrumented spinal surgery: preliminary results of a single institution case series

BACKGROUND

Deep surgical site infections (dSSIs) after instrumented spinal surgery pose major therapeutic challenges. Standard treatment involves surgical debridement, wound drainage, and long-term antibiotic administration. Autologous platelet-rich fibrin (PRF) constitutes a biomaterial obtained from patients' own blood that contains leukocytes, chemokines and growth factors boosting cicatrization. Due to favorable results reported from other surgical disciplines such as dentistry, orthopedics, maxillofacial and plastic surgery using PRF, the authors hypothesized that PRF augmentation will promote wound healing in dSSIs.

OBJECTIVE

To report our preliminary results on the safety and efficacy of autologous-PRF as an add-on therapy on a pilot case series of persistent dSSI after instrumented spinal surgery.

METHODS

Among the 293 patients who underwent dorsal decompression and stabilization of the cervical, thoracic, and lumbar spine due to degenerative diseases in our department, 12 patients (4%) presented persisting dSSI after standard wound debridement and antibiotic treatment. PRF augmentation was used during a second surgical revision as an add-on therapy to standard debridement. In all cases, the wound was primarily closed without drains.

RESULTS

Wound healing was completed between 14 and 21 days after the second surgical revision in all patients. At a median follow-up of 8 months (range: 6 to 18 months), no recurrence of dSSI nor complications were encountered in any case.

CONCLUSIONS

Our preliminary results suggest that PRF augmentation in persistent dSSI after instrumented spinal surgery appears to be a safe and effective strategy to promote wound healing. Prospective controlled studies are required to define the efficiency of PRF more clearly in both treating and preventing dSSI.

Detection of bacterial fluorescence from in vivo wound biofilms using a point-of-care fluorescence imaging device

Wound biofilms must be identified to target disruption and bacterial eradication but are challenging to detect with standard clinical assessment. This study tested whether bacterial fluorescence imaging could detect porphyrin-producing bacteria within a biofilm using well-established in vivo models. Mouse wounds were inoculated on Day 0 with planktonic bacteria (n = 39, porphyrin-producing and non-porphyrin-producing species, 107  colony forming units (CFU)/wound) or with polymicrobial biofilms (n = 16, 3 biofilms per mouse, each with 1:1:1 parts Staphylococcus aureus/Escherichia coli/Enterobacter cloacae, 107  CFU/biofilm) that were grown in vitro. Mouse wounds inoculated with biofilm underwent fluorescence imaging up to Day 4 or 5. Wounds were then excised and sent for microbiological analysis. Bacteria-matrix interaction was assessed with scanning electron microscopy (SEM) and histopathology. A total of 48 hours after inoculation with planktonic bacteria or biofilm, red fluorescence was readily detected in wounds; red fluorescence intensified up to Day 4. Red fluorescence from biofilms persisted in excised wound tissue post-wash. SEM and histopathology confirmed bacteria-matrix interaction. This pre-clinical study is the first to demonstrate the fluorescence detection of bacterial biofilm in vivo using a point-of-care wound imaging device. These findings have implications for clinicians targeting biofilm and may facilitate improved visualisation and removal of biofilms.

Medical gas plasma-stimulated wound healing: Evidence and mechanisms

Defective wound healing poses a significant burden on patients and healthcare systems. In recent years, a novel reactive oxygen and nitrogen species (ROS/RNS) based therapy has received considerable attention among dermatologists for targeting chronic wounds. The multifaceted ROS/RNS are generated using gas plasma technology, a partially ionized gas operated at body temperature. This review integrates preclinical and clinical evidence into a set of working hypotheses mainly based on redox processes aiding in elucidating the mechanisms of action and optimizing gas plasmas for therapeutic purposes. These hypotheses include increased wound tissue oxygenation and vascularization, amplified apoptosis of senescent cells, redox signaling, and augmented microbial inactivation. Instead of a dominant role of a single effector, it is proposed that all mechanisms act in concert in gas plasma-stimulated healing, rationalizing the use of this technology in therapy-resistant wounds. Finally, addressable current challenges and future concepts are outlined, which may further promote the clinical utilization, efficacy, and safety of gas plasma technology in wound care in the future.

Integrated Multiplex Sensing Bandage for In Situ Monitoring of Early Infected Wounds

Infection, the most common complication of chronic wounds, has placed tremendous burden on patients and society. Existing care strategies could hardly reflect in situ wound status, resulting in overly aggressive or conservative therapeutic options. Multiplexed tracking of wound markers to obtain diagnostic information in a more accurate way is highly promising and in great demand for the emerging development of personalized medicine. Here, an integrated multiplex sensing bandage (MSB) system, including a multiplex sensor array (MSA), a corresponding flexible circuit, and a mobile application, was developed for real-time monitoring of sodium, potassium, calcium, pH, uric acid, and temperature indicators in the wound site to provide a quantitative diagnostic basis. The MSB was optimized for wound-oriented management applications, which exhibits a broad linear response, excellent selectivity, temporal stability, mechanical stability, reproducibility, and reliable signal transmission performance on the aforementioned physiological indicators. The results of in vivo experiments demonstrate that the MSA is capable of real-time monitoring of actual wounds as well as early prediction of infection. The results ultimately point to the potential clinical applicability of the MSB, which might benefit the quantifications of the complexity and diversity of the wound healing process. This work provides a unique strategy that holds promise for broad application in optimizing wound management and even coping with other diseases.

Hard-to-heal wound treated with Integra Flowable Wound Matrix: analysis and clinical observations

Skin healing defects severely impair the quality of life of millions of people and burden healthcare systems globally. The therapeutic approach to these pathologies still represents a challenge. Novel scaffolds, used as dermal substitutes, possibly represent a promising strategy in complex wound management. Integra Flowable Wound Matrix (IFWM) is composed of a lyophilised, micronised form of collagen/chondroitin sulphate matrix, already used in regenerative medicine and endorsed in the therapy of diabetic foot lesions. In this paper, IFWM was applied to a tunnelling hard-to-heal skin lesion in order to restore tissue integrity. Although the different phases of skin wound healing are well established, the molecular mechanism underpinning IFWM-induced tissue repair are almost unknown. Here, we report, for the first time, the comparative analysis of molecular, histological and clinical observations of the healing process of a hard-to-heal tunnelling skin wound. The therapeutic success of this clinical case allowed us to recommend the use of IFWM as a tissue substitute in this rare type of hard-to-heal wound in which the high inflammatory status hampered the natural healing process.

Preparation and Application of Quaternized Chitosan- and AgNPs-Base Synergistic Antibacterial Hydrogel for Burn Wound Healing

Infection is the major reason that people die from burns; however, traditional medical dressings such as gauze cannot restrain bacterial growth and enhance the healing process. Herein, an organic- and inorganic-base hydrogel with antibacterial activities was designed and prepared to treat burn wounds. Oxidized dextran (ODex) and adipic dihydrazide grafted hyaluronic acid (HA-ADH) were prepared, mixed with quaternized chitosan (HACC) and silver nanoparticles to fabricate Ag@ODex/HA-ADH/HACC hydrogel. The hydrogel, composed of nature biomaterials, has a good cytocompatibility and biodegradability. Moreover, the hydrogel has an excellent antibacterial ability and presents fast healing for burn wounds compared with commercial Ag dressings. The Ag@ODex/HA-ADH/HACC hydrogel will be a promising wound dressing to repair burn wounds and will significantly decrease the possibility of bacterial infection.

Dopamine-Substituted Multidomain Peptide Hydrogel with Inherent Antimicrobial Activity and Antioxidant Capability for Infected Wound Healing

Wound infection can cause a delay in wound healing or even wound deterioration, threatening patients' lives. The excessive accumulation of reactive oxygen species (ROS) in infected wounds activates a strong inflammatory response to delay wound healing. Therefore, it is highly desired to develop hydrogels with inherent antimicrobial activity and antioxidant capability for infected wound healing. Herein, a dopamine-substituted multidomain peptide (DAP) with inherent antimicrobial activity, strong skin adhesion, and ROS scavenging has been developed. DAP can form bilayer β-sheets with dopamine residues on the surface of nanofibers. The enhanced rheological properties of DAP-based hydrogel can be achieved not only through UV irradiation but also by incorporation of multivalent ions (e.g., PO₄^3-). Furthermore, the DAP hydrogel shows a broad spectrum of antimicrobial activity due to the high positive charges of lysine residues and the β-sheet formation. When applied to full-thickness dermal wounds in mice, the DAP hydrogel results in a significantly shortened inflammatory stage of the healing process because of its remarkable antimicrobial activity and antioxidant capability. Accelerated wound closure with thick granulation tissue, uniform collagen arrangement, and dense vascularization can be achieved. This work suggests that the DAP hydrogel can serve as antimicrobial coating and ROS-scavenging wound dressing for bacterial-infected wound treatment.

Investigation of Wound Healing and Anti-Inflammatory Activities of Solvent Fractions of 80% Methanol Leaf Extract of Achyranthes aspera L. (Amaranthaceae) in Rats

INTRODUCTION

The various fractions of leaves of Achyranthes aspera L. (A. aspera) have not yet been explored scientifically for in-vivo wound healing and anti-inflammatory activities. The objective of this study was, therefore, to evaluate in-vivo wound healing and anti-inflammatory activities of solvent fractions of 80% methanol leaf extract of A. aspera in rats.

METHODS

The 80% methanol leaf extract of A. aspera was fractionated with chloroform, n-butanol and water. Wound healing and anti-inflammatory activities were evaluated using excision and incision wound models, rat paw edema and cotton pellet-induced granuloma models, respectively. For wound healing activity, fractions were evaluated at 5 and 10% ointments. The positive control groups were treated with nitrofurazone 0.2% ointment. Simple ointment treated for excision wound model and untreated for incision wound model rats were assigned as negative controls. For anti-inflammatory activity, fractions were evaluated at 100, 200 and 400mg/kg. Positive control groups were treated with indomethacin 10mg/kg for both rat paw edema and cotton pellet-induced granuloma models. The 2% Tween 80 treated rats were assigned as negative controls for both anti-inflammatory activity models. All groups comprised of 6 rats and treatment administrations were made topically and orally for evaluation of wound healing and anti-inflammatory activities.

RESULTS

The 10% w/w chloroform fraction ointment revealed a high percentage of wound contraction and reduced period of epithelialization (p <0.01). Chloroform fraction was also found to be the most active fraction, which demonstrated the maximum percentage inhibition of edema (52.50%; p <0.01) and transudative and proliferative component of chronic inflammation (37.52 and 52.81%; p <0.01), which was comparable to indomethacin.

CONCLUSION

Data obtained from this study collectively indicated that a chloroform fraction of 80% methanol leaf extract of A. aspera possessed significant wound healing and anti-inflammatory activities.

Diagnostic Accuracy of Point-of-Care Fluorescence Imaging for the Detection of Bacterial Burden in Wounds: Results from the 350-Patient Fluorescence Imaging Assessment and Guidance Trial

Objective: High bacterial load contributes to chronicity of wounds and is diagnosed based on assessment of clinical signs and symptoms (CSS) of infection, but these characteristics are poor predictors of bacterial burden. Point-of-care fluorescence imaging (FL) MolecuLight i:X can improve identification of wounds with high bacterial burden (>10⁴ colony-forming unit [CFU]/g). FL detects bacteria, whether planktonic or in biofilm, but does not distinguish between the two. In this study, diagnostic accuracy of FL was compared to CSS during routine wound assessment. Postassessment, clinicians were surveyed to assess impact of FL on treatment plan. Approach: A prospective multicenter controlled study was conducted by 20 study clinicians from 14 outpatient advanced wound care centers across the United States. Wounds underwent assessment for CSS followed by FL. Biopsies were collected to confirm total bacterial load. Three hundred fifty patients completed the study (138 diabetic foot ulcers, 106 venous leg ulcers, 60 surgical sites, 22 pressure ulcers, and 24 others). Results: Around 287/350 wounds (82%) had bacterial loads >10⁴ CFU/g, and CSS missed detection of 85% of these wounds. FL significantly increased detection of bacteria (>10⁴ CFU/g) by fourfold, and this was consistent across wound types (p < 0.001). Specificity of CSS+FL remained comparably high to CSS (p = 1.0). FL information modified treatment plans (69% of wounds), influenced wound bed preparation (85%), and improved overall patient care (90%) as reported by study clinicians. Innovation: This novel noncontact, handheld FL device provides immediate, objective information on presence, location, and load of bacteria at point of care. Conclusion: Use of FL facilitates adherence to clinical guidelines recommending prompt detection and removal of bacterial burden to reduce wound infection and facilitate healing.