Challenges in the diagnosis and management of wound infection

Novel Hydrogel Adjuvant of Chinese Medicine External Preparations for Accelerated Healing of Deep Soft Tissue Injuries

Traditional Chinese medicine external prescriptions have displayed excellent clinical effects for treating deep soft tissue injuries. However, the effects cannot be fully utilized due to the limitations of their dosage forms and usage methods. It is still a challenge to develop a satisfactory adjuvant of traditional Chinese medicine external prescriptions. Herein, a hydrogel adjuvant was prepared based on gallic acid coupled ε-poly-l-lysine and partially oxidized hyaluronic acid. The resulting adjuvant shows great physicochemical properties, low hemolysis rate (still much less than 5% at 5 mg/mL), excellent antibacterial ability (about 95% at 2 mg/mL), strong antioxidant ability (1.687 ± 0.085 mmol FeSO4/(g hydrogel) at 1 mg/mL), as well as outstanding biocompatibility. A clinically used Chinese medicine external preparation was selected as an example to investigate the effectiveness of the adjuvant in treating deep soft tissue injuries. The results show that the prescription can be evenly dispersed in the adjuvant. Moreover, the introduction of the prescription has not significantly changed these advanced properties of the adjuvant. Importantly, the hydrogel adjuvant significantly improves the effectiveness of the prescription in treating deep soft tissue injuries. This work offers an alternative approach to the development of a new-type adjuvant of Chinese medicine external preparations and also provides a new strategy for the combination of traditional Chinese medicine and hydrogel to treat clinical diseases.

Transformation of Natural Resin Resina Draconis to 3D Functionalized Fibrous Scaffolds for Efficient Chronic Wound Healing

Chronic wound healing is a major challenge in clinical practice. Secondary dressing damage and antibiotic resistance are the main obstacles for traditional wound dressings. Resina draconis (RD), a natural resin traditionally used in powder form for wound care, is now considered unsuitable due to the lack of gas permeability and moist environment required for wound healing. Here, RD is incorporated in situ by constructing a 3D coiled fibrous scaffold with polycaprolactone/polyethylene oxide. Due to the high porosity of 3D scaffold, the RD-3D dressings have a favorable swelling capacity, providing permeability and moisture for wound repair. Meanwhile, the transformation of RD powder into 3D dressings fully demonstrates capabilities of RD in rapid hemostasis, bactericidal, and inflammation-regulating activities. In vivo evaluations using pressure ulcer and infected wound models confirm the high efficacy of RD-3D dressing in early wound healing, particularly beneficial in the infected wound model compared to recombinant bovine FGF-basic. Further biological analysis shows that resveratrol, loureirin A, and loureirin B, as potentially bioactive components of RD, individually contribute to different aspects of wound healing. Collectively, RD-3D integrated dressings represent a simple, cost-effective, and safe approach to wound healing, providing an alternative therapy for translating medical dressings from bench to bedside.

Design and Application of an In Situ Traceable Nitric Oxide Donor for Promoting the Healing of Wound Infections

Therapies for wound infections require medications with antibacterial and wound-healing functions. However, it remains a challenge to produce a single drug that can perform dual functions. Nitric oxide (NO), with its antibacterial and wound-healing activities, is an ideal solution to address this challenge. However, many controlled-release strategies for NO rely on external probes for tracing the release in situ, making it difficult to precisely assess the location and magnitude. To address this issue, this study describes a novel NO donor, DHU-NO1, capable of efficiently releasing NO under mild conditions (450 nm illumination). Simultaneously, DHU-NO1 generates the fluorophore Azure B (AZB), which enables direct, non-consumptive tracing of the NO release by monitoring the fluorescence and absorption changes in AZB. Given that NO can be conveniently traced, the amount of released NO can be controlled during biological applications, thereby allowing both functions of NO to be performed. When applied to the affected area, DHU-NO1, illuminated by both a simple light-emitting diode (LED) light source and natural light, achieves significant antibacterial effects against wound infections and promotes wound healing in mice. This study offers a novel and effective approach for treating wound infections.

Current Knowledge and Perspectives of Phage Therapy for Combating Refractory Wound Infections

Wound infection is one of the most important factors affecting wound healing, so its effective control is critical to promote the process of wound healing. However, with the increasing prevalence of multi-drug-resistant (MDR) bacterial strains, the prevention and treatment of wound infections are now more challenging, imposing heavy medical and financial burdens on patients. Furthermore, the diminishing effectiveness of conventional antimicrobials and the declining research on new antibiotics necessitate the urgent exploration of alternative treatments for wound infections. Recently, phage therapy has been revitalized as a promising strategy to address the challenges posed by bacterial infections in the era of antibiotic resistance. The use of phage therapy in treating infectious diseases has demonstrated positive results. This review provides an overview of the mechanisms, characteristics, and delivery methods of phage therapy for combating pathogenic bacteria. Then, we focus on the clinical application of various phage therapies in managing refractory wound infections, such as diabetic foot infections, as well as traumatic, surgical, and burn wound infections. Additionally, an analysis of the potential obstacles and challenges of phage therapy in clinical practice is presented, along with corresponding strategies for addressing these issues. This review serves to enhance our understanding of phage therapy and provides innovative avenues for addressing refractory infections in wound healing.

Effective antibacterial agents in modern wound dressings: a review

Wound infections are a significant concern in healthcare, leading to long healing times. Traditional approaches for managing wound infections rely heavily on systemic antibiotics, which are associated with the emergence of antibiotic-resistant bacteria. Therefore, the development of alternative antibacterial materials for wound care has gained considerable attention. In today's world, new generations of wound dressing are commonly used to heal wounds. These new dressings keep the wound and the area around it moist to improve wound healing. However, this moist environment can also foster an environment that is favorable for the growth of bacteria. Excessive antibiotic use poses a significant threat to human health and causes bacterial resistance, so new-generation wound dressings must be designed and developed to reduce the risk of infection. Wound dressings using antimicrobial compounds minimize wound bacterial colonization, making them the best way to avoid open wound infection. We aim to provide readers with a comprehensive understanding of the latest advancements in antibacterial materials for wound management.

M.O.I.S.T. Concept for the Local Therapy of Chronic Wounds: An International Update

Chronic wounds remain a significant clinical challenge both for those affected and for healthcare systems. The treatment is often comprised and complex. All patients should receive wound care that is integrated into a holistic approach involving local management that addresses the underlying etiology and provides for gold standard therapy to support healing, avoid complications and be more cost effective. There have been significant advances in medicine over the last few decades. The development of new technologies and therapeutics for the local treatment of wounds is also constantly increasing. To help standardize clinical practice with regard to the multitude of wound products, the M.O.I.S.T. concept was developed by a multidisciplinary expert group. The M stands for moisture balance, O for oxygen balance, I for infection control, S for supporting strategies, and T for tissue management. Since the M.O.I.S.T. concept, which originated in the German-speaking countries, is now intended to provide healthcare professionals with an adapted instrument to be used in clinical practice, and a recent update to the concept has been undertaken by a group of interdisciplinary experts to align it with international standards. The M.O.I.S.T. concept can now be used internationally both as an educational tool and for the practical implementation of modern local treatment concepts for patients with chronic wounds and can also be used in routine clinical practice.

The transformation of multifunctional bio-patch to hydrogel on skin wounds for efficient scarless wound healing

Hydrogels have been widely used in various biomedical applications, including skin regeneration and tissue repair. However, the capability of certain hydrogels to absorb exudate or blood from surrounding wounds, coupled with the challenge in their long-term storage to prevent bacterial growth, can pose limitations to their efficacy in biological applications. To address these challenges, the development of a multifunctional aloin-arginine-alginate (short for 3A) bio-patch capable of transforming into a hydrogel upon absorbing exudate or blood from neighboring wounds for cutaneous regeneration is proposed. The 3A bio-patch exhibits outstanding features, including an excellent porous structure, swelling properties, and biodegradability. These characteristics allow for the rapid absorption of wound exudates and subsequent transformation into a hydrogel that is suitable for treating skin wounds. Furthermore, the 3A bio-patch exhibits remarkable antibacterial and anti-inflammatory properties, leading to accelerated wound healing and scarless repair in vivo. This study presents a novel approach to the development of cutaneous wound dressing materials.

An Injectable, Adhesive, and Self-Healing Hydrogel with Inherently Antibacterial Property for Wound Dressing

Antibacterial hydrogel has emerged as an excellent candidate for wound dressing with the ability to eliminate infection and promote wound healing. Herein, a dynamic hydrogel is developed by Schiff base reaction of mixed charged polypeptides and oxidized dextran (ODex). Specifically, biodegradable polypeptides of 1-(propylthio)acetic acid-3-butylimidazole-modified poly(L-lysine) (PLL-PBIM) and adipate dihydrazide-modified poly(L-glutamic acid) (PLG-ADH) are achieved with tunable substitution and charge. By mixing with ODex, charged polypeptides of PLL-PBIM and PLG-ADH led to an injectable and self-healing hydrogel in seconds. The injectable and self-healing performances of the hydrogels are ascribed to the reversible imine and hydrazone bonds formed between polypeptides and ODex. The positively charged hydrogels exhibited over 95% antibacterial activity against E. coli and S. aureus. An optimized balancing of PLG-ADH and PLL-PBIM significantly reduced the hemolysis rate and cytotoxicity of hydrogels. Therefore, the dynamic hydrogel with excellent biocompatibility and inherently antibacterial ability can have potential application for wound dressing.

Hyaluronic Acid-Based Reactive Oxygen Species-Responsive Multifunctional Injectable Hydrogel Platform Accelerating Diabetic Wound Healing

Diabetic wounds are more likely to develop into complex and severe chronic wounds. The objective of this study is to develop and assess a reactive oxygen species (ROS)-responsive multifunctional injectable hydrogel for the purpose of diabetic wound healing. A multifunctional hydrogel (HA@Cur@Ag) is successfully synthesized with dual antioxidant, antibacterial, and anti-inflammatory properties by crosslinking thiol hyaluronic acid (SH-HA) and disulfide-bonded hyperbranched polyethylene glycol (HB-PBHE) through Michael addition; while, incorporating curcumin liposomes and silver nanoparticles (AgNPs). The HA@Cur@Ag hydrogel exhibits favorable biocompatibility, degradability, and injectivity. The outcomes of in vitro and in vivo experiments demonstrate that the hydrogel can effectively be loaded with and release curcumin liposomes, as well as silver ions, thereby facilitating diabetic wound healing through multiple mechanisms, including ROS scavenging, bactericidal activity, anti-inflammatory effects, and the promotion of angiogenesis. Transcriptome sequencing reveals that the HA@Cur@Ag hydrogel effectively suppresses the activation of the tumour necrosis factor (TNF)/nuclear factor κB (NF-κB) pathway to ameliorate oxidative stress and inflammation in diabetic wounds. These findings suggest that this ROS-responsive multifunctional injectable hydrogel, which possesses the ability to precisely coordinate and integrate intricate biological and molecular processes involved in wound healing, exhibits notable potential for expediting diabetic wound healing.

A light-sensitive protein-based wearable pH biometer

Bacteriorhodopsin is a biological material with excellent photosensitivity properties. It can directly convert optical signals into electrical signals and is widely used in various biosensors. Here, we present a bR-based wearable pH biometer that can be used to monitor wound infection. The mechanism of the pH-sensitive effect of the bR electrode is explained, which generates a transient photovoltage under light irradiation and a negative photovoltage when the lamp is turned off. Since the photoelectric signal of bR is affected by different pH values, the photovoltage is changed by adjusting the pH value. The ratio (Vn/Vp) of negative photovoltage (Vn) to positive photovoltage (Vp) has a good linear relationship (R2 = 0.9911) in the pH range of 4.0-10.0. In vitro experiments using rats as a model confirmed that this wearable pH biometer can monitor pH changes that occur in wound infection.

Low-Dose Trypsin Accelerates Wound Healing via Protease-Activated Receptor 2

The management of wounds remains a significant healthcare challenge, highlighting the need for effective wound healing strategies. To address this, it is crucial to explore the molecular mechanisms underlying tissue repair as well as explore potential therapeutic approaches. Trypsin, as a serine protease, has been clinically utilized for wound healing for decades; however, it still lacks systemic investigation on its role and related mechanism. This study aimed to investigate the effects of low-dose trypsin on wound healing both in vitro and in vivo. While trypsin is an endogenous stimulus for protease-activated receptor 2 (PAR2), we discovered that both low-dose trypsin and synthesized PAR2 agonists significantly enhanced the migration, adhesion, and proliferation of fibroblasts and macrophages, similar to the natural repair mechanism mediated by mast cell tryptase. Moreover, such cell functions induced by trypsin were largely inhibited by PAR2 blockade, indicating the participation of trypsin via PAR2 activation. Additionally, low-dose trypsin notably expedited healing and regeneration while enhancing collagen deposition in skin wounds in vivo. Importantly, upon stimulation of trypsin or PAR2 agonists, there were significant upregulations of genes including claudin-7 (Cldn7), occludin (Ocln), and interleukin-17A (IL-17A) associated with proliferation and migration, extracellular matrix (ECM), tight junction, and focal adhesion, which contributed to wound healing. In summary, our study suggested that a low-dose trypsin could be a promising strategy for wound healing, and its function was highly dependent on PAR2 activation.

Facile one-pot synthesis of flower-like ellagic acid microparticles incorporating anti-microbial peptides for enhanced wound healing

Anti-microbial peptides (AMPs) have gained significant attention as potential antimicrobial agents due to their cytocompatibility and reduced drug resistance. However, AMPs often suffer from low stability due to their vulnerable molecular structure. This study presents a one-pot synthesis method for ellagic acid (EA)-based, flower-like AMPs@EAMP particles, combining the antibacterial properties of EA with AMPs. The resulting particles exhibit an enlarged surface area for the adsorption or embedding of AMPs, enhancing their antibacterial efficacy. Furthermore, in vitro evaluations demonstrate excellent biocompatibility and broad-spectrum activity against bacterial strains including both Gram-positive S. epidermidis and Gram-negative E. coli. In vivo studies indicate AMPs@EAMPs' potential to reconstruct the immune barrier, inhibit pathogens, and reduce inflammation, promoting orderly tissue repair. This innovative synthesis strategy provides a straightforward and effective approach for large-scale production of flower-like AMPs@EAMP particles with remarkable antibacterial properties, addressing the challenges associated with MDR infections.

High-efficiency antibacterial calcium alginate/lysozyme/AgNPs composite sponge for wound healing

Infection poses a significant barrier to effective wound repair, leading to increased inflammatory responses that ultimately result in incomplete and prolonged wound healing. To address this challenge, numerous antibacterial ingredients have been incorporated into dressings to inhibit wound infection. Our previous work demonstrated that lysozyme/silver nanoparticles (LYZ/AgNPs) complexes, prepared using an eco-friendly one-step aqueous method, exhibited excellent antibacterial efficacy with favorable biosafety. To further explore its potential application in advancing wound healing, calcium alginate (CA) with good porosity, water absorption, and water retention capacities was formulated with LYZ/AgNPs to prepare composite sponge (CA/LYZ/AgNPs). As expected, in vivo experiments involving full-thickness skin wound and scald wound healing experiments demonstrated that CA-LYZ-AgNPs composite sponges with excellent biocompatibility exhibited remarkable antibacterial activity against gram-positive bacteria, gram-negative bacteria and fungi, and outperformed the wound healing process efficacy of other commercially available AgNPs-loaded wound dressings. In summary, this work introduces a CA/LYZ/AgNPs sponge featuring exceptional antibacterial efficacy and biocompatibility, thus holding promising potential in wound care applications.

Enhanced healing of wounds that responded poorly to silver dressing by copper wound dressings: Prospective single arm treatment study

Background and Aims

Dressings containing silver ions are an accepted and common option for wound treatment. However, some wounds fail to heal at the desired rate despite optimal management. The aim of the study was to examine the effect of copper dressings in noninfected wounds.

Methods

The study included 20 patients aged 18-85 years with 2-30 cm2 noninfected wounds treated for 17-41 days with silver wound dressings that failed to reduce by >50% the wound size, who were then treated with copper dressings. Ten patients were diabetics, 10 suffered from hypertension, and six suffered from peripheral vascular disease (PVD). Two patients suffered from two wounds. Most were amputation wounds below the knee.

Results

Five patients dropped out from the study due to complications not related to the wound. The mean period of silver and copper dressings treatment was 25.6 and 29.6 days, respectively (p = 0.25; t test). None of the wounds became infected. Comparing a period of 25 days, during the copper dressings treatment, the mean wound area reduction was ~2.4 times higher than during the silver dressing treatment, 87.35 ± 22.4% versus 37.02 ± 25.11% (mean ± SD; p < 0.001; paired t test), respectively. The average decline during the silver and copper treatments were 1.2% and 2.14% per day (p = 0.002; multiple regression analysis), respectively.

Conclusions

The enhanced wound healing process observed with the copper dressings may be explained by the integral role of copper throughout all physiological skin repair processes. Silver in contrast has no physiological role in wound healing. The results of our study confirm case reports showing enhanced wound healing of hard-to-heal wounds with copper dressings, both of infected and noninfected wounds. Taken together, the results of the current study support the hypothesis that the application of copper dressings in situ for noninfected wounds results in the stimulation of the wound healing processes, as opposed to silver dressings.

Fibrous matrices facilitate pleurocidin killing of wound associated bacterial pathogens

Conventional wound infection treatments neither actively promote wound healing nor address the growing problem of antibacterial resistance. Antimicrobial peptides (AMPs) are natural defense molecules, released from host cells, which may be rapidly bactericidal, modulate host-immune responses, and/or act as endogenous mediators for wound healing. However, their routine clinical use has hitherto been hindered due to their instability in the wound environment. Here we describe an electrospun carrier system for topical application of pleurocidin, demonstrating sufficient AMP release from matrices to kill wound-associated pathogens including Acinetobacter baumannii and Pseudomonas aeruginosa. Pleurocidin can be incorporated into polyvinyl alcohol (PVA) fiber matrices, using coaxial electrospinning, without major drug loss with a peptide content of 0.7% w/w predicted sufficient to kill most wound associated species. Pleurocidin retains its activity on release from the electrospun fiber matrix and completely inhibits growth of two strains of A. baumannii (AYE; ATCC 17978) and other ESKAPE pathogens. Inhibition of P. aeruginosa strains (PAO1; NCTC 13437) is, however, matrix weight per volume dependent, with only larger/thicker matrices maintaining complete inhibition. The resulting estimation of pleurocidin release from the matrix reveals high efficiency, facilitating a greater AMP potency. Wound matrices are often applied in parallel or sequentially with the use of standard wound care with biocides, therefore the presence and effect of biocides on pleurocidin potency was tested. It was revealed that combinations displayed additive or modestly synergistic effects depending on the biocide and pathogens which should be considered during the therapy. Taken together, we show that electrospun, pleurocidin-loaded wound matrices have potential to be investigated for wound infection treatment.

Alkaline phosphatase LapA regulates quorum sensing-mediated virulence and biofilm formation in Pseudomonas aeruginosa PAO1 under phosphate depletion stress

IMPORTANCE

Our previous study demonstrated that the expression of lapA was induced under phosphate depletion conditions, but its roles in virulence and biofilm formation by Pseudomonas aeruginosa remain largely unknown. This study presents a systematic investigation of the roles of lapA in virulence induction and biofilm formation by constructing a lapA-deficient strain with P. aeruginosa PAO1. The results showed that deletion of the lapA gene evidently reduced elastase activity, swimming motility, C4-HSL, and 3-oxo-C12-HSL production, and increased rhamnolipid production under phosphate depletion stress. Moreover, lapA gene deletion inhibited PAO1 biofilm formation in porcine skin explants by reducing the expression levels of las and rhl quorum sensing systems and extracellular polymeric substance synthesis. Finally, lapA gene deletion also reduced the virulence of PAO1 in Caenorhabditis elegans in fast-kill and slow-kill infection assays. This study provides insights into the roles of lapA in modulating P. aeruginosa virulence and biofilm formation under phosphate depletion stress.

Data-driven digital health technologies in the remote clinical care of diabetic foot ulcers: a scoping review

Background

The availability and effectiveness of Digital Health Technologies (DHTs) to support clinicians, empower patients, and generate economic savings for national healthcare systems are growing rapidly. Of particular promise is the capacity of DHTs to autonomously facilitate remote monitoring and treatment. Diabetic Foot Ulcers (DFUs) are characterised by high rates of infection, amputation, mortality, and healthcare costs. With clinical outcomes contingent on activities that can be readily monitored, DFUs present a promising focus for the application of remote DHTs.

Objective

This scoping review has been conducted as a first step toward ascertaining fthe data-related challenges and opportunities for the development of more comprehensive, integrated, and individualised sense/act DHTs. We review the latest developments in the application of DHTs to the remote care of DFUs. We cover the types of DHTs in development and their features, technological readiness, and scope of clinical testing.

Eligibility criteria

Only peer-reviewed original experimental and observational studies, case series and qualitative studies were included in literature searches. All reviews and manuscripts presenting pre-trial prototype technologies were excluded.

Methods

An initial search of three databases (Web of Science, MEDLINE, and Scopus) generated 1,925 English-language papers for screening. 388 papers were assessed as eligible for full-text screening by the review team. 81 manuscripts were found to meet the eligibility criteria.

Results

Only 19% of studies incorporated multiple DHTs. We categorised 56% of studies as 'Treatment-Manual', i.e. studies involving technologies aimed at treatment requiring manual data generation, and 26% as 'Prevention-Autonomous', i.e. studies of technologies generating data autonomously through wearable sensors aimed at ulcer prevention through patient behavioural change. Only 10% of studies involved more ambitious 'Treatment-Autonomous' interventions. We found that studies generally reported high levels of patient adherence and satisfaction.

Conclusions

Our findings point to a major potential role for DHTs in remote personalised medical management of DFUs. However, larger studies are required to assess their impact. Here, we see opportunities for developing much larger, more comprehensive, and integrated monitoring and decision support systems with the potential to address the disease in a more complete context by capturing and integrating data from multiple sources from subjective and objective measurements.

Inflammatory Profile Associated with Secondary Infection from Bothrops atrox Snakebites in the Brazilian Amazon

Bothrops snakebite envenomation (SBE) is consider an important health problem in Brazil, where Bothrops atrox is mainly responsible in the Brazilian Amazon. Local effects represent a relevant clinical issue, in which inflammatory signs and symptoms in the bite site represent a potential risk for short and long-term disabilities. Among local complications, secondary infections (SIs) are a common clinical finding during Bothrops atrox SBE and are described by the appearance of signs such as abscess, cellulitis or necrotizing fasciitis in the affected site. However, the influence of SI in the local events is still poorly understood. Therefore, the present study describes for the first time the impact of SBE wound infection on local manifestations and inflammatory response from patients of Bothrops atrox SBE in the Brazilian Amazon. This was an observational study carried out at the Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus (Brazil), involving victims of Bothrops SBE. Clinical and laboratorial data were collected along with blood samples for the quantification of circulating cytokines and chemokines before antivenom administrations (T0) and 24 h (T1), 48 h (T2), 72 h (T3) and 7 days after (T4). From the 94 patients included in this study, 42 presented SI (44.7%) and 52 were without SI (NSI, 55.3%). Patients classified as moderate envenoming presented an increased risk of developing SI (OR = 2.69; CI 95% = 1.08-6.66, p = 0.033), while patients with bites in hands showed a lower risk (OR = 0.20; CI 95% = 0.04-0.96, p = 0.045). During follow-up, SI patients presented a worsening of local temperature along with a sustained profile of edema and pain, while NSI patients showed a tendency to restore and were highlighted in patients where SI was diagnosed at T2. As for laboratorial parameters, leukocytes, erythrocyte sedimentation ratio, fibrinogen and C-reactive protein were found increased in patients with SI and more frequently in patients diagnosed with SI at T3. Higher levels of circulating IL-2, IL-10, IL-6, TNF, INF-γ and CXCL-10 were observed in SI patients along with marked correlations between these mediators and IL-4 and IL-17, showing a plurality in the profile with a mix of Th1/Th2/Th17 response. The present study reports for the first time the synergistic effects of local infection and envenoming on the inflammatory response represented by local manifestations, which reflected on laboratorial parameters and inflammatory mediators and thus help improve the clinical management of SI associated to Bothrops SBE.

Size-dependent gold nanoparticles induce macrophage M2 polarization and promote intracellular clearance of Staphylococcus aureus to alleviate tissue infection

Tissue infection typically results from blood transmission or the direct inoculation of bacteria following trauma. The pathogen-induced destruction of tissue prevents antibiotics from penetrating the infected site, and severe inflammation further impairs the efficacy of conventional treatment. The current study describes the size-dependent induction of macrophage polarization using gold nanoparticles. Gold nanoparticles with a diameter of 50 ​nm (Au50) can induce M2 polarization in macrophages by inhibiting the NF-κB signaling pathway and stimulate an inflammatory response in the environment by inhibiting the MAPK signaling pathway LPS. Furthermore, the induced polarization and anti-inflammatory effects of the Au50 nanoparticles promoted the osteogenic differentiation of BMSCs in vitro. In addition, the overexpression of TREM2 in macrophage induced by Au50 nanoparticles was found to promote macrophage phagocytosis of Staphylococcus aureus, enhance the fusion of autophagosomes and lysosomes, accelerate the intracellular degradation of S. aureus, in addition to achieving an effective local treatment of osteomyelitis and infectious skin defects in conjunction with inflammatory regulation and accelerating bone regeneration. The findings, therefore, demonstrate that Au50 nanoparticles can be utilized as a promising nanomaterial for in vivo treatment of infections.

Chemiluminescent carbon nanodots for dynamic and guided antibacteria

Advanced antibacterial technologies are needed to counter the rapid emergence of drug-resistant bacteria. Image-guided therapy is one of the most promising strategies for efficiently and accurately curing bacterial infections. Herein, a chemiluminescence (CL)-dynamic/guided antibacteria (CDGA) with multiple reactive oxygen species (ROS) generation capacity and chemiexcited near-infrared emission has been designed for the precise theranostics of bacterial infection by employing near-infrared emissive carbon nanodots (CDs) and peroxalate as CL fuels. Mechanistically, hydrogen peroxide generated in the bacterial microenvironment can trigger the chemically initiated electron exchange between CDs and energy-riched intermediate originated from the oxidized peroxalate, enabling bacterial induced inflammation imaging. Meanwhile, type I/II photochemical ROS production and type III ultrafast charge transfer from CDs under the self-illumination can inhibit the bacteria proliferation efficiently. The potential clinical utility of CDGA is further demonstrated in bacteria infected mice trauma model. The self-illuminating CDGA exhibits an excellent in vivo imaging quality in early detecting wound infections and internal inflammation caused by bacteria, and further are proven as efficient broad-spectrum antibacterial nanomedicines without drug-resistance, whose sterilizing rate is up to 99.99%.

The biological and physiological impact of the performance of wound dressings

Chronic wounds affect millions globally and are a huge financial burden. Whilst there are many wound dressings commercially available to manage these wounds, the complexity of the repair process makes it difficult to select the right dressing for the right wound at the right time. Thus, in this narrative review, we have examined reasons why wounds fail to heal, summarised the pathophysiology of the chronic wound environment and provided an evidence-based, clinically-relevant compilation of the published literature relevant to dressing design and evaluation. This has highlighted the need for a deeper understanding of wound exudates, how exudates change throughout the healing process, and how they are impacted by different dressing materials. Studies assessing biochemical and biophysical changes in exudates throughout the healing process are extremely valuable in this regard, enhancing both our understanding of the wound healing process and the ability to assess dressing performance. In addition, this knowledge allows us to replicate various wound conditions in the laboratory, and develop clinically-relevant models for testing current and new dressings, therefore providing a more comprehensive understanding of how and when they should be used. This approach makes the use of dressings more effective, thereby improving outcomes, and reducing the economic burden of chronic wounds.

Applications of MXene and its modified materials in skin wound repair

The rapid healing and repair of skin wounds has been receiving much clinical attention. Covering the wound with wound dressing to promote wound healing is currently the main treatment for skin wound repair. However, the performance of wound dressing prepared by a single material is limited and cannot meet the requirements of complex conditions for wound healing. MXene is a new two-dimensional material with electrical conductivity, antibacterial and photothermal properties and other physical and biological properties, which has a wide range of applications in the field of biomedicine. Based on the pathophysiological process of wound healing and the properties of ideal wound dressing, this review will introduce the preparation and modification methods of MXene, systematically summarize and review the application status and mechanism of MXene in skin wound healing, and provide guidance for subsequent researchers to further apply MXene in the design of skin wound dressing.

New insights into balancing wound healing and scarless skin repair

Scars caused by skin injuries after burns, wounds, abrasions and operations have serious physical and psychological effects on patients. In recent years, the research of scar free wound repair has been greatly expanded. However, understanding the complex mechanisms of wound healing, in which various cells, cytokines and mechanical force interact, is critical to developing a treatment that can achieve scarless wound healing. Therefore, this paper reviews the types of wounds, the mechanism of scar formation in the healing process, and the current research progress on the dual consideration of wound healing and scar prevention, and some strategies for the treatment of scar free wound repair.

Wide Spectrum Potent Antimicrobial Efficacy of Wound Dressings Impregnated with Cuprous Oxide Microparticles

Copper has intrinsic antimicrobial properties. Wound dressings impregnated with cuprous oxide microparticles (hereafter termed COD) have been cleared for the management of acute and chronic wounds by the FDA and other regulatory bodies. The COD reduced the viable microbial titers of a wide spectrum of microbes by more than 10,000-fold (4-logs) within 3 h of exposure at 37 °C (p < 0.001). Similar microbial titer reductions were achieved by 3-year naturally aged COD dressings, showing the stability of the biocidal efficacy over time. The potent biocidal efficacy of the COD was maintained even after 7 daily consecutive inoculations of the dressings with ~106 CFU. COD with an adhesive contour blocked the passage of bacteria from the exterior environment to the wound bed side of the dressing even after 7 daily consecutive inoculations of different bacteria on the outer surface of the dressings. Taken together, the study demonstrates the wide spectrum potent in vitro biocidal efficacy of the cuprous oxide impregnated dressings against a wide panel of microorganisms.