Dermal extracellular matrix molecules in skin development, homeostasis, wound regeneration and diseases.

The extracellular matrix (ECM) is a dynamic structure that surrounds and anchors cellular components in tissues. In addition to functioning as a structural scaffold for cellular components, ECMs also regulate diverse biological functions, including cell adhesion, proliferation, differentiation, migration, cell-cell interactions, and intracellular signaling events. Dermal fibroblasts (dFBs), the major cellular source of skin ECM, develop from a common embryonic precursor to the highly heterogeneous subpopulations during development and adulthood. Upon injury, dFBs migrate into wound granulation tissue and transdifferentiate into myofibroblasts, which play a critical role in wound contraction and dermal ECM regeneration and deposition. In this review, we describe the plasticity of dFBs during development and wound healing and how various dFB-derived ECM molecules, including collagen, proteoglycans, glycosaminoglycans, fibrillins and matricellular proteins are expressed and regulated, and in turn how these ECM molecules play a role in regulating the function of dFBs and immune cells. Finally, we describe how dysregulation of ECM matrix is associated the pathogenesis of wound healing related skin diseases, including chronic wounds and keloid.

A Multifunctional Herb-Derived Glycopeptide Hydrogel for Chronic Wound Healing.

Chronic wounds constitute an increasingly prevalent global healthcare issue, characterized by recurring bacterial infections, pronounced oxidative stress, compromised functionality of immune cells, unrelenting inflammatory reactions, and deficits in angiogenesis. In response to these multifaceted challenges, the study introduced a stimulus-responsive glycopeptide hydrogel constructed by oxidized Bletilla striata polysaccharide (OBSP), gallic acid-grafted ε-Polylysine (PLY-GA), and paeoniflorin-loaded micelles (MIC@Pae), called OBPG&MP. The hydrogel emulates the structure of glycoprotein fibers of the extracellular matrix (ECM), exhibiting exceptional injectability, self-healing, and biocompatibility. It adapts responsively to the inflammatory microenvironment of chronic wounds, sequentially releasing therapeutic agents to eradicate bacterial infection, neutralize reactive oxygen species (ROS), modulate macrophage polarization, suppress inflammation, and encourage vascular regeneration and ECM remodeling, playing a critical role across the inflammatory, proliferative, and remodeling phases of wound healing. Both in vitro and in vivo studies confirmed the efficacy of OBPG&MP hydrogel in regulating the wound microenvironment and enhancing the regeneration and remodeling of chronic wound skin tissue. This research supports the vast potential for herb-derived multifunctional hydrogels in tissue engineering and regenerative medicine.

Platelet-Derived Growth Factor Nanocapsules with Tunable Controlled Release for Chronic Wound Healing.

Chronic wounds have emerged as an increasingly critical clinical challenge over the past few decades, due to their increasing incidence and socioeconomic burdens. Platelet-derived growth factor (PDGF) plays a pivotal role in regulating processes such as fibroblast migration, proliferation, and vascular formation during the wound healing process. The delivery of PDGF offers great potential for expediting the healing of chronic wounds. However, the clinical effectiveness of PDGF in chronic wound healing is significantly hampered by its inability to maintain a stable concentration at the wound site over an extended period. In this study, a controlled PDGF delivery system based on nanocapsules is proposed. In this system, PDGF is encapsulated within a degradable polymer shell. The release rate of PDGF from these nanocapsules can be precisely adjusted by controlling the ratios of two crosslinkers with different degradation rates within the shells. As demonstrated in a diabetic wound model, improved therapeutic outcomes with PDGF nanocapsules (nPDGF) treatment are observed. This research introduces a novel PDGF delivery platform that holds promise for enhancing the effectiveness of chronic wound healing.

Development and functional testing of a novel in vitro delayed scratch closure assay.

As the development of chronic wound therapeutics continues to expand, the demand for advanced assay systems mimicking the inflammatory wound microenvironment in vivo increases. Currently, this is performed in animal models or in in vitro cell-based models such as cell culture scratch assays that more closely resemble acute wounds. Here, we describe for the first time a delayed scratch closure model that mimics some features of a chronic wound in vitro. Chronic wounds such as those suffered by later stage diabetic patients are characterised by degrees of slowness to heal caused by a combination of continued localised physical trauma and pro-inflammatory signalling at the wound. To recreate this in a cell-based assay, a defined physical scratch was created and stimulated by combinations of pro-inflammatory factors, namely interferon, the phorbol ester PMA, and lipopolysaccharide, to delay scratch closure. The concentrations of these factors were characterised for commonly used human keratinocyte (HaCaT) and dermal fibroblast (HDF) cell lines. These models were then tested for scratch closure responsiveness to a proprietary healing secretome derived from human Wharton's jelly mesenchymal stem cells (MSCs) previously validated and shown to be highly effective on closure of acute wound models both in vitro and in vivo. The chronically open scratches from HaCaT cells showed closure after exposure to the MSC secretome product. We propose this delayed scratch closure model for academic and industrial researchers studying chronic wounds looking for responsiveness to drugs or biological treatments prior to testing on explanted patient material or in vivo.

Vagus nerve stimulation: Potential for treating chronic wounds.

Vagus nerve stimulation (VNS) has been approved as a treatment for various conditions, including drug-resistant epilepsy, migraines, chronic cluster headaches and treatment-resistant depression. It is known to have anti-inflammatory, anti-nociceptive and anti-adrenergic effects, and its therapeutic potential for diverse pathologies is being investigated. VNS can be achieved through invasive (iVNS) or non-invasive (niVNS) means, targeting different branches of the vagus nerve. iVNS devices require surgical implantation and have associated risks, while niVNS devices are generally better tolerated and have a better safety profile. Studies have shown that both iVNS and niVNS can reduce inflammation and pain perception in patients with acute and chronic conditions. VNS devices, such as the VNS Therapy System and MicroTransponder Vivistim, have received Food and Drug Administration approval for specific indications. Other niVNS devices, like NEMOS and gammaCore, have shown effectiveness in managing epilepsy, pain and migraines. VNS has also demonstrated potential in autoimmune disorders, such as rheumatoid arthritis and Crohn's disease, as well as neurological disorders like epilepsy and migraines. In addition, VNS has been explored in cardiovascular disorders, including post-operative atrial fibrillation and myocardial ischemia-reperfusion injury, and has shown positive outcomes. The mechanisms behind VNS's effects include the cholinergic anti-inflammatory pathway, modulation of cytokines and activation of specialised pro-resolving mediators. The modulation of inflammation by VNS presents a promising avenue for investigating its potential to improve the healing of chronic wounds. However, more research is needed to understand the specific mechanisms and optimise the use of VNS in wound healing. Ongoing clinical trials may support the use of this modality as an adjunct to improve healing.

Therapeutic potential of silkworm sericin in wound healing applications.

Chronic wounds are characterised by an imbalance between pro and anti-inflammatory signals, which result in permanent inflammation and delayed re-epithelialization, consequently hindering wound healing. They are associated with bacterial infections, tissue hypoxia, local ischemia, reduced vascularization, and MMP-9 upregulation. The global prevalence of chronic wounds has been estimated at 40 million in the adult population, with an alarming annual growth rate of 6.6%, making it an increasingly significant clinical problem. Sericin is a natural hydrophilic protein obtained from the silkworm cocoon. Due to its biocompatibility, biodegradability, non-immunogenicity, and oxidation resistance, coupled with its excellent affinity for target biomolecules, it holds great potential in wound healing applications. The silk industry discards 50,000 tonnes of sericin annually, making it a readily available material. Sericin increases cell union sites and promotes cell proliferation in fibroblasts and keratinocytes, thanks to its cytoprotective and mitogenic effects. Additionally, it stimulates macrophages to release more therapeutic cytokines, thus improving vascularization. This review focuses on the biological properties of sericin that contribute towards enhanced wound healing process and its mechanism of interaction with important biological targets involved in wound healing. Emphasis is placed on diverse wound dressing products that are sericin based and the utilisation of nanotechnology to design sericin nanoparticles that aid in chronic wound management.

Advanced meta-analysis on therapeutic strategies of mesenchymal derived exosome for diabetic chronic wound healing and tissue remodeling.

BACKGROUND: Exosome (EXOs) are rapidly being identified as key mediators of cell-to-cell communication. They convey biologically active molecules to target cells, serve important roles in a range of physiological and pathological processes, and have enormous potential as novel therapeutic strategies. METHODS: Preclinical research published between 2019 and 2023 provided the study's data searched on different medline search engine, and clinicaltrials.gov was searched for clinical data. These papers were chosen because they are relevant to the research of mesenchymal stem cell-derived exosomes (MSC-EXOs). Thematic synthesis and meta-analysis were used to perform the meta-analysis of diabetic wound healing. RESULTS: For data extraction, a total of 18 preclinical and 4 clinical trials were selected. Preclinical investigations involving EXOs across various animal wound healing models showed promising potential for treatment. Specifically, following EXO treatment, there was a notable correlation with wound closure rates, with a pooled proportion of 46 % (95 % CI: 0.34; 0.59) and τ2 of 0.0593 after 3 ± 2 days, 54 % (95 % CI: 0.43; 0.65) and τ2 of 0.0465 after 7 ± 2 days, and 69 % (95 % CI: 0.62; 0.76) and τ2 of 0.0221 after 14 ± 2 days, with an egger's test p-value of <0.01. Further investigation into heterogeneity was conducted through subgroup analysis based on the source of EXO and the animal model utilized in the study. CONCLUSIONS: EXOs are proving to be viable platforms for the treatment of a wide range of disorders in clinical trials. MSC-EXOs exhibited significant diabetic wound healing capabilities across diverse outcomes including wound closure, increase angiogenesis, immunomodulatory ability and skin regeneration with its typical structure and functions.

Liver insulin-like growth factor-1 mediates effects of low-intensity vibration on wound healing in diabetic mice.

Chronic wounds in diabetic patients are associated with significant morbidity and mortality; however, few therapies are available to improve healing of diabetic wounds. Our group previously reported that low-intensity vibration (LIV) could improve angiogenesis and wound healing in diabetic mice. The purpose of this study was to begin to elucidate the mechanisms underlying LIV-enhanced healing. We first demonstrate that LIV-enhanced wound healing in db/db mice is associated with increased IGF1 protein levels in liver, blood, and wounds. The increase in insulin-like growth factor (IGF) 1 protein in wounds is associated with increased Igf1 mRNA expression both in liver and wounds, but the increase in protein levels preceded the increase in mRNA expression in wounds. Since our previous study demonstrated that liver was a primary source of IGF1 in skin wounds, we used inducible ablation of IGF1 in the liver of high-fat diet (HFD)-fed mice to determine whether liver IGF1 mediated the effects of LIV on wound healing. We demonstrate that knockdown of IGF1 in liver blunts LIV-induced improvements in wound healing in HFD-fed mice, particularly increased angiogenesis and granulation tissue formation, and inhibits the resolution of inflammation. This and our previous studies indicate that LIV may promote skin wound healing at least in part via crosstalk between the liver and wound. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Novel Sprayable Antioxidative Dressing Based on Fullerene and Curdlan for Accelerating Chronic Wound Healing.

The effective treatment of chronic wounds represents a critical global medical challenge demanding urgent attention. Persistent inflammation, driven by an excess of reactive oxygen radicals, sets in motion a detrimental cycle leading to chronic wounds and impeding the natural healing process. This study develops a sprayable wound dressing by covalently grafting amino fullerene to carboxymethylated curdlan (CMC-C). This novel dressing exhibits excellent biocompatibility, antioxidant, and reactive oxygen species scavenging properties. Furthermore, it demonstrates a targeted affinity for HEK-a cells, efficiently reducing the inflammatory response while promoting cell proliferation and migration in vitro. Moreover, the animal experiment investigations reveal that CMC-C significantly accelerates chronic wounds healing by regulating the inflammatory process, promoting collagen deposition, and improving vascularization. These results demonstrate the potential of the sprayable dressing (CMC-C) in curing the healing of chronic wounds through the modulation of the inflammatory microenvironment. Overall, the sprayable hydrogel dressing based on water-soluble derivative of fullerene and curdlan emerges as a potential approach for clinical applications in the treatment of chronic wounds.

Efficacy of acellular fish skin graft in the management of chronic ulcer: a systematic review and meta-analysis.

BACKGROUND: The wounds failing to heal through a timely and orderly standard of care (SOC) treatment are considered as chronic wounds, which add significant burden to healthcare systems around the world. SOC treatment has been commonly applied for management of chronic wounds, but SOC alone may not be adequate to heal all ulcers effectively. Fish skin graft (FSG) is a xenogenic skin substitute which could be used for accelerating skin healing. The current study was performed with the view of evaluating the effectiveness of FSG as an adjuvant treatment of SOC for chronic ulcer treatment. METHODS: Two authors independently searched the following electronic databases: PubMed, Embase, and CENTRAL, using keywords including "diabetic foot ulcer," "fish skin graft," and "wound healing." Clinical studies that evaluated the clinical outcomes of FSG in treatment of chronic ulcers were included in this meta-analysis. Random- or fixed-effect modeled meta-analyses were performed according to the heterogeneity test result (i.e., I2), to analyze the clinical outcome of FSG. RESULTS: A total of 8 studies were included in qualitative synthesis and meta-analysis, with 145 patients treated by SOC and 245 patients treated by SOC plus FSG. There was no significant difference between two groups for time to healing (MD = 1.99, 95% CI: -3.70~7.67, p = 0.493). The complete healing rate was significantly higher in FSG group compared with SOC alone (OR = 3.44, 95% CI: 2.03~5.82, p < 0.001***). Mean percentage area reduction (PAR) was reported in six studies, with a range of 71.6~97.3%. However, many of these studies did not report the value of standard deviation (SD), so we could not pool the data. No significantly different ulcer recurrence rate (RR = 0.60, 95% CI: 0.07~5.27, p = 0.645) and severe adverse events (SAEs) risk (RR = 1.67, 95% CI: 0.42~6.61, p = 0.467) were found between two groups. CONCLUSIONS: The application of FSG treatment for patients with chronic ulcers that do not respond well to SOC management could significantly increase the complete healing rate compared with SOC alone, without increased recurrence rate and SAEs risk.

Complication of head and neck cancer: Carotid blowout syndrome.

Carotid blowout syndrome (CBS) is an uncommon but potentially life-threatening condition characterized by the spontaneous or traumatic rupture of the carotid artery in the neck. Oftentimes, CBS is due a loss of structural arterial integrity from local radiotherapy or surgical procedures. A vast majority of patients who develop CBS also have a previous diagnosis of head and neck cancer. Due to the specific patient population who develop CBS and its life-threatening nature, CBS should be a part of emergency physicians differential for those who present with a chronic neck wound or neurological symptoms in those with a previous head and neck cancer diagnosis. In this case report, a patient with a history of squamous cell carcinoma of the oropharynx who was treated with chemoradiation therapy, presented to the emergency department with spontaneous bleeding from an existing chronic wound on the left lateral neck. Conservative measures were taken including wound dressing, and the patient was discharged to see dermatology for biopsy of a suspected cancerous lesion. Once the chronic lesion was biopsied, the patient had to be immediately rushed to the operating room due to a brisk pulsatile bleeding from puncturing the carotid artery. Proper wound packing and an ultrasound of the neck for a proper diagnosis may have prevented the need for surgical intervention in this case. Although CBS is not common, complications can lead to death as seen in this case. Timely recognition and proper interventions are critical for preventing potentially fatal outcomes in those with CBS.

Intermittent lysis on a single paper-based device to extract exosomal nucleic acid biomarkers from biological samples for downstream analysis.

As the role of exosomes in physiological and pathological processes has been properly perceived, harvesting them and their internal components is critical for subsequent applications. This study is a debut of intermittent lysis, which has been integrated into a simple and easy-to-operate procedure on a single paper-based device to extract exosomal nucleic acid biomarkers for downstream analysis. Exosomes from biological samples were captured by anti-CD63-modified papers before being intermittently lysed by high-temperature, short-time treatment with double-distilled water to release their internal components. Exosomal nucleic acids were finally adsorbed by sol-gel silica for downstream analysis. Empirical trials not only revealed that sporadically dropping 95 °C ddH2O onto the anti-CD63-modified papers every 5 min for 6 times optimized the exosomal nucleic acids extracted by the anti-CD63 paper but also verified that the whole deployed procedure is applicable for point-of-care testing (POCT) in low-resource areas and for both in vitro (culture media) and in vivo (plasma and chronic lesion) samples. Importantly, downstream analysis of exosomal miR-21 extracted by the paper-based procedure integrated with this novel technique discovered that the content of exosomal miR-21 in chronic lesions related to their stages and the levels of exosomal carcinoembryonic antigen originated from colorectal cancer cells correlated to their exosomal miR-21.

Wellbeing, quality of life and satisfaction of patients with hard-to-heal wounds: a descriptive study.

OBJECTIVE: A hard-to-heal wound is defined as a wound that failed to proceed through the normal phases of wound healing in an orderly and timely manner. The purpose of this article is to describe the impact of hard-to-heal wounds on the wellbeing, quality of life (QoL) and satisfaction with QoL of patients in Oman with hard-to-heal wounds. METHOD: A descriptive cross-sectional study of patients with hard-to-heal wounds attending three tertiary care hospitals using a self-reported questionnaire was conducted. RESULTS: A total of 275 patients took part in the study. Patients reported a low wellbeing score (67.06±19.72), moderate QoL score (52.18±25.07) and moderate satisfaction scores (68.91±23.88). Significant mean differences were reported with age, sex, educational level, monthly income and type of wound all at p<0.05. CONCLUSION: The findings of this study demonstrated that hard-to-heal wounds could influence the wellbeing, QoL and overall satisfaction with QoL of patients. DECLARATION OF INTEREST: Funding was received through an internal grant of the Sultan Qaboos University to conduct the research conducting the research (IG/CON/FACN/20/01). The authors have no conflicts of interest to declare.

A double-blind trial comparing an antimicrobial combination to standard care in hard-to-heal wounds.

OBJECTIVE: Excessive numbers of bacteria in hard-to-heal wounds impede wound healing. Numerous topical antiseptics have demonstrated effectiveness in benchtop studies; however, few clinical studies have demonstrated efficacy in the target population: patients with hard-to-heal wounds. This study addressed the clinical efficacy of a novel antibiofilm cleanser and gel in reducing bacterial load and improving wound outcomes. METHOD: Hard-to-heal wounds were photographed, measured and evaluated for bacterial load using fluorescence imaging weekly for four weeks. The target ulcers were randomised to be cleaned and treated with either a synergistic antibiofilm cleanser and antibiofilm gel with standard of care (AMC-AMG + SoC) or normal saline wash and an amorphous gel with standard of care (NSS-HG + SoC). RESULTS: A Chi-squared test of independence determined that the relationship between the treatment and the patient reaching 40% percentage area reduction (PAR) in four weeks was not significant (χ2(1, n=54)=0.73; p=0.39 at a significance level of 0.05); however, there was a strong trend favouring the antibiofilm cleanser and gel. A significant reduction (p<0.05) in bacterial load was observed in the antibiofilm group. CONCLUSION: This randomised controlled double-blind proof-of-concept study suggests that the performance of antibiofilm agents in vivo is comparable to that in vitro studies.

Topical application of hyaluronic acid and amino acids in hard-to-heal wounds: a cost-effectiveness analysis.

OBJECTIVE: The aim of this cost-effectiveness analysis was to estimate the monetary cost required to achieve a gain in health benefit. An analytic model to evaluate the cost-effectiveness of a topical medical device comprising a mixture of hyaluronic acid and amino acids (HA+AA medical device) (Vulnamin, Professional Dietetics SpA, Italy) as compared to standard of care (SoC) for hard-to-heal (chronic) wounds is presented. METHOD: Retrospective data was analysed from a cohort of patients as well as information from published literature. For each paper, the following information was extracted: number of patients enrolled in each treatment arm and the results of prespecified reviewed outcomes. RESULTS: A total of six studies involving 378 patients were included in this pooled analysis. Findings showed that treatment with the HA+AA medical device has the potential to lower consumption of resources. With regards to wound healing, in both superficial and deep wounds, treatment benefits of the HA+AA medical device included: rapid wound size reduction; faster healing; reduction of dressing changes; reduced infection risk; and reduced treatment costs. Results showed the HA+AA medical device to be 32% more cost-effective than comparators in the treatment of hard-to-heal wounds (time horizon selected=six months). CONCLUSION: The findings of this analysis showed that treatment with the HA+AA medical device is a valid alternative to SoC care because it is cheaper, and its utility and effectiveness are greater. In addition, the results of the analysis showed a direct relationship between the time to complete healing and the increase in costs (increasing the period of time to reach complete healing increases the costs associated with the treatment).

Microjet wound therapy versus sharp debridement on wound size reduction: a pilot randomised controlled trial.

OBJECTIVE: There are several methods of treating hard-to-heal (chronic) wounds, each differing in terms of efficiency, selectivity, speed, cost and pain. The objective is to activate a wound to initiate the healing cascade. For this pilot study we assessed the feasibility of a new microjet wound therapy technology compared to standard sharp debridement in wound outcomes. METHOD: A randomised, controlled, open-label pilot study was conducted in one outpatient wound clinic in Western Switzerland from March 2022 to May 2023. RESULTS: A total of 13 consecutive patients were randomly assigned to receive either microjet wound therapy (n=5) or standard mechanical debridement with instruments (n=8). As a feasibility study, there was insufficient power to detect significant differences between the groups. However, in the intervention group, our analysis may indicate a modestly faster reduction in wound area. Microjet wound therapy appears to alleviate patient anxiety and offer cost savings due to the potential for reduced time, as well as the number of required treatments. This meant fewer overall consultations. CONCLUSION: This study highlights a trend that may indicate that microjet therapy holds value in promoting faster healing of hard-to-heal wounds, and it provides a feasibility basis for a sufficiently powered multicentre trial.

Performance of a silicone foam dressing in management of wounds in a community setting: a sub-analysis of the VIPES study.

OBJECTIVE: Managing the gap between the dressing and the wound bed can facilitate the healing of exuding wounds. A silicone foam dressing (Biatain Silicone; Coloplast A/S, Denmark) was developed for application to exuding wounds. A sub-analysis of the real-world, prospective, observational VIPES (Observatoire en Ville des Plaies ExSudatives) study was conducted to investigate the use and performance of the silicone foam dressing in a community nursing setting in France. METHOD: The sub-analysis included patients from the VIPES study who received the silicone foam dressing as a primary dressing for an acute or hard-to-heal (chronic) wound. Epidemiological and wound healing outcomes were reported via a smartphone application. RESULTS: Overall, 64 patients were included in the sub-analysis. At baseline, most wounds (n=33/40; 82.5%) were in treatment failure (i.e., were stagnant, non-healing or had poor exudate management). At the last follow-up visit, a median of 22.5 (range: 3-151) days post baseline, 48.4% of wounds had healed and 25.0% were progressing towards healing. From baseline to the last follow-up visit, significant reductions in exudate level (p<0.0001) and exudate pooling (p<0.0001), and significant improvements in wound edges (p≤0.0001) and periwound skin (p<0.01) were observed. A total of 62.3% of patients had re-epithelialising wounds at the last follow-up visit. The majority of nurses (88.3%) and patients (85.0%) reported that the wound had improved and, at most dressing removals (93.5%), nurses reported that the dressing conformed closely to the wound bed. CONCLUSION: Overall, the data suggest that use of the silicone foam dressing in community practice supported the healing of wounds, illustrating the importance of exudate and gap management.

Pressure ulcers related to prone positioning: a pandemic amidst a pandemic.

OBJECTIVE: To explore the epidemiology and risk factors associated with the development of pressure ulcers (PUs) in patients receiving prone positioning (PP) ventilatory therapy; to compare the inflammatory status of patients who develop PUs with those who do not; and to describe the experience and useful findings that have allowed us to improve the management of these patients to reduce the incidence of PUs. METHOD: An observational, descriptive and longitudinal study was conducted, where sociodemographic and laboratory data were collected from patients who were hospitalised and required PP ventilatory therapy in critical care areas (CCA) during the months of May-October 2020. RESULTS: From the total number of patients who required PP during their CCA stay (n=240), 202 (84.2%) developed a PU. The four most frequent areas where a PU appeared were: the head and neck (n=115); the pinna (n=21); the torso (n=21); and the lower limbs (n=21). Patients who developed PU were more frequently males with higher initial levels of creatinine phosphokinase and ferritin. The incidence for each month of follow-up decreased from 8.3% to 5.8%. CONCLUSION: Regardless of the intervention, a multidisciplinary approach is required to optimise the prevention and treatment of these wounds. While PUs are often the result of other medical conditions or poor health status in general, the vast majority of PUs are avoidable.

Metal-based nanoparticles: an alternative treatment for biofilm infection in hard-to-heal wounds.

Metal-based nanoparticles (MNPs) are promoted as effective compounds in the treatment of bacterial infections and as possible alternatives to antibiotics. These MNPs are known to affect a broad spectrum of microorganisms using a multitude of strategies, including the induction of reactive oxygen species and interaction with the inner structures of the bacterial cells. The aim of this review was to summarise the latest studies about the effect of metal-based nanoparticles on pathogenic bacterial biofilm formed in wounds, using the examples of Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Pseudomonas aeruginosa, as well as provide an overview of possible clinical applications.

Evaluation of risk factors associated with hard-to-heal wound infection in a tertiary care hospital.

OBJECTIVE: The incidence of hard-to-heal wound infection, especially as a result of multidrug-resistant Gram-negative organisms, has increased in recent years. The reason for the increase is multifactorial and the ability of these pathogenic isolates to form biofilms is one of the important risk factors in wound infection. This study aimed to evaluate the risk factors associated with such cases. METHOD: This prospective analytical study, conducted over a period of two months, included pus or tissue samples from hospital inpatients with Gram-negative hard-to-heal wound infection. The samples were processed with conventional microbiological techniques. Patient demographic details and the presence of various risk factors were recorded. Biofilm production was detected by tissue culture plate method in the laboratory. The data were analysed using SPSS version 21 (IBM Ltd., US). RESULTS: The experimental cohort comprised 200 patients. Klebsiella spp. was the most common identified organism, followed by Escherichia coli and Pseudomonas spp. Carbapenem resistance was observed in 106 (53%) strains. Almost 66% of the strains showed biofilm formation. On evaluation of associated risk factors, age (p=0.043), presence of biofilms (p=0.0001), diabetes (p=0.002), hypertension (p=0.02) and medical device use (p=0.008) had significant association, whereas sex, previous surgery and prior antibiotic use had no significant impact on the chronicity of the wound. CONCLUSION: In this study, chronicity of wounds was observed to be associated with multiple risk factors, especially the biofilm-forming ability of the strain. Biofilms are difficult to eradicate and additional measures, such as physical debridement, are important for resolving chronicity. Knowledge about specific risk factors would also allow clinicians a better understanding of the healing process and drive appropriate wound care interventions. DECLARATION OF INTEREST: A grant was received from the Indian Council of Medical Research (ICMR) for this work (grant ID: 2017-02686). The authors have no conflicts of interest to declare.