Topical antimicrobial agents for treating foot ulcers in people with diabetes

The effect of C-terminal deamidation on bacterial susceptibility and resistance to modelin-5

The C-terminal amide carried by antimicrobial peptides (AMPs) can play a variable role in their antibacterial action and here, this role is investigated here for the synthetic peptide modelin-5 (M5-NH2). The peptide showed potent activity against Pseudomonas aeruginosa (MLC = 5.9 µM), with strong binding to the cytoplasmic membrane (CM) (Kd = 21.5 μM) and the adoption of high levels of amphiphilic α-helical structure (80.1%) which promoted strong CM penetration (9.6 mN m-1) and CM lysis (89.0%). In contrast, Staphylococcus aureus was resistant to M5-NH2 (MLC = 139.6 µM), probably due electrostatic repulsion effects mediated by Lys-PG in the organism's CM. These effects promoted weak CM binding (Kd = 120.6 μM) and the formation of low levels of amphiphilic α-helical structure (30.1%), with low levels of CM penetration (4.8 mN m-1) and lysis (36.4%). C-terminal deamidation had a variable influence on the antibacterial activity of M5-NH2, and in the case of S. aureus, loss of this structural moiety had no apparent effect on activity. The resistance of S. aureus to M5-NH2 isoforms appeared to be facilitated by the high level of charge carried by these peptides, as well as the density and distribution of this charge. In the case of P. aeruginosa, the activity of M5-NH2 was greatly reduced by C-terminal deamidation (MLC = 138.6 µM), primarily through decreased CM binding (Kd = 118.4 μM) and amphiphilic α-helix formation (39.6%) that led to lower levels of CM penetration (5.1 mN m-1) and lysis (39.0%).

First report on comprehensive genomic analysis of a multidrug-resistant Enterobacter asburiae isolated from diabetic foot infection from Bangladesh

Enterobacter asburiae (E. asburiae) is a gram-negative rod-shaped bacterium which has emerging significance as an opportunistic pathogen having high virulence pattern and drug resistant properties. In this study, we present the detailed analysis of the whole genome sequence of a multidrug-resistant (MDR) E. asburiae strain BDW1M3 from Bangladesh. The isolate was collected from an infected foot wound of a diabetic foot ulcer patient. Through sophisticated genomic techniques encompassing whole genome sequencing and in-depth bioinformatic analyses, this research unveils a profound understanding of the isolate's antimicrobial resistance patterns, virulence determinants, biosynthetic gene clusters, metabolic pathways and pathogenic potential. The isolate displayed resistance to Ampicillin, Fosfomycin, Cefoxitin, Tigecycline, Meropenem, Linezolid, Vancomycin antibiotics and demonstrated the capacity for biofilm formation. Several antimicrobial resistance genes such as blaACT-2,fosA2, baeR, qnrE2, vanA and numbers of virulence genes including ybaJ, csrA, barA, uvrY, pgaD, hlyD, hlyC, terC, purD were detected. Metal resistance genes investigation revealed the presence of cusCFBA operon system, and many other genes including zntA, zitB, czrB. Prophage region of Myoviridae was detected. Comparative genomics with 47 whole genome sequence (n = 47) shed light on the genetic diversity of E. asburiae strains from diverse sources and countries, with a notable observation that strains from both human and non-human origins exhibited significant pathogenicity potential, genomic and phylogenomic relations hinting at potential cross-species transmission. Pangenome analysis indicated toward an expanding pangenome of E. asburiae. Further research and in-depth comprehensive studies are required to investigate the prevalence of E. asburiae in Bangladesh and emphasize towards unraveling the bacterium's inherent pathogenic potential and the intricate molecular mechanisms that underlie its resistance traits and virulence properties.

Natural polymer nanofiber dressings for effective management of chronic diabetic wounds: A comprehensive review

Diabetic wounds present a chronic challenge in effective treatment. Natural polymer nanofiber dressings have emerged as a promising solution due to their impressive biocompatibility, biodegradability, safety, high specific surface area, and resemblance to the extracellular matrix. These qualities make them ideal materials with excellent biological properties and cost-effectiveness. Additionally, they can effectively deliver therapeutic agents, enabling diverse treatment effects. This review offers a comprehensive overview of natural polymer-based nanofibers in diabetic wound dressings. It examines the characteristics and challenges associated with diabetic wounds and the role of natural polymers in facilitating wound healing. The review highlights the preparation, mechanism, and applications of various functional dressings composed of natural polymer nanofibers. Furthermore, it addresses the main challenges and future directions in utilizing natural polymer nanofibers for diabetic wound treatment, providing valuable insights into effective wound management for diabetic patients.

Evaluation of Antibiotic-Loaded Bone Cement in Treatment of Infected Diabetic Foot: Systematic Review and Meta-Analysis

BACKGROUND

Diabetic foot ulcer (DFU) is a common and complex complication in patients with diabetes mellitus. The study of antibiotic-loaded bone cement for the treatment of infected diabetic foot is limited. We aimed to assess the efficacy of antibiotic-loaded bone cement for the treatment of infected diabetic foot.

METHODS

The MEDLINE, Embase, BIOSIS, the Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Knowledge databases were systematically searched up to May 2023 with no language restrictions. We assessed eligible studies for the efficacy of antibiotic-loaded bone cement for the treatment of infected diabetic foot. The standard mean differences (SMDs) or the risk ratios (RRs) were calculated for continuous or dichotomous data, respectively. Data were analysed using the Cochrane Collaboration's RevMan 5.0 software.

RESULTS

Nine articles with 565 patients were analysed in our meta-analysis. The wound healing time in ABC group was significantly shorter than that in the control group (SMD = -1.64, 95% CI -2.27 to -1.02 p < 0.00001, I2 = 88%). The ABC group had a significantly decreased number of debridements (SMD = -2.47, 95% CI -4.24 to -0.70, p < 0.00001, I2 = 95%). The pooled data showed no significant difference (RR = 0.41, 95% CI 0.12 to 1.39, p = 0.84, I2 = 0%).

CONCLUSION

This is the first meta-analysis comparing the efficacy of antibiotic-loaded bone cement for the treatment of infected diabetic foot. Antibiotic-loaded bone cement treatment significantly shortened the wound healing time and reduced the number of debridements without increasing the incidence of complications.

TRIAL REGISTRATION

PROSPERO CRD42023406017.

Protocol for a systematic review and meta-analysis of interventions aimed at delabeling low-risk penicillin allergies with consideration for sex and gender

BACKGROUND

Approximately, 10% of people report a penicillin allergy; however, more than 90% can safely undergo delabeling after a detailed history, oral challenge, or other investigations such as penicillin skin testing (PST). Although PST is the gold standard, the results can be heterogeneous, and awaiting specialist assessment may take an inordinate amount of time. Therefore, oral provocation challenge has become acceptable for individuals with low-risk penicillin allergy histories. There also appears to be an association with increased prevalence of adverse drug reaction reporting in female individuals, which may translate to penicillin allergy prevalence; however, the evidence has not been assessed through a sex and gender lens. This systematic review will identify and synthesize the findings from studies that report measures of effectiveness and safety of interventions aimed at delabeling penicillin allergies in low-risk individuals. Information related to sex and gender will be extracted, where available, to understand potential differences in allergy reporting and patient outcomes.

METHODS

The Cochrane Handbook for Systematic Reviews of Interventions and the Centre for Review and Dissemination's Guidance for Undertaking Reviews in Health Care will be used as frameworks for conducting this systematic review. The literature search will be conducted by a medical librarian (B. M. M.) and will consist of a search strategy to identify and retrieve published studies that meet our inclusion criteria. Studies that require penicillin skin testing (PST) as a step prior to other interventions will be excluded. Integrated knowledge translation involving co-design was carried out for this systematic review protocol creation. Data extraction will be conducted at four levels: (1) study level, (2) patient level, (3) intervention level, and (4) outcome level. A narrative descriptive synthesis of results and risk of bias of all included studies will be provided, and, if relevant, a meta-analysis will be performed.

DISCUSSION

The dissemination of findings from this knowledge synthesis to various stakeholders is intended to inform on options for evidence-based interventions to aid in delabeling penicillin allergies in individuals with a low risk of experiencing a hypersensitivity reaction. Detailed reporting on the characteristics of delabeling interventions as well as the effectiveness of similar interventions will benefit policy makers considering the implementation of a penicillin allergy delabeling protocol. Additionally, findings from this systematic review will report on the current evidence regarding the role of sex and gender in both the prevalence and outcomes associated with the presence of penicillin allergies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022336457.

Impact of Silver Dressings on Wound Healing Rate in Patients with Lower Extremity Ulcers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

The ulcers of lower extremities, both venous and diabetic, impose a massive burden on sufferers globally. This meta-analysis evaluates the efficacy of silver dressings in improving healing rate of these ulcers.

METHODS

We carried out comprehensive searches in PubMed, Embase, Web of Science, the Cochrane Library, and China National Knowledge Internet (CNKI) up to March 2024. Two reviewers independently screened the study and extracted data. While the primary outcome was wound healing rate, secondary outcomes included wound healing area and recurrence rate. Data were analyzed using Stata 16.0 software.

RESULTS

A total of 18 studies involving 1,825 participants were included. Silver dressings demonstrated statistically significant effects in improving healing rates for diabetic foot ulcers (DFUs) (OR 2.14, 95% CI: 1.52, 3.00, p = 0.00), whereas the effects were not statistically significant for venous leg ulcers (VLUs) (OR 1.32, 95% CI: 0.97, 1.78, p = 0.07). Silver dressings also reduced ulcer area by 27.44 cm2 (95% CI: 6.96-47.92) and recurrence rate by 45% (95% CI: 0.11-1.79). Subgroup analysis revealed that the Asia-Pacific region and treatments of 6 weeks or less exhibited higher healing rates than their respective counterparts, although there was no statistical significance.

CONCLUSIONS

This study indicated a statistically significant benefit of the treatment for DFU. However, the effect on VLU, though positive, did not reach statistical significance. This distinction should be considered in clinical application and further research.

OBJECTIVE

The ulcers of lower extremities, both venous and diabetic, impose a massive burden on sufferers globally. This meta-analysis evaluates the efficacy of silver dressings in improving healing rate of these ulcers.

METHODS

We carried out comprehensive searches in PubMed, Embase, Web of Science, the Cochrane Library, and China National Knowledge Internet (CNKI) up to March 2024. Two reviewers independently screened the study and extracted data. While the primary outcome was wound healing rate, secondary outcomes included wound healing area and recurrence rate. Data were analyzed using Stata 16.0 software.

RESULTS

A total of 18 studies involving 1,825 participants were included. Silver dressings demonstrated statistically significant effects in improving healing rates for diabetic foot ulcers (DFUs) (OR 2.14, 95% CI: 1.52, 3.00, p = 0.00), whereas the effects were not statistically significant for venous leg ulcers (VLUs) (OR 1.32, 95% CI: 0.97, 1.78, p = 0.07). Silver dressings also reduced ulcer area by 27.44 cm2 (95% CI: 6.96-47.92) and recurrence rate by 45% (95% CI: 0.11-1.79). Subgroup analysis revealed that the Asia-Pacific region and treatments of 6 weeks or less exhibited higher healing rates than their respective counterparts, although there was no statistical significance.

CONCLUSIONS

This study indicated a statistically significant benefit of the treatment for DFU. However, the effect on VLU, though positive, did not reach statistical significance. This distinction should be considered in clinical application and further research.

Greener healing: sustainable nanotechnology for advanced wound care

Wound healing involves a carefully regulated sequence of events, encompassing pro-inflammatory and anti-inflammatory stages, tissue regeneration, and remodeling. However, in individuals with diabetes, this process gets disrupted due to dysregulation caused by elevated glucose levels and pro-inflammatory cytokines in the bloodstream. Consequently, the pro-inflammatory stage is prolonged, while the anti-inflammatory phase is delayed, leading to impaired tissue regeneration and remodeling with extended healing time. Furthermore, the increased glucose levels in open wounds create an environment conducive to microbial growth and tissue sepsis, which can escalate to the point of limb amputation. Managing diabetic wounds requires meticulous care and monitoring due to the lack of widely available preventative and therapeutic measures. Existing clinical interventions have limitations, such as slow recovery rates, high costs, and inefficient drug delivery methods. Therefore, exploring alternative avenues to develop effective wound-healing treatments is essential. Nature offers a vast array of resources in the form of secondary metabolites, notably polyphenols, known for their antimicrobial, anti-inflammatory, antioxidant, glucose-regulating, and cell growth-promoting properties. Additionally, nanoparticles synthesized through environmentally friendly methods hold promise for wound healing applications in diabetic and non-diabetic conditions. This review provides a comprehensive discussion and summary of the potential wound-healing abilities of specific natural polyphenols and their nanoparticles. It explores the mechanisms of action underlying their efficacy and presents effective formulations for promoting wound-healing activity.

Local Management for Diabetic Foot Ulcers: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This study evaluated the efficacy of various local management strategies for diabetic foot ulcers (DFUs).

BACKGROUND

Several surgical and non-surgical local interventional approaches are available for the treatment of DFUs. The comparative effectiveness of different treatments is unknown, and it remains unclear which approach is the optimal choice for DFUs treatment due to limited direct comparisons.

METHODS

We did a systematic review and meta-analysis to select the optimal approach to DFUs local management. We searched Medline, Embase, Web of Science, and ClinicalTrials.gov from inception to September 1, 2023, to identify relevant randomized controlled trials (RCTs). We analysed data by pairwise meta-analyses with a random-effects model. A network meta-analysis using the surface under the cumulative ranking curve (SUCRA) was performed to evaluate the comparative efficacy of different interventional approaches in the early (within 12 wk) and late stages (over 12 wk).

RESULTS

141 RCTs involving 14076 patients and exploring 14 interventional strategies were eligible for inclusion. Most studies (102/141) had at least one risk-of-bias dimension. Good consistency was observed during the analysis. Local pairwise comparisons demonstrated obvious differences in the early-stage healing rate and early- and late-stage healing times, while no significant difference in the late-stage healing rate or adverse events were noted. SUCRAs identified the standard of care (SOC) + decellularized dressing (DD), off-loading (OL), and autogenous graft (AG) as the three most effective interventions within 12 weeks for both healing rate (97%, mean rank: 1.4; 90%, mean rank: 2.3; 80.8%, mean rank: 3.5, respectively) and healing time (96.7%, mean rank: 1.4; 83.0%, mean rank: 3.0; 76.8%, mean rank: 3.8, respectively). After 12 weeks, local drug therapy (LDT) (89.5%, mean rank: 2.4) and OL (82.4%, mean rank: 3.3) ranked the highest for healing rate, and OL (100.0%, mean rank: 1.0) for healing time. With respect to adverse events, moderate and high risks were detected in the SOC + DD (53.7%, mean rank: 7.0) and OL (24.4%, mean rank: 10.8) groups, respectively.

CONCLUSION

The findings suggest that OL provided considerable benefits for DFU healing in both the early and late stages, but the high risk of adverse events warrants caution. SOC+DD may be the preferred option in the early stages, with an acceptable risk of adverse events.

Dual Drug-Loaded Coaxial Nanofiber Dressings for the Treatment of Diabetic Foot Ulcer

Introduction

Diabetes mellitus is frequently associated with foot ulcers, which pose significant health risks and complications. Impaired wound healing in diabetic patients is attributed to multiple factors, including hyperglycemia, neuropathy, chronic inflammation, oxidative damage, and decreased vascularization.

Rationale

To address these challenges, this project aims to develop bioactive, fast-dissolving nanofiber dressings composed of polyvinylpyrrolidone loaded with a combination of an antibiotic (moxifloxacin or fusidic acid) and anti-inflammatory drug (pirfenidone) using electrospinning technique to prevent the bacterial growth, reduce inflammation, and expedite wound healing in diabetic wounds.

Results

The fabricated drug-loaded fibers exhibited diameters of 443 ± 67 nm for moxifloxacin/pirfenidone nanofibers and 488 ± 92 nm for fusidic acid/pirfenidone nanofibers. The encapsulation efficiency, drug loading and drug release studies for the moxifloxacin/pirfenidone nanofibers were found to be 70 ± 3% and 20 ± 1 µg/mg, respectively, for moxifloxacin, and 96 ± 6% and 28 ± 2 µg/mg, respectively, for pirfenidone, with a complete release of both drugs within 24 hours, whereas the fusidic acid/pirfenidone nanofibers were found to be 95 ± 6% and 28 ± 2 µg/mg, respectively, for fusidic acid and 102 ± 5% and 30 ± 2 µg/mg, respectively, for pirfenidone, with a release rate of 66% for fusidic acid and 80%, for pirfenidone after 24 hours. The efficacy of the prepared nanofiber formulations in accelerating wound healing was evaluated using an induced diabetic rat model. All tested formulations showed an earlier complete closure of the wound compared to the controls, which was also supported by the histopathological assessment. Notably, the combination of fusidic acid and pirfenidone nanofibers demonstrated wound healing acceleration on day 8, earlier than all tested groups.

Conclusion

These findings highlight the potential of the drug-loaded nanofibrous system as a promising medicated wound dressing for diabetic foot applications.

The use of antimicrobial dressings for the management of diabetic foot ulcers: A survey of podiatrists in Aotearoa New Zealand

INTRODUCTION

Diabetic foot ulcers (DFUs) are commonly contaminated with pathogenic organisms and precede most diabetes-related amputations. Antimicrobial dressings are used in the treatment of DFUs; however, recent guidelines do not support their use. There are no data describing the experience of antimicrobial dressing use among podiatrists in Aotearoa New Zealand (AoNZ). This study aimed to (i) determine which antimicrobial dressings podiatrists in AoNZ use for the management of diabetic foot ulcers; and (ii) determine what factors influence AoNZ podiatrists' use of antimicrobial dressing when managing DFUs.

METHODS

An anonymous cross-sectional web-based survey was undertaken. Participants were AoNZ registered podiatrists who managed DFUs in their practice. The survey included questions relating to personal and professional demographic characteristics and DFU management and dressing practices. Descriptive statistics were computed to address the research aims.

RESULTS

Responses from 43 AoNZ podiatrists were included. Participants reported both cadexomer iodine and silver dressings were the most common antimicrobial dressings used, with honey dressings being the least frequently used. The most influential factors in choosing antimicrobial dressings when managing DFUs were the presence of current infection, ulcer exudate and ability to prevent future infection. The least influential factors in choosing antimicrobial dressings when managing DFUs were patient preferences, cost of dressings and comfort of dressing/pain on removal.

CONCLUSIONS

AoNZ podiatrists managing DFUs primarily use antimicrobial dressings containing cadexomer iodine or silver as active ingredients, while lower-cost options, such as honey and povidone iodine are less often used. Current recommendations highlight the lack of evidence to support positive outcomes from any particular antimicrobial dressing over another and advocate that exudate control, comfort and cost be prioritised in decision-making. As cost has been an increasing burden to our healthcare funding, clinicians and organisations may consider this before purchasing and stocking expensive dressings.

Brazilian Society of Angiology and Vascular Surgery 2023 guidelines on the diabetic foot

The diabetic foot interacts with anatomical, vascular, and neurological factors that challenge clinical practice. This study aimed to compile the primary scientific evidence based on a review of the main guidelines, in addition to articles published on the Embase, Lilacs, and PubMed platforms. The European Society of Cardiology system was used to develop recommendation classes and levels of evidence. The themes were divided into six chapters (Chapter 1 - Prevention of foot ulcers in people with diabetes; Chapter 2 - Pressure relief from foot ulcers in people with diabetes; Chapter 3 -Classifications of diabetic foot ulcers; Chapter 4 - Foot and peripheral artery disease; Chapter 5 - Infection and the diabetic foot; Chapter 6 - Charcot's neuroarthropathy). This version of the Diabetic Foot Guidelines presents essential recommendations for the prevention, diagnosis, treatment, and follow-up of patients with diabetic foot, offering an objective guide for medical practice.

Topical pravibismane as adjunctive therapy for moderate or severe diabetic foot infections: A phase 1b randomized, multicenter, double-blind, placebo-controlled trial

This Phase 1b study was designed to evaluate the safety and efficacy of pravibismane, a novel broad-spectrum topical anti-infective, in managing moderate or severe chronic diabetic foot ulcer (DFU) infections. This randomized, double-blind, placebo-controlled, multicenter study consisted of 39 individuals undergoing pravibismane treatment and 13 individuals in the placebo group. Assessment of safety parameters included clinical observations of tolerability and pharmacokinetics from whole blood samples. Pravibismane was well-tolerated and exhibited minimal systemic absorption, as confirmed by blood concentrations that were below the lower limit of quantitation (0.5 ng/mL) or in the low nanomolar range, which is orders of magnitude below the threshold of pharmacological relevance for pravibismane. Pravibismane treated subjects showed approximately 3-fold decrease in ulcer size compared to the placebo group (85% vs. 30%, p = 0.27). Furthermore, the incidence of ulcer-related lower limb amputations was approximately 6-fold lower (2.6%) in the pooled pravibismane group versus 15.4% in the placebo group (p = 0.15). There were no treatment emergent or serious adverse events related to study drug. The initial findings indicate that topical pravibismane was safe and potentially effective treatment for improving recovery from infected chronic ulcers by reducing ulcer size and facilitating wound healing in infected DFUs (ClinicalTrials.gov Identifier NCT02723539).

IWGDF/IDSA guidelines on the diagnosis and treatment of diabetes-related foot infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Interventions in the management of diabetes-related foot infections: A systematic review

The optimal approaches to managing diabetic foot infections remain a challenge for clinicians. Despite an exponential rise in publications investigating different treatment strategies, the various agents studied generally produce comparable results, and high-quality data are scarce. In this systematic review, we searched the medical literature using the PubMed and Embase databases for published studies on the treatment of diabetic foot infections from 30 June 2018 to 30 June 2022. We combined this search with our previous literature search of a systematic review performed in 2020, in which the infection committee of the International Working Group on the Diabetic Foot searched the literature until June 2018. We defined the context of the literature by formulating clinical questions of interest, then developing structured clinical questions (Patients-Intervention-Control-Outcomes) to address these. We only included data from controlled studies of an intervention to prevent or cure a diabetic foot infection. Two independent reviewers selected articles for inclusion and then assessed their relevant outcomes and methodological quality. Our literature search identified a total of 5,418 articles, of which we selected 32 for full-text review. Overall, the newly available studies we identified since 2018 do not significantly modify the body of the 2020 statements for the interventions in the management of diabetes-related foot infections. The recent data confirm that outcomes in patients treated with the different antibiotic regimens for both skin and soft tissue infection and osteomyelitis of the diabetes-related foot are broadly equivalent across studies, with a few exceptions (tigecycline not non-inferior to ertapenem [±vancomycin]). The newly available data suggest that antibiotic therapy following surgical debridement for moderate or severe infections could be reduced to 10 days and to 3 weeks for osteomyelitis following surgical debridement of bone. Similar outcomes were reported in studies comparing primarily surgical and predominantly antibiotic treatment strategies in selected patients with diabetic foot osteomyelitis. There is insufficient high-quality evidence to assess the effect of various recent adjunctive therapies, such as cold plasma for infected foot ulcers and bioactive glass for osteomyelitis. Our updated systematic review confirms a trend to a better quality of the most recent trials and the need for further well-designed trials to produce higher quality evidence to underpin our recommendations.

Formulation and characterization of polyvinyl alcohol/chitosan composite nanofiber co-loaded with silver nanoparticle & luliconazole encapsulated poly lactic-co-glycolic acid nanoparticle for treatment of diabetic foot ulcer

Chronic wounds are prone to fungal infections, possess a significant challenge, and result in substantial mortality. Diabetic wounds infected with Candida strains are extremely common. It can create biofilm at the wound site, which can lead to antibiotic resistance. As a result, developing innovative dressing materials that combat fungal infections while also providing wound healing is a viable strategy to treat infected wounds and address the issue of antibiotic resistance. Present work proposed anti-infective dressing material for the treatment of fungal strains Candida-infected diabetic foot ulcer (DFU). The nanofiber was fabricated using polyvinyl Alcohol/chitosan as hydrogel base and co-loaded with silver nanoparticles (AgNP) and luliconazole-nanoparticles (LZNP) nanoparticles, prepared using PLGA. Fabricated nanofibers had pH close to target area and exhibited hydrophilic surface suitable for adhesion to wound area. The nanofibers showed strong antifungal and antibiofilm properties against different strains of Candida; mainly C. albicans, C. auris, C. krusei, C. parapsilosis and C. tropicalis. Nanofibers exhibited excellent water retention potential and water vapour transmission rate. The nanofibers had sufficient payload capacity towards AgNP and LZNP, and provided controlled release of payload, which was also confirmed by in-vivo imaging. In-vitro studies confirmed the biocompatibility and enhanced proliferation of Human keratinocytes cells (HaCaT). In-vivo studies showed accelerated wound closure by providing ant-infective action, supporting cellular proliferation and improving blood flow, all collectively contributing in expedited wound healing.

A Novel Potential Treatment for Diabetic Foot Ulcers and Non-Healing Ulcers - Case Series

Introduction: Appropriate care and treatment of a wound is the need of the hour whether it is an infected or a non-infected wound. If wound healing is delayed for some reason, it leads to serious complications and further increases the hospital stay and cost of treatment. Herein, we describe a novel antimicrobial wound dressing formulation (VG111), with an objective to generate the preliminary data showing the distinct advantages in various types of wounds.

Method: This case series involved the treatment of acute cases of wounds or chronic wounds that did not respond well to conventional wound healing treatments with VG111 in patients with different etiologies. Thirteen cases of patients that included patients with diabetes, pressure ulcers, burns, trauma, and others treated with VG111 showed rapid wound healing in all the cases, even obviating the need for a graft when complete skin regeneration occurred.

Result: This was illustrated by clearing of the wound infections, reduction/disappearance of the exudate, appearance of intense granulation, epithelialization, and anti-biofilm activity followed by complete wound closure. This VG111 precludes the need for systemic antimicrobial agents in localized infections and therefore, this single agent is an attempt to address the limitations and the drawbacks of the available products.

Conclusion: Despite patients belonging to the old age group and having comorbidities like diabetes, still VG111 showed effective rapid wound healing, and that too without any scar formation in hardto- heal, infected, and non-infected wounds.

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Extracellular vesicle biopotentiated hydrogels for diabetic wound healing: The art of living nanomaterials combined with soft scaffolds

Diabetic wounds (DWs) pose a major challenge for the public health system owing to their high incidence, complex pathogenesis, and long recovery time; thus, there is an urgent need to develop innovative therapies to accelerate the healing process of diabetic wounds. As natural nanovesicles, extracellular vesicles (EVs) are rich in sources with low immunogenicity and abundant nutritive molecules and exert potent therapeutic effects on diabetic wound healing. To avoid the rapid removal of EVs, a suitable delivery system is required for their controlled release. Owing to the advantages of high porosity, good biocompatibility, and adjustable physical and chemical properties of hydrogels, EV biopotentiated hydrogels can aid in achieving precise and favorable therapy against diabetic wounds. This review highlights the different design strategies, therapeutic effects, and mechanisms of EV biopotentiated hydrogels. We also discussed the future challenges and opportunities of using EV biopotentiated hydrogels for diabetic wound healing.

Microbiota-derived imidazole propionate inhibits type 2 diabetic skin wound healing by targeting SPNS2-mediated S1P transport

Imidazole propionate (ImP) is a recently discovered metabolite of T2DM-related gut microbiota. The effect of ImP on T2DM wound healing has not been studied yet. In this research, the changes of ImP-producing bacteria on the skin are firstly evaluated. 16sRNA sequencing results showed that the abundance of ImP-producing bacteria-Streptococcus in the intestine and skin of T2DM mice is significantly increased. Animal experiments show that ImP can inhibit the process of wound healing and inhibit the formation of blood vessels in the process of wound healing. Molecular mechanism research results show that ImP can inhibit S1P secretion mediated by SPNS2, and inhibit the activation of Rho signaling pathway, thereby affecting the angiogenesis process of HUVEC cells. This work also provides a potential drug HMPA that promotes T2DM wound healing.

Exploring the contribution of pro-inflammatory cytokines to impaired wound healing in diabetes

BACKGROUND

Impaired wound healing is the most common and significant complication of Diabetes. While most other complications of Diabetes have better treatment options, diabetic wounds remain a burden as they can cause pain and suffering in patients. Wound closure and repair are orchestrated by a sequence of events aided by the release of pro-inflammatory cytokines, which are dysregulated in cases of Diabetes, making the wound environment unfavorable for healing and delaying the wound healing processes. This concise review provides an overview of the dysregulation of pro-inflammatory cytokines and offers insights into better therapeutic outcomes.

PURPOSE OF REVIEW

Although many therapeutic approaches have been lined up nowadays to treat Diabetes, there are no proper treatment modalities proposed yet in treating diabetic wounds due to the lack of understanding about the role of inflammatory mediators, especially Pro-inflammatory mediators- Cytokines, in the process of Wound healing which we mainly focus on this review.

RECENT FINDINGS

Although complications of Diabetes mellitus are most reported after years of diagnosis, the most severe critical complication is impaired Wound Healing among Diabetes patients. Even though Trauma, Peripheral Artery Disease, and Peripheral Neuropathy are the leading triggering factors for the development of ulcerations, the most significant issue contributing to the development of complicated cutaneous wounds is wound healing impairment. It may even end up with amputation. Newer therapeutic approaches such as incorporating the additives in the present dressing materials, which include antimicrobial molecules and immunomodulatory cytokines is of better therapeutic value.

SUMMARY

The adoption of these technologies and the establishment of novel therapeutic interventions is difficult since there is a gap in terms of a complete understanding of the pathophysiological mechanisms at the cellular and molecular level and the lack of data in terms of the assessment of safety and bioavailability differences in the individuals' patients. The target-specific pro-inflammatory cytokines-based therapies, either by upregulation or downregulation of them, will be helpful in the wound healing process and thereby enhances the Quality of life in patients, which is the goal of drug therapy.

Effectiveness of Topical Sucralfate in the Management of Diabetic Foot Ulcers: An Open-Labeled Randomized Study

INTRODUCTION

Diabetic foot ulcer (DFU) is a major cause of lower limb amputations. Many treatment recommendations have been proposed. This study was conducted to evaluate the effectiveness of topical sucralfate when combined with mupirocin ointment, in the treatment of diabetic foot ulcer in comparison to topical mupirocin alone, in terms of healing rates.

METHODS

This open-labeled randomized study was conducted on 108 patients to evaluate the effectiveness of topical sucralfate and mupirocin combination, compared to topical mupirocin alone. The patients were administered the same parenteral antibiotic, and wounds were subjected to daily dressing. The healing rates (determined by the percentage reduction in wound area) in the two groups were calculated. The mean healing rates in both groups were expressed in percentage and compared using the Student's t-test.

RESULTS

A total of 108 patients were included in the study. Male-to-female ratio was 3:1. The incidence of diabetic foot was the highest (50.9%) in the age group of 50-59 years. The mean age of the study population was 51 years. The incidence of diabetic foot ulcers was highest in the months of July-August (42%). A total of 71.2% patients had random blood sugar levels between 150-200 mg/dL, and 72.2% patients had diabetes for five to 10 years. The mean±standard deviation (SD) of the healing rates in the sucralfate and mupirocin combination group and the control group were 16.2±7.3% and 14.5±6.6%, respectively. Comparison of the means by Student's t-test failed to show a statistical difference in healing rates between the two groups (p=0.201).

CONCLUSION

We concluded that the addition of topical sucralfate does not show any obvious benefits in terms of healing rates in diabetic foot ulcers as compared to mupirocin alone.

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

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

Role of M1 macrophages in diabetic foot ulcers and related immune regulatory mechanisms

Objectives: Diabetes foot ulcers (DFUs) are characterized by immune infiltration of M1 macrophages observed in foot skin, in which immune-associated genes (IRGs) play a prominent role. The precise expression of IRGs as well as any possible regulatory mechanisms that could be present in DFUs is yet unknown. Methods: The sequencing data of single-cell RNA (scRNA) in the foot skin of patients with DFUs were analyzed, screening out the cluster marker genes of foot skin obtained from the ImmPort database. IRG activity was assessed with the AUCell software package. The IRGs of DFUs were explored by analyzing the batch sequencing dataset of DFU skin tissue. HumanTFDB was adopted to identify relevant regulatory transcription factors (TFs). The STRING dataset was used to build the main TF protein-protein interaction networks. WB and immunofluorescence methods were used to verify M1 macrophage-related immune regulators. Results: There were 16 clusters found: SMC1, fibro, t-lympho, he fibro, vasendo, baselkera, diffkera, SMC2, M1 macro, M2 macro, sweet/seba, B-Lympho, Melanio, lymphendo, plasma, and Schwann. M1 and M2 macrophages both had considerably higher AUC ratings than patients with DFUs compared to other sub-populations of cells. The proportion of M1 macrophages was the highest in the non-healing group. According to scRNA analysis and batch sequencing data by GO and KEGG, DEGs were enriched in immune response. Some 106 M1 macro-IRGs were finally identified and 25 transcription factors were revealed as associated with IRG expression. The PPI network indicated NFE2L2, REL, ETV6, MAF, and NF1B as central transcription factors. Conclusion: Based on the bio-informatics analysis of scRNA and high-throughput sequencing data, we concluded that M1 macrophages may serve as the influencing factor of DFUs' non-union. In addition, NFE2L2 could be involved in the regulation of IRG expression within M1 macrophages.

[Diabetic neuropathy and diabetic foot syndrome (update 2023)]

These are the guidelines for diagnosis and treatment of diabetic neuropathy and diabetic foot.The position statement summarizes characteristic clinical symptoms and techniques for diagnostic assessment of diabetic neuropathy, including the complex situation of the diabetic foot syndrome. Recommendations for the therapeutic management of diabetic neuropathy, especially for the control of pain in sensorimotor neuropathy, are provided. The needs to prevent and treat diabetic foot syndrome are summarized.

Recent advances in responsive hydrogels for diabetic wound healing

Poor wound healing after diabetes mellitus remains a challenging problem, and its pathophysiological mechanisms have not yet been fully elucidated. Persistent bleeding, disturbed regulation of inflammation, blocked cell proliferation, susceptible infection and impaired tissue remodeling are the main features of diabetic wound healing. Conventional wound dressings, including gauze, films and bandages, have a limited function. They generally act as physical barriers and absorbers of exudates, which fail to meet the requirements of the whol diabetic wound healing process. Wounds in diabetic patients typically heal slowly and are susceptible to infection due to hyperglycemia within the wound bed. Once bacterial cells develop into biofilms, diabetic wounds will exhibit robust drug resistance. Recently, the application of stimuli-responsive hydrogels, also known as "smart hydrogels", for diabetic wound healing has attracted particular attention. The basic feature of this system is its capacities to change mechanical properties, swelling ability, hydrophilicity, permeability of biologically active molecules, etc., in response to various stimuli, including temperature, potential of hydrogen (pH), protease and other biological factors. Smart hydrogels can improve therapeutic efficacy and limit total toxicity according to the characteristics of diabetic wounds. In this review, we summarized the mechanism and application of stimuli-responsive hydrogels for diabetic wound healing. It is hoped that this work will provide some inspiration and suggestions for research in this field.

Advances and perspective on animal models and hydrogel biomaterials for diabetic wound healing

Diabetic wounds are a common complication in diabetes patients. Due to peripheral nerve damage and vascular dysfunction, diabetic wounds are prone to progress to local ulcers, wound gangrene and even to require amputation, bringing huge psychological and economic burdens to patients. However, the current treatment methods for diabetic wounds mainly include wound accessories, negative pressure drainage, skin grafting and surgery; there is still no ideal treatment to promote diabetic wound healing at present. Appropriate animal models can simulate the physiological mechanism of diabetic wounds, providing a basis for translational research in treating diabetic wound healing. Although there are no animal models that can fully mimic the pathophysiological mechanisms of diabetic wounds in humans, it is vital to explore animal simulation models used in basic research and preclinical studies of diabetic wounds. In addition, hydrogel materials are regarded as a promising treatment for diabetic wounds because of their good antimicrobial activity, biocompatibility, biodegradation and appropriate mechanical properties. Herein, we review and discuss the different animal models used to investigate the pathological mechanisms of diabetic wounds. We further discuss the promising future application of hydrogel biomaterials in diabetic wound healing.

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.

Modified poly(L-lysine)-based structures as novel antimicrobials for diabetic foot infections, an in-vitro study

Background: Wound infections occur as sequelae to skin trauma and cause significant hospitalizations, morbidity and mortality. Skin traumas arise more frequently in those with diabetes or cardiovascular disease and in these settings, may be chronic with poorer outcomes including lower limb amputation. Treatment of chronic wound infection is challenging due to antibiotic resistance and biofilm formation by bacteria including S. aureus and P. aeruginosa, which are among the most frequent causative pathogens. Managing these challenging infections requires new molecules and modalities. Methods: We evaluated antimicrobial and anti-biofilm activity of star-shaped poly(L-lysine) (PLL) polymers against S. aureus and P. aeruginosa strains and clinical isolates recovered from wounds including diabetic foot wounds (DFW) in a Dublin Hospital in 2019. A star-shaped PLL polypeptide series, specifically G2(8)PLL ₂₀, G3(16)PLL ₁₀, G4(32)PLL ₅ with variation in polypeptide chain length and arm-multiplicity, were compared to a linear peptide, PLL ₁₆₀ with equivalent number of lysine residues. Results: All PLLs, including the linear polypeptide, were bactericidal at 1μM against S. aureus 25923 and P. aeruginosa PAO1, with log reduction in colony forming units/ml between 2.7-3.6. PLL ₁₆₀ demonstrated similar killing potency against 20 S. aureus and five P. aeruginosa clinical isolates from DFW, mean log reductions: 3.04 ± 0.16 and 3.96 ± 0.82 respectively after 1 hour incubation. Potent anti-biofilm activity was demonstrated against S. aureus 25923 but for clinical isolates, low to moderate loss of biofilm viability was shown using PLL ₁₆₀ and G3(16)PLL ₁₀ at 50 μM ( S. aureus) and 200 μM ( P. aeruginosa) with high inter-isolate variability . In the star-shaped architecture, antimicrobial activity was retained with incorporation of 5-mer hydrophobic amino-acid modifications to the arms of the polypeptides (series G3(16)PLL ₂₀-coPLT ₅, G3(16)PLL ₂₀-coPLI ₅, G3(16)PLL ₂₀-coPLP ₅). Conclusion: These polypeptides offer structural flexibility for clinical applications and have potential for further development, particularly in the setting of diabetic foot and other chronic wound infections.

Alternative Approaches for the Management of Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) represent a growing public health problem. The emergence of multidrug-resistant (MDR) bacteria is a complication due to the difficulties in distinguishing between infection and colonization in DFU. Another problem lies in biofilm formation on the skin surface of DFU. Biofilm is an important pathophysiology step in DFU and may contribute to healing delays. Both MDR bacteria and biofilm producing microorganism create hostile conditions to antibiotic action that lead to chronicity of the wound, followed by infection and, in the worst scenario, lower limb amputation. In this context, alternative approaches to antibiotics for the management of DFU would be very welcome. In this review, we discuss current knowledge on biofilm in DFU and we focus on some new alternative solutions for the management of these wounds, such as antibiofilm approaches that could prevent the establishment of microbial biofilms and wound chronicity. These innovative therapeutic strategies could replace or complement the classical strategy for the management of DFU to improve the healing process.

Stimulation of Healing of Non-Infected Stagnated Diabetic Wounds by Copper Oxide-Impregnated Wound Dressings

Background and Objective: Copper, a wide spectrum biocide, also plays a key role in angiogenesis and wound healing. Antibacterial wound dressings impregnated with copper oxide microparticles (COD) have been recently cleared by the U.S. FDA and other regulatory bodies for the treatment of acute and chronic wounds, including diabetic wounds. Our objective was to evaluate the capacity of COD in stimulating the healing of non-infected stagnated wounds in diabetic patients initially treated with standard of care (SOC) dressings. Materials and Methods: The trial was divided into the three following phases: 1–2 weeks of screening, during which the patients were treated with SOC dressings; 4 weeks of treatment, during which the COD was applied twice weekly; and 2 weeks of follow-up, during which the patients were again treated with SOC dressings. The wound conditions and sizes were assessed by clinical evaluation and a wound imaging artificial intelligence system. Results: Following 1 month of COD treatment, there was a clear reduction in the mean wound area (53.2%; p = 0.003), an increase in granulation tissue (43.37; p < 0.001), and a reduction in fibrins (47.8%; p = 0.002). In patients with non-weight-bearing wounds, the reduction in wound size was even more dramatic (66.9%; p < 0.001). Conclusions: The results of this study, showing a statistically significant influence of COD on wound healing of hard-to-heal wounds in diabetic patients, strongly supports the notion that copper oxide-impregnated dressings enhance wound healing directly. Further larger controlled studies should be conducted to substantiate our findings.

Experimental and Theoretical Screening for Green Solvents Improving Sulfamethizole Solubility

Solubility enhancement of poorly soluble active pharmaceutical ingredients is of crucial importance for drug development and processing. Extensive experimental screening is limited due to the vast number of potential solvent combinations. Hence, theoretical models can offer valuable hints for guiding experiments aimed at providing solubility data. In this paper, we explore the possibility of applying quantum-chemistry-derived molecular descriptors, adequate for development of an ensemble of neural networks model (ENNM), for solubility computations of sulfamethizole (SMT) in neat and aqueous binary solvent mixtures. The machine learning procedure utilized information encoded in σ-potential profiles computed using the COSMO-RS approach. The resulting nonlinear model is accurate in backcomputing SMT solubility and allowed for extensive screening of green solvents. Since the experimental characteristics of SMT solubility are limited, the data pool was extended by new solubility measurements in water, five neat organic solvents (acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, and methanol), and their aqueous binary mixtures at 298.15, 303.15, 308.15, and 313.15 K. Experimentally determined order of decreasing SMT solubility in neat solvents is the following: N,N-dimethylformamide > dimethyl sulfoxide > methanol > acetonitrile > 1,4dioxane >> water, in all studied temperatures. Similar trends are observed for aqueous binary mixtures. Since N,N-dimethylformamide is not considered as a green solvent, the more acceptable replacers were searched for using the developed model. This step led to the conclusion that 4-formylmorpholine is a real alternative to N,N-dimethylformamide, fulfilling all requirements of both high dissolution potential and environmental friendliness.

Role of an acidic environment in the treatment of diabetic foot infections: A review

Management of diabetic foot ulcers is the biggest challenge to the clinician, as conventional antibiotic therapies and local wound care have their own limitations. They are not effective for control of infections and promotion of healing because of cytotoxic effects. In view of cytotoxicity of routinely used topical antiseptic agents, this article focuses on the search of an ideal topical antiseptic agent that is safe and effective in controlling infectious agents and also in promoting the healing process. This review focuses on the use of various acids such as citric, acetic, hyaluronic, and hypochlorous acids as topical agents in diabetic foot infections. This article also focuses on the different roles of acids in the treatment of diabetic foot infections.

Analytical Method Development and Validation for Simultaneous Determination of Simvastatin and Mupirocin Using Reverse-Phase High-pressure Liquid Chromatographic Method

Objectives

This study was aimed to develop and validate the use of reverse-phase high pressure liquid chromatographic method for the estimation of simvastatin (SIM) and mupirocin (MUP) simultaneously.

Materials and Methods

The chromatographic method developed is optimized for flow rate with the column, solvent, and buffer used and mobile phase ratio, molarity, and pH. The validation of the optimized method and the forced degradation studies of both drugs (under acidic, alkaline, oxidation, heat, light, and neutral conditions) were conducted following the The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines.

Results

Kromasil C18 column (250 mm × 4.6 mm, 5 µm) with ultraviolet detection at 224 nm and acetonitrile/phosphate buffer (30 mM, 70:30 v/v, pH 3.5; adjustment done using orthophosphoric acid) as mobile phase at a flow rate of 1.1 mL/min were observed to provide a good resolution for MUP and SIM at retention times of 2.32±0.008 and 13.55±0.254 min, respectively, with high accuracy (percent recovery was 99.69±0.82 for MUP and 101.10±0.02 for SIM) and linearity in the range of 5-30 µg/mL (r²: 0.9969 for MUP and r²: 0.9959 for SIM). The diagnostic limit and the lower limit of determination were 0.771±0.234 and 2.338±0.246 μg/mL for MUP and 0.595±0.282 and 1.803±0.334 µg/mL for SIM, respectively. The validated method was used to understand the degradation behavior of both drugs after the forced degradation studies.

Conclusion

The analytical method developed is determined to be specific, sensitive, precise, and accurate for the estimation of MUP and SIM simultaneously in the combined dosage form.

Towards User-Oriented Recommendations for Local Therapy of Leg and Foot Ulcers-An Update of a S3-German Guideline

Background: The German S3- guideline on local therapy of leg ulcers and diabetic foot ulcers is in the process of being updated. Major goals are to improve the guidelines’ applicability and to take steps towards a living guideline according to current methodological standards. The aim of this article is to describe the main measures to achieve these goals. Methods: The context of the guideline in the field of local wound care and the stakeholder requirements are briefly described. Based on a derived framework, the project team adjusted the methods for the guideline. Results: Main adjustments are more specific inclusion criteria, online consensus meetings and the use of an authoring and publication platform to provide information in a multi-layered format. A new set of practice-oriented key questions were defined by the guideline panel to foster the formulation of action-oriented recommendations. Conclusions: The set of new key questions addressing practical problems and patients’ preferences as well as the adjustments made to improve not only the guidelines’ applicability, but also the feasibility of the further dynamic updating processes in the sense of a living guideline, should be steps in the right direction.

Limited Treatment Options for Diabetic Wounds: Barriers to Clinical Translation Despite Therapeutic Success in Murine Models

Significance: Millions of people worldwide suffer from diabetes mellitus and its complications, including chronic diabetic wounds. To date, there are few widely successful clinical therapies specific to diabetic wounds beyond general wound care, despite the vast number of scientific discoveries in the pathogenesis of defective healing in diabetes. Recent Advances: In recent years, murine animal models of diabetes have enabled the investigation of many possible therapeutics for diabetic wound care. These include specific cell types, growth factors, cytokines, peptides, small molecules, plant extracts, microRNAs, extracellular vesicles, novel wound dressings, mechanical interventions, bioengineered materials, and more. Critical Issues: Despite many research discoveries, few have been translated from their success in murine models to clinical use in humans. This massive gap between bench discovery and bedside application begs the simple and critical question: what is still missing? The complexity and multiplicity of the diabetic wound makes it an immensely challenging therapeutic target, and this lopsided progress highlights the need for new methods to overcome the bench-to-bedside barrier. How can laboratory discoveries in animal models be effectively translated to novel clinical therapies for human patients? Future Directions: As research continues to decipher deficient healing in diabetes, new approaches and considerations are required to ensure that these discoveries can become translational, clinically usable therapies. Clinical progress requires the development of new, more accurate models of the human disease state, multifaceted investigations that address multiple critical components in wound repair, and more innovative research strategies that harness both the existing knowledge and the potential of new advances across disciplines.

Antimicrobial Peptide Dendrimers and Quorum-Sensing Inhibitors in Formulating Next-Generation Anti-Infection Cell Therapy Dressings for Burns

Multidrug resistance infections are the main cause of failure in the pro-regenerative cell-mediated therapy of burn wounds. The collagen-based matrices for delivery of cells could be potential substrates to support bacterial growth and subsequent lysis of the collagen leading to a cell therapy loss. In this article, we report the development of a new generation of cell therapy formulations with the capacity to resist infections through the bactericidal effect of antimicrobial peptide dendrimers and the anti-virulence effect of anti-quorum sensing MvfR (PqsR) system compounds, which are incorporated into their formulation. Anti-quorum sensing compounds limit the pathogenicity and antibiotic tolerance of pathogenic bacteria involved in the burn wound infections, by inhibiting their virulence pathways. For the first time, we report a biological cell therapy dressing incorporating live progenitor cells, antimicrobial peptide dendrimers, and anti-MvfR compounds, which exhibit bactericidal and anti-virulence properties without compromising the viability of the progenitor cells.

Efficacy of Topical Vancomycin- and Gentamicin-Loaded Calcium Sulfate Beads or Systemic Antibiotics in Eradicating Polymicrobial Biofilms Isolated from Diabetic Foot Infections within an In Vitro Wound Model

Diabetic foot ulcers are notoriously difficult to heal, with ulcers often becoming chronic, in many cases leading to amputation despite weeks or months of antibiotic therapy in addition to debridement and offloading. Alternative wound biofilm management options, such as topical rather than systemic delivery of antimicrobials, have been investigated by clinicians in order to improve treatment outcomes. Here, we collected blood and tissue from six subjects with diabetic foot infections, measured the concentrations of antibiotics in the samples after treatment, and compared the microbiota within the tissue before treatment and after 7 days of antibiotic therapy. We used an in vitro model of polymicrobial biofilm infection inoculated with isolates from the tissue we collected to simulate different methods of antibiotic administration by simulated systemic therapy or topical release from calcium sulfate beads. We saw no difference in biofilm bioburden in the models after simulated systemic therapy (representative of antibiotics used in the clinic), but we did see reductions in bioburden of between 5 and 8 logs in five of the six biofilms that we tested with topical release of antibiotics via calcium sulfate beads. Yeast is insensitive to antibiotics and was a component of the sixth biofilm. These data support further studies of the topical release of antibiotics from calcium sulfate beads in diabetic foot infections to combat the aggregate issues of infectious organisms taking the biofilm mode of growth, compromised immune involvement, and poor systemic delivery of antibiotics via the bloodstream to the site of infection in patients with diabetes.

Plant Leaves Extract Irrigation on Wound Healing in Diabetic Foot Ulcers

Purpose

We aimed to evaluate and compare the efficacy of neem leaves extract with normal saline irrigation practice in wound dressing on healing outcome and clinic-physiological parameters among individuals with diabetic foot ulcer (DFU).

Methods

A quasiexperimental with repeated measures design was used on two study groups. One group received neem leaf extract wound irrigation and another group received normal saline wound irrigation. Study participants were randomly assigned to each group from 100 DFU individuals. Demographic and clinical data sheets were used to collect baseline information. Random blood sugar and HbA1C measurement was performed on the initial day of visit for all participants. We used the PUSH tool for wound assessment (wound surface area, exudate amount, and tissue type), and clinic physiological parameters (temperature, pulse rate, respiration, blood pressure, wound pain, wound infection, and local warmth) assessment was performed at baseline and then at the end of each week till four weeks were completed. Participants attended a foot clinic every 3rd or 4th day for wound care.

Results

Reduction of wound healing score (PUSH score) and other wound variables improved significantly in the neem leaves extract group (p < 0.001). There were no significant changes in the clinic-physiological parameters.

Conclusion

Neem leaves extract irrigation for foot ulcers is considered to be very safe as it did not cause any complication systematically during the study. Neem leaf extract solution can be used as an alternative solution for normal saline. Managing DFU requires continuous foot care and early risk identification of ulcer.

Antimicrobial stewardship of antiseptics that are pertinent to wounds: the need for a united approach

Long before the nature of infection was recognized, or the significance of biofilms in delayed healing was understood, antimicrobial agents were being used in wound care. In the last 70 years, antibiotics have provided an effective means to control wound infection, but the continued emergence of antibiotic-resistant strains and the documented antibiotic tolerance of biofilms has reduced their effectiveness. A range of wound dressings containing an antimicrobial (antibiotic or non-antibiotic compound) has been developed. Whereas standardized methods for determining the efficacy of non-antibiotic antimicrobials in bacterial suspension tests were developed in the early twentieth century, standardized ways of evaluating the efficacy of antimicrobial dressings against microbial suspensions and biofilms are not available. Resistance to non-antibiotic antimicrobials and cross-resistance with antibiotics has been reported, but consensus on breakpoints is absent and surveillance is impossible. Antimicrobial stewardship is therefore in jeopardy. This review highlights these difficulties and in particular the efficacy of current non-antibiotic antimicrobials used in dressings, their efficacy, and the challenges of translating in vitro efficacy data to the efficacy of dressings in patients. This review calls for a unified approach to developing standardized methods of evaluating antimicrobial dressings that will provide an improved basis for practitioners to make informed choices in wound care.

The Role of Oxidative Stress and Antioxidants in Diabetic Wound Healing

Foot ulcers are one of the most common and severe complication of diabetes mellitus with significant resultant morbidity and mortality. Multiple factors impair wound healing include skin injury, diabetic neuropathy, ischemia, infection, inadequate glycemic control, poor nutritional status, and severe morbidity. It is currently believed that oxidative stress plays a vital role in diabetic wound healing. An imbalance of free radicals and antioxidants in the body results in overproduction of reactive oxygen species which lead to cell, tissue damage, and delayed wound healing. Therefore, decreasing ROS levels through antioxidative systems may reduce oxidative stress-induced damage to improve healing. In this context, we provide an update on the role of oxidative stress and antioxidants in diabetic wound healing through following four perspectives. We then discuss several therapeutic strategies especially dietary bioactive compounds by targeting oxidative stress to improve wounds healing.

Polyphenols: A Promising Avenue in Therapeutic Solutions for Wound Care

In chronic wounds, the regeneration process is compromised, which brings complexity to the therapeutic approaches that need to be adopted, while representing an enormous loss in the patients’ quality of life with consequent economical costs. Chronic wounds are highly prone to infection, which can ultimately lead to septicemia and morbidity. Classic therapies are increasing antibiotic resistance, which is becoming a critical problem beyond complex wounds. Therefore, it is essential to study new antimicrobial polymeric systems and compounds that can be effective alternatives to reduce infection, even at lower concentrations. The biological potential of polyphenols allows them to be an efficient alternative to commercial antibiotics, responding to the need to find new options for chronic wound care. Nonetheless, phenolic compounds may have some drawbacks when targeting wound applications, such as low stability and consequent decreased biological performance at the wound site. To overcome these limitations, polymeric-based systems have been developed as carriers of polyphenols for wound healing, improving its stability, controlling the release kinetics, and therefore increasing the performance and effectiveness. This review aims to highlight possible smart and bio-based wound dressings, providing an overview of the biological potential of polyphenolic agents as natural antimicrobial agents and strategies to stabilize and deliver them in the treatment of complex wounds. Polymer-based particulate systems are highlighted here due to their impact as carriers to increase polyphenols bioavailability at the wound site in different types of formulations.

Silver Sulfadiazine Eradicates Antibiotic-Tolerant Staphylococcus aureus and Pseudomonas aeruginosa Biofilms in Patients with Infected Diabetic Foot Ulcers

Infections are among the most frequent and challenging events in diabetic foot ulcers (DFUs). Pathogenic bacteria growing in biofilms within host tissue are highly tolerant to environmental and chemical agents, including antibiotics. The present study was aimed at assessing the use of silver sulfadiazine (SSD) for wound healing and infection control in 16 patients with DFUs harboring biofilm-growing Staphylococcus aureus and Pseudomonas aeruginosa. All patients received a treatment based on a dressing protocol including disinfection, cleansing, application of SSD, and application of nonadherent gauze, followed by sterile gauze and tibio-breech bandage, in preparation for toilet surgery after 30 days of treatment. Clinical parameters were analyzed by the T.I.M.E. classification system. In addition, the activity of SSD against biofilm-growing S. aureus and P. aeruginosa isolates was assessed in vitro. A total of 16 patients with S. aureus and P. aeruginosa infected DFUs were included in the study. Clinical data showed a statistically significant (p < 0.002) improvement of patients' DFUs after 30 days of treatment with SSD with significant amelioration of all the parameters analyzed. Notably, after 30 days of treatment, resolution of infection was observed in all DFUs. In vitro analysis showed that both S. aureus and P. aeruginosa isolates developed complex and highly structured biofilms. Antibiotic susceptibility profiles indicated that biofilm cultures were significantly (p ≤ 0.002) more tolerant to all tested antimicrobials than their planktonic counterparts. However, SSD was found to be effective against fully developed biofilms of both S. aureus and P. aeruginosa at concentrations below those normally used in clinical preparations (10 mg/mL). These results strongly suggest that the topical administration of SSD may represent an effective alternative to conventional antibiotics for the successful treatment of DFUs infected by biofilm-growing S. aureus and P. aeruginosa.

Antibacterial-Integrated Collagen Wound Dressing for Diabetes-Related Foot Ulcers: An Evidence-Based Review of Clinical Studies

Diabetic foot ulcer (DFU) is a chronic wound frequently delayed from severe infection. Wound dressing provides an essential barrier between the ulcer and the external environment. This review aimed to analyse the effectiveness of antibacterial collagen-based dressing for DFU treatment in a clinical setting. An electronic search in four databases, namely, Scopus, PubMed, Ovid MEDLINE(R), and ISI Web of Science, was performed to obtain relevant articles published within the last ten years. The published studies were included if they reported evidence of (1) collagen-based antibacterial dressing or (2) wound healing for diabetic ulcers, and (3) were written in English. Both randomised and non-randomised clinical trials were included. The search for relevant clinical studies (n) identified eight related references discussing the effectiveness of collagen-based antibacterial wound dressings for DFU comprising collagen impregnated with polyhexamethylene biguanide (n = 2), gentamicin (n = 3), combined-cellulose and silver (n = 1), gentian violet/methylene blue mixed (n = 1), and silver (n = 1). The clinical data were limited by small sample sizes and multiple aetiologies of chronic wounds. The evidence was not robust enough for a conclusive statement, although most of the studies reported positive outcomes for the use of collagen dressings loaded with antibacterial properties for DFU wound healing. This study emphasises the importance of having standardised clinical trials, larger sample sizes, and accurate reporting for reliable statistical evidence confirming DFU treatment efficiency.

Crustacean Proteases and Their Application in Debridement

Digestive proteases from marine organisms have been poorly applied to biomedicine. Exceptions are trypsin and other digestive proteases from a few cold-adapted or temperate fish and crustacean species. These enzymes are more efficient than enzymes from microorganism and higher vertebrates that have been used traditionally. However, the biomedical potential of digestive proteases from warm environment species has received less research attention. This review aims to provide an overview of this unrealised biomedical potential, using the debridement application as a paradigm. Debridement is intended to remove nonviable, necrotic and contaminated tissue, as well as fibrin clots, and is a key step in wound treatment. We discuss the physiological role of enzymes in wound healing, the use of exogenous enzymes in debridement, and the limitations of cold-adapted enzymes such as their poor thermal stability. We show that digestive proteases from tropical crustaceans may have advantages over their cold-adapted counterparts for this and similar uses. Differences in thermal stability, auto-proteolytic stability, and susceptibility to proteinase inhibitors are discussed. Furthermore, it is proposed that the feeding behaviour of the source organism may direct the evaluation of enzymes for particular applications, as digestive proteases have evolved to fill a wide variety of feeding habitats, natural substrates, and environmental conditions. We encourage more research on the biomedical application of digestive enzymes from tropical marine crustaceans.

Are Antimicrobial Peptide Dendrimers an Escape from ESKAPE?

Significance: The crisis of antimicrobial resistance (AMR) increases dramatically despite all efforts to use available antibiotics or last resort antimicrobial agents. The spread of the AMR, declared as one of the most important health-related issues, warrants the development of new antimicrobial strategies. Recent Advances: Antimicrobial peptides (AMPs) and AMP dendrimers (AMPDs), as well as polymer dendrimers are relatively new and promising strategies with the potential to overcome drug resistance issues arising in ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) colonizing chronic wounds. Critical Issues: AMPs-AMPDs suffer from limited efficacy, short-lasting bioactivity, and concerns of toxicity. To circumvent these drawbacks, their covalent coupling to biopolymers and/or encapsulation into different drug carrier systems is investigated, with a special focus on topical applications. Future Directions: Scientists and the pharmaceutical industry should focus on this challenging subject to either improve the activity of existing antimicrobial agents or find new drug candidates. The focus should be put on the discovery of new drugs or the combination of existing drugs for a better synergy, taking into account all kinds of wounds and existing pathogens, and more specifically on the development of next-generation antimicrobial peptides, encompassing the delivery carrier toward improved pharmacokinetics and efficacy.

In Vitro Efficiency of Antimicrobial Peptides against Staphylococcal Pathogens Associated with Canine Pyoderma

Simple Summary

Coagulase-positive staphylococci (CoPS) are predominant pathogens in canine pyoderma, especially S. pseudintermedius and S. aureus. The antimicrobial resistance of CoPS has a key role in the management of canine skin infections. The vast majority of those diseases have a chronic character with a tendency to recur, which is reflected by recurrent systemic antibiotic therapy, associated with an alarming increase in the proportion of antibiotic-resistant staphylococci. Antimicrobial peptides (AMPs) seem to be a promising alternative to conventional antibiotics. The aim of this in vitro study was to evaluate the antimicrobial activity of selected AMPs against pathogenic staphylococcal strains, including multidrug- and methicillin-resistant strains isolated from canine pyoderma cases. The tested AMPs were shown to be equally efficient antimicrobial agents against resistant- and susceptible pathogenic staphylococcal strains associated with canine pyoderma. AMPs were more efficient against S. pseudintermedius than against S. aureus strains. Our findings seem to be particularly interesting from a clinical perspective, as a starting point from which to perform in vivo experiments to estimate the usefulness of these peptides as topical drug molecules for the treatment of canine pyoderma.

Abstract

The emergence of staphylococcal canine pathogens resistant to multiple antimicrobial agents is a growing and urgent problem in veterinary practice. Antimicrobial peptides (AMPs) seem to be a promising alternative to conventional antibiotics. The aim of this in vitro study was to evaluate the antimicrobial activity of selected AMPs against pathogenic staphylococcal strains, including multidrug- and methicillin-resistant strains isolated from canine pyoderma cases. Seven antimicrobial peptides (aurein 1.2, CAMEL, citropin 1.1, protegrin-1, pexiganan, temporin A and uperin 3.6) synthesized by the 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase method were tested. The minimal inhibitory and minimal bactericidal concentrations (MIC and MBC) were determined by the broth microdilution method. The study showed that analyzed AMPs exerted an extensive effect against canine pathogens, with the most active peptide being uperin 3.6. The tested AMPs were equally efficient against both resistant- and susceptible staphylococcal strains and were more efficient against Staphylococcus pseudintermedius than against Staphylococcus aureus strains. Our findings are particularly interesting from a clinical perspective, as they point to AMPs as potential therapeutic topical agents in canine pyoderma cases associated with antimicrobial resistance of staphylococci.

Susceptibility of monomicrobial or polymicrobial biofilms derived from infected diabetic foot ulcers to topical or systemic antibiotics in vitro

Diabetic foot ulcers can become chronic and non-healing despite systemic antibiotic treatment. The penetration of systematically-administered antibiotics to the site of infection is uncertain, as is the effectiveness of such levels against polymicrobial biofilms. We have developed an in vitro model to study the effectiveness of different treatments for infected diabetic foot ulcers in a wound-like environment and compared the activity of systemic levels of antibiotics with that for topically applied antibiotics released from calcium sulfate beads. This is the first study that has harvested bacteria from diabetic foot infections and recreated similar polymicrobial biofilms to those present in vivo for individual subjects. After treatment with levels of gentamicin attained in serum after systemic administration (higher than corresponding tissues concentrations) we measured a 0-2 log reduction in bacterial viability of P. aeruginosa, S. aureus or a polymicrobial biofilm. Conversely, addition of gentamicin loaded calcium sulfate beads resulted in 5-9 log reductions in P. aeruginosa, S aureus and polymicrobial biofilms derived from three subjects. We conclude that systemically administered antibiotics are likely to be inadequate for successfully treating these infections, especially given the vastly increased concentrations required to inhibit cells in a biofilm, and that topical antibiotics provide a more effective alternative.

New Antibacterial Paper Made of Silver Phosphate Cellulose Fibers: A Preliminary Study on the Elimination of Staphylococcus aureus Involved in Diabetic Foot Ulceration

AIM

To evaluate in vitro the antibacterial effect of a paper made of silver phosphate cellulose fibers (SPCF) on Staphylococcus aureus, the most common diabetic foot ulceration (DFU) pathogen when compared with other common commercial products.

METHODS

The antibacterial activity of SPCF samples was evaluated through time with cell counting on agar plates. SPCF samples were then compared with commercial wound care products currently in use in DFU treatments (Silvercel™, Acticoat 7, and Aquacel Ag ExtraTM) through time on agar plates (growth inhibition zones).

RESULTS

After 6 hours, there was no viable bacterial cell detected on either plate (p < 0.05). There was a net growth inhibition zone for SPCF samples but no significant difference between the two silver concentrations. Compared with common commercial products, SPCF paper provides results equal to Acticoat 7 (p < 0.05). There was a net growth inhibition zone for SPCF samples but no significant difference between the two silver concentrations. Compared with common commercial products, SPCF paper provides results equal to Acticoat 7 (p < 0.05). There was a net growth inhibition zone for SPCF samples but no significant difference between the two silver concentrations. Compared with common commercial products, SPCF paper provides results equal to Acticoat 7 (.

CONCLUSIONS

These results have shown the efficiency of SPCF paper to eliminate Staphylococcus aureus in these conditions. SPCF papers are effective when compared with other common commercial products and could have an industrial potential in wound care. Infected DFU could benefit from the antibacterial effectiveness of SPCF, but more relevant experimentations related to foot ulcers are needed.Staphylococcus aureus, the most common diabetic foot ulceration (DFU) pathogen when compared with other common commercial products.

A comparative study on the cellular viability and debridement efficiency of antimicrobial-based wound dressings

A concentrated surfactant gel containing polyhexamethylene biguanide (CSG-PHMB) (CSG: Plurogel) was evaluated for in vitro cell cytotoxicity using the direct contact, extraction, and cell insert assays, along with its ability to breakdown artificial wound eschar and slough, compared with other clinically available wound gels: a wound gel loaded with 0.13% benzalkonium chloride (BXG) and a highly viscous gel loaded with 0.1% polyhexamethylene biguanide (PXG). Following treatment with CSG-PHMB, BXG, and PXG at day 1, the viability of L929 and HDFa cells sharply decreased to lower than 20% of the culture media control in the direct contact assay; however, cell viability of L929 was 128.65 ± 1.41%, 99.90 ± 2.84%*, and 64.08 ± 5.99%* respectively; HDFa was 84.58 ± 10.41%, 19.54 ± 3.06%**, and 96.28 ± 33.67%, respectively, in the extraction assay. In the cell insert model, cell viability of L929 cells were 95.25 ± 0.96%, 47.49 ± 5.37%**, and 48.63 ± 7.00%**, respectively; HDFa cell viability were 92.80 ± 1.29%, 38.86 ± 4.28%**, and 49.90 ± 2.55%** (*: P < .01; **P < .001 compared with CSG-PHMB; cell viability of culture medium without treatment at day 1 was 100%). The cell extraction model on day 1 indicated that CSG-PHMB had higher viability of L929 cells compared with BXG. In addition, the cellular viability results indicated that CSG-PHMB gel exhibited lower cytotoxicity when compared with BXG and PXG in the cell insert model assay. Within the in vitro debridement model, CSG-PHMB exhibited an ability to potentially increase the loosening of the collagen matrix. The reason for this may be because of the concentrated surfactant found within the CSG-PHMB, which has the ability to lower the surface tension, aiding in the movements of fragments and debris in the fluorescent artificial wound eschar model (fAWE).

Effect on total microbial load and community composition with two vs six-week topical Cadexomer Iodine for treating chronic biofilm infections in diabetic foot ulcers

This study compares two vs six weeks of topical antimicrobial therapy with Cadexomer Iodine in patients with diabetic foot ulcers (DFUs) complicated by chronic biofilm infections. Patients with non-healing DFUs with suspected chronic biofilm infections were eligible for enrolment. Patients were randomised to receive either two or six weeks of treatment with topical Cadexomer Iodine. Tissue biopsies from the ulcers were obtained pre-and-post treatment and underwent DNA sequencing and real-time quantitative polymerase chain reaction (PCR) to determine the total microbial load, community composition, and diversity of bacteria. Scanning electron microscopy confirmed biofilm in all 18 ulcers with suspected chronic biofilm infections. Cadexomer Iodine resulted in 14 of 18 (78%) samples achieving a mean 0.5 log10 reduction in microbial load. Regardless of treatment duration, there was no statistical difference in the reduction of total microbial loads. No difference in the rate of wound healing in the two groups was seen at 6 weeks. Cadexomer Iodine reduces the total microbial load in DFUs with chronic biofilm infections and affects microbial community composition and diversity. All ulcers in both groups showed an initial reduction in wound size with application of Cadexomer Iodine, which might reflect its effect on biofilms.

Noninvasive staging of pressure ulcers using photoacoustic imaging

Ulcers including pressure ulcers and diabetic foot ulcers damage the skin and underlying tissue in people with compromised blood circulation. They are classified into four stages of severity and span from mild reddening of the skin to tissue damage and muscle/bone infections. Here, we used photoacoustic imaging as a noninvasive method for detecting early tissue damage that cannot be visually observed while also staging the disease using quantitative image analysis. We used a mouse model of pressure ulcers by implanting subdermal magnets in the dorsal flank and periodically applying an external magnet to the healed implant site. The magnet-induced pressure was applied in cycles, and the extent of ulceration was dictated by the number of cycles. We used both laser- and light-emitting diode (LED)-based photoacoustic imaging tools with 690 nm excitation to evaluate the change in photoacoustic signal and depth of injury. Using laser-based photoacoustic imaging system, we found a 4.4-fold increase in the photoacoustic intensity in stage I vs. baseline (no pressure). We also evaluated the depth of injury using photoacoustics. We measured a photoacoustic ulcer depth of 0.38 ± 0.09 mm, 0.74 ± 0.11 mm, 1.63 ± 0.4 mm, and 2.7 ± 0.31 mm (n = 4) for stages I-IV, respectively. The photoacoustic depth differences between each stage were significant (p < 0.05). We also used an LED-based photoacoustic imaging system to detect early stage (stage I) pressure ulcers and observed a 2.5-fold increase in photoacoustic signal. Importantly, we confirmed the capacity of this technique to detect dysregulated skin even before stage I ulcers have erupted. We also observed significant changes in photoacoustic intensity during healing suggesting that this approach can monitor therapy. These findings were confirmed with histology. These results suggest that this photoacoustic-based approach might have clinical value for monitoring skin diseases including pressure ulcers.