The Cutaneous Microbiome and Wounds: New Molecular Targets to Promote Wound Healing

Insights on Gut and Skin Wound Microbiome in Stranded Indo-Pacific Finless Porpoise (Neophocaena phocaenoides)

The gut microbiome is a unique marker for cetaceans’ health status, and the microbiome composition of their skin wounds can indicate a potential infection from their habitat. Our study provides the first comparative analysis of the microbial communities from gut regions and skin wounds of an individual Indo-Pacific finless porpoise (Neophocaena phocaenoides). Microbial richness increased from the foregut to the hindgut with variation in the composition of microbes. Fusobacteria (67.51% ± 5.10%), Firmicutes (22.00% ± 2.60%), and Proteobacteria (10.47% ± 5.49%) were the dominant phyla in the gastrointestinal tract, while Proteobacteria (76.11% ± 0.54%), Firmicutes (22.00% ± 2.60%), and Bacteroidetes (10.13% ± 0.49%) were the dominant phyla in the skin wounds. The genera Photobacterium, Actinobacillus, Vibrio, Erysipelothrix, Tenacibaculum, and Psychrobacter, considered potential pathogens for mammals, were identified in the gut and skin wounds of the stranded Indo-Pacific finless porpoise. A comparison of the gut microbiome in the Indo-Pacific finless porpoise and other cetaceans revealed a possible species-specific gut microbiome in the Indo-Pacific finless porpoise. There was a significant difference between the skin wound microbiomes in terrestrial and marine mammals, probably due to habitat-specific differences. Our results show potential species specificity in the microbiome structure and a potential threat posed by environmental pathogens to cetaceans.

Antimicrobial Combined Action of Graphene Oxide and Light Emitting Diodes for Chronic Wound Management

Innovative non-antibiotic compounds such as graphene oxide (GO) and light-emitting diodes (LEDs) may represent a valid strategy for managing chronic wound infections related to resistant pathogens. This study aimed to evaluate 630 nm LED and 880 nm LED ability to enhance the GO antimicrobial activity against Staphylococcus aureus- and Pseudomonas aeruginosa-resistant strains in a dual-species biofilm in the Lubbock chronic wound biofilm (LCWB) model. The effect of a 630 nm LED, alone or plus 5-aminolevulinic acid (ALAD)-mediated photodynamic therapy (PDT) (ALAD-PDT), or an 880 nm LED on the GO (50 mg/l) action was evaluated by determining the CFU/mg reductions, live/dead analysis, scanning electron microscope observation, and reactive oxygen species assay. Among the LCWBs, the best effect was obtained with GO irradiated with ALAD-PDT, with percentages of CFU/mg reduction up to 78.96% ± 0.21 and 95.17% ± 2.56 for S. aureus and P. aeruginosa, respectively. The microscope images showed a reduction in the cell number and viability when treated with GO + ALAD-PDT. In addition, increased ROS production was detected. No differences were recorded when GO was irradiated with an 880 nm LED versus GO alone. The obtained results suggest that treatment with GO irradiated with ALAD-PDT represents a valid, sustainable strategy to counteract the polymicrobial colonization of chronic wounds.

Challenges and innovations in treating chronic and acute wound infections: from basic science to clinical practice

Acute and chronic wound infection has become a major worldwide healthcare burden leading to significantly high morbidity and mortality. The underlying mechanism of infections has been widely investigated by scientist, while standard wound management is routinely been used in general practice. However, strategies for the diagnosis and treatment of wound infections remain a great challenge due to the occurrence of biofilm colonization, delayed healing and drug resistance. In the present review, we summarize the common microorganisms found in acute and chronic wound infections and discuss the challenges from the aspects of clinical diagnosis, non-surgical methods and surgical methods. Moreover, we highlight emerging innovations in the development of antimicrobial peptides, phages, controlled drug delivery, wound dressing materials and herbal medicine, and find that sensitive diagnostics, combined treatment and skin microbiome regulation could be future directions in the treatment of wound infection.

The Prospects of Swietenia macrophylla King in Skin Care

The importance of cosmetics in our lives is immeasurable. Covering items from daily personal hygienic products to skincare, it has become essential to consumers that the items that they use are safe and effective. Since natural products are from natural sources, and therefore considered “natural” and “green” in the public’s eyes, the rise in demand for such products is not surprising. Even so, factoring in the need to remain on trend and innovative, cosmetic companies are on a constant search for new ingredients and inventive new formulations. Based on numerous literature, the seed of Swietenia macrophylla has been shown to possess several potential “cosmetic-worthy” bioproperties, such as skin whitening, photoprotective, antioxidant, antimicrobial, etc. These properties are vital in the cosmetic business, as they ultimately contribute to the “ageless” beauty that many consumers yearn for. Therefore, with further refinement and research, these active phytocompounds may be a great contribution to the cosmetic field in the near future.

Laryngotracheal stenosis: Mechanistic review

Background

The purpose of this review article is to summarize the existing literature surrounding wound healing mechanisms in laryngotracheal stenosis.

Methods

A review of general wound healing pathophysiology, followed by a focused review of iatrogenic laryngotracheal stenosis (iLTS) and idiopathic subglottic stenosis (iSGS) as conditions of aberrant wound healing.

Results

iLTS is the scarring of the laryngotracheal complex, coming secondary to injury from prolonged intubation. iSGS is a chronic fibroinflammatory scarring and narrowing of the subglottic airway in the absence of any obvious preceding injury or trauma. They are both thought to result from a prolonged and dysregulated wound healing response that promotes the deposition of pathologic scar in the airway.

Conclusions

Understanding the mechanisms that underlie wound healing will help identify and intervene on the process early in its development and discover future therapies that target individual wound healing mechanisms limiting the incidence of this recalcitrant disease process.

The Chronic Wound Phageome: Phage Diversity and Associations with Wounds and Healing Outcomes

Two leading impediments to chronic wound healing are polymicrobial infection and biofilm formation. Recent studies have characterized the bacterial fraction of these microbiomes and have begun to elucidate compositional correlations to healing outcomes. However, the factors that drive compositional shifts are still being uncovered. The virome may play an important role in shaping bacterial community structure and function. Previous work on the skin virome determined that it was dominated by bacteriophages, viruses that infect bacteria. To characterize the virome, we enrolled 20 chronic wound patients presenting at an outpatient wound care clinic in a microbiome survey, collecting swab samples from healthy skin and chronic wounds (diabetic, venous, arterial, or pressure) before and after a single, sharp debridement procedure. We investigated the virome using a virus-like particle enrichment procedure, shotgun metagenomic sequencing, and a k-mer-based, reference-dependent taxonomic classification method. Taxonomic composition, diversity, and associations with covariates are presented. We find that the wound virome is highly diverse, with many phages targeting known pathogens, and may influence bacterial community composition and functionality in ways that impact healing outcomes.

IMPORTANCE Chronic wounds are an increasing medical burden. These wounds are known to be rich in microbial content, including both bacteria and bacterial viruses (phages). The viruses may play an important role in shaping bacterial community structure and function. We analyzed the virome and bacterial composition of 20 patients with chronic wounds. The viruses found in wounds are highly diverse compared to normal skin, unlike the bacterial composition, where diversity is decreased. These data represent an initial look at this relatively understudied component of the chronic wound microbiome and may help inform future phage-based interventions.

The 3-D configuration of excisional skin wound healing after topical probiotic application

Nowadays, there is an increasing knowledge that probiotic bacteria, topically applied, affects skin pathology. The objective of this study is to evaluate the effect on wound healing of locally applied probiotics by calculating the 3-D configuration of a standardized excisional wound. Fifty-two male Wistar rats were randomly allocated into groups: control, PRO1 [L. plantarum] and PRO2 [L. rhamnosus, B. longum]. Six excisional full-thickness wounds were created on each dorsum by an 8-mm circular biopsy punch; probiotics or saline were applied on days 0, 2, 4, 8, 16, photos of the wounds taken and specimens excised for histology [4 rats/group/time-point]. Both probiotic-groups exhibited accelerated healing significantly faster than the control, throughout, PRO2 exhibiting finally the best results [day 16]. However, only on day 2, did PRO1 exhibit the best results [wounded area, borders distance and epitheliazation line]. The results clearly demonstrate that the topical application of probiotics significantly improves the healing process, each strain working differently and more effectively in different healing phases. Thus, a combined formula containing different probiotics to modulate various healing phases is desirable. To this end our research continous.

Multiwalled carbon nanotubes functionalized bacterial cellulose as an efficient healing material for diabetic wounds

The unique pool of features makes bacterial cellulose (BC) a robust platform to tailor its functionalities. Herein, the BC matrix was reinforced with multiwalled carbon nanotubes (MWCNT) to control infection and accelerate the healing process of diabetic wounds. The prepared BC-MWCNT composite film was characterized and antibacterial activity was assessed. Further, the in-vivo wound healing activity was performed and temporal expression of interleukin (IL-1α), tumor necrosis factor (TNF-α), vascular endothelial growth factor (VEGF) and platelets derived growth factor (PDGF) was quantitatively measured by real-time PCR. The characterization results confirmed the reinforcement of the BC matrix with MWCNT. The composite film showed antibacterial activity against all the tested strains. Moreover, the macroscopic analysis of the wound demonstrated faster closure of the diabetic wound in BC-MWCNT group (99% healing) as compared to negative control (77%) in 21 days. Histological studies further supported the results where complete reepithelization of the epidermis and healthy granulation tissue were observed in BC-MWCNT treated group. Molecular studies revealed that BC-MWCNT group showed relatively lesser expression of pro-inflammatory cytokines IL-1α and TNF-α and higher expression of VEGF than control that may have favored the faster healing. This study suggested that the tailorable properties of BC can be exploited to develop composites with potential applications in diabetic wound healing.

Interspecies Regulation Between Staphylococcus caprae and Staphylococcus aureus Colonized on Healed Skin After Injury

Staphylococcus spp. colonize commensally on the human skin. Some commensal coagulase-negative staphylococci and Staphylococcus aureus are also involved in nosocomial infections. Bacteria were collected from skin healed from pressure injury (PI). After the collection time points, some patients suffered from recurrent PI (RPI). This study analyzed the characteristics of Staphylococcus spp. on healed skin before recurrence between healed skin that suffered from RPI within 6 weeks (RPI group) and healed skin that did not suffer within the duration (non-RPI group) by Staphylococcus spp.-specific sequencing. Of the seven patients in the RPI group, two were dominated by S. aureus and four by Staphylococcus caprae, coagulase-negative human commensal staphylococci in the RPI group. Using mouse models, both S. caprae and S. aureus, but not Staphylococcus epidermidis, colonized on skin healed from injury at significantly higher rates than normal skin. Although subcutaneous injection of S. caprae did not induce lesion formation, the bacterium exhibited high hemolytic activity on human red blood cells. Lesion formation by subcutaneous injection of S. aureus was significantly suppressed in the presence of S. caprae. The hemolytic activity of rabbit blood cells of S. aureus was suppressed by S. caprae, whereas the hemolytic activity of S. caprae was dramatically suppressed by S. aureus. Data indicated that each of the two Staphylococcus spp. suppresses the pathogenicity of the other and that the imbalance between the two is associated with RPI.

Fabrication of chitosan/PVP/dihydroquercetin nanocomposite film for in vitro and in vivo evaluation of wound healing

The high cost of wound healing treatment, the slow recovery of wounds, and the uncertainty of being affected by the body's physiological activities constitute a serious burden on public health. In this work, we report the preparation and characterization of chitosan (CS), PVP, and dihydroquercetin (DHQ) nanofiber film used as wound excipients, as well as in vivo and in vitro evaluations, and verify that the film is effective in wounds. The results show that the prepared film has good morphology, thermal stability and hydrophilicity. In vitro studies have shown that it has antibacterial activity against S.aureus and E.coli, and the DPPH free radical scavenging rate proves that the fiber film has antioxidant activity. MTT cytotoxicity test proved that the film is non-toxic to Hacat cells. Animal experiments have proved that wounds treated with CS-PVP-DHQ nanofiber film heal faster. This article also studied the composite nanofiber film by inducing autophagy pathway and increasing the expression of pan-keratin, vascular endothelial growth factor VEGF and CD31 to promote wound healing. Therefore, the nanofiber film herein show great potential in wound healing applications.

The Gut-Skin Microbiota Axis and Its Role in Diabetic Wound Healing-A Review Based on Current Literature

Diabetic foot ulcers (DFU) are a growing concern worldwide as they pose complications in routine clinical practices such as diagnosis and management. Bacterial interactions on the skin surface are vital to the pathophysiology of DFU and may control delayed wound healing. The microbiota from our skin directly regulates cutaneous health and disease by interacting with the numerous cells involved in the wound healing mechanism. Commensal microbiota, in particular, interact with wound-repairing skin cells to enhance barrier regeneration. The observed microbes in DFU include Staphylococcus, Streptococcus, Corynebacterium, Pseudomonas, and several anaerobes. Skin commensal microbes, namely S. epidermidis, can regulate the gamma delta T cells and induce Perforin-2 expression. The increased expression of Perforin-2 by skin cells destroyed S. aureus within the cells, facilitating wound healing. Possible crosstalk between the human commensal microbiome and different cell types involved in cutaneous wound healing promotes the immune response and helps to maintain the barrier function in humans. Wound healing is a highly well-coordinated, complex mechanism; it can be devastating if interrupted. Skin microbiomes are being studied in relation to the gut-skin axis along with their effects on dermatologic conditions. The gut-skin axis illustrates the connection wherein the gut can impact skin health due to its immunological and metabolic properties. The precise mechanism underlying gut-skin microbial interactions is still unidentified, but the immune and endocrine systems are likely to be involved. Next-generation sequencing and the development of bioinformatics pipelines may considerably improve the understanding of the microbiome-skin axis involved in diabetic wound healing in a much more sophisticated way. We endeavor to shed light on the importance of these pathways in the pathomechanisms of the most prevalent inflammatory conditions including the diabetes wound healing, as well as how probiotics may intervene in the gut-skin axis.

Synthesis and Biological Evaluation of Novel Cinnamic Acid-Based Antimicrobials

The main antimicrobial resistance (AMR) nosocomial strains (ESKAPE pathogens such as Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are the most widespread bacteria in cutaneous infections. In this work we report the synthesis, in silico skin permeability prediction, antimicrobial, antibiofilm, and wound healing properties of novel cinnamic acid-based antimicrobials (DM1–11) as novel antibacterial drugs for the treatment of ESKAPE-related skin infections. Antimicrobial and wound healing scratch assays were performed to evaluate the antibacterial properties of DM1–11. In silico skin permeability capabilities of DM1–11 were evaluated using Swiss-ADME online database. Cytotoxicity assays were performed on keratinocytes and fibroblasts. DM2, bearing a catechol group on the aromatic ring of the cinnamic portion of the molecule, possesses a significant antibacterial activity against S. aureus (MIC range 16–64 mg/L) and contrasts the biofilm-mediated S. epidermidis infection at low concentrations. Wound healing assays showed that wound closure in 48 h was observed in DM2-treated keratinocytes with a better healing pattern at all the used concentrations (0.1, 1.0, and 10 µM). A potential good skin permeation for DM2, that could guarantee its effectiveness at the target site, was also observed. Cytotoxicity studies revealed that DM2 may be a safe compound for topical use. Taking together all these data confirm that DM2 could represent a safe wound-healing topical agent for the treatment of skin wound infections caused by two of main Gram-positive bacteria belonging to ESKAPE microorganisms.

High fat diet induced gut dysbiosis alters corneal epithelial injury response in mice

PURPOSE

Commensal microbiome secretes various metabolites that can exert important effects on the host immunity and inflammation and can alter cellular functions. However, little is known regarding the effect of microbiome on corneal immunity and genetic expression. The purpose of this study is to describe the effect of diet-induced gut dysbiosis on corneal immunity and corneal gene expression after wounding.

METHODS

This study is approved by the Animal Care and Use of the University of Illinois. Six-week-old female C57BL6 mice were fed on a normal chow diet (ND), isocaloric low-fat control diet (LFD), or a 21% milk high-fat diet (HFD) for six weeks. 2 mm corneal epithelial debridement was performed (n = 10). Fecal samples from mice were used for microbial diversity analysis (n > 3). Immunofluorescence staining of corneal wholemount tissue post-debridement was used to visualize immune cell distribution. RNA Seq was performed on tissue samples from corneas following debridement.

RESULTS

Mice fed differing diets had significant alterations in gut microbial diversities. After corneal debridement, HFD mice experienced delayed wound healing in comparison to LFD mice and ND mice groups. However, fecal transplantation led to normalization of wound closure rates. Increased γδTCR staining was observed in the LFD group, and decreased LY6G was observed in HFD group (p < 0.05). Gene Ontology terms of differentially expressed genes included response to external stimulus, cell proliferation, migration, adhesion, defense response and leukocyte migration. Top over-represented pathways included ECM-receptor interaction, Cytokine-cytokine receptor interaction, Focal adhesion and Leukocyte trans-endothelial migration.

CONCLUSIONS

Gut microbial dysbiosis alters corneal immune cell distribution, corneal response to injury, and genes related to epithelial function and corneal immunity.

The Wound-Healing Effect of Mango Peel Extract on Incision Wounds in a Murine Model

Mangifera indica can generate up to 60% of polluting by-products, including peels. However, it has been shown that flavonoids and mangiferin are mainly responsible for the antioxidant, anti-inflammatory, and antibacterial activities closely related to the wound-healing process. The chemical composition of MEMI (methanolic extract of M. indica) was analyzed by HPLC-DAD, as well as concentrations of total phenol (TPC) and flavonoids (TFC) and antioxidant activity (SA₅₀). Wound-healing efficacy was determined by measurements of wound contraction, histological analysis, and tensiometric method; moreover, anti-inflammatory, antibacterial, and acute dermal toxicity (OECD 402) were also evaluated. Phenol, resorcinol, conjugated resorcinol, and mangiferin were detected. TPC, TFC, and SA₅₀ were 136 mg GAE/g, 101.66 mg QE/g, and 36.33 µg/mL, respectively. Tensile strength and wound contraction closure did not show significant differences between MEMI and dexpanthenol groups. Histological analysis (after 14 days) shows a similar architecture between MEMI treatment and normal skin. MEMI exhibits a reduction in edema. Staphylococcus epidermidis had an MIC of 2 mg/mL, while Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli reached 4 mg/mL. The MEMI showed no signs of toxicity. Therefore, this study demonstrates multiple targets that flavonoids and mangiferin of MEMI may present during the healing process.

Infection Probability Index: Implementation of an Automated Chronic Wound Infection Marker

The number of people suffering from chronic wounds is increasing due to demographic changes and the global epidemics of obesity and diabetes. Innovative imaging techniques within the field of chronic wound diagnostics are required to improve wound care by predicting and detecting wound infections to accelerate the application of treatments. For this reason, the infection probability index (IPI) is introduced as a novel infection marker based on thermal wound imaging. To improve usability, the IPI was implemented to automate scoring. Visual and thermal image pairs of 60 wounds were acquired to test the implemented algorithms on clinical data. The proposed process consists of (1) determining various parameters of the IPI based on medical hypotheses, (2) acquiring data, (3) extracting camera distortions using camera calibration, and (4) preprocessing and (5) automating segmentation of the wound to calculate (6) the IPI. Wound segmentation is reviewed by user input, whereas the segmented area can be refined manually. Furthermore, in addition to proof of concept, IPIs’ correlation with C-reactive protein (CRP) levels as a clinical infection marker was evaluated. Based on average CRP levels, the patients were clustered into two groups, on the basis of the separation value of an averaged CRP level of 100. We calculated the IPIs of the 60 wound images based on automated wound segmentation. Average runtime was less than a minute. In the group with lower average CRP, a correlation between IPI and CRP was evident.

Does Probiotic Consumption Enhance Wound Healing? A Systematic Review

The use of probiotics is one of the emerging lines of treatment for wound healing. This systematic review aimed to summarize currently available evidence on the effect of oral or enteral probiotic therapy on skin or oral mucosal wound healing in humans. To verify the developments in this field and the level of available scientific evidence, we applied a broad search strategy with no restrictions on wound type, target population, probiotic strain, or intervention protocol used. This review included seven studies involving 348 individuals. Four studies reported positive outcomes for healing improvement after probiotic therapy, and none of the studies reported adverse effects or a marked increase in wound healing time. The positive or neutral results observed do not generate strong evidence regarding the effectiveness of probiotics for wound healing. However, they suggest a promising field for future clinical research where the probiotic strains used, type of wounds, and target population are controlled for.

Culturomics revealed the bacterial constituents of the microbiota of a 10-year-old laboratory culture of planarian species S. mediterranea

The planarian species Schmidtea mediterranea is a flatworm living in freshwater that is used in the research laboratory as a model to study developmental and regeneration mechanisms, as well as antibacterial mechanisms. However, the cultivable microbial repertoire of the microbes comprising its microbiota remains unknown. Here, we characterized the bacterial constituents of a 10-year-old laboratory culture of planarian species S. mediterranea via culturomics analysis. We isolated 40 cultivable bacterial species, including 1 unidentifiable species. The predominant phylum is Proteobacteria, and the most common genus is Pseudomonas. We discovered that parts of the bacterial flora of the planarian S. mediterranea can be classified as fish pathogens and opportunistic human pathogens.

Retained Negative Pressure Wound Therapy Foams as a Cause of Infection Persistence

Significance: Negative pressure wound therapy (NPWT) has become a valuable adjunct in the treatment of acute and chronic wounds in several surgical disciplines. Retained foams are among its side effects, and they pose a rare but devastating complication at the site of this therapy, which might be associated with wound-healing complications, infection persistence, repeated surgical revisions, and prolonged antibiotic courses. Recent Advances: In the past 15 years, an increasing number of studies have identified this potential problem. Although the exact incidence remains unknown, initial studies have indicated rates of up to 10% in large collectives being treated by NPWT. Critical Issues: The lack of radiopaque markers does not allow for the visual control of retained foams using plain radiographs. Further imaging methods (e.g., CT and MRI) also do not help in adequate differential diagnosis. The lack of routine documentation of the number, type, and localization of the inserted foam(s) and unplanned surgery with a different surgical team pose risk factors for foam retainment. Future Directions: Introducing new documentation records for wounds treated with NPWT is recommended. At foam removal, all dressing materials should be examined for integrity. The development of foams with radiopaque markers by the industry, such as those routinely used in surgical gauze swabs, might also be a useful step to minimize the risk of foam retainment within wounds.

Current Insights: The Impact of Gut Microbiota on Postoperative Complications in Visceral Surgery-A Narrative Review

Postoperative complications are a major problem occurring in up to 50% of patients undergoing major abdominal surgery. Occurrence of postoperative complications is associated with a significantly higher morbidity and mortality in affected patients. The most common postoperative complications are caused by an infectious genesis and include anastomotic leakage in case of gastrointestinal anastomosis and surgical site infections. Recent research highlighted the importance of gut microbiota in health and disease. It is plausible that the gut microbiota also plays a pivotal role in the development of postoperative complications. This narrative review critically summarizes results of recent research in this particular field. The review evaluates the role of gut microbiota alteration in postoperative complications, including postoperative ileus, anastomotic leakage, and surgical site infections in visceral surgery. We tried to put a special focus on a potential diagnostic value of pre- and post-operative gut microbiota sampling showing that recent data are inhomogeneous to identify a high-risk microbial profile for development of postoperative complications.

A Trifecta of New Insights into Ovine Footrot for Infection Drivers, Immune Response, and Host-Pathogen Interactions

Footrot is a polymicrobial infectious disease in sheep causing severe lameness, leading to one of the industry's largest welfare problems. The complex etiology of footrot makes in situ or in vitro investigations difficult. Computational methods offer a solution to understanding the bacteria involved and how they may interact with the host, ultimately providing a way to identify targets for future hypothesis-driven investigative work. Here, we present the first combined global analysis of bacterial community transcripts together with the host immune response in healthy and diseased ovine feet during a natural polymicrobial infection state using metatranscriptomics. The intratissue and surface bacterial populations and the most abundant bacterial transcriptomes were analyzed, demonstrating that footrot-affected skin has reduced diversity and increased abundances of not only the causative bacterium Dichelobacter nodosus but also other species such as Mycoplasma fermentans and Porphyromonas asaccharolytica. Host transcriptomics reveals the suppression of biological processes related to skin barrier function, vascular functions, and immunosurveillance in unhealthy interdigital skin, supported by histological findings that type I collagen (associated with scar tissue formation) is significantly increased in footrot-affected interdigital skin compared to outwardly healthy skin. Finally, we provide some interesting indications of host and pathogen interactions associated with virulence genes and the host spliceosome, which could lead to the identification of future therapeutic targets.

Capturing the RNA castle: Exploiting MicroRNA inhibition for wound healing

The growing pipelines of RNA-based therapies herald new opportunities to deliver better patient outcomes for complex disorders such as chronic nonhealing wounds associated with diabetes. Members of the microRNA (miRNA) family of small noncoding RNAs have emerged as targets for diverse elements of cutaneous wound repair, and both miRNA enhancement with mimics or inhibition with antisense oligonucleotides represent tractable approaches for miRNA-directed wound healing. In this review, we focus on miRNA inhibition strategies to stimulate skin repair given advances in chemical modifications to enhance the performance of antisense miRNA (anti-miRs). We first explore miRNAs whose inhibition in keratinocytes promotes keratinocyte migration, an essential part of re-epithelialisation during wound repair. We then focus on miRNAs that can be targeted for inhibition in endothelial cells to promote neovascularisation for wound healing in the context of diabetic mouse models. The picture that emerges is that direct comparisons of different anti-miRNAs modifications are required to establish the most translationally viable options in the chronic wound environment, that direct comparisons of the impact of inhibition of different miRNAs are needed to quantify and rank their relative efficacies in promoting wound repair, and that a standardised human ex vivo model of the diabetic wound is needed to reduce reliance on mouse models that do not necessarily enhance mechanistic understanding of miRNA-targeted wound healing.

Biofilms in Diabetic Foot Ulcers: Impact, Risk Factors and Control Strategies

Diabetic foot ulcers (DFUs) are a serious complication from diabetes mellitus, with a huge economic, social and psychological impact on the patients' life. One of the main reasons why DFUs are so difficult to heal is related to the presence of biofilms. Biofilms promote wound inflammation and a remarkable lack of response to host defences/treatment options, which can lead to disease progression and chronicity. In fact, appropriate treatment for the elimination of these microbial communities can prevent the disease evolution and, in some cases, even avoid more serious outcomes, such as amputation or death. However, the detection of biofilm-associated DFUs is difficult due to the lack of methods for diagnostics in clinical settings. In this review, the current knowledge on the involvement of biofilms in DFUs is discussed, as well as how the surrounding environment influences biofilm formation and regulation, along with its clinical implications. A special focus is also given to biofilm-associated DFU diagnosis and therapeutic strategies. An overview on promising alternative therapeutics is provided and an algorithm considering biofilm detection and treatment is proposed.

Improvement of Cutaneous Wound Healing via Topical Application of Heat-Killed Lactococcus chungangensis CAU 1447 on Diabetic Mice

Cutaneous wound healing comprises a complex systemic network. Probiotics, naturally extracted substances, medicine, and chemical compounds have been used for wound healing, but the application of postbiotics as therapeutic agents has yet to be explored. Our study shows potential beneficial effects of heat-killed Lactococcus chungangensis CAU 1447 on type 1 diabetic mice. The postbiotic strain significantly decreased the skin wound size. The activity of myeloperoxidase secreted from neutrophils also decreased. The molecular mechanism of wound healing was adjusted by important mediators, growth factors, chemokines, and cytokines. These elements regulated the anti-inflammatory activity and accelerated wound healing. To determine the role of the postbiotic in wound repair, we showed a similar taxonomic pattern as compared to the diabetic mice using skin microbiome analysis. These findings demonstrated that heat-killed Lactococcus chungangensis CAU 1447 had beneficial effects on wound healing and can be utilized as postbiotic therapeutic agents.

Skin Wound Healing Rate in Fish Depends on Species and Microbiota

The skin is a barrier between the body and the environment that protects the integrity of the body and houses a vast microbiota. By interacting with the host immune system, the microbiota improves wound healing in mammals. However, in fish, the evidence of the role of microbiota and the type of species on wound healing is scarce. We aimed to examine the wound healing rate in various fish species and evaluate the effect of antibiotics on the wound healing process. The wound healing rate was much faster in two of the seven fish species selected based on habitat and skin types. We also demonstrated that the composition of the microbiome plays a role in the wound healing rate. After antibiotic treatment, the wound healing rate improved in one species. Through 16S rRNA sequencing, we identified microbiome correlates of varying responses on wound healing after antibiotic treatment. These findings indicate that not only the species difference but also the microbiota play a significant role in wound healing in fish.

Ear wound healing in MRL/MpJ mice is associated with gut microbiome composition and is transferable to non-healer mice via microbiome transplantation

OBJECTIVE

Adult elastic cartilage has limited repair capacity. MRL/MpJ (MRL) mice, by contrast, are capable of spontaneously healing ear punctures. This study was undertaken to characterize microbiome differences between healer and non-healer mice and to evaluate whether this healing phenotype can be transferred via gut microbiome transplantation.

METHODS

We orally transplanted C57BL/6J (B6) mice with MRL/MpJ cecal contents at weaning and as adults (n = 57) and measured ear hole closure 4 weeks after a 2.0mm punch and compared to vehicle-transplanted MRL and B6 (n = 25) and B6-transplanted MRL (n = 20) mice. Sex effects, timing of transplant relative to earpunch, and transgenerational heritability were evaluated. In a subset (n = 58), cecal microbiomes were profiled by 16S sequencing and compared to ear hole closure. Microbial metagenomes were imputed using PICRUSt.

RESULTS

Transplantation of B6 mice with MRL microbiota, either in weanlings or adults, improved ear hole closure. B6-vehicle mice healed ear hole punches poorly (0.25±0.03mm, mm ear hole healing 4 weeks after a 2mm ear hole punch [2.0mm-final ear hole size], mean±SEM), whereas MRL-vehicle mice healed well (1.4±0.1mm). MRL-transplanted B6 mice healed roughly three times as well as B6-vehicle mice, and half as well as MRL-vehicle mice (0.74±0.05mm, P = 6.9E-10 vs. B6-vehicle, P = 5.2E-12 vs. MRL-vehicle). Transplantation of MRL mice with B6 cecal material did not reduce MRL healing (B6-transplanted MRL 1.3±0.1 vs. MRL-vehicle 1.4±0.1, p = 0.36). Transplantation prior to ear punch was associated with the greatest ear hole closure. Offspring of transplanted mice healed significantly better than non-transplanted control mice (offspring:0.63±0.03mm, mean±SEM vs. B6-vehicle control:0.25±0.03mm, n = 39 offspring, P = 4.6E-11). Several microbiome clades were correlated with healing, including Firmicutes (R = 0.84, P = 8.0E-7), Lactobacillales (R = 0.65, P = 1.1E-3), and Verrucomicrobia (R = -0.80, P = 9.2E-6). Females of all groups tended to heal better than males (B6-vehicle P = 0.059, MRL-transplanted B6 P = 0.096, offspring of MRL-transplanted B6 P = 0.0038, B6-transplanted MRL P = 1.6E-6, MRL-vehicle P = 0.0031). Many clades characteristic of female mouse cecal microbiota vs. males were the same as clades characteristic of MRL and MRL-transplanted B6 mice vs. B6 controls, including including increases in Clostridia and reductions in Verrucomicrobia in female mice.

CONCLUSION

In this study, we found an association between the microbiome and tissue regeneration in MRL mice and demonstrate that this trait can be transferred to non-healer mice via microbiome transplantation. We identified several microbiome clades associated with healing.

The Effect of Burn Resuscitation Volumes on the Gut Microbiome in a Swine Model

INTRODUCTION

While recent reports underscore the significance of the gut microbiome (GM) in health and disease, its importance in burn outcomes remains unclear. Moreover, aggressive intravenous (IV) fluid resuscitation of patients may alter intestinal flora. Herein, we describe GM changes following a large burn in swine randomized to different volumes of IV Lactated Ringers' (LR).

METHODS

Anesthetized Yorkshire swine sustained 40% total body surface area full-thickness burns and were randomized to different volumes of IV LR: none (n = 5), 15 mL/kg/d (low; n = 6), or 80 mL/kg/d (high; n = 6). At baseline and days 1 and 2, fecal swabs were collected for 16s rDNA sequencing. Proximal jejunum was collected immediately after euthanasia (day 2) for western blot, histopathology, and cytokine analyses.

RESULTS

Burns produced significant shifts in β-diversity and non-significant reductions in α-diversity that did not recover regardless of treatment group. Burn-induced increases in Proteobacteria and decreases in Firmicutes were attenuated by IV fluids in a dose-dependent manner, and also correlated with α-diversity. IV fluids caused a dose-dependent increase in Bacteroides and prevented a transient increase in the opportunistic pathogen Haemophilus parainfluenzae. While high volumes of IV fluids increased intestinal Hsp70 levels (P = 0.0464), they reduced SGLT1 (P = 0.0213) and caspase3 (P = 0.0139) levels. IV fluids elicited a non-specific cytokine response; however, Bacteroidetes levels correlated with intestinal IL18 levels (P = 0.0166, R = 0.4201).

CONCLUSIONS

We present the first report on the gut microbiome in a porcine burn model, and present data to suggest that IV fluids may influence GM and gut functional proteins following a burn. Overall, burn-induced GM diversity shifts may expose diagnostic and/or therapeutic targets to improve outcomes.

Method development and characterisation of the low-molecular-weight peptidome of human wound fluids

The normal wound healing process is characterised by proteolytic events, whereas infection results in dysfunctional activations by endogenous and bacterial proteases. Peptides, downstream reporters of these proteolytic actions, could therefore serve as a promising tool for diagnosis of wounds. Using mass-spectrometry analyses, we here for the first time characterise the peptidome of human wound fluids. Sterile post-surgical wound fluids were found to contain a high degree of peptides in comparison to human plasma. Analyses of the peptidome from uninfected healing wounds and Staphylococcus aureus -infected wounds identify unique peptide patterns of various proteins, including coagulation and complement factors, proteases, and antiproteinases. Together, the work defines a workflow for analysis of peptides derived from wound fluids and demonstrates a proof-of-concept that such fluids can be used for analysis of qualitative differences of peptide patterns from larger patient cohorts, providing potential biomarkers for wound healing and infection.

The Insights of Microbes' Roles in Wound Healing: A Comprehensive Review

A diverse range of normal flora populates the human skin and numbers are relatively different between individuals and parts of the skin. Humans and normal flora have formed a symbiotic relationship over a period of time. With numerous disease processes, the interaction between the host and normal flora can be interrupted. Unlike normal wound healing, which is complex and crucial to sustaining the skin’s physical barrier, chronic wounds, especially in diabetes, are wounds that fail to heal in a timely manner. The conditions become favorable for microbes to colonize and establish infections within the skin. These include secretions of various kinds of molecules, substances or even trigger the immune system to attack other cells required for wound healing. Additionally, the healing process can be slowed down by prolonging the inflammatory phase and delaying the wound repair process, which causes further destruction to the tissue. Antibiotics and wound dressings become the targeted therapy to treat chronic wounds. Though healing rates are improved, prolonged usage of these treatments could become ineffective or microbes may become resistant to the treatments. Considering all these factors, more studies are needed to comprehensively elucidate the role of human skin normal flora at the cellular and molecular level in a chronic injury. This article will review wound healing physiology and discuss the role of normal flora in the skin and chronic wounds.

Bioaerogels: Promising Nanostructured Materials in Fluid Management, Healing and Regeneration of Wounds

Wounds affect one's quality of life and should be managed on a patient-specific approach, based on the particular healing phase and wound condition. During wound healing, exudate is produced as a natural response towards healing. However, excessive production can be detrimental, representing a challenge for wound management. The design and development of new healing devices and therapeutics with improved performance is a constant demand from the healthcare services. Aerogels can combine high porosity and low density with the adequate fluid interaction and drug loading capacity, to establish hemostasis and promote the healing and regeneration of exudative and chronic wounds. Bio-based aerogels, i.e., those produced from natural polymers, are particularly attractive since they encompass their intrinsic chemical properties and the physical features of their nanostructure. In this work, the emerging research on aerogels for wound treatment is reviewed for the first time. The current scenario and the opportunities provided by aerogels in the form of films, membranes and particles are identified to face current unmet demands in fluid managing and wound healing and regeneration.

Enterococcus faecium L-15 Extract Enhances the Self-Renewal and Proliferation of Mouse Skin-Derived Precursor Cells

Lactic acid bacteria (LAB) in the gastrointestinal tract have beneficial health effects. LAB activate the proliferation of intestinal stem cells and speed the recovery of damaged intestinal cells, but little is known about effect of LAB on other adult stem cells. In this study, a cell-free extract of Enterococcus faecium L-15 (L15) was exposed to mouse skin-derived precursor cells (SKPs), and the changes in characteristics associated with proliferation and self-renewal capacity were investigated. L15 increased the size of the spheres and the proliferation rate of SKPs. Cell cycle analysis revealed that cells in the S-phase increased after treatment with L15. In the L15-treated group, the total number of spheres significantly increased. The expression level of pluripotency marker genes also increased, while the mesenchymal lineage-related differentiation marker genes significantly decreased in the L15-treated group. The PI3K/Akt signaling pathway was activated by L15 in SKPs. These results indicate that L15 enhances proliferation and self-renewal of SKPs and may be used as a supplement for stem cell maintenance or application of stem cell therapy. This is the first report to investigate the functional effects of E. faecium on the proliferation and self-renewal capacity of SKPs.

A novel chronic wound biofilm model sustaining coexistence of Pseudomonas aeruginosa and Staphylococcus aureus suitable for testing of antibiofilm effect of antimicrobial solutions and wound dressings

Chronic wounds are a large burden to patients and healthcare systems. Biofilm infections in chronic wounds are crucial factors leading to non‐healing of wounds. It is important to study biofilm in wounds and to develop effective interventions against wound biofilm. This study presents a novel in vitro biofilm model mimicking infected chronic wounds. The novel layered chronic wound biofilm model uses woundlike media and includes both Pseudomonas aeruginosa and Staphylococcus aureus, which have been identified as the most important pathogens in wounds. The model sustains their coexistence for at least 96 h. Microscopy of the model revealed microbial growth in non‐surface attached microcolonies as previously observed in vivo. The model was used to determine log₁₀‐reduction for the use of an antimicrobial solution and antimicrobial dressings (containing silver or honey) showing moderate‐to‐low antibiofilm effect, which indicates better concordance with the observed clinical performance of this type of treatment than other widely used standard tests.

The classical and potential novel healthy functions of rice bran protein and its hydrolysates

Rice bran protein (RBP) is a plant protein obtained from rice bran, a byproduct produced during rice milling process. It has been proved to be a high quality protein due to containing all of the essential amino acids and the content closing to the FAO/WHO recommended ideal pattern. Recent studies indicated that RBP and rice bran protein hydrolysates (RBPH) served variety biological functions. In this review, we summarized the classical functions of RBP and RBPH mediating antioxidant activity, chronic diseases prevention (such as antihypertensive effect, anti-diabetic effect, cholesterol-lowering activity), and anti-cancer effect. We also proposed their potential novel functions on anti-obesity effect, attenuating sarcopenia, promoting wound healing. Furthermore, the potential benefit to coronavirus disease 2019 (COVID-19) patients was put forward, which might provide new strategy for development and utilization of RBP and RBPH.

Acute Radiation Syndrome and the Microbiome: Impact and Review

Study of the human microbiota has been a centuries-long endeavor, but since the inception of the National Institutes of Health (NIH) Human Microbiome Project in 2007, research has greatly expanded, including the space involving radiation injury. As acute radiation syndrome (ARS) is multisystemic, the microbiome niches across all areas of the body may be affected. This review highlights advances in radiation research examining the effect of irradiation on the microbiome and its potential use as a target for medical countermeasures or biodosimetry approaches, or as a medical countermeasure itself. The authors also address animal model considerations for designing studies, and the potential to use the microbiome as a biomarker to assess radiation exposure and predict outcome. Recent research has shown that the microbiome holds enormous potential for mitigation of radiation injury, in the context of both radiotherapy and radiological/nuclear public health emergencies. Gaps still exist, but the field is moving forward with much promise.

Examining the effect of wound cleansing on the microbiome of venous stasis ulcers

Common treatment for venous leg wounds includes topical wound dressings with compression. At each dressing change, wounds are debrided and washed; however, the effect of the washing procedure on the wound microbiome has not been studied. We hypothesized that wound washing may alter the wound microbiome. To characterize microbiome changes with respect to wound washing, swabs from 11 patients with chronic wounds were sampled before and after washing, and patient microbiomes were characterized using 16S rRNA sequencing and culturing. Microbiomes across patient samples prior to washing were typically polymicrobial but varied in the number and type of bacterial genera present. Proteus and Pseudomonas were the dominant genera in the study. We found that washing does not consistently change microbiome diversity but does cause consistent changes in microbiome composition. Specifically, washing caused a decrease in the relative abundance of the most highly represented genera in each patient cluster. The finding that venous leg ulcer wound washing, a standard of care therapy, can induce changes in the wound microbiome is novel and could be potentially informative for future guided therapy strategies.

Staphylococcus aureus Specific Electrospun Wound Dressings: Influence of Immobilization Technique on Antibacterial Efficiency of Novel Enzybiotic

The spread of antimicrobial resistance requires the development of novel strategies to combat superbugs. Bacteriolytic enzymes (enzybiotics) that selectively eliminate pathogenic bacteria, including resistant strains and biofilms, are attractive alternatives to antibiotics, also as a component of a new generation of antimicrobial wound dressings. AuresinePlus is a novel, engineered enzybiotic effective against Staphylococcus aureus-one of the most common pathogenic bacteria, found in infected wounds with a very high prevalence of antibiotic resistance. We took advantage of its potent lytic activity, selectivity, and safety to prepare a set of biodegradable PLGA/chitosan fibers generated by electrospinning. Our aim was to produce antimicrobial nonwovens to deliver enzybiotics directly to the infected wound and better control its release and activity. Three different methods of enzyme immobilization were tested: physical adsorption on the previously hydrolyzed surface, and covalent bonding formation using N-hydroxysuccinimide/N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide (NHS/EDC) or glutaraldehyde (GA). The supramolecular structure and functional properties analysis revealed that the selected methods resulted in significant development of nanofibers surface topography resulting in an efficient enzybiotic attachment. Both physically adsorbed and covalently bound enzymes (by NHS/EDC method) exhibited prominent antibacterial activity. Here, we present the extensive comparison between methods for the effective attachment of the enzybiotic to the electrospun nonwovens to generate biomaterials effective against antibiotic-resistant strains. Our intention was to present a comprehensive proof-of-concept study for future antimicrobial wound dressing development.

The skin microbiota in equine pastern dermatitis: a case-control study of horses in Switzerland

Background

Equine pastern dermatitis (EPD), a multifactorial syndrome, manifests as skin lesions of variable severity in the pastern area. Despite the widespread use of antibacterial therapy for treating this condition, little is known about the contributing bacteria.

Hypothesis/Objectives

To investigate the bacterial skin microbiota in EPD‐affected and unaffected (control) pasterns.

Animals

Case‐control study with 80 client‐owned horses; each with at least one EPD‐affected and one control pastern.

Methods and materials

Horses were grouped by the form of EPD (mild, exudative or proliferative), the assigned severity grade and type of pretreatment (disinfectant, topical antibacterial or no antibacterial pretreatment). Skin swabs were obtained, and the microbiota composition was compared between the groups.

Results

Bacterial alpha diversity was reduced in affected pasterns (P < 0.001) and this reduction was significantly associated with the EPD forms (P < 0.001), and not with the type of pretreatment (P > 0.14). Analyses of beta‐diversity confirmed a disordering of the skin microbiota (P = 0.004) in affected versus control pasterns, that was particularly profound in more severe lesions. The type of pretreatment was not significantly associated with this disordering. Four differentially abundant families were detected, of which Staphylococcaceae was the most distinct. The relative abundance of staphylococci was significantly increased in affected pasterns (P = 0.011), particularly in those that had received antibacterial treatment previously.

Conclusions and clinical relevance

Changes in the microbiota are associated with the EPD form or severity of lesions. The role of bacteria in the pathogenesis of EPD as well as the propriety and consequences of antibacterial treatment should therefore be further investigated.

Evidence for cutaneous dysbiosis in dystrophic epidermolysis bullosa

BACKGROUND

The human microbiome project addresses the relationship between bacterial flora and the human host, in both healthy and diseased conditions. The skin is an ecosystem with multiple niches, each featuring unique physiological conditions and thus hosting different bacterial populations. The skin microbiome has been implicated in the pathogenesis of many dermatoses. Given the role of dysbiosis in the pathogenesis of inflammation, which is prominent in dystrophic epidermolysis bullosa (DEB), we undertook a study on the skin microbiome.

AIM

To characterize the skin microbiome in a series of patients with DEB.

METHODS

This was a case-control study of eight patients with DEB and nine control cases enrolled between June 2017 and November 2018. The skin of patients with DEB was sampled at three different sites: untreated wound, perilesional skin and normal-appearing (uninvolved) skin. Normal skin on the forearm was sampled from age-matched healthy controls (HCs). We used a dedicated DNA extraction protocol to isolate microbial DNA, which was then analysed using next-generation microbial 16S rRNA sequencing. Data were analysed using a series of advanced bioinformatics tools.

RESULTS

The wounds, perilesional and uninvolved skin of patients with DEB demonstrated reduced bacterial diversity compared with HCs, with the flora in DEB wounds being the least diverse. We found an increased prevalence of staphylococci species in the lesional and perilesional skin of patients with DEB, compared with their uninvolved, intact skin. Similarly, the uninvolved skin of patients with DEB displayed increased staphylococcal content and significantly different microbiome diversities (other than staphylococci) compared with HC skin.

CONCLUSIONS

These findings suggest the existence of a unique DEB-associated skin microbiome signature, which could be targeted by specific pathogen-directed therapies. Moreover, altering the skin microbiome with increasing colonization of bacteria associated with nonchronic wounds may potentially facilitate wound healing in patients with DEB.

The Microbiome and Metabolome of Malignant Fungating Wounds: A Systematic Review of the Literature From 1995 to 2020

PURPOSE

Malignant fungating wounds (MFWs) afflict up to 14% of patients with advanced cancer. The bacterial community structures of MFW may influence the development and severity of wound symptoms. The purpose of this systematic review was to evaluate existing evidence regarding the relationship between microbiome and symptoms of MFWs.

METHODS

A systematic review of the published literature from January 1995 to January 2020 was conducted. An established quality assessment tool was used to assess the quality of the included studies.

SEARCH STRATEGY

We searched 4 major electronic databases and retrieved 724 articles; 7 met inclusion criteria.

FINDINGS/CONCLUSIONS

Seven studies were included; the overall quality of the included 7 studies was ranked as adequate. Findings from the studies provided an incomplete characterization of the microbiome and metabolome of MFW; none included modern genomic technologies. Twenty different species of aerobes and 14 species of anaerobes were identified, with inconsistent identification of biofilms and multi-drug-resistant bacteria. Symptom occurrence increased with the number of bacteria species (P = .0003) and the presence of at least 1 anaerobe (P = .0006) in malignant wound beds. Cancer wound-derived odor was associated with dimethyl trisulfide and 4 fatty acid volatiles. Periwound and moisture-associated skin damage were associated with higher putrescine levels in exudates.

IMPLICATIONS

Understanding the role of microbiota of MFW in developing or amplifying the severity of wound symptoms is the first step toward development of more precise and effective topical interventions.

Negative pressure wound therapy promotes wound healing by suppressing macrophage inflammation in diabetic ulcers

Aim: This work aims to explore the biological role of negative pressure wound therapy (NPWT) in the treatment of diabetic ulcer. Materials & methods: Full-thickness skin defects were created in diabetic (db/db) and non diabetic (db/m) mice to create wound models. The mice were received NPWT or rapamycin injection. Mouse macrophage cells (Raw264.7) were treated with lipopolysaccharide to induce inflammatory response, and then received negative pressure treatment. We observed the wound healing of mice and examined gene and protein expression and CD68⁺ macrophage levels. Results: NPWT notably enhanced the wound closure ratio, and inhibited the LC3-II/LC3-I ratio and Beclin-1 expression in diabetes mellitus (DM) mice. NPWT decreased CD68⁺ macrophage levels in wound tissues of DM mice. The influence conferred by NPWT was abolished by rapamycin treatment. Negative pressure repressed the LC3-II/LC3-I ratio and the expression of Beclin-1, TNF-α, IL-6 and IL-1β in the Raw264.7 cells. Conclusion: NPWT promotes wound healing by suppressing autophagy and macrophage inflammation in DM.

ICAM-1 deletion delays the repair process in aging diabetic mice

BACKGROUND

The delayed repair process in the aging diabetic population is becoming an alarming public health concern. ICAM-1 plays an important role in orchestrating the repair process by mediating neutrophil recruitment and phagocytosis. However, little is known about the role of ICAM-1 in aging diabetic repair.

METHODS

By causing injury in aging diabetic mice with ICAM-1 deletion (AD-ICAM-1^-/-), we found that AD-ICAM-1^-/- mice exhibited a delayed repair process with incomplete re-epithelialization and reduced angiogenesis. Additionally, high-throughput Illumina sequencing was performed to evaluate the microbiota of such mice.

RESULTS

The results indicate that the microbiota of the AD-ICAM-1^-/- injury site differed taxonomically at both the phylum and genus levels. Neutrophil recruitment and phagocytic function were also reduced in the AD-ICAM-1^-/- group. Notably, major inflammatory biomarker expression was also detected in AD-ICAM-1^-/- injured tissue.

CONCLUSIONS

Overall, this study demonstrated that AD-ICAM-1^-/- mice exhibit delayed repair. In addition, neutrophil recruitment and phagocytic activity were impaired in the AD-ICAM-1^-/- group, which may have allowed microbes to colonize the injury site.

The Skin Interactome: A Holistic "Genome-Microbiome-Exposome" Approach to Understand and Modulate Skin Health and Aging

Higher demands on skin care cosmetic products for strong performance drive intense research to understand the mechanisms of skin aging and design strategies to improve overall skin health. Today we know that our needs and influencers of skin health and skin aging change throughout our life journey due to both extrinsic factors, such as environmental factors and lifestyle factors, as well as our intrinsic factors. Furthermore, we need to consider our microflora, a collection of micro-organisms such as bacteria, viruses, and fungi, which is a living ecosystem in our gut and on our skin, that can have a major impact on our health. Here, we are viewing a holistic approach to understand the collective effect of the key influencers of skin health and skin aging both reviewing how each of them impact the skin, but more importantly to identify molecular conjunction pathways of these different factors in order to get a better understanding of the integrated “genome-microbiome-exposome” effect. For this purpose and in order to translate molecularly the impact of the key influencers of skin health and skin aging, we built a digital model based on system biology using different bioinformatics tools. This model is considering both the positive and negative impact of our genome (genes, age/gender), exposome: external (sun, pollution, climate) and lifestyle factors (sleep, stress, exercise, nutrition, skin care routine), as well as the role of our skin microbiome, and allowed us in a first application to evaluate the effect of the genome in the synthesis of collagen in the skin and the determination of a suitable target for boosting pro-collagen synthesis. In conclusion, we have, through our digital holistic approach, defined the skin interactome concept, as an advanced tool to better understand the molecular genesis of skin aging and further develop a strategy to balance the influence of the exposome and microbiome to protect, prevent, and delay the appearance of skin aging signs and preserve good skin health condition. In addition, this model will aid in identifying and optimizing skin treatment options based on external triggers, as well as helping to design optimal treatments modulating the intrinsic pathways.

Therapeutic Potential of Cannabidiol (CBD) for Skin Health and Disorders

Though there is limited research confirming the purported topical benefits of cannabinoids, it is certain that cutaneous biology is modulated by the human endocannabinoid system (ECS). Receptors from the ECS have been identified in the skin and systemic abuse of synthetic cannabinoids, and their analogs, have also been associated with the manifestation of dermatological disorders, indicating the effects of the ECS on cutaneous biology. In particular, cannabidiol (CBD), a non-psychoactive compound from the cannabis plant, has garnered significant attention in recent years for its anecdotal therapeutic potential for various pathologies, including skin and cosmetic disorders. Though a body of preclinical evidence suggests topical application of CBD may be efficacious for some skin disorders, such as eczema, psoriasis, pruritis, and inflammatory conditions, confirmed clinical efficacy and elucidation of underlying molecular mechanisms have yet to be fully identified. This article provides an update on the advances in CBD research to date and the potential areas of future exploration.

PREVALENCE OF HEARING SYMPTOMS RELATED TO PATULOUS EUSTACHIAN TUBE AFTER BARIATRIC SURGERY

Background:

Rapid and severe weight loss can result in the reduction of the ear tube lining fat tissue and it becomes patent, leading to symptoms such as autophony, aural fullness and tinnitus. Patients after bariatric surgery have, in theory, a predisposition to the development of such alteration.

Aim:

To evaluate the presence of patent tuba-related complaints in patients undergoing bariatric surgery, correlating with weight and body mass index (BMI) values, as well as demographic data.

Methods:

Cross-sectional study composed of the evaluation of patients undergoing bariatric surgery through a standardized questionnaire about the presence of symptoms compatible with ear tube patency.

Results:

Eighty patients were evaluated, 77 female and three males. The main comorbidity was systemic arterial hypertension (37.5%). Fifteen (18.75%) presented symptoms compatible with patent auditory/Eustachian tube - aural fullness and autophony - postoperatively. In symptomatic individuals the initial weight was 112 kg on average and the preoperative BMI was 45 kg/m², while in asymptomatic individuals the weight was 117 kg and BMI 47 kg/m². There was statistical significance in the comparison between individuals with and without symptoms in the variables of initial weight (p=0.00000), current weight (p=0.00029), preoperative BMI (p=0.00219) and postoperative BMI (p=0.00148).

Conclusion:

The presence of symptoms compatible with patent auditory/Eustachian tube was 18.75% of the patients submitted to bariatric surgery in the evaluated sample. Both preoperative weight and BMI were lower in symptomatic patients when compared with the asymptomatic group.

The Cutaneous Wound Innate Immunological Microenvironment

The skin represents the first line of defense and innate immune protection against pathogens. Skin normally provides a physical barrier to prevent infection by pathogens; however, wounds, microinjuries, and minor barrier impediments can present open avenues for invasion through the skin. Accordingly, wound repair and protection from invading pathogens are essential processes in successful skin barrier regeneration. To repair and protect wounds, skin promotes the development of a specific and complex immunological microenvironment within and surrounding the disrupted tissue. This immune microenvironment includes both innate and adaptive processes, including immune cell recruitment to the wound and secretion of extracellular factors that can act directly to promote wound closure and wound antimicrobial defense. Recent work has shown that this immune microenvironment also varies according to the specific context of the wound: the microbiome, neuroimmune signaling, environmental effects, and age play roles in altering the innate immune response to wounding. This review will focus on the role of these factors in shaping the cutaneous microenvironment and how this ultimately impacts the immune response to wounding.

Aloe vera: A Medicinal Plant Used in Skin Wound Healing

Skin injury is a major problem threatening human physical and mental health, and how to promote wound healing has been the focus. Developing new wound dressings is an important strategy in skin regeneration. Aloe vera is a medicinal plant with a long history, complex constituents, and various pharmacological activities. Many studies have shown that A. vera plays an important role in promoting wound healing. Adding A. vera to wound dressing has become an ideal way. This review will describe the process of skin injury and wound healing and analyze the role of A. vera in wound healing. In addition, the types of wound dressing and the applications of A. vera in wound dressing will be discussed.

Translational perspectives to treat Epidermolysis bullosa-Where do we stand?

Epidermolysis bullosa (EB) is the prototypical example of genetic skin fragility disorders. Genotypic heterogeneity, modifier genes, epigenetic, biochemical and environmental factors alter and determine pathogenic traits and, ultimately, the wide and striking phenotypic variability in EB. Besides the primary structural-functional defect, chronic tissue damage with induction and dysregulation of inflammatory pathways is a common pathogenic mechanism in EB. In localized variants, the inflammatory aberrations may mainly affect the micromilieu of lesional skin, while a systemic inflammatory response was shown to contribute to the systemic morbidity in severe EB subtypes with extensive cutaneous involvement. Our continued understanding of the pathophysiology of EB, as well as advances in molecular technologies, has paved the way for translational therapeutic approaches. The spectrum comprises of corrective and symptom-relieving therapies that include innovative therapeutic options garnered from the bench, repurposed drugs approved for other diseases, as well as strategies for gene-, protein- and cell-based therapies. Immunological traits further define new targets of therapy, aimed at improving skin barrier restoration, microbial surveillance and infection control, wound healing and anti-neoplastic effects. Clinical availability and feasibility of these approaches for all EB patients and subtypes are currently limited, reflecting issues of efficacy, specificity, tolerability and safety. A multistep targeting approach and highly individualized, risk-stratified combinatory treatment plans will thus be essential for sustained efficacy and improved overall quality of life in EB.

Biofilms in Diabetic Foot Ulcers: Significance and Clinical Relevance

Foot infections are the main disabling complication in patients with diabetes mellitus. These infections can lead to lower-limb amputation, increasing mortality and decreasing the quality of life. Biofilm formation is an important pathophysiology step in diabetic foot ulcers (DFU)-it plays a main role in the disease progression and chronicity of the lesion, the development of antibiotic resistance, and makes wound healing difficult to treat. The main problem is the difficulty in distinguishing between infection and colonization in DFU. The bacteria present in DFU are organized into functionally equivalent pathogroups that allow for close interactions between the bacteria within the biofilm. Consequently, some bacterial species that alone would be considered non-pathogenic, or incapable of maintaining a chronic infection, could co-aggregate symbiotically in a pathogenic biofilm and act synergistically to cause a chronic infection. In this review, we discuss current knowledge on biofilm formation, its presence in DFU, how the diabetic environment affects biofilm formation and its regulation, and the clinical implications.

Challenges and New Therapeutic Approaches in the Management of Chronic Wounds

Chronic non-healing wounds are estimated to cost the US healthcare $28-$31 billion per year. Diabetic ulcers, arterial and venous ulcers, and pressure ulcers are some of the most common types of chronic wounds. The burden of chronic wounds continues to rise due to the current epidemic of obesity and diabetes and the increase in elderly adults in the population who are more vulnerable to chronic wounds than younger individuals. This patient population is also highly vulnerable to debilitating infections caused by opportunistic and multi-drug resistant pathogens. Reduced microcirculation, decreased availability of cytokines and growth factors that promote wound closure and healing, and infections by multi-drug resistant and biofilm forming microbes are some of the critical factors that contribute to the development of chronic non-healing wounds. This review discusses novel approaches to understand chronic wound pathology and methods to improve chronic wound care, particularly when chronic wounds are infected by multi-drug resistant, biofilm forming microbes.

EFFECTS OF PROBIOTICS SUPPLEMENTATION ON SKIN WOUND HEALING IN DIABETIC RATS

Background:

Chronic wounds in patients with Diabetes Mellitus often become incurable due to prolonged and excessive production of inflammatory cytokines. The use of probiotics modifies the intestinal microbiota and modulates inflammatory reactions.

Aim:

To evaluate the influence of perioperative supplementation with probiotics in the cutaneous healing process in diabetic rats.

Methods:

Forty-six rats were divided into four groups (C3, P3, C10, P10) according to the treatment (P=probiotic or C=control, both orally administered) and day of euthanasia, 3^rd or 10^th postoperative days. All rats were induced to Diabetes Mellitus 72 h before starting the experiment with alloxan. Supplementation was initiated five days before the incision and maintained until euthanasia. Scalpel incision was guided by a 2x2 cm mold and the wounds were left to heal per second-intention. The wounds were digitally measured. Collagen densitometry was done with Picrosirius Red staining. Histological parameters were analyzed by staining by H&E.

Results:

The contraction of the wound was faster in the P10 group which resulted in a smaller scar area (p=0.011). There was an increase in type I collagen deposition from the 3^rd to the 10^th postoperative day in the probiotic groups (p=0.016), which did not occur in the control group (p=0.487). The histological analysis showed a better degree of healing in the P10 group (p=0.005), with fewer polymorphonuclear (p<0.001) and more neovessels (p=0.001).

Conclusions:

Perioperative supplementation of probiotics stimulates skin wound healing in diabetic rats, possibly due to attenuation of the inflammatory response and increased neovascularization and type I collagen deposition.