Normal cutaneous wound healing: clinical correlation with cellular and molecular events

Making Sense of Electrical Stimulation: A Meta-analysis for Wound Healing

Electrical stimulation as a mode of external enhancement factor in wound healing has been explored widely. It has proven to have multidimensional effects in wound healing including antibacterial, galvanotaxis, growth factor secretion, proliferation, transdifferentiation, angiogenesis, etc. Despite such vast exploration, this modality has not yet been established as an accepted method for treatment. This article reviews and analyzes the approaches of using electrical stimulation to modulate wound healing and discusses the incoherence in approaches towards reporting the effect of stimulation on the healing process. The analysis starts by discussing various processes adapted in in vitro, in vivo, and clinical practices. Later it is focused on in vitro approaches directed to various stages of wound healing. Based on the analysis, a protocol is put forward for reporting in vitro works in such a way that the outcomes of the experiment are replicable and scalable in other setups. This work proposes a ground of unification for all the in vitro approaches in a more sensible manner, which can be further explored for translating in vitro approaches to complex tissue stimulation to establish electrical stimulation as a controlled clinical method for modulating wound healing.

A system for bioelectronic delivery of treatment directed toward wound healing

The development of wearable bioelectronic systems is a promising approach for optimal delivery of therapeutic treatments. These systems can provide continuous delivery of ions, charged biomolecules, and an electric field for various medical applications. However, rapid prototyping of wearable bioelectronic systems for controlled delivery of specific treatments with a scalable fabrication process is challenging. We present a wearable bioelectronic system comprised of a polydimethylsiloxane (PDMS) device cast in customizable 3D printed molds and a printed circuit board (PCB), which employs commercially available engineering components and tools throughout design and fabrication. The system, featuring solution-filled reservoirs, embedded electrodes, and hydrogel-filled capillary tubing, is assembled modularly. The PDMS and PCB both contain matching through-holes designed to hold metallic contact posts coated with silver epoxy, allowing for mechanical and electrical integration. This assembly scheme allows us to interchange subsystem components, such as various PCB designs and reservoir solutions. We present three PCB designs: a wired version and two battery-powered versions with and without onboard memory. The wired design uses an external voltage controller for device actuation. The battery-powered PCB design uses a microcontroller unit to enable pre-programmed applied voltages and deep sleep mode to prolong battery run time. Finally, the battery-powered PCB with onboard memory is developed to record delivered currents, which enables us to verify treatment dose delivered. To demonstrate the functionality of the platform, the devices are used to deliver H[Formula: see text] in vivo using mouse models and fluoxetine ex vivo using a simulated wound environment. Immunohistochemistry staining shows an improvement of 35.86% in the M1/M2 ratio of H[Formula: see text]-treated wounds compared with control wounds, indicating the potential of the platform to improve wound healing.

Drug suspending during wound healing effectively weakens immunosuppression-related complications by preserving CD8+ T cell function

Immunosuppressive medications, which interfere with the activation and proliferation of T and B cells, increase the risk of wound healing complications. To address it, this study aimed to validate the feasibility of drug suspending during wound healing, whilst exploring the mechanisms exerted by T cells, which are important in the wound healing process. For this, a mouse skin wound model was set up. Tacrolimus (FK506) and fingolimod (FTY720) were both administered intraperitoneally prior to wounding to inhibit the T cell activation and migration, respectively. Flow-cytometric analysis subsequently revealed the functional T cell subtypes detected during the healing process. A CD8a antibody was also administered to deplete CD8+ T cells in vivo to verify their specific function. It was found that FK506 or FTY720 administration delayed the early phase of wound healing by reducing collagen production, which was also supported by the downregulation of col1a1, col3a1 and tgfb1. However, there was no significant difference in the total healing period. Both spleen- and skin-derived CD8+ T cells were proliferated and activated after injury without intervention, whereas CD4+ T cells showed no significant changes. Furthermore, selectively depleting CD8+ T cells retarded the healing process by downregulating collagen production-associated genes (col1a1, col3a1, tgfβ1 and en1) and proteins (collagen type 1 and 3). In addition, the CD8a antibody decreased the expression of genes lta, tnfa, il13 and il13ra, and protein interleukin-13Rα. In conclusion, suspending immunosuppressive drugs during wound healing was shown to be feasible through restraining the migration of activated T cells. CD8+ T cells represented the primary functional subtype positively associated with wound healing.

First-in-human clinical trial of allogeneic, platelet-derived extracellular vesicles as a potential therapeutic for delayed wound healing

The release of growth factors, cytokines and extracellular matrix modifiers by activated platelets is an important step in the process of healthy wound healing. Extracellular vesicles (EVs) released by activated platelets carry this bioactive cargo in an enriched form, and may therefore represent a potential therapeutic for the treatment of delayed wound healing, such as chronic wounds. While EVs show great promise in regenerative medicine, their production at clinical scale remains a critical challenge and their tolerability in humans is still to be fully established. In this work, we demonstrate that Ligand-based Exosome Affinity Purification (LEAP) chromatography can successfully isolate platelet EVs (pEVs) of clinical grade from activated platelets, which retain the regenerative properties of the parent cell. LEAP-isolated pEVs display the expected biophysical features of EV populations and transport essential proteins in wound healing processes, including insulin growth factor (IGF) and transforming growth factor beta (TGF-ß). In vitro studies show that pEVs induce proliferation and migration of dermal fibroblasts and increase dermal endothelial cells' angiogenic potential, demonstrating their wound healing potential. pEV treatment activates the ERK and Akt signalling pathways within recipient cells. In a first-in-human, double-blind, placebo-controlled, phase I clinical trial of healthy volunteer adults, designed primarily to assess safety in the context of wound healing, we demonstrate that injections of LEAP-purified pEVs in formulation buffer are safe and well tolerated (Plexoval II study, ACTRN12620000944932). As a secondary objective, biological activity in the context of wound healing rate was assessed. In this cohort of healthy participants, in which the wound bed would not be expected to be deficient in the bioactive cargo that pEVs carry, all wounds healed rapidly and completely and no difference in time to wound closure of the treated and untreated wounds was observed at the single dose tested. The outcomes of this study evidence that pEVs manufactured through the LEAP process can be injected safely in humans as a potential wound healing treatment, and warrant further study in clinical trials designed expressly to assess therapeutic efficacy in patients with delayed or disrupted wound healing.

The Role of Extracellular Matrix in Wound Healing

BACKGROUND

Extracellular matrix communicates with surrounding cells to maintain skin homeostasis and modulate multiple cellular processes including wound healing.

OBJECTIVE

To elucidate the dynamic composition and potential roles of extracellular matrix in normal skin, wound healing process, and abnormal skin scarring.

MATERIALS AND METHODS

Literature review was performed to identify relevant publications pertaining to the extracellular matrix deposition in normal skin and wound healing process, as well as in abnormal scars.

RESULTS

A summary of the matrix components in normal skin is presented. Their primary roles in hemostasis, inflammation, proliferation, and remodeling phases of wound healing are briefly discussed. Identification of novel extracellular matrix in keloids is also provided.

CONCLUSION

Abnormal scarring remains a challenging condition with unmet satisfactory treatments. Illumination of extracellular matrix composition and functions in wound healing process will allow for the development of targeted therapies in the future.

Arnica montana L. associated with microcurrent accelerates the dermis reorganisation of skin lesions

The aim of this study was to test the effect of electrical stimulation in association with topical Arnica montana gel on organisational changes in the dermis during tissue repair. An experimental rat incisional skin lesion was used for the study. This involved making an incisional lesion on the dorsum of the animals using a scalpel. Ninety-six animals were used divided into the following groups: control (C), microcurrent (MC); topical treatment with Arnica montana gel (ARN); the ARN + microcurrent (ARN + MC). Treatments were administered daily, and injured tissue samples were collected and processed on Days 2, 6 and 10 for dermis analyses. Myeloperoxidase levels were greater in control than in treatment groups on Days 2 and 6. F4/80 expression was similar among all treatment groups and greater than that in control on Day 2. On Day 6, the expression of vascular endothelial growth factor was higher in the MC group than that in other groups, whereas transforming growth factor-β expression increased in the MC and ARN + MC groups on Day 10. The expression of matrix metalloproteinase-2 was higher in the ARN + MC group when compared with other groups on Day 10. Expression levels of collagen I were increased in the ARN and ARN + MC groups when compared with control and MC groups on Day 6, while expression of collagen III was enhanced in MC, ARN, and ARN + MC groups when compared with the control. The protocol combining microcurrent with topical application of ARN reduces the inflammatory process, increases myofibroblasts proliferation and decreases the presence of macrophages in the dermis during skin repair in rats.

Effect of Haematological Parameters in the Development of Urethrocutaneous Fistula After Hypospadias Surgery

Investigation of the relationship between urethrocutaneous fistula (UCF) development and haematological parameters after hypospadias surgery was aimed for in this study. Patients who underwent tubularized incised plate urethroplasty between January 2015 and June 2021 with the diagnosis of distal hypospadias were included in the study. We divided the participants into two groups based on UCF development. We compared haematological parameters, including neutrophil, lymphocyte, and platelet counts; neutrophil-lymphocyte ratio (NLR); platelet-lymphocyte ratio (PLR); and systemic immune inflammation index (SII) values between the two groups. A total of 78 patients were included in the study. Of the patients, 11 developed UCF. The mean age of the patients was 74.9 ± 42.8 months. Catheter diameter, operation time, neutrophil counts, NLR, and SII values were similar between those with and without UCF (p > 0.05). However, the UCF group had significantly higher lymphocyte and platelet counts than those without UCF (p < 0.05). Moreover, the PLR value was significantly lower in the UCF group (p < 0.05). Patients who developed UCF post hypospadias surgery had a significant association with altered blood cell counts, including increased lymphocytes and decreased PLR rate. The PLR can be used as a biological marker for UCF development.

AI-Assisted Assessment of Wound Tissue with Automatic Color and Measurement Calibration on Images Taken with a Smartphone

Wound assessment is essential for evaluating wound healing. One cornerstone of wound care practice is the use of clinical guidelines that mandate regular documentation, including wound size and wound tissue composition, to determine the rate of wound healing. The traditional method requires wound care professionals to manually measure the wound area and tissue composition, which is time-consuming, costly, and difficult to reproduce. In this work, we propose an approach for automatic wound assessment that incorporates automatic color and measurement calibration and artificial intelligence algorithms. Our approach enables the comparison of images taken at different times, even if they were taken under different lighting conditions, distances, lenses, and camera sensors. We designed a calibration chart and developed automatic algorithms for color and measurement calibration. The wound area and wound composition on the images were annotated by three physicians with more than ten years of experience. Deep learning models were then developed to mimic what the physicians did on the images. We examined two network variants, U-Net with EfficientNet and U-Net with MobileNetV2, on wound images with a size of 1024 × 1024 pixels. Our best-performing algorithm achieved a mean intersection over union (IoU) of 0.6964, 0.3957, 0.6421, and 0.1552 for segmenting a wound area, epithelialization area, granulation tissue, and necrotic tissue, respectively. Our approach was able to accurately segment the wound area and granulation tissue but was inconsistent with respect to the epithelialization area and necrotic tissue. The calibration chart, which helps calibrate colors and scales, improved the performance of the algorithm. The approach could provide a thorough assessment of the wound, which could help clinicians tailor treatment to the patient's condition.

Mapping intellectual structure and research hotspots in the field of fibroblast-associated DFUs: a bibliometric analysis

Background

Diabetic foot ulcers (DFUs) are one of the most popular and severe complications of diabetes. The persistent non-healing of DFUs may eventually contribute to severe complications such as amputation, which presents patients with significant physical and psychological challenges. Fibroblasts are critical cells in wound healing and perform essential roles in all phases of wound healing. In diabetic foot patients, the disruption of fibroblast function exacerbates the non-healing of the wound. This study aimed to summarize the hotspots and evaluate the global research trends on fibroblast-related DFUs through bibliometric analysis.

Methods

Scientific publications on the study of fibroblast-related DFUs from January 1, 2000 to April 27, 2022 were retrieved from the Web of Science Core Collection (WoSCC). Biblioshiny software was primarily performed for the visual analysis of the literature, CiteSpace software and VOSviewer software were used to validate the results.

Results

A total of 479 articles on fibroblast-related DFUs were retrieved. The most published countries, institutions, journals, and authors in this field were the USA, The Chinese University of Hong Kong, Wound Repair and Regeneration, and Seung-Kyu Han. In addition, keyword co-occurrence networks, historical direct citation networks, thematic map, and the trend topics map summarize the research hotspots and trends in this field.

Conclusion

Current studies indicated that research on fibroblast-related DFUs is attracting increasing concern and have clinical implications. The cellular and molecular mechanisms of the DFU pathophysiological process, the molecular mechanisms and therapeutic targets associated with DFUs angiogenesis, and the measures to promote DFUs wound healing are three worthy research hotspots in this field.

Native and engineered extracellular vesicles for wound healing

Extracellular vesicles (EVs) that act as messengers mediate communication between parent and recipient cells through their contents, including nucleic acids, proteins, and lipids. These endogenous vesicles have emerged as a novel cell-free strategy for the treatment of diseases. EVs can be released by various types of cells with unique biological properties. Recent studies have shown that native EVs are used as therapeutic agents to promote tissue repair by delivering various growth factors and trophic factors including VEGF, EGF, TFN-α, IL-1β, and TGF-β to participate in all physiological processes of wound healing. Furthermore, to improve their specificity, safety, and efficiency for wound healing, the content and surface of EVs can be designed, modified, and engineered. The engineering strategies of EVs are divided into parent cell modification and indirect modification of EVs. The therapeutic potential of current EVs and engineered EVs for wound healing still requires the exploration of their large-scale clinical applications through innovative approaches. Herein, we provide an overview of the current biological knowledge about wound healing and EVs, as well as the application of native EVs in promoting wound healing. We also outline recent advances in engineering EV methodologies to achieve ideal therapeutic potential. Finally, the therapeutic applications of engineered EVs in wound healing are reviewed, and the challenges and prospects for the translation of engineered EVs to clinical applications are discussed.

Platelet-rich plasma: a comparative and economical therapy for wound healing and tissue regeneration

Rise in the incidences of chronic degenerative diseases with aging makes wound care a socio-economic burden and unceasingly necessitates a novel, economical, and efficient wound healing treatment. Platelets have a crucial role in hemostasis and thrombosis by modulating distinct mechanistic phases of wound healing, such as promoting and stabilizing the clot. Platelet-rich plasma (PRP) contains a high concentration of platelets than naïve plasma and has an autologous origin with no immunogenic adverse reactions. As a consequence, PRP has gained significant attention as a therapeutic to augment the healing process. Since the past few decades, a robust volume of research and clinical trials have been performed to exploit extensive role of PRP in wound healing/tissue regeneration. Despite these rigorous studies and their application in diversified medical fields, efficacy of PRP-based therapies is continuously questioned owing to the paucity of large samplesizes, controlled clinical trials, and standard protocols. This review systematically delineates the process of wound healing and involvement of platelets in tissue repair mechanisms. Additionally, emphasis is laid on PRP, its preparation methods, handling, classification,application in wound healing, and PRP as regenerative therapeutics combined with biomaterials and mesenchymal stem cells (MSCs).

Characterization of Polyphenolic Compounds from Bacopa procumbens and Their Effects on Wound-Healing Process

Wounds represent a medical problem that contributes importantly to patient morbidity and to healthcare costs in several pathologies. In Hidalgo, Mexico, the Bacopa procumbens plant has been traditionally used for wound-healing care for several generations; in vitro and in vivo experiments were designed to evaluate the effects of bioactive compounds obtained from a B. procumbens aqueous fraction and to determine the key pathways involved in wound regeneration. Bioactive compounds were characterized by HPLC/QTOF-MS, and proliferation, migration, adhesion, and differentiation studies were conducted on NIH/3T3 fibroblasts. Polyphenolic compounds from Bacopa procumbens (PB) regulated proliferation and cell adhesion; enhanced migration, reducing the artificial scratch area; and modulated cell differentiation. PB compounds were included in a hydrogel for topical administration in a rat excision wound model. Histological, histochemical, and mechanical analyses showed that PB treatment accelerates wound closure in at least 48 h and reduces inflammation, increasing cell proliferation and deposition and organization of collagen at earlier times. These changes resulted in the formation of a scar with better tensile properties. Immunohistochemistry and RT-PCR molecular analyses demonstrated that treatment induces (i) overexpression of transforming growth factor beta (TGF-β) and (ii) the phosphorylation of Smad2/3 and ERK1/2, suggesting the central role of some PB compounds to enhance wound healing, modulating TGF-β activation.

Exercise-induced increase in M2 macrophages accelerates wound healing in young mice

Moderate-intensity exercise performed during wound healing has been reported to decrease inflammatory cytokines and chemokines and accelerate wound healing. However, its effect on macrophage phenotype and the mechanism by which exercise accelerates wound healing remain unclear. The purpose of this study was to investigate the effect of exercise on macrophage phenotype during wound healing and to clarify the relationship between angiogenesis and wound healing. 12-week-old male C57BL/6J mice were divided into sedentary (n = 6) and exercise groups (n = 6). The exercise group performed moderate-intensity treadmill running exercise (9.0 m/min, 60 min) for 10 days. Double immunofluorescence analysis was performed using F4/80+ inducible nitric oxide synthase (iNOS)+ for M1 macrophages, F4/80+ transforming growth factor-beta (TGF-β)1+ for M2 macrophages, and CD31+ alpha smooth muscle actin (α-SMA)+ for angiogenesis. The exercise group showed significantly accelerated wound healing compared with the sedentary group. From early wound healing onward, exercise significantly inhibited M1 macrophage infiltration and increased M2 macrophage count. Exercise also significantly increased angiogenesis. Furthermore, the M2 macrophage phenotype was significantly correlated with angiogenesis in the exercise group, indicating that M2 macrophages and angiogenesis are related to accelerated wound healing. These findings suggest that moderate-intensity exercise increases TGF-β1 derived from M2 macrophages, which may be associated with enhanced angiogenesis and wound healing in young mice.

Role of Exosomes in Pharyngucutaneous Fistula After Total Laryngectomy

Pharyngocutaneous fistula is the most common complication after total laryngectomy and is difficult to heal. Although conservative treatment and surgical repair are effective, they often take longer and additional trips to the operating room, which undoubtedly increases the financial burden on patients. Especially in combination with diseases such as diabetes and hypertension, which affect the efficacy of surgery. Adding growth factors into the repair material can promote fibroblast proliferation, angiogenesis, and accelerate wound healing. A substantial number of studies have shown that a type of nanoscale extracellular vesicle, called exosomes, facilitates organization repair by promoting blood vessel production, protein polysaccharides, and collagen deposition, thereby representing a new type of cellular therapy. At present, there is little research on the application of exosomes in pharyngocutaneous fistula regeneration after total laryngectomy. In this review, we summarize the biological characteristics of exosomes and their application in biomedical science, and highlight their application prospects in pharyngocutaneous fistula regeneration after total laryngectomy.

Research Progress on Therapeutic Effect and Mechanism of Propolis on Wound Healing

Propolis is a kind of reduct collected by bees from various plant sources. Because propolis is a mixture, it has a variety of biological activities, excellent anti-inflammatory and bactericidal effects. Especially in the treatment of infectious wounds, acute wounds, burns, and scalds and promoting wound healing, more and more scientists began to apply it to the research field of wound healing. The standard preparation of propolis combined with other compound components has a safer and less toxic effect in the treatment of trauma. In order to more effectively use propolis products in wound treatment. This paper reviews the effect and treatment mechanism of propolis on different types of wound healing, as well as the synergistic effect of propolis and other compounds, in order to provide ideas for the further exploration of the biological activity and pharmacological function of propolis in the future, as well as its in-depth development in the field of wound healing. It will also provide a theoretical reference for the further development and utilization of propolis.

Post-acne symptom complex. Approaches to therapy

Postacne-persistent skin changes that appear as a result of long-term acne, inadequate therapy and manipulations performed in the management of this group of patients. The post-acne symptom complex is stable skin changes that appear as a result of long-term acne inadequate therapy and manipulations performed during the management of this group of patients. The pathogenetic mechanisms underlying the launch of acne currently look as follows: androgens cause hyperseborrhea, sebum lipids activate innate immunity; pathological keratinization due to the production of IL-1 inflammatory mediator and androgen hyperproduction; Cutibacterium acnes activate innate immune responses through toll-like receptors and metalloproteinases, stimulate the production of antimicrobial peptides and sebum production. The subsequent rupture of the follicles activates the wound healing process. Depending on the genetically determined features of the course of the inflammatory process, various individual postacne changes of the skin will prevail in different patients. The article highlights the main factors influencing the formation of post-acne, pathogenetic mechanisms underlying the formation of these changes, systematizes modern data on the classification, morphological and pathohistological characteristics of scars. Quantitative and qualitative scales of assessment of post-acne scars for determining the severity of the pathological process are presented, differentiated approaches to modern methods of therapy are discussed in detail, including the advantages and disadvantages of the most common methods of treating patients based on the principles of evidence-based medicine using a number of personalized methods.

ORF8 protein of SARS‐CoV‐2 reduces male fertility in mice

As one of the most rapidly evolving proteins of the genus Betacoronavirus, open reading frames (ORF8's) function and potential pathological consequence in vivo are still obscure. In this study, we show that the secretion of ORF8 is dependent on its N‐terminal signal peptide sequence and can be inhibited by reactive oxygen species scavenger and endoplasmic reticulum‐Golgi transportation inhibitor in cultured cells. To trace the effect of its possible in vivo secretion, we examined the plasma samples of coronavirus disease 2019 (COVID‐19) convalescent patients and found that the patients aged from 40 to 60 had higher antibody titers than those under 40. To explore ORF8's in vivo function, we administered the mice with ORF8 via tail‐vein injection to simulate the circulating ORF8 in the patient. Although no apparent difference in body weight, food intake, and vitality was detected between vehicle‐ and ORF8‐treated mice, the latter displayed morphological abnormalities of testes and epididymides, as indicated by the loss of the central ductal lumen accompanied by a decreased fertility in 5‐week‐old male mice. Furthermore, the analysis of gene expression in the testes between vehicle‐ and ORF8‐treated mice identified a decreased expression of Col1a1, the loss of which is known to be associated with mice's infertility. Although whether our observation in mice could be translated to humans remains unclear, our study provides a potential mouse model that can be used to investigate the impact of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection on the human reproductive system.

ELECTROSPUN SODIUM ALGINATE/POLY(ETHYLENE OXIDE) NANOFIBERS FOR WOUND HEALING APPLICATIONS: CHALLENGES AND FUTURE DIRECTIONS

Alginate is an interesting natural biopolymer to be considered for biomedical applications due to its advantages and good biological properties. These biological properties make electrospun alginate nanofibers suitable for various uses in the biomedical field, such as wound healing dressings, drug delivery systems, or both. Unfortunately, the fabrication of alginate nanofibers by electrospinning is very challenging because of the high viscosity of the solution, high surface tension and rigidity in water due to hydrogen bonding, and also their diaxial linkages. This review presents an overview of the factors affecting the electrospinning process of sodium alginate/poly(ethylene oxide) (SA/PEO), the application of SA/PEO in drug delivery systems for wound healing applications, and the degradation and swelling properties of SA/PEO. The challenges and future directions of SA/PEO in the medical field are also discussed.

A Systematic Review of the Effect of Centella asiatica on Wound Healing

BACKGROUND

Under metabolic stress conditions, there is a higher demand for nutrients which needs to be met. This is to reduce the risk of delay in wound healing which could lead to chronic wound.

AIM

This is a systematic review of the effect of Centella asiatica on wound healing. C. asiatica is a traditional medicinal plant used due to its antimicrobial, antioxidant, anti-inflammatory, neuroprotective, and wound healing properties.

METHODS

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed for the systematic review and four electronic databases were used.

RESULTS

Four clinical trials met the inclusion criteria. The following distinct areas were identified under C. asiatica: wound contraction and granulation; healing/bleeding time and re-epithelialization; VAS (visual analogue scale) scores; skin erythema and wound appearance.

CONCLUSIONS

C. asiatica might enhance wound healing resulting from improved angiogenesis. This might occur due to its stimulating effect on collagen I, Fibroblast Growth Factor (FGF) and Vascular Endothelial Growth Factor (VEGF) production. Besides, C. asiatica has shown an anti-inflammatory effect observed by the reduction in Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and Tumour Necrosis Factor α (TNFα), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), and lipoxygenase (LOX) activity. Delivery systems such as nanoencapsulation could be used to increase C. asiatica bioavailability. Nevertheless, more studies are needed in order to perform a meta-analysis and ascertain the effects of C. asiatica on wound healing and its different parameters.

Evaluation of the Performance of a ZnO-Nanoparticle-Coated Hydrocolloid Patch in Wound Healing

Hydrocolloid dressings are an important method for accelerating wound healing. A combination of a hydrocolloid and nanoparticles (NPs), such as gold (Au), improves the wound healing rate, but Au-NPs are expensive and unable to block ultraviolet (UV) light. Herein, we combined zinc oxide nanoparticles (ZnO-NPs) with hydrocolloids for a less expensive and more effective UV-blocking treatment of wounds. Using Sprague–Dawley rat models, we showed that, during 10-day treatment, a hydrocolloid patch covered with ZnO-NPs (ZnO-NPs-HC) macroscopically and microscopically stimulated the wound healing rate and improved wound healing in the inflammation phase as shown by reducing of pro-inflammatory cytokines (CD68, IL-8, TNF-α, MCP-1, IL-6, IL-1β, and M1) up to 50%. The results from the in vitro models (RAW264.7 cells) also supported these in vivo results: ZnO-NPs-HCs improved wound healing in the inflammation phase by expressing a similar level of pro-inflammatory mediators (TNF-α and IL-6) as the negative control group. ZnO-NPs-HCs also encouraged the proliferation phase of the healing process, which was displayed by increasing expression of fibroblast biomarkers (α-SMA, TGF-β3, vimentin, collagen, and M2) up to 60%. This study provides a comprehensive analysis of wound healing by measuring the biomarkers in each phase and suggests a cheaper method for wound dressing.

Preoperative neutrophil-to-lymphocyte ratio predicts healing time for postoperative pancreatic fistula after distal pancreatectomy

PURPOSE

Postoperative pancreatic fistula is a serious complication of distal pancreatectomy. Although many studies have described the incidence and risk factors associated with postoperative pancreatic fistula (POPF), few have focused on the healing time. This study investigated the healing time and potential factors associated with the healing time of POPF after distal pancreatectomy (DP).

METHODS

Among 114 patients that underwent DP in our hospital from January 2010 to December 2020, we included 88 that developed POPF. The healing time for a postoperative pancreatic fistula was defined as the interval between the completion of DP and the removal of all drains related to the treatment for POPF. Based on the definition, three cases who required additional treatment after removal of all drains were excluded from this study. Clinical factors associated with the fistula healing times were investigated in the 85 patients.

RESULTS

The average POPF healing time was 11 ± 10 days (median: 6 days, range: 3-57). We found that the neutrophil-to-lymphocyte ratio, a marker of inflammatory and nutritional status, was the only factor independently associated with the POPF healing time; the mean healing time was significantly shorter in patients with neutrophil-to-lymphocyte ratio ≤2.1 (8 ± 6 days) than in those with neutrophil-to-lymphocyte ratio >2.1 (13 ± 12 days; P = .0139).

CONCLUSION

We demonstrated that the neutrophil-to-lymphocyte ratio could independently predict the POPF healing time after DP. These findings suggested that improving the neutrophil-to-lymphocyte ratio might shorten the healing times for POPF after DP.

Safety and Ease of Sheath Insertion During Endovascular Treatment Via the Common Femoral Artery After Endarterectomy With Autologous Repair: A Retrospective Cohort Study

Background Endovascular treatment (EVT) using the common femoral artery (CFA) for access after endarterectomy (EA) may result in sheath insertion difficulties because of subcutaneous scar tissue, as well as difficulties with hemostasis. We evaluated the safety of CFA access and the ease of sheath insertion over time after EA. Method We included 19 patients (21 limbs, 40 cases) in whom the CFA was used after EA with autologous repair as an access route in EVT for peripheral arterial disease in our institution from January 2013 to December 2020. Nine limbs underwent simple closure repair and 12 underwent autologous patch repair. Difficult sheath insertions were defined as those in which additional devices (stiff guidewire or a smaller diameter sheath for dilation) were used for scheduled sheath insertion. The inability to insert a sheath with the scheduled diameter was defined as a failed sheath insertion. We evaluated the EVT timing after EA for difficult sheath insertions, and whether the CFA was repaired with simple closure or autologous patch repair during EA surgery. Results There were 10 (25%) difficult sheath insertions, with one (2.5%) failure. The rate of difficult sheath insertions peaked from 6 months to 1 year after EA and gradually decreased (47% from 6 months to 3 years, 14% thereafter). There were more statistically significant difficult sheath insertions with simple closure repair (50%) than with autologous patch repair (12%) (P = 0.018). Hemostasis devices were used in 90% of EVT cases. The median maximum sheath diameter was 6 Fr (mean = 5.8 Fr). None of the cases required surgical procedures to achieve hemostasis after EVT. Conclusion EVT may be performed safely using the CFA after EA. The difficulty of sheath insertion may differ depending on the EVT timing after EA; it was more difficult with simple closure than with autologous patch repair, possibly related to scar formation.

Local Application of Transcutaneous Carbon Dioxide Paste Decreases Inflammation and Accelerates Wound Healing

INTRODUCTION

 Delayed wound healing after surgery lowers the long-term quality of a patient's life and leads to discomfort and pain. However, treatments for wound healing are often difficult and have not yet been fully established. In this study, we investigated the effect of a special paste that can be administered transdermally and holds a non-gaseous carbon dioxide (CO₂) source in its carrier, which can be applied to the head and neck region for wound healing in a rat skin defect model.

METHODS

Forty-eight Sprague Dawley rats were randomized into control and CO₂ groups. We punched a 6.2-mm wound on the back of each rat. The control rats were left untreated, whereas rats in the CO₂ group were treated with the CO₂ paste every day after surgery. We evaluated wound healing 3, 7, 14, and 21 days after wounding by analyzing the diameter of the wound, gene expression of inflammatory markers vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β, hypoxia-inducible factor (HIF)-1α, interleukin (IL)-1β, and IL-6 using quantitative real-time polymerase chain reaction, hematoxylin and eosin, and immunohistochemical staining patterns.

RESULTS

Rats in the CO₂ group showed accelerated wound healing compared to those in the control group. Furthermore, VEGF and TGF-β were overexpressed, whereas HIF-1α, IL-1β, and IL-6 were downregulated in the rats treated with CO₂. Immunohistochemical analysis also revealed similar patterns of expression.

CONCLUSION

Taken together, the CO₂ paste promoted wound healing by regulating the hypoxic environment, reducing inflammation, and accelerating angiogenesis.

Enhancing wound healing dressing development through interdisciplinary collaboration

The process of wound healing includes four phases: Hemostasis, inflammation, proliferation, and remodeling. Many wound dressings and technologies have been developed to enhance the body's ability to close wounds and restore the function of damaged tissues. Several advancements in wound healing technology have resulted from innovative experiments by individual scientists or physicians working independently. The interplay between the medical and scientific research fields is vital to translating new discoveries in the lab to treatments at the bedside. Tracing the history of wound dressing development reveals that there is an opportunity for deeper collaboration between multiple disciplines to accelerate the advancement of novel wound healing technologies. In this review, we explore the different types of wound dressings and biomaterials used to treat wounds, and we investigate the role of multidisciplinary collaboration in the development of various wound management technologies to illustrate the benefit of direct collaboration between physicians and scientists.

Harnessing Multifaceted Next-Generation Technologies for Improved Skin Wound Healing

Dysregulation of sequential and synchronized events of skin regeneration often results in the impairment of chronic wounds. Conventional wound dressings fail to trigger the normal healing mechanism owing to the pathophysiological conditions. Tissue engineering approaches that deal with the fabrication of dressings using various biomaterials, growth factors, and stem cells have shown accelerated healing outcomes. However, most of these technologies are associated with difficulties in scalability and cost-effectiveness of the products. In this review, we survey the latest developments in wound healing strategies that have recently emerged through the multidisciplinary approaches of bioengineering, nanotechnology, 3D bioprinting, and similar cutting-edge technologies to overcome the limitations of conventional therapies. We also focus on the potential of wearable technology that supports complete monitoring of the changes occurring in the wound microenvironment. In addition, we review the role of advanced devices that can precisely enable the delivery of nanotherapeutics, oligonucleotides, and external stimuli in a controlled manner. These technological advancements offer the opportunity to actively influence the regeneration process to benefit the treatment regime further. Finally, the clinical relevance, trajectory, and prospects of this field have been discussed in brief that highlights their potential in providing a beneficial wound care solution at an affordable cost.

Engineering Bioactive Scaffolds for Skin Regeneration

Large skin wounds pose a major clinical challenge. Scarcity of donor site and postsurgical scarring contribute to the incomplete or partial loss of function and aesthetic concerns in skin wound patients. Currently, a wide variety of skin grafts are being applied in clinical settings. Scaffolds are used to overcome the issues related to the misaligned architecture of the repaired skin tissues. The current review summarizes the contribution of biomaterials to wound healing and skin regeneration and addresses the existing limitations in skin grafting. Then, the clinically approved biologic and synthetic skin substitutes are extensively reviewed. Next, the techniques for modification of skin grafts aiming for enhanced tissue regeneration are outlined, and a summary of different growth factor delivery systems using biomaterials is presented. Considering the significant progress in biomaterial science and manufacturing technologies, the idea of biomaterial-based skin grafts with the ability for scarless wound healing and reconstructing full skin organ is more achievable than ever.

Oral wound healing models and emerging regenerative therapies

Following injury, the oral mucosa undergoes complex sequences of biological healing processes to restore homeostasis. While general similarities exist, there are marked differences in the genomics and kinetics of wound healing between the oral cavity and cutaneous epithelium. The lack of successful therapy for oral mucosal wounds has influenced clinicians to explore alternative treatments and potential autotherapies to enhance intraoral healing. The present in-depth review discusses current gold standards for oral mucosal wound healing and compares endogenous factors that dictate the quality of tissue remodeling. We conducted a review of the literature on in vivo oral wound healing models and emerging regenerative therapies published during the past twenty years. Studies were evaluated by injury models, therapy interventions, and outcome measures. The success of therapeutic approaches was assessed, and research outcomes were compared based on current hallmarks of oral wound healing. By leveraging therapeutic advancements, particularly within in cell-based biomaterials and immunoregulation, there is great potential for translational therapy in oral tissue regeneration.

New Insights on the Effects of Dietary Omega-3 Fatty Acids on Impaired Skin Healing in Diabetes and Chronic Venous Leg Ulcers

Long-chain Omega-3 polyunsaturated fatty acids (Omega-3 PUFAs) are widely recognized as powerful negative regulators of acute inflammation. However, the precise role exerted by these dietary compounds during the healing process is still largely unknown, and there is increasing interest in understanding their specific effects on the implicated cells/molecular factors. Particular attention is being focused also on their potential clinical application in chronic pathologies characterized by delayed and impaired healing, such as diabetes and vascular diseases in lower limbs. On these bases, we firstly summarized the current knowledge on wound healing (WH) in skin, both in normal conditions and in the setting of these two pathologies, with particular attention to the cellular and molecular mechanisms involved. Then, we critically reviewed the outcomes of recent research papers investigating the activity exerted by Omega-3 PUFAs and their bioactive metabolites in the regulation of WH in patients with diabetes or venous insufficiency and showing chronic recalcitrant ulcers. We especially focused on recent studies investigating the mechanisms through which these compounds may act. Considerations on the optimal dietary doses are also reported, and, finally, possible future perspectives in this area are suggested.

Effectiveness of a combination therapy using non-ablative fractional laser and intralesional triamcinolone injection for thyroidectomy scar treatment: a prospective, randomized, blinded pilot study

BACKGROUND

The occurrence of thyroid cancer has increased dramatically, and postoperative scars are placed at easily visible locations. Many patients show stronger desire for scar prevention. So far, numerous approaches have been discussed for the treatment of scars; this study is conducted to verify whether the early application of combined therapy contributes to minimal scar formation.

METHODS

Between March 2019 and December 2019, total of 64 patients with thyroidectomy scars of a size greater than 4.5 cm located on the anterior neck were enrolled in this prospective pilot study. Subjective and objective evaluation were carried out using the Patient and Observer Scar Assessment Scale (POSAS) at one, two, and six months after operation. Results were compared between a treatment group and a non-treatment group.

RESULTS

In PSAS score, the mean values of pain, itching sensation, pliability, thickness, and relief were significantly higher in the laser and steroid treatment group (p = 0.009, p = 0.000, p = 0.013, p = 0.002, and p = 0.007). The value of color of the scars showed no significant differences (p = 0.504). In OSAS score, parameter of thickness, relief, and surface area score was significantly higher score in the combination group (p = 0.029, 0.035, and 0.020), while vascularity, pigmentation, and pliability were not significantly different between two groups (p = 0.548, p = 0.983, and p = 0.128).

CONCLUSION

This study demonstrates that early combination therapy contributes to scar improvement to a meaningful extent based on POSAS. We believe that the combined therapy has a synergy effect on scar management, which improves the patients' quality of life in relation to their postoperative scars.

Anti-inflammatory and antioxidant properties of Alternanthera brasiliana improve cutaneous wound healing in rats

Alternanthera brasiliana (L.) Kuntze is recognized for its healing properties; however, its therapeutic effects remain unclear. Therefore, our study aimed to elucidate the wound healing activities of A. brasiliana using in vitro and in vivo assays. In vitro assays were used to evaluate the antibacterial, anti-inflammatory, and antioxidant effects of A. brasiliana extract. For the in vivo study, two dorsal excisions were established in Wistar rats using a punch (1.5 cm in diameter), which were topically treated daily with 2% carbopol gel (Ctrl group) or 20% hydroalcoholic plant extract with 2% carbopol gel (A. brasiliana-Ab group). After the 2nd, 7th, 14th, and 21st days, inflammation, oxidative damage, antioxidants, angiogenesis, tissue formation, and re-epithelialization were evaluated. In vitro, Ab reduced nitric oxide, anion superoxide, and pro-inflammatory cytokine production. In vivo, Ab presented lower levels of inflammatory infiltrate, although increased levels of IL-1β and TGF-β1 were observed. The plant extract controlled oxidative damage by antioxidants, which favored angiogenesis, collagenesis, and wound re-epithelialization. Thus, the topical application of the hydroalcoholic extract of 20% A. brasiliana was distinguished by its important anti-inflammatory and antioxidant activities both in vivo and in vitro. The plant extract also stimulated angiogenesis and tissue formation, accelerating total re-epithelization, which is promising for wound healing.

Low Ozone Concentrations Differentially Affect the Structural and Functional Features of Non-Activated and Activated Fibroblasts In Vitro

Oxygen-ozone (O2-O3) therapy is increasingly applied as a complementary/adjuvant treatment for several diseases; however, the biological mechanisms accounting for the efficacy of low O3 concentrations need further investigations to understand the possibly multiple effects on the different cell types. In this work, we focused our attention on fibroblasts as ubiquitous connective cells playing roles in the body architecture, in the homeostasis of tissue-resident cells, and in many physiological and pathological processes. Using an established human fibroblast cell line as an in vitro model, we adopted a multimodal approach to explore a panel of cell structural and functional features, combining light and electron microscopy, Western blot analysis, real-time quantitative polymerase chain reaction, and multiplex assays for cytokines. The administration of O2-O3 gas mixtures induced multiple effects on fibroblasts, depending on their activation state: in non-activated fibroblasts, O3 stimulated proliferation, formation of cell surface protrusions, antioxidant response, and IL-6 and TGF-β1 secretion, while in LPS-activated fibroblasts, O3 stimulated only antioxidant response and cytokines secretion. Therefore, the low O3 concentrations used in this study induced activation-like responses in non-activated fibroblasts, whereas in already activated fibroblasts, the cell protective capability was potentiated.

Platelet HMGB1 in Platelet-Rich Plasma (PRP) promotes tendon wound healing

Platelet-rich plasma (PRP) is a widely used autologous treatment for tendon injuries in clinics. Platelets (PLTs) are a major source of high mobility group box1 (HMGB1) that is gaining attention as a chemoattractant that can recruit stem cells to the wound area to enhance healing of injured tissues; however, the contribution of PLT HMGB1 in wounded tendon healing remains unexplored. This study investigated the effect of PLT HMGB1 within PRP on tendon healing using PLT HMGB1 knockout (KO) and GFP mice. A window defect was created in the patellar tendons of both groups of mice, and wounds were treated with either saline, PRP isolated from PLT HMGB1-KO mice, or PRP isolated from GFP mice. Seven days post-treatment, animals were sacrificed and analyzed by gross inspection, histology, and immunostaining for characteristic signs of tendon healing and repair. Our results showed that in comparison to mice treated with PRP from PLT HMGB1-KO mice, wounds treated with PRP from GFP mice healed faster and exhibited a better organization in tendon structure. Mice treated with PRP from PLT HMGB1-KO mice produced tendon tissue with large premature wound areas and low cell densities. However, wounds of PLT HMGB1-KO mice showed better healing with PRP from HMGB1-KO mice compared to saline treatment. Moreover, wounds treated with PRP from GFP mice had increased extracellular HMGB1, decreased CD68, increased stem cell markers CD146 and CD73, and increased collagen III protein expression levels compared to those treated with PRP from PLT HMGB1-KO mice. Thus, PLT HMGB1 within PRP plays an important role in tendon wound healing by decreasing inflammation, increasing local HMGB1 levels, and recruiting stem cells to the wound area in the tendon. Our findings also suggest that the efficacy of PRP treatment for tendon injuries in clinics may depend on PLT HMGB1 within PRP preparations.

Stability of a one-dimensional morphoelastic model for post-burn contraction

To deal with permanent deformations and residual stresses, we consider a morphoelastic model for the scar formation as the result of wound healing after a skin trauma. Next to the mechanical components such as strain and displacements, the model accounts for biological constituents such as the concentration of signaling molecules, the cellular densities of fibroblasts and myofibroblasts, and the density of collagen. Here we present stability constraints for the one-dimensional counterpart of this morphoelastic model, for both the continuous and (semi-) discrete problem. We show that the truncation error between these eigenvalues associated with the continuous and semi-discrete problem is of order \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\mathcal {O}}}(h^2)$$\end{document}O(h2). Next we perform numerical validation to these constraints and provide a biological interpretation of the (in)stability. For the mechanical part of the model, the results show the components reach equilibria in a (non) monotonic way, depending on the value of the viscosity. The results show that the parameters of the chemical part of the model need to meet the stability constraint, depending on the decay rate of the signaling molecules, to avoid unrealistic results.

Sensitivity and feasibility of a one-dimensional morphoelastic model for post-burn contraction

We consider a one-dimensional morphoelastic model describing post-burn scar contraction. Contraction can lead to a limited range of motion (contracture). Reported prevalence of burn scar contractures are 58.6% at 3-6 weeks and 20.9% at 12 months post-reconstructive surgery after burns. This model describes the displacement of the dermal layer of the skin and the development of the effective Eulerian strain in the tissue. Besides these components, the model also contains components that play a major role in the skin repair after trauma. These components are signaling molecules, fibroblasts, myofibroblasts, and collagen. We perform a sensitivity analysis for many parameters of the model and use the results for a feasibility study. In this study, we test whether the model is suitable for predicting the extent of contraction in different age groups. To this end, we conduct an extensive literature review to find parameter values. From the sensitivity analysis, we conclude that the most sensitive parameters are the equilibrium collagen concentration in the dermal layer, the apoptosis rate of fibroblasts and myofibroblasts, and the secretion rate of signaling molecules. Further, although we can use the model to simulate significant distinct contraction densities in different age groups, our results differ from what is seen in the clinic. This particularly concerns children and elderly patients. In children we see more intense contractures if the burn injury occurs near a joint, because the growth induces extra forces on the tissue. Elderly patients seem to suffer less from contractures, possibly because of excess skin.

Nanocarrier-Mediated Topical Insulin Delivery for Wound Healing

Wound care has been clinically demanding due to inefficacious treatment that represents an economic burden for healthcare systems. In Europe, approximately 7 million people are diagnosed with untreated wounds, leading to a cost between 6.000€ and 10.000€ per patient/year. In the United States of America, 1.5 million people over 65 years old suffer from chronic wounds. A promising therapeutic strategy is the use of exogenous growth factors because they are decreased at the wound site, limiting the recovery of the skin. Insulin is one of the cheapest growth factors in the market able to accelerate the re-epithelialization and stimulate angiogenesis and cell migration. However, the effectiveness of topical insulin in wound healing is hampered by the proteases in the wound bed. The encapsulation into nanoparticles improves its stability in the wound, providing adhesion to the mucosal surface and allowing its sustained release. The aim of this review is to perform a standing point about a promising strategy to treat different types of wounds by the topical delivery of insulin-loaded nanocarriers.

The Effect of Amino Acids on Wound Healing: A Systematic Review and Meta-Analysis on Arginine and Glutamine

Under stress conditions, the metabolic demand for nutrients increases, which, if not met, may slow down or indeed stop the wound from healing, thus, becoming chronic wounds. This study aims to perform a systematic review and meta-analysis of the effect of arginine and glutamine supplementation on wound healing. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed for the systematic review and ten electronic databases were used. Five and 39 human studies met the inclusion criteria for arginine and glutamine, respectively. The overall meta-analysis demonstrated a significant effect of arginine supplementation on hydroxyproline content (MD: 4.49, 95% CI: 3.54, 4.45, p < 0.00001). Regarding glutamine supplementation, there was significant effect on nitrogen balance levels (MD: 0.39, 95% CI: 0.21, 0.58, p < 0.0001), IL-6 levels (MD: −5.78, 95% CI: −8.71, −2.86, p = 0.0001), TNFα levels (MD: −8.15, 95% CI: −9.34, −6.96, p < 0.00001), lactulose/mannitol (L/M) ratio (MD: −0.01, 95% CI: −0.02, −0.01, p < 0.00001), patient mortality (OR: 0.48, 95% CI: 0.32, 0.72, p = 0.0004), C-reactive protein (CRP) levels (MD: −1.10, 95% CI: −1.26, −0.93, p < 0.00001) and length of hospital stay (LOS) (MD: −2.65, 95% CI: −3.10, −2.21, p < 0.00001). Regarding T-cell lymphocytes, a slight decrease was observed, although it failed to reach significance (MD: −0.16, 95% CI: −0.33, 0.01, p = 0.07). Conclusion: The wound healing might be enhanced in one or at various stages by nutritional supplementation in the right dose.

The influence of a biofilm-dispersing wound gel on the wound healing process

Topical antimicrobials that reduce the bacterial bioburden within a chronically‐infected wound may have helpful or harmful effects on the healing process. We used murine models of full‐thickness skin wounds to determine the effects of the novel biofilm‐dispersing wound gel (BDWG) and its gel base on the healing of uninfected wounds. The rate of wound closure over 19 days was comparable among the BDWG‐treated (BT) wounds and the controls. Compared with the controls, histology of the BT wounds showed formation of a stable blood clot at day 1, more neovascularisation and reepithelialisation at day 3, and more organised healing at day 7. Fluorescence‐activated cell sorting analysis showed a lower percentage of neutrophils in wounded tissues of the BT group at days 1 and 3, and significantly more M2 macrophages at day 3. Levels of proinflammatory cytokines and chemokines were increased over the uninjured baseline within the wounds of all treatment groups but the levels were significantly lower in the BT group at day 1, modulating the inflammatory response. Our results suggest that BDWG does not interfere with the wound healing process and may enhance it by lowering inflammation and allowing transition to the proliferative stage of wound healing by day 3.

Persistent proliferation of keratinocytes and prolonged expression of pronociceptive inflammatory mediators might be associated with the postoperative pain in KK mice

Epidermal keratinocytes play a vital role in restoration of the intact skin barrier during wound healing. The negative effect of hyperglycemia may prolong the wound healing process. Epidermal keratinocytes have been demonstrated to modulate and directly initiate nociceptive responses in rat models of fractures and chemotherapy-induced neuropathic pain. However, it is unclear whether epidermal keratinocytes are involved in the development and maintenance of incisional pain in nondiabetic or diabetic animals. In the current study, using behavioral tests and immunohistochemistry, we investigated the differential keratinocytes proliferation and expression of pronociceptive inflammatory mediators in keratinocytes in C57BL/6J mice and diabetic KK mice. Our data showed that plantar incision induced postoperative pain hypersensitivity in both C57BL/6J mice and KK mice, while the duration of postoperative pain hypersensitivity in KK mice was longer than that in C57BL/6J mice. Moreover, plantar incision induced the keratinocytes proliferation and expression of IL-1β and TNF-α in keratinocytes in both C57BL/6J mice and KK mice. Interestingly, compared to C57BL/6J mice, the slower and more persistent proliferation of keratinocytes and expression of IL-1β and TNF-α in keratinocytes were observed in KK mice. Together, our study suggested that plantar incision may induce the differential keratinocytes proliferation and expression of IL-1β and TNF-α in kertinocytes in diabetic and nondiabetic animals, which might be associated with the development and maintenance differences in diabetic and nondiabetic postoperative pain.

Systems biology approach highlights mechanistic differences between Crohn's disease and ulcerative colitis

The molecular mechanisms of IBD have been the subject of intensive exploration. We, therefore, assembled the available information into a suite of causal biological network models, which offer comprehensive visualization of the processes underlying IBD. Scientific text was curated by using Biological Expression Language (BEL) and compiled with OpenBEL 3.0.0. Network properties were analysed by Cytoscape. Network perturbation amplitudes were computed to score the network models with transcriptomic data from public data repositories. The IBD network model suite consists of three independent models that represent signalling pathways that contribute to IBD. In the “intestinal permeability” model, programmed cell death factors were downregulated in CD and upregulated in UC. In the “inflammation” model, PPARG, IL6, and IFN-associated pathways were prominent regulatory factors in both diseases. In the “wound healing” model, factors promoting wound healing were upregulated in CD and downregulated in UC. Scoring of publicly available transcriptomic datasets onto these network models demonstrated that the IBD models capture the perturbation in each dataset accurately. The IBD network model suite can provide better mechanistic insights of the transcriptional changes in IBD and constitutes a valuable tool in personalized medicine to further understand individual drug responses in IBD.

Nutritional Support for Bariatric Surgery Patients: The Skin beyond the Fat

Body contouring surgery after the massive weight loss due to bariatric surgery deals with different kinds of complications. The aim of this review is to analyze the role that some nutrients may play in tissue healing after surgery, thus helping plastic surgeons to improve the aesthetic and health outcomes in massive weight loss patients under a multidisciplinary approach. As a matter of fact, preoperative nutritional deficiencies have been shown for vitamins and minerals in a large percentage of post-bariatric patients. Preoperative deficiencies mainly concern iron, zinc, selenium, and vitamins (both fat-soluble and water-soluble), but also total protein. During the postoperative period, these problems may increase because of the patients' very low intake of vitamins and minerals after bariatric surgery (below 50% of the recommended dietary allowance) and the patients' low compliance with the suggested multivitamin supplementation (approximately 60%). In the postoperative period, more attention should be given to nutritional aspects in regard to the length of absorptive area and the percentage of weight loss.

Healing of colonic anastomosis in rats under obstructive ileus conditions

BACKGROUND

The anastomosis leak in colon resections is a crucial post-operative complication with significant morbidity and mortality.  Methods: Forty (40) Wistar rats were allocated in two groups. In SHAM group only anastomosis was performed. In ILEUS group anastomosis was performed following one day of ileus. Animals in both groups were subdivided in two groups according to the day they were sacrificed, 4th or 8th post-operative day. A number of variables between the groups were estimated.

RESULTS

Body weight loss was higher following obstructive ileus on both days. Adhesion score in 4th and 8th post-operative day was higher in ILEUS1, ILEUS2 groups compared to SHAM1, SHAM2 groups respectively (p<0.001 for both). Neovascularization decreased following obstructive ileus compared to control on the 4th day (ILEUS1 vs. SHAM1, p=0.038). Bursting pressure was lower in ILEUS2 group than SHAM2 group (p<0.001). The number of fibroblasts decreased following obstructive ileus compared to control on the 4th and 8th day (ILEUS1 vs. SHAM1, p=0.001, ILEUS2 vs SHAM2, p=0.016). Hydroxyproline concentration was decreased in ILEUS2 group compared to SHAM2 group (p<0.001).

CONCLUSIONS

The balance of collagenolysis and collagenogenesis plays a decisive role in the healing of anastomoses following bowel obstruction. Under those circumstances, anastomosis' bursting pressure is reduced owning to decreased neovascularization, reduced fibroblast presence and lower hydroxyproline concertation. In our study, local inflammation, neocollagen concentration and collagenase activity were not associated with this adverse effect. However, further research should delineate the mechanisms of healing of colonic anastomoses and identify those factors that can improve our outcomes.

Effect of bovine bone collagen oligopeptides on wound healing in mice

Impaired wound healing often brings a set of problems in clinical practice. This study aimed to observe the wound healing potential of bovine bone collagen oligopeptides (BCOP) in mice. After an operation, mice in BCOP-treated groups were given intragastric administration of BCOP, while others were administered vehicle. Mice were sacrificed at different points. The wound healing condition and the tensile strength were observed, serum biochemical indexes and mRNA expression of level of related genes were measured. Compared with the normal control group, albumin (ALB), prealbumin (PA), transferrin (TRF), hydroxyproline (Hyp) levels and tension strength in the BCOP-treated groups increased significantly (p < 0.05). A pathological report showed that neutrophil granulocyte in the BCOP-treated groups decreased, while blood capillary and fibroblasts increased. The levels of serum inflammation indexes like interleukin (IL)-8, tumor necrosis factor (TNF)-α, chemokine (C-C motif) ligand 2 (CCL2) and C-reactive protein (CRP) significantly decreased in full-thickness incision model, whereas increased in full-thickness excision model (p < 0.05). Furthermore, IL-10, stromal cell-derived factor-1 alpha (SDF-1α) levels and the mRNA expression of vascular endothelial growth factor (VEGF) significantly increased in both models (p < 0.05). These results suggested that oral administration of BCOP could promote wound healing in mice.

Optical Coherence Tomography Angiography Monitors Cutaneous Wound Healing under Angiogenesis-Promoting Treatment in Diabetic and Non-Diabetic Mice

During wound healing, the rapid re-establishment of a functional microcirculation in the wounded tissue is of utmost importance. We applied optical coherence tomography (OCT) angiography to evaluate vascular remodeling in an excisional wound model in the pinnae of C57BL/6 and db/db mice receiving different proangiogenic topical treatments. Analysis of the high-resolution OCT angiograms, including the four quantitative parameters vessel density, vessel length, number of bifurcations, and vessel tortuosity, revealed changes of the microvasculature and allowed identification of the overlapping wound healing phases hemostasis, inflammation, proliferation, and remodeling. Angiograms acquired in the inflammatory phase in the first days showed a dilation of vessels and recruitment of pre-existing capillaries. In the proliferative phase, angiogenesis with the sprouting of new capillaries into the wound tissue led to an increase of the OCT angiography parameters vessel density, normalized vessel length, number of bifurcations, and vessel tortuosity by 28–47%, 39–52%, 33–48%, and 3–8% versus baseline, respectively. After the peak observed on study days four to seven, the parameters slowly decreased but remained still elevated 18 days after wounding, indicating a continuing remodeling phase. Our study suggests that OCT angiography has the potential to serve as a valuable preclinical research tool in studies investigating impaired vascular remodeling during wound healing and potential new treatment strategies.

Development of Cephradine-Loaded Gelatin/Polyvinyl Alcohol Electrospun Nanofibers for Effective Diabetic Wound Healing: In-Vitro and In-Vivo Assessments

Diabetic wound infections caused by conventional antibiotic-resistant Staphylococcus aureus strains are fast emerging, leading to life-threatening situations (e.g., high costs, morbidity, and mortality) associated with delayed healing and chronic inflammation. Electrospinning is one of the most widely used techniques for the fabrication of nanofibers (NFs), induced by a high voltage applied to a drug-loaded polymer solution. Particular attention is given to electrospun NFs for pharmaceutical applications (e.g., original drug delivery systems) and tissue regeneration (e.g., as tissue scaffolds). However, there is a paucity of reports related to their application in diabetic wound infections. Therefore, we prepared eco-friendly, biodegradable, low-immunogenic, and biocompatible gelatin (GEL)/polyvinyl alcohol (PVA) electrospun NFs (BNFs), in which we loaded the broad-spectrum antibiotic cephradine (Ceph). The resulting drug-loaded NFs (LNFs) were characterized physically using ultraviolet-visible (UV-Vis) spectrophotometry (for drug loading capacity (LC), drug encapsulation efficiency (EE), and drug release kinetics determination), thermogravimetric analysis (TGA) (for thermostability evaluation), scanning electron microscopy (SEM) (for surface morphology analysis), and Fourier-transform infrared spectroscopy (FTIR) (for functional group identification). LNFs were further characterized biologically by in-vitro assessment of their potency against S. aureus clinical strains (N = 16) using the Kirby–Bauer test and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, by ex-vivo assessment to evaluate their cytotoxicity against primary human epidermal keratinocytes using MTT assay, and by in-vivo assessment to estimate their diabetic chronic wound-healing efficiency using NcZ10 diabetic/obese mice (N = 18). Thin and uniform NFs with a smooth surface and standard size (<400 nm) were observed by SEM at the optimized 5:5 (GEL:PVA) volumetric ratio. FTIR analyses confirmed the drug loading into BNFs. Compared to free Ceph, LNFs were significantly more thermostable and exhibited sustained/controlled Ceph release. LNFs also exerted a significantly stronger antibacterial activity both in-vitro and in-vivo. LNFs were significantly safer and more efficient for bacterial clearance-induced faster chronic wound healing. LNF-based therapy could be employed as a valuable dressing material to heal S. aureus-induced chronic wounds in diabetic subjects.

Thrombin generation and activity in multiple sclerosis

The coagulation cascade and immune system are intricately linked, highly regulated and respond cooperatively in response to injury and infection. Increasingly, evidence of hyper-coagulation has been associated with autoimmune disorders, including multiple sclerosis (MS). The pathophysiology of MS includes immune cell activation and recruitment to the central nervous system (CNS) where they degrade myelin sheaths, leaving neuronal axons exposed to damaging inflammatory mediators. Breakdown of the blood-brain barrier (BBB) facilitates the entry of peripheral immune cells. Evidence of thrombin activity has been identified within the CNS of MS patients and studies using animal models of experimental autoimmune encephalomyelitis (EAE), suggest increased thrombin generation and activity may play a role in the pathogenesis of MS as well as inhibit remyelination processes. Thrombin is a serine protease capable of cleaving multiple substrates, including protease activated receptors (PARs), fibrinogen, and protein C. Cleavage of all three of these substrates represent pathways through which thrombin activity may exert immuno-regulatory effects and regulate permeability of the BBB during MS and EAE. In this review, we summarize evidence that thrombin activity directly, through PARs, and indirectly, through fibrin formation and activation of protein C influences neuro-immune responses associated with MS and EAE pathology.