The physiology of wound healing

Enhancing burn wound care with pre-crosslinked 3D-printed patches: Bromelain delivery and aloe vera bioactives integration for improved healing outcomes

Burn wounds remain a major clinical challenge due to the limitations of traditional dressings, which often fail to address the diverse needs of patients and varying wound types. This study aimed to advance burn care by developing a 3D-printed patch incorporating natural bioactive compounds from bromelain and aloe vera. The patch was formulated using pre-crosslinked chitosan and alginate hydrogels to ensure suitability for 3D printing and subsequent use. Rheological analysis revealed weak gel behaviour and shear-thinning properties, ensuring excellent printability. The patches exhibited outstanding swelling behaviour and controlled degradation (30 %), alongside notable antioxidant and anti-inflammatory potential, with a polyphenolic content of 1.43 ± 0.07 mg CAE/g and effective scavenging of DPPH, ABTS, and NO radicals, with IC50 values of 29.51 ± 0.30, 10.31 ± 0.28, and 5.94 ± 0.42 mg/mL, respectively. Bioactive compounds from bromelain were consistently released across various pH levels, supporting their therapeutic efficacy. Cell viability studies confirmed strong support for cell growth, while in vitro scratch tests demonstrated biocompatibility and promotion of wound closure. Histological analysis of ex vivo burn models revealed cellular necrosis and protein denaturation characteristic of burn wounds. Application of the patches significantly improved epidermal morphology and enhanced proliferation markers such as Ki67 and α-SMA, indicative of accelerated wound healing. While further clinical validation is needed, these findings underscore the potential of the 3D-printed patches as an innovative solution for burn wound care, offering improved bioactive delivery and enhanced healing outcomes compared to conventional dressings.

Synthesis of a retro-GFOGER Adamantane-Based Collagen Mimetic Peptide Imbibed in a Hyaluronic Acid Hydrogel for Enhanced Wound Healing

This study reported the synthesis and formulation of an adamantane-based collagen mimetic peptide (CMP) hydrogel containing the integrin-binding motif retro-GFOGER, designed to enable the controlled delivery of CMPs with the ability of direct wound healing for the potential treatment of acute wounds. Initially, two adamantane-functionalized CMPs (peptides NL008 and NL010) were synthesized, characterized, and comparatively screened for their in vitro biocompatibility and bioactivity. In vitro evaluations of scratch closure and biocompatibility were assessed on human-derived keratinocytes. Release and permeation of the peptides were evaluated in vitro and ex vivo. Wound closure rates and histological evaluations were performed on male Sprague-Dawley rats over 3, 7, and 14 days for the NL010-HAgel formulation. Peptide NL010 was found to be the most suitable candidate among the adamantane CMPs. For a comparative study, peptide NL010 and its palmitic acid analogue, NL009, were loaded into a hyaluronic acid (HA) hydrogel and lyophilized. The CMP hydrogels exhibited porosity (<30 μm) and were viscoelastic solids. The physicomechanical properties of the formulations showed optimal characteristics for application as wound dressings in terms of textural profile. Peptide NL008 exhibited lower bioactivity and cell viability compared to NL009 and NL010 across various concentrations and cell lines. Peptide release from NL009-HAgel and NL010-HA gel was 74% and 83%, respectively. Across an ex vivo porcine skin membrane, the CMP-HAgel showed good permeation and was retained in the epidermis and superficial dermis. CMP-HAgel at 0.1% (w/v) showed better HaCaT cell viabilities. In vitro assays demonstrated that the NL010-HA gel achieved scratch closure (99.9%) within 24 h, while the NL009-HAgel showed scratch closure (93.7%) within the same time frame. In vivo, NL010-HAgel improved healing by enhancing epithelialization and granulation tissue deposition (via fibroblast and collagen responses). The findings of this study suggested that the CMP cell-instructive hydrogel is a promising platform with the potential to accelerate wound healing.

The Angiogenic Repertoire of Stem Cell Extracellular Vesicles: Demystifying the Molecular Underpinnings for Wound Healing Applications

Stem cells-derived extracellular vesicles (SC-EVs) have emerged as promising therapeutic agents for wound repair, recapitulating the biological effects of parent cells while mitigating immunogenic and tumorigenic risks. These EVs orchestrate wound healing processes, notably through modulating angiogenesis-a critical event in tissue revascularization and regeneration. This study provides a comprehensive overview of the multifaceted mechanisms underpinning the pro-angiogenic capacity of EVs from various stem cell sources within the wound microenvironment. By elucidating the molecular intricacies governing their angiogenic prowess, we aim to unravel the mechanistic repertoire underlying their remarkable potential to accelerate wound healing. Additionally, methods to enhance the angiogenic effects of SC-EVs, current limitations, and future perspectives are highlighted, emphasizing the significant potential of this rapidly advancing field in revolutionizing wound healing strategies.

Curcumin-Polyethylene Glycol Loaded on Chitosan-Gelatin Nanoparticles Enhances Infected Wound Healing

The aim of the present study was to evaluate effects of curcumin-polyethylene glycol loaded on chitosan-gelatin nanoparticles (C-PEG-CGNPs) on healing of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds in rat as a model study. Forty male Wistar rats were randomized into 5 groups of 8 animals each. In CNTRL group, no infected/no treated wounds were covered with sterile saline 0.9% solution (0.1 mL). In MRSA group, MRSA-infected wounds were only treated with sterile saline 0.9% solution (0.1 mL). In MRSA/CP group, 0.1 mL curcumin nanoparticles (1 mg/mL) was applied topically to treat MRSA-infected wounds. In MRSA/CG group, 0.1 mL CG (1 mg/mL) was applied topically to treat MRSA-infected wounds. In MRSA/CP-CG group, 0.1 mL CP-CG (1 mg/mL) was applied topically to treat MRSA-infected wounds. Microbiological examination; planimetric, biochemical, histological, morphometric studies, angiogenesis, hydroxyproline levels, and reverse transcription polymerase chain reaction for caspase 3, Bcl-2, and p53 showed significant difference between rats in MRSA/CP-CG group in comparison with other groups (P < .05). Accelerated and improved healing in wounds infected with MRSA were observed in animals treated with C-PEG-CGNPs. Via increasing solubility of curcumin in C-PEG-CGNP, this harmless and easily available composition could be considered to be topically applied in infected wounds.

Local Insulin Improves Wound Healing: A Systematic Review and Bayesian Network Meta-Analysis

BACKGROUND

Wounds are a significant health issue, and reliable and safe strategies to promote repair are needed. Clinical trials have demonstrated that local insulin promotes healing in acute and chronic wounds (ie, reductions of 7% to 40% versus placebo). However, the trials' sample sizes have prevented drawing solid conclusions. Furthermore, no analysis has focused on safety concerns (ie, hypoglycemia). Under the hypothesis that local insulin promotes healing through proangiogenic effects and cellular recruitment, the aim of this systematic review and network meta-analysis (NMA) was to assess its safety and relative effectiveness using a Bayesian approach.

METHODS

Medline, CENTRAL, Embase, Scopus, LILACS, and gray literature sources were searched for human studies assessing the local use of insulin versus any comparator since inception to October of 2020. Data on glucose changes and adverse events, wound and treatment characteristics, and healing outcomes were extracted, and an NMA was conducted.

RESULTS

A total of 949 reports were found, of which 23 ( n = 1240 patients) were included in the NMA. The studies evaluated six different therapies, and most comparisons were against placebo. NMA showed -1.8 mg/dL blood glucose level change with insulin and a lack of reported adverse events. Statistically significant clinical outcomes identified include reduction in wound size (-27%), increased healing rate (23 mm/day), reduction in Pressure Ulcer Scale for Healing scores (-2.7), -10 days to attain complete closure, and an odds ratio of 20 for complete wound closure with insulin use. Likewise, significantly increased neoangiogenesis (+30 vessels/mm 2 ) and granulation tissue (+25%) were also found.

CONCLUSION

Local insulin promotes wound healing without significant adverse events.

Exploring the therapeutic potential of recombinant human lysozyme: a review on wound management system with antibacterial

Lysozyme, a natural antibacterial enzyme protein, possesses the ability to dissolve the cell walls of Gram-positive bacteria, demonstrating broad-spectrum antibacterial activity. Despite its significant potential in treating wound infections and promoting wound healing, its widespread clinical application has yet to be realized. Current research is primarily focused on carrier-based delivery systems for lysozyme. In this review, we discuss four delivery systems that can be employed for lysozyme in wound healing treatment, specifically hydrogels, nanofilms, electrospun fibrous membranes, and modified-lysozyme composite systems. These systems not only enhance the stability of lysozyme but also enable its controlled and sustained release at wound sites, potentially overcoming some of the challenges associated with its direct application. Lastly, we delve into the perspectives and challenges related to the use of these delivery systems, hoping to spur further research and innovation in this promising field.

Is my wound infected? A study on the use of hyperspectral imaging to assess wound infection

Introduction

Clinical signs and symptoms (CSS) of infection are a standard part of wound care, yet they can have low specificity and sensitivity, which can further vary due to clinician knowledge, experience, and education. Wound photography is becoming more widely adopted to support wound care. Thermography has been studied in the medical literature to assess signs of perfusion and inflammation for decades. Bacterial fluorescence has recently emerged as a valuable tool to detect a high bacterial load within wounds. Combining these modalities offers a potential objective screening tool for wound infection.

Methods

A multi-center prospective study of 66 outpatient wound care patients used hyperspectral imaging to collect visible light, thermography, and bacterial fluorescence images. Wounds were assessed and screened using the International Wound Infection Institute (IWII) checklist for CSS of infection. Principal component analysis was performed on the images to identify wounds presenting as infected, inflamed, or non-infected.

Results

The model could accurately predict all three wound classes (infected, inflamed, and non-infected) with an accuracy of 74%. They performed best on infected wounds (100% sensitivity and 91% specificity) compared to non-inflamed (sensitivity 94%, specificity 70%) and inflamed wounds (85% sensitivity, 77% specificity).

Discussion

Combining multiple imaging modalities enables the application of models to improve wound assessment. Infection detection by CSS is vulnerable to subjective interpretation and variability based on clinicians' education and skills. Enabling clinicians to use point-of-care hyperspectral imaging may allow earlier infection detection and intervention, possibly preventing delays in wound healing and minimizing adverse events.

Photo-crosslinked GelMA loaded with dental pulp stem cells and VEGF to repair critical-sized soft tissue defects in rats

BACKGROUND

Tissue engineering of skin and mucosa is essential for the esthetic and functional reconstruction of individuals disfigured by trauma, resection surgery, or severe burns while overcoming the limited amount of autograft and donor site morbidity.

PURPOSE

We aimed to determine whether a combination of Gelatin-methacryloyl (GelMA) hydrogel scaffold alone or loaded with either dental pulp stem cells (DPSCs) and/or vascular endothelial growth factor (VEGF) could improve skin wound healing in rats.

MATERIALS AND METHODS

Four 10 mm full-thickness skin defects were created on the dorsum of 15 Sprague-Dawley rats. The wounds were treated with GelMA alone, GelMA+DPSCs, or GelMA+DPSCs+VEGF. Unprotected wounds were used as controls. Animals were euthanized at 1-, 2-, and 4 weeks post-surgery, and the healing wounds were harvested for clinical, histological, and RT-PCR analysis.

RESULTS

No signs of clinical inflammation were observed among all groups. Few and sparse mononuclear inflammatory cells were observed in GelMA+DPSCs and GelMA+DPSCs+VEGF groups at 2 weeks, with complete epithelialization of the wounds. At 4 weeks, the epidermis in GelMA+DPSCs and GelMA+DPSCs+VEGF groups was indistinguishable from the empty defect and GelMA groups. The decrease in cellularity and increase in density of collagen fibers were observed over time in both GelMA+DPSCs and GelMA+DPSCs+VEGF groups but were more evident in the GelMA+DPSCs+VEGF group. The GelMA+DPSCs+VEGF group showed a higher expression of the KER 10 gene at all time points compared with the other groups. Expression of Col1 A1 and TGFβ-1 were not statistically different over time neither among the groups.

CONCLUSION

GelMA scaffolds loaded with DPSCs, and VEGF accelerated the re-epithelialization of skin wounds.

“Negotiating a new normality” - a longitudinal qualitative exploration of the meaning of living with an open surgical wound

Purpose

Little is known about the experiences of people living with open surgical wounds. These wounds are common and predominantly affect young and actively working people. The aim of this qualitative study was to explore the meaning of living with open surgical wounds.

Methods

A qualitative exploratory study was conducted. We collected data using two individual interviews with each of ten participants (aged between 18–73 years) who had open surgical wounds. Our analytical approach was based on qualitative content analysis. Methods are reported using COREQ guidelines.

Results

We found that the meaning of living with open surgical wounds is shaped by five subthemes: “enduring healing”, “life disruption”, “adapting to a new reality”, “striving for healing” and “returning to normal life;” all under an overarching theme of “negotiating a new normality”.

Conclusion

Participants’ well-being and everyday living are greatly impacted by open surgical wounds. Findings from this study emphasize that open surgical wounds are a long-term condition with a typical “chronicity” trajectory; this brings a new perspective to previous findings of studies on living with complex wounds. This study has also highlighted areas for further research, related to improving individuals’ experience of living with open surgical wounds.

Bacteria-Adhesive Nitric Oxide-Releasing Graphene Oxide Nanoparticles for MRPA-Infected Wound Healing Therapy

A bacteria-infected wound can lead to being life-threatening and raises a great economic burden on the patient. Here, we developed polyethylenimine 1.8k (PEI_1.8k) surface modified NO-releasing polyethylenimine 25k (PEI_25k)-functionalized graphene oxide (GO) nanoparticles (GO-PEI_25k/NO-PEI_1.8k NPs) for enhanced antibacterial activity and infected wound healing via binding to the bacterial surface. In vitro antibacterial activity and in vivo wound healing efficacy in an infected wound model were evaluated compared with NO-releasing NPs (GO-PEI_25k/NO NPs). Surface modification with PEI_1.8k can enhance the ability of nanoparticles to adhere to bacteria. GO-PEI_25k/NO-PEI_1.8k NPs released NO in a sustained manner for 48 h and exhibited the highest bactericidal activity (99.99% killing) against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Pseudomonas aeruginosa (MRPA) without cytotoxicity to L929 mouse fibroblast cells at 0.1 mg/mL. In the MRPA-infected wound model, GO-PEI_25k/NO-PEI_1.8k NPs showed 87% wound size reduction while GO-PEI_25k/NO NPs showed 23% wound size reduction at 9 days postinjury. Masson trichrome and hematoxylin and eosin staining revealed that GO-PEI_25k/NO-PEI_1.8k NPs enhanced re-epithelialization and collagen deposition, which are comparable to healthy mouse skin tissue. GO-PEI_25k/NO-PEI_1.8k NPs hold promise as effective antibacterial and wound healing agents.

Hybrid-Based Wound Dressings: Combination of Synthetic and Biopolymers

Most commercialized wound dressings are polymer-based. Synthetic and natural polymers have been utilized widely for the development of wound dressings. However, the use of natural polymers is limited by their poor mechanical properties, resulting in their combination with synthetic polymers and other materials to enhance their mechanical properties. Natural polymers are mostly affordable, biocompatible, and biodegradable with promising antimicrobial activity. They have been further tailored into unique hybrid wound dressings when combined with synthetic polymers and selected biomaterials. Some important features required in an ideal wound dressing include the capability to prevent bacteria invasion, reduce odor, absorb exudates, be comfortable, facilitate easy application and removal as well as frequent changing, prevent further skin tear and irritation when applied or removed, and provide a moist environment and soothing effect, be permeable to gases, etc. The efficacy of polymers in the design of wound dressings cannot be overemphasized. This review article reports the efficacy of wound dressings prepared from a combination of synthetic and natural polymers.

A Randomized Controlled Trial on the Effect of Local Insulin Glargine on Venous Ulcer Healing

INTRODUCTION

To determine whether the local administration of insulin glargine compared with placebo in nondiabetic patients with venous ulcers (VUs) leads to increased wound healing.

METHODS

A randomized controlled trial using a split-plot design was performed in 36 adults with leg VUs >25 cm² and more than 3 mo of evolution. Each hemi-wound received either 10 UI insulin glargine or saline solution once a day for 7 d. Size of the wounds, thermal asymmetry, the number of blood vessels, and the percentage area of collagen content in wound biopsies were assessed at baseline and after 7 d of treatment. Blood capillary glucose was monitored once a day after the insulin injection.

RESULTS

After 7 d of treatment, the hemi-wounds treated with insulin glargine were significantly smaller, had less thermal asymmetry, more blood vessels, and more collagen content than the saline-treated side. Correlation between thermal asymmetry and the number of blood vessels was also found (r² = 66.2, P < 0.001). No patient presented capillary glucose levels ≤3.3 mmol/L nor any adverse effects.

CONCLUSIONS

In nondiabetic patients with chronic VUs, the topical administration of insulin glargine seems to be safe and promotes wound healing and tissue repair after 7 d of treatment.

The Role of the Extracellular Matrix (ECM) in Wound Healing: A Review

The extracellular matrix (ECM) is a 3-dimensional structure and an essential component in all human tissues. It is comprised of varying proteins, including collagens, elastin, and smaller quantities of structural proteins. Studies have demonstrated the ECM aids in cellular adherence, tissue anchoring, cellular signaling, and recruitment of cells. During times of integumentary injury or damage, either acute or chronic, the ECM is damaged. Through a series of overlapping events called the wound healing phases—hemostasis, inflammation, proliferation, and remodeling—the ECM is synthesized and ideally returned to its native state. This article synthesizes current and historical literature to demonstrate the involvement of the ECM in the varying phases of the wound healing cascade.

Enhanced Bone Remodeling After Fracture Priming

The immune system is an active component of bone repair. Mast cells influence the recruitment of macrophages, osteoclasts and blood vessels into the repair tissue. We hypothesized that if mast cells and other immune cells are sensitized to recognize broken bone, they will mount an increased response to subsequent fractures that may be translated into enhanced healing. To test this, we created a bone defect on the left leg of anesthetized mice and 2 weeks later, a second one on the right leg. Bone repair in the right legs was then compared to control mice that underwent the creation of bilateral window bone defects at the same time. Mice were euthanized at 14 and 56 days. Mineralized tissue quantity and morphometric parameters were assessed using micro-CT and histology. The activity of osteoblasts, osteoclasts, vascular endothelial cells, mast cells, and macrophages was evaluated using histochemistry. Our main findings were (1) no significant differences in the amount of bone produced at 14- or 56 days post-operative between groups; (2) mice exposed to subsequent fractures showed significantly better bone morphometric parameters after 56 days post-operative; and (3) significant increases in the content of blood vessels, osteoclasts, and the number of macrophages in the subsequent fracture group. Our results provide strong evidence that a transient increase in the inflammatory state of a healing injury promotes faster bone remodelling and increased neo-angiogenesis. This phenomenon is also characterized by changes in mast cell and macrophage content that translate into more active recruitment of mesenchymal stromal cells.

Label-Free Quantitative Proteomics to Explore the Action Mechanism of the Pharmaceutical-Grade Triticum vulgare Extract in Speeding Up Keratinocyte Healing

Plant extracts have shown beneficial properties in terms of skin repair, promoting wound healing through a plethora of mechanisms. In particular, the poly-/oligosaccharidic aqueous extract of Triticum vulgare (TVE), as well as TVE-based products, shows interesting biological assets, hastening wound repair. Indeed, TVE acts in the treatment of tissue regeneration mainly on decubitus and venous leg ulcers. Moreover, on scratched monolayers, TVE prompts HaCat cell migration, correctly modulating the expression of metalloproteases toward a physiological matrix remodeling. Here, using the same HaCat-based in vitro scratch model, the TVE effect has been investigated thanks to an LFQ proteomic analysis of HaCat secretomes and immunoblotting. Indeed, the unbiased TVE effect on secreted proteins has not yet been fully understood, and it could be helpful to obtain a comprehensive picture of its bio-pharmacological profile. It has emerged that TVE treatment induces significant up-regulation of several proteins in the secretome (153 to be exact) whereas only a few were down-regulated (72 to be exact). Interestingly, many of the up-regulated proteins are implicated in promoting wound-healing-related processes, such as modulating cell-cell interaction and communication, cell proliferation and differentiation, and prompting cell adhesion and migration.

Accelerative Effect of Cinnamon Nanoparticles as well as HAMLET on Healing of Wounds Infected with MRSA in Diabetic Rats

Objective

The aim of the present study was to investigate the effect of cinnamon nanoparticles (CNPs) on healing of wounds infected with methicillin-resistant Staphylococcus aurous with human alpha-lactalbumin made lethal to tumor cells sensitization in diabetic rats.

Methods

We included fifty diabetic male rats and divided them into 5 groups. There were 10 rats in each group as follows: CONTROL group: we did not infect the CONTROL group. The wound was only covered with sterile saline 0.9% solution (0.1 mL). INFCTD group: in this group, the wounds were infected with MRSA and covered with sterile saline 0.9% solution (0.1 mL). INFCTD-HMLT group: in this group, the wounds were infected with MRSA and HAMLET (100 μg). INFCTD-CNM group: in this group, the wounds were infected with MRSA and 0.1 mL CNPs (1 mg/mL) were applied topically to wounds. INFCTD-HMLT-CNM group: in this group, the wounds were infected with MRSA, HAMLET (100 μg), and 0.1 mL CNPs (1 mg/mL).

Results

Bacteriology, wound area reduction measurements, biochemistry, histomorphometrical studies, hydroxyproline levels, and reverse transcription polymerase chain reaction for caspase-3, Bcl-2, and p53 showed significant difference between rats in the INFCTD-HMT-CNM group in comparison with other groups (P < 0.05).

Conclusions

Accelerated healing of diabetic wounds infected with MRSA showed that local application of cinnamon nanoparticles along with HAMLET sensitization on S. aureus-infected wound could be taken into consideration.

Conductive Biomaterials as Bioactive Wound Dressing for Wound Healing and Skin Tissue Engineering

Conductive biomaterials based on conductive polymers, carbon nanomaterials, or conductive inorganic nanomaterials demonstrate great potential in wound healing and skin tissue engineering, owing to the similar conductivity to human skin, good antioxidant and antibacterial activities, electrically controlled drug delivery, and photothermal effect. However, a review highlights the design and application of conductive biomaterials for wound healing and skin tissue engineering is lacking. In this review, the design and fabrication methods of conductive biomaterials with various structural forms including film, nanofiber, membrane, hydrogel, sponge, foam, and acellular dermal matrix for applications in wound healing and skin tissue engineering and the corresponding mechanism in promoting the healing process were summarized. The approaches that conductive biomaterials realize their great value in healing wounds via three main strategies (electrotherapy, wound dressing, and wound assessment) were reviewed. The application of conductive biomaterials as wound dressing when facing different wounds including acute wound and chronic wound (infected wound and diabetic wound) and for wound monitoring is discussed in detail. The challenges and perspectives in designing and developing multifunctional conductive biomaterials are proposed as well.

Wound Healing Activities and Potential of Selected African Medicinal Plants and Their Synthesized Biogenic Nanoparticles

In Africa, medicinal plants have been traditionally used as a source of medicine for centuries. To date, African medicinal plants continue to play a significant role in the treatment of wounds. Chronic wounds are associated with severe healthcare and socio-economic burdens despite the use of conventional therapies. Emergence of novel wound healing strategies using medicinal plants in conjunction with nanotechnology has the potential to develop efficacious wound healing therapeutics with enhanced wound repair mechanisms. This review identified African medicinal plants and biogenic nanoparticles used to promote wound healing through various mechanisms including improved wound contraction and epithelialization as well as antibacterial, antioxidant and anti-inflammatory activities. To achieve this, electronic databases such as PubMed, Scifinder^® and Google Scholar were used to search for medicinal plants used by the African populace that were scientifically evaluated for their wound healing activities in both in vitro and in vivo models from 2004 to 2021. Additionally, data on the wound healing mechanisms of biogenic nanoparticles synthesized using African medicinal plants is included herein. The continued scientific evaluation of wound healing African medicinal plants and the development of novel nanomaterials using these plants is imperative in a bid to alleviate the detrimental effects of chronic wounds.

An Overview of Cellulose Derivatives-Based Dressings for Wound-Healing Management

Presently, notwithstanding the progress regarding wound-healing management, the treatment of the majority of skin lesions still represents a serious challenge for biomedical and pharmaceutical industries. Thus, the attention of the researchers has turned to the development of novel materials based on cellulose derivatives. Cellulose derivatives are semi-synthetic biopolymers, which exhibit high solubility in water and represent an advantageous alternative to water-insoluble cellulose. These biopolymers possess excellent properties, such as biocompatibility, biodegradability, sustainability, non-toxicity, non-immunogenicity, thermo-gelling behavior, mechanical strength, abundance, low costs, antibacterial effect, and high hydrophilicity. They have an efficient ability to absorb and retain a large quantity of wound exudates in the interstitial sites of their networks and can maintain optimal local moisture. Cellulose derivatives also represent a proper scaffold to incorporate various bioactive agents with beneficial therapeutic effects on skin tissue restoration. Due to these suitable and versatile characteristics, cellulose derivatives are attractive and captivating materials for wound-healing applications. This review presents an extensive overview of recent research regarding promising cellulose derivatives-based materials for the development of multiple biomedical and pharmaceutical applications, such as wound dressings, drug delivery devices, and tissue engineering.

Macroscopic, Histologic, and Immunomodulatory Response of Limb Wounds Following Intravenous Allogeneic Cord Blood-Derived Multipotent Mesenchymal Stromal Cell Therapy in Horses

Limb wounds are common in horses and often develop complications. Intravenous multipotent mesenchymal stromal cell (MSC) therapy is promising but has risks associated with intravenous administration and unknown potential to improve cutaneous wound healing. The objectives were to determine the clinical safety of administering large numbers of allogeneic cord blood-derived MSCs intravenously, and if therapy causes clinically adverse reactions, accelerates wound closure, improves histologic healing, and alters mRNA expression of common wound cytokines. Wounds were created on the metacarpus of 12 horses. Treatment horses were administered 1.51-2.46 × 10⁸ cells suspended in 50% HypoThermosol FRS, and control horses were administered 50% HypoThermosol FRS alone. Epithelialization, contraction, and wound closure rates were determined using planimetric analysis. Wounds were biopsied and evaluated for histologic healing characteristics and cytokine mRNA expression. Days until wound closure was also determined. The results indicate that 3/6 of treatment horses and 1/6 of control horses experienced minor transient reactions. Treatment did not accelerate wound closure or improve histologic healing. Treatment decreased wound size and decreased all measured cytokines except transforming growth factor-β3. MSC intravenous therapy has the potential to decrease limb wound size; however, further work is needed to understand the clinical relevance of adverse reactions.

Chitosan-Coated Poly(lactic acid) Nanofibres Loaded with Essential Oils for Wound Healing

Chronic skin wounds are characterised by a non-healing process that makes necessary the application of wound dressings on the damaged area to promote and facilitate the recovery of skin’s physiological integrity. The aim of the present work is to develop a bioactive dressing that, once applied on the injured tissue, would exert antibacterial activity and promote adhesion and proliferation of fibroblasts. Nanofibres consisting of poly(lactic acid) (PLA) and essential oils (EOs) were electrospun and coated with a medium molecular weight chitosan (CS). Black pepper essential oil (BP-EO) or limonene (L), well-known for their antibacterial properties, were added to the PLA/acetone solution before electrospinning; phase separation phenomena occurred due to the poor solubility of the EOs in the PLA solution and led to fibres having surface nano-pores. The porous electrospun fibres were coated with CS to produce hydrophilic membranes that were easy to handle, biocompatible, and suited to promote cellular proliferation. The fibrous scaffolds were tested in terms of mechanical resistance, wettability, antibacterial activity, in-vitro cytotoxicity, and ability to promote fibroblasts’ adhesion and proliferation. The results obtained proved that the CS coating improved the hydrophilicity of the fibrous mats, enhanced EO’s antibacterial potential, and promoted cell adhesion and proliferation.

Acellular Dermal Matrix Used in Diabetic Foot Ulcers: Clinical Outcomes Supported by Biochemical and Histological Analyses

Diabetic foot ulcer (DFU) is a diabetes complication which greatly impacts the patient's quality of life, often leading to amputation of the affected limb unless there is a timely and adequate management of the patient. DFUs have a high economic impact for the national health system. Data have indeed shown that DFUs are a major cause of hospitalization for patients with diabetes. Based on that, DFUs represent a very important challenge for the national health system. Especially in developed countries diabetic patients are increasing at a very high rate and as expected, also the incidence of DFUs is increasing due to longevity of diabetic patients in the western population. Herein, the surgical approach focused on the targeted use of the acellular dermal matrix has been integrated with biochemical and morphological/histological analyses to obtain evidence-based information on the mechanisms underlying tissue regeneration. In this research report, the clinical results indicated decreased postoperative wound infection levels and a short healing time, with a sound regeneration of tissues. Here we demonstrate that the key biomarkers of wound healing process are activated at gene expression level and also synthesis of collagen I, collagen III and elastin is prompted and modulated within the 28-day period of observation. These analyses were run on five patients treated with Integra® sheet and five treated with the injectable matrix Integra® Flowable, for cavitary lesions. In fact, clinical evaluation of improved healing was, for the first time, supported by biochemical and histological analyses. For these reasons, the present work opens a new scenario in DFUs treatment and follow-up, laying the foundation for a tailored protocol towards complete healing in severe pathological conditions.

Antlerogenic stem cells extract accelerate chronic wound healing: a preliminary study

BACKGROUND

Chronic wounds constitute a significant medical and social problem. Chronic wound treatment may be supported by various techniques, such as negative pressure therapy, phototherapy or stem cells therapy, yet most of those supporting therapies need more evidence to be used for standard wound care. Current study covers the use of sonicated Antlerogenic Stem Cells (ASC) extract on chronic wounds.

METHODS

Study was performed on 20 dermatological patients with venous leg ulcers, divided into two groups - treated with and without ASC extract respectively. The area and circumference of the wounds during the follow-up visits were measured on the wound imprint. Dynamics of wound healing was determined and compared between control and study group; statistics includes changes in absolute values (wound area, circumference), as well as relative (percentage of wound decrease, circumference/area ratio) and their change in time. For the purpose of Ki-67 immunohistochemical staining, sections were sampled from the wound edge at distinct check-points during therapy. Results of both groups were compared with Student test or Mann-Whitney test, depending on results distribution.

RESULTS

Besides Ki-67 expression, all tested wound healing parameters (including relative and absolute wound decrease and changes in circumference/area ratio) were statistically significant more favorable in experimental group.

CONCLUSION

ASC extract significantly supported standard chronic wound treatment. Due to small population of study the results should be considered preliminary, yet promising for further research.

The frequently dismissed importance of properly sampling skin bruises

The correct interpretation of skin lesions is a crucial issue in forensic medicine. Many macroscopic and microscopic vital reaction markers and molecules have been studied in the past years in order to estimate the timing of injuries. However, literature lacks information regarding how to perform sampling to obtain a more reliable and accurate response. The present study investigates 25 bruises and analyses the different histological asset in different areas (central or marginal) and the different layers (epidermis, dermis, hypodermis and muscle) of the wound. All wounds were sampled in several areas and analysed under a 200× magnification optical microscope, simply counting the degree of haemorrhaging (i.e hematic infiltration) visible in each optical field (0 = 0%-5%; 1 = 6%-25%; 2 = 26%-50%; 3 = 51%-75%; 4 = 76%-100%). All the injuries presented some kind of infiltration in at least one area, nonetheless only 56% of the wounds were infiltrated in the entirety of the areas. Finally, in 28% the dermal layer did not show any trace of infiltration. Therefore, considering such results it seems that depth or area of sampling of a bruise may largely influence the evaluation of vitality and hence of age of a wound. Though this may seem intuitive, no studies have examined this issue in depth.

Anti-inflammatory, wound healing and antioxidant potential of compounds from Dioscorea bulbifera L. bulbils

BACKGROUND

Dioscorea bulbifera L. (Dioscoreaceae) has been traditionally used in Thai folk medicine as a diuretic and anthelmintic, for longevity preparations, and for wound and inflammation treatment. This plant is also commonly used in traditional Indian and Chinese medicines in the treatment of sore throat, gastric cancer, rectal carcinoma and goiters. However, the wound healing effects of the active compounds in this plant have not been investigated.

OBJECTIVE

This study aimed to identify compounds responsible for the wound healing activity of D. bulbifera and determine their potential anti-inflammatory and antioxidant activities.

METHODS

Crude extracts of D. bulbifera bulbils, their derived fractions and eleven purified compounds were tested for anti-inflammatory activity against LPS-induced NO production in RAW264.7 macrophages. The wound healing effects were evaluated via cell proliferation and migration assays using human dermal fibroblasts (HDFs), and the antioxidant effects were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical (•OH) scavenging activity assays.

RESULTS

15,16-Epoxy-6α-O-acetyl-8β-hydroxy-19-nor-clero-13(16),14-diene-17,12;18,2-diolide (2), (+)-catechin (5), quercetin (6) and myricetin (11) exhibited significantly potent wound healing effects and promoted marked cell proliferation, resulting in % viabilities of 107.4-137.6, 121.1-151.9, 98.0-131.9, 90.9-115.9, respectively. Among them, (+)-catechin produced the highest % cell migration, resulting in 100.0% wound closure sooner (at day 2) than the other compounds. In addition, 1 μg/ml (+)-catechin significantly increased fibroblast migration by 2.4-fold compared to that in the control after 24 h. Regarding anti-inflammatory properties, kaempferol (7) and quercetin (6) decreased (p < 0.005) NO production, with IC50 values of 46.6 and 56.2 μM, respectively. In addition, the crude extracts, solvent fractions and flavonoid compounds were also found to possess marked antioxidant activity in both DPPH and •OH radical scavenging assays.

CONCLUSIONS

These findings provide more evidence to support the traditional use of D. bulbifera for the treatment of wounds and inflammation.

Curcumin Nanoparticles Improved Diabetic Wounds Infected With Methicillin-Resistant Staphylococcus aureus Sensitized With HAMLET

Accurately orchestrated course of events normally observed in healing are not followed in diabetic wounds, and bacterial colonization/infection further messes up the process. Novel therapeutic options for treatment of infections caused by multidrug-resistant Staphylococcus aureus are urgently needed. HAMLET (human α-lactalbumin made lethal to tumor cells) has been reported to be able to sensitize bacterial pathogens to traditional antimicrobial agents. The aim was to assess the wound healing activity of curcumin nanoparticles in diabetic wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) sensitized with HAMLET. Fifty male rats were randomized into 5 groups of 10 animals each. In CONTROL group, 0.1-mL sterile saline 0.9% solution was added to the wounds with no infection. In MRSA group, the wounds were infected with MRSA and only treated with 0.1-mL sterile saline 0.9% solution. In MRSA/HAMLET group, infected wounds were treated with HAMLET (100 µg). In MRSA/CNP group, animals with infected wounds were treated with 0.1 mL topical application of 1 mg/mL curcumin nanoparticles. In MRSA/CNP/HAMLET group, animals with infected wounds were treated with topical application of 0.1 mL solution of curcumin nanoparticles (1 mg/mL) and HAMLET (100 µg). All test formulations were applied for 10 days, twice a day, starting from first treatment. Microbiological examination; planimetric, biochemical, histological, and quantitative morphometric studies; immunohistochemical staining for angiogenesis; determination of hydroxyproline levels; and reverse transcription polymerase chain reaction for caspase 3, Bcl-2, and p53 showed that there was significant difference between animals in MRSA/CNP/HAMLET group compared with other groups (P < .05). Curcumin nanoparticles improved diabetic wounds infected with MRSA sensitized with HAMLET and had the potential to offer more attention to this safer agent for topical use in infected diabetic wounds.

Palatal Wound Healing with Primary Intention in a Rat Model-Histology and Immunohistomorphometry

Background and objectives: Subepithelial connective tissue graft (SCTG) from the palate has been considered as the “gold standard” for the treatment of deep gingival recessions. A single-incision technique was reported to allow primary wound healing. A palatal single incision was performed in a rat model. The present study assessed the histology and histomorphometry of palatal wound healing following surgical closure with primary intention. Materials and Methods: Twenty-six 6-month-old male Wistar rats weighing 427–650 g. An incision was made on the maxillary palate. A full thickness flap was raised palatally, and then repositioned and sutured. Two experimental groups: S—Study group, I—Intact control group. Half of the animals were sacrificed 7 days and the remaining 14 days postoperatively. Outcome parameters included—epithelial gap; inflammatory infiltration; vascular fraction, expression of myofibroblasts and stem cell markers within the oral epithelium and stromal cells and physical properties of stromal collagen fibers. Investigations were performed at two time-points (7 and 14 days) during the wound healing process. Results: The epithelial gap closed completely after 14 days. The inflammatory reaction and vascular fraction were relatively low. Surgical trauma downregulated the expression of cytokeratin (CK) 14 and CK 15, which returned to normal after 14 days. Epithelial differentiation was mediated through upregulation of connective tissue sex- determining-region-Y-box2 (SOX2). Epithelial SOX2, CD34, alpha smooth muscle actin (αSMA) and physical properties of stromal collagen fibers were not influenced by the surgical trauma. Conclusions: Surgical trauma followed by palatal wound healing with primary intention in a rat model heals within 14 days. It induces minimal inflammatory infiltration and vascular proliferation. Epithelization is exerted through promotion of epithelial differentiation from stem cells by connective tissue SOX2.

Exploring Incontinence-Associated Dermatitis in a Single Center Intensive Care Unit: A Longitudinal Point Prevalence Survey

PURPOSE

The purpose of this study was to provide longitudinal prevalence rates of incontinence-associated dermatitis (IAD) in patients in an intensive care unit (ICU) and to identify patient characteristics associated with IAD development.

DESIGN

Prospective observational.

SUBJECTS AND SETTING

The sample comprised 351 patients aged 18 years and older in a major metropolitan public hospital ICU in Queensland, Australia.

METHODS

All consenting, eligible participants at risk of developing IAD underwent weekly skin inspections to determine the presence of IAD. Data were collected weekly for 52 consecutive weeks. Descriptive statistics described the study sample and logistic regression analysis was used to identify patient characteristics associated with development of IAD.

RESULTS

The weekly IAD prevalence ranged between 0% and 70%, with IAD developing in 17% (n = 59/351) of ICU patients. The odds of IAD developing increased statistically significantly with increasing age (odds ratio [OR]: 1.029, 95% confidence interval [CI]: 1.005-1.054, P = .016), time in the ICU (OR = 1.104; 95% CI: 1.063-1.147, P < .001), and Bristol Stool chart score (OR = 4.363, 95% CI: 2.091-9.106, P < .001). Patients with respiratory (OR = 3.657, 95% CI: 1.399-9.563, P = .008) and sepsis (OR = 3.230, 95% CI: 1.281-8.146, P = .013) diagnoses had increased odds of developing IAD.

CONCLUSIONS

These data show the high variability of IAD prevalence over a 1-year period. Characteristics associated with the development of IAD in patients in the ICU included older age, longer lengths of ICU stay, incontinent of liquid feces, and having respiratory or sepsis diagnoses.

Selection of Appropriate Wound Dressing for Various Wounds

There are many factors involved in wound healing, and the healing process is not static. The therapeutic effect of modern wound dressings in the clinical management of wounds is documented. However, there are few reports regarding the reasonable selection of dressings for certain types of wounds in the clinic. In this article, we retrospect the history of wound dressing development and the classification of modern wound dressings. In addition, the pros and cons of mainstream modern wound dressings for the healing of different wounds, such as diabetic foot ulcers, pressure ulcers, burns and scalds, and chronic leg ulcers, as well as the physiological mechanisms involved in wound healing are summarized. This article provides a clinical guideline for selecting suitable wound dressings according to the types of wounds.

Anti-fibrosis activity of quercetin attenuates rabbit tracheal stenosis via the TGF-β/AKT/mTOR signaling pathway

AIMS

This study aimed to explore the possible mechanism of trauma-induced laryngotracheal stenosis and potential protective and therapeutic efficacy of quercetin on trauma-induced laryngotracheal stenosis.

MAIN METHODS

The expression and activity of fibrotic factors [interleukin (IL)-6, IL-8, autophagy related 5 (ATG5), collagen (COL)-1, tumor growth factor (TGF)-β COL-3, microtubule-associated proteins 1A/1B light chain 3A (LC3), and vascular endothelial growth factor (VEGF)] and fibrotic signaling mediators [mammalian target of rapamycin (mTOR) and phosphorylated AKT (pAKT)] were detected by real-time quantitative PCR (qRT-PCR), ELISA, Western blot, and immunohistochemical staining, respectively, in the lipopolysaccharide (LPS)-induced WI-38 (a human embryonic lung fibroblast cell line) cellular fibrotic model and a trauma-induced rabbit tracheal stenosis model, with and without quercetin treatment.

KEY FINDINGS

Pre-treatment with quercetin significantly reversed the LPS-induced upregulation of pro-fibrotic factors (IL-6, IL-8, COL-1, COL-3, LC3) and fibrotic signaling mediators (mTOR and AKT), and it induced the downregulation of ATG5 in the WI-38 cells. Furthermore, the anti-fibrotic activity of quercetin was confirmed in the trauma-induced rabbit tracheal stenosis model. Thus, the nasogastric administration of quercetin attenuated the tracheal stenosis of the rabbit tracheal stenosis model, in addition to effectively reversing an increase in pro-fibrotic factors (VEGF, IL-6, TGF-β, COL-1, and COL-3) and fibrotic signaling mediators (mTOR and AKT), as well as downregulating ATG5 of the rabbit tracheal stenosis model.

SIGNIFICANCE

Quercetin exhibits anti-fibrotic activity by inhibiting pro-fibrotic factors and AKT/mTOR signaling pathway, in addition to activating autophagy activity. This study provided experimental evidence supporting the application of quercetin in tracheal stenosis, clinically.

Ali R, Abd. Hamid R, Chang SK, Rahman MH, Zainal Z, Khaza’ai H. Temporal changes in the cell population and wound healing-related gene expression in deep partial-thickness burn wound model

Background

Burns are injuries that lie on the skin or other organic tissues caused by exposures to the heat, electricity, chemicals or ionizing radiation. The present study was carried out to record temporal changes in the cell population and wound healing-related gene expression in rats with deep partial-thickness burn.

Methods

Burn wound was induced on the dorsal part of Sprague-Dawley rats using temperature-regulated 20-mm wide aluminum head heating device. Animals were then sacrificed on days three, seven, 11, 14 and 21 post-burn, respectively. Half of the wounded skin tissues were dissected and fixed in buffered neutral formalin for Hematoxylin & Eosin (H&E) staining, and the other half were cut off and stored in − 20 °C for real-time PCR analyses.

Results

The number of adipose cells was found to be maximal on the 3rd day post-burn, and it gradually decreased over time and completely disappeared on day 11 post-burn. The maximum number of neutrophils were found to be on the 3rd and 14th day post-burn, while the maximum number of myofibroblasts were found on the 11th day post-burn. The number of lymphocytes did not change too much during the whole healing process. At the gene expression level, the expression pattern of inflammation-related genes including IL-6, TNF-α and iNOS were similar, which was found to be increased from day 3 to day 11 and decreased thereafter. Angiogenesis related genes including both VEGF-A and TGF-β1 showed a same expression pattern, both of which were slightly increased from day 3 to day 14 and smoothly decreased on day 21 post-burn. Matrix re-modeling related genes including MMP-2, TIMP-2 and Collagen-1 changed over time synchronously, where they all persistently increased from day 3 till day 14, then slightly declined on day 21 post-burn.

Conclusion

The present study revealed the changes in the cell population and expression profile of wound healing-related genes in deep partial-thickness burn, which could provide a cellular and genomic basis for the future research of burn injuries.

Silica-based nanosystems for therapeutic applications in the skin

Aging, exposure to oxidants, infectious pathogens, inflammogens, ultraviolet radiation and other environmental and genetic factors can result in the development of various skin disorders. Despite immense progress being made in dermatological treatments, many skin-associated problems still remain difficult to treat and various therapies have limitations. Progress in silica-based nanomaterials research provides an opportunity to overcome these drawbacks and improve therapies and is a promising tool for inclusion in clinical practice to treat skin diseases. This review focuses on the use of various types of silica nanoparticles with therapeutic applications in various skin disorders. These nanosystems improve treatment efficacy by maintaining or enhancing the effect of several drugs and are useful tools for nanomedicine, pharmaceutical sciences and future clinical applications.

Regeneration and Repair of Skin Wounds: Various Strategies for Treatment

Skin as a mechanical barrier between the inner and outer environment of our body protects us against infection and electrolyte loss. This organ consists of 3 layers: the epidermis, dermis, and hypodermis. Any disruption in the integrity of skin leads to the formation of wounds, which are divided into 2 main categories: acute wounds and chronic wounds. Generally, acute wounds heal relatively faster. In contrast to acute wounds, closure of chronic wounds is delayed by 3 months after the initial insult. Treatment of chronic wounds has been one of the most challenging issues in the field of regenerative medicine, promoting scientists to develop various therapeutic strategies for a fast, qualified, and most cost-effective treatment modality. Here, we reviewed more recent approaches, including the development of stem cell therapy, tissue-engineered skin substitutes, and skin equivalents, for the healing of complex wounds.

Effect of a single dose of subcutaneous meloxicam before knife castration alone or combined with hot-iron branding on scrotal healing, inflammatory response, and behaviour in 2-mo-old beef calves over 42 d post procedure

The objective of this study was to evaluate the effect of a single subcutaneous injection of meloxicam on scrotal healing, inflammatory response, and behaviour in castrated or castrated and branded beef calves for 42 d post procedure. Seventy-two 2-mo-old Angus crossbred bull calves were used to assess the effects of procedure (Trt): (1) sham control, (2) knife castration, and (3) knife castration and hot-iron branding; and pain mitigation (Med): (1) nonmedicated and (2) medicated with meloxicam according to a 3 × 2 factorial design. Body weight, scrotal circumference (SC), and healing scores were collected weekly until day 42. Blood samples were collected weekly until day 42 to assess haptoglobin, serum amyloid-A, and complete blood cell count. Hair was collected on day −1 and day 42 to assess cortisol concentrations. Lying and standing behaviour were recorded for 42 d, whereas pain-related behaviours were recorded on days 7, 15, 22, 29, and 34 post procedure. The inflammatory response (SC) and duration of standing was greater (P < 0.05) in calves castrated and branded than those only castrated. However, meloxicam did not reduce inflammation or improve wound healing in either castrated or castrated and branded calves.

Evaluating treatments with topical anaesthetic and buccal meloxicam for pain and inflammation caused by amputation dehorning of calves

To assess the effects of a topical anaesthetic (TA) and buccal meloxicam (BM) on behaviour, maximum wound temperature and wound morphology following amputation dehorning of beef calves, 50 unweaned Hereford calves were randomly allocated to: (1) sham dehorning / control (CON, n = 14); (2) amputation dehorning (D, n = 12); (3) amputation dehorning with pre-operative buccal meloxicam (DBM, n = 12); and (4) amputation dehorning with post-operative topical anaesthetic (DTA, n = 12). Videos of the calves were captured for 3 h following treatment. Each calf was later observed for 5 min every hour and the frequency and duration of specific behaviours displayed during these focal periods was recorded. Infrared and digital photographs of dehorning wounds were collected from all dehorned calves on days 1, 3 and 7 following treatment. Infrared photographs were used to identify the maximum temperature within the wound area. Digital photographs were used to score wounds based on visual signs of inflammation and healing, using a numerical rating scale of 1 to 3, with morphological aspects of inflammation increasing and morphological aspects of healing decreasing with progressive scores. CON calves displayed fewer head shakes than all dehorned calves at 2 and 3 h following treatment (P = 0.025). CON and DTA calves displayed less head turns than DBM calves at 2 h following treatment (P = 0.036). CON calves displayed fewer combined point behaviours than all dehorned calves at 2 h following treatment (P = 0.037). All dehorning wounds had a greater maximum temperature on days 3 and 7 compared to day 1 (P = 0.003). All wound morphology scores decreased from day 1 to day 3 and wound morphology scores of DBM and DTA calves increased from day 3 to day 7 (P = 0.03). Although flystrike may have confounded these observations, no clear effects of TA or BM on behaviour, maximum wound temperature or wound morphology following dehorning of calves were observed. Further research is required to evaluate the analgesic efficacy of these products for amputation dehorning of calves.

Effects of topical anaesthetic and buccal meloxicam on average daily gain, behaviour and inflammation of unweaned beef calves following surgical castration

Although the pain caused by castration of calves is a significant animal welfare issue for the beef industry, analgesia is not always used for this procedure, largely because of practical limitations associated with injectable forms of pain relief. Novel analgesic formulations have now been developed for livestock to allow topical and buccal administration, offering practical options to improve cattle welfare if shown to be effective. To assess the effects of topical anaesthetic (TA) and buccal meloxicam (BM) on average daily gain (ADG), behaviour and inflammation following surgical castration of beef calves, a total of 50 unweaned bull calves were randomly allocated to: (1) sham castration (SHAM, n=10); (2) surgical castration (C, n=10); (3) surgical castration with pre-operative buccal meloxicam (CBM, n=10); (4) surgical castration with post-operative topical anaesthetic (CTA, n=10); and (5) surgical castration with pre-operative buccal meloxicam and post-operative topical anaesthetic (CBMTA, n=10). Calves were recorded on video for 5 h following treatment and the frequency and duration of specific behaviours displayed by each animal was later observed for 5 min every hour (total of 25 min). Average daily gain was calculated 1, 2 and 6 days following treatment. Scrotal diameter measurements and photographs of wounds were collected from all castrated calves 1, 2 and 6 days following treatment to evaluate inflammation and wound healing. Infrared photographs were used to identify maximum scrotal temperature. Digital photographs were used to visually score wounds on a numerical rating scale of 1 to 5, with signs of inflammation increasing and signs of healing decreasing with progressive scores. Sham castration calves displayed significantly less, and C calves displayed significantly more foot stamps than all other calves (P=0.005). Observations on the duration of time that calves displayed a hypometric 'stiff gait' locomotion, indicated that SHAM calves tended to spend no time, C calves tended to spend the greatest time and all other calves tended to spend an intermediate time displaying this behaviour (P=0.06). Maximum scrotal temperatures were lower in CBM and CBMTA calves than C and CTA calves 2 days following treatment (P=0.004). There was no significant effect of treatment on ADG (P=0.7), scrotal diameter (P=0.09) or wound morphology score (P=0.5). These results suggest that TA and BM, alone or in combination, reduced pain and BM reduced inflammation following surgical castration of calves.

Adipose derived stem cell conditioned medium effect on proliferation phase of wound healing in Sprague Dawley rat

Background: Disintegration of skin tissue can lead to disability and death. Recent studies on wound therapy applied stem cells and adipose derived stem cell conditioned medium (ADSC-CM) to improve wound healing. However, the role of ADSC-CM in wound healing mechanism in terms of angiogenesis, quantity of collagen, and epithelialization is not fully understood. Therefore, this study aimed to analyze the levels of growth factors (VEGF and EGF) in ADSC-CM and histological features of angiogenesis, epithelialization, and collagen density after skin incision in Sprague Dawley rats.Methods: Thirty rats were injured at the back (full thickness wound) and treated topically with ADSC-CM, culture medium, basal medium, and without treatment. Mice were sacrificed on days 3, 7, 14, 21 and 28. After sacrificed, tissue samples were examined microscopically to assess angiogenesis, epithelialization, and collagen density. Concentrations of VEGF and EGF in ADSC-CM were measured by ELISA.Results: Clinically, wound that was treated with ADSC-CM showed improvement in wound healing process. ADSC-CM treated wound showed the highest epithelialization ratio and the fastest wound closure.Conclusion: There were no statistical significant differences between groups that were treated with ADSC-CM and not. However, topical ADSC-CM treated wound revealed a better clinical improvement in epithelialization.

The gestational power of mast cells in the injured tissue

The inflammatory response expressed after wound healing would be the recapitulation of systemic extra-embryonic functions, which would focus on the interstitium of the injured tissue. In the injured tissue, mast cells, provided for a great functional heterogeneity, could play the leading role in the re-expression of extra-embryonic functions, i.e., coelomic-amniotic and trophoblastic-vitelline. Moreover, mast cells would favor the production of a gastrulation-like process, which in certain tissues and organs would induce the regeneration of the injured tissue. Therefore, the engraftment of mesenchymal stem cells and mast cells, both with an extra-embryonic regenerative phenotype, would achieve a blastema, from the repaired and regenerated injured tissue, rather than by fibrosis, which is commonly made through wound-healing.

In vitro and in vivo evaluation of effectiveness of a novel TEMPO-oxidized cellulose nanofiber-silk fibroin scaffold in wound healing

In this study, a novel TEMPO-oxidized cellulose nanofiber (TOCN)-silk fibroin scaffold was prepared using a cost effective freeze drying method. Fundamental physical characterizations were carried out by scanning electron microscopy (SEM), pore diameter determination, FT-IR. PBS uptake behavior of the scaffold showed that, silk fibroin can enhance the swelling capacity of TOCN. L929 primary fibroblast cell was selected for in vitro studies, which showed that the scaffolds facilitated growth of cells. In vivo evaluation of TOCN, TOCN-silk fibroin composites was examined using critical sized rat skin excisional model for one and two weeks. The results of rat wound model revealed that, compared to only TOCN scaffold, TOCN-silk fibroin scaffold successfully promoted wound healing by the expression of wound healing markers. TOCN-silk fibroin 2% has the fastest wound healing capacity. Thus, it appears that TOCN-silk fibroin composite scaffolds can be useful as wound healing material in clinical applications.

Chitosan Associated with the Extract of Unripe Banana Peel for Potential Wound Dressing Application

The authors report the preparation of chitosan membranes associated with the extract of unripe banana peel. Extracts were prepared by decoction, using boiling distilled water. The extraction process was repeated three times. First and third extracts served as solvent to prepare chitosan membranes by solvent evaporation technique. The chitosan membranes associated with the first and third extracts of unripe banana peel exhibit good flexibility, transparency, and uniformity. Scanning Electron Microscopy images showed dense membranes. Brownish color of membranes was observed due to the presence of tannins, which was confirmed by Infrared Spectroscopy analysis. Thermal properties of the membranes were evaluated by Differential Scanning Calorimetry (DSC), which exhibited good thermal stability at physiological temperature (37°C). At this temperature and pH 7.2, membranes were also able to absorb fluids. The hydrophilic character of the membranes was determined by contact angle measurements. The membranes demonstrated their capacity for gaseous exchange and exhibited water-vapor permeability (WVP) rates comparable to injured skin one. Finally, high number of viable dermal fibroblasts was observed by indirect cytotoxicity assay suggesting potential application of these membranes as skin wound dressing.

Preparation of copper-containing bioactive glass/eggshell membrane nanocomposites for improving angiogenesis, antibacterial activity and wound healing

Effectively stimulating angiogenesis and avoiding wound infection are great challenges in wound care management. Designing new healing dressings with requisite angiogenic capacity and antibacterial performance is of particular significance. In order to achieve this aim, we prepared a copper (Cu)-containing bioactive glass nanocoating (40-50nm) with uniform nanostructure on natural eggshell membrane (Cu-BG/ESM) by the pulsed laser deposition (PLD) technique. The surface physicochemical properties including hydrophilicity and hardness of ESM were significantly improved after depositing Cu-BG nanocoatings. Meanwhile, 5Cu-BG/ESM films containing 5mol% Cu stimulated proangiogenesis by improving vascular endothelial growth factor (VEGF) and hypoxia-inducible factor (HIF)-1α protein secretion as well as angiogenesis-related gene expression (VEGF, HIF-1α, VEGF receptor 2 (KDR) and endothelial nitric oxide (eNos)) of human umbilical vein endothelial cells (HUVECs). When used to treat full-thickness skin defects in mice, 5Cu-BG/ESM films enhanced the healing quality as confirmed by the significantly improved angiogenesis (as indicated by CD31 expression) and formation of continuous and uniform epidermis layer in vivo. Furthermore, 5Cu-BG/ESM films could maintain a sustained release of Cu(2+) ions and distinctly inhibited the viability of bacteria (Escherichia coli). The results indicate that Cu(2+) ions released from Cu-BG/ESM nanocomposite films play an important role for improving both angiogenesis and antibacterial activity and the prepared nanocomposite films combined Cu-containing BG nanocoatings with ESM are a promising biomaterial for wound healing application.

STATEMENT OF SIGNIFICANCE

Designing new healing dressings with requisite angiogenic capacity and antibacterial performance is of particular significance in wound care management. In our study, we successfully prepared copper-containing bioactive glass/eggshell membrane (Cu-BG/ESM) nanocomposites with uniform bioactive glass nanocoatings by using pulsed laser deposition (PLD) technology. Due to the deposited Cu-BG nanocoatings on the surface of ESM, Cu-BG/ESM nanocomposites possessed significantly improved physicochemical and biological properties, including surface hydrophilicity, hardness, antibacterial ability, angiogenesis rate in vitro and wound healing quality in vivo as compared to pure ESM and BG/ESM films. Our study showed that prepared nanocoatings on Cu-BG/ESM nanocomposites offer a beneficial carrier for sustained release of Cu(2+) ions which played a key role for improving both angiogenesis and antibacterial activity. The prepared nanocomposites combined Cu-containing BG nanocoatings with ESM are a promising biomaterial for wound healing application.

Composite wound dressings of pectin and gelatin with aloe vera and curcumin as bioactive agents

Aloe vera and curcumin loaded oxidized pectin-gelatin (OP-Gel) matrices were used as antimicrobial finishes on nonwoven cotton fabrics to produce composite wound care devices. The drug release characteristics of the biocomposite dressings indicated that curcumin is released through a biphasic mechanism - erosion of the polymeric matrix, followed by diffusion, while aloe vera is released upon leaching of the polymeric matrix. A 50/50 composition of aloe vera/curcumin was used to fabricate OP-Gel-Aloe Curcumin dressings. However, contrary to our expectations, OP-Gel-Aloe Curcumin dressings exhibited lesser antimicrobial activity compared to OP-Gel-Aloe and OP-Gel-Curcumin dressings. The cytocompatibility of the fabricated dressings was evaluated using NIH3T3 mouse fibroblast cells. OP-Gel-Aloe treated fibroblasts had the highest viability, with the matrices providing a substrate for good cell attachment and proliferation. On the other hand, OP-Gel-Curcumin and OP-Gel-Aloe Curcumin seemed to have induced apoptosis in NIH3T3 cells. In vivo wound healing analysis was carried out using an excisional splint wound model on C57BL/6J mice. OP-Gel-Aloe treated wounds exhibited very rapid healing with 80% of the wound healing in just 8 days. Furthermore, aloe vera exerted a strong anti-inflammatory effect and prominent scar prevention. Histological examination revealed that an ordered collagen formation and neovascularization could be observed along with migration of nuclei. Therefore, OP-Gel-Aloe biocomposite dressings are proposed as viable materials for effective wound management.