Wound Healing Update

Porous Deproteinized Natural Rubber Film Loaded with Silver Nanoparticles for Topical Drug Delivery

The work demonstrated the use of natural rubber for topical drug delivery. The first objective was to fabricate a porous deproteinized natural rubber film loaded with silver nanoparticles. Characterizing and assessing its formulation was the second objective. Surface pH, mechanical properties, swelling ratio, erosion, moisture vapor transmission rate, scanning electron microscopy/energy dispersive X-ray analysis, and X-ray diffraction were evaluated. In vitro studies and antibacterial activity were assessed. It was discovered that silver nanoparticles could enter the film and that their concentrations ranged between 7.25 and 21.03 µg/cm2. The pH of the film's surface was 7.00. The mechanical properties of the film with silver nanoparticle loading differed from the blank film. After adding silver nanoparticles, the film eroded faster than before, but the swelling ratio was not affected significantly. Increased time utilization had an impact on the moisture vapor transmission rate of the film. Silver nanoparticles released easily from the film while there was less permeability. The dead pig-ear skin had significant silver nanoparticle accumulation. Potent antibacterial activity was seen in the film containing silver nanoparticles. The silver nanoparticle-loaded film may be used as a wound dressing for a topical film that promotes wound healing while also protecting the area from infection.

Growth Factor Loaded Thermo-Responsive Injectable Hydrogel for Enhancing Diabetic Wound Healing

Background: Diabetic wound (DW) is the most devastating complication resulting in significant mortality and morbidity in diabetic patients. The objective of the current study was to formulate Epidermal Growth Factor loaded Chitosan nanoparticle impregnated with thermos-responsive injectable hydrogel with protease inhibitor. EGF, shown in all stages of wound healing from inflammation to proliferation and remodelling, combined with Doxycycline, a well-known anti-inflammatory and anti-bacterial drug, could be a better strategy in diabetic wound healing. However, EGF's low stability makes it difficult to use. Methodology: The nanoparticles were prepared using the ionic gelation method. The prepared nanoparticles were evaluated for particle size, zeta potential, entrapment efficiency, and SEM studies. Further, the optimized nanoparticle batch was loaded into hydrogel with a protease inhibitor. The hydrogel was evaluated for morphology, protease degradation, in vitro drug release, anti-bacterial activity, cell migration, in vitro cell biocompatibility, and in vivo wound healing studies. Results and Conclusion: The particle size analysis of nanoparticles revealed the size (203 ± 1.236 nm), Zeta potential (+28.5 ± 1.0 mV), and entrapment efficiency of 83.430 ± 1.8%, respectively. The hydrogel showed good porous morphology, injectability, thermo-responsive, biocompatibility, and controlled drug release. In vitro anti-bacterial studies revealed the potential anti-bacterial activity of doxycycline against various microbes. In vivo data indicated that combining EGF and DOX considerably reduced inflammation time-dependent than single-agent treatment. Furthermore, histological studies corroborated these findings. After topical application of hydrogel, histopathology studies revealed significant collagen synthesis and a fully regenerated epithelial layer and advancement in all three stages (proliferation, remodelling, and maturation), which are required to improve the diabetic wound healing process by any dressing. These findings demonstrated that hydrogel promoted cutaneous wound healing in STZ-induced rats by suppressing inflammation at the wound site. Furthermore, histological studies corroborated these findings. After topical application of hydrogel, histopathology studies revealed significant collagen synthesis, a fully regenerated epithelial layer, and advancement in all three stages (proliferation, remodelling, and maturation), which are required to improve the diabetic wound healing process by any dressing. These findings demonstrated that hydrogel promoted cutaneous wound healing in STZ-induced rats by suppressing inflammation at the wound site.

Current Advances in the Development of Hydrogel-Based Wound Dressings for Diabetic Foot Ulcer Treatment

Diabetic foot ulcers (DFUs) are one of the most prevalent complications associated with diabetes mellitus. DFUs are chronic injuries that often lead to non-traumatic lower extremity amputations, due to persistent infection and other ulcer-related side effects. Moreover, these complications represent a significant economic burden for the healthcare system, as expensive medical interventions are required. In addition to this, the clinical treatments that are currently available have only proven moderately effective, evidencing a great need to develop novel strategies for the improved treatment of DFUs. Hydrogels are three-dimensional systems that can be fabricated from natural and/or synthetic polymers. Due to their unique versatility, tunability, and hydrophilic properties, these materials have been extensively studied for different types of biomedical applications, including drug delivery and tissue engineering applications. Therefore, this review paper addresses the most recent advances in hydrogel wound dressings for effective DFU treatment, providing an overview of current perspectives and challenges in this research field.

Angiogenic Hydrogels to Accelerate Early Wound Healing

The metabolic disorder diabetes mellitus affects an increasing proportion of the population, a number projected to double by 2060. Non-life-threatening comorbidities contribute to an interrupted healing process which is first delayed, then prolonged, and associated with increased susceptibility to infection and sustained and unresolved inflammation. This leads to chronic non-healing wounds and eventually potential amputation of extremities. Here we examine the use of a bioactive angiogenic peptide-based hydrogel, SLan, to improve early wound healing in diabetic rats, and compare its performance to clinically utilized biosynthetic peptide-based materials such as Puramatrix. Streptozotocin-treated diabetic rats underwent 8 mm biopsy wounding in their dorsum to remove the epithelium, adipose tissues and muscle layer of the skin, and served as a model for diabetic wound healing. Wounds were treated with either Low (1w%) SLan, High (4w%) SLan, PBS, Puramatrix or K2 (an unfunctionalized non-bioactive control sequentially similar to SLan), covered with Tegaderm and monitored on days 0, 3, 7, 10, 14, 17, 21, 28; animals were sacrificed for histomorphic analyses and immunostaining. An LC/MS method developed to detect SLan in plasma allows pharmacokinetic analysis showing no trafficking of peptides from the wound site into the circulation. Low and High SLan groups show similar final outcomes of wound contraction as control groups (Puramatrix, PBS and K2). SLan-treated rats, however, show marked improvement in healing in earlier time points, including increased deposition of new mature blood vessels. Additionally, rats in the Low SLan treatment groups showed significantly improved wound contraction over other groups and significantly improved healing in early time points. Altogether our results suggest this material can be used to "jumpstart" the diabetic wound healing process. This article is protected by copyright. All rights reserved.

Overview of in situ gelling injectable hydrogels for diabetic wounds

Diabetes mellitus (DM) is an endocrine disorder that causes increased blood glucose than usual due to insulin impairment. In DM, several complications arise in which diabetic wound (DW) is the most devastating complication. About 25% of patients with DM expected to develop DWs in their lifetime and undergo limb amputations. Even though several treatments such as surgery, debridement, wound dressings, advanced therapies were available, the overall conclusion has been that with very few exceptions, patients still suffer from limitations like pain, frequent dress changing, high rates of failure, and cost involvement. Further, the treatments involving the delivery of therapeutic agents in treating DWs have limited success due to abnormal levels of proteases in the DW environment. In this backdrop, in situ gelling injectable hydrogels have gained special attention due to their easy encapsulation of therapeutic medications and prolonged release, filling the wound defect areas, ease of handling, and minimally invasive surgical procedures. Though the in situ gelling injectable hydrogels are developed a couple of decades ago, their use for treating DW has not yet been explored thoroughly. Thus, in this review, we have covered the sequential events of DW healing, pathophysiology, current treatments, and its limitations, along with a particular emphasis on the mechanism of action of these in situ gelling injectable hydrogels treating DWs.

Sulfated Polysaccharides from Marine Algae as a Basis of Modern Biotechnologies for Creating Wound Dressings: Current Achievements and Future Prospects

Wound healing involves a complex cascade of cellular, molecular, and biochemical responses and signaling processes. It consists of successive interrelated phases, the duration of which depends on a multitude of factors. Wound treatment is a major healthcare issue that can be resolved by the development of effective and affordable wound dressings based on natural materials and biologically active substances. The proper use of modern wound dressings can significantly accelerate wound healing with minimum scar mark. Sulfated polysaccharides from seaweeds, with their unique structures and biological properties, as well as with a high potential to be used in various wound treatment methods, now undoubtedly play a major role in innovative biotechnologies of modern natural interactive dressings. These natural biopolymers are a novel and promising biologically active source for designing wound dressings based on alginates, fucoidans, carrageenans, and ulvans, which serve as active and effective therapeutic tools. The goal of this review is to summarize available information about the modern wound dressing technologies based on seaweed-derived polysaccharides, including those successfully implemented in commercial products, with a focus on promising and innovative designs. Future perspectives for the use of marine-derived biopolymers necessitate summarizing and analyzing results of numerous experiments and clinical trial data, developing a scientifically substantiated approach to wound treatment, and suggesting relevant practical recommendations.

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.

Encapsulation of Satureja khuzistanica extract in alginate hydrogel accelerate wound healing in adult male rats

BACKGROUND

Finding the best dressing for a specific wound had continued from the past to present. The aim of this study was to evaluate the effect of encapsulated extract of Satureja khuzistanica in hydrogel alginate at wound healing.

METHODS

Thirty-two male Wistar rats with a puncture wound in the back of the neck skin were divided randomly into four groups including a control group, Satureja khuzistanica-treated group, hydrogel alginate-treated group, and Satureja khuzistanica encapsulated in hydrogel alginate-treated group. Rats were treated for 22 days. The skin samples were taken on 3rd, 7th, 14th, and 22nd days after treatment for light microscopy. Results were analyzed in accordance with Kruskal-Wallis and Friedman test (for histopathology analysis) by using SPSS v.22 software.

RESULTS

Macroscopically evaluations and measurement of wound size showed increased wound healing process in the treated groups. The complete improvement was created on the 14th day. The wound site was not observed on the 22nd day. But the wound site was observed on the 22nd day in the control group. Also, comparison of the percentage of wound healing between the treated and control groups on 3rd, 7th, 14th, and 22nd days showed a significant difference (p < 0.05). Comparison of the H&E stained sections in the studied groups showed that treated groups were effective on wound healing in comparison with the control group.

CONCLUSIONS

Encapsulated extract of Satureja khuzistanica in hydrogel alginate may accelerate wound improvement and increase the rate of wound healing without scar formation.

Efficacy of a hydroactive colloid gel versus historical controls for the prevention of radiotherapy-induced moist desquamation in breast cancer patients

PURPOSE

Radiotherapy-induced moist desquamation (RIMD) is a complication that can affect patients' quality of life and jeopardize radiotherapy outcomes. The curative use of a hydroactive colloid gel has previously been shown effective in the management of RIMD in breast cancer patients. This study aimed at investigating the efficacy of this same gel but in the prevention of RIMD.

METHODS

A group of breast cancer patients who applied the hydroactive gel from start to end of post-lumpectomy radiotherapy (Preventive Hydrogel group) were compared with two groups of matched historical controls: a group applying a dexpanthenol cream throughout their therapy and a group applying first the dexpanthenol cream then, after 11-14 fractions of radiotherapy, the hydroactive gel (Curative Hydrogel group). All patients received identical fractionation regimen. The clinical outcomes were the incidence and time to onset of RIMD.

KEY RESULTS

After 25 fractions of radiotherapy (50 Gy), patients in the Preventive Hydrogel group (N = 202) developed RIMD significantly less frequently and later than patients in the Dexpanthenol group (N = 131; incidence = 7% vs 35% respectively, odds ratios = 7.27; probability of RIMD-free survival after 50 Gy = 0.88 vs 0.62). There were no significant differences between the Preventive and the Curative Hydrogel group (N = 87).

CONCLUSIONS

These findings confirm our previous results: applying the hydroactive colloid gel, rather than dexpanthenol, delayed the onset and reduced the incidence of RIMD in breast cancer patients. However, applying the hydrogel preventively offered no statistically significant advantages over applying it curatively.

Biomaterials and tissue engineering for scar management in wound care

Scars are a natural and unavoidable result from most wound repair procedures and the body's physiological healing response. However, they scars can cause considerable functional impairment and emotional and social distress. There are different forms of treatments that have been adopted to manage or eliminate scar formation. This review covers the latest research in the past decade on using either natural agents or synthetic biomaterials in treatments for scar reduction.

Antibacterial constituents of Fructus Chebulae Immaturus and their mechanisms of action

Background

To extract, purify, and identify the effective constituents of aqueous extract of Fructus Chebulae Immaturus, and analyze the bactericidal effects of total tannins.

Methods

Preparative thin layer chromatography and semi-preparative high performance liquid chromatography were used to isolate and purify the total tannin fraction. ¹H- and ¹³C- NMR spectroscopy were used to elucidate compound structures. The antibacterial activities of total tannins and ethyl gallate on Klebsiella pneumoniae (KP) and Staphylococcus aureus (SA) were determined through minimum inhibitory concentration and minimum bactericidal concentration assays. Their antibacterial mechanisms of action were explored by transmission electron microscopy and scanning electron microscopy.

Results

Five compounds were isolated: ellagic acid, ethyl gallate, arjugenin, β-sitosterol, and tri-n-butyl chebulate. Tri-n-butyl chebulate is a newly-reported compound. Total tannins and ethyl gallate both had favorable bactericidal effects against KP and SA.

Conclusion

In vivo and in vitro pharmacodynamic experiment demonstrated that the effective components of Fructus Chebulae Immaturus possessed significant antibacterial effects, and were nontoxic and safe.

Trial registration

No results of a health care intervention on human participants

Recent advances on the development of wound dressings for diabetic foot ulcer treatment--a review

Diabetic foot ulcers (DFUs) are a chronic, non-healing complication of diabetes that lead to high hospital costs and, in extreme cases, to amputation. Diabetic neuropathy, peripheral vascular disease, abnormal cellular and cytokine/chemokine activity are among the main factors that hinder diabetic wound repair. DFUs represent a current and important challenge in the development of novel and efficient wound dressings. In general, an ideal wound dressing should provide a moist wound environment, offer protection from secondary infections, remove wound exudate and promote tissue regeneration. However, no existing dressing fulfills all the requirements associated with DFU treatment and the choice of the correct dressing depends on the wound type and stage, injury extension, patient condition and the tissues involved. Currently, there are different types of commercially available wound dressings that can be used for DFU treatment which differ on their application modes, materials, shape and on the methods employed for production. Dressing materials can include natural, modified and synthetic polymers, as well as their mixtures or combinations, processed in the form of films, foams, hydrocolloids and hydrogels. Moreover, wound dressings may be employed as medicated systems, through the delivery of healing enhancers and therapeutic substances (drugs, growth factors, peptides, stem cells and/or other bioactive substances). This work reviews the state of the art and the most recent advances in the development of wound dressings for DFU treatment. Special emphasis is given to systems employing new polymeric biomaterials, and to the latest and innovative therapeutic strategies and delivery approaches.

Current trends in the development of wound dressings, biomaterials and devices

Wound management covers all aspects of patient care from initial injury, treatment of infection, fluid loss, tissue regeneration, wound closure to final scar formation and remodeling. There are many wound-care products available including simple protective layers, hydrogels, metal ion-impregnated dressings and artificial skin substitutes, which facilitate surface closure. This review examines recent developments in wound dressings, biomaterials and devices. Particular attention is focused on the design and manufacture of hydrogel-based dressings, their polymeric constituents and chemical modification. Finally, topical negative pressure and hyperbaric oxygen therapy are considered. Current wound-management strategies can be expensive, time consuming and labor intensive. Progress in the multidisciplinary arena of wound care will address these issues and be of immense benefit to patients, by improving both clinical outcomes and their quality of life.