Use of a hydrogel dressing for management of a painful leg ulcer

Advances in ionic liquid-based antimicrobial wound healing platforms

Wound infections, marked by the proliferation of microorganisms at surgical sites, necessitate the development of innovative wound dressings with potent bactericidal properties to curb microbial growth and prevent bacterial infiltration. This study explores the recent strides in utilizing ionic liquid-based polymers as highly promising antimicrobial agents for advanced wound healing applications. Specifically, cationic polymers containing quaternary ammonium, imidazolium, guanidinium, pyridinium, triazolium, or phosphonium groups have emerged as exceptionally effective antimicrobial compounds. Their mechanism of action involves disrupting bacterial membranes, thereby preventing the development of resistance and minimizing toxicity to mammalian cells. This comprehensive review not only elucidates the intricate dynamics of the skin's immune response and the various stages of wound healing but also delves into the synthesis methodologies of ionic liquid-based polymers. By spotlighting the practical applications of antimicrobial wound dressings, particularly those incorporating ionic liquid-based materials, this review aims to lay the groundwork for future research endeavors in this burgeoning field. Through a nuanced examination of these advancements, this article seeks to contribute to the ongoing progress in developing cutting-edge wound healing platforms that can effectively address the challenges posed by microbial infections in surgical wounds.

The Use of Hydrogel Dressings in Sulfur Mustard-Induced Skin and Ocular Wound Management

Over one century after its first military use on the battlefield, sulfur mustard (SM) remains a threatening agent. Due to the absence of an antidote and specific treatment, the management of SM-induced lesions, particularly on the skin and eyes, still represents a challenge. Current therapeutic management is mainly limited to symptomatic and supportive care, pain relief, and prevention of infectious complications. New strategies are needed to accelerate healing and optimize the repair of the function and appearance of damaged tissues. Hydrogels have been shown to be suitable for healing severe burn wounds. Because the same gravity of lesions is observed in SM victims, hydrogels could be relevant dressings to improve wound healing of SM-induced skin and ocular injuries. In this article, we review how hydrogel dressings may be beneficial for improving the wound healing of SM-induced injuries, with special emphasis placed on their suitability as drug delivery devices on SM-induced skin and ocular lesions.

EHO-85: A Multifunctional Amorphous Hydrogel for Wound Healing Containing Olea europaea Leaf Extract: Effects on Wound Microenvironment and Preclinical Evaluation

The prevalence of chronic wounds is increasing due to the population aging and associated pathologies, such as diabetes. These ulcers have an important socio-economic impact. Thus, it is necessary to design new products for their treatment with an adequate cost/effectiveness ratio. Among these products are amorphous hydrogels. Their composition can be manipulated to provide a favorable environment for ulcer healing. The aim of this study was to evaluate a novel multifunctional amorphous hydrogel (EHO-85), containing Olea europaea leaf extract, designed to enhance the wound healing process. For this purpose, its moistening ability, antioxidant capacity, effect on pH in the wound bed of experimental rats, and the effect on wound healing in a murine model of impaired wound healing were assessed. EHO-85 proved to be a remarkable moisturizer and its application in a rat skin wound model showed a significant antioxidant effect, decreasing lipid peroxidation in the wound bed. EHO-85 also decreased the pH of the ulcer bed from day 1. In addition, in mice (BKS. Cg-m +/+ Leprdb) EHO-85 treatment showed superior wound healing rates compared to hydrocolloid dressing. In conclusion, EHO-85 can speed up the closure of hard-to-heal wounds due to its multifunctional properties that are able to modulate the wound microenvironment, mainly through its remarkable effect on reactive oxygen species, pH, and moistening regulation.

Physico-mechanical Characterization of Liquid versus Solid Applications of Visible Light Cross-Linked Tissue Sealants

The limitations of commercially available tissue sealants have resulted in the need for a new tissue adhesives with adequate adhesion, improved mechanical properties, and innocuous degradation products. To address current limitations, a visible light cross-linking method for the preparation of hydrogel tissue sealants, based on natural polymers (chitosan or alginate), is presented. Water-soluble chitosan was generated via modification with vinyl groups. To form hydrogels, alginate and chitosan were cross-linked by green light illumination, with or without the use of a bifunctional cross-linker. Evaluation of the mechanical properties through rheological characterization demonstrated an increased viscosity of polymer blends, and differences in shear moduli despite similar gelation points upon photo-cross-linking. A comparative study on the burst pressure properties of liquid versus solid material applications was performed to determine if the tissue sealants can perform under physiological lung pressures and beyond using different application methods. Higher burst pressure values were obtained for the sealants applied as a liquid compared to the solid application. The hydrogel tissue sealants revealed no cytotoxic effects toward primary human mesenchymal stem cells. This is the first report of a direct comparison between hydrogel tissue sealants of the same formulation applied in liquid versus solid form.

Biomaterials and Advanced Technologies for Hemostatic Management of Bleeding

Bleeding complications arising from trauma, surgery, and as congenital, disease-associated, or drug-induced blood disorders can cause significant morbidities and mortalities in civilian and military populations. Therefore, stoppage of bleeding (hemostasis) is of paramount clinical significance in prophylactic, surgical, and emergency scenarios. For externally accessible injuries, a variety of natural and synthetic biomaterials have undergone robust research, leading to hemostatic technologies including glues, bandages, tamponades, tourniquets, dressings, and procoagulant powders. In contrast, treatment of internal noncompressible hemorrhage still heavily depends on transfusion of whole blood or blood's hemostatic components (platelets, fibrinogen, and coagulation factors). Transfusion of platelets poses significant challenges of limited availability, high cost, contamination risks, short shelf-life, low portability, performance variability, and immunological side effects, while use of fibrinogen or coagulation factors provides only partial mechanisms for hemostasis. With such considerations, significant interdisciplinary research endeavors have been focused on developing materials and technologies that can be manufactured conveniently, sterilized to minimize contamination and enhance shelf-life, and administered intravenously to mimic, leverage, and amplify physiological hemostatic mechanisms. Here, a comprehensive review regarding the various topical, intracavitary, and intravenous hemostatic technologies in terms of materials, mechanisms, and state-of-art is provided, and challenges and opportunities to help advancement of the field are discussed.

Biomedical applications of soy protein: A brief overview

Soy protein (SP) based materials are gaining increasing interest for biomedical applications because of their tailorable biodegradability, abundance, being relatively inexpensive, exhibiting low immunogenicity, and for being structurally similar to components of the extracellular matrix (ECM) of tissues. Analysis of the available literature indicates that soy protein can be fabricated into different shapes, being relatively easy to be processed by solvent or melt based techniques. Furthermore soy protein can be blended with other synthetic and natural polymers and with inorganic materials to improve the mechanical properties and the bioactive behavior for several demands. This review discusses succinctly the biomedical applications of SP based materials focusing on processing methods, properties and applications highlighting future avenues for research.

Clinical and Antibiofilm Efficacy of Antimicrobial Hydrogels

Significance: Hydrogels have been shown to have a significant role to play in wound healing. Hydrogels are used to assist in the management of dry, sloughy, or necrotic wounds. However, recent scientific evidence has shown that biofilms delay wound healing and increase a wound propensity to infection. It is therefore essential that hydrogels incorporating antimicrobials demonstrate efficacy on biofilms. Consequently, it is the aim of this article to review the efficacy of hydrogels, incorporating antimicrobials, on wounds with specific reference to their efficacy on biofilms. Recent Advances: Technologies being developed for the management of wounds are rapidly expanding. In particularly next-generation hydrogels, incorporating copolymers, have been reported to enable the smart release of antimicrobials. This has led to the development of a more tailored patient-specific antimicrobial hydrogel therapy. Critical Issues: Evidence relating to the efficacy of hydrogels, incorporating antimicrobials, on biofilms within both the in vitro and in vivo environments is lacking. Future Direction: Studies that investigate the efficacy of antimicrobial hydrogel wound dressings on both in vivo and in vitro biofilms are important. However, there is a significant need for better and more reproducible in vivo biofilm models. Until this is possible, data generated from appropriate and representative in vitro models will help to assist researchers and clinicians in evaluating antimicrobial and antibiofilm hydrogel technology for the extrapolation of efficacy data relevant to biofilms present in the in vivo environment.

Therapeutic application of injectable thermosensitive hydrogel in preventing local breast cancer recurrence and improving incision wound healing in a mouse model

Many drug delivery systems (DDSs) have been investigated for local targeting of malignant disease with the intention of increasing anti-tumor activity and minimizing systemic toxicity. An injectable thermosensitive hydrogel was applied to prevent locoregional recurrence of 4T1 breast cancer in a mouse model. The presented hydrogel, which is based on poly(ethyleneglycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE), flows freely at normal temperature, forms a gel within seconds in situ at body temperature, and eventually releases the drug in a consistent and sustained fashion as it gradually biodegrades. Locoregional recurrence after primary tumor removal was significantly inhibited in mice treated with the paclitaxel (PTX)-loaded PECE hydrogel subcutaneously (9.1%) administered, compared with the blank hydrogel (80.0%), systemic (77.8%) and locally (75.0%) administered PTX, and the control group (100%) (P < 0.01). In addition, tensile strength measurements of the surgical incisions showed that the PECE hydrogel accelerates wound healing at postoperative day 7 (P < 0.05), and days 4 and 14 (P > 0.05), in agreement with histopathological examinations. This novel DDSs represents a promising approach for local adjuvant therapy in malignant disease.

Wound healing dressings and drug delivery systems: a review

The variety of wound types has resulted in a wide range of wound dressings with new products frequently introduced to target different aspects of the wound healing process. The ideal dressing should achieve rapid healing at reasonable cost with minimal inconvenience to the patient. This article offers a review of the common wound management dressings and emerging technologies for achieving improved wound healing. It also reviews many of the dressings and novel polymers used for the delivery of drugs to acute, chronic and other types of wound. These include hydrocolloids, alginates, hydrogels, polyurethane, collagen, chitosan, pectin and hyaluronic acid. There is also a brief section on the use of biological polymers as tissue engineered scaffolds and skin grafts. Pharmacological agents such as antibiotics, vitamins, minerals, growth factors and other wound healing accelerators that take active part in the healing process are discussed. Direct delivery of these agents to the wound site is desirable, particularly when systemic delivery could cause organ damage due to toxicological concerns associated with the preferred agents. This review concerns the requirement for formulations with improved properties for effective and accurate delivery of the required therapeutic agents. General formulation approaches towards achieving optimum physical properties and controlled delivery characteristics for an active wound healing dosage form are also considered briefly.

Clinical and microbiological efficacy of MDT in the treatment of diabetic foot ulcers

OBJECTIVE

To assess the clinical and microbiological efficacy of maggot debridement therapy (MDT) in the management of diabetic foot ulcers unresponsive to conventional treatment and surgical intervention.

METHOD

Consecutive diabetic patients with foot wounds presenting at the vascular surgery unit and the diabetic foot unit of Alexandria Main University Hospital were selected for MDT. Lucilia sericata medicinal maggots were applied to the ulcers for three days per week. Changes in the percentage of necrotic tissue and ulcer surface area were recorded each week over the 12-week follow-up period. Semiquantitative swab technique was used to determine the bacterial load before and after MDT.

RESULTS

The sample comprised 10 patients with 13 diabetic foot ulcers. The mean baseline ulcer surface area was 23.5cm2 (range 1.3-63.1), and the mean percentage of necrotic tissue was 74.9% (range 29.9-100). Complete debridement was achieved in all ulcers in a mean of 1.9 weeks (range 1-4). Five ulcers (38.5%) were completely debrided with one three-day MDT cycle. The mean reduction in ulcer size was significant at 90.2%, and this occurred in a mean of 8.1 weeks (range 2-12). The mean weekly reduction in ulcer size was 16.1% (range 8.3-50). Full wound healing occurred in 11 ulcers (84.6%) within a mean of 7.3 weeks (range 2-10). The bacterial load of all ulcers reduced sharply after the first MDT cycle to below the 10(5) threshold, which facilitates healing.

CONCLUSION

The results highlight the potential benefits of MDT in diabetic wound care in developing countries. MDT was proved to be a rapid, simple and efficient method of treating these ulcers.