Wound Healing Dressings Research Articles

Multiple-dynamic-bond crosslinked ion-elastomers achieve a combination of photothermal antibacterial and self-powered electrical stimulation for infected wound healing

Numerous hydrogel dressings have been reported, which can effectively accelerate wound healing with the assistance of photothermal antibacterial therapy and an external electric field. However, these hydrogel dressings face challenges such as water loss during photothermal progress, low temperature intolerance, and difficulties in recycling. Here, we develop a poly lipoic acid (PLA) ion-elastomer that synergistically utilizes photothermal therapy and electrical stimulation from a self-powered PLA triboelectric nanogenerator (TENG) to promote wound healing. The multiple dynamic bonds within the resulted ion-elastomer dressing make them highly stretchable (> 2000%), self-healing, easy to recover, and conductive (0.3 S m−1 at 25 °C). Through a combination of photothermal therapy and real-time electrical stimulation, the PLA ion-elastomer/TENG system can availably promote angiogenesis, collagen deposition, re-epithelialization, and tissue regeneration, thereby accelerating wound healing within a relatively short timeframe (11 days). Moreover, the ion-elastomer exhibits temperature sensitivity (TCR = 6.2% K−1) and human motion perception capabilities. We deem that this work will be conducive to the employment of versatile ion-elastomer dressings in wound healing and the progress in bio-patches with synergistic effects.

Multifunctional Hydrogels Based on γ-Polyglutamic Acid/Polyethyleneimine for Hemostasis and Wound Healing.

Current hemostatic materials have many shortcomings, such as biotoxicity or poor degradability, and do not effectively promote wound healing after hemostasis. To address these limitations, a hemostasis-promoting wound-healing hydrogel, polyglutamic acid/polyethyleneimine/montmorillonite (PPM), comprising polyglutamic acid, 3,4-dihydroxybenzaldehyde-modified polyethyleneimine, and amino-modified montmorillonite (montmorillonite-NH2) was constructed in this study. Due to the excellent water absorption abilities of γ-polyglutamic acid, the PPM and polyglutamic acid/polyethyleneimine hydrogels could rapidly absorb the blood and tissue fluid exuded from the wound to keep the wound clean and accelerate the blood coagulation. The homogeneous distribution of montmorillonite-NH2 enhanced not only the mechanical properties of the hydrogel but also its hemostatic properties. In addition, the modification of polyethylenimine with 3,4-dihydroxybenzaldehyde provided anti-inflammatory effects and endorsed the wound healing. Cellular and blood safety experiments demonstrated the biocompatibility of the PPM hydrogel, and animal studies demonstrated that the PPM hydrogel effectively stopped bleeding and promoted wound healing. The concept design of clay-based hydrogel may create diverse opportunities for constructing hemostasis and wound-healing dressings.

Magneto-responsive biocomposites in wound healing: from characteristics to functions.

The number of patients with non-healing wounds continuously increases, and has become a prominent societal issue that imposes a heavy burden on both patients and the entire healthcare system. Although traditional dressings play an important role in wound healing, the complexity and diversity of the healing process pose serious challenges in this field. Magneto-responsive biocomposites, with their excellent biocompatibility, remote spatiotemporal controllability, and unique convenience, demonstrate enticing advantages in the field of wound dressings. However, current research on magneto-responsive biocomposites as wound dressings lacks comprehensive and in-depth reviews, which to some extent, restricts the deeper understanding and further development of this field. Based on this, this paper reviews the latest advances in magnetic responsive wound dressings for wound healing. First, we review the process of skin wound healing and parameters for assessing repair progress. Then, we systematically discuss the preparation strategies and unique characteristics of magneto-responsive biocomposites, focusing on magneto-induced orientation, magneto-induced mechanical stimulation, and magnetocaloric effect. Subsequently, this review elaborates the multiple mechanisms of magneto-responsive biocomposites in promoting wound healing, including regulating cell behavior, enhancing electrical signal, controlling drug release, and accelerating tissue reconstruction. Finally, we further propose the development direction and future challenges of magnetic responsive biomaterials as wound dressings in clinical application.

Superior rat wound-healing activity of green synthesized silver nanoparticles from acetonitrile extract of Juglans regia L: Pellicle and leaves

The process of wound healing is complicated. Antimicrobial silver has been one of the substances used for wounds since ancient times. Moreover, traditional medicine has long used Juglans regia L. to promote wound healing. Since eco-friendly nanotechnology has various uses in biomedical research, the aim of this study was to assess the wound-healing capacity of bio-reduced silver nanoparticles (AgNPs). UV, DLS, TEM, and FTIR were used to characterize the prepared AgNPs. Pellicle's bioreduced AgNP (AgNP/P) has a better polydispersity index (PI) of 0.336 compared to its chemically synthesized peers, which have a PI of 0.67. Using incision and excision wound healing models, AgNPs and extracts were compared to Solcoseryl®. Skin-breaking strength, wound contraction, epithelialization time, histology, and cytokines were all assessed. Juglans regia L. pellicle extract (P) has shown significant effectiveness in both models, as well as their bio-reduced partner AgNP/P. The skin's tensile strength following AgNP/P therapy (871 g, p value < 0.05) is comparable to that after Solcoseryl® (928 g), both of which are significantly better than AgNP (592 g) in the incision wound model. Epithelialization time (16.0 and 16.5 days) did not substantially differ from Solcoseryl® (15.3 days) (P value < 0.05). There was an elevated collagen content. Low levels of IL1β (189.0 pg/g) and high levels of TNF-α (1007.1 pg/g) in the case of AgNP/P suggest various cellular kinds of maturation and various wound healing structures that are evident in histopathology investigations. The bioreduced AgNP/P could find use as a pharmaceutical agent for wound healing dressings.

Chitosan oligomer/silver nanoparticles/PCL composite electrospun membrane for severe burn wound healing

In the management of burn wounds, antimicrobial and wound healing properties are crucial. In this study, we prepared a three-layer electrospun poly(ε-caprolactone) (PCL) membrane for burn wound dressing. The hydrophobic electrospun PCL layer, embedded with silver nanoparticles (SNPs) (PCL-Ag), was coated with another layer of electrospun plasma-treated PCL-Ag to enhance the wettability of the membrane. This enhancement was to facilitate the absorption of the hydrophilic chitosan oligomer (COS) - the third layer of the dressing. The resultant membranes were characterised and tested for different properties to demonstrate their applicability as wound dressing materials. The combination of COS and SNPs of the fabricated membrane supports the healing process and reduces burn severity due to the healing capacity of COS and the antibacterial activity of SNPs, without compromising mechanical strength. We conducted several in vitro and in vivo experiments to evaluate its applicability for burn wound healing. The PCL-Ag/COS sample demonstrated outstanding in vitro biocompatibility and excellent antibacterial activity against Staphylococcus aureus strains. We used the membrane to treat burns on rabbits in the laboratory over 30 days, and consistently observed positive outcomes. This research offers insights into the development of bioactive dressings for wound healing and opens up opportunities for practical applications of COS-incorporated materials.

Antibacterial conductive self-healing hydrogel wound dressing with dual dynamic bonds promotes infected wound healing.

In clinical applications, there is a lack of wound dressings that combine efficient resistance to drug-resistant bacteria with good self-healing properties. In this study, a series of adhesive self-healing conductive antibacterial hydrogel dressings based on oxidized sodium alginate-grafted dopamine/carboxymethyl chitosan/Fe3+ (OSD/CMC/Fe hydrogel)/polydopamine-encapsulated poly(thiophene-3-acetic acid) (OSD/CMC/Fe/PA hydrogel) were prepared for the repair of infected wound. The Schiff base and Fe3+ coordination bonds of the hydrogel structure are dynamic bonds that can be repaired automatically after the hydrogel network is disrupted. Macroscopically, the hydrogel exhibits self-healing properties, allowing the hydrogel dressing to adapt to complex wound surfaces. The OSD/CMC/Fe/PA hydrogel showed good conductivity and photothermal antibacterial properties under near-infrared (NIR) light irradiation. In addition, the hydrogels exhibit tunable rheological properties, suitable mechanical properties, antioxidant properties, tissue adhesion properties and hemostatic properties. Furthermore, all hydrogel dressings improved wound healing in the infected full-thickness defect skin wound repair test in mice. The wound size repaired by OSD/CMC/Fe/PA3 hydrogel+NIR was much smaller (12%) than the control group treated with Tegaderm™ film after 14 days. In conclusion, the hydrogels have high antibacterial efficiency, suitable conductivity, great self-healing properties, good biocompatibility, hemostasis and antioxidant properties, making them promising candidates for wound healing dressings for the treatment of infected skin wounds.

Microwave‐assisted hydrothermal green synthesis of selenium nanoparticles incorporated with hyaluronic acid methacrylate/gelatin methacrylate hydrogels for wound healing applications

AbstractWound healing is a topic of significant interest in current times, owing to the escalating incidence of chronic diseases associated with impaired healing, as well as the growing number of elderly individuals within the population. Amongst the various approaches for fabrication of wound healing dressings, the utilization of selenium‐based nanoparticles has garnered considerable attention due to selenium's numerous advantages, including antioxidant, antiviral, antibacterial, and antifungal activities. With this perspective, we focused on the fabrication and characterization of hydrogels incorporated with selenium nanoparticles (SeNPs). In this work, we have developed a microwave‐assisted hydrothermal synthesis strategy for synthesis of the SeNPs that employ non‐toxic precursors, thereby reducing the risk of environmental toxicity and providing a cost‐effective alternative to conventional chemical and hydrothermal methods. Subsequently, we have successfully incorporated SeNPs into hyaluronic acid methacrylate/gelatin methacrylate‐based hydrogels. Hyaluronic acid and gelatin are selected to support the healing process further, and these polymers are methacrylated in order to further control mechanical properties of the hydrogel and improve the stability of the dressing. The nanoparticles and the nanoparticle‐incorporated hydrogels were characterized by various techniques including Fourier transform infrared spectroscopy, UV–Vis spectroscopy, scanning electron microscopy, and dynamic light scattering instruments. Mechanical behaviors, swelling and degradation properties of the dressings were evaluated. Afterwards, we have conducted cell culture studies with SeNPs‐loaded hydrogels to determine the efficacy of SeNPs in wound healing. According to experimental findings, in vitro scratch assay suggests that a hydrogel dressing containing SeNPs (HG‐SeNp2) support the cell migration more compared to other samples incorporated with nanoparticles and to the control study at 24 h, and the wound closure percentage was found to be statistically significant compared with the control study. This dressing hold promise as effective wound dressings that can facilitate and expedite the process of wound healing.

Sol-gel derived B2O3-CaO borate bioactive glasses with hemostatic, antibacterial and pro-angiogenic activities.

Sol-gel borate bioactive glasses (BGs) are promising ion-releasing biomaterials for wound healing applications. Here, we report the synthesis of a series of binary B2O3-CaO borate BGs (CaO ranging from 50 to 90 mol%) using a sol-gel-based method. The influence of CaO content in B2O3-CaO borate BG on morphology, structure and ion release behavior was investigated in detail. Reduced dissolution (ion release) and crystallization could be observed in borate BGs when CaO content increased, while the morphology was not significantly altered by increasing CaO content. Our results evidenced that the ion release behavior of borate BGs could be tailored by tuning the B2O3/CaO molar ratio. We also evaluated the in vitro cytotoxicity, hemostatic, antibacterial and angiogenic activities of borate BGs. Cytocompatibility was validated for all borate BGs. However, borate BGs exhibited composition-dependent hemostatic, antibacterial and angiogenic activities. Generally, higher contents of Ca in borate BGs facilitated hemostatic activity, while higher contents of B2O3 were beneficial for pro-angiogenic activity. The synthesized sol-gel-derived borate BGs are promising materials for developing advanced wound healing dressings, given their fast ion release behavior and favorable hemostatic, antibacterial and angiogenic activities.

Plant-Derived Nanocellulose with Antibacterial Activity for Wound Healing Dressing.

The medical sector is one of the biggest consumers of single-use materials, and while the insurance of sterile media is non-negotiable, the environmental aspect is a chronic problem. Nanocellulose (NC) is one of the safest and most promising materials that can be used in medical applications due to its valuable properties like biocompatibility and biodegradability, along with its good mechanical properties and high water uptake capacity. However, NC has no bactericidal activity, which is a critical need for the effective prevention of infections in chronic diabetic wound dressing applications. Therefore, in this work, a natural product, propolis extract (PE), was used as an antibacterial agent, in different amounts, together with NC to obtain sponge-like structures (NC/PE). The scanning electron microscope (SEM) images showed well-impregnated cellulose fibers and a more compact structure with the addition of PE. According to the thermogravimetric analysis (TGA), the samples containing PE underwent thermal degradation before the unmodified NC due to the presence of volatile compounds in the extract. However, the peak degradation temperature in the first derivative thermogravimetric curves was higher for all the sponges containing PE when compared to the unmodified NC. The antibacterial efficacy of the samples was tested against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, as well as on two clinically resistant isolates. The samples completely inhibited the development of Staphylococcus aureus, and Pseudomonas aeruginosa was partially inhibited, while Escherichia coli was resistant to the PE action. Considering the physical and biological properties along with the environmental and economic benefits, the development of an NC/PE wound dressing seems promising.

Clay Therapy in Wound Healing: A Brief Review of the Literature

Clay is ubiquitous, and its hydrous phyllosilicate properties have promoted its use as a traditional wound healing agent in many cultures. Various types of natural clay have been utilized for skin diseases and wound treatments. Therefore, we aimed to study natural and synthetic clay minerals and summarize their applicability in medical settings. A review of prospective studies published since 2008 examining the properties of different forms of natural clay minerals and their therapeutic benefits in wound care was conducted. Studies were obtained using the databases of Google Scholar, PubMed, Web of Science, and HINARI (Health Inter-Network Access to Research Initiative) and searching related journals. The primary outcomes were assessed qualitatively and were categorized by the type of natural clay used. The included papers studied five available types of clay: Chamliyal clay, French green clay, Oregon Mineral Technologies blue clay, Kisameet clay, and various synthetic clays. The studies found how these forms of clay together demonstrate anti-inflammatory and antibacterial properties while promoting fibroblast regeneration and circulation while remaining biocompatible. Clay-based materials may be a potential alternative for conventional dressings for wound healing in resource-limited settings. This review opens doors to expanding clay-based therapies for wound healing.

Wide Local Excision of Complex or Infected Pilonidal Sinus Followed by Negative Pressure Wound Therapy: Does It Enhance Wound Healing?

Background Pilonidal sinus disease (PSD) is a chronic skin condition caused by hair retention that affects the sacrococcygeal cleft. The purpose of this study is to compare the efficacy of negative pressure wound therapy (NPWT) to routine daily dressings (DDs) in wound healing after complex or infected pilonidal sinus tract excision. Materials and methods The study included 81 individuals who had extensive local excisions for pilonidal sinuses that were complex or infected. Randomly selected participants were given either NPWT or the usual dressing. Between the two groups, the length of hospitalization, the amount of time needed to resume daily activities, and the amount of time needed for full wound closure were compared. Results Forty-two patients received NPWT, while 39 patients received DDs as usual. There was no discernible difference between the two groups in terms of operating time or hospital stay. However, patients who underwent NPWT experienced a quicker final wound closure (59.24 ± 10.21 days compared to routine DD with a mean time of 75.31 ± 14.68 days, P = 0.001) and returned to normal activities earlier (17.36 versus 21.75 days in NPWT and routine DD, respectively). Conclusion Compared to patients who received standard DDs, those who were postoperatively managed with NPWT showed faster wound healing and return to normal activities. Whenever feasible, this strategy may be employed to improve patient recovery.

Hydrogels dressings based on guar gum and chitosan: Inherent action against resistant bacteria and fast wound closure

Hydrogels made with depolymerized guar gum, oxidized with theoretical oxidation degrees of 20, 35 and 50 %, were obtained via Schiff's base reaction with N-succinyl chitosan. The materials obtained were subjected to characterization by FT-IR, rheology, swelling, degradation, and morphology. Additionally, their gelation time categorized all three hydrogels as injectable. The materials' swelling degrees in Phosphate-Buffered Saline (PBS) were in the range of 26–35 g of fluid/g gel and their pore size distribution was heterogeneous, with pores varying from 67 to 93 μm. All hydrogels degraded in PBS solution, but maintained around 40 % of their initial mass after 28 days, which was more than enough time for wound healing. The biomaterials were also flexible, self-repairing, adhesive and cytocompatible and presented intrinsic actions, regardless of the presence of additives or antibiotics, against gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and gram-negative bacteria (Escherichia coli). However, the most pronounced bactericidal effect was against resistant Staphylococcus aureus - MRSA. In vivo assays, performed with 50 % oxidized gum gel, demonstrated that this material exerted anti-inflammatory effects, accelerating the healing process and restoring tissues by approximately 99 % within 14 days. In conclusion, these hydrogels have unique characteristics, making them excellent candidates for wound-healing dressings.

An injectable and light curable hyaluronic acid composite gel with anti-biofilm, anti-inflammatory and pro-healing characteristics for accelerating infected wound healing

Bacterial biofilm formation and drug resistance are common issues associated with wound healing. Antimicrobial peptides (AMPs) are a new class of antimicrobial agents with the potential to solve these global health issues. New injectable adhesive antibacterial hydrogels have excellent prospects of becoming the next innovative wound-healing dressings. In this study, the hyaluronic acid was connected to the antibacterial peptide Plantaricin 149 (Pln149), obtaining HAD@AMP. HAD@AMP performed well in efficient antimicrobial activity, good histocompatibility, low drug resistance, low bacterial biofilm formation, and fast wound healing process which are essential for rapid healing of infected wound. During the hydrogel degradation process, Pln149 was released to inhibit bacterial communication and reduce bacterial biofilm formation. Meanwhile, HAD@AMP could up-regulate anti-inflammatory and pro-angiogenic factors, and down-regulate inflammatory factors to promote the healing of infected wounds, which provide a new idea for skin healing strategies.

Functional Microneedle Patch for Wound Healing and Biological Diagnosis and Treatment.

Wound healing, especially chronic wounds, has been one of the major challenges in the field of biomedicine. Drug therapy alone is not effective, so a variety of functional wound healing dressings have been developed. Microneedles have attracted more and more attentions in the field of wound healing dressings due to their penetration and high drug delivery efficiency. In this review, all the studies on the application of microneedles in wound healing in recent years are summarized, classify different microneedles according to their functions in the process of wound healing, discuss the current challenges in the transformation of microneedle technology toward clinical applications, and finally look forward to the future design and development directions of microneedles in this field.

Functionalization of bioactive moringa gum for designing hydrogel wound dressings

In view of wound healing properties of moringa gum (MG) and the antibacterial activity of poly(METAC), in the present work, the antibiotic drug ofloxacin encapsulated MG-cl-poly(METAC) based hydrogel dressings were prepared by graft copolymerization reaction for better wound care. Network copolymeric structure was assessed by FESEM, AFM, EDX, 13C NMR, XRD, FTIR and DSC techniques. Swelling properties demonstrated that the network density of hydrogel dressings could be tailored as per the need of wound fluid sorption by controlling feed monomer and crosslinker content during synthesis. FESEM, AFM and XRD revealed a heterogeneous morphology of hydrogels with a rough surface and an amorphous patterns of polymeric materials. Diffusion of ofloxacin from dressing occurred by a non-Fickian diffusion mechanism in simulated wound fluid and was fitted best in First-order kinetic model. Wound dressings exhibited non-haemolytic (0.97% haemolytic potential), mucoadhesive (109.00 ± 4.00 mN peak detachment force) and antioxidant (92.94 ± 2.13% scavenging in DPPH assay) characteristics along with mechanical strength against external stress and strain. Hydrogel dressings were found to be permeable to H2O/O2 and impermeable to microbes. The synergic action of the drug and matrix with antibacterial activity can improve the wound-healing potential of the dressings. These physiological and biomedical properties pointed out the ideal character of moringa gum dressings for better wound healing.

Design and evaluation of moringa gum-based hydrogel dressings for cutaneous wound healing

The study aimed to evaluate moringa gum (MG) and carboxymethyl moringa (CMG) for their possible use in hydrogel-based dressings to treat cutaneous wounds. Initially, MG was characterized for its physical, functional, morphological, and thermal properties. The MG and CMG have shown limited toxicity as indicated by hemolytic assay where values were less than 2.5%. Furthermore, these samples also showed antimicrobial potential. The antioxidant potential of MG was slightly greater than its carboxymethyl derivative. Afterward, MG and CMG were encapsulated in sodium alginate-based hydrogel films. These films showed good physical attributes necessary for the end application. These films were tested in an open wound model in rats. The MG containing films showed the highest % wound contraction on the 10th day, that is,79.42 ± 0.46 with low levels of IL6 and TNF alfa. Out of MG and CMG films, the native moringa gum-based thin film showed comparatively higher potential for wound healing and in the future could be a potential candidate for wound healing dressings.

Switchable hydrophilic/hydrophobic antibacterial fibrous composites for biomedical application

In this study, novel pH responsive hydrophilic/hydrophobic breathable Janus fibrous composites were fabricated with N-halamine quaternary ammonium salt/polyhydroxybutyrate inside and pH sensitive polymer/polycaprolactone outside. After HCl treatment, the fibrous membrane shows well hydrophilicity and breathability, which is helpful for cell growth and proliferation, further accelerating wound healing. Moreover, the membrane has prominent antibacterial efficiencies, which can activate 99.95% of S. aureus and 99.99% of E. coli O157:H7 within 30 min. Notably, this membrane displays excellent hemostasis performance. After further NH4OH treatment, the membrane transforms different wettability and thus reduce bacterial adhesion by its hydrophobicity. Similarly, one side of membrane has hemostasis property, while another side possesses anticoagulant properties with high contact angle of blood, which can prevent blood permeate. Besides, the cell viability test illustrates that no pronounced toxicity to cells is observed. Therefore, the adjustable hydrophilic/hydrophobic material highly extends the application of Janus membrane as wound healing dressing.

Design of polysaccharide gum based network copolymeric hydrogels for drug delivery and wound dressing applications

This article deals with the exploration of the design of network crosslinked structure by covalent bonding for use as wound dressing materials keeping in view inherent therapeutic role of neem gum in wound healing. These copolymeric hydrogels were prepared by graft-copolymerization reaction of carbopol and poly (N-vinylpyrrolidone) (poly (NVP). Antibiotic drug levofloxacin was encapsulated in dressings for better wound healing. The scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, 13C nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal gravimetry (DTG), and differential scanning calorimetry (DSC) techniques were applied for characterization. NMR and FTIR demonstrated incorporation of carbapol and poly (NVP) in dressings. XRD indicated amorphous state in copolymeric dressings. Interactions of copolymers with drug, blood and bio membrane were studied to evaluate biomedical properties which revealed controlled release of drug from hydrogel dressings which were possessing blood-compatible (haemolytic value ​= ​2.45 ​± ​0.82) and mucoadhesive (detachment force ​= ​124 ​± ​41 ​mN) properties. Dressings were permeable to O2 and H2O vapour and absorbed 6.68 ​± ​0.62 ​g/g wound fluid which is ideal dressing characteristic. Diffusion mechanism type of drug levofloxacin was Fickian with kinetic model First order. These properties suggested use of hydrogel material for wound dressing and drug delivery applications for better wound care management.

Iron Nanoparticles Open Up New Directions for Promoting Healing in Chronic Wounds in the Context of Bacterial Infection.

Metal nanoparticles play an outstanding role in the field of wound healing due to their excellent properties, and the significance of iron, one of the most widely used metals globally, cannot be overlooked. The purpose of this review is to determine the importance of iron nanoparticles in wound-healing dressings. Prolonged, poorly healing wounds may induce infections; wound infections are a major cause of chronic wound formation. The primary components of iron nanoparticles are iron oxide nanoparticles, which promote wound healing by being antibacterial, releasing metal ions, and overcoming bacterial resistance. The diameter of iron oxide nanoparticles typically ranges between 1 and 100 nm. Magnetic nanoparticles with a diameter of less than 30 nm are superparamagnetic and are referred to as superparamagnetic iron oxide nanoparticles. This subset of iron oxide nanoparticles can use an external magnetic field for novel functions such as magnetization and functionalization. Iron nanoparticles can serve clinical purposes not only to enhance wound healing through the aforementioned means but also to ameliorate anemia and glucose irregularities, capitalizing on iron's properties. Iron nanoparticles positively impact the healing process of chronic wounds, potentially extending beyond wound management.

In vitro prevention and inactivation of biofilms using controlled-release iodine foam dressings for wound healing.

Microbial biofilms are a major hindrance in the wound healing process, prolonging the inflammatory response phase, thus making them a target in treatment. The aim of this study is to assess the antibacterial properties of commercially available wound dressings, of various material composition and antibacterial agents, towards multiple in vitro microbial and biofilm models. A variety of in vitro microbial and biofilm models were utilised to evaluate the ability of wound dressing materials to sequester microbes, prevent dissemination and manage bioburden. Sequestering and dissemination models were used to evaluate the ability of wound dressing materials to prevent the biofilm-forming bacterium, Pseudomonas aeruginosa, from migrating through dressing materials over a 24-72 h challenge period. Additionally, Centre for Disease Control (CDC) Bioreactor and Drip Flow models were used to evaluate antibacterial killing efficacy towards established P. aeruginosa and Staphylococcus aureus biofilms using more challenging, wound-like models. Controlled-release iodine foam and silver-impregnated carboxymethylcellulose (CMC) wound dressing materials demonstrated potent biofilm management properties in comparison to a methylene blue and gentian violet-containing foam dressing. Both the iodine-containing foam and silver-impregnated CMC materials effectively prevented viable P. aeruginosa dissemination for up to 72 h. In addition, the controlled-release iodine foam and silver-impregnated CMC materials reduced P. aeruginosa bioburden in the Drip Flow model. The controlled-release iodine foam demonstrated superiority in the CDC Bioreactor model, as both the silver- and iodine-containing materials reduced S. aureus to the limit of detection, but P. aeruginosa growth was only completely reduced by controlled-release iodine foam dressing materials. The data generated within the in vitro biofilm models supports the clinical data available in the public domain for the implementation of iodine foam dressings for effective biofilm management and control in wound care.