Moisture Dressings: The New Standard in Wound Care

Comparison of Hydrocolloid Dressings and Silver Nanoparticles in Treatment of Pressure Ulcers in Patients with Spinal Cord Injuries: A Randomized Clinical Trial

Introduction: There are numerous dressings used to treat pressure ulcers (PUs), depending on their advantages to achieve optimum patient outcomes. This study aimed to compare hydrocolloid dressings and silver nanoparticles in treating PUs among patients with spinal cord injury (SCI).

Methods: This randomized clinical trial was conducted on 70 patients with SCI in Iran. Participants were randomly divided into two equal groups (n=35) receiving silver nanoparticle dressing and hydrocolloid dressing, respectively. The groups were evaluated in four assessment periods using the Bates-Jensen Wound Assessment Tool (BWAT). Data analysis was performed using SPSS software version 13, repeated measures ANOVA, non-parametric tests, and chi-square.

Results: Chi-square test was used to investigate the difference between the scores before the intervention, the results of which were not statistically significant. In repetitive measurements, the results of the analysis of variance showed that the average assessment score in both groups decreased and both dressings were effective in the treatment process. Although PU improvement status in the group that received silver nanoparticles was better, between-group analysis of variance did not show any statistically significant difference between the two groups.

Conclusion: Our results indicated that silver nanoparticles and hydrocolloid dressings can be used interchangeably in the treatment of PUs.

Polyanionic Composite Membranes Based on Bacterial Cellulose and Amino Acid for Antimicrobial Application

Ideal wound dressing materials should be active components in the healing process. Bacterial cellulose (BC) has attracted a great deal of attention as novel wound dressing materials; however, it has no intrinsic antimicrobial activity. To explore the practical application values of BC and develop novel wound dressing materials, a series of composite membranes based on BC and polymeric ionic liquids (BC/PILs, composed of BC, and PILs formed by choline and different amino acids) with antimicrobial activity were synthesized by an ex situ method. The physicochemical and antimicrobial properties and biocompatibility of these membranes were systematically investigated. The results indicated that BC/PIL membranes with excellent properties could be obtained by adjusting the concentration and type of PILs. Several kinds of BC/PIL membranes exhibited good biocompatibility and high antimicrobial activity against Gram-positive and Gram-negative bacteria and fungus. The anionic PILs played important roles in the antimicrobial activity of BC/PIL membranes. The obtained membranes provided a novel promising candidate for wound dressing materials.

An extracellular matrix graft (Oasis® wound matrix) for treating full-thickness pressure ulcers: A randomized clinical trial

AIM

The purpose of the study was to evaluate clinical safety and effectiveness of Oasis^® Wound Matrix as a treatment for full-thickness pressure ulcers and compare it to Standard Care.

METHODS

A total of 130 adults with Stage III or Stage IV pressure ulcers were randomly assigned, received either multiple topical treatments of SIS plus standard care (n = 67), or standard care alone (n = 63), and were subsequently evaluated. Ulcer size was determined at enrollment and weekly throughout treatment. Healing was assessed at each visit for a period of up to 12 weeks, with incidence of complete healing and 90% reduction in ulcer area being the primary outcome measures.

RESULTS

The proportion of complete healing in the SIS group was 40% as compared to 29% in the standard of care group (p = 0.111); the percentage of patients having a 90% reduction in ulcer surface area was 55% in the SIS group versus 38% in the standard of care group (p = 0.037).

CONCLUSIONS

The results of this study suggest that within the setting of a comprehensive wound care program, weekly treatment of chronic pressure ulcers with SIS wound matrix increases the incidence of 90% reduction in wound size versus standard of care alone.

Poly(ethylene glycol)-Based Hyperbranched Polymer from RAFT and Its Application as a Silver-Sulfadiazine-Loaded Antibacterial Hydrogel in Wound Care

A multifunctional branched copolymer was synthesized by Reversible Addition-Fragmentation Chain Transfer polymerization (RAFT) of poly(ethylene glycol) diacrylate (PEGDA M_n = 575) and poly(ethylene glycol) methyl methacrylate (PEGMEMA M_n = 500) at a feed molar ratio of 50:50. Proton nuclear magnetic resonance spectroscopy (¹H NMR) confirmed a hyperbranched molecular structure and a high degree of vinyl functionality. An in situ cross-linkable hydrogel system was generated via a "click" thiol-ene-type Michael addition reaction of vinyl functional groups from this PEGDA/PEGMEMA copolymer system in combination with thiol-modified hyaluronic acid. Furthermore, encapsulation of antimicrobial silver sulfadiazine (SSD) into the copolymer system was conducted to create an advanced antimicrobial wound care dressing. This hydrogel demonstrated a sustained antibacterial activity against the bacterial strains Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli in comparison to the direct topical application of SSD. In addition, in vitro toxicology evaluations demonstrated that this hydrogel-with low concentrations of encapsulated SSD-supported the survival of embedded human adipose derived stem cells (hADSCs) and inhibited growth of the aforementioned pathogens. Here we demonstrate that this hydrogel encapsulated with a low concentration (1.0% w/v) of SSD can be utilized as a carrier system for stem cells with the ability to inhibit growth of pathogens and without adverse effects on hADSCs.

In Vitro Evaluation and Mechanism Analysis of the Fiber Shedding Property of Textile Pile Debridement Materials

Fiber shedding is a critical problem in biomedical textile debridement materials, which leads to infection and impairs wound healing. In this work, single fiber pull-out test was proposed as an in vitro evaluation for the fiber shedding property of a textile pile debridement material. Samples with different structural design (pile densities, numbers of ground yarns and coating times) were prepared and estimated under this testing method. Results show that single fiber pull-out test offers an appropriate in vitro evaluation for the fiber shedding property of textile pile debridement materials. Pull-out force for samples without back-coating exhibited a slight escalating trend with the supplement in pile density and number of ground yarn plies, while back-coating process significantly raised the single fiber pull-out force. For fiber shedding mechanism analysis, typical pull-out behavior and failure modes of the single fiber pull-out test were analyzed in detail. Three failure modes were found in this study, i.e., fiber slippage, coating point rupture and fiber breakage. In summary, to obtain samples with desirable fiber shedding property, fabric structural design, preparation process and raw materials selection should be taken into full consideration.

A flexible and low power telemetric sensing and monitoring system for chronic wound diagnostics

BACKGROUND

Non-healing chronic wounds, such as venous leg ulcers, can be monitored non-invasively by using modern sensing devices and wireless technologies. The development of such a wireless diagnostic tool may improve chronic wound management by providing evidence on efficacy of treatments being provided. This paper presents a low-power portable telemetric system for wound condition sensing and monitoring. The system aims at measuring and transmitting real-time information of wound-site temperature, sub-bandage pressure and moisture level from within the wound dressing.

METHODS

Commercially available non-invasive temperature, moisture, and pressure sensors are interfaced with a telemetry device on a flexible 0.15 mm thick printed circuit material to construct a light-weight, non-invasive, biocompatible, and low-power sensing device. The real-time data obtained is transmitted wirelessly to a portable receiver which displays the measured values. The performance of the whole telemetric sensing system is validated on a mannequin leg using commercial compression bandages and dressings. A number of trials on a healthy human volunteer are performed where treatment conditions were emulated using various compression bandage configurations.

RESULTS

A reliable and repeatable performance of the system is achieved under compression bandage and with minimal discomfort to the volunteer. The system is capable of reporting instantaneous changes in bandage pressure, moisture level and local temperature at wound site with average measurement resolutions of 0.5 mmHg, 3.0% RH, and 0.2°C respectively. Effective range of data transmission is 4-5 m in an open environment.

CONCLUSIONS

A flexible and non-invasive sensing system is developed to acquire and wirelessly transmit wound parameters from within a compression bandage and wound dressing worn on a human limb. Pre-clinical results on a healthy human subject suggest its clinical usability and value to health practitioners. However, further performance evaluations of the device on a wider population of healthy human subjects and on patients with chronic wounds are required to confirm its medial usefulness and to quantify its real impact on chronic wound management.

Chitosan-based electrospun nanofibrous mats, hydrogels and cast films: novel anti-bacterial wound dressing matrices

The development of highly efficient anti-bacterial wound dressings was carried out. For this purpose nanofibrous mats, hydrogels and films were synthesized from chitosan, poly(vinyl alcohol) and hydroxyapatite. The physical/chemical interactions of the synthesized materials were evaluated by FTIR. The morphology, structure; average diameter and pore size of the materials were investigated by scanning electron microscopy. The hydrogels showed a greater degree of swelling as compared to nanofibrous mats and films in phosphate buffer saline solution of pH 7.4. The in vitro drug release studies showed a burst release during the initial period of 4 h and then a sustained release profile was observed in the next upcoming 20 h. The lyophilized hydrogels showed a more slow release as compared to nanofibrous mats and films. Antibacterial potential of drug released solutions collected after 24 h of time interval was determined and all composite matrices showed good to moderate activity against Gram-positive and Gram-negative bacterial strains respectively. To determine the cytotoxicity, cell culture was performed for various cefixime loaded substrates by using neutral red dye uptake assay and all the matrices were found to be non-toxic.

Carboxymethyl cellulose wafers containing antimicrobials: a modern drug delivery system for wound infections

Lyophilised wafers have been shown to have potential as a modern dressing for mucosal wound healing. The wafer absorbs wound exudates and transforms into a gel, thus providing a moist environment which is essential for wound healing. The objective of this study was to develop a carboxymethyl cellulose wafer containing antimicrobials to promote wound healing and treat wound infection. The pre-formulation studies began with four polymers, sodium carboxymethyl cellulose (NaCMC), methylcellulose (MC), sodium alginate and xanthan gum, but only NaCMC and MC were chosen for further investigation. The wafers were characterised by physical assessments, solvent loss, microscopic examination, swelling and hydration properties, drug content uniformity, drug release and efficacy of antimicrobials. Three of the antimicrobials, neomycin trisulphate salt hydrate, sulphacetamide sodium and silver nitrate, were selected as model drugs. Among the formulations, NaCMC wafer containing neomycin trisulphate exhibited the most desirable wound dressing characteristics (i.e., flexibility, sponginess, uniform wafer texture, high content drug uniformity) with the highest in vitro drug release and the greatest inhibition against both Gram positive and Gram negative bacteria. In conclusion, we successfully developed a NaCMC lyophilised wafer containing antimicrobials, and this formulation has potential for use in mucosal wounds infected with bacteria.

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.

BACTERIAL CELLULOSE: A NATURAL NANOMATERIAL FOR BIOMEDICAL APPLICATIONS

Bacterial cellulose (BC) synthesized from Acetobacter xylinum has drawn lots of attention and interest from biomedical device field due to its unique structure and properties. Characterized by its remarkable physical strength and extremely hydrophilic surface, BC has become a favorable material for wound healing, neuron protection, and vascular grafts. Moreover, due to its homologous structure with native extracellular matrix, BC nanofibrous matrix could also be a potent candidate for tissue-engineered scaffolding materials. In this review, the characters and properties of BC, as a promising material for regenerative medicine, are summarized. The progresses made on application of BC to wound dressing, vascular grafts, meniscus and cartilage repair, bone healing, and other biomedical fields are expatiated in details. In the end, the future expectation of BC is briefly discussed. Overall, this low cost, biocompatible, and versatile nanomaterial could eventually be developed as an excellent platform for a new generation of medical device and regenerative medicine.