Cytotoxicity testing of burn wound dressings: first results

Application of bacterial nanocellulose-based wound dressings in the management of thermal injuries: Experience in 92 children

BACKGROUND

Management of pediatric thermal injuries involves a high standard of care in a multidisciplinary setting. To avoid physical and psychological sequelae, wound dressings should minimize hospitalization time and anesthesia while maximizing patient comfort.

PATIENTS AND METHODS

190 children with thermal injuries of the torso, arms and legs were treated with polyurethane foam dressings or bacterial nanocellulose sheets. Data were analyzed retrospectively regarding hospitalization, procedures with general anesthesia, scar formation, rate of infection and need for skin grafting.

RESULTS

The groups did not differ significantly concerning age, gender distribution or percentage of injured total body surface area. Statistical analysis showed that length of hospitalized care and procedures undergoing anesthesia were significantly reduced in the nanocellulose group (each p < 0.0001). There was no significant difference in rate of complications, wound healing and rate of skin grafting between the two subgroups.

DISCUSSION

Acting as a temporary epidermal substitute, bacterial nanocellulose enables undisturbed reepithelialization without further wound dressing changes. In children, no additional topical antimicrobial agents are indicated for unimpaired wound healing.

CONCLUSIONS

Bacterial nanocellulose is superior to polyurethane foam regarding length of hospitalization and number of interventions under anesthesia. It offers a safe, cost-effective treatment option and provides excellent comfort in pediatric patients.

Cytotoxicity and Wound Closure Evaluation in Skin Cell Lines after Treatment with Common Antiseptics for Clinical Use

In recent years, new therapies, such as skin cell lines injections, have emerged to promote re-epithelialization of damaged areas such as chronic ulcers or to treat patients with severe burns. Antiseptics are commonly used during wound clinical management to avoid serious infections, but they may delay the healing process due to their apparent cytotoxicity to skin cells. The cytotoxicity of ethanol, chlorhexidine digluconate, sodium hypochlorite, povidone iodine and polyhexanide was evaluated in this in vitro study on human fibroblasts and keratinocytes. Treatments were applied to each cell type culture every 48 h for 14 days. To determine the cytotoxic of antiseptics, cell viability (Live/Dead^®) and cell proliferation (AlamarBlue™) assays were performed on cell monolayers. Cell migration capacity was evaluated with a wound closure assay. Results showed how chlorhexidine digluconate and ethanol significantly reduced the viability of keratinocytes and inhibited cell migration. Povidone iodine followed by chlorhexidine digluconate significantly reduced fibroblast cell viability. Povidone iodine also inhibited cell migration. Sodium hypochlorite was the least detrimental to both cell types. If epithelial integrity is affected, the wound healing process may be altered, so the information gathered in this study may be useful in selecting the least aggressive antiseptic after treatment with new emerging therapies.

In Vitro Efficacy of Bacterial Cellulose Dressings Chemisorbed with Antiseptics against Biofilm Formed by Pathogens Isolated from Chronic Wounds

Local administration of antiseptics is required to prevent and fight against biofilm-based infections of chronic wounds. One of the methods used for delivering antiseptics to infected wounds is the application of dressings chemisorbed with antimicrobials. Dressings made of bacterial cellulose (BC) display several features, making them suitable for such a purpose. This work aimed to compare the activity of commonly used antiseptic molecules: octenidine, polyhexanide, povidone-iodine, chlorhexidine, ethacridine lactate, and hypochlorous solutions and to evaluate their usefulness as active substances of BC dressings against 48 bacterial strains (8 species) and 6 yeast strains (1 species). A silver dressing was applied as a control material of proven antimicrobial activity. The methodology applied included the assessment of minimal inhibitory concentrations (MIC) and minimal biofilm eradication concentration (MBEC), the modified disc-diffusion method, and the modified antibiofilm dressing activity measurement (A.D.A.M.) method. While in 96-well plate-based methods (MIC and MBEC assessment), the highest antimicrobial activity was recorded for chlorhexidine, in the modified disc-diffusion method and in the modified A.D.A.M test, povidone-iodine performed the best. In an in vitro setting simulating chronic wound conditions, BC dressings chemisorbed with polyhexanide, octenidine, or povidone-iodine displayed a similar or even higher antibiofilm activity than the control dressing containing silver molecules. If translated into clinical conditions, the obtained results suggest high applicability of BC dressings chemisorbed with antiseptics to eradicate biofilm from chronic wounds.

A Review of the Most Impactful Published Pharmacotherapy-Pertinent Literature of 2017 and 2018 for Clinicians Caring for Patients with Burn or Inhalation Injuries

Staying current and evaluating literature related to pharmacotherapy in burn or inhalation injury can be difficult as burn care teams are multidisciplinary and pertinent content can be spread across a plethora of journals. The goal of this review is to critically evaluate recently published pharmacotherapy-pertinent literature, assist practitioners staying current, and better identify potential future research targets. Twelve board-certified clinical pharmacists with experience caring for patients with burn and inhalation injuries reviewed and graded scientific literature published in 2017 and 2018. An MeSH-based search revealed 1158 articles related to burns, which were published during the 2-year period. One-hundred fifty one were determined to be potentially related to pharmacotherapy. After exclusions, only 82 (7%) remained for scoring, and the top 10 comprehensively presented. More than half of the reviewed manuscripts were assessed as lacking a significant impact on pharmacotherapy. There is a need for higher impact literature to support pharmacotherapy-pertinent treatment of such complex patients.

In vitro cellular viability studies on a concentrated surfactant-based wound dressing

In this study, three cellular cytotoxic assays (direct contact assay, extraction assay, and cell insert assay) were applied to evaluate the effects of a concentrated surfactant gel preserved with antimicrobials and a concentrated surfactant gel with 1% silver sulfadiazine on both the mouse fibroblast cell line L929 and human dermal fibroblasts (HDFa). Also, the in vitro wound model was wounded by a 100 μL pipette tip and used to assess cell migration and wound closure after treatment with both gels. A needle-scratched membrane disruption model was used to preliminarily evaluate membrane stabilisation and the membrane-resealing effects of concentrated surfactant gels. It was demonstrated that the concentrated surfactant gel preserved with antimicrobials was not toxic to both L929 and HDFa. However, the concentrated surfactant gel with 1% silver sulfadiazine demonstrated a degree of cytotoxicity to both cell types. After treatment with a concentrated surfactant gel preserved with antimicrobials, cell movement to close the scratch gap was enhanced at 24 and 48 hours. The results also showed that cells treated with the concentrated surfactant gel preserved with antimicrobials decreased cell necrosis and improved cell resistance of the f-actin rearrangement after a needle scratch. The results demonstrated that a concentrated surfactant gel preserved with antimicrobials is non-cytotoxic and has ability to accelerate wound closure by enhancing cell mobility. Furthermore, the concentrated surfactant gel appeared to stabilise the plasma membrane and demonstrated a resealing ability and helped to retain the plasma membrane integrity and enhanced wound healing.

Comparative effectiveness of Biobrane®, RECELL® Autologous skin Cell suspension and Silver dressings in partial thickness paediatric burns: BRACS randomised trial protocol

BACKGROUND

Mixed partial thickness burns are the most common depth of burn injury managed at a large Australian paediatric hospital specialty burns unit. Prolonged time until re-epithelialisation is associated with increased burn depth and scar formation. Whilst current wound management approaches have benefits such as anti-microbial cover, these are not without inherent limitations including multiple dressing changes. The Biobrane® RECELL® Autologous skin Cell suspension and Silver dressings (BRACS) trial aims to identify the most effective wound management approach for mixed partial thickness injuries in children.

METHODS

All children presenting with an acute burn injury to the study site will be screened for eligibility. This is a single-centre, three-arm, parallel group, randomised trial. Children younger than 16 years, with burns ≥ 5% total body surface area involving any anatomical location, up to 48 h after the burn injury, and of a superficial partial to mid-dermal depth, will be included. A sample size of 84 participants will be randomised to standard silver dressing or a Regenerative Epithelial Suspension (RES™) with Biobrane® or Biobrane® alone. The first dressing will be applied under general anaesthesia and subsequent dressings will be changed every 3 to 5 days until the wound is ≥ 95% re-epithelialised, with re-epithelialisation time the primary outcome. Secondary outcomes of acute pain, acute itch, scar severity, health-related quality of life, treatment satisfaction, dressing application ease and healthcare resource use will be assessed at each dressing change and 3, 6 and 12 months post-burn injury.

DISCUSSION

The findings of this study can potentially change the wound management approach for superficial partial to mid-dermal burns in children locally and worldwide.

TRIAL REGISTRATION

The Australian New Zealand Clinical Trials Registry (ACTRN12618000245291) approved prospective registration on 15 February 2018. Registration details can be viewed at https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374272&isReview=true.

Postoperative effects on lower third molars of using mouthwashes with super-oxidized solution versus 0.2% chlorhexidine gel: A randomized double-blind trial

BACKGROUND

The main objective of the present study is to evaluate the effects and possible benefits with regard to the postoperative period of lower third molar extractions, comparing the intraalveolar application of a bioadhesive gel of 0.2% chlorhexidine (CHX) to the use of a mouthwash with a super-oxidized solution, (SOS) Dermacyn® Wound Care (Oculus Innovative Sciences lnc., California, USA).

MATERIAL AND METHODS

A randomized double-blind study was carried out in 20 patients with a split-mouth design, with a total of 40 extractions of symmetrically impacted bilateral lower third molars. Patients were divided into two groups, a control group (C = 20) and an experimental group (D = 20). Any infectious complications, wound healing, plaque accumulation in the stitches, and presence of trismus and inflammation were evaluated using the distance between different facial points, at three, eight, and fifteen days after extraction. Pain, swelling, and amount of analgesics taken were evaluated using the VAS scale throughout the 15 days following extraction. Tolerance to treatment was evaluated using a verbal scale. Results were statistically compared using the Student's t- and chi-squared tests.

RESULTS

No statistically significant differences were found between the two groups with regard to infectious complications, swelling, or wound healing. Use of analgesics and self-reported pain levels were slightly lower in the experimental group than in the control group during days 6 and 7 of the study (p < 0.05). The global treatment tolerance was satisfactory and similar in both groups.

CONCLUSIONS

Both CHX and SOS are effective at improving the postoperative period after extraction of lower third molars.

Natural actives for wound healing: A review

Nature has been a source of medicinal treatments for thousands of years, with the use of plants as prototypes for drug development and for the extraction of active compounds. Skin injuries occur regularly in everyday life, and the human skin has the ability to promote repair spontaneously under healthy conditions. However, some intrinsic and external factors may interfere with skins' natural ability, leading to nonhealing lesions and chronic wounds, which directly affect health and quality of life. Thus, attention should be given to this health problem, using an appropriated management when necessary. In this scenario, phytotherapy may be an option for cutaneous wound treatment, although further high-quality studies are needed to firmly establish the clinical efficacy of plants. This article reviews traditionally used natural actives for wound healing, highlighting their characteristics and mode of action.

Topical Antimicrobials in Burn Care: Part 1-Topical Antiseptics

Burn wounds disrupt the body's primary defense against invasion and colonization by microorganisms. Topical antimicrobials are one component in burn wound care. These agents suppress microbial growth to advantage skin cells and wound healing. Topical antimicrobials can be divided into 2 superclasses: antiseptics and antibiotics. We review the 4 main classes of topical antiseptics (emulsifiers, acids, oxidizers, and heavy metals) and antiseptic-impregnated dressings in current clinical use and address the mechanisms, as well as the advantages and disadvantages of each antiseptic for burn wound management.