Synthetic dressings

Stimulation of the proliferation of human dermal fibroblasts in vitro by a lipidocolloid dressing

OBJECTIVE

The effect of Urgotul on normal human dermal fibroblast proliferation was studied in vitro and compared with that of two other dressings: Mepitel and Tulle Gras.

METHOD

Proliferation was measured by the extent of thymidine incorporation into the replicating DNA of proliferative fibroblasts in contact with the complete dressing.Additional cell viability and metabolism were evaluated using MTT assay. Morphology and ultrastructure analysis were based on immunolabelling and confocal laser microscopy.

RESULTS

Only Urgotul significantly stimulated thymidine incorporation, generally with a maximal proliferative effect at a contact time of 48 hours. This was confirmed by the observation of a greater number of dividing cells (mitotic cells) than in the control cultures. No cytotoxicity was observed following treatment with this dressing. Cells exhibited normal structural and ultrastructural features.

CONCLUSION

Fibroblasts play a key role in dermal wound repair. The ability of Urgotul to promote fibroblast proliferation could explain its efficiency in the healing process of acute and chronic wounds.

DECLARATION OF INTEREST

This study was supported by Urgo Laboratories.

Comparison of different wound dressings on cultured human fibroblasts and collagen lattices

OBJECTIVE

We compared the effects on cultured human fibroblasts of a new non-adhesive wound dressing, Urgotul, with five other wound dressings. Urgotul is a hydrocolloid dressing; the comparator dressings included impregnated gauze and modern wound dressings.

METHOD

Cultures in monolayer were used to study the morphology and growth of fibroblasts. The Bell model of cultured dermis equivalents was used to investigate myofibroblast differentiation. These cultures were labelled a-SM actin and F-actin.

RESULTS

Two of the tested dressings induced cytotoxic effects. They were found to inhibit cell growth (greater than 60%) and to disturb cell shape and cytoskeletal differentiation. Urgotul and the remaining three dressings showed no effect on proliferation. However, some of them modified fibroblast morphology and affected F-actin distribution.

CONCLUSION

Depending on their nature and components, wound dressings may respect or affect fibroblast behaviour in vitro (proliferation, morphology and a-SM actin and F-actin distribution). The significance of these in vitro observed findings require further investigations.

Critiquing clinical research of new technologies for diabetic foot wound management

Healing the diabetic foot ulcer has been a challenge. Over the past 20 years, researchers have gained significant knowledge about the biochemical mechanisms that underlie the process of wound repair. A literature review of the latest advanced technologies, devices, and therapies is provided. In addition, clinical decision-making insights for clinicians to evaluate research and to assist in choosing the correct modality for each of their diabetic foot ulcer patients are discussed.

Postoperative care following CO2 laser resurfacing: avoiding pitfalls

Facial skin resurfacing using the carbon dioxide laser has become an increasingly popular procedure. Improvements in carbon dioxide laser technology have made the procedure simpler and more reliable. However, difficulties in the postoperative period can lead to patient morbidity and physician anxiety. Common problems such as prolonged erythema, hyperpigmentation, acne, milia, dermatitis, and infection can be controlled or avoided with proper postoperative care. Less common sequela such as hypertrophic scarring and prolonged healing are often a results of errors committed in the postoperative period. The authors have performed laser resurfacing in almost 2100 patients in the last 4 years. Changes in the postoperative regimen to include no pretreatment, use of semipermeable dressings, antiviral and antibacterial prophylaxis, and early treatment with sunscreens and bleaching agents have made for a smoother recovery with more predictable results.

Toxicity testing of wound dressing materials in vitro

There is a bewildering array of dressing materials available for wound coverage. The choice of dressing is often by local custom or practical experience. We wished to investigate if different dressings varied in their ability to either stimulate or inhibit proliferative activity and differentiation in an in vitro test system. We have used a number of test systems for this study. Human dermal fibroblast and keratinocyte cultures were used to screen for proliferative and cytotoxic effects. A more complex "organotypic" method involving fibroblast-impregnated collagen gels overlaid with epidermal keratinocytes was used to investigate effects on differentiation. Dressings were selected from each of the major types available, from simple gauze to hydrocolloids. Of the dressings tested, some reduced cell growth rates but the majority showed no major effect on proliferation or differentiation. Of those displaying an effect, only one could be attributed to cytotoxicity.

A reevaluation of the effect of occlusion on the trichloroacetic acid peel

BACKGROUND

Prior studies have demonstrated reduced wounding with trichloracetic acid (TCA) peels after tape occlusion. It is therefore reasonable to question whether or not other types of occlusion may have similar effects, particularly those used in routine postoperative care.

OBJECTIVE

To reevaluate the effect of occlusion after TCA peels in multiple human models using various forms of dressings, at various times postoperatively, and to make recommendations regarding wound care that will not adversely affect the efficacy of the peel.

METHODS

Equal-sized sections of anterior alopecic scalps of four patients were peeled with 50% TCA, occluded with bacitracin, Vigilon, or Tegaderm at various times postoperatively, and biopsied 1 day later. Depths of necrosis were measured and compared with nonoccluded controls.

RESULTS

Bacitracin ointment and Vigilon did not lessen TCA wounding, and sometimes actually enhanced it. Conversely, Tegaderm lessened the degree of the TCA wound. Timing of application played a role in the case of occlusion with Vigilon.

CONCLUSION

Occlusives used in conjunction with TCA peels do not have a uniform effect on depth of necrosis. Ointments and Vigilon can be used without reducing the efficacy of the TCA peel. Multiple subjects and rigid control of variables are necessary in studies of TCA-induced necrosis.