Cath Lab Digest

Index: Ostomy Wound Manage 2001;47(11):44–51

  The 7th Annual Conference of the Canadian Association of Wound Care met in London, Ontario, November 1 through 3. The focus of the conference was "The Many Faces of Wound Caring: Interdisciplinary Teams Providing Patient-Centered Care." Ostomy/Wound Management is fortunate to have received a number of rigorously reviewed abstracts presented at CAWC that illustrate the breadth and depth of research relevant to wound care. These abstracts were selected for publication by an interdisciplinary abstract review committee comprising a total of seven of the authors' peers. An equal number of abstracts were selected from oral and poster presentations. In publishing these abstracts, the editors hope to increase attention to the issues they address, expedite necessary changes to care protocols, and stimulate further research efforts among clinicians who may take the value of their day-to-day accumulation of knowledge for granted.

A Potential Use of Liposome Associated Interferon-alpha-2b for Treatment of Post-Burn Hypertrophic Scar
A. Ghahary, E.E. Tredget, and M. Takeuchi, Wound Healing Research Center, University of Alberta, Edmonton, Alberta, Canada
  As previously reported, interferon-alpha-2b (IFN-a2b) can be encapsulated in liposomes without compromising its antifibrogenic effects on dermal fibroblasts in vitro. This study was conducted to determine whether this preparation, applied topically to dorsal guinea pig wounds, can improve the fibrotic conditions. The rationale for this approach is that the systemic administration of IFN-a2b by subcutaneous injection for treatment of dermal fibrosis is uncomfortable, requiring large quantities of the cytokine, and cannot be easily used in children. Liposomes are a potentially useful vehicle for the topical delivery of drugs. Empty sonicated liposome vesicles were mixed with various concentrations of IFN-a2b and then dried and rehydrated. An enzyme-linked immunosorbent assay (ELISA) was used to determine the efficiency of encapsulation and the stability of the preparation under experimental conditions. A total of 36 full-thickness skin wounds (six/animal, three on each side) were made with an 8-mm disposable punch. Each wound on the right side was treated with liposome cream (100 mg/wound) containing 3,000 units of liposome-encapsulated IFN-a2b. Wounds on the left side were treated with empty liposomes. A significant reduction in rate of wound contraction occurred. This reduction remained significant up to 10 days. Northern analysis, used to evaluate the expression of mRNAs for type I and type III collagens in response to IFN-a2b, showed a marked reduction in the abundance of the transcripts for the pro-a 1(I) chain of type 1 collagen on days 11 and 14 after wounding. Similarly, the level of mRNA for type III procollagen was markedly reduced as early as day 7 and remained depressed up to day 14. These findings were consistent with results obtained for the total collagen content in tissue samples. Cellularity of the IFN-a2b-treated wounds, assessed by vimentin content, was also markedly reduced at day 7 and remained depressed up to day 14. Liposome associated IFN- a2b applied 5 days after completion of epithelialization reduced the mRNA for the pro-a 1(I) chain of type 1 collagen, confirming its transepidermal penetration and effectiveness. The activity of liposome-associated IFN-a2b in vivo supports the concept of the topical use of this antifibrogenic agent for treatment of fibroproliferative disorders.

  This study has been supported by the Toronto Hospital for Sick Children Foundation.

The Leg Ulcer Measurement Tool: Can It Detect Change in Wound Appearance?
M.G. Woodbury, Parkwood Hospital, St. Joseph's Health Care, London, Ontario; P.E. Houghton, School of Physical Therapy, University Western Ontario, London, Ontario, Canada; K.E.