Clinical efficacy of wound dressing containing silk sericin for split-thickness skin graft donor site treatment

Abstract

The objective of this study was to investigate the safety profile of silk sericin dressing using patch test in healthy volunteers during April 2011 to January 2012 at the Department of Pharmacy Practice, Pharmaceutical Sciences, Chulalongkorn University and Police General Hospital. We also would like to study the clinical efficacy of this dressing for Split-Thickness Skin Graft (STSG) donor site treatment compared with Bactigras®, a standard treatment, during March to December 2012 at the Division of Plastic and Reconstructive Surgery, Department of Surgery, King Chulalongkorn Memorial Hospital. One hundred and ten healthy volunteers were included and complied with patch test protocol by randomly applying silk sericin dressing and Bactigras® on the back for 3 days twice. Seven and ten days later, both dressings were re-applied on the same areas and left for another 3 days in the challenge phase. There was no significant difference in skin irritation including the change of skin color measured by Mexameter MX18® and Human Repeat Insult Patch Test (HRIPT) scale, evaluated by 3 dermatologists, between the skin treated with silk sericin dressings and Bactigras® (p>0.05). Twenty-eight patients with 30 STSG donor sites were enrolled in this study. The donor sites were equally divided into two parts, one part treated with silk sericin dressing and Bactigras® was applied to another. The results showed that the median of time for complete healing as well as pain scores assessed by patients during 5 postoperative days consecutively on the side treated with silk sericin dressing were significantly lower than those treated with Bactigras® (p<0.05). Two sites treated with silk sericin dressing (6.7%) showed signs of infection while no sign of infection was found in Bactigras®-treated sites. Initially, blood biochemistry data including AST, ALT, ALP, BUN and fasting blood sugar were elevated but then decreased within 7-14 days later while albumin, blood electrolytes and blood compositions were changed insignificantly pre- and post-operation (p>0.05). On the first post-operative day, serum pro-inflammatory cytokines (IL-6 and TNF-α) increased significantly (p<0.05) and then returned to baseline levels on day 7-14 post-operation. According to microscope images of the dressing after peeling off, epithelial cells attached more tightly on Bactigras® than silk sericin dressing. Better morphology and complete border of epithelial cells found on silk sericin dressing after peeling off. In conclusion, silk sericin dressing accelerates healing process and significantly reduced pain, comparing to that of Bactigras® without serious adverse events. Therefore, we introduce silk sericin dressing as an alternative treatment for STSG donor site.