1. Silk sericin wound dressing may reduce time for complete epithelialisation of split-thickness skin graft donor sites compared to Bactigras®.
2. Silk sericin wound dressing may reduce pain level at split-thickness skin graft donor sites compared to Bactigras® .
3. Silk sericin wound dressing may not cause split-thickness skin graft donor sites infection as compared to Bactigras®.
4. Split-thickness skin graft donor sites which treat by silk sericin wound dressing may not cause significant adverse events.

Split-thickness skin graft (STSG) is a surgical procedure to repair losses of skin by transferring of a section of healthy skin (donor site) to replace the damaged tissue in another area of the body (recipient site). However, the patients will have a new wound at donor sites which need appropriate wound dressing to increase healing and reduce complications. Since silk sericin can form a dressing which can accelerate wound healing process and protect wound from environment, the aim of this study is to investigate how well silk sericin wound dressing cures STSG donor sites by comparing to Bactigras® which is a commonly used paraffin-impregnated fine mesh gauze. Silk sericin wound dressing is a promising material which can shorten the treatment course and reduce pain for the patients who have donor sites. This study design is a single-center, randomized, open and paralleled positive control study.18-60- year-old patients of both genders who undergo STSG at anterolateral thigh in Division of plastic and reconstructive surgery, King Chulalongkorn Memorial Hospital from April 2012 to January 2013 will be recruited in the study. The thickness of donor sites fall between 0.15-0.45 mm (0.006-0.018 inches) and their sizes are at least 100 cm2. The exclusion criteria are donor sites other than thigh or located at high risk of infection. Patients who are immunocompromised or mental defect, who are unlikely to comply with protocol or pregnant or lactating or known hypersensitivity to the investigational products are also excluded. All subjects sign the informed consents after an overall discussion of the protocol, its rationale and the potential risks. Donor sites are equally divided into 2 parts; upper and lower part of the leg. Using a random number table allocation, silk sericin wound dressing is randomly applied on one half and the other half will be covered by Bactigras®. Postoperatively, surgeons will observe all donor sites daily for treatment evaluation and any possible local adverse events without removing the primary dressings, except there is excessive fluid leakage or any sign of infection. Patients assess for pain level in every observations by using Visual Analog Scale. Time for complete epithelialisation is duration between finishing surgical procedure and the dressing spontaneously peeling off from donor sites without causing pain. If there is any sign of infection such as swelling, edema, purulent discharge, bad odor, a swab evaluation at the suspected area will be done to find an appropriate management. Blood sample will be collected from patients pre- and postoperatively (with in 24h, day3 and before patient discharge) for CBC, blood glucose, electrolyte, hepatic and renal function analysis and proinflammatory cytokine measurement. This study may show any possible adverse events, both local and systemic effect, caused by silk sericin dressing. Proinflammatory cytokines patterns of the patients underwent STSG will be revealed in this study which may be relate to clinical outcomes.

Inclusion Criteria:

• Aged 18-60 years
• Patients who require STSG such as burn, trauma, venous ulcers, or surgical removal of cutaneous malignancies etc.
• Patients whom surgeons assess that ready for undergoing STSG
• Sufficient normal skin at anterolateral thigh area for 1 or more STSG donor sites
• The thickness of donor sites fall between 0.15-0.45 mm (0.006-0.018 inches) and their sizes are at least 100 cm2
• Patients who are willing to participate in the trial and to sign the informed consent form.

Exclusion Criteria:

• Use others area for STSG donor sites other than thigh
• Donor sites are located at high risk of infection such as harvesting closed to current infective wound (excessive purulent discharge or bad odor)
• Patients who are immunocompromised or mental defect
• Patients who cannot or not willing to comply with the study protocol
• Known allergy or hypersensitivity reaction to silk sericin or chlorhexidine acetate
• Pregnancy or lactation