Studies On The Effect Of Exogenous Hyaluronate In Skin Wound Healing

Wound healing in adults usualy results in scar formation or hypertrophic scar, which always affects the efficacy of plastic surgery. It is valuable to accelerate wound healing with less or without scar in plastic surgery. Studies in fetal wound healing showed that fetal wounds rich-in HA and healed rapidly without scar, which is abscent in adult wounds. According it we create arich-in HA milieu in adult skin wounds with exogenous HA and to research the posibility of accelerating adult wound healing with less scar by exogenous HA and the underlying mechanisms.[Methods] In animal experiments, 240 excisional skin wounds were made on the back of seven piglets(5 months of the age). Each wound was 2cm X 3cm in size and 1.5mm in depth. Then the wounds were designed into experiment and control ones. The experiment wounds were subdivided into groups of 0.5%,1.0%,2.0% HA solution and HA powder combined with bioglass or methylcellulose. On each specific wounds, 0.5ml HA gel or 100mg powder were used three times( just in operation, on the 3rd and 7th day after operation). Gross and histological observations were conducted to evaluate the efficacy of wound healing during 3-28 postoperative day. The contents of EGF, bFGF,GAG, HA and type III collagen in wounds were also tested to elaborate the effects of the exogenous HA we'd used.1.0% exogenous HA was applied on 20 wounds of donor site of medium thickness skin graft ( 0.3-0.5mm in thickness) of 16 patients. In each wound, equal part was chosen as experiment and control areas. HA gel (1.0ml HA gel per 50cm~2 each time)was used on experiment areas in operation and on the 3rd, 7th day after operation. During the first two weeks, we observed wound healing directly. All patients were followed up for 3-12 months. Histologic examinations were made with wound healing tissues of four volunteers.[Results] In animal experiment1. Experiment wounds dried on the 3rd day after operation and well epithelized on the 7th day. But the control parts dried on the 5th to 6th day and would not be covered by a newly epithelializedlayer till two weeks after operation. There was little difference between experiment and control wounds after 3 weeks on gross observation.2. By histologic examination and transmission electron microscopy, it was found that control wounds began to epithelize on the 7th day, fully epithelized in two weeks with serious acute inflamation and massive fibroblasts infiltration. HE sections also showed condensed and disordered collagen fibres and fibrous tubercles, abnormal papillary derm—without papillary rege and the dermalepidermal junction appeared to be a straight line. Experimental wounds began to epithelize...