Optimal Concentration of Thrombin to Activate Platelet for Wound Healing

PURPOSE: Platelet transplantation is a novel therapeutic strategy for acceleration of wound healing. When applying platelets, efficacy of adding thrombin to stimulate growth factor release from platelets has already been proven. However, no quantitative data of the thrombin treatment has been reported. The purpose of this study is to determine the optimal thrombin concentration to maximize growth factor release of platelets. In particular, this study was designed to quantify levels of platelet derived growth factor(PDGF)-BB, which is a major growth factor containing in the platelets, in vitro. METHODS: Fresh platelets were obtained from a blood bank. They were suspended in DMEM/F-12 and incubated with thrombin of various concentrations. The concentrations of thrombin tested were 0, 6.25, 12.5, 25, 50, 100, 200, and 400IU/mL. After 30 minutes, 1, 3, 5, and 7 days, the levels of PDGF-BB were measured using enzyme linked immunosorbent assay. Platelets from four donors were included in this study. Each sample was tested in triplicate and the mean value was used as a data for each sample. RESULTS: The addition of thrombin increased the level of PDGF-BB. Increases in storage time of platelets resulted in decreased levels of PDGF-BB. Higher levels of PDGF were detected in consort with increased thrombin concentrations. However, there was no significant difference between samples of 200 and 400IU/mL concentrations. CONCLUSION: The results indicate that adding thrombin accelerates the release of growth factors from platelets and the optimal thrombin concentration to maximize this function is 200IU/mL.

Treatment of Diabetic Ulcer using Autologous Fibroblast-Hyaluronic Acid Complex

PURPOSE: To evaluate clinical efficacy and safety of hyaluronic acid based autologous dermal fibroblasts (Hyalograft 3D) in the treatment of diabetic foot ulcers. METHODS: A total of 28 patients with diabetic ulcers were randomized to either the control group with nonadherent foam dressings(n=14) or the treatment group with autologous tissue-engineered grafts(n=14). Weekly assessment contained vital sign checks, ulcer size measurements, and wound photos. In the 12th week, percentages of complete wound healing and mean healing times were compared. Safety was also monitored by adverse events. RESULTS: Complete wound healing was achieved in 84.6% of the treatment group and 23.1% of the control group(p<0.005). The mean times of closures for the treatment versus control groups were 6.1 weeks and 10.9 weeks, respectively. No adverse events related to the study treatment occurred. CONCLUSION: The use of hyaluronic acid based autologous fibroblast grafts was found to be a safe and effective treatment for diabetic foot ulcers.