Objective      To determine the effects of a recombinant human platelet-derived growth factor (PDGF) produced by our team on the wound healing of combined radiation-trauma injury.      Methods      A rat model of combined radiation-trauma injury was established by whole body irradiation of 4 Gy

60

Co γ-ray followed by a round full-thickness skin wound at a diameter of 2 cm on the back in 2 h after irradiation. These rats were then randomly divided into 6 groups

that is

blank control

matrix control group

positive control

low-

median- and high-dose P

DGF with 20 rats in each group. After daily administration

the conditions of wound healing were documented and the percentages of both wound healing area and residual area were calculated. The morphology of the surface of wound was evaluated by observing the epithelial migration

granulation tissue growth and neovascular density. Immunohistochemical assay was used to detect the expression of Bcl-2

platelet-derived growth factor A chain (PDGF-A) and vascular endothelial growth factor (VEGF).      Results      Within the 1st to 14th days after the injury

the high dose rhThr6-PDGF-BB group had a faster healing

with the wound almost totally healed in 14 d. The healing was very slow in the blank control group

with 19% wound area remaining unhealed in 14 d after injury. The healing rate was significantly faster in the median- and high-dose groups than the blank control group (P0.05). The median- and high-dose groups had faster epithelial migration rate

earlier formation of granulation tissue

abundant fibroblasts and new capillaries than the control group

in which the high dose group was more obvious. Immunohistochemical assay revealed that the expression of Bcl-2

PDGF-A and VEGF was significant enhanced in the drug groups than in the control.      Conclusion      rhThr6-PDGF-BB remarkably accelerates the wound healing of combined radiation-trauma injury.