Experimental Study On The Effect Of Platelet-rich Plasma (PRP) On The Enhancement Of Angiogenesis And Cell Proliferation In Diabetic Wound Healing

Objective:The aim of the study was to investigate the effect of platelet-rich plasma(PRP)on wound healing in diabetic mice,and to definite the effect of PRP on the enhancement of angiogenesis and cell proliferation in diabetic wound healing.Methods: The 8-week healthy KM male mice were taken as the research animal models.The animal models were induced by injecting streptozotocin(STZ)intraperitoneally.The full thickness skin wound healing model was established by creating a 1 cm2 full-thickness excision skin wound on the back of diabetic mice.The mice were randomly divided into two groups: the experimental group(the PRP-treated group,n=40)and the controlled group(the saline-treated group,n=40).The wounded mice in the two groups were treated daily.The wounded areas in the two groups were recorded by a digital camera.Time to closure and percentage closure were calculated by morphometry respectively.Animals in the two groups were sacrificed on days 3,7,10,and 14 post-operatively.The changes of the tissue histopathology were observed by the method of hematoxylin-eosin(HE)staining.The cell proliferation in granulation tissues at the wound site in each group was studied by PCNA staining using immunohistochemical(IHC)method.The CD31 IHC staining method was used to measure the new blood vessels in granulation tissues.The purpose of the above applied methods was to verify the effect of PRP on enhancing diabetic wound healing by promoting angiogenesis and cell proliferation.Results: On days 3,7,10,and 14 after treatment,the wound closure rate in the controlled groups and experimental groups was(14.72±3.17)%VS.(32.18±3.82)%,(39.81±4.29)%VS.(58.28±5.13)%,(69.62±3.12)%VS.(84.27±3.37)%,and(79.12±4.26)%VS.(95.36±2.63)%,respectively.The wound closure rate was higher in the experimental group than in the controlled group(P<0.05).It showed that the wound closure time in the controlled and experimental group was(18.13±0.14)and(13.95±0.20)days respectively(P<0.05).Compared to the controlled group,The HE staining results in the experimental group showed that the inflammatory cells were found to have infiltrated into the tissues on days 3 post-operatively.The granulation tissue was formed on days 7 post-operatively,and a small amount of fibroblasts and new blood vessels were observed in the granulation tissue.A large number of fibroblasts and new blood vessels were observed in the granulation tissue on days10 post-operatively.On days 14 post-operatively,the wound was almost closed,and a complete skin structure was formed at the wound site.The IHC staining result showed that the number of CD31 staining positive cells in the tissue in the controlled groups and the experimental groups was(2.62±0.37)VS.(7.50±0.72,(7.12±0.11)VS.(14.89±1.23),(9.73±0.81)VS.(21.24±1.49),and(19.76±0.85)VS.(32.39±1.72),on days 3,7,10,and 14 post-operatively(P<0.05).IHC for CD31 revealed well-formed blood vessels with increased microvessel density on days 3,7,10,and 14 in the experimental group.The IHC staining result showed that the number of PCNA staining positive cells in the tissue in controlled groups and experimental groups was(379.62±86.37)VS.(602.37±131.02),(829.25±100.92)VS.(1311.12±108.23),and(917.74±78.05)VS.(1494.23±99.27),on days 3,7,and 10 post-operatively(P<0.05).IHC for PCNA revealed increased cell proliferation in the experimental groups.On days 14post-operatively,the number of PCNA staining positive cells in the tissue in controlled groups and experimental groups was(1280.63±86.51)and(914.58±94.74)(P<0.05).Conclusion: PRP enhanced the formation of granulation tissues at the wound site,shortened wound closure time,and improved wound healing rate.PRP could improve wound healing by enhancing angiogenesis and proliferation.