Experimental Study Of The Treatment Of Rat Skin Photoaging By Platelet-rich Plasma Gel

Objective:To observe skin dermis thickness and changes of organizational structure, protein expression type I collagen and MMP-1、TGF-β1, provide a new way of thinking for clinical preferntial treament of photoaging by platelet-rich plasma(PRP) gel.Methods:Using 40 healthy female SD rats, according to the different processing me thods are divided into four groups: group A: normal control group(none inter vention); Group B: skin was treated only with ultraviolet radiation; group C : s kin was treated with ultraviolet radiation and saline injection; Group D: skin was treated with ultraviolet radiation and PRP gel injection.HE staining,Masson staining,immunohistochemistry and Westernbolt were employed to detect the thi ckness of dermis in mice,I type collagen, MMP-1 and TGF-β1 protein expressi on.Results:(1)After 14 weeks of ultraviolet radiation, the skin of photoaging turned to be grossly dry, scaling, apparent skin grooves and apparent pigmentation on the skin, decreased elasticity.(2) Compared with group B(UV- irradiated group) and group C(UV- irradiated and saline injection group), the skin of the ela sticity were obviously improved of group D. It is clearly to see that skin is much smoother,more exquisite with wrinkles disappear totally.There is no obvious pigmentation in the naked eyes.(3) Compared with group B(UV- irradiated group) and group C(UV- irradiated and saline injection group),we can see significantly thinner epidermis, dermis thickness significantly increasefrom HE staining(P <0.01); although the dermal layer thickness of Group C were thicker than that in group B, but the difference was s mall, no statistically significant.(4) Immunohistochemical results of type I collagen in the skin tissue and TGF-β1 were expression in all groups.The mean optical density in group B were significantly decreased compared with group A,was decreased significantly(P <0.01); after injected by the PRP gel,the average OD were significant increase(P <0.01).(5) Westernblot test results showed, compared with group A, MMP-1 protein expression was significantly increased in group B(P <0.01), TGF-β1 expression was significantly decreased(P <0.01), shows that ultraviolet radiation significantly increased MMP-1 protein expression, decreased the expression of TGF-β1; After injected PRP gel,compared with group B and group C, the expression of TGF-β1 in group D were significantly increased,with statistical significance(P <0.05), the expression of MMP-1decreased, with statistically significant(P <0.05), showing that PRP gel injection can decrease the expression of MMP-1, and increase the expression of TGF-β1.Conclusion:Injection of PRP gel in the treatment of skin photoaging can effectively stimulate the expression of TGF-β1 and type I collagen in the skin, reduced MMP-1 protein expression, and promote skin collagen synthesis, increasing the thickness of the dermal layer of the skin and promote skin rejuvenation.