Experimental Study Of The Treament Of Rat Skin Photoaging By Platelet-rich Plasma Gel Combined With Erbiun Laser

Objective:To assess the effect of the 2940 nm Er: YAG laser and platelet-rich plasma(PRP)gel in treating photoaging by observing skin dermis thickness and changes of organizational structure,protein expression type I collagen and MMP-1、SOD,we try to explore a new way for clinical preferntial treament of photoaging.Methods:According to the different treatment,we classfy 50 healthy female SD rats into 5groups:A(The control group),B(UV-irradiated group),C(UV-irradiated +laser group),D(UV-irradiated + PRP gel injection group),E(UV-irradiated +laser+ PRP gel injection group).After 14 weeks of ultraviolet irradiation and 4 weeks laser treatment and(or)injection of PRP,We observe and record skin texture changes of rats.HE staining,Immunohistochem-istry and Western blot were employed to detect the skin structure in mice、theactivities of superoxide dismutase(SOD)、the contents of malondial dehyde(MDA)、I type collagen and MMP-1 protein expression.Results:(1)We can see the skin of photoaging SD rats turned to be grossly dry,scaling,apparent skin grooves and apparent pigmentation on the skin,decreased elasticity.The skin of the B(UV-irradiated group)rate are dry 、 rough and desquamation,we can see apparent skin grooves and apparent pigmentation 。Compared with group B,the skin of the E(UV-irradiated+laser+PRP gel injection group)rate improve markedly.the skin of the E(UV-irradiated+laser+PRP gel injection group)rate slightly better than group D and C.(2)Immunohistochemical results of type I collagen in the skin tissue showed that:the mean optical density in group B were significantly decreased compared with group A,(P <0.01);while after injected by the PRP gel or(and)laser therapy,the average optical density was decreased significantly,(P <0.05).(3)Compared group B((UV-irradiated group)with group C(UV-irradiated+laser group)and group D(UV-irradiated + PRP gel injection group),we can see epidermis significantly thinner,dermis thickness significantly increase from HE staining(P <0.05);dermal layer thickness of Group E(UV-irradiated+laser+ PRP gel injection group)were thicker than that in group B,(P <0.05),but the difference between group C and group D was little,no statistically significant.(4)We can see from Westernblot test results that,compared with group A,MMP-1 protein expression of group B was increased significantlyin(P <0.01),After PRP gel injecting or(and)laser therapying,compared group B with group C and group D,the expression of MMP-1 protein were significantly decreased,with statistical significance(P <0.05).Compared group E with group C and group D,the result are same with above,with statistically significant(P <0.05).All the result demonstrated that both PRP gel injection and laser therapy can decrease the expression of MMP-1,and they can reinforce each other;at the same time,ultraviolet radiation can increase the expression of MMP-1 markedly.(5)Superoxide dismutase(SOD)test results: the content of superoxide dismutase(SOD)in group B decreased significantly compared with group A and group E,(P < 0.01);while in group C、D、 E,the content of superoxide dismutase(SOD)significantly increased compared with group B(P < 0.05).Conclusion:Both injection of PRP gel and Er: YAG laser therapy in the treatment of skin photoaging can obviously stimulate the expression of type I collagen in the skin,lower the content of MMP-1 protein,improve the activity of SOD enzyme,promote skin collagen synthesis,and increase the thickness of the dermal layer of the skin,stimulate skin rejuvenation.In a word,Er: YAG laser laser and PRP rel has a coordinating role in the treating of skin photoaging.