The Experimental Research About The Wound Healing Promotion By Platelet-Rich Plasma Combined With Tissue-Engineered Skin

Objective:The study objective is to research the wound healing promotion by platelet-rich plasma (PRP) combined with tissue-engineered skin based on the model of nude mice wound.Methods:We gathered vein blood from 24 healthy volunteers and extracted platelet-rich plasma (PRP) using density gradient centrifugation and detecting the platelet levels by whole-blood cell analyzer. After activated by the activator, the concentration of growth factor was tested by ELISA to ensure the PRP was within the standard range.Then we treated the wound on nude mice with 5 different methods, such as artificial dermis (group A), tissue-engineered skin (group B), both basic fibroblast growth factor and tissue-engineered skin (group C), both epidermal growth factor and tissue-engineered skin (group D), both rich growth factor and tissue-engineered skin (group E). The biopsy was performed with HE, PAS, immunohistochemistry for PAN-CK, Vimentin, CK15, and CD29 on experiment day 3,7,14 and 21.Results:From this experiment, we found that the platelet concentration in the PRP is 4.5 times of the concentration in the vein blood and the concentration of growth factor in PRP is higher than that of vein blood.Different treatment methods achieved different results. The treatment with group E had the lowest infection rate, the fastest granulation tissue generation, and the thickest epidermal. HE staining showed highest concentration of vessels, and the best collagen and epidermal structure when comparing to other treatment methods. PAN-CK Immunohistochemical staining showed that the group E of epidermal cells had neat arrangement and higher degree of differentiation than group D. Vimentin immunohistochemical staining demonstrated that the dermal layer of the group C had better alignment than the group E. The results of CK15, CD29 immunohistochemical staining in all groups except artificial dermis indicated the presence of positive cells which suggested the growth of epidermal stem cells.Conclusion:Utilizing density gradient centrifugation can successfully construct PRP, which contains a variety of high concentration of growth factors.The treatment with rich growth factor and tissue-engineered skin had the best result, both basic fibroblast growth factor and tissue-engineered skin or both epidermal growth factor and tissue-engineered skin had the second result. The treatment with tissue-engineered skin had the better result than the artificial dermis.Through combining multiple kinds of growth factors and tissue-engineered skin combinations can result in treating the skin wound more effectively.