Gelatin hydrogel impregnated with platelet-rich plasma releasate promotes angiogenesis and wound healing in murine model

Platelet-rich plasma (PRP) contains numerous growth factors to promote wound healing and angiogenesis. The objective of this study was to explore the efficacy of biodegradable gelatin hydrogel impregnated with PRP releasate (PRPr) in the wound healing process compared with the single application of PRPr prepared from mouse PRP centrifuged by a double-spin method. Gelatin hydrogel disks with an isoelectric point of 5.0 were used in this study. A total of 180 mice (n = 45/group) were randomly assigned to the following 4 experimental groups: control group, biodegradable gelatin hydrogel group, PRPr group and gelatin hydrogel impregnated with PRPr (PRPrG) group. Wound area and epithelialization were compared on days 1, 5, 7, 14 and 21 post-wounding. After complete epithelialization, wound contraction was also evaluated. Neovascularization using immunohistochemical staining of von Willebrand factor was analyzed on day 14. The wound area of PRPrG on days 5, 7 and 14 was smaller than that in the other groups (p < 0.01). The epithelialization lengths of PRPrG on days 7 and 14 were significantly longer than the others (p < 0.01). The capillary formation of PRPrG was also superior to those in all other groups on day 14. On day 21, all wounds were completely epithelialized and PRPrG prevented wound contraction the most. It is concluded that the sustained-release system of gelatin impregnated with PRPr can stimulate angiogenesis and accelerate wound healing compared with the single application of PRP.