Study On The Effect Of EGF-CP-HA Hydrogel On Skin Wound Healing

ObjectiveTo explore the effect of EGF-CP-HA hydrogel on wound healing of full-thickness skin defect in rats.Methods90 SD rats were randomly divided into groups A,B,C,D and E,with 18 rats in each group.After anesthesia,the circular full-thickness skin on both sides of the spine of the rat was excised with a 1.2 cm diameter corneal circumcision to prepare a wound animal model.Four kinds of hydrogels were prepared: HA hydrogel(hyaluronic acid hydrogel),CP-HA hydrogel(collagen peptide-hyaluronic acid hydrogel),EGF-HA hydrogel(hyaluronic acidloaded epidermal growth factor hydrogel)and EGF-CP-HA(collagen peptide-hyaluronic acid-loaded epidermal growth factor hydrogel).Four kinds of hydrogels were applied randomly to the wound defect of each group,while normal saline(NS)was applied to the control group.The number of rats and the corresponding hydrogel types were recorded,and then sterile Vaseline gauze was applied on the wound.The day of modeling was recorded as day 0.After that,the wounds and general conditions of the rats were observed and recorded every day,and the wounds were photographed every 3 days to observe and record the wound healing.A group of rats were randomly selected on the 3rd,7th,11 th,14th,21 st and 28 th postoperative day.The wound and its tissue at 1 cm around the wound were anesthetized,and then the animals were sacrificed.The specimens were made into paraffin tissue sections,and then HE,Masson,and immunohistochemical staining were performed to observe the histopathological changes,collagen fiber distribution,and expression of VEGF-? and TGF-?1 in the injured area at different times.Results1.The wound healing was observed and recorded.On the 12 th day after the operation,the wounds in the EGF-CP-HA group reached the healing standard,and the other groups did not reach the healing standard.Compared with the NS group,the EGF-CP-HA hydrogel promoted the wound healing rate of the skin and shortened the wound healing time(P < 0.01).2.The remaining area of the wound in the rats was counted.Compared with the NS group,the wound area of the experimental group was reduced to 3,7,and 11 days after surgery,and the wound area of the EGF-CP-HA group was reduced.The other groups were more obvious(P < 0.01).3.HE staining was performed on the wounds on the 3rd,14 th and 21 st postoperative day.It was observed that the inflammatory reaction of the EGF-CP-HA group was lighter than that of the NS group,the rate of granulation tissue formation,capillary and collagen fiber formation.More than the other groups.4.Masson trichrome staining was performed on the wounds on the 3rd,14 th and 21 st postoperative day.The results showed that the EGF-CP-HA group had more collagen fibers than other groups,arranged regularly,orderly,and closer to normal skin.5.The results of immunohistochemical staining showed that the expression levels of VEGF-? and TGF-?1 in EGF-CP-HA group were higher than those in the control group(P <0.05).6.The results of immunohistochemical staining showed that the number of capillaries in EGF-CP-HA group was significantly higher than that in control group.ConclusionEGF-CP-HA hydrogel can reduce the inflammation of wound,promote the expression of VEGF-? and TGF-?1 in wound healing,and obviously promote wound healing.