Experimental Study On Photosensitive Heparin Hydrogel Loaded With Lipogenic Growth Factor To Promote Wound Healing

Background: The wound problem is a growing medical challenge that affects millions of people around the world.As a relatively complex dynamic process,wound healing includes several stages of hemostasis,inflammation,proliferation and remodeling.It involves growth factors,cytokines,chemokines and the coordination between various cells.Failure at any stage of the process can result in slower wound recovery and abnormal scarring.On the one hand,chronic wounds are likely to have a negative impact on the living standards of patients;on the other hand,chronic wounds will bring huge economic burdens to patients due to the need for repeated treatment.With the advancement of materials science,regenerative medicine,and bioengineering technologies,the combination of exogenous growth factors with biomaterial scaffolds is expected to provide a very promising therapeutic strategy for wound healing.Objective: This study combined a photosensitive hydrogel based on heparin methacrylate(HepMA)with adipose-derived growth factor-rich adipose tissue extract(ALE),mainly to analyze and investigate its The role and influence in wound healing.The main purpose of this experiment is to provide some reference and reference for the application of growth factor-based wound dressings in skin injuries.Methods: In this experiment,ALE and HepMA hydrogel were combined to prepare an ALE-HepMA hydrogel,and its photosensitivity,microstructure,protein release capacity,adsorption capacity and biocompatibility were measured.To evaluate the effect of ALE-HepMA hydrogel on endothelial cells and fibroblasts,its ability to induce tube formation in human umbilical vein endothelial cells(HUVECs)and to promote the migration of L929 dermal fibroblasts was tested in vitro.In order to evaluate the effect of ALE-HepMA hydrogel in repairing wounds,this experiment established a full-thickness skin defect model of Barbisi mice,and injected 4% chloral hydrate(0.1m L/10g)into the anesthesia solution by intraperitoneal injection.mice,and excised dorsal skin.Twenty-four selected babassi mice were randomly divided into three groups: normal saline group,pure ALE group,and ALE-HepMA hydrogel combination group(ALE-HepMA).Administration of a single dose(300μL).In order to effectively prevent cross-contamination of all wounds,the wound area should be detected on the 4th,7th,and15 th days after drug treatment,respectively.Image J software was used to quantify the wound area and the wound healed.The condition is expressed as: residual wound area/original wound area×100%.On the 4th,7th,and 15 th days after the drug repair treatment,the Barbisi mice were sacrificed.At the same time,in order to evaluate the histology in a timely and effective manner,the skin tissue around the wounds of the mice was immediately extracted and stained with HE,Masson staining and CD31 immunohistochemistry were used to evaluate the changes of tissue morphogenesis,collagen deposition and angiogenesis in mice.Result:1.The results of the quality evaluation of HepMA hydrogels : the photosensitivity and biocompatibility of the hydrogels are relatively good,and it can be found by electron microscopy that there are many sponge-like structures,and these structures are connected to each other.,which is very beneficial to both the diffusion and release of growth factors.The results of the sustained-release experiments showed that ALE was continuously and smoothly released for a period of one week.The adsorption experiment results showed that HepMA hydrogel had better adsorption capacity for protein molecules.2.The in vivo experiments showed that the wound healing rate of the mice in the ALE-HepMA hydrogel group was the highest at each time point.After about half a month of administration,it was found that the wound healing of the mice in the ALE-HepMA group was Best,it is not difficult to see from the experimental results that when the wounds of the mice healed in the early stage,the wound healing at the wound site was better due to the synergistic effect between the lipid-derived growth factor rich in ALE and the HepMA hydrogel.Good and faster healing effect.3.In vitro experiments showed that compared with the control group,ALE-HepMA hydrogel could promote the tubular formation of HUVECs and significantly affect the migration of L929 fibroblasts.4.Compared with the control group,the results of immunohistochemistry showed that ALE-HepMA hydrogel had more CD31 expression.Compared with other groups,ALE-HepMA hydrogel had the most significant promoting effect on the formation of new blood vessels in the wound..5.Compared with other groups,ALE-HepMA hydrogel can promote and improve the deposition of collagen and the formation of granulation tissue at the wound site,which can be fully reflected by Masson staining and HE staining.Conclusion: Compared with other control groups,ALE-HepMA hydrogel has a great promoting and therapeutic effect on promoting the formation of new blood vessels,wound closure and granulation tissue formation.The experimental results show that the HepMA hydrogel loaded with adipose-derived growth factor is a growth factor delivery system with good biocompatibility,which will provide a promising therapeutic scheme for the treatment of wound healing.It is hoped that this experiment can provide some reference and reference for the use of growth factor-based wound dressings in skin injuries,and contribute to the relevant research on timely and effective promotion of wound healing.