Construction And Performance Study Of GelMA Hydrogel/Acupuncture Acellular Valve Composite Scaffold With Different Concentrations

Heart valve disease is a worldwide clinical disease that can cause high morbidity and high mortality.As an emerging technology for the treatment of heart valve diseases,tissue engineered heart valves are widely favored.Among them,decellularized heart valve scaffolds are biocompatible and biodegradable because they can retain the structure and performance of natural heart valves,and are often used to prepare tissue engineered heart valves.However,after decellularization of the heterogeneous heart valve,the binding force between the autologous cells and the surface and the adhesion rate of the autologous cells on the surface may be poor,which will seriously affect the construction and implantation of tissue-engineered heart valves.In response to this problem,this paper use a hydrogel for coating cells,and at the same time acupuncture the surface of the acellular heart valve,and further constructs excellent performance of methacrylic acid acylated gelatin(GelMA)/hydrogel acupuncture Decellularized valve composite scaffold,and explored the influence of the concentration of hydrogel on the performance of GelMA hydrogel/acupuncture acellular valve composite scaffold.This article has conducted the following three-step research:(1)Concentration is one of the important factors affecting the degree of crosslinking,structure and performance of hydrogels.Therefore,in order to better use the hydrogel system,the first step is to explore the influence of hydrogel concentration on the structure and performance of GelMA hydrogel.In this paper,three concentrations of GelMA hydrogel were prepared,and the effects of concentration on the structure and performance of the hydrogel were studied by testing its microscopic morphology,pore size distribution,rheology,swelling properties,mechanical properties,surface viscosity and degradation rate.Impact.The results show that the higher the concentration of GelMA hydrogel,the tighter the pore structure inside the GelMA hydrogel,the smaller the average pore size,and the stronger mechanical properties and lower surface viscosity.However,high-concentration GelMA hydrogels will show poor swelling properties.In addition,the concentration has no significant effect on the degradation performance of GelMA hydrogels,and the GelMA hydrogels at each concentration show a slow degradation rate in vitro.At the same time,by characterizing the adhesion,proliferation,activity and morphology of HUVEC on the surface of the hydrogel,the effect of concentration on the biocompatibility of GelMA hydrogel was explored.The results showed that: on the surface of GelMA hydrogel of each concentration,HUVEC showed higher cell activity.At the same time,the higher the concentration of GelMA hydrogel,the better the adhesion and proliferation ability of HUVEC on its surface.However,compared with the control group,HUVEC was difficult to spread on the surface of the GelMA hydrogel of each concentration,and it was distributed on the surface of the hydrogel in a round shape.(2)Using a hydrogel system for the three-dimensional culture of HUVEC to better maintain cell viability and promote cell growth,so as to achieve the purpose of enhancing the adhesion of HUVEC on the surface of the decellularized valve.Therefore,the second step of this article explores the influence of hydrogel concentration on the behavior of HUVEC coated in GelMA hydrogel.In this paper,three concentrations of GelMA hydrogel were used to coat HUVEC to test the distribution,proliferation,activity and morphology of HUVEC in different concentrations of GelMA hydrogel.The results showed that the HUVEC coated in GelMA hydrogels of different concentrations were uniformly distributed in a three-dimensional manner inside the GelMA hydrogel,and maintained good cell viability.At the same time,the higher the concentration of GelMA hydrogel,the faster the cell proliferation rate.However,due to the tight cross-linked network structure inside the GelMA hydrogel,the cells are difficult to diffuse in a short period of time,and they are distributed in a round shape agglomerated inside the hydrogel.At the same time,the higher the concentration of GelMA hydrogel,the longer the cells will be restrained.(3)In order to enhance the binding force between the cells and the decellularized valve scaffold,this article proposes a method of inducing cells to migrate inside the decellularized valve,and promotes the cells to be distributed in a "I" shape on the decellularized valve,so as to achieve cell fixation.Purpose on decellularized valves.In order to achieve this goal,in the third step of this article,the surface of the decellularized valve is first subjected to acupuncture treatment,and then combined with the GelMA hydrogel coated with HUVEC to construct a GelMA hydrogel/needled decellularized valve composite scaffold and explore the effect of hydrogel concentration on the performance of GelMA hydrogel/acupuncture acellular valve composite scaffold.The results show that the surface of the decellularized valve after acupuncture treatment has large holes,and it can be combined with the GelMA hydrogel coated with HUVEC.At the same time,HUVEC showed good cell activity on the GelMA hydrogel/acupuncture decellularized valve composite scaffold at each concentration.However,only on the 5 wt% GelMA hydrogel/needle decellularized valve composite scaffold,within two weeks,a large number of cells in the gel layer adhered to the surface of the valve,while at 7.5wt% and 10 wt% On the GelMA hydrogel/acupuncture-treated decellularized heart valve composite scaffold,almost no cells were observed on the surface of the valve.However,for the5 wt% GelMA hydrogel/acupuncture-treated decellularized heart valve composite scaffold,there are still some defects.In two weeks,although a large number of cells adhere to the surface of the valve,the cells on the surface of the valve are not.Migrate along the surface of the hole to the inside of the valve.Therefore,within two weeks,the purpose of inducing cells to migrate inside the decellularized valve may not be achieved,and it may need to be cultured for a longer period of time before the cells in the GelMA hydrogel can be combined with the needled decellularized valve.Grows along the hole into the heart valve.