Preparation And Study Of Two-component Hydrogel Based On Oxidized Hydroxyethyl Starch And Aminated Carboxymethyl Chitosan

In recent years,the application of hydrogel in the fields of tissue engineering and clinical medicine has gradually become the focus of attention.Because of its high water content inside the hydrogel and its physical properties similar to the extracellular matrix(ECM),it can mimic the structure of tissue in human body,so it can be widely used in tissue engineering repair materials.By modifying the natural materials,the hydrogel formed by the Schiff base reaction mechanism has the characteristics of mild reaction conditions,short gelation time,and wide source of raw materials.In this experiment,we used the strong oxidizing properties of sodium periodate in order to introduce more aldehyde-based active sites into hydroxyethyl starch.It could identify the o-hydroxyl structure,sites oxidative cleavage and form aldehydes.In order to introduce more amino active sites in carboxymethyl chitosan,we chose to use anhydrous ethylenediamine reagent.It could combine with carboxyl groups,and produce an amide structure when carbodiimide hydrochloride was used as a catalyst to activate a carboxyl group.When an aldehyde group was combined with an amino group,hydrogel were produced by schiff base reaction.After successful completion of the hydrogel,the performance of the prepared hydrogel was evaluated in various aspects.By measuring the successful introduction efficiency of the aldehyde group content in the hydroformylation,the results showed that the oxidation efficiency of the hydroxyl group in the polysaccharide reaches the highest when the molar ratio of oxidant to hydroxyethyl starch reaches 2:1.By measuring the grafting efficiency of the amino group content in the amination,the results showed that the grafting efficiency of the amino group is optimal when the molar ratio of the aminating agent to the carboxyl group is 20:1.By measuring the curing time of the hydrogel,the results showed that the hydrogel prepared by the experiment can be cured in a shorter time.In addition,the expansion ratio of the hydrogel in aqueous solution was also characterized in the experiment,which proved that the hydrogel absorbed moisture expansion would exceed 40% of the dry weight of the hydrogel.By measuring the rate of in vitro consumption in a solution containing simulated tissue fluids,the experimental results showed that the hydrogel is completely depleted in the body fluid within 10 days.The pig skin which wasbonded using the hydrogel was measured the tensile strength by universal testing machine,the text date was indicating that the hydrogel possessed the characteristics of a bonded structure.Finally,this experiment carried out a simple evaluation of the biological properties of the hydrogel,and the results showed that the cell growth was better than the blank control group by using mouse fibroblasts on the surface of the hydrogel.Therefore,hydroxyethyl starch/carboxymethyl chitosan hydrogel had certain feasibility for skin adhesion in tissue engineering.