Research On Preparation And Performance Of Serotonin-modified Sodium Alginate Hydrogel

Skin wound healing has always been a difficult problem in the medical field.Due to its special biochemical and mechanical properties,hydrogels have broad application prospects in the field of wound dressings.This paper combined the advantages of sodium alginate（SA）and serotonin in hemostasis and wound healing,as well as the physical shielding effect of the complex network structure of hydrogels.Sodium alginate-serotonin（SAS）polymer was prepared by substitution reaction,using sodium alginate and serotonin as raw materials,and sodium alginate-serotonin was characterized by Fourier transform infrared spectroscopy and Ultraviolet-visible absorption spectra.Based on SAS polymer,two hydrogels were prepared.The properties of the obtained hydrogels were studied,and the following results were obtained.SAS polymers formed SAS hydrogels under the catalysis of the horseradish peroxidase and H2O2,The effects of H₂O₂concentration on its gel time,swelling degree and mechanical properties were studied by experiments,and the results show that the SAS hydrogels formed under different H₂O₂ concentrations（10 mmol/L～40 mmol/L）show good swelling degree（18g/g～33g/g）,short gel time（38s～80s）;the gel time,swelling degree and mechanical properties can be adjusted by changing the concentration of H₂O₂;Temperature and viscosity experiments show that the structure of the SAS hydrogel is stable in the range of 25～45°C;The water contact Angle show that the SAS hydrogel formed under the conditions of H₂O₂concentration of20mmol/L and horseradish peroxidase concentration of 0.3mg/m L has relatively suitable cell adhesion;The results of scanning electron microscopy show that the SAS hydrogel has three dimensional porous structure.Skin adhesion experiments show that the SAS hydrogel has good skin adhesion ability,and the skin adhesion performance increase with the increase of time within 30min.Meanwhile,the SAS hydrogel is easy to fall off the skin after drying.On the basis of the SAS hydrogel,in order to improve the mechanical properties,biocompatibility,and faster gelation rate and hemostatic performance of the hydrogel,Ca²⁺was introduced to synthesize SAS-Ca²⁺double crosslinked hydrogels(0.1mol/LCa²⁺).The effect of H₂O₂concentration（10 mmol/L～40 mmol/L）on its gel time,swelling degree and mechanical properties of SAS-Ca²⁺double crosslinked hydrogels was studied experimentally.The results show that the gel time is not affected by the concentration of H₂O₂,and the gel time is very short（within 10s）,the swelling degree decreases with the increase of H₂O₂ concentration,and the mechanical properties increase with the increase of H₂O₂ concentration;Temperature and viscosity experiments show that the structure of SAS-Ca²⁺double crosslinked hydrogels is stable in the range of 25～45°C;The water contact Angle shows that the SAS-Ca²⁺double crosslinked hydrogel formed under the conditions of 0.1mol/L Ca²⁺,20mmol/L H₂O₂ and0.3mg/m L horseradish peroxidase has suitable cell adhesion;Skin adhesion experiments show that SAS-Ca²⁺double crosslinked hydrogels has good skin adhesion ability and is easy to fall off the skin after drying.The SAS-Ca²⁺double crosslinked hydrogel and SAS hydrogels were compared in terms of gel time,mechanical properties,swelling degree,adhesion and degradation ability.The results show that the presence of Ca²⁺would accelerate the gel time of SAS hydrogels,SAS hydrogels show higher elastic modulus in the presence of Ca²⁺;The tensile properties of SAS hydrogels are mainly affected by the horseradish peroxidase and H₂O₂ catalyzed cross-linking,Compared with the pure ionic cross-linking,the hydrogels formed by the horseradish peroxidase and H₂O₂ catalyzed cross-linking has higher tensile strength;Ca²⁺cross-linked SAS hydrogels do not excessively prolong the degradation time of SAS hydrogels.