Prepared And Study Of Hydrogel Tissue Adhesive Based On Hyaluronic Acid And Polyphenol For Tissue Adhesion

Tissue adhesives provide a new method for wound closure and hemostasis,and their advantages over traditional methods such as sutures and staples in terms of ease of use,rapid closure and minimal tissue damage have made them widely recognized in clinical use.However,existing medical adhesives generally have the problem of poor adhesive strength.Hyaluronic acid is a polysaccharide that widely exists in animal body tissue.,Because of its good biocompatibility and abundant biological function,hyaluronic acid hydrogel tissue adhesives caused extensive concern of the researchers.However,hydrogel based on HA usually suffers from poor mechanical properties due to the HA’s excessive swelling and rapid degradation.To address this issue,this thesis constructs hyaluronic acid-tannic acid hydrogels based on hyaluronic acid and polyphenols for improving the strength of hyaluronic acid tissue adhesion,and hyaluronic acid-dopamine multifunctional hydrogels for tissue adhesion and antibacterial.The main research contents are as follows.The first part of the work in this thesis constructed hyaluronic acid-tannic acid(HT)high performance tissue adhesives through hyaluronic acid and tannic acid to achieve universal adhesion to different materials and underwater adhesion to tissues.By adjusting the amount of tannic acid,we obtained HT hydrogels with different mechanical properties,and by testing the tensile,compressive and rheological properties,we demonstrated the enhancement of the hydrogel mechanical properties by the formation of hydrogen bond crosslinks between hyaluronic acid and tannic acid.Then we investigated the tissue bonding properties of the hydrogels and found that different modulus hydrogels have different adhesion properties,with HT-8 adhesives achieving strong bonding to hard materials including steel and plastics,and HT-4 achieving strong bonding to soft tissues.We attribute the excellent adhesive performance to the fact that the hyaluronic acid backbone of the adhesive enhances the mechanical strength of the hydrogel body by forming hydrogen bonding crosslinks with tannic acid,and secondly,the interfacial bonding between the hydrogel and the tissue is enhanced by hydrogen bonding between tannic acid and the tissue and topological interlocking between the HT hydrogel adhesive and the tissue,which synergistically results in a strong tissue adhesion due to the simultaneous enhancement of the body strength and the interfacial adhesion.The synergistic effect of these two leads to a strong tissue bonding.Finally,we also investigated the mechanism and performance of the hydrogel adhesive for underwater tissue bonding based on the water absorption property of the adhesive.The presence of interfacial water is the main difficulty for the hydrogel to achieve underwater bonding,and HT hydrogel has good water absorption ability to absorb interfacial water during the underwater adhesion process.We found that the hydrogel has good underwater bonding ability and the mechanism and influencing factors of underwater bonding were discussed in detail.Based on the underwater bonding ability of this hydrogel,we investigated its application to different organ tissues for underwater bonding.The second part of the work in this thesis designs a hydrogel adhesive with photothermal antibacterial function.This work achieved both improved tissue adhesion properties and photothermal antibacterial function of hyaluronic acid adhesive by the introduction of dopamine and ferric ions.The aldehyde-based hyaluronic acid was first prepared by oxidation of sodium periodate,then dopamine was grafted onto the hyaluronic acid backbone by Schiff base reaction,and finally ferric ions were added to the system to form ligand bonds with dopamine to enhance cross-linking.Firstly,we obtained a series of hydrogels with good tissue adhesion properties and determined the specific formulations by testing the tissue bonding properties of the hydrogels.Then we investigated the effect of ferric ion addition on the mechanical and adhesive properties of the hydrogels,and in this part we found that the mechanical properties of the hydrogels increased and then decreased with the ferric ion content.Finally,we investigated the photothermal antimicrobial properties of the hydrogel and demonstrated that the addition of dopamine ferric ion complexes resulted in the excellent photothermal antimicrobial ability of the hydrogel.In this part,we achieved internal cross-linking of the network by functionalizing the hyaluronic acid backbone with dopamine and introducing ferric ion coordination,which improved the mechanical properties of the hydrogel body and also achieved strong tissue adhesion.In addition,the photothermal ability of the hydrogel was achieved by the coordination of ferric ions and dopamine and the good photothermal antibacterial property of the hydrogel was demonstrated by antibacterial experiments.In the first project,the mechanical properties of hyaluronic acid hydrogel were enhanced by adapting tannic acid to improve the tissue adhesion properties of the hydrogel,and the tissue adhesion mechanism and underwater tissue adhesion of the hydrogel were further investigated.In the second project,we prepared a photothermal antimicrobial hydrogel using aldehydic hyaluronic acid,ferric ions and dopamine to achieve good photothermal antimicrobial properties along with tissue adhesion.In summary,we have obtained two hydrogel adhesives by a simple synthetic method in this thesis,which provides a new construction idea and method for the preparation of hydrogel adhesives.