Fabrication Of Multifunctional Hydrogels Based On Chondroitin Sulfate And Their Application As Bioadhesives

Bioadhesives are a natural or synthetic material that can be utilized to soft tissue repair,wound healing,prevention of leakage of biological fluids and hemostasis,and can be used as a perfect replacement for sutures,nails and other mechanical suturing means.However,bioadhesives reported at this stage are often easily damaged by liquid or gas after being damaged by the adhesive,and the various irregular wounds are not well adhered and filled.Because the adhesive completes its function or in special cases,it has to be removed in time.And because of its strong adhesion,directly peeling off the adhesive easily causes secondary damage to the tissue and remains.Reversible adhesion allows the bioadhesive to switch between the adhesive and the non-adhesive,thereby being painlessly peeled from the wound tissue.Most commercial adhesives often was just one of the effects of hemostasis,tissue bonding and sealing,which greatly limits their application.This paper is based on the natural polysaccharide of chondroitin sulfate to prepare different multifunctional hydrogels,which have strong adhesion,self-healing,injectable and reversible adhesion.In addition,the developed multi-functional hydrogel also combines hemostasis,tissue bonding and sealing.Specific article contents are as follows:1.Preparation and properties of chondroitin sulfate/Fe³⁺supramolecular hydrogelIn this study,we developed a facile approach based on dynamic metal-ligand coordination chemistry between chondroitin sulfate（CS）and Fe³⁺in the design and synthesis of a novel multifunctional metallohydrogel bioadhesives.This CS-based hydrogel not only have strong tissue adhesion superior to that of commercial fibrin glue,but also exhibited an excellent self-healing ability and injectability,which are beneficial in the field of bioadhesives.Moreover,the hydrogels underwent a rapid gel–sol transformation in response to multiple external stimuli,including pH,ions,neutral molecules and chemical redox reactions for reversible adhesion purposes,and enabling the rapid removal of the bioadhesive.In addition,metallohydrogel are rapidly formed within 10s,quick enough to promptly seal the tissue.Importantly,the multifunctional CS-based bioadhesives exhibited good biocompatibility,thus allow the developed materials to meet key requirements for next generation tissue adhesives.2.Preparation of gelatin-oxidized chondroitin sulfate multi-functional hydrogel and its application in bioadhesivesIn this paper,chondroitin sulfate（CS）is oxidized to oxidized chondroitin sulfate（OCS）with aldehyde group by sodium periodate,and borax and OCS chain are further introduced to produce boric acid-diol complex to increase the yield of OCS,and then The amino group on the gelatin forms a hydrogel in situ by a Schiff base reaction.Gel-OCS hydrogels also have good self-healing and injectability owing to the large number of reversible covalent and non-covalent bonds.In addition,both gelatin and chondroitin sulfate have many functional groups acting on the tissue.And the aldehyde group contained in the hydrogel can be further covalently bonded to the amino group on the tissue based on the Schiff base reaction,thereby having strong adhesion to the tissue.Hydrogels also have dynamic temperature-responsive properties that form hydrogen bonds with the tissue-acting groups at low temperatures to reduce adhesion and reversible adhesion,thereby achieving rapid exfoliation.Hydrogel has good cell compatibility and in vitro and in vivo degradability,and has been proved by animal experiments to have various uses for hemostasis,wound sealing and adhesive tissue.The versatility of this hydrogel makes it meet the key performance requirements of the new reversible adhesive bioadhesives and has important application prospects in the biomedical field.