Research On Preparation And Performance Of Polysaccharid Hydrogel Dressing

Dressing is a kind of temporary medical material which is used to cover the wound. Its main function is to control the exudate from the wound and protect it. What’s more, dressing can provide a conducive environment for wound healing and prevent the bacterial contamination and dust particles from the wound. When there is a large area of skin torn away or wound which needs a long time to heal, the surface coverage of wound dressing is extremely important.Hydrogel medical dressing is a new wound dressing developed in recent years. It has admirable water absorption and retention property. Hydrogels will not stick wound after absorbing exudate, which can reduce secondary damage during changing the dressing. Furthermore, it can incorporate some drugs during the process of production, which can be released slowly locally around wound in order to achieve topical antimicrobial function.The purpose of this thesis is to prepare polysaccharide hydrogel medical dressing with sustained releasing and antibacterial properties. The preparation of hydrogel dressing has three main procedures:1, Prepare oxidized carboxymethyl cellulose by chemical modification, and then prepare hydrogel by Schiff base reaction between oxidized carboxymethyl cellulose and carboxymethyl chitosan.2, Prepare carboxymethyl chitosan microspheres by emulsion crosslinking method with tetracycline hydrochloride embedded in.3, Compound the microspheres and hydrogels to prepare composite hydrogel dressing.We optimized the experimental parameters to improve properties of the hydrogel. The composite hydrogel dressing is amber, translucent, gelatinous, and has excellent mechanical properties, such as wonderful water absorption, slow degradation and drug sustained release. The hydrogel internal structure is spongy porous oberserved by SEM. Microspheres are uniformly distributed in the holes’wall or semi-embedded in the walls. At the same time, this dressing has good elasticity. When the compressive strain is 0.7(mm/mm), the tangent elastic modulus is up to 1.7MPa. As a result, when it is in the swelling balance, the degree of swelling of the hydrogel dressing is 4000%. The degradation time in vitro is about 7d-10d, and its drug sustained release performance is significantly better than the drug directly embedded in hydrogel, because it can release sustainedly and stably within 12 h, without obvious burst release phenomenon.We have not use toxic chemicals during the preparation of composite hydrogel dressing. In addition, the polysaccharide materials we used have no biological toxicity. The composite dressing is proved to be equipped with significant characterization of favorable mechanical properties, swelling function, degradation properties, and sustained release. Thus the polysaccharide hydrogel medical dressing is expected to get a good application in the wound dressing.