Study On Preparation And Performance Of Alginate-based Wound Dressings

Materials used to protect the surface of a patient’s skin wound is defined as medical dressings.The gauze we are familiar with is the earliest medical dressing,but it has a series of shortcomings such as non-antibacterial and single performance.Therefore,it is necessary to design new medical wound dressings to solve these problems.Material selection and morphological design are two mainly considered aspects during the development of the wound dressings.As a polymer material,sodium alginate has good physicochemical properties and satisfactory biological properties,such as biocompatibility,antibacterial activity and resistance to tissue adhesion.Various types of dressings such as films,sponges and hydrogels were prepared through chemical and physical crosslinked.However,the dressings prepared with sodium alginate as materials still have some performance and process defects,and further study of the improvements is of high significance.This paper mainly employs sodium alginate as the basic material to prepare three different types of medical wound dressings including two-dimensional medical dressing film,three-dimensional medical dressing sponge,and hydrogel,through the combination of chemical crosslinking(Schiff base conjugated crosslinking)and calcium ion crosslinking.In particular:(1)film preparation: a dense transparent film was obtained through a cast film-volatilization of sodium alginate(Alg),oxidized sodium alginate(OAlg),chitosan precipitation(CS).(2)Sponge preparation: a sponge having a three-dimensional pore structure was obtained by blending-lyophilizing OAlg and CS.(3)Hydrogel preparation:transparent and dense hydrogel was obtained by Schiff base conjugate crosslinking and ion crosslinking between Alg,OAlg and carboxymethyl chitosan(CMCS).Subsequently,study on the effects of different material mixing ratios and external additives on the properties of three medical dressings was conducted.Drug release,inhibition zone and cytotoxicity tests were performed.The results are as follows:(1)The film with CS/OAlg of 6:1 has excellent mechanical properties,good hydrophilicity,good water vapor transmission and swelling properties,and the degradation stability is good.(2)The sponge with a glycerin content of 2% is excellent in resilience,has good porosity,water vapor permeability and very good water absorption,and has good degradation stability.(3)The hydrogel with CMCS/Alg/OAlg of 3:1:1 has excellent mechanical properties,good rheological properties,proper gel time stability and good swelling properties,and good degradation stability.(4)The antibacterial drug slow-release test showed that the three kinds of medical dressings have a relatively fast antibacterial drug release.The antibacterial effect test showed that all three medical dressings have satisfactory antibacterial activity.The cytotoxicity test showed that the sodium alginate film has good biocompatibility.