Preparation And Properties Of Borated Chitosan/guar Antibacterial Composites

As a kind of medical dressings with many excellent properties,chitosan-based materials have been widely used in clinic.Chitosan-based dressings not only have high water absorption and water vapor permeability,but also can resist the invasion of bacteria and other microorganisms and promote wound tissue rapid healing.This article was based on sponge and film two common medical dressings,mainly focused on the preparation and properties of borated chitosan/guar gum materials.The specific research contents and results are summarized as follows:1.Preparation of new guar chitosan/gum sponge by freeze-drying method(CS/GG sponge).The molecular structure and cross-sectional morphology of CS/GG sponge were characterized by Fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).The effects of dilute acetic acid concentration,glycerol dosage and CS: GG on the basic properties(water absorption,water retention and air permeability)of CS/GG sponge were studied.Antimicrobial test of CS/GG sponge was carried out by using agar plate diffusion method.The inhibition zones of CS/GG sponge on E.coli and S.aureus were 2.5 mm and 1.1 mm.2.The mixture of boric acid and glycerin was added into the mixture of chitosan gel and guar to form a homogeneous mixture system.After pre-freezing and freeze-drying methods,the boronated chitosan/guar gum sponge(B-CS/GG sponge)was prepared.The macromolecular structure of B-CS/GG sponge was characterized by FT-IR and SEM.BCS/GG sponge had good forming and more uniform internal porosity as hydrogen bond,coordination and other interactions were formed.The optimum conditions of preparation of B-CS/GG sponge were determined by studying the effect of CS:GG,the amount of glycerol,the amount of boric acid and freeze-drying time on sponge performance.Result of antibacterial test showed that B-CS/GG sponge had good antibacterial activity against both E.coli and S.aureus with the antibacterial inhibition zones of 5.5 mm and 2.9 mm respectively.3.Boronated chitosan/guar gum film(B-CS/GG film)was prepared with mixed system of guar gum,chitosan,glycerol and boric acid.The surface morphology of BCS/GG film was characterized by SEM and found the film was of good film-forming abilities,with smooth surface and uniform thickness.B-CS/GG films were prepared by changing the concentration of dilute acetic acid,the ratio of CS and GG,the amount of glycerol and the amount of boric acid respectively.The water absorption and breaking strength were tested to confirm the optimum preparation conditions of B-CS/GG film.The antimicrobial test showed that B-CS/GG membrane had an inhibition band width of 2.6 mm against E.coli,and 2.3 mm against S.aureus.