Preparation And Characterization Of Carboxymethyl Cellulose/chitosan Drug Loading Composite Materials

Cellulose is the most abundant and widespread polysaccharide substance in nature.Carboxymethyl cellulose is derivative of cellulose after carboxy methylation,and its chemical structure retain the characteristics of cellulose containing quantity of free carboxyl groups,which can form ionic bonds with other positively charged polymers in aqueous solution.Due to its molecular structure,carboxymethyl cellulose can improve its mechanical properties of composites.Chitosan is the derivative of chitin,which is more than 55% deacetylation.Chitin is the second abundant polysaccharide in nature,mainly derived from marine organisms such as shrimp and crab.Chitosan is a hot material in the field of materials research in recent years.It has the characteristics of non-toxic and harmless,environmental friendly,abundant and stable property,and it has good film performance and certain bacteriostatic effect,widely used in medicine,agriculture,industry,environmental protection and other fields.To investigate the structure-function relationship of carboxymethyl cellulose /chitosan composite material,different CMC/Chitosan ratios,pH conditions,glycerin content and drying condition for samples were prepared.Details of the properties and functions of the CMC/Chitsan composites were studied.The molecule interaction between the polymers was investigated by Fourier transform infrared(FTIR),which shows that the ionic bonds between carboxymethyl cellulose and the chitosan are stronger when the pH is alkaline.Conversely,when the environment tends to be acidic,the presence of hydrogen ions can destroy the interaction between the two molecules.It can be concluded from TGA that the existence of such intermolecular forces can weaken the force between the same molecules and their own,and weaken their thermal stability.From SEM graphs,the microstructure differences between membrane and sponge were compared.In the experiment of mechanical properties,the mechanical properties of the membrane were superior to that of the composite sponge,and the tensile strength was up to 57.5 Mpa and the breaking elongation was 88%.Compared with membrane morphology,the composite sponge has an excellent swelling performance,with a maximum swelling rate of 1224%(w/w.)After comprehensive consideration,the composite sponge was selected as the next study.Through the drug release experiment of ibuprofen and roxithromycin,it is known that the accumulating releasing of the drug is related to the swelling properties of the composite sponge.In the releasing of gentamicin,it was found that there was some bond between the gentamicin and the sponge matrix,which caused the increasing loading capacity for gentamycin of the sponge,especially for the sponge made in condition of pH=1.Releasing is also influenced by changing of pH condition.In the experiment of bacteriostatic performance,it was found that the composite material itself had certain antibacterial properties.After loading with gentamicin,antibacterial properties of sponges were greatly improved,and the diameter of antibacterial ring reached 4.96 mm,which increased by 204% compared with the control group.