Study On Konjac Glucomannan/Graphene Oxide Drug Delivery Carriers

Konjac glucomannan(KGM)is a natural polymer with good gelation,water solubility and biocompatibility.It can only be degraded in colon after entering human digestive system.Graphene oxide(GO)is the oxidizing derivative of graphene,which contains a large specific surface area.There are abundant oxygen-containing functional groups such as carboxyl(COOH),hydroxyl(-OH)and epoxide(C-O-C)on the surface and edge of graphene oxide.The two masks have aromatic structures and can be conjugated by non-covalent interaction,such as π-π conjugation,hydrogen bonds and hydrophobic forces bind to the molecules containing aromatic rings,but related studies have shown that GO is prone to agglomeration in physiological environment when it is used as drug carrier.In this study,KGM and GO were used as the main raw materials.Three kinds of carrier materials based on KGM and GO were designed,and ciprofloxacin(CPFX)was used as model drug.The aim of this study was to make full use of the good biocompatibility of KGM and the interaction between GO and CPFX,and to develop KGM/GO carriers with good controlled release effect and enhance the bioavailability of CPFX.The main contents and results of this paper are as follows:1.KGM hydrogels had been widely used in food and medical industry,but their physical and mechanical properties need further improvement.KGM hydrogels were prepared by freeze-thawing deacetylated KGM sols.GO was introduced into the preparation process to enhance the function and properties of KGM hydrogels.Rheological tests showed that there was an obvious interaction between GO and deacetylated KGM.The results of characterization of KGM/GO hydrogels showed that there was obvious hydrogen-bond interaction between GO and KGM molecules.The successful introduction of GO resulted in better thermal stability and more compact network of KGM/GO hydrogel.KGM/GO hydrogels in deionized water and PBS 7.2 showed better swelling properties.Moreover,GO could obviously enhance the CPFX loading efficiency of KGM hydrogels.CPFX loaded KGM/GO hydrogels showed different release effect in different midiums,and the release rate of CPFX could be effectively slowed down by the introduction of GO in KGM hydrogels.KGM/GO hydrogels with enhanced properties showed great potential in drug carrier application.2.Microspheres were a kind of common carrier materials.Using CaCl2 solution as stationary solution,the size controllable KGM/SA(sodium alginate)/GO microspheres were prepared by highvoltage electrostatic assisted sharp pore coagulation bath.Chitosan(CS)film was coated on the surface of the microspheres though electrostatic interaction and glutaraldehyde crosslinking to enhance the stability of the KGM/SA/GO microspheres.Results showed that the size of the microspheres could be effective controlled by voltage.However,too high voltage will lead to uneven size of microspheres and incomplete spherical structure.The introduction of CS film could make the surface of microspheres smooth,and there was no obvious gully in microspheres.GO could enhance the interaction between KGM and SA.The swelling test showed that the microspheres exhibit different swelling properties in different media.The introduction of CS membrane showed significant effect on the stability of microspheres in simulated intestinal fluid(SIF)and simulated colon fluid(SCF).Meanwhile,the introduction of GO could greatly enhance CPFX loading efficiency of the microspheres,and finally control the release of CPFX.3.In recent years,nanofiber films had been widely used in tissue scaffolds,food packaging and other fields.CPFX loaded KGM/PAN/GO nanofiber films were prepared by opposite electrospinning technology,GO was loaded on polyacrylonitrile(PAN)and CPFX was loaded on KGM in preparation.Results showed that the nanofiber films contained spatial network structure which containing numerous nano-cavities consisting of a random distribution of nanofibers.The diameters of nanofibers ranged from 160 to 360 nm.There were obvious interactions between the components in nanofiber films.GO and CPFX showed significant influence on the chemical structure of nanofiber films.Moreover,XPS results confirmed that CPFX was successfully introduced into nanofiber films with KGM.Tensile tests showed that CPFX could enhance the mechanical properties of PAN/KGM/GO nanofiber film.This could be attributed to the strong hydrogen-bond interaction between GO and KGM,and π-π conjugation between GO and CPFX.PAN/KGM/GO/CPFX nanofiber films showed effective inhibitory effect on Salmonella(CICC21482)and Staphylococcus aureus(AICC10787),and with great potential in bandages and dressings application.