Gellan Gum/graphene Oxide Composite Hydrogels:Synthesis,Characterization And Biomedical Applications

The development of biomedical materials with good biocompatibility,degradability,stability and multi-function is the focus of the development of contemporary biomaterials.In recent years,because of its unique rheological and gel properties,good biocompatibility and biodegradability,gellan gum(GG)had been widely used in the biomedical field.However,they often have poor mechanical properties and lack of cell sites,so their applications are limited in the biomedical field.Graphene oxide(GO)is safe and nontoxic.It has abundant functional groups on its surface and is widely used in the biomedical field such as drug delivery,cell carrier,bone tissue repair and so on.In this study,GG and GO were combined to develope a novel 3D bio-printing ink with good printability,mechanical strength and biocompatibility.Moreover,the controlled release property and anti-adhesion performance of GG/GO composite hydrogel were modified as functional scaffold materials.These have laid the experimental foundation for the medical applications of GG/GO composite hydrogel.In this study,based on the previous GG based 3D bio-printing ink developed by the research group,in order to improve the mechanical properties and function of GG,we introduced GO and developed a novel bio-ink for 3D bio-printing.After evaluating the rheological properties,printing properties,fidelities and mechanical strength of GG/GO composite hydrogel with different concentrations,the best precision ratio and printing conditions for human tissue organ printing was found.On this basis,the curcumin(Cur)was successfully loaded on surface of the GG/GO three-dimensional scaffold to prepare a bifunctional scaffold with anti-tumor and osteogenic properties.The vitro cell experiments showed that GG/GO/Cur scaffold could effectively kill osteosarcoma cell(MG-63)and promote the growth of osteoblast cell(MC3T3),which has a good application potential for the repair of bone tumor defects.In order to further expand the application of GG/GO biomaterials in biomedical field,we reduced GO successfully using the polydopamine(PDA)and coated PDA layer on the surface of the composite membrane.The modified GG/GO/PDA composite film has excellent mechanical properties,smooth surface,low roughness and strong hydrophobicity.The vitro cell experiments showed that the cells could not adhere well to the surface of GG/GO/PDA film,so it can be applicated potentially for anti-adhesion membrane.