Preparation And Properties Of Chitosan-based Composite Gel Materials

Hydrogels are aggregates of hydrophilic polymers and water,and have a three-dimensional space that can absorb large amounts of water.A typical hydrogel contains more than 90%water.The material state of hydrogel is between liquid and solid,and it has viscoelasticity of solid and fluidity of liquid.Its morphology is similar to the extracellular matrix of living tissue and can be used as an ideal material in the field of biomedicine.Chitosan has attracted wide attention as an effective biopharmaceutical material in bone tissue engineering,especially because its hydrophilic?-OH?and hydrophobic?-NH₂?groups enhance its gradual degradation,cell compatibility and mucosal adhesion These characteristics have advantages in promoting bone remodeling and repair processes.This article is mainly based on chitosan/polyethylene glycol to prepare composite hydrogel,and study its physical and chemical properties and biocompatibility.?1?First,based on chitosan with excellent biocompatibility and polyethylene glycol with excellent biological safety,the two ends of polyethylene glycol are conjugated through a one-step esterification reaction to produce a double-ended benzaldehyde group.End-capped polyethylene glycol?DF-PEG?,and then the chitosan composite hydrogel was upgraded to form a cross-linked composite network through chitosan and polyethylene glycol modified product?DF-PEG?.By controlling the system ratio of each component,the system is doped with nanocrystalline hydroxyapatite?mineralized collagen nHAC?,the sol-gel transition is formed within 30±5s,and an injectable,Chitosan-based hydrogel.Through FT-IR and NMR characterization,the gel cross-linking agent polyethylene glycol was successfully conjugated with aldehyde groups at both ends.The chitosan-mineralized collagen hydrogel constructed based on Schiff base bonds has rapid gelation and has certain self-healing properties.Through rheological characterization,the hydrogel has shear thinning characteristics and good viscoelasticity.SEM shows that the pore structure of hydrogel is dense,with a continuous and stable three-dimensional network structure,which is conducive to cell adhesion and growth.The cell compatibility test results of the composite hydrogel show that the hydrogel has good biocompatibility and has potential application value in tissue engineering materials.?2?In this paper,the respective advantages of chitosan-based composite hydrogel and graphene are combined to develop a composite hydrogel with a hierarchical structure.The graphene material retains the injectable properties of the composite hydrogel while enhancing the mechanical properties.Characterization of rheology,crystallinity,swelling properties,micro-morphology and cell compatibility of composite hydrogels.Through the analysis results,the crosslinked chitosan graphene composite hydrogel was successfully prepared,and compared with the hydrogel without graphene material,the viscoelasticity of the hydrogel is improved,the swelling performance is improved,and it has good biocompatibility.?3?Graphene oxide?GO?is very promising in regenerating cartilage,bone,skin and nerve tissue.In this paper,a composite hydrogel containing GO was prepared by chemical cross-linking method using chitosan and polyethylene glycol.The compound hydrogel research results show that the compound hydrogel has good self-healing and biocompatibility,and is expected to be used as an injectable material in tissue engineering.