Research On Application Of Hyaluronic Acid Hydrogel In Biological Detection And Osteogenic Induction

As a natural polysaccharide hydrogel,hyaluronic acid hydrogel has been increasingly used in biological testing and tissue engineering due to its good biocompatibility and biological regulation function.However,the hydrogel obtained by natural separation still has defects such as insufficient mechanical properties and slow gel forming speed.In this thesis,starting from hyaluronic acid derivatives,a hydrogel system with rapid gel forming ability is prepared.On the one hand,the hyaluronic acid derivatives are combined with biological probes to construct biosensors based on hyaluronic acid hydrogel;On the one hand,the application of hyaluronic acid hydrogel as a cell culture substrate in promoting bone differentiation has been explored.Specifically,it mainly includes the following aspects:(1)A hydrogel material based on polymerization and cross-linking of hyaluronic acid derivatives was designed and synthesized,and its properties were characterized.As hyaluronic acid derivatives,HA-ADH and HA-CHO were gained by modifying the hyaluronic acid molecule with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and sodium periodate respectively,which have multiple sites that can be easily modified.The hyaluronic acid hydrogel obtained by mixing the two derivatives has fast cross-linking speed,the colloid is homogeneous and presents a loose and porous three-dimensional scaffold structure.Meanwhile,hyaluronic acid hydrogel exhibits high hydroscopicity and excellent biocompatibility,showing a good application prospect.(2)A glucose response sensor was constructed by combining a hyaluronic acid hydrogel with a biological probe based on fluorescence resonance energy transfer.Hyaluronic acid hydrogel microspheres coated with glucose fluorescent probe were prepared by phacoemulsification.The hydrogel microspheres can accurately respond to the glucose level of the sample by detecting the change in fluorescence intensity of microspheres at 620 nm,and also have excellent anti-interference ability and long-term stable fluorescence response.Meanwhile,the test results of hydrogel microspheres are in good agreement with the clinical standard results,indicating its good practicability.(3)Fluorescence donors(FITC)and fluorescence acceptors(AuNPs)based on fluorescence resonance energy transfer technology were coupled with two hyaluronic acid derivatives HA-ADH and HA-CHO,respectively.The prepared hydrogels can achieve specific fluorescent response to hyaluronidase,which has the advantages of high response sensitivity,wide response range,and good signal stability compared with traditional methods.More importantly,this method has good biocompatibility.When it is applied to three-dimensional culture of tumor cells,it can generate a fluorescent response to hyaluronidase secreted by the cells,showing the application potential of monitoring the secretion level of cellular hyaluronidase in situ.(4)Hyaluronic acid hydrogel is used to construct a layer of matrix material on the cell culture plate to induce osteogenic differentiation of osteoblasts MC3T3-E1.Cells grown on the hyaluronic acid hydrogel matrix showed a fiber morphology interwoven with spindle cells,while the cell growth morphology was more stereoscopic,and the cytoskeleton distribution was highly concentrated.This cell morphology is very similar to the cells in bone tissue.The expression of osteogenic differentiation-related genes and the activity of early osteogenic differentiation markers in cells were significantly increased,while the accumulation of calcified nodules also appeared in cells.This phenomenon may be regulated by stimulating cell adhesion-related genes through the special morphology and material properties of the hydrogel matrix.In addition,as the main cellular receptor of the hyaluronic acid molecule,CD44 also plays an important regulatory function.In summary,the hyaluronic acid derivatives and hydrogels prepared in this experiment can be used in biological detection and bone tissue repair,and show good stability,biocompatibility and anti-interference characteristics.It has laid a foundation for the development of future detection methods and the research of osteoinductive matrix.