Study On The Preparation Of Functional Hydrogel And Its Diagnostic Properties

As an excellent carrier,hydrogels are widely used.In particular,nano-sized hydrogels are widely used in the study of in vivo diagnosis and treatment.The existence of various active molecules in cells plays a certain role.The difference between normal cells and tumor cells is mainly reflected in the expression degree of these active molecules.Compared with normal cells,tumor cells also have a very special microenvironment,which provides conditions for intracellular detection.In this paper,three kinds of nanomaterials,including fluorescent nanoparticles,metal-based nanoparticles and hybrid nanogels,were designed and synthesized according to the existing reports and research situation.All of them showed good performance in vitro experiments,and the intracellular active sulfur and reactive oxygen molecules were detected by fluorescence imaging.The integration of intracellular diagnosis and treatment was realized The main contents of this paper are as follows:(1)Fluorescent polymer nanoparticles were prepared by hydrophobic self winding and hydrolysis of styrene maleic anhydride.Then,the fluorescent particles are loaded into the nanogels through the hydrogen bonding between the carboxyl group and the amino group.Fluorescent nanoparticles and water-swelling nanogels form a unique two-phase structure at the interface interaction.Fluorescence nanogels prepared based on this property have the effect of temperature induced fluorescence quenching and recovery.At the same time,hydrogen sulfide molecular detection system was built by virtue of fluorescence quenching recognition of fluorescent particles with iron ions.The strong interaction between sulfur ions and iron ions makes the fluorescence recovery.Fluorescence nanogel finally realized the detection and imaging of intracellular active sulfur molecules(2)Bare gold nanoparticles were prepared by sodium citrate reduction of auric chloride.Then,through the electrostatic interaction between the surface of gold nanoparticles and the amino group,the surface double bond was created to facilitate the further seed polymerization.Finally,the gold nanogels with core-shell structure were prepared.Gold nanoparticles are incorporated into the gel and provide catalytic properties similar to those of natural enzymes.The properties of catalase-like and glucosemimicking enzyme were proved by the experiment of chromogenic agent.Fluorescence imaging technology was further used to confirm that it can also decompose and catalyze endogenous reactive oxygen molecule-hydrogen peroxide in cells,so as to protect cells from oxidative stress damage caused by hydrogen peroxide.(3)Bare gold nanoparticles were prepared by sodium citrate reduction of auric chloride.Furthermore,through the surface deposition method of silver chloride in acidic environment,the surface anisotropic growth branching of gold particles was obtained and finally the Au Star nanoparticles with special morphology were obtained.Reduction of chloroplatinic acid by ascorbic acid further grows the platinum nanoparticles to their tip or surface.The surface gel shell was prepared by amidation reaction after the modification of the surface by gold-sulfur bond,and the bimetallic nanoparticles coated with nano-gel were finally obtained.As the core of the system,Au Star provides a good photothermal conversion ability,platinum nanoparticles of special size provide catalase properties,and the nanogel shell provides a place for the cross-linking load of natural glucose oxidase glutaraldehyde.Finally,the system realizes cascade reaction and further realizes intracellular collaborative therapy.(4)Finally,the morphology of the three different composite nanogels and their intracellular diagnosis and treatment effects were specifically characterized and analyzed,further intracellular diagnosis and treatment applications of the three nanomaterials were prospected based on the experimental results.