The Construction And Biological Activity Of Hyaluronic Acid-Polyamine Targeted Polysaccharide Gene Carrier

Gene therapy has shown great potential in the treatment of cancer,AIDS,diabetes and other diseases.The key to the success of gene therapy is to prepare safe and efficient vectors to deliver genes to target sites.Cureently,the construction of gene vectors faces challenges such as poor water solubility,high toxicity,and complicated preparation procedure.In this thesis,a novel targeted gene carrier based on hyaluronic acid（HA）is constructed through supramolecular host-guest interactions,and a simple module assembly method for constructing gene carrier is developed.The contents are as follows:（1）The construction of HA-ADA/TEPA-CD and its performance characterization:tetraethylenepentamine（TEPA）and adamantane（ADA）were modified to cyclodextrin（CD）and hyaluronic acid（HA）via covalent bonds,respectively.And then the spherical nanoparticles with a shell of hyaluronic acid was constructed via host-guest interaction between CD and ADA.The size of the nanoassembly is about 100 nm and the surface potential is-17.5 m V.The nanoassembly shows excellent stability,with a critical aggregation concentration of 6μ mol/L.The agarose gel electrophoresis experiment and Tyndall effect results show that the nanoassembly can completely condense p DNA at N/P=80,and can effectively release p DNA in response to hyaluronidase.The gene transfection ability of the nanoassembly is similar to the commercially available transfection reagent,polyethyleneimine(PEI_25k),but the cytotoxicity is much less than PEI_25k.When the concentration up to 1 mmol/L,the relative cell viability is still higher than 80%.（2）The construction of HA-CD/PEI-ADA and its performance characterization:CD and ADA were modified to HA and PEI_25k through amide condensation reaction,respectively.And then the spherical nanoparticle with a shell of hyaluronic acid was constructed via host-guest interaction between CD and ADA.The size of the nanoassembly is about 300 nm and the surface potential is-18 m V.The agarose gel electrophoresis experiment show that the nanoassembly can completely condense p DNA at N/P=16.Compared with PEI_25k,the biocompatibility of supramolecular assembly has been significantly improved.When the concentration up to 2 mmol/L,the relative cell viability is more than 80%,but the gene transfection efficiency is not decreased.（3）Module assembly method:the high-efficiency and low-toxicity gene carrier with a shell of hyaluronic acid was constructed by simply mixing the aqueous solutions of cationic polymer-modified-cyclodextrin and adamantane-modified-hyaluronic acid together,which are used as building modules.