Preparation And Analysis Of Ang2-siRNA Plasmid Magnetic Chitosan Nanoparticles

Objective：The Ang2system is widely expressed in vascular system reconfiguration ofhuman tumors, but in normal tissue it is not expressed which make it an attractivecandidate target for an anti-angiogenic cancer therapy. Ang2-siRNA recombinantplasmid has been successfully constructed in our preliminary research results, withwhich transected into HUVECs could inhibit the expression of Ang2; we have furtherconstructed the Ang2-siRNA lentiviral expression vector, Infected with malignantmelanoma xenograft inhibit angiogenesis, growth. As a result the angiogenesis wassignificantly inhibited.Methods:1、Use chemical coprecipitation to prepare the nanoparticles of Fe3O4.2、Use emulsion crosslinking method to prepare magnetic chitosan nanoparticles3, Use transmission electron microscopy to observe the physical form of magneticchitosan nanoparticles.4、Use the laser particle size tester to detect the distribution of magnetic chitosannanoparticles.5、Do the experiment of the sedimentation of magnetic chitosan nanoparticles.6、Analysis the combination of the Ang2-siRNA plasmid expression vector andmagnetic chitosan nanoparticles.Results:1、The prepared magnetic Fe3O4nanoparticle which is dark brown granularpowder under the naked eye, has good magnetic responsiveness.2、 The prepared chitosan magnetic nanoparticles can be well dispersed in thedistilled water. It is dark brown suspension which has good magnetic responsiveness. It is shown as in the majority with oval and spherical particles under the transmissionelectron microscop, and a few is irregular shape. Particle size is about70nm andboundary. The range of the samples has a narrow particle size distributionwhiche is55.2~82.5nm and the average diameter is67nm.3、 The magnetic chitosan nanoparticles can move directional in the liquid underthe action of additional magnetic field.4、Ang2-siRNA plasmid chitosan magnetic nanoparticles were successfullyprepared.Conclusions：The successful preparation of the small particle size, narrow particle sizedistribution of Ang2-siRNA plasmid magnetic chitosan nanoparticles, which can bewell combied with Ang2-siRNA plasmid expression vector, provide the experimentalmaterials of the next step on the studies of Ang2-siRNA plasmid chitosan magneticnanoparticles targeted therapy of malignant melanoma in vivo and vitro.