Preparation and characterization of composite delivery system of paclitaxel-loaded temperature sensitive liposome and siRNA-loaded gold nanostar

We prepared gold nanostar(GNS)through seed growth method firstly, then formation of COX-2 siRNA(siCOX-2)and GNS composite modified with polyethylene glyco(PEG), 2-amino-2-deoxy-D-glucos(DG)and 9-D-arginin(9R)was prepared. Afterwords, paclitaxel temperature sensitive liposome(PTX-TSL)was prepared by film dispersion method. Finally, siCOX-2 delivery systerm(PTX-TSL-(siCOX-2(9R/DG-GNS)))was obtained by hydrosulfuryl ligand reaction between siCOX-2(9R/DG-GNS)and PTX-TSL. The successful build of siCOX-2(9R/DG-GNS)was vetified by nuclear magnetic resonance(NMR), sodium dodecyl sulfate polyacryl amide gel electrophoresis(SDS-PAGE), and ultraviolet spectrophotometry and agarose gel electrophoresis method. Particle size of PTX-TSL-(siCOX-2(9R/DG-GNS))was(292±14)nm and Zeta potential was about -(2. 59±0. 12)mV, which were measured by Zetasizer Nano ZS90. The morphology of PTX-TSL-(siCOX-2(9R/DG-GNS))measured by transmissionelectronmicroscopy showed homogeneous star structure with phospholipid bilayer on the surface, and it showed good thermal conversion efficiency under radiation of 808 nm laser. Differential scanning calorimetry test showed that PTX-TSL phase transition temperature is about 42. 6 °C. The drug loading content(using dialysis method)and encapsulation efficiency of PTX-TSL were about 7. 5% and 95. 4%, at the same time, the release process experiment of PTX-TSL showed that it had a good temperature sensitive release performance. It is hopeful that this siCOX-2 system can be used for reducing drug resistance of PTX and improving the treatment effect of PTX through the synergistic antitumor drug resistance effect of siCOX-2.