The invention particularly discloses an intelligent targeting and environmental dual-responsibility siRNA [short interfering
RNA (ribonucleic acid)]
delivery system for tumor, a preparation method and application. The siRNA
delivery system is characterized in that siRNA is concentrated and compounded in
nanometer particle nucleuses by the aid of acid-sensitive amphiphilic three-block polymers, and intermolecular disulfide bonds are formed by PAsp(MEA) on sub-surfaces, so that the siRNA can be protected, and the intelligent targeting and environmental dual-responsibility siRNA
delivery system can respond to release of the siRNA in reductive
cytoplasm. The acid-sensitive amphiphilic three-block polymers comprise
polyethylene glycol block-intermediate block-acid-sensitive block three-block copolymers, intermediate blocks comprise polyaspartate acyl mercaptoethylamine, and acid-sensitive blocks comprise poly (diisopropyl amine) ethyl
methacrylate. The intelligent targeting and environmental dual-responsibility siRNA delivery
system, the preparation method and the application have the advantages that the siRNA delivery
system can be applied to preparing intelligent targeting siRNA nanometer medicines for the tumor and is low in N / P ratio dependence degree, and the siRNA can be quickly and completely released at targets; a novel idea can be provided for
gene delivery systems, and the intelligent targeting and environmental dual-responsibility siRNA delivery
system, the preparation method and the application have important significance on preparing
clinical diagnosis and treatment medicines for the tumor.