Design And Synthesis Of Multi-Functional Drug Delivery Systems Based On Organic Silicon Nanoparticles

Cancer is the most ruthless killer to humans.Chemotherapy,one of the most important anti-tumor methods.However,there remain sevral factors which limit the efficacy of drugs,such as the drug resistance of tumor tissues and cells,the side effects of drugs and the unexpeced degradation in the body.So,the appropriated carriers were required to deliver the drugs to the tumor tissue effectively.Relevant researchs have shown that particles less than 120 nm in diameter are benefit for endocytosis.Based on this,the researchers studied and synthesized a variety of nanoparticles with specific functions and successfully loaded drugs,and constructed a variety of intelligent drug release systems(DDSs).In numerous nanoparticles,organic silicon nanoparticles are often selected as drug carriers due to their unique advantages,especially in the construction of multifunctional drug release systems.Besides,introduce functional organic groups into the framework or on the external surfaces of the nanoparticles,which can be used to design various mechanisms for stimuli-responsive.In addition,different types of drugs play different roles,such as mechanisms,stability,and toxicity,selectivity,also the release sites are not the same.Combined with multiple antitumor drugs,can effectively overcome the selectivity of single drug,greatly improve the utilization rate of drugs,and improve the anti-tumor effect.According to the above,we envisage using organic silicon nanoparticles as the template,simultaneously loading multiple anti-tumor drugs,to construct a multi-functional smart drug delivery system.Accordingly,we designed and constructed two multi-functional drug delivery systems:(1)pH-sensitive nanocomposite drug delivery system.Introduce the functional group C=N bond into the framwork of the organic silicon nanoparticles,at the same time encapsulate the macromolecular molecules and the micromolecle molecule drugs into the nanoparticles.In the acidic condition of the transitional expression of the tumor tissue,C=N bond fracture,the nanoparticles rupture and release the loaded drugs.Moreover,it has a fast degradation rate,which enables the drug to reach a higher concentration in a short period of time,with the synergistic effect of macromolecular drugs and small molecules,enhancing the anti-tumor effect.(2)Step release multi-functional nano drug delivery system.A multi-functional drug delivery system with core-shell structure was constructed which based on hollow mesoporous silicone nanopartcles.The drug delivery system load macromolecular drugs and micromolecule molecule drugs at the same time,which could release micromolecule drugs at the tumor tissue and biomacromolecule drugs into cancer cells stepwise.The micromolecule molecule drugs released in tumor due to excessive expression of acid stimulation and make the mesoporous channels open.Meanwhile the biomacromolecule drugs were held back by the selective mesoporous.After endocytosed into cells,with the excessive GSH concentration,the disulfide bonds were destroyed,causing the shells of the nanoparticles dissociated and the protected biomacromolecule drugs deliveried.