Construction And Biological Evaluation Of Multi-Modification Hollow Mesoporous Organosilica-Doxorubicin Nano-Drug Delivery System

As one of the traditional chemotherapy drugs for cancer treatment,doxorubicin（DOX）is limited in clinical application because of its side effects such as cardiotoxicity.Due to its high biocompatibility and easy modification,mesoporous silica-based nanoparticles have been used as the delivery carrier of traditional chemotherapeutic drugs to construct nano-drug delivery system has gradually become a hot spot in recent years.Objective:In this study,hollow mesoporous organosilica nanoparticles were used as drug carriers and DOX was used as model drugs to construct a Polo-like kinase 1（PLK1）-targeted pH and redox dual-responsive drug delivery systems.The aim is to improve the anti-tumor efficacy and reduce the side effects of traditional chemotherapy drugs such as DOX,and provide new ideas for the research and development of new formulation of traditional chemotherapy drugs.Methods:（1）Using cetyltrimethylammonium chloride as template,tetraethyl orthosilicate and bis-[3-（triethoxysilyl）propyl]-disulfide as silicon sources,and triethanolamine regulating acid-base environment,hollow mesoporous organosilica nanoparticles（HMONs）,were synthesized by sol-gel method,and their morphological observation,pore size determination,elemental analysis,in vitro degradation behavior and cytotoxicity were studied.（2）The drug DOX was loaded into HMONs by electrostatic interaction,and the drug loading rate was determined by HPLC method.In a weakly alkaline environment,the polydopamine layer was coated with HMONs-DOX nanoparticles,and the phosphorylated peptides with PLK1-targeted were modified on the surface of the polydopamine layer by Schiff base/Michael addition reaction to prepare p Peptide-PDA@HMONs-DOX nanoparticles.The successful modification of polydopamine layer and phosphorylated peptides was verified by TEM,XPS,FT-IR and other characterization,and the degradation and release behavior in vitro were investigated.（3）The mice breast cancer 4T1 cells were selected for anti-tumor efficacy test of p Peptide-PDA@HMONs-DOX nanoparticles in vitro;rabbits were selected for hemolysis test and vascular irritation test in vitro to evaluate biocompatibility.Finally,Balb/c tumor-bearing mice model was used for anti-tumor effect test in vivo.Results:（1）The results of morphological observation and FT-IR showed that HMONs,had spherical and hollow structure.The results of SEM-EDS elemental analysis and XPS showed that disulfide bond was successfully incorporated into the framework of HMONs.The results of degradation test in vitro showed that HMONs had the characteristic of responsive degradation of GSH,and the cytotoxicity test showed that HMONs vector had low cytotoxicity at the experimental concentration.（2）The optimal drug loading rate of the nanoparticles prepared in the subject is 30.85±4.2%.The successful preparation of PDA@HMONs-DOX nanoparticles and p Peptide-PDA@HMONs-DOX nanoparticles was verified by a series of characterization.The degradation and release behavior in vitro showed that the p Peptide-PDA@HMONs-DOX nanoparticles drug loading system had the dual-stimul and responsive drug release properties of pH and GSH.（3）Hemolysis test showed that when the concentration of p Peptide PDA@HMONs-DOX nanoparticles was 240μg·m L^-1,there was no obvious hemolysis,and PDA@HMONs-DOX nanoparticles had no obvious vascular irritation.The results of in vitro efficacy test showed that p Peptide-PDA@HMONs-DOX nanoparticles had time and concentration dependent cytotoxicity to 4T1 cells.The anti-tumor efficacy test in vivo showed that the prepared p Peptide-PDA@HMONs-DOX nanoparticles had good biological safety,and its anti-tumor effect was significantly better than that of DOX raw materials.Conclusion:In this study,based on the advantages of high drug loading and high biocompatibility of HMONs,a PLK1 targeted pH/redox dual-response hollow mesoporous organosilica nano-drug delivery system was designed and prepared,which can significantly improve the anti-tumor efficacy of the antineoplastic drug DOX in vivo and in vitro and reduce its side effects.