Construction Of Metal-Phenolic Network Coated Hollow Mesoporous Zirconia Targeted Nano-Drug Delivery System And Cell Dynamics Study

As one of the most common primary tumors,liver cancer has a high incidence and low survival rate,so the treatment of liver cancer has become an important challenge.Doxorubicin hydrochloride（DOX）is used as a chemical drug for clinical treatment of cancer,while DOX,as a commonly used drug for cancer treatment,has many disadvantages,such as the distribution of antitumor drugs is not selective to cancer cells,which will cause serious side effects.Nano drug delivery systems allow controlled and accurate delivery of chemicals to cancer sites,minimizing side effects and improving drug efficacy.Hollow mesoporous zirconia nanoparticles（HMZN）with nanoparticles infused with hollow structure,easy surface modification and good biocompatibility have received widespread attention in drug delivery.Based on this,this paper prepared a hollow mesoporous zirconia targeted nano drug delivery system,which coated the surface of HMZN with a metal-phenolic network（MPN-La）formed after complexation of tannic acid（TA-La）modified by targeting molecule lactose（La）and Cu²⁺.A multi-functional drug delivery system with good targeting and biocompatibility（DOX@HMZN@MPN-La）was constructed and its cytotoxicity,uptake capacity and cytodynamics were investigated.This subject mainly performed the following experiments:（1）Firstly,hollow mesoporous zirconia nanoparticles were prepared using silica as template,and the antitumor drug adriamycin was loaded into the hollow mesoporous zirconia cavity.Secondly,tannic acid modified by lactose acid was coated on the surface of HMZN by complexing reaction with Cu²⁺,so as to construct an acid-sensitive and targeted drug delivery system.The particle size distribution and potential were characterized by laser particle size and Zeta potential analyzer,the morphology of nanoparticles was characterized by transmission electron microscopy（TEM）and scanning electron microscopy（SEM）,the functional group,specific surface area and pore size of nanoparticles were determined by Fourier transform infrared spectroscopy（FT-IR）,and the coating rate of surface modified molecules was determined by thermogravimetric analyzer,the production of hydroxyl radicals was also detected.The results show that:the particle size distribution of the prepared nanoparticles is uniform,the average hydration particle size of HMZN is 142.5 nm,the electric potential is-19.8 m V,the average hydration particle size of HMZN@MPN-La is 192.7 nm,the electric potential is-37.5m V,and all of them are spherical dispersion,and the obvious hollow structure can be seen.The specific surface area of HMZN was 276.399 m²/g,and the pore size was 3.199 nm.The metal-phenolic network structure was successfully coated on the surface of the nanocrystal,and the coating rate was about 9.7%.（2）The loading rate and encapsulation rate of doxorubicin nanoparticles were investigated.The loading rate and encapsulation rate of the nanoparticles were about 31.7%and 74.5%,indicating that the hollow structure of HMZN provided a large space for doxorubicin loading.In vitro drug release experiments,the metal-phenolic network structure（MPN-La）modified on the surface of HMZN can be degraded under acidic conditions,which is conducive to the dissociation of drugs from the cavity of drug-carrying nanoparticles.Therefore,the cumulative release rate of DOX in pH 5.0 release media was significantly higher than that in pH 7.4 and pH 6.0 release media.（3）The hemolysis of blank vector HMZN@MPN-La was evaluated by biocompatibility test,and the percentage of hemolysis was lower than 5%in the concentration range（0.25 mg/m L-1.5 mg/m L）,showing good biocompatibility.The cytotoxicity of blank vector HMZN and HMZN@MPN-La was investigated by MTT method.The results showed that the cell survival rate was above 80%when the concentration was below 400μg/m L.In vitro anti-tumor experiment results showed that DOX and drug loaded nanoparticle were within the concentration range of 0.625μg/m L-20μg/m L,and their inhibitory effects on tumor DOX@HMZN@MPN-La>DOX>DOX@HMZN.These results indicated that DOX@HMZN@MPN-La drug-loaded nanoparticles had more obvious killing effect on tumor cells than DOX.（4）Through fluorescence qualitative analysis of reactive oxygen species stimulated by nanocoliters,it can be seen that DOX@HMZN@MPN-La can produce ROS,which has the potential to kill cancer cells with adjuvant drugs.The uptake capacity of tumor cells to the nano-drug delivery system was evaluated by inverted fluorescence microscope.The drugs loaded by DOX@HMZN@MPN-La entered tumor cells more than those loaded by free DOX,DOX@HMZN and DOX@HMZN@MPN-La after lactose saturation.These results indicate that DOX@HMZN@MPN-La has a targeting effect on tumor cells,and drug-loaded nanoparticles can be more enriched in tumor cells,so it is expected to better inhibit tumor cells.（5）The determination of DOX in HepG2 hepatocellular carcinoma cells by HPLC was conducted to study the cellular pharmacokinetic.The doxorubicin uptake and elimination of HepG2 cells at different times were measured.The single-compartment model was used as the basis for pharmacokinetic analysis.Compared with free DOX,the elimination rate of DOX@HMZN was reduced to 79%,the half-life was extended to 1.27 times of free DOX,and the area under the curve was almost unchanged from free DOX;DOX@HMZN@MPN-La’s elimination rate was reduced to 49%of free DOX,its half-life was extended to 2.05 times that of free DOX,and the area under the drug curve was increased to 1.44 times that of free DOX,suggesting that the constructed nanodrug delivery system could effectively improve the intracellular retention time of drugs and prolong the half-life of drugs.It has a certain promoting effect on improving drug efficacy.