Preparation Of Trastuzumab Modified Nanocarrier Loaded With Docetaxel And Its Preliminary Study In The Treatment Of Breast Cancer

Docetaxel(DTX)is a chemotherapeutic drug,which that can play a therapeutic role by inhibiting the depolymerization of microtubules and blocking the cell cycle.At present,it is often used in clinical treatment of metastatic breast cancer.Breast cancer is a cancer that has a serious impact on women’s health today.DTX,as a chemotherapy drug for breast cancer,has poor water solubility.When it is used,it needs to add the solubilizer Tween 80.However,this solubilizer will cause serious allergic reactions and other adverse reactions,which will cause great damage to normal cells of the body.Therefore,it is essential to prepare a nanocarrier to selectively transport DTX to the lesion site to reduce the side effects and adverse reactions when DTX is used.In this study,a DTX loaded lipid polymer nanoparticle was firstly prepared.The components of the nanoparticles were poly(D,L-lactide-co-glycolide)(PLGA),polyethylenimine(PEI)and and lipids(egg PC).PEI is a kind of cationic nanoparticle material.Its high positive charge property can make it attract electronegative substances,such as nucleic acid,polysaccharide,protein and so on.Trastuzumab(Tmab)is a recombinant humanized monoclonal antibody,which can specifically recognize human epidermal growth factor receptor 2(HER2).Therefore,Tmab was adsorbed on the surface of lipid polymer nanoparticles by electrostatic adsorption,which can reduce the damage to antibody as much as possible in this gentle way.At the same time,the specific recognition ability of Tmab to HER2 positive breast tumor cells was used to enhance the targeting of nanocarriers.The specific contents are as follows:1.Establishment of in vitro analytical method for DTX and study on Tmab stabilityIn this part,high performance liquid chromatography(HPLC)was used to detect the drug loading of nanoparticles and the concentration of DTX in vitro release fluid.The specificity,accuracy and precision of this method were all good.The concentration of Tmab was detected by BCA protein concentration detection method and in the detection range of 5.0-800.0 μg/m L,the linear relationship was good.The secondary and tertiary structures of Tmab in the electrostatic incubation solution were investigated by circular dichroism and fluorescence spectrometry respectively.The results showed that the secondary and tertiary structures of Tmab were not greatly affected by the electrostatic incubation solution.2.Preparation and formulation selection of the Tmab adsorbed lipid polymer nanoparticles(e Tmab-PPLNs)In this part,lipid polymer nanoparticles were prepared by O/W emulsion solvent volatilization method and Tmab was connected by electrostatic adsorption.The results showed that the average particle size of optimized e Tmab-PPLNs was 217.4±13.36 nm,polydispersity index(PDI)was 0.116±0.057,potential was 0.056±0.315 m V,encapsulation efficiency was about 31%,and the repeatability of the optimal formulation was good.3.Evaluation of physical and chemical properties of e Tmab-PPLNsIn this part,the obtained e Tmab-PPLNs were characterized.The results of transmission electron microscopy showed that the surface of the nanoparticles was smooth and round without adhesion.In the in vitro stability experiment,e Tmab-PPLNs showed good stability under different environments.In the hemolysis experiment in vitro,the hemolysis rate of e Tmab-PPLNs was less than 2%,which proved that the nanoparticles had good biocompatibility.Two kinds of breast tumor cells BT474 and MCF7 were selected to study the cell killing and cell uptake of nanoparticles in vitro.In vitro cytotoxicity test,compared with PPLNs without Tmab,e Tmab-PPLNs had a higher killing power on breast cancer HER2 positive cell BT474,and the killing power of e Tmab-PPLNs on breast cancer HER2 positive cell BT474 was also higher than that on breast cancer HER2 negative cell MCF7.Similarly,in the cell uptake test in vitro,the uptake of e Tmab-PPLNs by breast cancer HER2 positive cell BT474 was stronger than that by breast cancer HER2 negative cell MCF7,and the uptake of e Tmab-PPLNs by BT474 was stronger than that of PPLNs.These results showed that e Tmab-PPLNs could effectively transport DTX to HER2 overexpressed breast cancer cells through the action of Tmab.In conclusion,the DTX-targeted nanocarriers prepared in this paper can change the traditional way of DTX intravenous injection,avoid the adverse reactions caused by the use of solubilizer,improve the bioavailability of DTX,and reduce the damage to normal cells of the body.It is a promising DTX targeted delivery system for the treatment of breast cancer.