The Study Of Folic Acid Modified Nanostructured Lipid Carrier Loaded With Gambogenic Acid

Breast cancer has become an important public health problem in the current society.Its incidence rate ranks first among female malignant tumors and is one of the common tumors that threaten women's physical and mental health.At present,the main methods for clinical treatment of breast cancer include surgical resection,radiotherapy,and chemotherapy.However,regardless of chemotherapy or radiotherapy,they have low tumor targeting,and they are also harmful to normal tissues while destroying cancer cells.As a broad-spectrum anticancer drug,gambogenic acid can effectively inhibit the proliferation of breast cancer cells.The folate receptor is highly specific on the surface of cancer cells and can be used as a binding target for antitumor drugs.In order to improve its active targeting,enhance anti-tumor acti vity,and reduce toxic and side effects,a folic acid modified nanostructured lipid carrier loaded with gambogenic acid(FA-GNA-NLC)was constructed,and the formulation was physicochemically characterized and evaluated in vitro and in vivo.The specific research contents are as follows: 1.Preparation of a gambogenic acid nanostructured lipid carrier and methodology for determination of its encapsulation efficiency.In this chapter,nano-materials were used as carrier,and gambogenic acid was used as a model drug.The gambogenic acid nanostructured lipid carrier(GNA-NLC)was prepared by emulsification evaporation-low temperature curing method.Meanwhile,PEG was used as a bridge to construct a folic acid(FA)modified nanostructured lipid carrier loaded with gambogenic acid(FA-GNA-NLC).The obtained nanoparticles had average particle size of(16.47± 0.69)nm,zeta potential of(-4.66±8.97)m V,PDI(0.15±13.12).The encapsulation efficiency of gambogenic acid was 99%;at the same time established a method for determining the encapsulation efficiency of GNA-NLC,which had a good linear relationship in the linear range,the method repeatability was in accordance with the regulations,and the prepared sample was stable within 24 h.2.Physicochemical characterization of a folic acid modified nanostructured lipid carrier loaded with gambogenic acid.In order to better store the nanostructured lipid carrier,5% glucose was selected as the lyoprotectant of the GNA-NLC preparation.After reconstitution,the particle size was small and uniform.Under the transmission electron micrograph,the preparations were all spherical,with good dispersion,round shape and uniform size distribution.DSC and X-ray results indicated that the GNA was encapsulated in the formulation in molecular form rather than in crystalline form.The hemolytic test indicated that the preparation had good biocompatibility and blood safety.3.Study on tumor cell uptake of FA-GNA-NLC.In the experiment of this chapter,coumarin-6 was used as a fluorescent probe to prepare coumarin-6-NLC.The fluorescence intensity of MDA-MB-231 cells and 4T1 cells in three groups of nanoparticles was observed by a high content imaging system.The fluorescence intensity indicates that the nanoparticles can be efficiently taken up by the cells,and the GNA is mainly distributed in the nucleus.After being modified by FA,the nanoparticles can enter the cell and increase the accumulation of GNA in the cells through the specific binding of FA to the FA receptor,which enhances the uptake of Cou-6 by the cells.4.In vitro anti-tumor effect of FA-GNA-NLC.This experiment,mouse breast cancer 4T1 cells were used as an in vitro tumor model,and the cytotoxicity of different preparations was detected by CCK-8 method.Cytotoxicity results showed that after the surface of GNA-NLC was modified by folic acid,folic acid specifically binds to the folate receptor(FR)on cancer cells,and the targeting effect of drug cancer cells is enhanced.Thereby,the anti-tumor activity of GNA in vitro is improved.5.In vivo biodistribution of FA-GNA-NLC and antitumor pharmacodynamics study.In this chapter,a model of mouse breast cancer 4T1 cell-bearing nude mice was constructed.Di R is used as a fluorescent molecular probe.The biodistribution of Di R-Sol,Di R-NLC and FA-Di R-NLC in tumor-bearing nude mice was investigated by In vivo image system(IVIS)small animal in vivo imaging system.In order to investigate the anti-tumor effect of the comparative preparations before and after folic acid modification,the anti-tumor effects of GNA-Sol,GNA-NLC and FA-GNA-NLC in tumor-bearing nude mice were compared by intravenous injection of drugs.At the same time,the main organs such as heart,liver,spleen,lung and kidney of nude mice were taken for histopathological study by HE staining to evaluate the safety of the main organs.