Preparation And Targeting Evaluation Of HA-Modified Apigenin PLGA Nanoparticles

Apigenin（API）,has anti-tumor,cardio-cerebral vascular protection,anti-virus,anti-bacterial and other functions.Apigenin has also been studied in vitro and in vivo in the treatment of colon cancer.Experiments have shown that apigenin can inhibit the proliferation and invasion of colon cancer cells SW480,SW620,and HCT-8.It can also inhibit the growth and metastasis of colorectal cancer by regulating transgelin protein^[1-5].Apigenin has great promise in the treatment of colon cancer,and its therapeutic effect has been confirmed.Therefore,using apigenin as a model drug,poly（lactic-co-glycolic acid）（PLGA）nanoparticles modified with hyaluronic acid（HA）,a target molecule of colon cancer,were prepared.In order to achieve the role of colon cancer targeting.In this project,a high performance liquid chromatography（HPLC）method was developed for the quantitative detection of apigenin,and a methodological investigation was conducted on the method.As a result,it was found that using this method to determine the content of apigenin was simple and highly sensitive.Precision and recovery meet requirements,good specificity and repeatability.Using apigenin as a model drug and PLGA as a carrier,PLGA Nanoparticles Loaded with Apigenin（PLGA-API-NPs）were prepared by an emulsifying solvent volatilization method,and then the surface of PLGA-API-NPs was subjected to chitosan（CS）modification to prepare CS Coated PLGA Nanoparticles Loaded with Apigenin（CS-PLGA-API-NPs）,and HA was connected to the outer layer by electrostatic adsorption to form HA Coated PLGA Nanoparticles Loaded with Apigenin（HA-PLGA-API-NPs）.With drug loading and particle size as the evaluation indicators,the main factors affecting the quality of HA-PLGA-API-NPs were screened by single factor analysis:the ratio of drug and carrier,the ratio of water phase and oil phase,ethanol and dichloride The proportion of methane.Taking the drug loading and particle size of HA-PLGA-API-NPs as the evaluation indicators,the prescription was optimized by response surface methodology.The optimal formulation of HA-PLGA-API-NPs was:Oil-water ratio is 1:6,ethanol-methylene chloride ratio is 5:7.5,drug loading ratio is1:10,emulsifier concentration is 4 mg/m L,chitosan concentration is 0.1 mg/m L,HA concentration is 0.25 mg/m L,prepared PLGA nanoparticles have good reproducibility.The physical and chemical properties of HA-PLGA-API-NPs were characterized by means of particle size potential analyzer,high performance liquid chromatography and other detection methods,including particle size and distribution,Zeta potential,in vitro release and stability.The average particle size of the PLGA-API-NPs sample prepared according to the best prescription is 210.3 nm,the polydispersity index（PDI）is 0.147,and the zeta potential is-26.3 m V;the average particle size of the CS-PLGA-API-NPs sample is The diameter was234.3 nm,the PDI was 0.173,and the zeta potential was+27.9 m V.The average particle size of the HA-PLGA-API-NPs sample was 247.2 nm,the PDI was 0.194,and the zeta potential was-32.7 m V.The change of particle size and the change of Zeta potential from negative potential to positive potential and then to negative potential indicate that HA-PLGA-API-NPs were successfully prepared.HA-PLGA-API-NPs have obvious sustained release ability in in vitro release studies.The preliminary stability results show that the prepared HA-PLGA-API-NPs have average stability,and it is recommended to store them directly in a refrigerator at 4℃if conditions permit.In this paper,HT-29 and HRT-18 colon cancer cells were selected as the high and low expression models of CD44 receptor,respectively.The cytotoxicity and difference of apigenin and different modified PLGA apigenin nanoparticles on the two cells were investigated.Effect of modification on the ability of two cells to take up nanoparticles.The results showed that the blank nanoparticles were less cytotoxic to the two cells.Compared with HRT-18,HA-PLGA-API-NPs was more cytotoxic to HT-29.Compared with other modified nanoparticles,HA-CS-PLGA-API-NPs is also more cytotoxic.Cell uptake experiments demonstrated this result.HT-29 cells had a higher uptake of HA-PLGA-Di O-NPs,demonstrating that HA-modified nanoparticles can effectively improve the targeting of CD44 receptors by nanoparticles,thereby Increase intake.In this subject,HT-29 and HRT-18 colon cancer cells were used to successfully establish a solid tumor model under the armpit of BALB/C nude mice.Different modified fluorescent dye-coated nanoparticle tail veins were injected into mice,and the animals were imaged using live animal imaging technology.By analyzing the degree of fluorescence accumulation in mice,PLGA-Di R-NPs and Targeting of HA-PLGA-Di R-NPs to two cells.The results showed that compared with PLGA-Di R-NPs,HA-PLGA-Di R-NPs has a stronger target for HT-29 solid tumors in the axilla of mice,and two kinds of nanoparticles targeted HRT-18 in the axilla of mice The difference in targeting of solid tumors is small,and the targeting is not obvious.This result further demonstrates that HA-PLGA-Di R-NPs prepared by this project is selective for colon cancer cells with high expression of CD44.