Preparation And Activity Evaluation In Vitro Of10-Hydroxycamptothecin (HCPT)-loaded Glycyrrhizic Acid (GL)-conjugated Bovine Serum Albumin (BSA)Nanoparticles For Hepatocellular Carcinoma-targeted Drug Delivery

Hydroxycamptothecin as analogue of camptothecin, has a obviously effect for the treatment of liver cancer, but its anticancer activity is30times that of camptothecin. The characteristics contain poor solubility in water, short half-life, and instability that limit its clinical application. The method that wrapped with carrier material with nanotechniques can effectively increase the water dispersibility, stability, and long residual action of drug. Bovine serum albumin as a kind of biomacromolecule has better biocompatibility and biodegradability than synthesis and semi synthetic materials. The study showed that albumin can effectively prevent the lactone ring opening and maintain the stability of hydroxycamptothecin. The carrier coupled with the ligand is active targeting.there is glycyrrhizic acid receptor on the Liver cell surface, and the receptor was largely expressed on liver cancer cell surface, glycyrrhizic acid-modified carrier materials include liposomes, albumin nanoparticles have shown a liver targeting. The detoxification of liver increase the difficulty of normal drug treatment to liver cancer, and it is difficult for drug to reach lesions, and easy to cause side effects on normal tissue.In this research, we study a new type of liver cancer targeted drug delivery system containing hydroxycamptothecin. The preparation of glycyrrhizic acid coupled with bovine serum albumin loading hydroxycamptothecin was completed by using high-pressure emulsification method, and the product is liver cancer-targeting. Particle size plays an important role in screening optimal conditions of nanoparticles preparation. In the experimental design, the influencing factors containing concentration of BSA, volume ratio of water and the organic phase, homogenates time and homogenate speed, homogenization pressure and times. Characteristics of HCPT-loaded GL-conjugated BSA nanoparticles (GL-BSA-HCPT-NPs) such as the drug encapsulation efficiency and drug loading efficiency were studied. In addition, the solid state, the local toxicity, cell uptake, and the inhibitory rate to liver cancer of nanoparticles were also discussed. The research results are as follows:1. GL was coupled to bovine serum albumin (BSA) according to the references, the content of GL coupling on BSA is98.26μg/mg. Both characteristic peaks of GL and BSA can be found on the FTIR spectrum of BSA coupled with GL, and the peak of amido bond is stronger, it illustrates that GL is coupled with BSA successfully.2. The optimal conditions selected by single-factor method:BSA concentration was1mg/mL, the proportion of water and organic phase was25:1, the homogenate speed was5000rpm for1min, and the homogeneous pressure was800bar,7times. The sample prepared under optimal conditions, the average particle size is157.5nm and zeta potential is-22.51±0.78mV, drug encapsulation efficiency and drug loading efficiency was93.7%and10.9%. The particle size was found to be always<200nm and zeta potential was in the range of-20.34±4.60mV to-36.83±2.25mV without precipitation and stratified phenomenon. The GL-BSA-HCPT-NPs were nearly spherical and dispersed evenly, rather than stuck together. HCPT presented amorphously wrapped in GL-BSA, drug release in the vitro indicates that the drug delivery system can release continuously and slowly.3. The hemolysis test has shown the safety of GL-BSA as a novel drug delivery system, the new carrier will not lead the erythrocyte rupture and agglutination. The targeting properties of GL-BSA-HCPT-NPs in vitro containing cell uptake study and cell proliferation assay were studied. Cells incubated by GL-BSA-HCPT-NPs labeling FITC show more extensive fluorescence spots and stronger fluorescence intensity than samples without GL conjugated. MTT method was used to determine the inhibitory rate of samples, the inhibitory rate of GL-BSA-HCPT-NPs develops with raise of concentration, and it shows higher inhibitory rate under the same concentration and lower IC50value than other samples. The IC50values of GL-BSA-HCPT-NPs, BSA-HCPT-NPs, and HCPT sodium are0.78±0.015μg/mL,1.62±0.039μg/mL, and7.93±0.255μg/mL.All the results above show that GL-BSA-HCPT has good application values for hepatocellular carcinoma targeting therapy and provide a new prospect in hepatocellular carcinoma therapy.