Preliminary Study On Pharmacokinetics And Pharmacodynamical Relationship Of Peglated Gambogenic Acid Nanostructured Lipid Carriers

Objective: The targets of anti-tumor drugs are generally distributed within the cells,and the certain extent plasma drug concentrations don't fully represent efficacy of the drug.Therefore,the purpose of this study was to establish the intracellular Gambogenic acid(GNA)drug concentration assay method to study the changes in pharmacokinetics parameters and cellular uptake mechanism of PEGylated gambogenic acid nanostructured lipid carriers(P-GNA-NLC)and their anti-tumor effects in vitro,in order to explore the relationship between the pharmacodynamics and pharmacokinetics of P-GNA-NLC from the cellular level and to provide a theoretical basis for the evaluation of P-GNA-NLC,which provides the basis for the application of the new anti-tumor drug GNA to the clinic,and to provide a reference for the optimization of the new vector.Methods: In this study,cell line A549 was used as a cell model,the intracellular GNA content was determined by HPLC.Meanwhile,the pharmacokinetic parameters and uptake pathways of P-GNA-NLC and GNA in A549 cells were studied by HPLC.The MTT and flow patterns were also used to study the role of GNA and P-GNA-NLC against A549 tumor cells.Results:(1)A simple,convenient and efficient method for determination of intracellular GNA content was established in this paper.(2)The study of the pharmacokinetic parameters of GNA demonstrated that the GNA encapsulated by P-NLC can prolong the half-life of GNA in A549 cells and Retention time and reduce the clearance rate of GNA(3)MTT and apoptosis experiments can prove that P-GNA-NLC can well enhance the anti-tumor effect of GNA.(4)GNA and P-GNA-NLC could be obtained through active transport into A549 cells,and GNA was obtained by the caveolae-mediated endocytosis(Cav-ME)and maicropinocytosis into the cells.P-GNA-NLC could not only be internalized by Cav-ME and maicropinocytosis methods,but it can also be obtained by clathrin-dependent endocytosis(CDE),and the differences in pharmacodynamic and pharmacokinetic parameters of GNA and P-GNA-NLC may be related to the mode of transport.Conclusion: The relationship between P-GNA-NLC cell pharmacokinetics and drug efficacy was investigated from the cellular level.When the initial cell uptake of GNA was comparable to that of P-GNA-NLC at the same concentration,the pharmacodynamics results showed that GNA has weaker effect on A549 cells than P-GNA-NLC.The results of cellular pharmacokinetics showed that the pharmacokinetic parameters of P-GNA-NLC were significantly improved compared with GNA.The study of the uptake mechanisms of GNA and P-GNA-NLC by A549 cells revealed that there are common ways for GNA and P-GNA-NLC to enter cells,and there are different ways.GNA was obtained by the caveolae-mediated endocytosis(Cav-ME)and macropinocytosis into the cells,P-GNA-NLC could not only be internalized by Cav-ME and macropinocytosis methods but it can also be obtained by clathrin-dependent endocytosis(CDE),combined with pharmacokinetic parameters experiments,cell pharmacodynamic experiments and transport mechanisms.It finally concluded that P-GNA-NLC changes the distribution of GNA in A549 cells and intracellular processes by changing the transport pathway of GNA into cells,thereby improving GNA's effect of anti-A549 cells.This paper initially demonstrated that the drug efficacy of cells has a certain relationship with the form and route of drug entry into cells.This thesis provides a theoretical basis for the further development and application of gambogenic acid and its nano-lipid carrier for further optimization and development of new dosage forms,which will provide a reference for the clinical application of GNA.