| Etoposide(ETO),a semisynthetic epipodophyllotoxin derivative,is commonly used in the treatment of small cell cancer,lymphomas,and leukemia, especially for early diffusion and post-cure small cell cancer. It is the most active monomer in the treatment of small cell carcinoma and testicular cancer. However, etoposide has poor water solubility, low dosage oral bioavailability, relatively large individual differences and other shortcomings which have limited its widespread use, and the injections are usually added a large amount of surfactant solubilization, resulting in irritation and poor patient compliance. The above drawbacks to some extent restricted the widespread clinical application of etoposide. Therefore, in order to overcome these problems, this paper used the carrier, poly cyanoacrylate alkyl esters as a shell to simulate the structural characteristics of lipoprotein, and etoposide as the model drug to construct the etoposide loaded nanoparticles delivery system. The EPR effect and active targeting of bovine serum albumin(BSA) will make etoposide concentrate at the tumour site. The release of etoposide by existing nanoparticle delivery improved the drug availability at the liver site while reducing harmful side effects. This study will focus on Etoposide nanoparticles preparation, drug loading, targeting, and pharmacodynamics studies; however the full text is divided into the following five parts: Part Ⅰ ReviewIn this section, we review(1) the progress of liver and liver tumour targeting and(2) the application of polycyanoacrylate alkyl esters nanoparticles in drug delivery systems. These two review areas corresponded to the research content of this study and provided a theoretical basis for subsequent test work. Part Ⅱ The preformulation studyA HPLC analysis method for the drug content of ETO was established in this part. The experimental results showed that the ETO in vitro analysis method was accurate and the test method was feasible. PartⅢ The preparation and optimization of the nanoparticlesIn this chapter, ETO-PBCA NPs was prepared, then it was used as kernel, BSA modified with hyaluronic acid and ethylenediamine were used as the hydrophilic shell to prepare ETO-PBCA-BSAmodified NPs. Single factor and orthogonal experimental design was employed to optimize the prescription: The amount of α-BCA was 50μL, the ratio of dichloromethane and methanol solvent was 1:8(V:V); the ratio of phospholipids, hydrated sodium cholate and PVP was 4:3:3(W:W:W). The best validation results showed that: the encapsulation rate was(78.44 ± 3.93)%, the zeta potential was(-35.22 ±5.21)mV, average particle diameter was(12.057±2.43)nm, the protein carrier attached rate was(90.3±2.16)%. Every indicators of the five batches of ETO-PBCA NPs samples under the optimum preparing conditions was in line with the requirements, the optimized prescription reproducibility was also good and the encapsulation rate was stable. PartⅣ Physical and chemical properties and in vitro and in vivo studiesIn this chapter, the physical and chemical properties, in vitro release and pharmacokinetics in rats of nanoparticles were studied. TEM showed that the sizes of ETO-PBCA NPs and ETO-PBCA-BSAmodified NPs were relatively uniform and and the surface was smooth. DSC showed that ETO was present in the nano carrier with amorphous form. FTIR analysis showed that the hydrogen bonding between ETO and the PBCA carrier. In vitro release test showed that the PBCA nanoparticles as drug carrier had sustained release effect on the drug, and the BSA coated on the surface of the nanoparticles can also enhance this effect. Meanwhile, preliminary stability of ETO-PBCA-BSAmodified NPs powder after freeze drying was investigated. The result showed that the powders had good stability under the condition of 2~8℃ for 3months. Pharmacokinetics showed that ETO drug metabolism in rats was rapidly. After intravenous administration of 2h, the drug could be hardly detected in the plasma, and compared with the formulation group, the blood drug concentration was lower correspondingly at each time point. The MRT of ETO-PBCA NPs and ETO-PBCA-BSAmodified NPs were respectively 2.85 times and 6.35 times to free ETO. Compared with the free drug, ETO, the t1/2 of two nanoparticles preparation groups were extended to(1.07±0.177)h and(2.712±2.046)h and Auc0-t were respectively times 2.22 and 4.96 times to free ETO group; the FR were respectively 221.82% and 496.19% of free ETO. In a nutshell, the two kinds of nano preparations, ETO-PBCA NPs and ETO-PBCA-BSAmodified NPs exhibited sustained-release effect with ETO-PBCA-BSAmodified NPs as the best. PartⅤ Tissue distribution in mice, targeting and anti tumor effectIn this section, CIR mice were taken as animal model to investigate the tissue distribution, targeting and antitumor effect of nanoparticles. With free etoposide solution as the reference preparation, The preparation of the two groups, ETO-PBCA NPs and ETO-PBCA-BSAmodified NPs, were studied as the test preparation. The content of ETO in heart and kindy in the two nanoparticle groups kept under 2.5μg/g that was far below it in the free ETO group.1h after tail vein, the drug concentration in the tumor in the free ETO group was lower than the detection line, while the content of ETO in the two nanopartilce groups were still high, the concentration in ETO-PBCA-BSAmodified NPs were reached at 3.2μg/g, and after 3h the concentration was 1.92μg/g. The results showed that preparation with PBCA-BSAmodified as drug carrier has good tumor targeting effect, and can effectively accumulate in the tumor site, make better use of the drug effect.The results of targeted evaluation of nanoparticles were consistent with the results of tissue distribution in mice. The results also showed that PBCA- BSAmodified as the carrier of the drug loaded had good tumor targeting, also could reduce the side effects of drugs.Antitumor efficacy studies showed that, the three grous of free ETO, ETO-PBCA NPs and ETO-PBCA-BSAmodified NPs had different degrees of anti tumor effect. In the same dosage, the tumor in mice growed slower in the groups of ETO-PBCA NPs, ETO-PBCA-BSAmodified NPs, compared with free ETO, and was lowest in the ETO-PBCA-BSAmodified NPs group. Tumor inhibition rate showed that the inhibition rate of free ETO group was 38.29%, while the inhibition rate of the preparation groups was 46.33% and 61.59%. All mice were killed in 26 days after administration of intravenous injection of normal saline. In contrast, 42%, 60%, 75% of mice survived after injected the free ETO, ETO-PBCA NPs and ETO-PBCA-BSAmodified NPs respectively, the survival time was extended for another 3days, 9 days and 13 days. |
PDF Full Text Request