Preparation of lipid membrane-wrapped nanoparticles loaded with metformin polymer and doxorubicin and evaluation of their therapeutic effect on breast cancer / 药学学报

In this study, the lipid membrane-wrapped nanoparticles loaded with metformin polymer (PolyMet) and doxorubicin (DOX) was prepared and then evaluated therapeutic effect on breast cancer. An anionic chain PGA-DOX based on γ-polyglutamic acid (PGA) with DOX was synthesized via amidation reaction and characterized by 1H NMR. The PGA-DOX and PolyMet were loaded via electrostatic attraction to prepare the co-delivery nanoparticles system (PolyMet-DOX-NPs). Then, PolyMet-DOX-NPs were coated with cationic liposome membrane to form the core-membrane structural system (PolyMet-DOX-lipid-nanoparticles, PolyMet-DOX-LNPs). The structure and morphology of PolyMet-DOX-LNPs were observed by transmission electron microscope. The particle size, zeta potential, encapsulation efficiency (EE), drug loading (DL), release behavior in vitro of PolyMet-DOX-LNPs were investigated. The MTT assay was used to examine the cytotoxicity of PolyMet combined with DOX on 4T-1 cells. The 4T1Fluc tumor-bearing mice model was used to evaluate the therapeutic efficacy of PolyMet-DOX-LNPs in vivo. All animal experiments were performed in line with ethical standards and approved by the Animal Experiments Ethical Committee of Zhejiang Chinese Medical University. 1H NMR spectrum showed that PGA-DOX was successfully synthesized with DOX grafting rate of (72.03 ± 1.29) %. The EE and DL of PolyMet-DOX-LNPs was (72.76 ± 1.92) % and (1.16 ± 0.12) %, respectively. PolyMet-DOX-LNPs exhibited a suitable size of (159.3 ± 7.4) nm and positive charge of (+36.3 ± 1.9) mV with good spheroidal morphology and dispersibility. The release profiles in vitro showed that PolyMet-DOX-LNPs exhibited a slowly and maintained release behavior at physiological pH value (pH 7.4) within 48 h. Further studies showed that PolyMet combined with DOX could synergistically enhance the cytotoxicity on 4T-1 cells. Bioluminescence imaging (BLI) result showed that the luminescence signal intensity of 4T-1Fluc cells was reduced after treatment with PolyMet-DOX-LNPs and the tumor volume growth was also inhibited. Additionally, the H&E staining and changes of body weight showed that PolyMet could reduce the toxicity of DOX. To sum up, PolyMet has a good synergistic effect with DOX in the treatment of breast cancer, which provide the foundation for this novel metformin polymer on the anti-tumor application.

Effects of Elemene Injection on the kinetics of intracellular transport of Gefitinib in PC-9/GR cells / 中成药

AIM To study the effects of Elemene Injection (ELE) on the kinetics of intracellular transport of Gefitinib (GEF) in PC-9/GR cells and to probe the role of ELE in reversing oncological multidrug resistance.METHODS The intracellular pharmacokinetic behavior of D-luciferin potassium salt,a substrate of an ATP-binding cassette (ABC) protein,was investigated in PC-9/GRFluc cells using real-time bioluminescence imaging.The resistance of PC-9/GR cells to GEF was determined by MTT assay.Compusyn software was used to analyze the synergistic effect of GEF and ELE,and HPLC to detect the uptake of GEF in PC-9/GR cells.RESULTS The respective GEF IC50 values of 0.01 μg/mL in PC-9 cells and 1.50 μg/mL in PC-9/GR cells revealed the 150 times drug resistance of PC-9/GR to PC-9 cells.The significantly enhanced intracellular fluorescence intensity of D-fluorescein potassium salt by the intervention of ELE also indicated remarkable GEF uptake increase in PC-9/GR cell line (P ＜ 0.05) due to the synergistic result.CONCLUSION Partly as the mechanism in reversing oncological multidrug resistance,ELE,a booster for the fluorescence intensity of D-luciferin potassium salt,promotes cellular uptake of GEF by inhibiting efflux function of ABC proteins.

Impact of Coix seed oil on fluorescence excretion pharmacokinetics and protein expression in doxorubicin-resistant cells MCF-7/DOX / 药学学报

This study was designed to explore the mechanism of Coix seed oil (Coix) impact on the drug resistance, bioluminescence imaging (BLI) and the efflux of D-luciferin potassium salt, the substrate of ABC transporters, in doxorubicin-resistant breast cancer cells. Multidrug resistance (MDR) gene and protein expression were analyzed in the cells by q-PCR and Western blot. First, in order to investigate the effect of the efflux function by ABC protein, a cell line with overexpressed luciferase was established in MCF-7 cell line. BLI was used to monitor the efflux kinetics of D-luciferin potassium salt before and after Coix treament. The results showed that the efflux of D-fluorescein potassium from MCF-7/DOXFluc was lessened when pretreated with Coix, which means that Coix may decrease the efflux of other chemotherapies using ABC transporters. Both of the results of q-PCR and Western blot showed that gene and protein expression of ABC transporters such as ABCG2, ABCC1 and ABCB1 were down-regulated by Coix treatment. The efficacy of Coix reversing MDR was verified with the chemotherapy medication doxorubicin (DOX). MTT assay showed that Coix increased the inhibitory effect of DOX on proliferation of MCF-7/DOX, and the optimal combination of ratio was 25 times that of DOX. The results suggest that Coix may reverse MDR of the substrate of ABC transporters from two aspects, one is to cut down the ABC protein efflux function, and the other is to decrease the quantity of ABC gene and protein expression.

Study on blood-brain distribution of lactones in rats after oral administration of Ginkgo biloba extract by blood-brain synchronization microdialysis / 中草药

Objective: To study the blood and brain drug concentration and drug distribution coefficient of lactones in rats after oral administration of Ginkgo biloba extract (GBE). Methods: Blood-brain synchronization microdialysis was used in combination with HPLC-MS/MS inthis study. Probes were buried into rat brain and jugular vein to collect the blood and brain micro dialysis liquid in rats after oral GBE in different periods. The lactones in the dialysate were analyzed by HPLC-MS/MS, and the blood and brain drug concentration was depicted according to the results. Then the drug distribution coefficients of each component in blood and brain (AUCbrain/AUCblood) were calculated. Results: After GBE suspension (600 mg/kg) oral gavaging in the rats, the blood samples and brain samples were obtained and detected by HPLC/MS/MS. Ginkgolides A, B, and C were detected in both blood and in brain, but bilobalide could be detected just in blood. The drug distribution coefficients in the blood and brain (AUCbrain/AUCblood) were as follows: Ginkgolide A was 2.911%, ginkgolide B was 3.126%, and ginkgolide C was 0.337%. Conclusion: Simultaneous multiple microdialysis technique can be used to detect multiple components in different tissues simultaneously. It also has other characteristics, such as continuous sampling on living animals with small sample volume and little tissue damage, which can save animals. In all, simultaneous multiple microdialysis could be a good method for exploring the effect components in Chinese medicine and their distribution at effect sides.