| Objective: on the basis of a reliable in vivo and in vitro analysis method, our study aims at preparation and evaluation of m PEG2000 modified long-circulating liposome which loading gambogenic acid, hydrogenated soybean lecithin, cholesterol and m PEG2000-PE. These nanocarriers were expected to improve the ability of water-soluble and irritation, extend the circulation time and so on. In addition, the reliability of using liposomes as antitumor drug carriers were investigated initially.Methods:(1) m PEG-PE was synthesized from m PEG 2000 by means of acyl chlorination and amidation(amino group in PE), and then was tested by infrared spectroscopy and nuclear magnetic resonance hydrogen spectrum.(2) m PEG-GNA-L was obtained through solvent evaporation method and solidification. We evaluated the pharmaceutical properties of m PEG-GNA-L using morphology, average particle size,enteapment efficiency(EE%), zeta postential,stability, hemolytic effect and so on.(3)the intravenous administration of GNA and m PEG-GNA-L to SD rats was investigated, and the main pharmacokinetic parameters were compared.(4) In vitro,the antitumor activity of GNA and m PEG-GNA-L were explored by a model of Hep G2 cells.Results:(1) m PEG-PE was successfully obtained by analyzing the characteristic absorption of FTIR and proton chemical shift from HNMR. Besides, the yield of m PEG-COCl and m PEG-PE were 71% and 73%, respectively.(2) The results revealed that the mean diameter, polydispersivity index(PI), zeta potential, and the entrapment efficiency of the liposomes were(121.1±1.07)nm,(0.192±0.01),(-43.3±0.42)m V and(83.74±1.136)%; The stability test showed that the particle size and appearance. maintained constant after storage at 4? and 25? for 60 d,meanwhile the encapsulation efficiency decreased slightly; The in vitro release kinetics demonstrated sustained release profile of m PEG-GNA-L and followed First-order kinetics unitarily; It had no hemolysis phenomenon during the hemolytic experiments when the total lipid concentration was 6.20 mg/m L.(3) Intravenous administration of m PEG-GNA-L demonstrated the t1/2? of GNA and m PEG-GNA-Lwere 1.583 min and 4.239 min, respectively. The t1/2? were 16.37 min and 67.897 min, respectively. Cmax of GNA and m PEG-GNA-L were 3.872 mg/L and 10.176mg/L, respectively. MRT0-? of GNA and m PEG-GNA-L were 12.67 min and 31.567 min, respectively. MRT0-? of GNA and m PEG-GNA-L were 14.16 min and 41.475 min, respectively. AUC0-? of GNA and m PEG-GNA-L were 49.965 mg/L·min and176.349mg/L·min, respectively. AUC0-? of GNA and m PEG-GNA-L were 67.442mg/L·min and 232.523mg/L·min, respectively.(4) MTT analysis confirmed that antitumor activity of GNA was slightly enhanced, and m PEG-L formulations showed the materials was non-toxic. IC50 of GNA and m PEG-GNA-L was 13.142 ?g/m L and10.758 ?g/m L, respectively.Conclusion: In summary, our study evidenced that m PEG-GNA-L has higher entrapment efficiency, smaller size,better stability and can release drug from m PEG-GNA-L slowly, which completely in line with Pharmacopoeia standards.What's more, compared with GNA solution, m PEG-GNA-L show better in vitro antitumor activity on Hep G2 cells and extended in vivo half-life. Therefore,m PEG-GNA-L is a promising carrier for anti-tumor drug delivery. |
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