两亲性聚乙二醇接枝聚乳酸胶束的制备及特性

Preparation and characterization of amphiphilic polyethyleneglycol-graft- poly(lactic acid)(PPLA) copolymer micelles

摘要:

本实验制备了低分子量聚乙二醇接枝聚乳酸（PPLA）共聚物胶束 ,并对其理化性质和体外释药特性进行了评价。通过静态水接触角法测定材料亲水性；溶剂挥发法制备PPLA胶束，并采用芘荧光探针技术、倒置成像显微镜、动态激光散射仪对PPLA临界胶束浓度（CMC）、胶束形态、粒径进行表征。单因素实验考察了投药量、丙酮用量、药物与材料加入顺序对包封率的影响。结果表明，PPLA的水接触角接近5?；CMC为3?0-4g?L-1；胶束呈球形，平均粒径小于200nm，Zeta电位≤-20Mv，室温、稀释、碱性条件下稳定；最佳制备条件为：0.8mg萘普生、10mgPPLA同时溶解于1ml丙酮中，再滴入10ml水中。载药胶束在37℃ PBS(0.01 mol?L-1)中可持续稳定释放五天。因此PPLA接枝共聚物可以作为疏水性药物的给药载体。

Abstract:

To prepare PPLA polymeric micelle and investigate their general properties, in vitro drug release characteristics. The surface hydrophilicity investigated by static water contact angle method. Using rotary evaporation method for reparation graft copolymer micelles. Critical micelle concentration(CMC), diameter, morphology and surface potential of the micelles were investigated by pyrene fluorescent probe technique,inverted imaging microscope and dynamic light scattering (DLS), respectively. Single factor tests and orthogonal tests on the the ratio of acetone, addition amount and addition sequence of material and drug were carried out for optimization. The in vitro release behavior of naproxen from polymeric micelles was investigated using dialysis method .The results indicated the water contact angle of the PPLA film was nearly 5? CMC was 3?0-4g?L-1. The micelle was globular-shaped ，had a narrow size distribution with an average particle size under of 200nm,the Zeta potential was lower than-20 mV, while dilution, standing and alkaline change to basic condition had no effect after preparation. The optimum preparation conditions were 0.8mg naproxen,10mgPPLA simultaneous dissolution in 1.0ml acetone，then drop into 10ml water. In PBS(0.01 mol?L-1)at 37℃ can duration release be up to 5 days. So we can concluded that PPLA would be a noveles applied Polymer Carriers as promising drug delivery system for hydrophobic drugs.