聚乙二醇-b-聚己内酯/聚己内酯单分散电喷微球的制备与亲水性研究

Preparation and Hydrophilic Characterization of Monodispersed PEG-b-PCL/ PCL Microspheres by Electrospraying

用静电喷雾法制备单分散性良好、亲水性的聚乙二醇-b-聚己内酯/聚己内酯(PEG-b-PCL/PCL)电喷微球。将聚乙二醇-b-聚己内酯(PEG-b-PCL)、聚己内酯(PCL)与氯仿混合磁力搅拌3 h后,采用静电喷雾的方法,以双亲(PEG-b-PCL)含量、流速、电压为变量,研究微球形态大小、粒径分布的变化,并研究微球亲水性随双亲含量的变化程度及微球在水中的分散性。双亲含10%～20%、流速1 mL/h、电压10 kV时能得到成球性佳、粒径5～6μm的单分散性良好的微球,粒径的变异系数为15%～21%;双亲含量增至30%,微球之间由较多的纤维连接;双亲含量由0增至20%时,接触角由126.2°±4.8°降至29.9°±4.9°,差异具有统计学意义(P<0.05),通过改变双亲含量能有效改善微球的亲水性,同时,加入10%～20%双亲的微球在水中分散性佳,能形成均匀的混悬液。PEG-b-PCL/PCL能得到单分散、亲水性佳的微球,为进一步制备载药微球提供条件。

This study is aimed to prepare monodispersed and hydrophilic microspheres with Poly(ethylene glycol)-b-poly(ε-caprolactone)/Polycaprolactone(PEG-b-PCL/PCL) by electrospraying. PEG-b-PCL and PCL was dissolved in chloroform to prepare a mixture solution, which was magnetically stirred for 3 hours. The influence of the content of PEG-b-PCL, flow rate and the voltage of the electrospraying on the morphology, size, and size distribution of microspheres were investigated, The influence of PEG-b-PCL on hydrophilicity of microspheres and the dispersion of the microspheres in water was investigated. Monodispersed spherical microspheres with average particle sizes ranging from 5 to 6 μm and the coefficient of variation ranging from 15%~21% could be fabricated when the content of PEG-b-PCL was 10%~20%, flow rate was 1 mL/h, and voltage was 10 kV. Microspheres along with fibers could be fabricated when the content of PEG-b-PCL was 30%. The contact angle of the microspheres decreased from 126.2°±4.8° to 29.9°±4.9° when the content of PEG-b-PCL was increased from 0 to 20%, and the differences showed statistical significance(P<0.05), indicating that changing the content of PEG-b-PCL could improve the hydrophilicity of the microspheres. In the meantime, microspheres with 10%~20% of PEG-b-PCL could form homogeneous dispersions in water. Conclusion: Monodispersed microspheres with improved hydrophilicity could be fabricated with PEG-b-PCL/PCL, which would be a foundation for further research on hydrophilic drug-loaded microspheres.