Department of Organic and Polymer Materials Chemistry, Faculty of Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan.
Colloids Surf B Biointerfaces. 2011 Oct 15;87(2):433-8. doi: 10.1016/j.colsurfb.2011.06.004. Epub 2011 Jun 12.
We developed a novel "spray dry-based" method for preparing surface-modified particle via "block copolymer-assisted" emulsification/evaporation for pulmonary drug delivery. The method included three steps: (1) o/w emulsion containing both hydrophobic polymers and amphiphilic block copolymers was obtained by emulsification of water and a polymer-containing organic solvent, (2) the o/w emulsion was misted with a nebulizer, and (3) the emulsion mists were dried by a heater. In this way, the hydrophobic polymers and the hydrophobic part of the amphiphilic block copolymers gradually tangled during the evaporation of organic solvents from the o/w emulsion. Consequently, the hydrophilic polymer chain was introduced on the particle surface. The particle surface can be easily modified although there are no reactive groups in the hydrophobic polymer molecules. We successfully obtained dry PEG-PLA/PLGA microparticles by controlling the weight ratio of the block copolymer and the hydrophobic polymer. The introduction of PEG to the particle surface involves an increase in the Zeta potential of the particles. Interestingly, the "dimpled" microparticles having a diameter of approximately 2 μm were obtained. The "dimpled" microparticles can serve as drug carriers for pulmonary drug delivery, because the particles have a large surface area. We expect that this novel surface-modification technique will enable efficient fabrication of particles in drug delivery systems.
我们开发了一种新颖的“喷雾干燥基”方法，通过“嵌段共聚物辅助”乳化/蒸发来制备用于肺部给药的表面改性颗粒。该方法包括三个步骤：（1）通过水和含聚合物的有机溶剂的乳化获得包含疏水性聚合物和两亲性嵌段共聚物的 o/w 乳液，（2）用喷雾器将 o/w 乳液雾化，（3）用加热器干燥乳液雾。通过这种方式，疏水性聚合物和亲水性嵌段共聚物的疏水性部分逐渐在 o/w 乳液中的有机溶剂蒸发过程中缠结。因此，亲水性聚合物链被引入颗粒表面。尽管疏水性聚合物分子中没有反应性基团，但可以很容易地对颗粒表面进行改性。通过控制嵌段共聚物和疏水性聚合物的重量比，我们成功地获得了干燥的 PEG-PLA/PLGA 微球。PEG 引入颗粒表面会增加颗粒的 Zeta 电位。有趣的是，我们获得了直径约为 2 μm 的“凹坑”微球。这些“凹坑”微球可以用作肺部给药的药物载体，因为它们具有较大的表面积。我们期望这种新颖的表面改性技术将能够有效地制备药物输送系统中的颗粒。
