可生物降解聚乳酸纳米粒的制备及表征

Preparation and Characteriztion of Biodegradable Poly(lactic acid) Nanoparticles

采用乳化 -溶剂蒸发法 ( O/W)制备聚乳酸 ( PLA)纳米粒 ,用透射电子显微镜和激光粒度仪对纳米粒进行了表征 ,纳米粒具有规整的球形且正态分布 ,同时从有机相和水相的体积比、聚合物的浓度、表面活性剂的选择及表面活性剂的浓度等几个因素对纳米粒粒径大小的影响作了较详细地讨论。有机相与水相的体积比从 1∶ 3减小到 1∶ 30 ,纳米粒的粒径从 ( 30 6.2 + 1 1 ) nm减小到( 1 87.1 + 2 .4) nm;聚合物在有机相的浓度从 1 %(质量分数 )增加到 5 %(质量分数 ) ,纳米粒的粒径从 1 94nm增加到 32 1 nm;随着水相中表面活性剂浓度从 0 .5 (质量体积分数 )增大到 3.5 %(质量体积分数 ) ,纳米粒粒径从 2 0 2 nm减小 1 78nm且有一个低的多分散指数。

Poly(lactic acid) nanoparticles were prepared using the emulsion solvent evaporation technique (O/W). The morphological examination of nanoparticles was performed by means of a transmission electron microscope (TEM), and the mean particle size and size distribution were measured by laser light scattering technique. The effect of the volume ratio of the organic and aqueous phase, the polymer concentrations, the selection and concentration of surfactant on the nanoparticle sizes were investigated. The nanoparticle size was reduced from ( 306.2 +11) nm to ( 187.1 + 2.4 ) nm as the volume ratio of the organic and aqueous phase decreased from 1∶3 to 1∶30, increased from 194 nm to 321 nm as the polymer concentration in the organic phase increesed from 1% (% m/m ) to 5%(% m/m ), and reduced from 202 nm to 178 nm with low polydispersity as the concentration of surfactant increased from 0.5 (% m/v ) to 3.5% (% m/v ). The morphology of the nanoparticles was compared with that of the products from stirrer solvent evaporation and vacuum rotative evaporation methods.