Size effects of discoidal PLGA nanoconstructs in Pickering emulsion stabilization
Size effects of discoidal PLGA nanoconstructs in Pickering emulsion stabilization
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DOI：
10.1002/pol.20210748
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发表时间：
2022-01-20
影响因子：
3.4
通讯作者：
Palange, Anna Lisa
中科院分区：
文献类型：
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作者：
Cook, Alexander B.;Schlich, Michele;Palange, Anna Lisa
固体颗粒稳定的乳液，使用独特的形状定义的颗粒，由于配方简单和有趣的物理化学特性而受到越来越多的研究兴趣。然而，有必要系统地研究各向异性盘状微粒在乳液稳定中的作用，这些微粒是通过自上而下的制造方法实现的。本文研究了聚(d，L-丙交酯-乙交酯)盘状聚合物纳米结构尺寸对水包油乳液形成和稳定性的影响。采用光刻模板技术制备了直径分别为1、2和5微米的颗粒，并将其用于稳定中链甘油三酯(MCT)油乳剂。从1微米到5微米的DPN稳定乳液的三相接触角从85度+/-7度下降到68度+/-12度，显示出粒子的“亲水性”随着尺寸的增加而增加。显微成像显示，液滴的平均直径和分散性随着颗粒大小的增加而增大，并且在油-水界面上存在DPN。在1和2微米DPN的情况下，DPN乳剂的稳定性约为24小时或更短。在5微米DPN的情况下，乳状液的稳定性小于12h。最后，DPN脱离自由能增量G(Dw)和超额表面覆盖度C的计算表明，尽管盘状DPN具有很高的粘附能，但对于大于2微米的DPN，乳状液的稳定性主要受重力的影响。本研究中PLGA和MCT油的使用对未来Pickering乳液在药物和药物输送应用中的使用具有重要意义。
Solid particle stabilized emulsions, using unique shape defined particles, are receiving increasing research interest due to ease of formulation and interesting physiochemical characteristics. There is, however, a need to systematically investigate the effect of anisotropic discoidal microparticles, realized with top-down fabrication approaches, in emulsion stabilization. Here, the effect of poly(d,l-lactide-co-glycolide) (PLGA) discoidal polymeric nanoconstruct (DPN) size on the formation and stability of oil-in-water emulsions is studied. Particles with a diameter of 1, 2, and 5 mu m are fabricated with a lithographic templating technique, and used to stabilize medium chain triglyceride (MCT) oil emulsions. Three phase contact angles decreased from 85 degrees +/- 7 degrees to 68 degrees +/- 12 degrees moving from 1 to 5 mu m DPN stabilized emulsions, showing a particle "hydrophilicity" increase with size. Microscopy imaging showed that the mean droplet diameter and dispersity increased with particle size, and that DPNs were present at the oil-water interface. DPN based emulsions were stable for about 24 h or less in the case of 1 and 2 mu m DPNs. Emulsion stability was shorter than 12 h in case of 5 mu m DPNs. Finally, calculations of DPN detachment free energies Delta G(dw) and excess surface coverages C-excess demonstrated that, despite the significantly high adhesion energy of the discoidal DPN, emulsion stability was mostly affected by gravitational forces for DPN sizes above 2 mu m. The use of PLGA and MCT oil in this study is relevant for future use of Pickering emulsions in pharmaceutical and drug delivery applications.