EAGER: Exploring the role of polymer thermodynamics in the formation of patches on polymer-core-shell particles

1348112 PI：道德EAGER奖支持一项研究计划，探索聚合物热力学在聚合物核心上形成补丁的作用。PI最近发现形成了一类新的片状颗粒，其具有独特的核-壳结构，由中空疏水性聚合物核和片状表面组成，片状表面由独立分布和定向在核表面上的基于单或双脂质聚合物的贴片制成。贴片形成的机制尚未了解。在聚合物芯上形成补丁是一种有些出乎意料的现象，因为在中性pH下具有正电荷的胺基团预期彼此排斥而不是形成簇或补丁。据推测，实验观察到的补丁形成现象是由于聚合物相分离现象。确定形成过程中所涉及的驱动力对于深入了解该过程是必要的。本探索性研究旨在研究：1）热力学相互作用（如聚合物-溶剂和聚合物-溶剂）在相分离现象中的作用和2）界面张力在相分离现象中的作用。在基本层面上，该建议将通过为相分离现象增加新的知识来推进自组装领域。在过去，相分离现象已被观察到，报告和讨论的系统，如二元自组装单分子膜（SAM）的正烷基硫醇的金，表面活性剂涂覆的纳米粒子和表面活性剂涂覆的基板，但不是在聚合物颗粒的表面。PI是第一个报告相分离现象也发生在两个不同的脂质聚乙二醇化官能团的存在下。对这一现象的充分理解对于片状颗粒与生物实体（如蛋白质、细胞和组织）之间的相互作用至关重要。这些片状颗粒在药物和疫苗递送中具有潜在的应用。

1348112PI: MoralesThis EAGER award supports a research plan for exploring the role of polymer thermodynamics in the formation of patches on polymeric cores. The PI has recently discovered the formation of a new class of patchy particles with a unique core-shell structure consisting of a hollow hydrophobic polymeric core and a patchy surface made of single or dual lipid-polymer based patches independently distributed and oriented on the surface of the core. The mechanism of patch formation is not yet understood. The formation of patches on polymeric cores was a somewhat unexpected phenomenon in light of the fact that amine groups, having a positive charge at neutral pH, were expected to repel each other rather than form clusters or patches. It is hypothesized that the patch formation phenomenon observed experimentally is due to the polymer phase segregation phenomenon. A determination of the driving forces involved in the formation process is necessary to gain a deep understanding of the process. This exploratory research aims to investigate the role that: 1) thermodynamic interactions such as polymer-solvent and polymer polymer-solvent play in the phase separation phenomenon and 2) the interfacial tension plays in the phase separation phenomenon.. At the fundamental level, this proposal will advance the self-assembly field by adding new knowledge to the phase separation phenomenon. In the past, the phase separation phenomenon has been observed, reported and discussed in systems such as binary self-assembly monolayers (SAM) of n-alkanethiols on gold, surfactant coated nanoparticles and surfactant-coated substrates, but not on the surface of polymeric particles. The PI is the first to report that the phase separation phenomenon also occurs in the presence of two different lipid-PEGylated functional groups. The full understanding of this phenomenon is critically relevant for the interaction between patchy particles and biological entities such as proteins, cells and tissues. These patchy particles have potential applications in drug and vaccine delivery.