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

1348112PI：Morales这个热切的奖项支持一项研究计划，该计划旨在探索聚合物热力学在聚合物核心上形成补丁的作用。PI最近发现了一种新的片状粒子的形成，这种片状粒子具有独特的核壳结构，由中空的疏水聚合物核和由单个或双个基于脂质-聚合物的贴片组成的片状表面组成，这些贴片独立地分布在核心的表面并定向。斑块的形成机制尚不清楚。在聚合物核上形成斑块是一种有点出乎意料的现象，因为在中性pH下具有正电荷的胺基团预计会相互排斥，而不是形成簇或斑块。假设实验中观察到的斑块形成现象是由聚合物相分离现象引起的。确定形成过程中涉及的驱动力对于深入了解这一过程是必要的。本探索性研究旨在探讨：1)聚合物-溶剂、聚合物-溶剂等热力学相互作用在相分离现象中的作用；2)界面张力在相分离现象中的作用。在基本层面上，这一提议将通过为相分离现象添加新的知识来推动自组装领域的发展。过去，人们观察、报道和讨论了相分离现象，如正硫醇在金表面的二元自组装单分子膜、表面活性剂包覆的纳米粒子和表面活性剂包覆的衬底，而不是在聚合物粒子的表面。PI首次报道了在存在两个不同的脂质-聚乙二醇化官能团时也会发生相分离现象。对这一现象的充分理解对于片状颗粒与蛋白质、细胞和组织等生物实体之间的相互作用至关重要。这些斑驳的颗粒在药物和疫苗输送方面有潜在的应用。

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.