Fundamental studies of adhesion phenomena involving vesicles

囊泡是微米或纳米大小的颗粒，在结合膜的帮助下将有限体积的液体隔开。以水泡为基础的产品，如织物柔软剂、护肤霜、发胶，以及治疗药物，如多喜(化疗)和两性霉素(抗真菌)，加在一起构成了全球数十亿美元的业务。然而，由于这些产品的许多开发都是反复试验、以实验为重点的性质，对于哪些因素将导致更少的原材料消耗、更有效的资源利用、更低的环境影响和更好的产品功能，仍然缺乏基本的了解。该项目是朝着发展对上述关系的系统理解迈出的第一步。特别是，我们专注于一种现象，它支配着基于囊泡的产品的优化-囊泡粘连(即，囊泡粘连)。水泡粘连是乳液和治疗剂等产品发挥功能的关键步骤，另一方面，它对织物柔软剂等产品也是一种威胁，并导致这些产品中的活性物质结霜或沉淀。在这个项目中，我们将开发两个工具来表征囊泡粘连现象。一种是称为微流控四辊磨的流动装置，它将帮助我们了解流动是如何诱导或防止囊泡粘连的。另一种装置是作用力装置，它确定一个小泡与一个表面或另一个小泡结合的强度或强度。该项目的理论部分将制定模型和模拟，以预测增强或防止囊泡粘连的条件。该项目的工具和成果将影响囊泡产品行业以外的广泛领域。生物细胞与表面之间的相互作用在血液流动、免疫反应机制、细胞内和细胞间转运、药物输送和组织工程等方面具有重要意义。我们的工具还将适用于设计乳化系统，这些系统广泛应用于食品、植物油和石油行业，这些行业都是加拿大价值数十亿美元的行业。

Vesicles are micron or nanometer-sized particles which compartmentalize a finite volume of liquid with the help of a bounding membrane. Vesicle-based products such as fabric softeners, skin creams, hair lotions, and therapeutics such as Doxil (chemotherapeutic) and Amphotericin (antifungal) together constitute a multi-billion dollar business worldwide. However, due to the trial-and-error, experimentally-focused nature of development of many of these products, a fundamental understanding of what factors would lead to lesser raw material consumption, more efficient resource usage, lower environmental impact and better product function is still lacking. This project represents a first step towards the development of a systematic understanding of the above relationships. In particular, we focus on one phenomenon that governs optimization of vesicle-based products - vesicle adhesion (i.e. vesicle sticking). Vesicle adhesion is a crucial step in the function of products such as lotions and therapeutics; on the other hand, it is a menace for products such as fabric softeners, and leads to creaming or settling of the active material in these products. In this project, we will develop two tools that will characterize vesicle adhesion phenomena. One is a flow device called the microfluidic four-roll mill, which will help us understand how flow induces or prevents the adhesion of vesicles. The other device is a force apparatus, which determines how strongly or weakly a vesicle binds to a surface or another vesicle. The theoretical component of this project will formulate models and simulations that will predict the conditions which enhance or prevent vesicle adhesion. The tools and results from this project will impact a wide variety of fields other than vesicle-product industries. The interactions between biological cells and surfaces with and without flow have implications in blood flow, immunological response mechanisms, intra and intercellular transport, drug delivery and tissue engineering. Our tools will also be applicable for designing emulsion systems which are prevalent in the food, vegetable oil and petroleum industries, all billion dollar industries in Canada.