Collaborative Research: Laser-Assisted Orifice-Free Fabrication of Viscous Alginate Microspheres

这项合作研究的目的是测试的假设，具有均匀尺寸的封装微球可以可控地制造从一个高粘度的流体系统，使用一种新的方法，而不是基于使用的孔。基于孔的技术限制了从粘性流体快速生产不同尺寸微球的灵活性。利用金属箔作为动态释放层的激光辅助无摩擦制造技术将特别适用于粘度为100 mPa·s或更高的流体。主要研究活动包括：1）使用从时间分辨成像研究和数学建模中获得的过程动力学知识，演示和优化拟议的激光辅助前向转移技术; 2）阐明激光辅助制造封装微球的流体动力学。海藻酸钠将被用作包封活细胞的模型流体。特别地，将大鼠内皮细胞悬浮液作为待包封的代表性活性成分添加到海藻酸钠溶液中。本研究的成功将为利用金属箔辅助的激光前向转移技术制备粘性微球提供新的思路。粘性封装微球尺寸的精确控制在制造中具有重要意义，因为尺寸分布可以决定大多数微球应用（例如组织工程和药物递送）的成功。更广泛的影响还将包括一个训练有素的学生准备从事科学，技术，工程和数学学科的职业管道。利用本研究获得的新知识，将进一步开发生物医学制造和生物材料加工课程，让学生了解制造技术的最新进展。

The objective of this collaborative study is to test the hypothesis that encapsulated microspheres with a uniform size can be controllably fabricated from a highly viscous fluid system using a novel process not based on the use of an orifice. Orifice-based techniques limit the flexibility in rapidly producing different size microspheres from viscous fluids. The laser-assisted orifice-free fabrication technique, utilizing a metallic foil as the dynamic release layer, will be especially suitable for fluids with a viscosity on the order of 100 mPa's or higher. Key research activities include 1) demonstrating and optimizing the proposed laser-assisted forward transfer technique using the process dynamics knowledge gained from a time-resolved imaging study and mathematical modeling; and 2) elucidating the fluid dynamics of the laser-assisted fabrication of encapsulated microspheres. Sodium alginate will be used as a model fluid to encapsulate living cells. In particular, rat endothelial cell suspension will be added to the sodium alginate solutions as a representative active ingredient to be encapsulated. The fabricated microspheres will be experimentally evaluated in terms of physical and biological properties.Success in this research will expand the knowledge for viscous microsphere fabrication using metallic-foil assisted laser forward transfer. The precise control of viscous encapsulated microsphere size is of great manufacturing importance since the size distribution can determine the success in most microsphere applications such as tissue engineering and drug delivery. Broader impacts also will include a pipeline of well-trained students ready to undertake careers in Science, Technology, Engineering, and Mathematics disciplines. With the new knowledge gained from this study, Biomedical Manufacturing and Processing of Biomaterials courses will be further developed to expose students to state-of-the-art advances in manufacturing technologies.