Fabrication of Plla Microtube Array (Mta) via Electrospinning --- the Array Formation of Poly-L-Lactic Acid/ Polyethylene Glycol, (Plla/Peg) Micro Shell /Core Fibers

The objective of this study is to investigate the formation mechanism of a novel electrospun PLLA microtube array (MTA) and construct operational map for future applications. An interesting, epitaxial-like packing of electrospun fibers was observed during the preparation of the PLLA hollow fibers in our laboratory. An array of microtube membrane was obtained with several unique structural characteristics, such as high degree of fiber alignment, tens to hundreds of one-by-one connected fibers, and as a standing alone membrane. These core/shell fiber can also made hollow by washing off water soluble core component. This unique structure closely mimics the structure of several natural tissues, especially for those with high directional characteristics, such as nerve, vascular and hair tissues, therefore, of potential tissue engineering scaffolds application. Our preliminary data suggested this fabrication process could be controlled by few operational variables, such as applied field strength, collection speed, flow rate, and flow rate ratio. The properties of polymeric solutions, such as conductivity, viscosity and surface tension are also factors affecting MTA formation. However, even we could reasonably control some of above mentioned parameters and prepare such unique structure; it is still unclear the detail formation mechanism and its production limitation. It is then our strong intention to explore theoretically the principle behind this phenomenon and systematically investigate the relationships between operational variables and properties of resulted MTA through force and mass balances of the electrospun fiber. With established theoretical equation, we will verify it with experimental results collected via high speed video capture system. Finally, working maps will be build for precise fabrication of this unique MTA structure for future applications.