Microfluidic technique for the fabrication of hollow fibers and its biomedical application for in vitro endothelial blood brain barrier research

다국어 초록 (Multilingual Abstract)

This study reports the advanced and effective approach employing a triple-flow polydimethylsiloxane (PDMS) microdevice to controllably generate the alginate-based hollow fibers which are applicable to become a friendly microcappililaries-like scaffold for supporting human umbilical vein endothelial cells (HUVECs) development. The use of PDMS-based cyclindrical device could not only eliminate the limitations of complicated assembly by using a commercially plastic or steel-based microcapillary system, but also enhance the biocompatibility of cell supportive scaffolds. The two PDMS replicas with semi-cylindrical microchannel were successfully assembled to eventually obtain the completed microchannel with circular cross section which permitted the coaxial flows formation for a mild and continuous hollow fiber fabrication without channel clogging. The mineral oil introduced into the central flow that served as an inert space inside the Ca-alginate wall to ensure the formation of hollow fibers obtained a consistent hollow structure. The hollow fibers owning the robust mechanical strength and high permeability with reasonable biocompatibility were used as scaffolds for the attachment and proliferation of HUVECs to mimic brain microcappilaries. The hollow fibers covered with a full layer of HUVECs were further integrated in a neurovascular construction to co-culture with astrocytes for mimicking blood brain barrier. The use of introduced neurovascular model for drug testing exhibited a great prospective in tissue engineering and drug delivery.

목차 (Table of Contents)

• CHAPTER 1. INTRODUCTION ....................................................................1
• CHAPTER 2. MATERIALS AND METHODS .............................................5
• 2.1. Materials............................................................................................... 5
• 2.2 Fabrication of cylindrical triplet-flow microfluidic device................... 6
• 2.3 Generation of hollow fibers by using a microfluidic device................. 8
• 2.4 Structural characterizations of hollow fibers ........................................ 9
• 2.4.1 Morphology observation................................................................. 9
• 2.4.2 Mechanical strength of hollow fibers ............................................. 9
• 2.4.3 Mass transferring ability of hollow fibers .................................... 10
• 2.5 Cell seeding and culturing on hollow fiber ......................................... 10
• 2.6 Cell staining......................................................................................... 12
• CHAPTER 3. RESULTS AND DISCUSSION.............................................13
• 3.1 Controllable fabrication of hollow fibers ............................................ 13
• 3.2 Characterization of hollow fibers........................................................ 14
• 3.2.1 Morphology of hollow fiber ......................................................... 14
• 3.2.2 Mechanical strength of hollow fibers ........................................... 17
• 3.2.3 Fluid transportation inside the hollow fibers................................ 19
• 3.3 Cell viability and immunocytochemistry ............................................ 20
• 3.4 Characterization of BBB in neurovascular scaffold............................ 22
• 3.4.1 Fabrication of neurovascular scaffold with integrated hollow fiber
• ............................................................................................................... 22
• 3.4.2 FITC-dextran permeation test....................................................... 24
• CHAPTER 4. CONCLUSIONS ....................................................................27
• REFERENCES ..............................................................................................28
• ACKNOWLEDGEMENT .............................................................................31