Fabrication and assembly of multi-layered microstructures embedding cells inside microfluidic devices

Recently the research about constructing 3 dimensional cell structures is very important for its great potential applications in tissue engineering. In this paper, we report a novel method of constructing multi-layered microstructures embedding cells via microfluidic devices. The on-chip fabrication of movable microstructures embedding fibroblasts (NIH/3T3) based on Poly (ethylene glycol) Diacrylate (PEGDA) was reported. Two approaches for assembling these movable microstructures were presented. One was a manual assembly method based on micromanipulation system and the other one was a self-assembly method based on microfluidic channel. Several manual assembly ways were demonstrated and a tube-shaped microstructure with 17 layers was assembled by an efficient assembly method. A novel microfluidic channel was presented for conducting self-assembly method and a 2-layered experimental microfluidic device was fabricated by Polydimethylsiloxane (PDMS). The self-assembly process of fabricated microstructures via this device was preliminarily demonstrated.