"Fabrication of 3D Tissue Chips Using a Layer-by-Layer Technique"
Mitsuru Akashi, PhD - Osaka University
A Layer-by-Layer (LbL) assmebly is an appropriate method to fabricate nanometer-sized films on a substrate through alternate immersion into interactive polymer solutions. The LbL hierarchic construction of films can be achieved by introducing heterogeneous polymers, resulting in novel polymer blend systems. We focused on the fabrication of stereocomplex LbL films by van der Waals interactions and the construction of biocompatible hollow capsules for drug delivery system by LbL assembly. The multilayered films with tuneable physic-chemical properties prepared by LbL assembly have great potential for varied applications.
The creation of artificial three-dimensional (3D) tissues possessing a similar structure and functions as natural tissue is a key challenge for implantable tissues in tissue engineering, and for model tissues in pharmaceutical assay. Recently, we demonstrated a simple 3D-cell manipulation technique for the construction of hierarchically layered structures, which possess a precisely controlled layer number and type of cells, by the direct fabrication of a fibronectin (FN)-gelatin (G) nanofilm like an ECM on the surface of each cell layer. Since the FN-G nanofilms with over 6 nm thick acted as a scaffold for the cell adhesion of the second layer, we successfully developed hierarchical cellular multilayers composed of various type of cells, such as human primary fibroblasts, mouse C2C12 myoblasts, rat primary cardiac myocytes, and human primary smooth muscle cells, even 10 layers In addition, blood vessel model tissues with varied layer numbers composed of human smooth muscle cell (UASMC) and human endothelial cell (HUVEC) were also fabricated by this technique. These hierarchical structures would be useful as a 3D-layered model tissue for tissue engineering and pharmaceutical assay.
Reference: Michiya Matsusaki, Koji Kadowaki, Yoshio Nakahara, Mitsuru Akashi, “Fabrication of Cellular Multilayers with Nanometer-Sized Extracellular Matrix Films”, Angew. Chem. Int. Ed., 46, 4689-4692 (2007).