Abstract

Biofabrication of Three-Dimensional (3D) Cell-Laden Constructs by Thermoresponsive Release of Photo-Patterned Hydrogels

Xiaolei Nie, Research Fellow, Singapore University of Technology and Design

Two-dimensional (2D) photopatterning is advantageous in fabricating cell-laden grafts [1], but upscaling such engineered grafts to physiologically relevant sizes requires a systematic fabrication process. This work demonstrated the fabrication of versatile multi-cellular co-culture constructs by photopatterning cell-laden hydrogels on a poly(N-isopropylacrylamide) (PNIPAAm)-coated surface. Cell-laden grafts of arbitrary 2D shapes were initially photopatterned on a thermoresponsive substrate. The patterned grafts were incubated as static or floating cultures for weeks to months before the assembly into 3D structures. Using this method, we demonstrated (1) large-scale fabrication of freestanding grafts of diverse patterns, (2) culture and harvest of millimetre-scaled grafts encapsulating two or three different types of cells and (3) assembly of the released grafts into bifurcated vascular structures. This approach uniquely combines photopatterning with PNIPAAm-coated surfaces to facilitate biofabrication. The versatility of this fabrication method offers the potential to create physiologically relevant tissue-engineered grafts with heterogeneous physical and chemical properties.