Injection-Molded Plastic Array for 3D Culture Tissue (IMPACT) Platform

Abstract

Polydimethylsiloxane (PDMS) has been widely used in fabricating microfluidic devices for prototyping and proof-of-concept experiments. Due to several material limitations, PDMS has not been widely adopted for commercial applications that require large-scale production. This paper describes a novel Injection-Molded Plastic Array 3D Culture Tissue (IMPACT) platform that incorporates microfluidic design to integrate patterned 3D cell culture within a single 96-well. Mass production compatible material polystyrene (PS) is injection molded with liquid guiding structures to obtain multiple hydrogel patterns. Cell containing gels can be sequentially assembled by utilizing capillary-guided flow along wedges and narrow gaps designed within the 96-well form factor (diameter = 9 mm). Compared to PDMS-based hydrophobic burst valve designs, this work utilizes hydrophilic liquid guides to obtain rapid and reproducible patterned gels. When a liquid droplet (i.e. cell containing fibrin or collagen gel) is placed on any part of the wedge structure, spontaneous patterning is achieved within 1 second. Optimal dimensionless parameters required for successful capillary loading have been determined. The IMPACT platform was used to co-culture HUVEC and LF, and to obtain angiogenic sprouts with open lumen and tip cells that are comparable to those observed in PDMS based devices. This platform is expected to have a wide range of applications related to biological discovery, tissue engineering and drug screening, and can be used in a variety of scales from lab bench to automated equipment.