Digital Light Processing 3D printing for biological applications of polydimethylsiloxane-based microfluidics

Soft lithography microfluidics offer many benefits over conventional biological assays; however, the impact this field is inhibited by the lack of widespread adoption of this technology in part due to prohibitive cost and fabrication time. Recent improvements in three-dimensional (3D) printing technologies such as digital light processing (DLP) printing offer a cost-effective and rapid prototyping solution to microfluidic fabrication. Limited information is available about how 3D printing parameters and resin cytocompatibility impact the performance of 3D printed molds for fabrication of polydimethylsiloxane (PDMS)-based microfluidics for cellular studies. Using a low-cost, commercially available DLP 3D printer, we assess the cytocompatibility of several resins, optimize printer settings and characterize minimum feature size of our system. We demonstrate the applications of DLP printing for soft lithography microfluidics by developing four assays to characterize cell viability, drug response, establish concentration gradients, and monitor live-cell 3D invasion into a hydrogel.