3D Printed Microfluidic Devices for Drug Release Assays.

Microfluidics research for various applications, including drug delivery, cell-based assays and biomedical research has grown exponentially. Despite this technology's enormous potential, drawbacks include the need for multistep fabrication, typically with lithography. We present a one-step fabrication process of a microfluidic chip for drug dissolution assays based on a 3D printing technology. Doxorubicin porous and non-porous microspheres, with a mean diameter of 250µm, were fabricated using a conventional "batch" or microfluidic method, based on an optimized solid-in-oil-in-water protocol. Microspheres fabricated with microfluidics system exhibited higher encapsulation efficiency and drug content as compared with batch formulations. We determined drug release profiles of microspheres in varying pH conditions using two distinct dissolution devices that differed in their mechanical barrier structures. The release profile of the "V" shape barrier was similar to that of the dialysis sac test and differed from the "basket" barrier design. Importantly, a cytotoxicity test confirmed biocompatibility of the printed resin. Finally, the chip exhibited high durability and stability, enabling multiple recycling sessions. We show how the combination of microfluidics and 3D printing can reduce costs and time, providing an efficient platform for particle production while offering a feasible cost-effective alternative to clean-room facility polydimethylsiloxane-based chip microfabrication.