As an emerging rapid prototyping method, 3D-printing has recently caught tremendous attention. Scientists including Chengpeng Chen and his advisor, Dr. Spence, from Michigan State University have been taking advantage of 3D-printing to produce miniaturized fluidic analytical platforms. Chen et al recently reported a 3D-printed plastic platform for evaluating stored blood, which, as a front cover story, was published in the journal of Analyst (Analyst, 2014, 139, 3219-3226).
In the reported device, six parallel channels are fabricated on a single piece of platform which is able to perform high-throughput measurements. The device is designed at the same dimensions as a standard 96-well plate, and the wells on the platform are arranged at the appropriate locations as those on the 96-well plate, which facilitates it to use plate reader for signal readout. Apparently, 3D-printing is able to conveniently print out the platforms according to their designs produced by using the AutoCAD software. There are two types of wells fabricated on the platform: static wells for on-chip calibration and replaceable trans-membrane dynamic wells for sampling and analysis. The transmembrane well has a semipermeable membrane with 400-nm pore diameters on the well bottom. This well assembly can be simply inserted to the access hole initially printed on the platform. Under the transmembrane would be the blood sample flowing at optimal flow rates. The capability of the developed platform has been applied to the determination of ATP concentrations in the stored blood. In experiment, stored blood sample was pumped through the bottom channel where molecules such as ATP diffused through nano pores and entered the dynamic wells which contained a luciferin–luciferase mixture for ATP analysis. After circulating the blood for 20 minutes, the plate was moved to the plate reader for signal recording. Experimental results demonstrate that the reported platform is rugged, reusable, and capable of high-throughput analysis. The platform design and experimental technique are quite smart, which can potentially be adapted to other high-throughput biological analysis.
As a conclusion, the 3D-printing of fluidic platforms has advantages over soft lithography or other fabrication methods, and the device and technology developed by Chen et al have great potential as a tool for high-throughput analysis in research and clinical labs as well as in pharmaceutical industry.