PFI-TT: Improved microfluidic devices for protein crystallization and x-ray diffraction

Brandeis University, Waltham MA

Investigators

Abstract

The broader impact/commercial potential of this Partnerships for Innovation - Technology Translation (PFI-TT) project is in the improvement of structure-based drug design, a valuable pharmaceutical discovery tool, to accelerate discovery, reduce development costs, and boost the strength of the ultimately selected drug candidate. A critical step in this process is the accurate understanding of the three-dimensional structure of the drug target, in the presence or absence of the potential drug candidate. Currently, a method called X-ray crystallographic analysis is the most important way to determine structure, but it is expensive to operate. Two devices will be developed - one, to make small vessels to test many types of drug chemistries simultaneously, and another for better studies of the structure. Compared to current technologies, the microfluidic devices will perform better and be easier to operate, at a reduced cost. The proposed project will lead to commercialization of two microfluidic devices. The first, intended for the high-throughput screening of protein crystallization conditions, will be developed with the following features: (a) ability to screen 400 different conditions per square centimeter using counter-diffusion, (b) no cross-contamination, (c) consumes less than 10 nanoliters protein per condition, (d) low cost to manufacture and operate, and (e) improved performance over existing technologies. The technical innovation of this device is to use passive capillary valves operating with minimal external control to sequence fluid flow and create isolated storage compartments. A second device will be developed to produce crystals optimized for X-ray diffraction using a novel feedback mechanism to separate protein crystal nucleation from growth. The device will be manufactured from a low molecular weight thermoplastic, allowing on-chip serial diffraction from hundreds of identical crystals thereby avoiding expensive and time consuming cryoprotection. This will improve screening of crystallization conditions, optimize the rate of crystallization, reduce the amount of protein and eliminate laborious crystal processing steps. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.