(239a) Lab-on-a-Chip Device for Shear Enhanced Purification of Macro Biomolecules

Protein manufacturing required a multitude of sequential steps to achieve a desirable product. Briefly, the process spans two essential processes, namely, the formation of the target biomolecule (upstream) and the purification of the target protein (downstream). For most therapeutic applications, FDA recommends a high level of purity (99.99%) and hence, the purification processes consist of many non-trivial steps. Thus, protein purification is cumbersome, expensive and requires the meticulous application of each step to reduce potential loss of product. Furthermore, post purification, the process equipment often requires extensive, costly maintenance that needs harsh chemicals. Here we present a new methodology of using shear forces that offers an alternative approach to protein purification that reduces the number of steps, making it easier, greener, and less expensive. Furthermore, our method can be scaled according to the needs of the final product. Analogous to affinity chromatography, a stationary phase – Carbon Nanotubes (CNTs) - will be used in conjuncture with a mobile phase in lab-on-a-chip device setup. We have combined the lab-on-a-chip device with microelectrodes to perform Electrical Impedance Spectroscopy (EIS). EIS will be used to monitor any changes within the system (attachment/no attachment). Protein A is attached to CNTs using EDC-NHS chemistry. Post attachment, CNT’s are tightly packed in a microfluidic channel (akin to a packed bed reactor) and are held in place (against the fluidic drag force) by a transverse electric field from non-planar interdigitated electrodes. Preliminary data clearly shows that the CNTs are capable of generating shear forces close to hydrogen bond strength depending on several factors such as the microfluidic architecture and the flow velocity. At a low flow rate, the target proteins (monoclonal antibodies in our experiments) attach to Protein A while the rest of the solution flows by (filtration). The flow rate is then suitably modified to increase the shear force enough to release the biomolecules from the CNT complex into an elution buffer while maintaining their bio-functionality (purification). Hence, the shear force approach drastically reduces the number of steps required for the desired purification. Further post elution buffer, prolonged washing with a solution allows us to regenerate the CNT’s for the next round of purification. We have developed optimal conjugation protocols for the process, and have studied in details the effect of fluid flow, pH, and temperature on the purification efficacy of our platform. We believe that this technology not only benefits the protein manufacturing scene in general (i.e., the production of mainstream proteins such as insulin), but also other contemporary, specific applications such as using monoclonal antibodies from cancer treatment to sensors.