Evaluation of various membranes at different fluxes to enable large-volume single-use perfusion bioreactors.

The growing demand for biological therapeutics has increased interest in large-volume perfusion bioreactors, but the operation and scalability of perfusion membranes remain a challenge. This study evaluates perfusion cell culture performance and monoclonal antibody (mAb) productivity at various membrane fluxes (1.5-5 LMH), utilizing polyvinylidene difluoride (PVDF), polyethersulfone (PES), or polysulfone (PS) membranes in tangential flow filtration mode. At low flux, culture with PVDF membrane maintained higher cell culture growth, permeate titer (1.06-1.34 g/L) and sieving coefficients (≥83%) but showed lower permeate volumetric throughput and higher transmembrane pressure (TMP) (>1.50 psi) in the later part of the run compared to cultures with PES and PS membrane. However, as permeate flux increased, the total mass of product decreased by around 30% for cultures with PVDF membrane, while it remained consistent with PES and PS membrane, and at the highest flux studied, PES membrane generated 12% more product than PVDF membrane. This highlights that membrane selection for large-volume perfusion bioreactors depends on the productivity and permeate flux required. Since operating large-volume perfusion bioreactors at low flux would require several cell retention devices and a complex setup, PVDF membranes are suitable for low-volume operations at low fluxes whereas PES membranes can be a desirable alternative for large-volume higher demand products at higher fluxes.

Pioneering Just-in-Time (JIT) Strategy for Accelerating Raman Method Development and Implementation for Biologic Continuous Manufacturing.

Raman spectroscopy is a popular process analytical technology (PAT) tool that has been increasingly used to monitor and control the monoclonal antibody (mAb) manufacturing process. Although it allows the characterization of a variety of quality attributes by developing chemometric models, a large quantity of representative data is required, and hence, the model development process can be time-consuming. In recent years, the pharmaceutical industry has been expediting new drug development in order to achieve faster delivery of life-changing drugs to patients. The shortened development timelines have impacted the Raman application, as less time is allowed for data collection. To address this problem, an innovative Just-in-Time (JIT) strategy is proposed with the goal of reducing the time needed for Raman model development and ensuring its implementation. To demonstrate its capabilities, a proof-of-concept study was performed by applying the JIT strategy to a biologic continuous process for producing monoclonal antibody products. Raman spectroscopy and online two-dimensional liquid chromatography (2D-LC) were integrated as a PAT analyzer system. Raman models of antibody titer and aggregate percentage were calibrated by chemometric modeling in real-time. The models were also updated in real-time using new data collected during process monitoring. Initial Raman models with adequate performance were established using data collected from two lab-scale cell culture batches and subsequently updated using one scale-up batch. The JIT strategy is capable of accelerating Raman method development to monitor and guide the expedited biologics process development.