The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project will be to develop an enzyme immobilization platform to be used in the production of biopharmaceuticals and other biomanufacturing processes to reduce the timeline and cost associated with discovering and manufacturing biotherapeutics. Biopharmaceutical sales have soared in recent years and healthcare authorities have increased pressure on pharmaceutical manufacturers to reduce the cost of biologics leaving pharmaceutical engineers to focus on reducing bioproduction costs. To accomplish this goal, pharmaceutical companies are aggressively investigating continuous processing technologies to reduce the capital and other costs associated with biopharmaceutical manufacture. The immobilization platform described in this proposal will provide a technology that is compatible with continuous processing strategies to reduce the timeline and cost associated with discovering and manufacturing biotherapeutics. In addition, this platform has the potential to reduce the cost and increase the efficiency of biomanufacturing processes across several other industries including food, leather, and textiles. The intellectual merit of this SBIR Phase I project is to develop pH responsive immobilized enzymes for the production of biopharmaceuticals. There are three key technical challenges associated with this project: The immobilized-enzyme must demonstrate pH responsive behavior compatible with biologics manufacture (pH 6-7); mass transfer of protein substrates must be comparable to the native enzyme; and extended shelf-life of the immobilized-enzyme is required for long-term storage. To mitigate these challenges, this project aims to covalently bind an enzyme to a pH responsive polymer that is formulated to have reversible solubility near neutral pH. The solubility of the immobilized-biocatalyst can be tightly controlled within a specified pH range allowing for continuous processing and facile purification of the biotherapeutic product. Poor mass transfer often results from immobilizing biocatalysts on solid supports. These challenges are further exaggerated in bioconjugation reactions because the coupling partner, a protein, is generally more affected by sterics than small molecules. Therefore, fabrication of the solid support will be explored to produce resins of varied size, morphologies, and dissolution properties that are compatible with macromolecule functionalization. Additionally, the immobilized enzyme generated in this project can be utilized under soluble conditions, which combines the positive attributes of both immobilization and soluble enzyme catalysis. The final challenge of developing a commercially viable shelf-life of the catalyst will be addressed through development of novel drying protocols. Shelf-stable immobilized enzymes will be developed so that inventory can be maintained without requiring long lead times for catalyst production. 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.