Graduate Student Award Session:Covalent Immobilization of Chymotrypsin within Zwitterionic Poly(carboxybetaine) Microscale Hydrogels

Enzymes are incredibly useful in medicine and industrial chemistry. Use of enzymes, however, is limited by poor stability, short half-life, and difficulties with reusability. There is emerging evidence that biocompatible zwitterionic materials can prevent non-specific interactions within proteins systems and increase protein stability. Here, zwitterionic microscale hydrogels were synthesized from poly (carboxybetaine methyl methacrylate), pCB, using an inverse emulsion, free radical polymerization reaction technique. Microscale hydrogels were loaded with a model enzyme, α-chymotrypsin (CT), using a post-fabrication loading technique. A reaction scheme was developed and studied for covalent immobilization of CT within the microscale hydrogels. Confocal laser microscopy was used to investigate the distribution of immobilized CT. The immobilized CT esterase enzymatic activity has been studied and compared to free CT in buffer. Activity studies were carried out at different pH and temperature conditions to evaluate the effects of immobilization on enzyme activity. Further, the conformational stability and half-life of the immobilized and free enzymes were compared. This research paves the way for fabrication of enzyme immobilized materials with extend enzyme lifetime and molecular turnover.