Experiment and Modeling of Enzymatic Degradation Kinetics Using Autofluorescent BSA Microspheres

Autofluorescent bovine serum albumin (BSA) hydrogel microspheres are synthesized through spray-drying of glutaraldehyde cross-linked BSA nanoparticles. The as-synthesized microspheres are employed for the study of enzyme degradation in an aqueous solution. Experimental results from confocal imaging and phenomenological modeling are presented to quantify the degradation process as well as the release of synthesized fluorophores. The coupling of swelling dynamics of the gel and the transient distribution of fluorophores are optically tracked. It is found the concentration of the enzyme proteinase K within the Tris buffer plays the primary role that controls BSA gel degradation. The model considers linear elastic deformation of the hydrogel coupled with fluorophore transport and enzyme degradation kinetics. The study provides fundamental investigation of the degradation and release kinetics of protein-based materials, which can potentially be extended to in vivo applications in drug delivery or tissue engineering.