(765c) Demonstration of Size Selective Protein Capture and Protection From Protealytic Hydrolysis

Active protein capture has great potential in biological catalytic, separation and drug delivery applications. In recent years, significant interest and resources have been placed on the development of materials platforms for the delivery of therapeutic enzymes.  Problems have arisen in the development of these materials regarding the implementation of finely tunable and accessible enzyme supports as well as protection of valuable cargo in enzyme hydrolyzing environments. Prevention of protein denaturation and degradation in biological environments is critical to developing bioactive interfaces and devices. Micelle templated porous spherical silica materials with finely tunable pore sizes are synthesized and investigated as a versatile protein capturing support. These materials are prepared by precipitation of silica precursors in the presence of Pluronic (PEO)-(20)-(PPO)-(70)-(PEO)-(20) triblock copolymer surfactant P123 with pore tuning by changing the hydrothermal treatment temperature. Finely tunable pores with sizes ranging in diameter from 3 to 12 nanometer are prepared. The morphology is also tuned to provide large (~15 µm) mostly spherical particles amenable to visualization by scanning confocal microscopy. The sustained activity of the captured proteins in the presence of hydrolyzing proteases will be used to demonstrate the protective capabilities of these materials. As a model system, enhanced green fluorescent protein (EGFP) is used as a representative protein; The activity of EGFP can be compromised by either protealytic degradation or denaturing in solution. Variable pore sizes will be used to demonstrate the effect of pore size on the accessibility and protective capabilities of size selective pockets.