'Swell gels' boost enzyme performance

Enzymes are commonly added to laundry detergents and liquid soaps to help digest stain-causing proteins, and they also are added to shampoos to boost the shine and thickness of hair. Bakul C. Dave of Southern Illinois University, Carbondale, and his colleagues there and at Genencor International now report a method to trap enzymes in silica gel beads, which allows controlled release of the enzymes for improved performance and is expected to extend the shelf life of many consumer products (Adv. Mater. 2006, 18, 2009). Enzymes are sensitive to denaturation and/or aggregation in detergents and at warm temperatures, but the researchers figured encapsulating enzymes in an organosilica sol-gel system would help protect them. The team explored several types of beads synthesized from the precursor bis[3-(trimethoxysilyl)propyl]ethylenediamine. The enzymes remain trapped and stable in the beads, which quickly swell in water to release the enzymes for maximum effectiveness. The patented "swell gels," as they are called, were tested in commercial laundry products and are being considered by Genencor for commercial applications.