Biochemically active sol-gel glasses: The trapping of enzymes

We describe the preparation and properties of a biochemically active sol-gel glass, obtained by the enzyme alkaline phosphate (ALP) in a polymerizing tetramethoxysilane. The immobilized purified ALP from bovine intestinal mucosa had a 30% activity yield and an improved stability to thermal deactivation compared to a solution. The composite bioactive glass was preserved in water at room temperature for two months without loosing activity. A non–Michaelis–Menten kinetics was observed. The concept of preparing bioactive materials by the sol-gel method seems to be general. Thus, other enzymes (chitinase, asparatase, β-glucose) were successfully trapped.