Sol-Gel Entrapment of Enzymes

Abstract

Two enzymes, lipase and β-galactosidase, have been encapsulated within sol-gel matrices. Enzymatic activity of encapsulated lipase for hydrolysis and trans-esterification reactions is maintained. Encapsulation yields depend not only on the sol-gel porous texture but also on the water amount added for the sol-gel synthesis and the hydratation history of the enzyme. When the water amount is low, the highly active enzyme conformation generated by the phase separation is frozen during gelation. Escherichia Coli have been also encapsulated. The cellular organization appears to be well preserved. Their β-galactosidase activity seems to be better in wet gels but decreases dramatically upon drying.

Silica Nanocasting of Simple Cellulose Derivatives: Towards Chiral Pore Systems with Long‐Range Order and Chiral Optical Coatings

“…This is why most work is done on porous sol±gel silica, [5] which is easy to control and the final product, amorphous SiO 2 , is both easy to address and able to adapt to even the smallest structures. Templates other than surfactants that work well with silica usually contain OH±, NH 2 ±, or COOH groups, including (sorted by increasing pore size) sugars and carboxylic acids, [6,7] carbohydrate-based organogelators, [8] polyalginates, [9] proteins and other biomolecules, [10] viruses, [11] functional polymer latexes, [12] and whole cells and bacteria, [13,14] in the latter case keeping the bacteria functional. Recent examples for templates based on the compatibility between silica and oligosaccharides include characterization of the self-assembly of cyclodextrines [15] and the superstructures of cyclodextrine-based rotaxanes.…”

Sol-gel Chemistry in Medicinal Science

“…Although several attempts were reported on the use of oxygen electrodes [44,45], the most suitable approach relies on the detection of the redox reaction at the enzyme active site [46]. However, the direct electron transfer from the active site to the electrode is limited by its confinement and the poor conductivity of the silica gel [47].…”

Covalent immobilization of α‐amylase onto UV‐curable coating

“…Immobilization refers to the preparation of insoluble biocatalytic derivatives and involves the coupling of enzymes to solid supports that are either organic or inorganic. There are many advantages of the immobilization of proteins onto solid support2–4: Improve enzyme shelf‐life (half‐life); Improve stability in adverse reaction conditions; Improve stability in the presence of organic solvents; Easy separation from product stream; Allow continuous flow operations and repetitive usage; Increase enzymatic activity, in few cases. …”