Immobilization of enzymes and antibodies to radiation grafted polymers for therapeutic and diagnostic applications

State of Water, Molecular Structure, and Cytotoxicity of Silk Hydrogels

“…The role of water molecules in hydrogels has been investigated by many researchers, with the result that bound (nonfreezing), bulk (freezing), and intermediate (freezing bound) water have been shown to exist in hydrogels. − Differential scanning calorimetry (DSC) and NMR relaxometry have been used as typical methods to characterize and distinguish the state of water molecules in polymeric hydrogels. , The difference in state of water in organisms has been suggested to affect various aspects of biological structures, including their size, in bacterial and vegetative cells. − The bulk water is not crucial for enzymatic hydration, whereas the bound water plays an important role in enzymatic catalysis. , The biological activities of enzymes and proteins have been reported to depend on how the water molecules associate with these bioactive molecules, that is, the activities depend on the bound water content of the enzymes and proteins . The bound water content has been considered a significant factor in the control of drug release rate as well as enzymatic activity in hydrogel-based biomaterials . Although these previous studies have indicated that the state of water in hydrogels used as biomaterials therefore must influence their biocompatibility and biological response, the relationship between the state of water and the cytotoxicity of hydrogels has not been completely clarified until now.…”

Hollow‐Fiber Enzyme Reactor Operating under Nonisothermal Conditions

“…To attach the enzyme to a hydrophobic membrane, unable "per se" to bind proteins, the membrane is treated by means of the grafting technique. By this technique (10)(11)(12)(13)(14), radicals are induced onto the support and appropriate monomers are copolymerized onto it. Once grafted, the membranes are activated by means of different methods by considering the nature of the amino acid residues of the enzyme involved in the attachment procedure.…”

Enzyme Immobilization in Biodegradable Polymers for Biomedical Applications

“…Adsorption techniques have been used to immobilize asparaginase onto hollow fibers after first coating the fibers with albumin and then crosslinking the enzyme with glutaraldehyde. 41,126 Maciel and Minim 43 also reported that the use of L-asparaginase covalently attached to nylon tubing may constitute a useful system to be used in clinical applications.…”

“…However, some limitations have been attributed to the use of immobilized enzymes in biomedical applications, such as mass transfer resistances (substrate in and product out), adverse biological responses of enzyme support surfaces (in vivo or ex vivo), fouling by other biomolecules, greater potential for product inhibition, and sterilization difficulties. 126,137 Although the preparation of sterile immobilized enzyme systems may be complex, sterilization may be achieved by filtrating all the reagents and protein solutions through 0.2-mm filters and working under aseptic conditions.…”