Immobilization of enzymes for medical uses on plastic surfaces by radiation‐induced polymerization at low temperatures

Abstract

The immobilization of some medically useful enzymes were studied by means of radiation-induced polymerization at -78 degrees C. Glucose oxidase and glucose peroxidase were immobilized in the form of thin membranes inside polyvinyl chloride tubes and on polyethylene films; these membranes showed considerable activity yield, as well as good activity retention. Two effective methods were adopted to improve the surface properties of the base materials and to facilitate firm immobilization by coating: that is, an undercoating method followed by radiation curing of the undercoating and an irradiation grafting method with a monomer. Both were tested with good results. An immobilization of urokinase was also carried out successfully by similar methods. The thrombogenicity of the immobilized urokinase showed a remarkable effect on thombus formation.

Surface Macromolecular Microarchitecture Design: Biocompatible Surfaces via Photo-Block-Graft-Copolymerization Using N,N-Diethyldithiocarbamate

“…Antithrombogenic surfaces are obtained by the immobilization of biologically active substances with antithrombogenic activity, such as heparin, − urokinase, − prostaglandin derivatives, and human thrombomodulin. , Heparin immobilization has been achieved via ionic complex formation of heparin on cationically chargedpolymer substrates. , Release of heparin from the surface with time into blood eventually occurs, exposing the cationic polymer surface to the blood, which may cause massive platelet adhesion and aggregation resulting from electrostatic interactions with the exposed cationic charged surface. If a cationic graft polymer complicated with heparin is completely shielded or overlayered by a nonionic water-soluble polymer layer, cell adhesion on the device surfaces may be passively suppressed even after the heparin is completely released.…”

Preparation of polymeric biomaterials with the aid of radiation-chemical methods

“…The immobilisation of glucose oxidase, glucose peroxidase, and urokinase on the inner surfaces of poly(vinyl chloride) tubes and on LDPE films has been described. 249 The immobilisation method consists in the preliminary radiation-induced polymerisation of 2-hydroxyethyl methacrylate and the subsequent decomposition on the grafted surface of a mixture of the monomer with an aqueous solution of the enzyme. The tube is frozen and irradiated at 778 8C (dose 5 kGy).…”

“…307 ± 312 Methods whereby immobilised antitumour preparations can be produced have been described in detail in a series of studies. 204,205,249,276,278,313,314 The low-temperature polymerisation of diethylene glycol dimethacrylate mixed with various polymers [polystyrene, polyvinylformal, poly(ethylene glycol), poly(methyl methacrylate)] is used for the immobilisation of mitomycin, 5-fluorouracil, and bleomycin. It is emphasised that irradiation must be carried out in an oxygen-free medium and the dose must not exceed 10 kGy.…”

Photochemical Activation of Polyvinyl Chloride for Immobilization of Invertase

“…These membranes showed considerable retention activities. Immobilization of urokinase was also carried out successfully by similar method (6).…”