Clinical study of urokinase‐bound fibrocollagenous tubes

Abstract

Dacron-reinforced fibrocollagenous tubes (FCT) were synthesized from canine mongrels using the mandril-rod technique in order to develop a small diameter (i.e., 4 mm i.d.) vascular graft. They were rendered fibrinolytic by immobilizing urokinase on to the inner surface of the tubes. Urokinase-bound fibrocollagenous tubes (UK-FCT), control FCTs (i.e., no bound enzyme), Perloff grafts (Dr. Perloff, Department of Surgery, University Medical Center, Sidney Australia, has developed a mandril-derived collagenous tube from goats. Samples were implanted for comparative purposes.) and autogeneous saphenous veins, were interposed in the carotid or femoral artery in chronic studies involving 21 canine mongrels. On the basis of Doppler auscultation and palpation, the UK-FCTs were statistically more patent than other candidate prostheses. Fibrin degradation product (FDP) increased in the dogs' systemic circulation with a postoperative peak of 5 days. The host's increase in fibrinolytic activity was shown to be local to the anastamosis. A carotid arterial extracorporeal shunt was designed to evaluate acute patency. Results indicated a rapid thrombosis but no platlet or fibrin adherence to the graft surface was observed, as evidenced by scanning electron microscopy.

Evaluation of biocompatibility of the surface of polyethylene films modified with various water soluble polymers using Ar plasma-post polymerization technique

“…1 in Tris buffer solution at 37 8C, varying the concentrations of S-2238 from 0.1 to 2.5 mmol N L -1 . It has been shown that thrombin catalyzes the hydrolytic scission of coagulation factor I (fibrinogen), VII, VIII or XIII at the carboxyl end of an arginine (Arg) residue adjacent to hydrophobic a-amino acid residues, [7] i. e., thrombin accelerates the conversion of Fib to fibrin monomer. S-2238 is hydrolytically catalyzed at the amido bond of containing carbonyl groups of Arg to release p-nitroaniline by thrombin as shown in Fig.…”

“…[6][7][8][9] In particular, since a hydrogel has physical properties similar to human tissue and may exhibit an excellent biocompatibility, a number of workers have made a significant effort to modify the surface of polymer substrates with hydrogel forming polymers such as poly [2-(methacryloyloxy)ethyl phosphorylcholine] (PMPC), [1,[10][11] poly [2-(glucosyloxy)ethyl methacrylate] (PGEMA), [2,3] polyoxyethylene (POE), [12] poly(N-isopropylacrylamide) (PNIPAAm) [13] and poly[N-(2-hydroxypropyl) methacrylamide] (PHPMA), [14,15] the structures are shown in Fig. 1.…”

Preparation of porous polymeric structures for enzyme immobilization

“…[3][4][5][6] Furthermore, the interest in the immobilized enzymes and their application to bioprocessing, 7,8 analytical systems, 9 and enzyme therapy 10 has steadily grown in the past decade. Thus, many approaches to the preparation of water-soluble enzymes have been explored [11][12][13][14] to study the enzyme reaction in biphasic systems similar to those existing in vivo.…”

Immobilization of Thiol Proteases onto Porous Poly(vinyl alcohol) Beads

“…2 • 3 A concerted or sequential reaction of several enzymes is also possible by the use of mixed or stratified beds. Furthermore, interest in immobilized enzymes and applications to bioprocessing, 4 • 5 analytical system, 6 and enzyme therapy 7 has steadily grown in the past decade. Thus, many approaches to the preparation of water insoluble enzymes have been explored in recent years 8 -10 to study enzyme reactions in biphasic systems similar to those in vivo.…”