# US 4,396,716 A · Preparation of biocompatible materials by immobilization of apyrase

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- Number: US 4,396,716 A
- Document ID: US4396716A
- Status: Granted
- Kind: A
- Application number: 06/334,907
- Filed: 1981-12-28
- Granted: 1983-08-02
- Earliest claimed: 1979-08-01
- Assignees: E.N.I. Ente Nazionale Idrocarburi
- Inventors: Walter Marconi; Francesco Bartoli; Francesco Pittalis
- Web page: https://patentgrep.com/patent/US4396716A

## CPC

- C12N 11/00: Carrier-bound or immobilised enzymes; Carrier-bound or immobilised microbial cells; Preparation thereof
- A61L 33/0047: {Enzymes, e.g. urokinase, streptokinase}
- C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00)
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)

## Abstract

A prosthetic polymer material is made non-thrombogenic by immobilizing apyrase on its surface. Immobilization is preferably carried out by hydrolytically activating the surface of a polyamide polymer or a polyethylene terphthalate polymer, and treating the hydrolyzed polymer with a solution of cross-linking agent and a solution of apyrase. The apyrase converts adenosine diphosphate to adenosine monophosphate and adenosine whereby the formation of thrombi is inhibited.

## Claims

### Claim 1

A method for preparing a non-thrombogenic apyrase-carrying prosthetic plastic material comprising the steps of hydrolytically activating the surface of a plastic material carrier selected from the group consisting of a polyamide polymer and a polyethylene terephthalate polymer, treating the hydrolyzed plastic carrier by immersing it into a buffered solution of a cross-linking agent selected from the group consisting of glutaraldehyde and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide and in a buffered solution of apyrase, and allowing said immersed plastic material carrier to stand for a time sufficient to effect the covalent bonding of apyrase to the surface of said plastic material carrier.

### Claim 2 (depends on 1)

The method of claim 1 wherein said plastic material carrier is a polyamide and said hydrolysis is an acid hydrolysis.

### Claim 3 (depends on 1)

The method of claim 1 wherein said plastic material carrier is polyethylene terephthalate, said hydrolysis is an alkaline hydrolysis, and said solution of a cross-linking agent is a buffered solution of N-ethyl-N'-(dimethylaminopropyl)carbodiimide, which solution is combined with said buffered solution of apyrase prior to the immersion therein of said hydrolytically-activated plastic material carrier.

### Claim 4 (depends on 1)

Non-thrombogenic apyrase-carrying prosthetic plastic material articles prepared by the method of claim 1 consisting of plastic material from the group consisting of polyamides and polyethylene terephthalate having said apyrase covalently and permanently bonded on the surface thereof.