Patent US5505713A successfully refreshed from Google Patents.
US5505713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Indwelling catheter with stable enzyme coating
Assignee: Medtronic Minimed Inc
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Filing: 1994-04-01
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Granted: 1996-04-09
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Expires: 2014-04-01
Abstract
Abstract An improved indwelling catheter adapted for long-term usage includes a stable enzyme coating to prevent occlusion of the catheter lumen. The enzyme coating includes a fibrinolytic and/or lipolytic enzyme incorporated in a catheter coating to resist or control proteolytic degradation, thereby maintaining the enzyme in an active state for dissolving clots and occlusions within the catheter lumen over an extended period of time.
Inventors
- 👤 William P. Van Antwerp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:09
CPC Classifications
A; A61; A61L; A61L29/00; A61L29/08; A61L29/085; A61M; A61M25/00; A61M25/0017
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
115 words
A catheter, comprising: an elongated tubular element formed from a polymeric material and adapted for patient placement, said tubular element defining a catheter lumen; and a surface coating applied to said tubular element on at least a portion of the surface thereof, said surface coating including at least one enzyme effective to dissolve occlusions along said catheter lumen, said at least one enzyme comprising a lipolytic enzyme, and means for protecting said enzyme against short-term degradation upon contact with patient body fluids; said surface coating comprising a membrane having the enzyme cross linked with a serum protein which includes albumin and bonded to said tubular element, and wherein said at least one enzyme comprises phospholipase.
Claim 2
Dependent Claim
115 words
A catheter, comprising: an elongated tubular element formed from a polymeric material and adapted for patient placement, said tubular element defining a catheter lumen; and a surface coating applied to said tubular element on at least a portion of the surface thereof, said surface coating including at least one enzyme effective to dissolve occlusions along said catheter lumen, said at least one enzyme comprising a lipolytic enzyme, and means for protecting said enzyme against short-term degradation upon contact with patient body fluids; said surface coating comprising a membrane having the enzyme cross linked with a serum protein which includes albumin and bonded to said tubular element, and wherein said at least one enzyme comprises phospholipase.
Claim 3
Dependent Claim
19 words
The catheter of claim 1 wherein said at least one enzyme comprises a combination of fibrinolytic and lipolytic enzymes.
Claim 4
Dependent Claim
30 words
The catheter of claim 1 wherein the enzyme is cross linked with the serum protein by an aldehyde, and further including means for bonding the aldehyde to said tubular element.
Claim 5
Dependent Claim
60 words
A catheter, comprising: an elongated tubular element formed from a polymeric material and adapted for patient placement, said tubular element defining a catheter lumen; and at least one enzyme on at least a portion of the surface of said tubular element, said enzyme being effective in the presence of patient body fluids to dissolve lipid-based occlusions along said catheter lumen.
Claim 6
Dependent Claim
60 words
A catheter, comprising: an elongated tubular element formed from a polymeric material and adapted for patient placement, said tubular element defining a catheter lumen; and at least one enzyme on at least a portion of the surface of said tubular element, said enzyme being effective in the presence of patient body fluids to dissolve lipid-based occlusions along said catheter lumen.
Claim 7
Dependent Claim
20 words
The catheter of claim 4 further including means for protecting said enzyme against short-term degradation upon contact with patient fluids.
Claim 8
Dependent Claim
13 words
The catheter of claim 4 wherein said at least one enzyme comprises phospholipase.
Claim 9
Independent Claim
59 words
A method of applying an enzyme coating to a polymeric catheter, said method comprising the steps of: cross link bonding at least one lipolytic enzyme which includes phospholipase with a serum protein which includes albumin by means of a cross link agent; and bonding the cross link agent to at least a portion of the surface of the catheter.
Claim 10
Independent Claim
59 words
A method of applying an enzyme coating to a polymeric catheter, said method comprising the steps of: cross link bonding at least one lipolytic enzyme which includes phospholipase with a serum protein which includes albumin by means of a cross link agent; and bonding the cross link agent to at least a portion of the surface of the catheter.
Claim 11
Dependent Claim
13 words
The method of claim 7 wherein the cross link agent is an aldehyde.
Claim 12
Dependent Claim
30 words
The method of claim 7 wherein said cross link bonding step comprises forming a slurry of the enzyme and serum protein, and contacting the slurry with the cross link agent.
Claim 13
Dependent Claim
32 words
The method of claim 7 wherein said step of bonding the cross link agent to the catheter comprises bonding the cross link agent to the catheter by means of a silane compound.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-09 | 1999-10-09 | 2000-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-09 | 2003-10-09 | 2004-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-09 | 2007-10-09 | 2008-04-09 | $7700.00 | Window Closed / Lapsed |