Indwelling catheter with stable enzyme coating
First Claim
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1. 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, and means for protecting said enzyme against short-term degradation upon contact with patient body fluids;
said at least one enzyme comprising a substantially micellar array of enzyme particles on said tubular element, and further wherein said enzyme protecting means comprises a porous encapsulant film covering said enzyme particles and adhering securely to said tubular element, said encapsulant film having a controlled porosity to permit diffusion passage of body fluid constituents effective to activate the enzyme for occlusion control while substantially shielding the enzyme against degradation;
said at least one enzyme being selected from the group consisting of urokinase, streptokinase, tissue plasminogen activator (TPA) and phospholipase, and mixtures thereof.
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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.
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Citations
7 Claims
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1. A catheter, comprising:
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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, and means for protecting said enzyme against short-term degradation upon contact with patient body fluids; said at least one enzyme comprising a substantially micellar array of enzyme particles on said tubular element, and further wherein said enzyme protecting means comprises a porous encapsulant film covering said enzyme particles and adhering securely to said tubular element, said encapsulant film having a controlled porosity to permit diffusion passage of body fluid constituents effective to activate the enzyme for occlusion control while substantially shielding the enzyme against degradation; said at least one enzyme being selected from the group consisting of urokinase, streptokinase, tissue plasminogen activator (TPA) and phospholipase, and mixtures thereof. - View Dependent Claims (2)
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3. A method of applying an enzyme coating to a polymeric catheter, said method comprising the steps of:
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applying a selected enzyme to at least a portion of the surface of the catheter in a substantially micellar array, said at least one enzyme being selected from the group consisting of urokinase, streptokinase, tissue plasminogen activator (TPA) and phospholipase, and mixtures thereof; and encapsulating the micellar array of enzyme with a porous encapsulant film covering the enzyme and adhering to the catheter to retain the enzyme against the catheter surface, for activation upon diffusion passage of patient body fluid constituents to dissolve catheter occlusions. - View Dependent Claims (4, 5, 6, 7)
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Specification