Search

EP-4735545-A2 - COATED EPTFE LINERS FOR CATHETERS

EP4735545A2EP 4735545 A2EP4735545 A2EP 4735545A2EP-4735545-A2

Abstract

Expanded polytetrafluoroethylene (ePTFE) tubings are provided with a thermoplastic tie layer coating on the outer surface thereof to serve, e.g., as flexible liners for catheters. The thermoplastic tie layer coating can be anchored into the pores of the ePTFE but advantageously does not permeate through to the inner surface of the tubing. In this way, the outer surface of the tubing can adhere to an outer jacket material while the inner surface of the tubing remains lubricious.

Inventors

  • YOUNAN, ALEXANDRA NIJELA
  • CAMPANELLI, JOHN RICHARD

Assignees

  • Zeus Company LLC

Dates

Publication Date
20260506
Application Date
20240626

Claims (20)

  1. 1. A coated tubing, comprising: an expanded polytetrafluoroethylene (ePTFE) tubing with an inner surface and an outer surface and a wall with a thickness; and a thermoplastic tie layer coating on at least a portion of the outer surface.
  2. 2. The coated tubing of claim 1 , wherein the thermoplastic tie layer coating is on substantially all of the outer surface.
  3. 3. The coated tubing of claim 1 or 2, wherein the thermoplastic tie layer coating permeates from the outer surface through the wall of the ePTFE tubing to a depth of 80% or less of the wall thickness.
  4. 4. The coated tubing of claim 3, wherein the thermoplastic tie layer permeates from the outer surface through the wall of the ePTFE tubing to a depth of 60% or less of the wall thickness.
  5. 5. The coated tubing of claim 4, wherein the thermoplastic tie layer permeates from the outer surface through the wall of the ePTFE tubing to a depth of 50% or less of the wall thickness.
  6. 6. The coated tubing of any of claims 1-5, wherein the inner surface comprises no thermoplastic tie layer coating.
  7. 7. The coated tubing of any of claims 1-6, wherein the thermoplastic tie layer coating has an average coating thickness from the outer surface outwards of 1 pm or greater.
  8. 8. The coated tubing of any of claims 1-7, wherein the thermoplastic tie layer coating has a durometer hardness between 93A and 55D.
  9. 9. The coated tubing of any of claims 1-8, wherein the thermoplastic tie layer coating comprises or consists essentially of one or more of a polyether block amide, a polyurethane, a nylon, or a derivative or copolymer thereof.
  10. 10. The coated tubing of any of claims 1-9, wherein the tie layer coating is non-uniformly distributed throughout the wall thickness.
  11. 11. The coated tubing of any of claims 1-10, wherein the ePTFE tubing has an inner diameter of 0.6 mm or greater.
  12. 12. The coated tubing of any of claims 1-11, wherein the ePTFE tubing has an average wall thickness of 0.03 mm or greater, 0.04 mm or greater, or 0.05 mm or greater, e.g., 0.03 to 0.1 mm.
  13. 13. The coated tubing of any of claims 1-12, wherein the ePTFE tubing has an intemodal distance (IND) of greater than 5 gm.
  14. 14. A catheter comprising the coated tubing of any of claims 1-13, configured such that the catheter has a catheter inner surface corresponding to the inner surface of the ePTFE tubing.
  15. 15. The catheter of claim 14, further comprising a reinforcing layer on an outer surface of the coated tubing (e.g., a braided or coiled wire).
  16. 16. The catheter of claim 14 or 15, further comprising a catheter jacket.
  17. 17. A catheter assembly comprising: an expanded polytetrafluoroethylene (ePTFE) liner with an inner surface and an outer surface and a wall thickness; and a thermoplastic tie layer coating with an average coating thickness of 1 pm or greater and a durometer hardness between 93 A and 55D disposed on the outer surface of the ePTFE liner to give a coated liner, wherein the ePTFE liner has a bonding affinity to the thermoplastic tie layer coating.
  18. 18. The catheter assembly of claim 17, wherein the thermoplastic tie layer coating is on substantially all of the outer surface.
  19. 19. The catheter assembly of claim 17 or 18, wherein the thermoplastic tie layer coating permeates into the wall from the outer surface through the wall of the ePTFE tubing to a depth of less than the wall thickness.
  20. 20. The catheter assembly of claim 19, wherein the thermoplastic tie layer coating permeates into the wall to a depth of 80% or less of the wall thickness, 60% or less of the wall thickness, or 50% or less of the wall thickness.

Description

COATED EPTFE LINERS FOR CATHETERS FIELD OF THE DISCLOSURE The present disclosure relates to tubings comprising tie layer coatings thereon, which tubings can serve as components of catheter assemblies. BACKGROUND Polytetrafluoroethylene (PTFE) has been an ideal material for inner liners of catheters due to the chemical resistance, biocompatibility, and low coefficient of friction (COF) of PTFE. PTFE exhibits unique characteristics in this field that other polymers do not exceed. With such a low COF, PTFE has been able to provide an inner diameter (ID) that easily allows various catheter technologies such as stents, balloons, atherectomy or thrombectomy devices to be pushed through a small diameter catheter lumen. The effect of high lubricity of the catheter ID is a reduced deployment force of catheter devices as the catheter devices are passed through the lumen of the catheter ID, increasing the likelihood of a successful procedure. In catheter constructions, the catheter liner is stretched over a mandrel, which usually comprises stainless steel or PTFE. A braided or coiled wire reinforcing layer may be constructed on top of the liner and can vary in picks, wire dimensions, and materials for different applications. A catheter jacket is then slid over the underlying layers, followed by a heat shrink tube over the catheter jacket. A thermoplastic tie layer made typically of the same material and durometer as the catheter jacket can be deposited on the surface of the catheter liner for enhanced adhesion. The finalized construction is then laminated together and removed from the mandrel, resulting in a fully built catheter. As minimally invasive surgical procedures using catheters extend further into the vasculature, such as above the neck or below the knee applications, catheters must navigate smaller vessels and sharper turns. In neurovascular procedures to treat ischemic strokes, catheters are required to deliver therapies in a safe and effective manner through tortuous blood vessels. These catheter liners are thus required to be highly flexible in addition to being highly lubricious. Thus, development of catheter liners capable of providing both surface lubricity and flexibility would be desirable in the art. SUMMARY A catheter liner is provided based on an ePTFE tubing with a thermoplastic tie layer coated on at least a portion of an outer surface thereof. The liner is a thin-walled ePTFE tubing that advantageously has a relatively open node and fibril structure, and therefore a relatively large intemodal distance (IND), to allow the tie layer material to better adhere to the outer surface of the ePTFE tubing. The thermoplastic tie layer coating can comprise or consist essentially of one or more of PEBA, nylon, and/or polyurethane (as well as derivatives and/or copolymers thereof). In some embodiments, the IND of the ePTFE tube is between 5pm and 100pm. In some embodiments, the IND of the ePTFE tube is essentially constant throughout the wall thickness from ID to outer diameter (OD). In some embodiments, the IND of the ePTFE tube is greater on the OD and smaller on the ID. The disclosure further provides methods of preparing coated ePTFE tubings, e.g., coated ePTFE liners. In one non-limiting embodiment, an ePTFE tubing is placed on a mandrel and dipped at an angle into a solution of the thermoplastic. The coated tube is then removed from the solution and removed from the mandrel and dried, forming the thermoplastic-coated surface of the tubing/catheter liner of the disclosure. The conditions of the dip coating process can, in some embodiments, be altered to create customized coating thickness and properties of the ePTFE-based catheter liner. In some embodiments, the thermoplastic tie layer coating thickness is between 1 pm and 100 pm. In some embodiments the coated ePTFE tubing is prepared using a thermoplastic solution comprising 5% PEBA 55D in n-butanol. In some embodiments, the thermoplastic solution is 5% PEBA 25D in n-butanol. In some embodiments, the thermoplastic solution is 5% TECOFLEX® 93A polyurethane in n-butanol. In some embodiments, the thermoplastic solution is 3% TECOFLEX® 93A polyurethane in n-butanol. In some embodiments, the thermoplastic solution is 8% TECOTHANE® polyurethane in tetrahydrofuran. In some embodiments, the solution is at room temperature. In some embodiments, the solution is heated up to 10°C below the solvent boiling point. In some embodiments, the durometer hardness of the thermoplastic resin used to prepare the disclosed coated ePTFE tubings as tested according to ASTM D2240 is between 93A and 55D. In some embodiments, the coated tube is dried in air at room temperature. In some embodiments, the coated tube is dried at elevated temperature, such as in a circulating air oven at temperatures e.g., as high as the boiling point of the solvent. In some embodiments, the amount of time the ePTFE liner is submerged in the thermoplastic solution is between 10 and 60 seconds. In