Anti-inflammatory cannula

Abstract

Various embodiments of the present invention include a cannula coated or compounded with a material to extend the wear time for a patient by reducing inflammation and therefore increasing the time that the cannula may remain inserted, thereby increasing the effectiveness of the drug delivered using the cannula. The material may include a hydrophilic material, an anti-microbial material, an anti-inflammatory material, anti-thrombogenic material, or a combination of any of these materials.

Description

TECHNICAL FIELD

Embodiments of the present invention relate generally to medication delivery and, more particularly, to systems and methods for long-term cannula usage.

BACKGROUND

A cannula is a thin tube that can be inserted into a patient's vasculature, body cavity or tissue to administer drugs, drain fluids, or insert a surgical instrument. A needle may be used to facilitate the percutaneous delivery of a cannula through the patient's skin so that when placed into its working configuration, the proximal end of the cannula remains outside of the patient's body while the distal end is placed within the intended body lumen, cavity or tissue.

Cannulas may be used for short-term or long-term treatment or therapy. For example, the cannula may remain in place for an extended time period for the long-term delivery of drugs for patients undergoing chemotherapy, for insulin delivery or for the delivery of other fluids via intravenous infusion, drug pumps, a syringe, or the like. Regardless, the use of cannulas may result in inflammation, infection or thrombus formation due to factors such as the presence or introduction of bacteria at the cannula insertion site and unintended blood flow into the cannula. Such inflammation, infection or thrombus formation may cause discomfort or harm to the patient and, in the case of long term drug therapy, may impact therapy effectiveness due to the physiological changes caused by the inflammation at the insertion site.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a first view of a first embodiment of a cannula.

FIG. 1B illustrates a second view of the first embodiment of the cannula.

FIG. 2A illustrates a first view of a second embodiment of a cannula.

FIG. 2B illustrates a second view of the second embodiment of the cannula.

DETAILED DESCRIPTION

Various embodiments of the present invention include a cannula coated or compounded with a material to extend the wear time for a patient by reducing inflammation and increasing the time that the cannula may remain inserted, thereby improving the effectiveness of the drug delivered using the cannula or increasing the effectiveness of the use of the cannula. The material may include a hydrophilic material, an anti-microbial material, an anti-inflammatory material, anti-thrombogenic material, or a combination of any of these materials.

The cannula may be made of any suitable material, including polymeric, metallic and composite materials. In some embodiments, the cannula is made using an elastomeric polymer material such as fluoropolymer, polyurethane, or silicone. In these embodiments, the cannula may be soft and/or flexible. In other embodiments, the cannula is made from a rigid material such as metal or rigid plastic, such as polyvinyl chloride. The cannula may be manufactured by extruding or molding the material into a tube or other shape (or by any other means known in the art).

FIGS. 1A and 1B illustrate axial 100A and longitudinal 100B cross-sectional views, respectively, of a cannula 102 in accordance with embodiments of the present invention. The cannula 102 generally comprises an extended member having an open lumen 106 therein, and terminating at a distal end 108. Although the lumen 106 is illustrated as being circular in cross-sectional shape, any suitable cross-sectional shape may be used in the present invention, including ovular and rectangular. The cannula 102 can be configured to be inserted through a patient's skin by delivery with a needle or the like, such that the distal end 108 is implanted into the intended vasculature, tissue or body cavity.

In various embodiments, the cannula 102 can include a first material, such as a polymer or metal, and can be coated with a coating 104. As shown in FIGS. 1A and 1B, the coating 104 can at least partially coat the outer or exterior surface 102a of cannula 102. In other embodiments, the coating 104 can at least partially coat the inner surface 102b of the cannula 102, in addition to or instead of coating the exterior surface 102a of cannula 102.

The coating 104 can include a second material that may be a hydrophilic material, an anti-microbial material, an anti-inflammatory material, an anti-thrombogenic material, or any combination thereof. Examples of coating material types include polymers that provide desired surface characteristics, polymers that include drugs admixed therein, drugs that can be directly applied to the cannula 102 without the need for a polymer, metal-polymer combinations, and metallic materials. Such materials include, for example, heparin, silver and its alloys, rifampicin, sparfloxacin, triclosan, benalkonium chloride, tridodecylmethylammonium chloride, cefazolin, chitosan, dexamethasone sodium phosphate, polyvinylpyrolidone (PVP), polyurethanes, fluoropolymers, silicone, polyacrylic acid (PAA), polyethylene oxide (PEO), polysaccharides, fluorine-acryl-styrene-urethane-silicone (FASUS), and other suitable materials. In various embodiments, the coating 104 can comprise polyurethane and/or fluorinated ethylene propylene. In various other embodiments, the coating 104 comprises fluorinated ethylene propylene or fluorinated ethylene-propylene copolymer applied to the inner surface 102b of cannula 102 and a polyether block amide applied to the exterior surface 102a of cannula 102.

The coating 104 may be deposited on either or both of the exterior surface 102a and inner surface 102b of the cannula 102 by vapor deposition, liquid application, dip coating, spray coating or any other suitable means. In other embodiments, the coating 104 can be manufactured together with the cannula 102 during a co-extrusion process. If the coating 104 includes more than one of the hydrophilic material, anti-microbial material, and/or anti-inflammatory material, these components may be mixed homogenously, disposed in discrete layers or regions of the coating 104, or be disposed in concentration gradients throughout the coating 104. In certain embodiments, the coating 104 can include multiple layers of the same or different materials.

The thickness of the coating 104 can depend upon the specific clinical application and the material used in the coating. As non-limiting examples, the coating 104 can be formed up to 500 microns in thickness, preferably up to 100 microns, and more preferably up to 50 microns. In some embodiments, the coating 104 can be applied along the entire length of either or both of the inner and exterior surfaces of cannula 102, while in other embodiments, the coating 104 can be applied along only a portion of the length of the cannula 102 (e.g., a distal segment of the cannula 102 terminating at the distal end 108). It should also be appreciated that the coating 104 may be applied to the entire perimeter of either or both of the inner and exterior surfaces of cannula 102, or to only a portion of the perimeter.

In various embodiments, the coating 104 can be applied to the exterior surface 102a of a cannula 102 that is part of a wearable drug-delivery pump, such as an OmniPod® (Insulet Corporation, Billerica, Mass., USA). Aspects of such pumps may be described in U.S. Pat. Nos. 7,030,549; 7,144,384; 7,137,964; 6,960,192; 6,740,059; 6,699,218 and 6,656,159, each of which is incorporated herein by reference. In various embodiments, as shown and described in the aforementioned referenced U.S. patents, a cannula (e.g., the cannula 102 can extend from an insulin pump that is adhered to the patient's skin with an adhesive material located on a pump housing. Insulin is delivered at programmed infusion rates over prolonged time periods (e.g., five to seven days) from a chamber within the housing that holds the insulin in the pump through the cannula 102 that extends from the pump and through the patient's skin. In this embodiment, the cannula 102 is at least partially coated on its exterior surface 102a with a coating 104 that comprises an anti-inflammatory agent. The cannula 102 is in fluid connection to the chamber, and the distal end of the cannula 102 extends into the patient (see, e.g., U.S. Pat. No. 7,137,964, FIGS. 1-6, col. 5, line 53 col. 11, line 62).

FIGS. 2A and 2B illustrate axial 200A and longitudinal 200B cross-sectional views, respectively, of a cannula 202 in accordance with other embodiments of the present invention. In these embodiments, the cannula 202 can be made of a first material, and a second material can be mixed/compounded with the first material. The second material can be the hydrophilic material, anti-microbial material, anti-inflammatory material and/or anti-thombogenic material, or a combination thereof, as described for embodiments with coating 104. As illustrated, the second material may be disposed in relatively large, discrete regions 204 in the cannula 202. In other embodiments, however, the second material can be disposed in smaller regions in the cannula 202. Any degree of mixing/compounding is within the scope of the present invention, including homogeneous dispersions and preferential placement within cannula 202.

Overall, various embodiments provide a cannula that can be made of one or more materials. The cannula can include a coating positioned over all or a portion of an outer and/or inner surface of the cannula. The coating can be made from one or more materials. The same coating can be applied to the inner or outer surface or different coatings can be applied to the inner and outer surfaces of the cannula. One or more materials can be used as a coasting for either the inner or the outer surfaces. For example, a first portion of the cannula can be coasted with a first material and a second portion of the cannula can be coated with a second material. The first and second portions can overlap. Any of the materials described herein can be used for the coating or covering for the cannula (or otherwise applied to a surface of the cannula). Any of the materials described herein can be used to form the cannula body. In various other embodiments, the cannula can be formed from two or more materials with one of the materials comprising a hydrophilic material, an anti-microbial material, an anti-inflammatory material and/or an anti-thombogenic material, or any combination thereof. For example, a first material can be impregnated or combined with one or more second materials to form the cannula, with the second materials selected from a hydrophilic material, an anti-microbial material, an anti-inflammatory material and/or an anti-thombogenic material, or any combination thereof. One or more coatings of one or more different materials can then be further applied to any surface of such a cannula.

Claims

1. A wearable fluid delivery device, comprising: a chamber containing a fluid to be delivered into a body of a patient; anda cannula in fluid connection with the chamber, the cannula comprising an exterior surface, an inner surface, a lumen and a distal end extending into the patient, wherein the cannula comprises a first material and a second material mixed with the first material, the second material disposed in discrete regions of the cannula, the second material comprising at least one of a hydrophilic material, an anti-microbial material, an anti-inflammatory material, and an anti-thombogenic material, wherein a first coating at least partially covers the exterior surface of the cannula, the first coating comprising an anti-inflammatory agent, wherein a second coating at least partially covers the interior surface of the cannula, the second coating comprising at least one of the hydrophilic material, the anti-microbial material, the anti-inflammatory material, and the anti-thombogenic material,wherein the second coating covers less than an entire length of the inner surface of the cannula,wherein the first coating covers less than an entire length of the exterior surface of the cannula,wherein the second coating coats less than an entire perimeter of the inner surface of the cannula,wherein the first coating coats less than an entire perimeter of the exterior surface of the cannula,wherein a third coating at least partially covers the exterior surface of the cannula, the third coating comprising at least one of the hydrophilic material, the anti-microbial material, the anti-inflammatory material, and the anti-thombogenic material, wherein the first and second coatings comprise different materials,wherein the third coating is disposed in a concentration gradient throughout the first coating.

2. The wearable fluid delivery device of claim 1, wherein the first material of the cannula comprises a polymeric material.

3. The wearable fluid delivery device of claim 1, the first coating having a thickness of up to 500 microns.

4. The wearable fluid delivery device of claim 1, the first coating having a thickness of up to 50 microns.

5. The wearable fluid delivery device of claim 1, wherein the first coating comprises a material selected from the group consisting of heparin, silver and its alloys, rifampicin, sparfloxacin, triclosan, benalkonium chloride, tridodecylmethylammonium chloride, cefazolin, chitosan, dexamethasone sodium phosphate, polyvinylpyrolidone (PVP), polyurethanes, fluoropolymers, silicone, polyacrylic acid (PAA), polyethylene oxide (PEO), polysaccharides, polyether block amides, and fluorine-acryl-styrene-urethane-silicone (FASUS).

6. The wearable fluid delivery device of claim 5, wherein the first material of the cannula comprises polyurethane.

7. The wearable fluid delivery device of claim 5, wherein the first coating comprises a polyether block amide.

8. The wearable fluid delivery device of claim 1, wherein said second coating comprises an anti-thrombogenic material.

9. The wearable fluid delivery device of claim 8, wherein said second coating comprises a fluorinated ethylene propylene.

10. The wearable fluid delivery device of claim 1, wherein the cannula comprises a single unitary body.

11. The wearable fluid delivery device of claim 1, wherein a fourth coating at least partially covers the inner surface of the cannula, the fourth coating comprising at least one of a hydrophilic material, an anti-microbial material, an anti-inflammatory material, and an anti-thombogenic material, the second and fourth coatings comprising different materials.

12. The wearable fluid delivery device of claim 11, wherein the second and fourth coatings are mixed homogeneously.

13. The wearable fluid delivery device of claim 11, wherein the fourth coating is disposed in discrete regions of the second coating.

14. The wearable fluid delivery device of claim 11, wherein the second and fourth coatings overlap.

15. The wearable fluid delivery device of claim 11, wherein the second and fourth coatings are non-overlapping.

16. The wearable fluid delivery device of claim 11, wherein the fourth coating is disposed in a concentration gradient throughout the second coating.

17. The wearable fluid delivery device of claim 1, wherein the cannula comprises a third material mixed with the first material, the third material disposed in discrete regions of the cannula, the third material comprising at least one of the hydrophilic material, the anti-microbial material, the anti-inflammatory material, and the anti-thombogenic material, wherein the first, second, and third materials of the cannula each comprise different materials.