Stent insert for treatment of mastitis

Abstract

A stent insert for retention in a mammary gland of a livestock animal, the stent insert having a stent body having shape memory having an expanded condition and collapsed condition, the stent body having a first material being at least partially elastic. The stent insert also has one or more nodes attached to the stent body, the nodes have a second material, the second material being a bioactive material for releasing at the mammary gland to prevent mastitis.

Description

[0001] STENT INSERT FOR TREATMENT OF MASTITIS

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a stent insert for cattle or other livestock animals. More particularly, but not exclusively, it relates to a stent insert and method of preventing mastitis in cattle or other livestock animals.

[0004] BACKGROUND OF THE INVENTION

[0005] For farmers keeping livestock, the health of the animals is a key concern. Mastitis issues, being the inflammation of the mammary gland of an animal, is one of the most common health problems for cattle. Mastitis is most commonly caused by bacteria such as mycoplasma bovis invading the udder, although many other types of bacteria can also be responsible. It can be classified into clinical mastitis, where there are visible signs of inflammation, and subclinical mastitis, where there are no visible symptoms and detection is difficult. Mastitis of either type reduces yield and quality of milk, due to mammary tissue damage. Although clinical mastitis can at least be visually identified and treated, some estimates indicate that on average, around 25% of animals in every dairy herd are infected with subclinical mastitis continuously. Mastitis therefore has a direct effect on profitability of the dairy industry as it decreases volumes of milk production. Where mastitis affects the same animal multiple times, the animal may no longer be useful for milk production.

[0006] Because of the considerable expense of identifying and treating such issues, preventative solutions that can be administered en masse may be desirable. Typically, antibiotics are widely used for this purpose. To prevent mastitis, antibiotics may be used in conjunction with teat sealants, typically applied by syringe. However, these syringes are typically single-dose, which creates high volumes of plastic waste at scale.

[0007] Furthermore, a major problem with the widespread use of antibiotics as disease preventatives in livestock is that it accelerates the development of antibiotic resistance in the targeted bacterial strains. This is gradually rendering common antibiotics ineffective, which will eventually leave farmers to contend with failing livestock health and no cost- effective and useful preventative medicine available. This problem is now beginning to impact the industry significantly, making it increasingly desirable to find alternative solutions for preventing and / or treating mastitis.

[0008] Cattle typically progress through the different stages of lactation, including early lactation, mid-lactation, late lactation and a dry period. Typically, solutions to reduce mastitis are provided during the dry period (e.g. teat sealants) as bacterial and other microorganisms are more likely to enter the mammary gland and multiply during this period. However, application and removal of these products can be a labour intensive and costly task to perform each year. Therefore, an alternative solution for preventing and / or treating mastitis may be desirable.

[0009] In this specification, where reference has been made to external sources of information, including patent specifications and other documents, this is generally for the purpose of providing a context for discussing the features of the present invention. Unless stated otherwise, reference to such sources of information is not to be construed, in any jurisdiction, as an admission that such sources of information are prior art or form part of the common general knowledge in the art.

[0010] For the purpose of this specification, where method steps are described in sequence, the sequence does not necessarily mean that the steps are to be chronologically ordered in that sequence, unless there is no other logical manner of interpreting the sequence.

[0011] It is an object of the present invention to provide a stent insert and method of treating mastitis which overcomes or at least partially ameliorates some of the abovementioned disadvantages or which at least provides the public with a useful choice.

[0012] BRIEF DESCRIPTION OF THE INVENTION

[0013] According to a first aspect the invention broadly comprises a stent insert for retention in a mammary gland of a livestock animal, the stent insert comprising: a stent body having shape memory having an expanded condition and collapsed condition, the stent body comprising a first material being at least partially elastic, wherein the stent body is elongate having a longitudinal axis; one or more nodes attached to the stent body, the nodes comprising a second material, the second material being a bioactive material for releasing at the mammary gland to prevent mastitis.

[0014] According to another aspect the stent insert is a dual material component where the first material of the stent body and second material of the one or more nodes are different.

[0015] According to another aspect the one or more nodes are flat and in line with an outer wall and the longitudinal axis of the stent body.

[0016] According to another aspect each of the one or more nodes comprises between 10 to 100 micrograms of bioactive material.

[0017] According to another aspect the one or more nodes are circular.

[0018] According to another aspect the stent insert comprises a plurality of nodes.

[0019] According to another aspect the stent insert comprises four or more nodes.

[0020] According to another aspect the stent insert comprises twelve nodes.

[0021] According to another aspect the nodes are located at both ends of the stent body.

[0022] According to another aspect the one or more nodes are located at one end of the stent body.

[0023] According to another aspect the stent insert further comprises a bioactive coating.

[0024] According to another aspect the bioactive coating has a thickness of less than 3 microns.

[0025] According to another aspect wherein the bioactive coating has as thickness of approximately 1 micron.

[0026] According to another aspect the bioactive material of the nodes is the same as the bioactive coating. According to another aspect the bioactive material is an antimicrobial.

[0027] According to another aspect the bioactive material is one or a combination of copper, zinc, silver, and / or cobalt.

[0028] According to another aspect the first material is one or a combination of nitinol, titanium, and / or chromium.

[0029] According to another aspect the stent body comprises filaments to form an interwoven mesh.

[0030] According to another aspect the stent body comprises a single filament.

[0031] According to another aspect the shape memory of the stent body allows for cyclical contraction and expansion of the stent body to accommodate pulsation of the mammary gland.

[0032] According to another aspect the stent body is rated to endure at least 100 million pulsation cycles.

[0033] According to another aspect the stent insert in the expanded condition has a length of between 5 to 60 mm.

[0034] According to another aspect the stent insert in the expanded condition has a diameter of between 2 to 30 mm.

[0035] According to another aspect the stent insert collapses to less than a fifth of its expanded diameter upon moving to the collapsed condition.

[0036] According to another aspect the stent insert comprises a first open end, a second open end and an unobstructed passage along the longitudinal axis of the stent body from the first open end to the second open end.

[0037] According to another aspect the stent insert is configured such that a milk may flow through the unobstructed passage from the first open end to the second open end. According to another aspect the invention broadly comprises a method of preventing mastitis in a livestock animal, the method comprising: providing a stent insert, the stent insert comprising a stent body having a shape memory, having an expanded condition and a collapsed condition, and being at least partially elastic, wherein the stent body is coated with and / or comprises nodes of a bioactive material for releasing at the mammary gland to prevent mastitis; inserting the stent insert into a mammary gland of the animal; releasing the stent insert in the mammary gland of the animal in the expanded condition; leaving the stent insert in the mammary gland of the animal; the stent insert releasing the bioactive material at the mammary gland to prevent mastitis.

[0038] According to another aspect the method further comprises leaving the stent insert in the mammary gland during lactation of the animal.

[0039] According to another aspect the method further comprises leaving the stent insert in the mammary gland during both lactation and dry periods of the animal.

[0040] According to another aspect the method further comprises leaving the stent insert in the mammary gland of the animal permanently.

[0041] According to another aspect the stent insert is inserted in the collapsed condition.

[0042] According to another aspect the method further comprises guiding the stent insert into the mammary gland of the animal using an introductory tool.

[0043] According to another aspect the stent insert is provided with a hydrophobic covering which is removed or retracted by the introductory tool as the stent insert is released. According to another aspect the stent insert is inserted through or into teat canal of the animal.

[0044] According to another aspect the stent insert is inserted into the animal by incision.

[0045] According to another aspect the stent insert is inserted into the gland cistern of the animal.

[0046] According to another aspect the stent insert is inserted into the teat cistern of the animal. According to another aspect the animal is non-human.

[0047] According to another aspect the animal is cattle for milking.

[0048] According to another aspect the stent insert comprises a first open end, a second open end and an unobstructed passage along the longitudinal axis of the stent body from the first open end to the second open end.

[0049] According to another aspect the method further comprises milking the cow, wherein milk flows through the unobstructed passage.

[0050] According to another aspect the invention broadly comprises a method of manufacturing the stent insert, the method comprising: forming the stent body; and attaching the nodes to the stent body.

[0051] According to another aspect attaching the nodes is achieved by marker pressing, stamping, fusing, or hydraulic pressing.

[0052] According to another aspect the method further comprises applying a bioactive coating to the stent insert.

[0053] According to another aspect applying the bioactive coating onto the stent insert is a physical vapor deposition (PVD) process. According to another aspect applying the bioactive coating onto the stent is a chemical vapor deposition (CVD) process.

[0054] According to another aspect forming the stent body is achieved by laser cutting from a tube of the first material.

[0055] According to another aspect forming the stent body is achieved by knitting or braiding the first material.

[0056] Other aspects of the invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings.

[0057] As used herein the term "and / or" means "and" or "or", or both.

[0058] As used herein "(s)" following a noun means the plural and / or singular forms of the noun.

[0059] The term "comprising" as used in this specification and claims means "consisting at least in part of". When interpreting statements in this specification and claims which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as "comprise" and "comprised" are to be interpreted in the same manner.

[0060] BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The invention will now be described by way of example only and with reference to the drawings in which:

[0062] Figure 1 shows a perspective view of a stent insert.

[0063] Figure 2 shows an end view of the stent insert.

[0064] Figure 3 shows a side view of the stent insert.

[0065] Figure 4 shows a close-up view of the stent insert with nodes.

[0066] Figure 5 shows a configuration of nodes on the stent insert.

[0067] Figure 6 shows another configuration of nodes on the stent insert.

[0068] Figure 7 shows yet another configuration of nodes on the stent insert.

[0069] Figure 8 shows a stent insert in a collapsed condition being inserted into a gland cistern. Figure 9 shows a stent insert in an expanded condition being released in the gland cistern.

[0070] Figure 10 shows a stent insert in a collapsed condition being inserted into a teat cistern.

[0071] Figure 11 shows a stent insert in an expanded condition being released in the teat cistern.

[0072] Figure 12 shows a coating process for coating the stent insert with a bioactive material.

[0073] Figure 13 shows a perspective view of an alternative stent insert without nodes.

[0074] Figure 14 shows a perspective view of an alternative stent insert without nodes, comprising a single filament.

[0075] Figure 15 shows a side view of an alternative stent insert with a tapered end.

[0076] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0077] According to various aspects of the present invention as illustrated in figures 1 -12, there is provided a stent insert 1 for retention in a mammary gland of a livestock animal and method of preventing mastitis in a livestock animal which will now be described.

[0078] It will be appreciated that these figures illustrate the general principles of the structure and construction, and that the invention is not limited to the precise configurations illustrated.

[0079] Function of Stent

[0080] With reference to figure 1, a stent insert 1 is provided for retention in a mammary gland of a livestock animal. The stent insert 1 is configured to be introduced and remain in a livestock animal to prevent or at least reduce the likelihood and / or severity of mastitis.

[0081] Mastitis, being an inflammation of the mammary gland, is caused by the presence of bacteria in the mammary gland. The stent insert 1 is configured to release bioactive material to provide an environment that bacteria would find difficult to survive in, and therefore prevent mastitis.

[0082] Bioactive materials can act on bacteria through physical or chemical action and may exhibit 'contact killing', for example by forming bonds with bacterial cells and damaging them. Release of bioactive material may be in the form of biocidal ion release. Use of stent insert 1 and the bioactive material it releases can be advantageous over typical antibiotics in preventing mastitis, because antibiotics may have more subtle working mechanisms that bacteria tend to develop resistance to over time.

[0083] The stent insert 1 is adapted to be usable during the lactation period of the livestock animal, and hence to be retained in the mammary gland even during milking. The stent insert 1 is adapted to allow milk to flow through it by having open ends and an unobstructed passage between those open ends. Milking involves an inherent risk of having foreign bacteria enter the mammary gland and causing mastitis infection, so the stent insert 1 can mitigate this risk if it is placed in advance.

[0084] The features of the stent insert 1 , which will be described in more detail, allow it to withstand pulsations of the mammary gland that are typical during lactation, remain in place after installation without the need for frequent replacement or adjustment, and to avoid contaminating milk that it comes into contact with.

[0085] The stent insert 1 can improve the average milk yield, milk quality, and hence the profitability of livestock animals during the lactation period by continuously preventing bacterial infection. Benefits may be even greater than would be expected from simply preventing a typical number of clinical mastitis cases in a herd, because subclinical mastitis cases or other bacterial infections that cause degraded milk yield / q ua lity can be prevented when they may have otherwise gone untreated due to a lack of visible symptoms.

[0086] Key Concept 1: Shape Memory, Elastic Material of Stent

[0087] In some configurations, as shown in figure 1 , the stent insert 1 comprises a stent body 10 having shape memory. The shape memory of the stent is provided by the stent body 10 being formed from a first material being at least partially elastic. Further, the shape memory is provided by the stent structure, where the stent body 10 comprises filaments to form an interwoven mesh.

[0088] The interwoven mesh could be formed in many different ways, for example figure 13 shows a configuration with an alternative mesh structure. In alternative configurations, the shape memory may be provided by stent body 10 comprising a single filament formed from a first material being at least partially elastic. For example, figure 14 shows a configuration with a single filament structure.

[0089] The stent body 10 is sufficiently elastic to have an expanded condition and collapsed condition. When pressure is applied to the stent body 10, the stent body moves to its collapsed condition. In the collapsed condition the overall size of the stent body insert 1 is smaller which is useful for safe insertion into the animal (especially through narrow passages such as the through a teat canal).

[0090] When pressure is removed from the stent body 10, the stent body moves (back) to its expanded condition. In the expanded condition the stent body 10 is in its intended default form for retention in the mammary gland (e.g. teat or gland cistern in the mammary gland). In the expanded condition the stent insert 1 can be lodged in the intended location within the animal, allow bodily fluids (e.g. milk) to pass through the stent, and / or release the bioactive material into the animal as intended.

[0091] The size and dimension of the stent insert 1 is configured to allow for safe introduction into the animal through the teat canal and also retention within the desired cistern (i.e. teat or gland cistern) within the mammary gland.

[0092] After introduction of the stent insert 1 into the animal and movement to the expanded condition, the shape memory of the stent body 10 allows for cyclical contraction and expansion of the stent body 10 to accommodate for pulsations of the mammary gland. Such pulsations occur naturally during milking, and the shape memory can thereby prevent internal injury to the animal as well as ensuring retention within the cistern. Preferably the stent insert 1 is rated for at least 100 million pulsation cycles.

[0093] In some configurations, the stent body 10 is elongate having a longitudinal axis. In some configurations, the stent insert 1 in the expanded condition has a length of between 5 to 60 mm and a diameter of between 2 to 30 mm.

[0094] Preferably, movement of the stent insert 1 to the collapsed condition primarily involves a reduction in diameter to facilitate insertion longitudinally. Preferably the stent insert 1 collapses to less than one fifth of its expanded diameter, more preferably even further. For example, the diameter may collapse down from 20 mm expanded to 1.5 mm collapsed. The length of the stent insert 1 may actually increase slightly when moving to the collapsed condition, although alternatively the stent insert 1 could be configured to collapse in both length and diameter.

[0095] It should be appreciated the size of the stent insert 1 can allow for safe and painless insertion of the stent insert into the animal, while allowing for retention within the mammary gland of the animal and providing sufficient material for significant bioactive material release to prevent mastitis. Thus, the dimensions and the degree of collapse should be selected as suitable for the target animal.

[0096] In some configurations, the stent body 10 comprises the first material being one or a combination of nitinol, titanium, and / or chromium, which can result in suitable elastic properties and endurance of over 100 million pulsation cycles as desired. It should be appreciated that other material having the desired elastic and semi-rigid properties known to a person skilled in the art may be used to form the stent body 10.

[0097] In some configurations, the stent body 10 is formed from a nitinol-based alloy having shape memory (for example Nickel Titanium NiTi). The nitinol-based superplastic can provide structural integrity and flexibility for the intended use of the stent insert 1. Further the material of the stent body 10 is rust resistant which is suitable in the wet conditions which the stent insert 1 is intended for (within the mammary gland.)

[0098] The stent body 10 may be manufactured by laser cutting from a tube of the first material (e.g. nitinol tube), or by a knitting / braiding process.

[0099] In some configurations, the stent body 10 is intended to be left within the mammary gland for long periods of time. In some configurations, the stent body 10 is intended to be left within the mammary gland permanently.

[0100] The elastic properties of the stent body 10 allow it to resist distortion such as during pulsation of the mammary gland and / or contract with the pulsations and can keep the stent insert 1 in place once inserted. The stent body 10 moves between its expanded and collapsed conditions as the mammary gland pulsates. The stent body 10 returns to its original expanded condition between pulsations. This may be possible despite the millions of cycles of pulsation within the mammary gland the stent is intended to experience. In particular, pulsations are particularly frequent during the lactation period. The material and geometry of the stent insert 1 allows for this. In contrast, products (such as teat sealants) which are intended to be inserted during the dry period only are typically not designed to endure and operate through the lactation period.

[0101] The material of the stent body 10 is semi-rigid and elastic to allow it to collapse and expand for insertion into the animal and then retention in the location of action (cistern in mammary gland). The material should also be non-biodegradable and non-toxic as the stent insert 1 is intended for long-term use within the animal.

[0102] In some configurations, the stent insert 1 may have an opening at each end. In other words, it may have a first open end and a second open end. The stent insert 1 further comprises an unobstructed passage through the stent insert 1 between the first open end and the second open end. The unobstructed passage may allow milk to flow through the stent insert 1.

[0103] With reference to figure 15, in some configurations the stent body 10 may tapered at one or both of the first open end and second open end. In such a configuration, the diameter of the stent body 10 at its open ends would be smaller than the diameter of the stent body 10 at its centre. The tapered ends of the stent body 10 can increase the ease and safety of inserting of the stent insert 1 into the animal.

[0104] Key Concept 2: Bioactive Material

[0105] The stent insert 1 is a bioactive stent insert comprising a bioactive material to be released in the mammary gland to prevent and / or treat conditions and illnesses stemming from the mammary gland of an animal, such as mastitis. It should be understood the stent insert 1 can prevent and / or treat other illnesses or conditions associated with the udder / mammary gland including teat and gland cisterns due to at least bacterial, viral, or fungal issues.

[0106] The stent insert 1 releases bioactive material directly in a targeted location e.g. cistern in the mammary gland. The bioactive material in some configurations is one or a combination of copper, zinc, silver, and / or cobalt (e.g. Cu-Zn, Cu-Zn-Ag). It should be appreciated other material having the desired bioactive properties to create an unsuitable environment for bacterial known to a person skilled in the art may be used. In some configurations, the stent insert 1 is at least partially formed from copper or copper alloy. In some configurations, the bioactive material is an antimicrobial. Particles of the bioactive material released in the target location provides an environment that bacterial will not survive well in. This is a different process to provoking an immune response, which would present under stress conditions. The bioactive material for providing an unsuitable environment for bacteria to proliferate does not rely on the animal's immune response.

[0107] For example, in some configurations, the bioactive material is copper which has a biocidal effect on pathogens including bacteria and viruses. Copper (and other similar materials) can have an antimicrobial effect which prevents bacteria multiplying as well treating and destroying bacteria onsite. Copper can be effective against antibiotic-resistant bacteria.

[0108] Another benefit of using copper is that in moderate concentrations, it is non-toxic to animals. Copper is a metallic mineral which can be processed and eliminated from the body. The copper bioactive sites or regions of the stent insert 1 has a positive biocidal effect on unwanted bacteria, and any released copper ions can be safely excreted from the animal's body.

[0109] It should be appreciated that the bioactive material provided by the stent insert 1 , together with the specific structural form and long-term use within the animal during lactation periods as described in more detail below can be advantageous with the aim of preventing mastitis in cattle. The metallic ions released in the mammary gland can prevent and treat bacterial growth responsible for mastitis.

[0110] Key Concept 3: Bioactive Nodes

[0111] With reference to figure 1 , in some configurations the stent insert 1 comprises one or more nodes 1 1 attached to the stent body 10. The nodes 1 1 comprising a second material, the second material being a bioactive material for releasing at the mammary gland to prevent mastitis. The nodes 11 are attached to the stent body 10 during manufacturing.

[0112] The one or more nodes 1 1 can be attached to the stent 10 by a range of different methods including marker pressing, stamping, fusing, or hydraulic pressing. It should be appreciated other pressing or fusing methods may be used to attach the nodes to the stent body 10. In these configurations, the stent body 10 being formed from a first material being a mesh forming a stent allows it to be inserted safely and retained in the mammary gland over long periods of time as intended. While the nodes 1 1 being formed from a second material releases bioactive material to prevent mastitis. In these configurations, the structural integrity of the stent is not compromised as a durable material can be used for the stent body 10 while the nodes 1 1 have concentrated regions for dispersing the bioactive material. The mesh and hollow nature of the stent insert 1 can allow for the passing of milk, as the stent insert 1 is inserted to be located within the teat or gland cistern.

[0113] In these configurations, the stent insert 1 is a dual material component where the first material of the stent body and second material of the one or more nodes are different.

[0114] In the shown configurations, the stent insert 1 has a specific geometry for safe insertion and retention in the animal, along with supplying adequate bioactive material over a long duration.

[0115] In some configurations, each of the one or more nodes comprises 10-100 micrograms of bioactive material. The number of nodes and the amount of bioactive material per node should be selected so as to avoid any potential of toxicity to the target animal(s).

[0116] In some configurations, each of the one or more nodes has a diameter of approximately 2 mm and a height of approximately 2 mm.

[0117] In some configurations, the one or more nodes 1 1 are flat and in line with an outer wall and the longitudinal axis of the stent body. As best shown in figure 4, the nodes 11 are flat structures such that they do not protrude in a way which could hurt the animal. As shown in the end view of figure 2 the nodes 1 1 are in line with the outer wall of the stent body 10.

[0118] Further, in some configurations as shown best in figure 4, the one or more nodes 11 are circular again to improve safety of the product and reduce the likelihood of causing damage to the animal e.g. from internal punctures due to the stent.

[0119] In some configurations, the stent insert 1 comprises a plurality of nodes 1 1 . In these configurations the stent insert 1 has two or more nodes 1 1. In some configurations, the stent insert 1 has four or more nodes 1 1. In some configurations, the stent insert 1 has eight or more nodes 11 . In some configurations, the stent insert 1 has twelve or more nodes 1 1 . In some configurations, the stent insert 1 has twelve nodes 11 . In some configurations, the nodes are located at one or both ends of the stent body 10. As shown in figure 1 , the nodes 1 1 are located at both ends of the stent body. In other configurations, the one or more nodes 11 are located at one end of the stent body.

[0120] In these configurations, the stent insert 1 comprising one or more nodes 1 1 can balance the intention to provide concentrated regions for dispersing the bioactive material, while allowing for the structural integrity and shape memory provided by the material of the stent body 10. This is because copper (or other similar metallic material) can be difficult to incorporate into the stent body 10 itself, while allowing for the elastic properties of the stent body. It should be understood that it may not be desirable to incorporate copper into the stent body 10 as it can make the stent more brittle, and therefore not provide or endure the desired manipulation of the stent body between the expanded and collapsed conditions.

[0121] Key Concept 4: Bioactive Coating

[0122] In some configurations, the stent insert 1 comprises a bioactive coating. With reference to figure 12, the bioactive coating is applied to the stent insert 1 and preferably across all stent surfaces. Bioactive material 12 is applied to the stent insert 1 to form the bioactive coating, whether by spraying or another application process. This bioactive material is released in the mammary gland 30 once the stent insert 1 is inserted into the animal.

[0123] The bioactive coating, when applied to all stent surfaces, can additionally prevent endothelialisation i.e. prevent excessive tissue growth on the stent insert 1 that might eventually block more isolated sites of bioactive material release (e.g. the nodes 1 1 if used without the bioactive coating).

[0124] In one configuration the thickness of the bioactive coating is 1 micron, and comprises between 1 gram to 3.5 grams of bioactive material on the stent surfaces. The total mass of the bioactive coating will be dependent on the total area of the stent surfaces, the coating material, and the thickness of the coating, which should be selected so as to avoid negatively impacting the elasticity of the stent body 10 and hence its shape memory. Preferably the thickness of the coating is no greater than 3 microns.

[0125] In some configurations where the one or more nodes 11 are present on the stent insert 1 , the bioactive material of the nodes can be the same as the bioactive coating. In other configurations the bioactive material of the nodes is different to the bioactive coating. In either case, the bioactive materials previously described (i.e. copper, zinc, silver, cobalt or a combination thereof) would be suitable options for the bioactive coating.

[0126] In some configurations, the stent insert 1 is covered by a nano-coating. The nanocoating of bioactive material allows it to bind to the stent body 10 effectively and be resistant to cracking of the coating as the stent insert 1 is manipulated between the expanded and collapsed conditions.

[0127] The process for applying the bioactive coating onto the stent insert 1 may be a physical vapor deposition (PVD) process, or alternatively a chemical vapor deposition (CVD) process. PVD and CVD processes allow for very fine, thin layers of coating to be applied without cracking, which can be an issue with other coating processes such as spraying.

[0128] The bioactive coating is an additional or alternative source of biomaterial of the stent insert 1 configured to be released in the mammary gland to prevent mastitis.

[0129] In some configurations, for example that shown in figures 13, 14 and 15, the stent insert 1 may have no nodes 1 1 and instead rely on the bioactive coating as the sole source of bioactive material.

[0130] Key Concept 5: Method of prevention, location and period of Operation

[0131] Following the description of the structure of the stent insert 1 and method of forming the same above, a general description of the method of using the stent insert 1 to prevent mastitis in a livestock animal will now be described.

[0132] To prevent mastitis in a livestock animal, a stent insert 1 above is provided. The stent insert 1 is inserted into a mammary gland of the animal in the collapsed condition. The stent insert 1 is released in the mammary gland 30 of the animal in the expanded condition.

[0133] As shown in figures 8 to 1 1, in some configurations, the stent insert 1 is introduced into the animal using an introductory tool 20. The introductory tool 20 inserts the stent insert 1 through a narrow passage in the animal and releases it into the targeted location for action. In some configurations, the stent insert 1 enters through a teat canal 31 of the animal as referenced in figures 8 and 10. The insertion method may make use of the introductory tool 20 and camera to locate the precise target location for release. During insertion, the stent insert 1 may be covered in a hydrophobic covering, which may help to retain it in the collapsed condition. The introductory tool 20 may retract / remove the hydrophobic covering in the process of releasing it into the targeted location.

[0134] In other configurations, the stent insert 1 is inserted into the animal by incision.

[0135] In some configurations, the stent insert 1 is left in the mammary gland 30 of the animal. Once the stent insert 1 is left in the mammary gland, the stent insert 1 releases the bioactive material at the mammary gland to prevent mastitis.

[0136] As shown in figures 8 and 9, in some configurations, the stent insert 1 is inserted into the gland cistern 32 of the animal.

[0137] In other configurations, as shown in figures 10 and 1 1 , the stent insert 1 is inserted into the teat cistern 33 of the animal.

[0138] The stent insert 1 is configured to be for insertion into livestock. The stent insert 1 is intended for non-human use. In particular, the stent insert 1 is designed for cattle for milking. For example, dairy animals / cattle for milking may include cows, goats, sheep, deer etc. These animals supply milk and may have issues stemming from bacterial growth in the mammary gland.

[0139] The stent insert 1 can be left in the animal for long periods of time. The stent insert 1 is left in the mammary gland 30 during lactation of the animal.

[0140] The stent insert 1 can be left in the mammary gland 30 during both lactation and dry periods of the animal.

[0141] In some configurations, the stent insert 1 is left in the mammary gland 30 of the animal permanently. The stent insert 1 may be retrievable when and if necessary and recyclable at any time retrieved including upon slaughter of the animal.

[0142] In some configurations, the stent insert 1 is configured such that when the stent insert 1 is in the mammary gland of the animal, milk may flow through the stent insert 1 from an opening at one end to an opening at the other end.

[0143] Although the invention has been described in relation to stent placement within the mammary gland and treatment of mastitis or other such infections, it will be appreciated that the stent insert 1 might also be suitable for use in other locations within an animal's body. For example, the stent insert 1 could be placed in the vascular system and hence release bioactive material (and / or other medications) directly into the bloodstream.

[0144] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims.

[0145] This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Claims

CLAIMS1. A stent insert for retention in a mammary gland of a livestock animal, the stent insert comprising: a stent body having shape memory having an expanded condition and collapsed condition, the stent body comprising a first material being at least partially elastic, wherein the stent body is elongate having a longitudinal axis; one or more nodes attached to the stent body, the nodes comprising a second material, the second material being a bioactive material for releasing at the mammary gland to prevent mastitis.

2. The stent insert as claimed in the previous claim wherein the stent insert is a dual material component where the first material of the stent body and second material of the one or more nodes are different.

3. The stent insert as claimed in any one of the previous claims wherein the one or more nodes are flat and in line with an outer wall and the longitudinal axis of the stent body.

4. The stent insert as claimed in any one of the previous claims wherein each of the one or more nodes comprises between 10 to 100 micrograms of bioactive material.

5. The stent insert as claimed in any one of the previous claims wherein the one or more nodes are circular.

6. The stent insert as claimed in any one of the previous claims wherein the stent insert comprises a plurality of nodes.

7. The stent insert as claimed in any one claims 1 to 6 wherein the stent insert comprises four or more nodes.

8. The stent insert as claimed in the previous claim wherein the stent insert comprises twelve nodes.

9. The stent insert as claimed in any one of the preceding claims wherein the nodes are located at both ends of the stent body.

10. The stent insert as claimed in any one of claims 1 to 8 wherein the one or more nodes are located at one end of the stent body.

11. The stent insert as claimed in any one of the previous claims further comprising a bioactive coating.

12. The stent insert as claimed in the previous claim wherein the bioactive coating has a thickness of less than 3 microns.

13. The stent insert as claimed in the previous claim wherein the bioactive coating has as thickness of approximately 1 micron.

14. The stent insert as claimed in any one of claims 11 to 13 wherein the bioactive material of the nodes is the same as the bioactive coating.

15. The stent insert as claimed in any one of the previous claims wherein the bioactive material is an antimicrobial.

16. The stent insert as claimed in any one of the previous claims wherein the bioactive material is one or a combination of copper, zinc, silver, and / or cobalt.

17. The stent insert as claimed in any one of the previous claims wherein the first material is one or a combination of nitinol, titanium, and / or chromium.

18. The stent insert as claimed in any one of the previous claims wherein the stent body comprises filaments to form an interwoven mesh.

19. The stent insert as claimed in any one of the previous claims, wherein the shape memory of the stent body allows for cyclical contraction and expansion of the stent body to accommodate pulsation of the mammary gland.

20. The stent insert as claimed in the previous claim wherein the stent body is rated to endure at least 100 million pulsation cycles.

21. The stent insert as claimed in any one of the previous claims wherein the stent insert in the expanded condition has a length of between 5 to 60 mm.

22. The stent insert as claimed in any one of the previous claims wherein the stent insert in the expanded condition has a diameter of between 2 to 30 mm.

23. The stent insert as claimed in any one of the previous claims wherein the stent insert collapses to less than a fifth of its expanded diameter upon moving to the collapsed condition.

24. The stent insert as claimed in any one of the preceding claims wherein the stent insert comprises a first open end, a second open end and an unobstructed passage along the longitudinal axis of the stent body from the first open end to the second open end.

25. The stent insert as claimed in claim 24 wherein the stent insert is configured such that milk may flow through the unobstructed passage from the first open end to the second open end.

26. The stent insert as claimed in any one of the preceding claims wherein the stent body is tapered at the first open end or the second open end or both.

27. A method of preventing mastitis in a livestock animal, the method comprising: providing a stent insert, the stent insert comprising a stent body having a shape memory, having an expanded condition and a collapsed condition, and being at least partially elastic, wherein the stent body is coated with and / or comprises nodes of a bioactive material for releasing at the mammary gland to prevent mastitis; inserting the stent insert into a mammary gland of the animal; releasing the stent insert in the mammary gland of the animal in the expanded condition; leaving the stent insert in the mammary gland of the animal;the stent insert releasing the bioactive material at the mammary gland to prevent mastitis.

28. The method as claimed in the previous claim further comprising leaving the stent insert in the mammary gland during lactation of the animal.

29. The method as claimed in the previous claim further comprising leaving the stent insert in the mammary gland during both lactation and dry periods of the animal.

30. The method as claimed in the previous claim further comprising leaving the stent insert in the mammary gland of the animal permanently.

31. The method as claimed in any one of claims 27 to 30 wherein the stent insert is inserted in the collapsed condition.

32. The method as claimed in any one of claims 27 to 31 further comprising guiding the stent insert into the mammary gland of the animal using an introductory tool.

33. The method as claimed in the previous claim wherein the stent insert is provided with a hydrophobic covering which is removed or retracted by the introductory tool as the stent insert is released.

34. The method as claimed in claim 32or 33 wherein the stent insert is inserted through or into a teat canal of the animal.

35. The method as claimed in any one of claims 27 to 31 wherein the stent insert is inserted into the animal by incision.

36. The method as claimed in any one of claims 27 to 35 wherein the stent insert is inserted into the gland cistern of the animal.

37. The method as claimed in any one of claims 27 to 35 wherein the stent insert is inserted into the teat cistern of the animal.

38. The method as claimed in any one of claims 27 to 37 wherein the animal is nonhuman.

39. The method as claimed in the previous claim wherein the animal is cattle for milking.

40. The method as claimed in any one of claims 27 to 39 wherein the stent insert comprises a first open end, a second open end and an unobstructed passage along the longitudinal axis of the stent body from the first open end to the second open end.

41. The method as claimed in any one of the preceding claims, further comprising milking the cow, wherein milk flows through the unobstructed passage.

42. The method as claimed in any one of claims 27 to 41, wherein the stent body is tapered at the first open end or the second open end or both.

43. A method of manufacturing the stent insert as claimed in any one of claims 1 to 26, the method comprising: forming the stent body; and attaching the nodes to the stent body.

44. The method as claimed in the previous claim wherein attaching the nodes is achieved by marker pressing, stamping, fusing, or hydraulic pressing.

45. The method as claimed in claim 43 or 44, further comprising applying a bioactive coating to the stent insert.

46. The method as claimed in the previous claim wherein applying the bioactive coating onto the stent insert is a physical vapor deposition (PVD) process.

47. The method as claimed in claim 45 wherein applying the bioactive coating onto the stent is a chemical vapor deposition (CVD) process.

48. The method as claimed in any one of claims 43 to 47 wherein forming the stent body is achieved by laser cutting from a tube of the first material.

49. The method as claimed in any one of claims 43 to 47 wherein forming the stent body is achieved by knitting or braiding the first material.

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