A WEARABLE ARTICLE AND A METHOD FOR PRODUCING A WEARABLE ARTICLE
20200253304 ยท 2020-08-13
Inventors
Cpc classification
C12N11/02
CHEMISTRY; METALLURGY
International classification
Abstract
The invention provides a glove (9) formed of an elastomeric material and having a surface (2), wherein a stabilized probiotic is provided on a part of the surface (2) forming an active layer (3), and the part of the surface (2) contacts the skin (21) of the wearer. The invention also provides a wearable article, a method for producing an elastomeric glove (9), and a method for producing a wearable article.
Claims
1. A glove formed of an elastomeric material and having a surface, wherein a stabilized probiotic is provided on a part of the surface to form an active layer, and the part of the surface contacts the skin of the wearer.
2. A glove according to claim 1, wherein the active layer is provided on the whole of the skin contacting surface.
3. (canceled)
4. A glove according to claim 1, wherein the active layer extends to a depth of 0.01 to 10 microns below the surface.
5. A glove according to claim 1, wherein the active layer has a thickness in the range 1 micron to 0.5 mm.
6. A glove according to claim 1, wherein the probiotics comprise microbes that make up part of a normal person's skin flora.
7. A glove according to claim 1, wherein the concentration of probiotics in the active layer is present in amounts of greater than 1000 CFUs per cm.sup.2, or alternatively in the range of 500 to 5000 CFUs per cm.sup.2.
8. A glove according to claim 1, wherein the probiotics are encapsulated within vesicles.
9. A glove according to claim 8, wherein the vesicles have an average largest measurement across of between 1 and 300 microns.
10. A glove according to claim 1, wherein at least some of the vesicles burst when the article is worn to transfer at least some of the probiotics to the skin of the wearer.
11. A glove according to claim 1, wherein the active layer is in the form of a powder.
12. A glove according to claim 1, wherein the active layer is in the form of a fluid, cream or gel.
13. (canceled)
14. A glove according to claim 1, wherein the active layer has been sprayed onto the surface using one or more spray guns.
15. (canceled)
16. A wearable article having a surface, wherein a stabilized probiotic is provided on a part of the surface.
17. A method for producing an elastomeric glove, the method comprising: forming the material for making the glove into a desired shape; and providing stabilized probiotic material on a skin contacting surface of the glove to form an active layer.
18. A method according to claim 17, wherein providing the material on at least part of the surface comprises spraying the material onto the surface using a spray gun.
19. (canceled)
20. A method according to claim 17, further comprising, prior to providing the material on the surface, encapsulating the probiotic material within vesicles.
21. (canceled)
22. The method of claim 17, wherein a former is used to form the desired shape and the method further comprises peeling the glove from the former so that the exterior surface when on the former becomes the interior surface of the glove.
23. The method of claim 17, wherein the stabilized probiotic material is formed into a mist using ultrasonic atomization before being applied to the glove.
24. (canceled)
25. The method of claim 24, wherein the gloves are passed through the tunnel on a conveyor belt.
26. A method for producing a wearable article, the method comprising: forming the material for making the wearable article into a desired shape; and providing stabilized probiotic material on at least part of a surface of the article.
27-30. (canceled)
Description
[0044] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:
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[0058] Gloves formed from elastomeric materials are used in healthcare practices and when carrying out veterinary work in order to prevent the spread of pathogens and to protect patients and workers from infection. As mentioned above, current protocol dictates that these gloves must be worn whilst carrying out certain procedures and must be changed after each procedure or if contact is made with substances that are likely to be infectious. The same is also true of most other personal protective equipment worn in such environments such as facemasks, eye protection and any other item of protective clothing. Although the specific examples in the description below refer to a glove or gloves, the invention is applicable to any other article, which may be a protective article, wherein probiotics are applied to any skin contacting surface. Here a skin contacting surface refers to any part of the article that is skin facing and could touch the skin when the article is worn. Some parts of the skin contacting surface may not always actually touch the skin. As an example, in the case of a glove the entire interior surface of the glove would be referred to as skin contacting. However, when worn by some users the interior surface at the very tips of the fingers or in a crease may not actually ever directly contact the wearer.
[0059] An active layer of stabilized probiotics can also be applicable to garments worn outside of the healthcare environment. The sole of a gym shoe or an incontinence garment, for example, could comprise an active layer including probiotics which could help to reduce the growth of bad-smelling or harmful bacteria. An efficient way to apply the active layer to a gym shoe might be to apply the probiotics in a spray form. A spray bottle or a bottle with holes in the lid containing the stabilized probiotics in liquid or powder form could be sold to the user so that the layer could be reapplied easily.
[0060]
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[0063] Probiotics can be applied only to the interior surface of the glove, only to the exterior of the glove or to both the interior and the exterior of the glove. It is preferable that at least the interior surface is provided with an active layer because it is the practitioner who is likely to be suffering from conditions such as irritant contact dermatitis which will make them more susceptible to infection and transfer of the microorganisms to the skin will be more effective for the wearer. Applying probiotics to the outside of medical gloves may be problematic in that conditions on the skin or body of a patient must be carefully controlled and applying additional substances may interfere with this environment.
[0064] The normal skin flora contains both resident and transient microorganisms and in a normal person there may be 1000s of bacteria (or 1000s of colony forming units) present on one square centimetre of skin. Of the resident bacteria, staphylococcus epidermis is the most common with corynebacteria such as diphtheroids also playing a prominent role, particularly on the palm of the hand. Some of the bacteria forming part of the normal skin flora, such as Staphylococcus aureus, can be pathogenic while others are considered harmless. The amount of transient bacteria on an individual's skin can vary greatly from person to person and will depend on the level of moisture and acidity of the skin as well as the temperature. The proportion of different microbes present does, though, tend to be fairly consistent for each adult. As well as variations between populations on the skin of different individuals, the prevalence of different microbes depends on the part of the body inhabited. Normal flora can be divided broadly into three types in each of which the natural levels of different types of bacteria is balanced differently. The hands, face, and trunk fall into the same category which means that the combinations, proportions and concentrations of bacteria which make up normal skin flora for the hands will also represent something close to the normal skin flora on the face and trunk.
[0065] The different probiotics within the active layer applied to the wearable article are preferably harmless as well as being able to compete as effectively as possible with pathogenic bacteria on the skin. The active layer applied when forming an elastomeric glove may be manufactured to represent as closely as possible the normal proportion of each type of bacteria (or each type of non-pathogenic bacteria) found on the skin of the hand. The levels could be different for an article designed to contact a different part of the body. There is obviously a fair amount of variation in the proportions and quantities of the different types of bacteria present in the skin flora of different people and so an average should be taken. Normal skin flora here thus refers to the average amount of each microbe that would be observed in a spread of people covering all sectors of the world's population. There may, in any case, be a significant spread in the values that can be considered normal.
[0066] Alternatively, only the most prominent or the most prominent few bacteria commonly present on the skin may be used in the active layer in order to simplify production. The normal skin flora is highly dependent on the region of the body concerned and, as mentioned above, the face, trunk and hands tend to display a similar balance of at least the most prevalent bacteria. This means that applying the same composition to an active layer within articles intended to contact the face, hands and trunk can still represent (at least to an extent) the natural skin flora of these regions without having to alter the make-up of the active layer. Probiotics can also be chosen to represent those that will most effectively help to control pathogenic growth on the skin. It is not necessary that these form a part or a substantial part of normal skin flora, for example Bacillus subtilis, Bacillus pumilus and/or Bacillus megaterium can be used, as for, and possibly in similar proportions to those used in the cleaning products mentioned above.
[0067] Because the normal skin flora may also vary in its make up depending on certain characteristics of the wearer, in an embodiment articles may be specifically designed to replicate the composition of the skin flora expected for that particular type of person. On the other hand, since use of different compositions for the active layer may be costly and time consuming, it will likely be more efficient to provide a single composition for use in all articles produced.
[0068] The concentration as well as the relative proportion of different probiotics present in the active layer may be made to represent the normal skin flora (or to supplement this) and as bacteria may be present in amounts of over 1000 colony forming units per square centimetre on the skin (depending which part of the body is concerned). A higher concentration, for example a concentration of around 5000 colony forming units per square centimetre, may also be applied to the surface of the wearable article to allow for death of some organisms during manufacture, storage, and transport and for a failure to transfer to the skin of the wearer (due to containing vesicles remaining intact, for example).
[0069] The probiotics applied to the surface of a wearable article must be capable of surviving throughout the period during which the product is stored and distributed. Medical gloves and other disposable supplies are generally purchased in bulk and stored until they are required. Depending on the number of staff and the rate at which gloves are used the gloves may need to be stored for months or even years. The material must therefore be stabilized to allow them to survive for long periods.
[0070] Stabilizing refers to limiting the exposure of microorganisms to stimulating environmental conditions such as warmth and moisture in order that their numbers remain fairly constant and they can remain viable. Methods of stabilizing probiotics have been studied widely. This has generally been with a view to their use in the pharmaceutical industry as ingestible substances for rebalancing gut flora. Probiotics have traditionally required storage at below room temperature. While it is possible to store medical gloves and the like in a cooled environment such as a fridge, this is costly and not ideal. More recent methods of stabilization do, however, allow probiotics to survive at room temperature for extended periods. WO-A-2005/047489, for example, describes a method for producing a fine powder containing probiotics which can remain stabilized at room temperature. Freeze or spray dried bacteria concentrate is added to a stabilizer having a low water content in order to achieve this.
[0071] In a preferred embodiment the probiotic material is in an encapsulated form when applied to the glove or wearable article. The probiotic substance is thus contained in a plurality of microscopic vesicles which can help to protect the probiotics from the environment. These vesicles must be strong enough to survive transport and storage but must be able to release probiotics when the glove or article is worn to release these on to the surface of the skin.
[0072] One commonly used method for producing encapsulated probiotics (usually for use in edible capsules) is by spray-drying. Probiotics in suspension within a matrix are atomized and then dried by directing the atomized particles at high velocities through a stream of hot air. Protectants can be added to reduce the chances of probiotics dying due to the heat of the drying step, however these will not usually be completely effective and the success of this method will depend on the particular cocktail of probiotics used. Spray-cooling uses similar techniques, but employs a cold rather than a hot stream of air to dry the particles.
[0073] Fluid-bed agglomeration and coating involves fluidising particles of the material to be coated and then spraying with an atomized substance. Coating materials are generally lipid based but carbohydrates and proteins can also be used. Freeze drying is another widely used encapsulation technique. During freeze drying, particles containing the probiotics along with a carrier material are subjected to freezing temperatures followed by sublimation of water from the particle in a vacuum. A cryoprotectant (or cryoprotectants) can be added to prevent the cold temperatures from killing the microbes. Vacuum drying works similarly but without reducing the temperature to below zero.
[0074] During emulsification, water is mixed well with a hydrophobic substance such as oil (along with an emulsifier) and probiotics are trapped within droplets of the oil. Other known techniques used to produce encapsulated particles include coacervation, extrusion, and dripping, among others. These are described in detail in, for example, the article Encapsulation Technology to Protect Probiotic Bacteria by Chvarri, Maran and Villarn.
[0075] All of the above techniques can result in a stabilised mixture and may be suitable for use in producing a wearable article having an active probiotic layer; however any method for stabilising probiotics can be used.
[0076] Vesicles that are substantially spherical will generally result from some of the techniques described above. Spherical vesicles for use in the present invention will preferably have diameters in the range of 1-300 microns. If the vesicles used are not spherical, or a mixture of shapes is included, then the average size of the largest measurement across for all of the particles may be in the range of 1-300 microns. If the vesicles have an elongated form, for example, the particles may measure 1-300 microns on average along their longest dimension.
[0077] Although a stabilised probiotic substance which is not contained within vesicles can be used to produce the wearable article of the invention, vesicles are easy to apply, as will be described in more detail below, and will maintain the probiotic material in a stable state on the surface of the glove or article until pressure is applied by the skin of a wearer. In order to apply the stabilized probiotics to the surface of an elastomeric article a powder, fluid, cream or gel comprising the vesicles must be applied to the surface at the correct stage during manufacture. It is vital that the temperature of the article and environment during application is not so high that the probiotics within the vesicles are killed. More specifically, it is preferable that at least 90% of the microbes are still viable immediately following manufacture of the article. In embodiments, in order to bind the vesicles to the article, it is also preferable that the material of the article is not completely cured or solidified at the time of application. In this way an active layer of probiotic material is applied to the surface and may be embedded to some extent within it. The active layer can also include additives such as hydrating substances or adhesives.
[0078] The glove or other wearable elastomeric article may be formed of a polymeric/elastomeric material such as latex, nitrile, vinyl, neoprene, polyurethane, butyl, any other elastomeric material or a combination of two or more materials, the combination of which has elastomeric properties. These articles are generally manufactured using dip moulding techniques. In the case of latex or nitrile gloves, for example, the raw material is a water-based emulsion of rubber particles to which sulphur is added which helps to initiate cross-linking and cause polymers to form. Formers (or moulds) having the desired shape are dipped into the modified emulsion and the emulsion is allowed to dry. The thickness of the skin formed on the former will depend on the viscosity of the emulsion into which the former is dipped, the speed of dipping and/or the number of times the former is dipped. After cooling, the article is removed from the former to finish. Processes for forming articles from other elastomeric materials are similar. These are well known in the art and are not described herein. It is worth mentioning, however, that the production of the elastomeric article will generally involve a cooling or hardening step.
[0079] The probiotic vesicles should be applied during the normal manufacture of an elastomeric article at a point when the cooling or hardening process is not yet complete and thus the material of the article is not fully hardened. At this point the vesicles may embed themselves to an extent into the surface of the article as shown in
[0080] Preferably, the vesicles will be sprayed onto the article at the optimum temperature or optimum hardness of the surface using a nozzle having small holes through which vesicles can pass. Preferably the nozzle holes will be sized so that the probiotic mixture can be easily applied while still being separated sufficiently to provide an even coating. If a uniform coating over the whole surface of the article is desired, the spray gun can be rotated around the article while it is on the former (or the article and former rotated in combination) in order to cover the whole surface. If only portions of the surface are desired to be coated then a template can be held over the article in order to spray only the required regions.
[0081] Generally, a substantially uniform coating covering the whole of the article will be the most effective and the most efficient in that it will result in the least amount of wastage. Spraying smaller regions, such as only the interior parts of a glove that will contact fingertips and palms, will save on material whilst still protecting from colonisation by pathogens after glove removal (these being the regions most likely to come into contact with pathogenic material). Several spray guns orientated around the article can also be used to avoid the need for rotation. In order to achieve an even coating the spray gun nozzles will preferably be located at a distance of between 5 and 200 centimetres from the surface of the article at the point at which the article is closest to the spray gun nozzle concerned, however this will depend on the type of spray gun used. Using spray guns in this way allows for easy application of the probiotic layer with minimal adaption of the traditional manufacturing processes used to produce the wearable elastomeric articles that are currently available. The spraying process can be completely automated to allow it to be integrated into an existing production line.
[0082] It is also possible to add an adhesive material to the plurality of vesicles in order to better adhere the probiotic layer to the article. The mixture with adhesive can be applied before the surface material has cooled completely (for example with a spray gun as described above). Alternatively, the mixture with adhesive can be applied after curing and cooling of the article. Adhesive can be applied to the surface of the elastomeric article post-cure and the vesicles applied on top of this. Vesicles applied after the article has cured and cooled will not be embedded within the surface. This may make them more likely to burst during storage and their attachment to the surface may not be as strong.
[0083] Vesicles can be provided in a fluid, gel or cream (which may be produced in certain embodiments by adding vesicles in the form of a powder to the fluid, gel or cream) and these can also be applied to the surface of the article either during or after curing. The use of a fluid, gel or cream may be particularly advantageous where the article to which the probiotic layer is applied is formed of latex as it may prevent aerosols from being released when the wearer removes the article. However, applying the vesicles before cooling in powder form will also achieve this affect because they will be held in place on the surface. Probiotics in a fluid solution can be sprayed onto the surface of the article as described above.
[0084] Whichever way the probiotic material is applied, the elastomeric article resulting from the processes described above will have an active probiotic layer provided on at least a part of the surface. In this context the active layer refers to a region either above the surface of the elastomeric article or partly extending into the surface of the elastomeric article (depending on the application technique used) and including the probiotic material.
[0085] During manufacture of an elastomeric glove the former is in the shape of a hand and removal of the article from the former will be by peeling, so that the outer surface of the article when on the former will end up as the interior surface of the glove. The process of peeling the glove 9 from the former 10 is shown in
[0086] The vesicles may comprise an outer coating or skin to contain the probiotics. This coating must be strong enough to allow the vesicle to hold its form during storage but weak enough that the vesicle can burst when the article contacts the skin of the wearer. In embodiments, the skin may be formed of a material that is soluble or part-soluble so that moisture on the users hand will dissolve the vesicle coating to release the probiotics held inside. The resulting articles in this case will need to be stored in very dry conditions which may not always be possible.
[0087] Deformation of the containing elastomeric material which occurs when the article is worn can also provide a force on the vesicles which can burst them. In general, the article will be small enough that it will need to be stretched slightly to fit over the relevant body part (such as the hand in the case of an elastomeric glove). Because vesicles are embedded into the surface material and will tend to attach themselves to it once the material has cured, the stretching of the material surrounding the vesicles may be enough burst them once they are worn as shown in
[0088] In embodiments, the vesicles are embedded deep enough in the surface of the article that pressure applied perpendicular to the surface will not be sufficient to burst the vesicles. This way articles can be stored so that they are laid one on top of another without risk of vesicles bursting and the probiotics becoming destabilized. In this case stretching of the material will be required to break the vesicles when the wearer puts on the wearable article. In other embodiments the vesicles can burst on application of pressure perpendicular to the surface. If this is the case then the article does not need to stretch to such an extent when worn (vesicles are broken under pressure from the skin of the wearer, in particular during use). If there is likely to be enough perpendicular force on the vesicles during storage then the articles may need to be kept in boxes or in smaller piles in order that pressure is not applied to burst the vehicles during transport or storage.
[0089] A preferred method for providing the probiotic layer on elastomeric gloves is described below. Although the specific example of an elastomeric glove is described, the method can be used to apply a probiotic layer to other articles.
[0090] The method comprises passing gloves on their formers through a tunnel containing a thin mist made up of droplets of a fluid containing the probiotics. This mist is produced using an ultrasonic atomization technique. Ultrasonic nozzles make use of high frequency vibrations (produced by piezoelectric transducers) to set up waves in a film at the nozzle tip. Once a particular amplitude for the waves is reached, droplets of the film fall off forming a mist. This technique allows an extremely fine mist to be produced and characteristics of the mist (such as particle size) can be extremely accurately controlled by adjusting the properties of the vibrations used.
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[0092] The tunnel may be formed of any waterproof material and may be permanently erected or collapsible and removable to provide some flexibility. In addition, the tunnel need not necessarily be cylindrical and can be any shape, for example a cuboid. In place of a conveyor belt, gloves may be hung from a moving frame and passed through the tunnel in this way.
[0093] Although the application method will work with one spraying apparatus only, it is preferable for several apparatus (each with one or more spray nozzles) to be spaced around and along the inner surface of the tunnel for application of an even coat of fluid to the gloves. Nozzles may be positioned around the entrance to the tunnel (and/or around the exit) and may be positioned at equal intervals around the mouth of the tunnel. For example, twelve spraying apparatus may be positioned at 30 degree intervals around a circular entrance and/or exit. In addition, spray apparatus may be positioned at intervals along the inside of the tube, for example every meter. Several tubes may pass from the reservoir to different nozzles or systems of nozzles positioned at intervals along the tunnel or the tube may comprise several outlets leading to each of the nozzles. Preferably, nozzles are spaced at equal intervals along the tunnel and around the circumference or perimeter to provide as even a coating as possible.
[0094] Because the density of the mist contained within the tunnel is fairly consistent, the resulting coating of probiotic fluid applied will uniform or close to uniform. The outer surface of the glove while on the former will eventually form the inner surface of the glove (which will contact the skin of the wearer during use) so that the coating applied within the tunnel is to the eventual inner surface of the glove. The thickness of the coating can be adjusted as desired by changing the length of the tunnel or the density of the mist produced within it.
[0095] In addition, the length of the tunnel may need to be adjusted depending on the speed of the production line (which may affect the speed at which the conveyor belt moves) to ensure that a coating of the desired thickness is applied. The possibility of adjusting the length of the tunnel to suit the production process ensures that the manufacturing process is changed as little as possible by application of the probiotic layer. Incorporating this step into a traditional manufacturing process should thus be cheap and straightforward, such that the benefits of providing a glove having the probiotic layer will outweigh any additional cost in producing, and therefore in obtaining the gloves.
[0096] The gloves can be passed through the tunnel during the normal hardening process. As a result the application of the probiotic layer does not increase the manufacturing time and requires minimal adjustment to the process currently used to produce traditional elastomeric gloves without a probiotic layer. While the probiotics can be applied by submerging gloves in a bath of probiotic fluid or using a conventional spray pistol, the ultrasonic spraying technique described above is preferable in that it does not slow down the production process and it provides a dry feel to the final product which is more comfortable for the wearer.
[0097] Embodiments of the present invention have been described with particular reference to the examples illustrated. However, it will be appreciated that variations and modifications may be made to the examples described within the scope of the present invention.