WO2012007723A1

WO2012007723A1 - Anti-microbial products

Info

Publication number: WO2012007723A1
Application number: PCT/GB2011/001060
Authority: WO
Inventors: Roger French
Original assignee: Luxion Holdings Limited
Priority date: 2010-07-14
Filing date: 2011-07-14
Publication date: 2012-01-19
Also published as: GB201011801D0

Abstract

A flexible lightweight laminar material comprises a woven mesh (1) of copper wires. The wires may for example have an average diameter (3) of roughly 50 microns, and are woven with at least 200 wires per inch, defining a plurality of apertures having an average diameter (4) of roughly 75 microns. Ideally, the copper wires comprise high- purity copper, containing 99.9% copper or higher. The copper wires (52) may be twisted together with conventional thread (53) of a similar diameter in order to support finer, more active copper wires, allowing weaves of 400 wires or more per inch, and aperture diameters of as low as 15 microns. The material shows excellent anti-microbial properties, even against MRSA, and also transmits heat well. Devices that are made with the material include bed sheets (5), wound dressings (9), catheter dressings (20), sphygmomanometer cuffs (24), tourniquets (26), face masks (13), anti- wrinkle devices (16), undergarments (30), nipple shields to obviate infection via mother's milk, feminine hygiene products, baby carriers (61), clothing fabrics (71) and hydrogel wound dressings (81).

Description

ANTI MICROBIAL PRODUCTS

The present invention relates to products for medical and general health use containing metallic copper. More particularly, but not exclusively, it relates to such products for personal use having bacteriostatic and/or antimicrobial effects.

The prevention and control of infection is an area of major concern at present. The most prominent current issue is probably methacillin-resistant Staphylococcus aureus (MRSA), which is believe to be capable of contaminating both hard and soft surfaces for prolonged periods, creating a reservoir for infection. Clostridium difficile (C. diff) is also of increasing concern. When this occurs in situations such as in hospitals, persons with already weakened health are at risk of infection by MRSA, C. diff and other such bacteria, and the danger to health is considerable.

Other forms of virulent bacteria and other infectious micro-organisms are also of concern, including both potentially lethal organisms, such as some strains of influenza, and potentially incapacitating organisms, such as norovirus and Enterobacter coli (E. coli). Additionally, fungal infections, and bacterial skin conditions such as acne, are rarely life- threatening, but can be debilitating and unsightly. It is therefore desirable to reduce or eliminate contamination with infectious microorganisms, and/or to reduce or eliminate such micro-organisms subsequent to infection.

Additionally, initial surface contamination with micro-organisms frequently occurs at very low levels, with subsequent multiplication of the infectious micro-organisms until they reach dangerous levels. It is hence desirable to prevent significant multiplication, even if trace contamination should remain. In the case of bacterial contamination, this effect is referred to as "bacteriostasis", although similar concepts apply for contamination with micro-fungi, viruses and other sources of infection.

Metallic copper, for example in the form of bracelets, is widely used as a form of self- medication for arthritis. There are also some observations that solid copper objects may have a bacteriostatic effect. However, bodies of solid copper is unlikely to be convenient in most situations, except for objects such as door handles, fingerplates, and some flat hard surfaces.

It is hence an object of the present invention to provide means whereby the potential benefits of metallic copper may be extended to more applications and whereby it may be possible to extend the efficacy of copper beyond mere bacteriostasis.

According to a first aspect of the present invention, there is provided a device to improve the health of a human or animal subject, comprising a zone of a substantially laminar material provided with a plurality of aperture means and comprising a plurality of elongate metallic wire means, each said wire means comprising at least 65% by mass metallic copper, and means to locate said zone of material adjacent a portion of body tissue to be treated.

Preferably, said apertured laminar material comprises a mesh of said metallic wire means.

Advantageously, said apertured laminar material comprises a woven mesh of elongate metallic wire means defining the aperture means.

Preferably, said metallic wire means comprises at least 80% by mass metallic copper.

Advantageously, said metallic wire means comprises at least 90% by mass metallic copper, optionally at least 95% by mass metallic copper.

The metallic wire means may comprise at least 99% by mass metallic copper. The metallic wire means may comprise less than 0.3% by mass phosphorus. The metallic wire means may comprise less than 0.01% by mass phosphorus. The metallic wire means preferably comprises less than 0.005% by mass oxygen. Preferably, said metallic wire means has an average diameter of less than 0.2mm. Advantageously, said metallic wire means has an average diameter of less than 0.1mm. Optionally, said metallic wire means has an average diameter of between 0.02 and 0.06mm.

Preferably, said apertured laminar material is provided with a plurality of aperture means having an average diameter of less than 0.2mm.

Advantageously, said apertured laminar material is provided with a plurality of aperture means having an average diameter of less than 0.1mm.

Optionally, said aperture means have an average diameter of less than 75 micrometers.

The aperture means may have an average diameter of less than 25 micrometers.

Preferably, each said elongate metallic wire means extends substantially across said zone of apertured laminar material.

Said apertured laminar material may consist substantially of said metallic wire means alone.

Alternatively, said metallic wire means may each be twisted together with elongate natural or artificial polymeric fibre means to form elongate composite fibre means.

Preferably, said composite fibre means are formed into said woven mesh.

Preferably, said natural or artificial fibre means have a diameter approximately equal to that of the metallic wire means. The composite fibre means thus comprises approximately equal volumes of the metallic wire means and the natural or artificial fibre means.

The composite fibre means thus comprises approximately 90% by mass of the metallic wire means.

It should be noted that it is the content of copper and other elements in the metallic wire means that appears to be of most importance, even when the metallic wire means is incorporated into the composite fibre means, reducing the net content of copper and other elements in the apertured laminar material as a whole.

Preferably, said apertured laminar material is substantially flexible.

In a first embodiment, the device comprises bedding means.

Said bedding means may comprise sheet means adapted to be mounted to bed means.

Preferably, the zone of apertured laminar material of the device is dimensioned to extend across substantially an entire upper, in use, surface of mattress means of the bed means.

Advantageously, the sheet means comprises peripheral zones of fabric material.

Said peripheral fabric zones may be adapted to be disposed beneath the mattress means so as to secure the sheet means thereto. Said peripheral fabric zones may be configured to extend adjacent one or more sides and at least part of a lower, in use, surface of the mattress means.

Said bedding means may comprise cover means for a padded bedding item, such as duvet, pillow or cushion means.

In a second embodiment, the device comprises dressing means for a wound or infected area of body tissue.

Preferably, the dressing means comprises laminar backing means having the zone of apertured laminar material mounted to one face thereof, said laminar backing means comprising or being provided with means so to secure the dressing means to a human or animal body that the zone of apertured laminar material is in contact with wounded and/or infected tissue.

Advantageously, the laminar backing means is provided with adhesive means adapted to secure the dressing means temporarily to a body surface adjacent the wounded and/or infected tissue.

Alternatively, the laminar backing means is adapted to be wrapped around a part of the human or animal body. The laminar backing means may be provided with selectably releasable securing means, such as co-operable patches of respective components of a hook-and-loop repositionable fastening fabric, or tie-string means.

The backing means may be resiliently extensible.

The backing means may comprise fabric backing means or a plastics sheet material.

Said plastics sheet material may optionally be impervious to moisture.

In a preferred form of this embodiment, the dressing means comprises a layer of gel material, advantageously hydrogel material, disposed between the backing means and the apertured laminar material.

The gel material is thus so located as to pass through aperture means of the apertured laminar material as it migrates to said wounded and/or infected tissue.

In a third embodiment, the device comprises means to improve a cosmetic appearance of a skin surface, said skin surface optionally comprising wrinkles, scars and/or other surface lesions.

Preferably, the device then comprises supporting means wearable around a part of the body, having the zone of apertured laminar material so mounted thereto as to be maintainable in contact with the lesions to be treated. Said supporting means may be resiliently extensible and/or provided with selectably releasable securing means and/or adhesive means temporarily securable to a body surface.

In a fourth embodiment, the device comprises breathing mask means wearable over a mouth and nose of a human or animal.

Said breathing mask means may be worn by an infected individual to obviate emission of exhaled infectious micro-organisms or by an individual to obviate inhalation of infectious micro-organisms.

Preferably, the breathing mask means is so adapted that substantially all inhaled and exhaled air passes through the zone of apertured laminar material.

The breathing mask means may comprise a zone of porous fabric material at least coextensive with the zone of apertured laminar material, and disposed externally of the zone of apertured laminar material in use.

In a fifth embodiment, the device comprises a nipple shield adapted to obviate transfer of infection from a nursing mother in her milk.

Preferably, the nipple shield comprises an outer surface suitable for contact with an infant's mouth.

The nipple shield may be provided with adhesive means adapted to fasten the shield temporarily in an operative position. Optionally, the nipple shield comprises part of a device to express milk for subsequent feeding to an infant.

In a sixth embodiment, the device comprises a medical device contactable in use with a skin surface of a subject and said zone of apertured laminar material comprises a skin- contacting surface of the device.

Preferably, said apertured laminar material extends over at least an entire skin-contacting surface of the device.

The device may comprise sphygmomanometer cuff means.

The device may comprise tourniquet means.

In a seventh embodiment, the device comprises garment means.

Preferably, said garment means is adapted to be worn in contact with or adjacent a body surface.

Said garment means may be adapted to cover at least part of a wearer's limbs. Said garment means may be adapted to cover a wearer's head, hand or foot. Alternatively, the garment means may comprise an outer garment adapted to equilibrate a body surface temperature of a wearer across a portion of the body covered by the garment means.

In an eighth embodiment, the device comprises an item of footwear or a portion thereof.

Said portion of the item of footwear may be removable therefrom, optionally comprising removable insole means.

In a ninth embodiment, the device comprises a feminine hygiene product.

In a tenth embodiment, the device comprises a carrying device adapted to carry a baby.

Preferably, said baby-carrying device comprises pouch means adapted to hold the baby, said pouch means being adapted to be held against a body of a person carrying the baby with at least a wall of the pouch contactable with the body of said person comprising said apertured laminar material.

Advantageously, the baby-carrying device further comprises sash means mounted to the pouch means and wrappable around the body of said person.

Said sash means and optionally a remainder of the pouch means may also comprise said apertured laminar material. Body heat from the person carrying the baby may thus be conducted to the baby in order to maintain a body temperature of a premature or unwell baby; body heat from an overheated baby may conversely be conducted away from the baby to the person carrying the baby.

According to a second aspect of the present invention, there is provided an apertured laminar material suitable for use in the devices of the first aspect above, comprising a woven mesh of metallic wire means, said wire means comprising at least 90% by mass metallic copper.

Preferably, said wire means comprises at least 99% by mass metallic copper.

Said wire means may comprise at least 99.9% by mass metallic copper.

Said wire means may comprise less than 0.01% mass phosphorus.

Said wire means may comprise less than 0.005% by mass oxygen.

The metallic wire means preferably define aperture means of the material therebetween.

In a preferred embodiment, the metallic wire means are each twisted together with elongate natural or artificial polymeric fibre means to form composite fibre means, said composite fibre means being woven into said woven mesh.

Said natural fibre means may comprise a fibre selected from cotton and silk. Said artificial polymeric fibre means may comprise a fibre selected from polyester, polyamide, cellulosic and para-aramid fibres.

Preferably, said natural or artificial fibre means have a diameter approximately equal to that of the metallic wire means.

The composite fibre means thus comprises approximately equal volumes of the metallic wire means and the natural or artificial fibre means.

According to a third aspect of the present invention, there is provided a method for treating a human or animal subject, comprising the steps of providing a device as described in the first aspect above or an apertured laminar material as described in the second aspect above, and bringing the respective device or material into contact with a portion of the body to be treated, such that said portion of the body is contacted by the apertured laminar material.

According to a fourth aspect of the present invention, there is provided a method of regulating a body or skin temperature of a human or animal subject, comprising the steps of providing a device as described in the first aspect above or an apertured laminar material as described in the second aspect above, and bringing the respective device or material into contact with a portion of the body to be regulated, such that said portion of the body is contacted by or closely adjacent to the apertured laminar material. Embodiments of the present invention will now be more particularly described by way of example and with reference to the figures of the accompanying drawings, in which:

Figure 1 is a schematic representation of an element of copper-containing wire mesh isolated from a device embodying the present invention;

Figure 2 is a graph of bacterial count versus time during a test of the efficacy of a copper-containing wire mesh embodying the present invention;

Figure 3 is a perspective view of a fitted bed sheet embodying the present invention;

Figure 4 is a plan view of an adhesive wound dressing embodying the present invention;

Figure 5 A is a perspective view of a face mask embodying the present invention;

Figure 5B is a scrap cross-section of the face mask shown in Figure 5A;

Figure 6 is a perspective view of an anti-wrinkle eye mask embodying the present invention;

Figure 7 is a schematic plan view of a catheter dressing embodying the present invention;

Figure 8 is a schematic perspective view of a sphygmomanometer cuff embodying the present invention;

Figure 9 is a schematic perspective view of a tourniquet embodying the present invention;

Figure 10 is a schematic frontal elevation of elements of a garment embodying the present invention;

Figure 11 is a plan view of a removable insole for a shoe embodying the present invention; Figure 12 is a schematic elevation of a thread containing copper wire embodying the present invention;

Figure 13 is a schematic perspective view of a mesh embodying the present invention, made with the thread shown in Figure 12;

Figure 14 is a frontal elevation of a baby carrier embodying the present invention, shown unfastened;

Figure 15 is a schematic cross-section of a multilayer fabric containing the mesh shown in Figure 1 or the mesh shown in Figure 13; and

Figure 16 is a schematic cross-section of a hydrogel dressing material embodying the present invention.

Referring now to the Figures and to Figure 1 in particular, the present invention is currently found to be most effective when based on a woven mesh 1 of copper wire, or wire made from an alloy such as bronze having a high copper content. A thin flexible copper sheet could in principle be perforated with a high density of apertures, possibly using laser technology to bore the apertures. However, the cost of production would probably be prohibitive. A non-woven fabric could presumably be made by binding a mat of copper or copper alloy wires, but the treatment necessary to produce a coherent non-woven sheet might interfere with its effectiveness. To produce a flexible, laminar material of high strength, low weight per unit area and having a high density of very fine apertures, a conventional weave having copper/copper alloy wires as both warp and weft appears simplest, easiest, most effective and cheapest to produce. Woven materials, in coarser form, have been produced from brass or steel wire for use as sieves, and a woven mesh of metallic wire is widely used in air filters, so appropriate production methods appear to be available. The woven wire mesh 1 can be defined in terms of several parameters. The number 2 of wires (or holes) in a given length of mesh 1 may be defined, as may the number of holes in a given area of mesh. The average diameter 3 of the wire is also regarded as important, as is the average diameter 4 of a hole. Assuming a regular grid of wires crossing at right angles, as shown, any one of the number 2 of wires/holes, the wire diameter 3 and the hole diameter 4 may be derived from the other two.

A particularly effective wire mesh 1 has been found to be one made from high-purity copper wire, and in particular the grade classified in the UNS system (devised by the Copper Development Association of the USA) as CI 0300. CI 0300 grade copper comprises at least 99.95% by mass metallic copper, with very low levels of phosphorus (0.001 to 0.005% by mass) and extremely low levels of oxygen (it is generally referred to as "oxygen-free", which appears to indicate significantly less than 0.005% oxygen ). It is sufficiently ductile and strong to be drawn out into wire having an average diameter 0.052 millimetres (52 μιη).

The wire mesh 1 tested was woven at approximately 200 wires per linear inch (and hence 200 holes per linear inch) using 0.052 millimetre CI 0300 grade copper wire. This results in a calculated average hole diameter of approximately 0.073 millimetres (73 μπι). The calculated weight per unit area of this mesh 1 is about 300g/m², making it easy to handle. Weight is unlikely to be an issue, even in large sheets. It is possible that the effective surface area of the mesh 1 may also be of importance, for example if its mechanism of action proves to involve dissolution or migration of copper atoms from its surface. Approximate calculations indicate an effective surface area of 2.6 cm for each square centimetre of this mesh. It is strong, flexible and deformable with a degree of resilience.

It is believed that the very high levels of copper are most important to the effectiveness of this mesh 1. Conversely, it is possible that it is the very low levels of impurities that are important, although no particular impurity has yet been identified as harmful to the effectiveness of the mesh. There are also signs (see below) that very small hole diameters 4 may be beneficial, as might be high surface areas. It is believed that the use of even finer, more closely packed wires, and smaller holes, might compensate for slightly lower copper levels (again, see below).

The use of high-purity copper should also ease regulatory approval, in the absence of potentially harmful minor components requiring safety testing.

Substantially pure copper surfaces are known to have beneficial health effects. The use of copper bracelets and the like to treat arthritis is well known. A recent study (Casey et al, Journal of Hospital Infection 2010, vol 74, 72-77) has shown that replacing frequently touched stainless steel surfaces such as push plates with copper counterparts, in a hospital environment, led to significant bacteriostasis and a reduced "reservoir" of harmful bacteria. However, it would be desirable to achieve a bacterial "kill", and the use of solid copper can be limiting, as described above.

Therefore, tests have been carried out on a sample of the woven mesh 1 of CI 0300 grade copper described above, to measure its effect on a standard MRSA culture. EMRSA-16 (NCTC 13143) supplied by the UK Health Protection Agency was maintained on glycerol protect beads (from Fisher Scientific, UK) and stored at -80°C. One such protect bead was added to 15ml brain-heart infusion broth (BHIN, Oxoid, UK) and incubated at 37°C for 16 to 18 hours, to provide the inoculum culture of MRS A. lcm² pieces of the woven copper mesh 1 and of woven cotton fabric (as a reference material) were washed free of existing bacteria by immersion in absolute ethanol and air- drying. These pieces were each inoculated with 20μ1 of the MRSA culture, which was spread over their entire surface and left for a series of predetermined exposure times, ranging up to three hours.

After the set exposure times, bacteria were removed by placing each swatch in a test tube with sterile glass beads (Sigma UK), 5 ml phosphate buffered solution (PBS, Oxoid, UK) and 20 mM ethylene diamine tetracetic acid solution (EDTA; Fisher Scientific, UK) to complex any free copper ions that may be displaced into solution during removal of the bacteria. The test tubes were then vortexed for one minute to knock bacteria from the fabric into the solution.

1 in 10 fold dilutions were then carried out, down to 10^"4 in PBS. 100 μΐ of each dilution was pipetted on to nutrient agar plates (Oxoid, UK) in triplicate, and spread over the agar using L-shaped spreaders. The nutrient agar plates were allowed to dry, inverted and incubated at 37°C for 24 hours. The viable bacteria count was then measured conventionally in c.f.u. (colony-forming units). Statistical analyses were carried out on the results, with PO.001 being selected as the threshold for statistical significance. Figure 2 shows the variation in bacterial count with time for the woven copper mesh 1 (labelled Cu) and for the cotton reference fabric (labelled Ct). The exact inoculum size used was also determined in each case (labelled In). It should be noted that the time scale is linear, but the bacterial count scale is a log scale.

The Cu line indicates a 6 log kill over a period of two hours, which is statistically significant. There is a minor bacterial recovery after two hours. The Ct line shows only a very minor fall in bacterial count.

These results imply a highly effective anti-bacterial impact against MRSA for the woven copper mesh 1. It is postulated that the recovery after two hours might be due to some bacteria trapped in the holes 4 between the wires 3 subsequently re-emerging, having been temporarily inactivated rather than being killed outright. However, the holes 4 have a calculated diameter of 72μηι, while MRSA bacteria are around 2-3 μιη across, so they appear unlikely to be trapped in the holes to a major extent.

Under such conditions, solid copper samples might show bacteriostasis, but such a significant bacterial kill is wholly unexpected. The woven copper mesh is thus not only a more convenient way of employing copper, but also a much more effective one.

Another wire mesh 1 material that shows initial signs of effectiveness is made from bronze wire. The bronze used comprised 93.68% copper, 6.00% tin, 0.26% phosphorus, 0.05% iron, 0.02% lead and 0.002% aluminium. While this has a lower copper content, it may be drawn out into finer wires than pure copper. A wire mesh 1 material was therefore made with 0.03 millimetre (30 μιη) wires, at a density of 600 wires and 600 holes per linear inch. This yields a calculated coverage hole diameter of just over 12 μπι. This mesh 1 has a calculated weight per unit area of just under 300g/m² and a calculated effective surface area of about 4.5 cm² for each square centimetre of mesh.

It is believed that the lower copper content may be compensated for by the greater surface area through which copper may attack the bacteria and/or the finer holes providing more contact time to ensure a permanent kill.

An example of the devices that can be made with such copper-containing meshes 1 is shown in Figure 3. A bedsheet 5 or blanket comprises a zone 6 of the fine copper mesh 1, dimensioned to cover substantially an entire upper surface of a conventional mattress 7. The particular bedsheet 5 shown is a fitted bedsheet 5, with panels 8 of cloth to extend down each side of and beneath the mattress 7. These panels 8 may be provided with a conventional elasticated hem (here concealed beneath the mattress 7) to pull the bedsheet 5 taut across the mattress 7. While the panels 8 could also be of copper mesh 1, this is not necessary, and cloth panels 8 are probably easier to handle.

A non-fitted bedsheet 5 or blanket may also be provided, again most conveniently having a fabric panel 8 extending around some or all of its outer edge, to be tucked securely beneath a mattress 7. Such a sheet 5 may also be used as a top sheet 5, or as one face of a duvet. Its low weight (maybe l-2kg in all) means that it should be perfectly comfortable to lie beneath. One or both faces of a pillowslip may also be made with panels of the copper mesh 1. Sheets with one or more smaller copper mesh 1 zones 6 may also be provided, with the zone or zones 6 disposed to lie adjacent selected parts of the body. A user would lie directly on top of the bedsheet 5/blanket (and/or below a corresponding top sheet). The anti-microbial effects of the fine copper mesh 1 would therefore provided to any part of the user's person in direct contact with the copper mesh 1 (or possibly through lightweight nightwear). Additionally, the benefits found for copper bracelets, etc against arthritis, rheumatism or the like may be provided over the user's whole person, throughout the period that the user rests on the bedsheet 5.

This bedsheet 5 also provides benefits against the microfauna (e.g. bedbugs, dust mites or the like) that tend to inhabit most mattresses and are associated with allergies and asthma in some cases. The copper mesh 1 is likely to be sufficiently fine to act as a physical barrier between the mattress 7 and the user preventing migration of the microfauna from the mattress. It is also likely to have some biocidal effect on the microfauna.

Additionally, the copper mesh 1 is a good conductor of heat, and so should ensure that there are few or no hotspots or cold patches in the bed, before or during use, improving comfort.

The fineness of the copper mesh 1 ensures that the skin "feel" of the sheet 5 is entirely comfortable for the user.

Another device employing the anti-microbial properties of the copper mesh 1 described above is shown in Figure 4. An adhesive wound dressing 9 comprises an elongate strip 10 of elasticated fabric material having a panel 11 of the copper mesh 1 mounted generally centrally to a first face of the strip 10. A remainder of the first face of the strip 10 is coated with an adhesive composition 12, allowing the strip 10 to be securely attached to a skin surface adjacent a wound. A liquid absorbing material may optionally be disposed between the panel 11 and the fabric strip 10. (A range of shapes and sizes of wound dressing may be employed to treat different sizes and shapes of wounds, as for conventional sticking plasters).

The dressing 9 is applied to a patient's skin with the panel 1 1 extending across a wound or the like. The copper mesh 1 will thus provide the anti-microbial effect described above, particularly where there is some exudation of body fluids from the wound into intimate contact with the copper mesh 1. This should aid healing by obviating infection by adventitious micro-organisms and by attacking any infectious micro-organisms already within the wound.

It is possible that such dressings might also help to treat "blind" infections at or near the surface of the body, such as boils and acne. Larger panels 1 1 of the copper mesh 1 might be required where an infection is extensive, such as may occur for acne.

A further application in which initial results are promising is in the treatment of fungal skin conditions, such as that known colloquially as "ringworm" (more correctly tinea). Contact between infected areas of the skin and a panel 11 of the copper mesh 1 for around eight hours each night has resulted in significant reduction in erythema and other symptoms over the course of less than a week.

Where "sealing off of an open wound is not required, and particularly where the panel 1 1 would be periodically removed and replaced, the adhesive 12 backed fabric strip 10 may not be necessary. Instead a panel 1 1 might be mounted to a bandage which would be wrapped or tied around a body part by conventional means. It would also be possible to hold the panel 1 1 in position on a limb by sandwiching it between the part of the limb to be treated and a conventional tubular elastic bandage or muscle/joint strapping.

Panels 1 1 of the copper mesh 1 may also be used in place of copper bracelets and the like to alleviate conditions such as arthritis or rheumatism. A flexible, lightweight panel 11 of the copper mesh 1 may be kept in contact with the relevant portion of the body by any of the above means. The copper mesh 1 should be at least as effective as a solid copper device, and would be easier to keep in the correct position on most parts of the body.

A specialist form of dressing, in which the fine copper mesh 1 described would be particularly beneficial, is shown in Figure 7. A catheter dressing 20 generally comprises a disc of dressing material with a concentric aperture 21 linked to a periphery of the disc by a slit 22. It is used in conjunction with a catheter, intravenous drip or other percutaneous device intended to be left implanted in a patient's body for a prolonged period. The concentric aperture 21 is sized to fit around the catheter, etc, at the point at which it penetrates the skin; the slit 22 allows the catheter dressing 20 to be deformed so that the catheter dressing 20 may be applied around a catheter, etc, that has already been inserted. The catheter dressing 20 is typically held in place with adhesive tape.

In the particular catheter dressing 20 of the present invention, a surface of the disc that will be in contact with the patient's skin is made of the copper mesh 1. The presence of the copper mesh 1 should keep the insertion wound made by the catheter, etc, free from infection, and may also aid healing, including healing of local bruising or other damage caused by insertion of the catheter, etc. Another medical use of the copper mesh 1 is shown in Figure 8. A sphygmomanometer or blood pressure meter 23 comprises an inflatable cuff 24, provided with a connecting tube 25 leading to an inflation pump and a pressure meter (not shown, for simplicity). The cuff 24 comprises an elongate rectangular panel, which is wrapped around a part of the body (an upper arm is conventional for humans), and fastened in place, for example using hook-and- loop repositionable fastening fabric. In use, the cuff 24 is inflated to compress the blood vessels in the arm, and then slowly deflated.

The cuff 24 of a sphygmomanometer 23 may be applied to many different patients each day, with a consequent risk of cross-infection, particularly if one patient has a skin condition. Ideally, the cuff 24 should be disinfected after each use, but in practice, this step appears often to be omitted. Therefore, in the sphygmomanometer 23 of the present invention, at least a skin-contacting surface of the cuff 24 is made up of the fine copper mesh 1. This should at least provide bacteriostasis, avoiding growth of micro-organisms between periodic conventional disinfection procedures. It is believed, however, that the fine copper mesh 1 of the present invention should also provide an active antibacterial, antifungal and even antiviral effect, reducing or eliminating the need for conventional disinfection. The flexibility of the fine copper mesh 1 should avoid discomfort, compared to existing cuffs 24 having polymer surfaces.

An allied use is illustrated in Figure 9. A tourniquet 26 is shown in highly schematic form. A strap 27 or the like is adapted to be wrapped around a limb, and a tightening mechanism 28 is used to tighten the strap 27 until blood flow along the limb is prevented (a range of tightening mechanisms are in use, including inflation systems akin to that used in the sphygmomanometer 23 above, and mechanical arrangements based on windlasses, ratchets, and the like).

There are two main forms of tourniquet 26. Surgical tourniquets are used to reduce or eliminate blood flow to a site of an operation by compressing blood vessels located between the heart and the operation site. Emergency tourniquets are applied to obviate blood flow to a traumatic injury, reducing or eliminating potentially fatal loss of blood. In each case, the tourniquet 26 would be located sufficiently close to an open wound that infection might be at risk. Therefore, in the tourniquet 26 of the present invention, a skin contact surface of the strap 27 is covered with the fine copper mesh 1 , as may be an outer surface of the strap 27.

Figure 5 A shows another use for the fine copper mesh 1 described above. A face mask 13 is configured to extend across a mouth and nose of a wearer, and is provided with ties 14 or elastic straps to extend behind the wearer's head. The face mask 13 can thus be held in position such that the wearer inhales and exhales mainly or entirely through the material of the mask 13 (depending on how good a seal is made between a periphery of the mask 13 and adjacent skin).

The structure of the face mask 13 is shown in Figure 5B. A layer of the copper mesh 1 is co-extensive with a layer 15 of a woven or non-woven fabric material; they are stitched together at least at the periphery of the mask 13, and conveniently may also be tacked together at other points. In use, the copper mesh 1 faces the mouth and nose of the wearer and the layer 15 of fabric faces outwardly. The wearer's breath thus passes in and out through the holes 4 in the copper mesh 1 and through pores in the layer 15 of fabric. Any micro-organisms entrained in inhaled or exhaled gases will tend to be trapped at least temporarily in the mesh 1 or the layer 15 of fabric (which is held in intimate contact with the copper mesh 1, so is affected thereby).

The copper mesh 1 should thus have an anti-microbial effect, inactivating or killing airborne micro-organisms.

The face mask 13 may thus be used to prevent an infected person exhaling infectious micro-organisms (including via coughs and sneezes). Alternatively, it may be used by health professionals to avoid spreading normally low-risk micro-organisms to patients who are already in poor health (especially those with weakened or compromised immune systems). The mask 13 may also be used by a healthy wearer (including but not limited to health professionals) to filter out airborne infectious micro-organisms, to obviate catching colds, influenza and the like.

The face mask 13 could be made without the layer 15 of fabric. However, the fabric will catch and retain moisture (e.g water vapour in the breath or sneeze droplets) better than the mesh 1 of copper wires, and this moisture may assist the action of the copper.

A further use for the fine copper mesh 1 is shown in Figure 6. It is believed that the copper transferred from the mesh 1 to body tissues in contact therewith may help to improve the condition of the skin and subcutaneous tissues in general. In particular, it is believed that prolonged contact may optionally reduce skin wrinkles. An eye mask 16 is therefore provided, comprising a zone 17 of the copper mesh 1 shaped to extend over both eyes and eye sockets. A fabric binding 18 extends around a periphery of the zone 17 of mesh 1 for comfort; a fabric outer layer may optionally also be added to conceal the zone 17 in use. An elastic strap 19 is provided to extend around a back of the wearer's head and hold the zone 17 in contact with the wearer's skin around the eyes. The eye mask 16 is worn at night, much like a traveller's sleep mask, to allow the copper gradually to improve the condition of underlying tissues, reducing or obviating the onset of wrinkles. Similar devices may be tailored to treat wrinkles elsewhere.

Figure 10 shows another use of the fine copper mesh 1 , providing both medical and general health/comfort benefits. Examples of a range of garments 30 are shown, including an undervest 31, underpants 32, socks or stockings 33, gloves 34 or mittens 35, and a ski- mask, hood or balaclava helmet 36. NB: the undervest 31 may have long or short sleeves; the underpants 32 are shown as "long-johns" but may also have a form more like conventional briefs. In each case, the garments 30 are made partially (or better, almost entirely) from the fine copper mesh 1.

As for the bedding shown above, these garments 30 may be used for their effect against micro-organisms and for their heat conductive effects, particularly in extreme climatic conditions.

In very cold conditions, loss of body heat is a major problem, particularly from the extremities, such as the head, hands and feet. Frostbite of toes, fingers and even ears is a major risk for mountaineers and anyone else spending prolonged periods in subzero temperatures. Wearing some or all of the garments 30 made from fine copper mesh 1, next to the skin, or at least very close to the skin, should promote heat flow from the abdomen and torso to the head, hands and/or feet. This will slightly cool the abdomen/torso, but the garments 30 would of course be worn below layers of conventional insulating clothing.

In very hot conditions, when physical exertion cannot be avoided, the main problem will be localised overheating. For example, combat troops in tropical climates can suffer from heat exhaustion, particularly when carrying heavy personal loads and wearing body armour. (To add to the problem, in desert and mountain terrain, very low night-time temperatures can be experienced, as well as very high day-time temperatures).

Wearing some or all of the garments 30 made from fine copper mesh 1, next to or very close to the skin, should promote heat flow away from the hottest parts of the body towards the extremities, where it may more readily be radiated (or sweated) away.

These garments 30 also provide two further potential medical benefits, particularly in military use. When clothing cannot be removed or changed for extended periods, there is a risk of bacterial or fungal infection, particularly around the groin and other particularly warm and sweaty parts of the body. Thus, the underpants 32, even if worn in a short- legged variant, would help to avoid unpleasant infections as a result of their antibacterial/antifungal effects.

Additionally, if military personnel are wounded, a major problem can be infection from debris, including clothing fragments, driven into the wound. If the garments 30 shown are worn, any fine copper mesh 1 therefrom in the wound should at least contain few or no infectious micro-organisms. It may even help to keep the wound free from infection until the wounded individual can be evacuated to receive full medical attention. In any case, the copper mesh 1 of the garments 30, worn next to the skin, should keep the surroundings of a wound substantially free from infection.

Where thermal conduction is most vital, the garments 30 shown could be replaced by a more continuous suit, for example with gloves 34, mittens 35, socks 33 and/ or headpiece/hood/ski mask 36 being permanently connected to the undervest 31 or underpants 32. A single undergarment comprising conjoined undervest 31 and underpants 32 is also possible.

A further use of the fine copper mesh 1 would be as part of a sock 33 worn on its own, to help to cool overheated feet or to spread warmth across the foot in cold conditions as well as having an anti-bacterial and anti-fungal effect to reduce foot-odour and to suppress athlete's foot and the like. Such a sock would be particularly useful when worn with climbing, walking or combat boots, particularly in hot climates or on ice and snow. As well as forming a separate sock 33, the mesh 1 may also be incorporated into the lining of an item of footwear (also frequently termed the "sock"), or into a removable insole 37 (see Figure 1 1) for insertion into existing footwear. These would produce similar benefits.

Another use of the fine copper mesh 1 is the prevention or at least reduction of the transmission of infection from a mother to an infant through the mother's milk. A nipple shield comprising a conformably-shaped cap made from the fine copper mesh 1 is worn over a nipple, optionally with a peripheral ring of low-tack adhesive to hold it in place, or optionally comprising a sufficiently close fit to remain in place. When the infant is nursed, the milk must pass through the holes 4 in the copper mesh 1, and there will be an antimicrobial effect on any harmful micro-organisms entrained in the milk. (It may be necessary to provide an outer layer of a material, such as latex, more closely counterfeiting the correct mouth feel than the copper mesh, to keep the infant happy).

In an allied use, a conventional device for expressing a mother's milk may be provided with a nipple shield or other filtration arrangement using the fine copper mesh 1 described above, in order to obviate infection of the milk reserved for subsequent feeding of the infant.

The fine copper mesh 1 of the present invention may also be of benefit when incorporated into feminine hygiene products. For example, this may provide a defence against infection by the microfungal species Candida albicans.

Another form of woven mesh 54 embodying the present invention is shown in Figures 12 and 13. As mentioned above, if high-purity copper is drawn out into wires of too small a diameter, it becomes too fragile to weave easily. There might also be problems with the durability and strength of a mesh 1 made solely from such wire, even if it could conveniently be woven. As a result, it may be necessary to lower the copper content of the wire in the mesh 1 as a trade-off for finer wires, for example by using bronze, as mentioned above.

Alternatively, it has been found that the weaknesses of the very fine copper wires may be obviated by twisting a high-purity copper wire 52 together with a conventional fibre or thread 53 of similar diameter. The resulting combination thread 51 benefits from the strength and flexibility of the conventional fibre 53, and is almost as easy to handle and to weave. The copper wire 52 is supported by the conventional fibre 53, but since the copper wire 52 and the conventional fibre 53 are of similar diameters and volumes, the copper still comprises 90% or more of the mass of the combination thread 51 and loses relatively little of its active surface area. (Copper has a density of about 8.9g/cm³, while most organic fibres will have a density of between 0.8 and l .Og/cm ).

A typical combination thread 51 comprises a high-purity copper wire strand 52 with a diameter of about 0.035mm (35μπι) and a fine cotton thread 53 also with a diameter of about 0.035mm (35μη ). Twisted together at 33 twists per inch (about 1.3 twists per mm), this produces a combination thread 51 with an effective diameter of about 0.05mm (52μπι). With the copper wire 52 being about 99% pure, this leaves the overall copper content of the combination thread 51 in excess of 90%, with the copper wire 52 itself remaining highly pure and particularly active.

This combination thread 51 may be woven into a combination mesh 54 as shown in Figure 13, with both the warp and the weft comprising the combination thread 51. A wide range of conventional threads 53 have been found to be effective, including cotton, silk and artificial fibres such as polyesters and polyamides. Examples of this combination mesh 54 have been made at 300 and 400 threads per linear inch (i.e. 300 and 400 holes per linear inch, respectively). These yield calculated hole diameters of about 33μπι and 15μ^ηι, respectively. The combination mesh 54 at 300 threads per linear inch has a calculated weight per unit area of about 220g/m² (about 200g/m² as copper) and a calculated effective surface area of about 2.6cm² per cm² of mesh 54. The combination mesh 54 at 400 threads 2 2 per linear inch has a calculated weight per unit area of about 300 g/m (about 270g/m as

2 2

copper) and a calculated effective surface area of about 3.5 cm per cm of mesh 54.

These values for weight of copper per unit area and effective surface area are fully comparable with those of the meshes 1 comprising only copper or bronze wires. The performance of the combination mesh 54 should thus be very similar to that of the meshes 1, and testing to date has confirmed this. (Note: A majority of the testing of the combination mesh 54 has been carried out with a mesh made from a twisted copper/cotton combination thread 51.)

The combination mesh 54 has been tested for anti-bacterial effectiveness against two micro-organisms, S aureus and K pneumoniae, using a plain cotton cloth of similar weave as a control standard. In each case, a standard dose of the respective micro-organism was applied to two samples of the mesh/cloth. One sample was immediately assessed for the number of viable cells present, using routine microbiological assay techniques. The other sample was incubated for 24 hours at 35°C, before being assessed for the number of viable cells present, using the same assay techniques.

In the cotton cloth control standards, the concentration of S aureus increased by about 150- fold over the 24 hour incubation period, while the concentration of K pneumoniae increased by about 100-fold. On the combination mesh 54, there was a 67% reduction in the concentration of S aureus over this period, and a 99.6% reduction in the concentration of K pneumoniae. These effects on these two tough micro-organisms bode well for the effectiveness of the combination mesh 54 in all of the above applications. A further product incorporating the copper mesh 1 or the combination mesh 54 is shown in Figure 14. In less-developed countries (LDCs), a significant cause of death for new-borns and young babies is the difficulty of keeping them warm, particularly for ill and premature babies. Such babies would preferably be kept in an incubator until they are well, but in LDCs incubators are often unavailable (indeed, electrical power to run incubators might be in short supply).

Figure 14 shows a baby carrier 61 that addresses this issue. The baby carrier 61 comprises a pouch structure 62 to hold the baby 63, with a flap 64 that may be folded down over the head of the baby 63 for added protection. A band or sash 65,66 extends to either side of the pouch 62 (this may optionally be detachably mounted to the pouch, to allow the baby 63 to be laid in a bed without being removed from the pouch). The band/sash 65, 66 bears co- operable patches 67 of hook and loop repositionable fastening fabric (or other convenient fastening arrangements) allowing the mother or another adult to wrap the band/sash 65, 66 securely around their body, holding the pouch 62 and baby 63 against their body. At least the face of the pouch 62 that will contact the adult's body contains the mesh 1, 54, and ideally the entire baby carrier 61 has a sheet of the mesh 1, 54 running through it. This will allow rapid transfer of body -heat from the adult's body, through the mesh 1,54, into the pouch 62 and to the baby 63. If the baby 63 overheats, the heat flow will proceed in the other direction. Thus, the body temperature of a baby that is for some reason unable to control its own body temperature, whether for reasons of immaturity or illness, it kept close to that of its mother or other adult carer.

A fabric structure that would be suitable for the baby carrier 61 and other uses is shown in Figure 15. In this multilayer fabric 71 , there is an outer shell 72 of a conventional woven fabric (this may optionally be impervious to water or may include a layer of a breathable waterproof fabric, such as that marketed by WR Gore under the registered trade mark Goretex; alternatively, it may be a simple cotton fabric or the like). Next to the outer shell 72 is a layer of thermally insulating wadding 73, followed by a layer of the copper mesh 1 or the combination mesh 54. In this case, there is also an inner lining 74 of silk, artificial silk or the like, for comfort. This may be omitted where maximum thermal contact with the mesh 1, 54 is most important.

The multilayer fabric 71 may also be used in the manufacture of outer clothing, particularly for outdoor clothing, cold-weather gear and the like. As in the case of the undergarments 30 shown above, the presence of the mesh 54 ensures that the temperature inside the garment remains substantially constant throughout, avoiding localised overheating or cold spots.

Figure 16 shows a development of the dressing 9 shown in Figure 4. A dressing material 81 comprises an outer protective layer 82, which may for example be an impervious plastics film or a breathable material. Adjacent to the outer protective layer is a layer of a hydrogel material 82, which in turn is covered by a sheet of copper mesh 1 or combination mesh 54. This dressing material 81 may be incorporated into a self-adhesive dressing 9 or may be otherwise applied and held to a patient's body 84, over a wound, burn or other lesion.

It is known to use a variety of hydrogel materials to aid the healing of wounds, burns and the like. By interposing a sheet of the mesh 1 , 54 between the hydrogel 83 and the body 84, such that the hydrogel 83 must exude through the holes in the mesh 1, 54, the beneficial healing effect of the copper in the mesh 1, 54 should more readily be transmitted to the patient's body 84, to intercept infectious micro-organisms and to speed healing. As a bonus, the hydrogel 83 should obviate any risk of the mesh 1, 54 adhering to the body 84.

In this particular use, it may be necessary to use more open meshes 1 , 54 with larger holes, in order to allow the hydrogel 83 to flow through the mesh 1, 54 at a sufficient rate. Testing has shown that meshes 1, 54 with no more than 200 wires per linear inch, or preferably no more than 100 wires per linear inch, are needed to allow passage of the hydrogel 84. Clearly, this will lower the amount of copper present per unit area of the mesh 1, 54, so it is likely that appropriate compromises between ease of passage of hydrogel and copper content will be necessary for different uses of the dressing material 81.

Claims

A device to improve the health and/or comfort of a human or animal subject, comprising a zone of a substantially laminar material provided with a plurality of aperture means and comprising a plurality of elongate metallic wire means, each said wire means comprising at least 65% by mass metallic copper, and means to locate said zone of material adjacent a portion of body tissue to be treated.

A device as claimed in claim 1 , wherein said apertured laminar material comprises a mesh of said metallic wire means.

A device as claimed in either claim 1 or claim 2, wherein said apertured laminar material comprises a woven mesh of elongate metallic wire means defining the aperture means.

A device as claimed in any one of the preceding claims, wherein said metallic wire means comprises at least 90% by mass metallic copper.

A device as claimed in any one of the preceding claims, wherein the metallic wire means comprises at least 99% by mass metallic copper.

A device as claimed in any one of the preceding claims, wherein said metallic wire means has an average diameter of less than 0.2mm.

7. A device as claimed in any one of the preceding claims, wherein said metallic wire means has an average diameter of between 0.02 and 0.06mm.

8. A device as claimed in any one of the preceding claims, wherein said apertured laminar material is provided with a plurality of aperture means having an average diameter of less than 0.2mm.

9. A device as claimed in any one of the preceding claims, wherein said aperture means have an average diameter of less than 75 micrometers.

10. A device as claimed in any one of the preceding claims, wherein each said metallic wire means is twisted together with elongate natural or artificial polymeric fibre means to form elongate composite fibre means.

1 1. A device as claimed in claim 10, wherein the metallic wire means and the natural or artificial fibre means have approximately equal diameters.

12. A device as claimed in any one of the preceding claims, comprising sheet means adapted to be mounted to bed means.

13. A device as claimed in claim 12, wherein the zone of apertured laminar material of the device is dimensioned to extend across substantially an entire upper, in use, surface of mattress means of the bed means.

14. A device as claimed in any one of claims 1 to 11 , comprising dressing means for a wound or infected area of body tissue.

15. A device as claimed in claim 14, wherein the dressing means comprises laminar backing means having the zone of apertured laminar material mounted to one face thereof, said laminar backing means comprising or being provided with means so to secure the dressing means to a human or animal body that the zone of apertured laminar material is in contact with wounded and/or infected tissue.

16. A device as claimed in claim 15, wherein the laminar backing means is provided with adhesive means adapted to secure the dressing means temporarily to a body surface adjacent the wounded and/or infected tissue.

17. A device as claimed in claim 15, wherein the fabric backing means is adapted to be wrapped around a part of the human or animal body.

18. A device as claimed in any one of claims 15 to 17, further comprising a layer of gel material disposed between the laminar backing material and the apertured laminar material.

19. A device as claimed in any one of claims 1 to 1 1 , comprising means to improve a cosmetic appearance of a skin surface, said skin surface optionally comprising wrinkles, scars and/or other surface lesions.

20. A device as claimed in claim 19, comprising supporting means wearable around a part of the body₂ having the zone of apertured laminar material so mounted thereto as to be maintainble in contact with the lesions to be treated.

21. A device as claimed in any one of claims 1 to 11, comprising breathing mask means wearable over a mouth and nose of a human or animal..

22. A device as claimed in claim 21, wherein the breathing mask means comprises a zone of porous fabric material at least co-extensive with the zone of apertured laminar material, and disposed externally of the zone of apertured laminar material in use.

23. A device as claimed in any one of claims 1 to 11 , comprising a nipple shield adapted to obviate transfer of infection from a nursing mother in her milk.

24. A device as claimed in any one of claims 1 to 1 1, comprising a medical device contactable in use with a skin surface of a subject, wherein a skin-contacting surface of the device comprises said zone of said apertured laminar material.

25. A device as claimed in any one of claims 1 to 1 1, comprising garment means.

26. A device as claimed in claim 25, adapted to be worn in contact with or adjacent a body surface.

A device as claimed in claim 25, comprising an outer garment.

28. A device as claimed in any one of claims 1 to 1 1 , comprising a feminine hygiene product.

29. A device to improve the health and/or comfort of a human or animal subject, substantially as described herein with reference to the Figures of the accompanying drawings.

30. An apertured laminar material adapted for use in a device as claimed in any one of the preceding claims, comprising a woven mesh of metallic wire means, said wire means comprising at least 90% by mass metallic copper.

31. An apertured laminar material as claimed in claim 30, wherein said wire means comprises at least 99% by mass metallic copper.

32. An apertured laminar material as claimed in either claim 30 or claim 31 , wherein said wire means comprises at least 99.9% by mass metallic copper.

33. An apertured laminar material as claimed in any one of claims 30 to 32, wherein the metallic wire means define aperture means of the material therebetween.

34. An apertured laminar material as claimed in any one of claims 30 to 33, wherein each said metallic wire means is twisted together with elongate natural or artificial polymeric fibre means to form elongate composite fibre means.

35 An apertured laminar material as claimed in claim 34, wherein the composite fibre means are formed into said woven mesh.

36. An apertured laminar material substantially as described herein with reference to Figures 1 , 2, 12 and 13 of the accompanying drawings.

37. A method of treating a human or animal subject, comprising the steps of providing a device as claimed in any one of claims 1 to 29, or an apertured laminar material as claimed in any one of claims 30 to 36, and applying the respective device or material to a portion of the body to be treated that said portion of the body is contacted by the apertured laminar material.

38. A method of regulating a body or skin temperature of a human or animal subject, comprising the steps of providing a device as claimed in any one of claims 1 to 29, or an apertured laminar material as claimed in any one of claims 30 to 36, and bringing the respective device or material into contact with a portion of the body to be regulated, such that said portion of the body is contacted by or closely adjacent the apertured laminar material.