Composition for use in the acidification of a medium

Abstract

The present invention relates to a composition comprising superabsorbent fibres based on polyacrylic acid, and / or the salts thereof, for use in the acidification of a medium. The present invention can be used in the biomedical field, such as for wound treatment, and in the food, agricultural and cosmetic fields.

Description

Description Title: Composition for use in the acidification of a medium

[0001] The present invention relates to a composition for use in the acidification of a medium.

[0002] The present invention may find applications in the biomedical field, such as wound treatment, in the food, agricultural and cosmetic fields. Context of the invention

[0003] Most chronic wounds have an alkaline pH, whereas a shift to an acidic pH is preferable for healing. Furthermore, many microorganisms struggle to survive at lower pH levels due to reduced gene expression, decreased enzyme activity, and loss of the membrane pH gradient.

[0004] Many species of bacteria and yeasts commonly associated with wound infection tend to thrive in neutral or alkaline conditions. When microorganisms are in environments with a less-than-optimal growth pH, ​​they experience pH stress, which ultimately leads to intracellular acidification. Therefore, the inclusion of an acid, organic or inorganic, to lower the pH of the exudate creates an inhospitable environment for microorganisms, resulting in superior performance compared to using a silver ion source.

[0005] Indeed, the normal pH of the skin is between 4.1 and 5.8, with healthy skin having a pH below 5.0. When an injury occurs, the skin's pH level changes, leading to various impacts on the healing process. The pH of exposed tissue is initially neutral due to disruption of the naturally acidic skin barrier and microcirculation. This less acidic environment persists in chronic wounds as part of the chronicity process, drawing oxygen into the tissues, a phenomenon known as the Bohr effect.

[0006] pH changes can also be caused by bacterial activity. Bacterial enzyme activity, such as urease produced by bacteria like P. mirabilis and P. aeruginosa, can release ammonia, raising pH levels. This environment can damage tissues and further reduce tissue oxygenation, potentially leading to complications in the healing process.

[0007] Furthermore, the alkaline environment of the wound can alter the regulation of metalloproteinase proteolysis. Wound alkalinity has a significant impact on its healing potential. Alkalinity increases the risk of non-healing by 8%. For example, chronic venous ulcers are characterized by an alkaline pH between 7.9 and 8.7, as well as the presence of bacteria such as Staphylococcus aureus and Plasmodium aeruginosa. Interestingly, no direct association was found between the bacterial profile and pH levels in these ulcers, although infection does indeed increase the wound pH. Moreover, for every one-unit change in pH, a corresponding change in wound size of approximately 116.05 mm³ can be expected. 2 .

[0008] Wound treatment has already been described, including the treatment of ulcers. For example, patent FR3066390 describes the use of oligosaccharide compounds to treat foot ulcers in diabetic patients with arteriopathic disease; Edmonds et al. also describe the use of sucrose octasulfate (TLC-NOSF) for the treatment of foot ulcers in neuro-ischemic diabetics (Lancet Diabetes Endocrinol 2017); and Lazaro-Martinez et al. describe the use of a TLC-NOSF dressing for the treatment of foot ulcers in neuro-ischemic diabetics (Journal of Wound Care, Volume 28, June 2019).

[0009] Also, in a study by Strohal et al. (Adv Skin Wound Care. 2018 Apr;31(4):163-171. doi: 10.1097 / 01.ASW.0000530687.23867. bd), a group of patients with heavily colonized chronic leg ulcers, including venous leg ulcers and other etiologies, had an initially alkaline and elevated wound bed pH of 9.23 ± 0.61. As the researchers administered antimicrobial treatment, the wound bed pH and bacterial load gradually decreased, which is consistent with the results of other studies.

[0010] Wound treatment can be complex, especially for chronic wounds. Therefore, there is a constant need for new wound therapies, particularly for chronic wounds. Specifically, there is a need to reduce the alkaline environment of a wound, ideally towards a slightly acidic pH that promotes healing.

[0011] The present invention is based on the results of the Inventors which illustrate that superabsorbent fibers based on polyacrylic acid, and / or its salts, allow the acidification of a medium.

[0012] The present invention thus aims to provide a new means of acidifying a medium, particularly in the context of the treatment of chronic wounds. Description of the invention

[0013] According to a first aspect, the invention relates to a composition comprising superabsorbent fibers based on polyacrylic acid, and / or its salts, for use in acidifying a medium. More particularly, the invention relates to a composition comprising superabsorbent fibers based on polyacrylic acid, and / or its salts, for use in acidifying a medium in the treatment of wounds, in particular cavity wounds, venous ulcers, diabetic foot ulcers, and / or pressure ulcers. In other words, the invention relates to a composition for use in wound treatment to acidify the medium, i.e., the wound environment.

[0014] According to a second aspect, the invention also relates to a dressing or compress comprising a composition including superabsorbent fibers based on polyacrylic acid, and / or its salts, for acidifying an environment during the treatment of wounds, in particular cavity wounds, venous ulcers, diabetic foot ulcers and / or pressure ulcers.

[0015] According to a third aspect, the invention also relates to the use in a food application of a composition comprising superabsorbent fibers based on polyacrylic acid, and / or its salts, for the acidification of a medium.

[0016] According to a fourth aspect, the invention also relates to the use in an agricultural application of a composition comprising superabsorbent fibers based on polyacrylic acid, and / or its salts, for the acidification of a medium.

[0017] According to a fifth aspect, the invention finally relates to the use in a cosmetic application of a composition comprising superabsorbent fibers based on polyacrylic acid, and / or its salts, for the acidification of a medium. Detailed description of the invention

[0018] The invention relates to the use of a composition comprising superabsorbent fibers in various therapeutic and non-therapeutic fields.

[0019] The present invention relates to a composition comprising superabsorbent fibers containing at least polyacrylic acid, and / or its salts, for use in the acidification of a medium. The present invention also relates to the use of said fibers in food, agricultural, or cosmetic applications for the acidification of a medium.

[0020] By "acidification of the medium," we mean a decrease in pH in the environment or microenvironment of the fiber. Preferably, we mean a decrease in the alkalinity of a medium, and preferably the acidification of a medium having a pH greater than 6, preferably greater than 7, greater than 8, and even more preferably greater than 8.5.

[0021] The term "superabsorbent" refers to fibers which have a very high capacity for absorbing liquids, preferably greater than or equal to 10 g of water (or saline solution such as physiological serum) per gram, preferably even greater than 20 g of water per gram, and preferably even greater than 30 g of water per gram.

[0022] The term "polyacrylic acid-based fibers" refers to fibers formed from (co)polymers derived from acrylic acid and / or substituted derivatives of acrylic acid and / or salts of acrylic acid. The polymers may be cross-linked or non-cross-linked. Polyacrylic acid and / or at least one of its salts is used in the superabsorbent fibers according to the invention. The superabsorbent fibers according to the invention may thus comprise: (i) fibres formed solely from acrylic acid polymers and / or its salts, (ii) fibres formed from acrylic acid polymers, and / or its salts, with other types of acrylic monomers or polymers, and / or their salts, such as methacrylic acid polymers and / or methylacrylate, and / or (iii) fibres formed from acrylic acid polymers, and / or its salts, with non-acrylic acid-based polymers, ...

[0023] According to one embodiment of the invention, the superabsorbent fibers based on polyacrylic acid, and / or its salts, can be in the form of an alkali metal salt (for example sodium salt or potassium salt) or in the form of an ammonium salt.

[0024] The superabsorbent fibers according to the invention can be bicomponent, i.e., comprising or made up of two different materials. These materials can be arranged in a side-by-side configuration or a core / shell configuration, preferably in a core / shell configuration.

[0025] The first material, typically intended to form at least an external part of the fiber, must be capable of forming a gel upon absorption of a liquid. It will advantageously be formed of one or more crosslinked and / or partially crosslinked polymers, such as, in particular, acrylic acid polymers and / or polymers of acrylic acid salts, notably sodium or ammonium acrylate.

[0026] The second material, preferably intended to form the core of the superabsorbent fibers, will advantageously be non-gelling and compatible with the first material to ensure the stability of the fiber after gel formation by the first material. It can be made of any type of polymer stable in aqueous media and compatible with the first material to produce a stable two-component fiber. Examples of suitable polymers include polyacrylonitrile, polyethylene glycol, polyvinylpyrrolidone, polyacrylamide, and certain cellulose ethers. Preferably, the second material is made of polyacrylonitrile.

[0027] According to one embodiment, the first material, for example intended to form an external part of the fiber, preferably the bark, must be capable of forming a gel with wound exudates and will advantageously be formed of one or more cross-linked and / or partially cross-linked polymers, such as, in particular, acrylic acid polymers and / or polymers of acrylic acid salts, especially sodium or ammonium acrylate. Preferably, the first material is formed of ammonium acrylate.

[0028] In one embodiment, the second material, which preferably forms the core of the superabsorbent fibers, is preferably non-gelling and compatible with the first material to ensure the stability of the fiber after gel formation by the first material. It can be made of any type of polymer stable in aqueous media and compatible with the core material to produce a stable two-component fiber. Examples of suitable polymers include polyacrylonitrile, polyethylene glycol, polyvinylpyrrolidone, polyacrylamide, and certain cellulose ethers. Preferably, the second material is made of polyacrylonitrile.

[0029] According to one embodiment, the superabsorbent fibers according to the invention are of the core / shell type with a core made of polyacrylonitrile and a shell based on polyacrylic acid, and / or its salts.

[0030] Typically, the length of the superabsorbent fibers according to the invention can be in the range of 10 to 100 mm, preferably from 25 to 75 mm.

[0031] According to a preferred embodiment, the superabsorbent fibers according to the invention have a count between 2 and 6 Dtex.

[0032] For example, the fibers according to the invention could be the Lanseal™ superabsorbent fibers from Toyobo / Japan Exlan (JE) or fibers marketed by Technical Absorbents (TA), such as SAF™ fibers. Lanseal™ fibers are composed of a polyacrylonitrile core and a bark based on acrylic acid and / or its salts. SAF™ fibers, on the other hand, are formed from a cross-linked polymer of acrylic acid, methyl acrylate, and a small amount of Special Acrylate / Methacrylate Monomer (SAMM, 'Special Acrylate / Methacrylate Monomer') in which the acrylic acid is partially neutralized to sodium acrylic acid salt (AANa). These SAF™ fibers are available in various fiber lengths, linear densities, and cross-linking levels to achieve different absorption capacities.

[0033] The superabsorbent fibers according to the invention can be used alone or in combination with non-absorbent fibers. According to one embodiment of the invention, the composition may comprise a mixture of superabsorbent fibers and non-absorbent fibers.

[0034] Non-absorbent fibers can be thermally bonded fibers, non-thermally bonded fibers, or a mixture of thermally bonded and non-thermally bonded fibers. Preferably, non-absorbent fibers are thermally bonded fibers or a mixture of thermally bonded and non-thermally bonded fibers.

[0035] According to one embodiment of the invention, the composition may comprise a mixture of superabsorbent fibers and non-absorbent thermally bonding fibers.

[0036] According to one embodiment of the invention, the non-absorbent fibers may comprise or be made of a single material. According to another embodiment, the non-absorbent fibers may be bicomponent, i.e., comprise or be made of two different materials.

[0037] According to one embodiment of the invention, the non-absorbent fibers are thermally bonding fibers, that is to say, they comprise or are made up of at least one thermoplastic material such as, for example, polyethylene, polypropylene, or even a low melting point polyester.

[0038] According to one embodiment of the invention, the non-absorbent thermally bonding fibers can be single-component, that is to say, they comprise or are made of a single material, such as a thermoplastic material such as, for example, polyethylene, polypropylene or low-melting-point polyester.

[0039] According to another embodiment, non-absorbent thermally bonding fibers can be bicomponent, i.e. comprise or be made up of two different materials.

[0040] Preferably, non-absorbent thermobonding fibers are bicomponent, particularly in a side-by-side or core / bark type configuration, more particularly of the core / bark type.

[0041] According to one embodiment of the invention, the two-component, non-absorbent, thermally bonded fibers are of the core / shell type, said core being made of polyethylene terephthalate or polypropylene, preferably polyethylene terephthalate, and said shell being made of polyethylene. According to a particularly preferred embodiment, the two-component, non-absorbent, thermally bonded fibers are of the polyethylene terephthalate / polyethylene or polypropylene / polyethylene type.

[0042] Typically, the length of non-absorbent fibers can be in the range of 10 to 100 mm, preferably 25 to 75 mm.

[0043] In general, the composition according to the invention will be obtained from a mixture incorporating more than 50% by weight, preferably more than 60% by weight, of superabsorbent fibers.

[0044] The mass ratio between superabsorbent and nonabsorbent fibers, preferably thermally bonded, can be between 20 / 80 and 80 / 20, preferably between 60 / 40 and 80 / 20, and even more preferably between 70 / 30 and 80 / 20. A mass ratio between superabsorbent and nonabsorbent fibers within these ranges advantageously yields very good results in acidifying a medium, particularly when the nonabsorbent fibers are thermally bonded or a mixture of thermally bonded and non-thermally bonded fibers. The thermally bonded fibers are preferably of the core / bark type, and the fiber mixture is preferably a blend of 15% thermally bonded nonabsorbent fibers and 15% non-thermally bonded nonabsorbent fibers. Excellent results were obtained using a mixture comprising a mass ratio of approximately 70 / 30 superabsorbent and non-absorbent thermally bonding fibers.The expression "approximately 70 / 30" means a ratio that is exactly the same as 70 / 30, as well as a ratio that is slightly lower or higher than 70 / 30, such as 69 / 31 or 71 / 29.

[0045] According to one embodiment of the invention, superabsorbent and non-absorbent fibers, the non-absorbent fibers preferably being thermally bonded, can be assembled into a nonwoven fabric, either by dry or aerodynamic means. Typically, the resulting nonwoven fabric can then be bonded using various techniques known to those skilled in the art.

[0046] This nonwoven fabric can be bonded using technologies such as needle punching, thermal bonding, or, preferably, needle punching and thermal bonding. According to one embodiment of the invention, all the fibers can thus be thermally bonded and / or needle-punched, preferably thermally bonded and needle-punched. The composition for its use according to the invention can thus be characterized in that all the fibers are thermally bonded and / or needle-punched.

[0047] According to one embodiment of the invention, the superabsorbent and non-absorbent fibers, the non-absorbent fibers preferably being thermally bonded, can be knitted or woven. The composition for its use according to the invention can thus be characterized in that all the fibers are knitted or woven.

[0048] According to a preferred embodiment, superabsorbent and nonabsorbent thermally bonded fibers are assembled into a nonwoven fabric by dry process, and the assembled nonwoven fabric is then bonded by needle punching and thermal bonding.

[0049] The needle-punching operation notably strengthens the mechanical properties of the nonwoven fabric. In a preferred embodiment, the needle-punching operation aims to interlock the nonwoven fabric obtained by assembling a mixture comprising superabsorbent fibers and non-absorbent fibers, preferably thermally bonding fibers.

[0050] The thermal bonding process can be described as follows. The nonwoven fabric obtained by blending a mixture of superabsorbent and nonabsorbent thermally bonded fibers is heated. Those skilled in the art know how to select the heating temperature according to the fiber materials in the mixture. This heating activates the nonabsorbent thermally bonded fibers, either by melting their outer layer in the case of two-component core / outer layer fibers, or by melting their single-component material in the case of single-component fibers. The molten polymer material spreads over both types of fibers and, upon cooling, binds them together, regardless of their initial composition. The nonabsorbent thermally bonded fibers allow all the fibers of the nonwoven fabric to be thermally bonded. Advantageously, the thermal bonding process improves the tear resistance of the nonwoven fabric after absorption by creating anchor points between the fibers.It is necessary to reinforce the cohesion of the non-woven fabric to allow the removal of the used composition without tearing it.

[0051] According to one embodiment of the invention, the fiber assembly will be carried out under conditions allowing the production of a non-woven fabric with a thickness between 0.6 and 3 mm, preferably 2 mm, and a basis weight between 40 and 400 g / m2, preferably in the range of 50 to 200 g / m2.

[0052] According to one embodiment of the invention, the composition comprises a mixture consisting of 70% superabsorbent core / shell fibers of the ammonium polyacrylate / polyacrylonitrile type and 30% non-absorbent thermally bonded core / shell fibers of the polyethylene terephthalate / polyethylene type, and the whole of said fibers is thermally bonded and needle-punched.

[0053] The composition can, for example, be manufactured according to the process described in document GB 2 401 879.

[0054] The composition according to the invention can be incorporated into a dressing, alone or in combination with another dressing, and / or a backing, i.e., a fluid-impermeable layer. A contact layer partially covering the face of the composition intended to come into contact with the wound can also be provided. This layer may include openings allowing the passage of wound exudate. This contact layer may be formed of a composition comprising an elastomeric matrix and hydrocolloids.

[0055] For the purposes of this application, the term "dressing" means all types of dressings that can be used for the treatment of wounds.

[0056] The invention thus relates to a dressing or compress comprising a composition including superabsorbent fibers based on polyacrylic acid, and / or its salts, for its use in the acidification of a medium in the treatment of wounds, in particular cavity wounds, venous ulcers, diabetic foot ulcers and / or pressure ulcers.

[0057] In general, the composition according to the invention can be used alone or in combination with one (or more) other active substance(s).

[0058] In general, the active ingredients are chosen from among antibacterials, antiseptics, antivirals, antifungals, pain relievers, anti-inflammatories, healing promoters, moisturizing agents, depigmenting agents, keratolytic agents, restructuring agents, anesthetics and their mixtures.

[0059] As examples, the assets are chosen from: - healing agents such as retinol, vitamin A, vitamin E, N-Acetyl Hydroxyproline, Centella Asiatica extracts, papain, silicone, essential oils of thyme, niaouli, rosemary, sage, hyaluronic acid, potassium sucrose octasulfate, sucralfate, allantoin, metformin; - antibacterial agents such as silver salts or complexes (such as silver sulfates, silver nitrates, silver sulfonamides, silver chloride, silver sulfadiazine or silver-based zeolites), zinc or copper salts, metronidazole, neomycin, penicillins, clavulanic acid, tetracyclines, mynocycline, chlorotetracycline, aminoglycosides, amikacin, gentamicin, probiotics; - antiseptics such as chlorhexidine, trichlosan, biguanide, polyhexamethylene biguanide, hexamidine, thymol, lugol, povidone iodine, benzalkonium and benzethonium chloride, quaternary ammonium compounds; - painkillers such as paracetamol, codeine, dextropropoxyphene, tramadol, morphine and its derivatives, corticosteroids and their derivatives; - local anesthetics such as lidocaine, benzocaine, dibucaine, pramoxine hydrochloride, bupivacaine, mepivacaine, prilocaine, etidocaine; - Anti-inflammatory drugs such as non-steroidal anti-inflammatory drugs (NSAIDs), aspirin or acetylsalicylic acid, ibuprofen, ketoprofen, flurbiprofen, diclofenac, aceclophenac, ketorolac, meloxicam, piroxicam, tenoxicam, naproxen, indomethacin, naproxcinod, nimesulid, celecoxib, etoricoxib, parecoxib, rofecoxib, valdecoxib, phenylbutazone, niflumic acid, mefenamic acid.

[0060] Of course, the composition according to the invention may also include one or more other compounds known for their action in the cleansing phase, such as: - enzymes; - urea.

[0061] Other substances that promote healing, such as growth factors, can be incorporated.

[0062] The composition according to the invention may also include fibers with antibacterial properties. For example, these fibers may incorporate a metal (silver, copper, zinc) or another antibacterial agent. In the case of a metal, these fibers can be obtained in different ways: by incorporating the metal into the polymer matrix during extrusion (PP, PET, PA) or by applying the metal to the spin finish during the spinning process (acrylic, viscose). The metal used to manufacture these fibers may be in the form of salts, zeolites, ceramics, or nanoparticles.

[0063] The elastomeric composition containing hydrocolloids that can be used for the manufacture of dressings according to the invention comprises an elastomeric matrix in which hydrocolloids are preferably dispersed homogeneously.

[0064] The contact layer of the dressing of the invention advantageously prevents it from adhering to the wound and avoids any pain upon removal of the dressing. By maintaining a moist environment on the wound surface while preventing contact with the absorbent pad laden with exudate, it improves healing. The incorporation of hydrocolloids gives the elastomeric composition a hydrophilic character and promotes the delivery of active ingredients that can aid in wound treatment. Such elastomeric matrices are described in the following patents and patent applications: FR 2759379, EP 2 793 773, EP 2874670, WO 2017 / 017386, EP 3452 117, EP 3 651 707.

[0065] Description of the Figure

[0066] Figure 1. Figure 1 shows the evolution of the pH of wounds treated either with the dressing according to the invention UrgoClean® Ag, or with a non-adherent NAD dressing (Curad), not according to the invention, as a function of time in days.

[0067] The invention is illustrated by the following examples.

[0068] Examples

[0069] Examples 1 to 5: pH measurement on different superabsorbent non-woven substrates

[0070] Material :

[0071] The DUAL MPA 580 cutometer (BIOM-07) and its associated PH905 Skin pH meter probe (BIOM-007 / 06) were used. The associated software is MPA CTpIus.

[0072] The pH meter probe is a contact probe.

[0073] Measures :

[0074] The measurements are taken in the laboratory at 21 °C Z65% RH.

[0075] The measurements are taken with a probe having a flat head to optimally measure the surface of our materials. The pH is expressed to two decimal places.

[0076] The probe is calibrated every day it is used. The probe contains a microprocessor that stores all the calibration data.

[0077] The measurements taken are continuous, meaning each measurement lasts 20 seconds. Continuous measurement allows us to see how the pH changes over time, and this is displayed as a curve using the MPA CTpius software. For each sample, three continuous 20-second measurements are taken. For each measurement, the average is calculated over the 20-second measurement period. Then, for the experiments, the average of three measurements is calculated.

[0078] Operating procedure:

[0079] For this study, the pH was measured on various non-woven fabrics from Freudenberg and Technical Absorbents Ltd., both dry and wet, in different buffer solutions to determine if the non-woven fabric's pH changes upon contact with buffer solutions ranging from pH 7 to 10. The pH of the buffer solutions was measured to validate their values. The pH of the different gauze pads in their dry state was also measured. A drop of water was placed on the pH probe to ensure good contact between the non-woven fabric and the probe.

[0080] The pH of sterile compresses (viscose / PET) is measured and used as a control

[0081] The pH of the different non-woven fabrics that have been in contact with the different buffer solutions is measured. For this purpose, samples of approximately 20 cm 2are immersed in a beaker containing a buffer solution, then left to soak for 30 seconds to 1 minute. The samples are drained and then placed to measure their pH.

[0082] Products used:

[0083] Example 1: Compress made from viscose and sterile polyethylene terephthalate, marketed by Laboratoires Urgo under the trade name "Sterile Non-woven Compresses" -Control.

[0084] Example 2: 185 g / m² non-woven fabric 2 marketed by Freudenberg under the name M1516 WPRC, composed of 70% superabsorbent core / shell fibers of the ammonium polyacrylate / polyacrylonitrile type and 30% non-absorbent thermally bonding core / shell fibers of the polyethylene terephthalate / polyethylene type.

[0085] Example 3: 185 g / m² non-woven fabric 2marketed by Freudenberg under the name M1516 WPRC, coated with the elastomeric mass whose composition is described in the following Table 1:

[0086] [Table 1] Quantity Constituent Trade name (as a percentage by weight relative to total weight) Pioneer 2076P marketed Plasticizing oil 32.38 by Hansen & Rosenthal CMC Blanose 7H4XF PH Carbo xymethylcellulose 14.00 marketed by Ashland Poly(styrene-ethylene-butylene-Kraton G 1654 ES) 6.00 styrene) marketed by Kraton Irganox 1010 commercially available Phenolic antioxidants 0.12 by BASF Copolymer of a salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1 acid - Sepineo Derm, commercially available 5.00 propanesulfonic acid and ester 2- by SEPPIC hydroxyethyl of propenoic acid Escorez 5380 hydrocarbon resin, commercially available 35.00 cycloaliphatic by ExxonMobile Chemical

[0087] This elastomeric mass is obtained by mixing the plasticizing oil and caroboxymethylcellulose in a mixer preheated to 90°C. After 30 minutes, the elastomer and antioxidant are added. The mixer's temperature is then raised to 130°C. One-third of the resin is added, and 20 minutes later, the remaining two-thirds are added. Once the mixture is homogeneous, the copolymer is added. The mixer is drained 20 minutes after this final addition.

[0088] Example 4: Oasis Compress Type 2356 marketed by Technical Absorbents Ltd, thermally bonded nonwoven fabric composed of 70% superabsorbent sodium acrylate fibers, 15% non-absorbent polyethylene terephthalate (PET) fibers and 15% thermally bonded non-absorbent polypropylene fibers (138 g / m²) 2 (1.91 mm thick)

[0089] Example 5: Airlaid 2091 compress marketed by Technical Absorbents Ltd, thermally bonded nonwoven fabric composed of superabsorbent sodium acrylate fibers, cellulose pulp (fluff pulp) and thermally bonded bicomponent fibers (180 g / m²) 2 (2 mm thick).

[0090] Results: The average pH is calculated from the three measurements, which are themselves averaged over the 20-second measurement period. The pH measurement results for the different non-woven substrates described above (examples 1-5) are presented in Table 2. The abbreviation "NC" means "not calculated" and designates a measurement that was not performed.

[0091] [Table 2] stamp stamp stamp Examples of pH 10 buffer pH 7 pH 8 pH 9 Example 1 compress 7.05 7.96 8.90 9.82 dried Example 2 M1516 6.15 6.70 7.20 7.54 Example 3 BC708 6.44 7.20 7.75 7.31 Example 4 TAL 2356 6.52 7.25 7.65 NC Example 5 Airlaid TAL 6.70 7.27 8.03 NC 2091

[0092] These results therefore show that a composition including superabsorbent fibers based on polyacrylic acid or its salts allows the acidification of a medium.

[0093] Example 6

[0094] A porcine study was conducted to evaluate debridement and the progression of wound healing of burns treated daily with various debriding agents.

[0095] Twenty (20) full-thickness burns, 2 cm in diameter, were created on the back of a pig using heated brass rods. Initial treatments took place on Day 1 (approximately 24 hours after the creation of the burns): a sterile saline-impregnated compress was applied to each wound for 5 minutes, followed by treatment with a dressing according to the invention, UrgoClean® Ag (UCAg), or a non-adherent dressing (NAD, Curad), not according to the invention.

[0096] The treatments were repeated every 24 hours, and the pH of the wounds was measured daily before retreatment using the Hanna Instruments skin pH meter (see Figure 1).

[0097] According to the Inventors' hypothesis, the pH variations observed between J1 and J3 with the UCAg dressing according to the invention could be explained by the variations related to the volume of exudate between J2 and J3.

[0098] This study shows that the dressing which contains acidifying fibers coated with an elastomeric matrix which contains silver (UCAg) allows for acidification of the wound (burn).

[0099] This study shows that the dressing according to the invention allows for acidification of the wound.

Claims

Demands

1. Composition comprising superabsorbent fibres based on polyacrylic acid, and / or its salts, for its use in the acidification of a medium.

2. Composition for its use according to claim 1, in the treatment of wounds, in particular cavity wounds, venous ulcers, diabetic foot ulcers and / or pressure ulcers.

3. Composition for its use according to claim 1 or 2, characterized in that the superabsorbent fibers based on polyacrylic acid are in the form of ammonium salt or in the form of alkali metal salt.

4. Composition for use according to any one of the preceding claims, characterized in that the composition comprises a mixture of superabsorbent and nonabsorbent fibers.

5. Composition for its use according to claim 4, characterized in that the non-absorbent fibers are thermally bonding.

6. Composition for its use according to claim 5, characterized in that the non-absorbent thermally bonding fibers are two-component of the side-by-side type or of the core / bark type.

7. Composition for its use according to claim 6, characterized in that said bicomponent fibers are of the core / shell type, said core being of polyethylene terephthalate, or of polypropylene, and said shell being of polyethylene, more particularly the non-absorbent bicomponent fibers are of the polyethylene terephthalate / polyethylene or polypropylene / polyethylene type.

8. Composition for use according to any one of the preceding claims, characterized in that the length of the superabsorbent and / or nonabsorbent fibers is in the range of 10 to 100 mm, preferably 25 to 75 mm.

9. Composition for use according to any one of the preceding claims, characterized in that the composition according to the invention is obtained from a mixture incorporating more than 50% by weight, preferably more than 60% by weight, of superabsorbent fibers.

10. Composition for use according to any one of claims 4 to 8, characterized in that the mass ratio between superabsorbent and nonabsorbent fibers, preferably thermally bonding, is between 20 / 80 and 80 / 20, preferably between 60 / 40 and 80 / 20, more preferably about 70 / 30.

11. Dressing or compress comprising a composition including superabsorbent fibers based on polyacrylic acid, and / or its salts, for acidifying an environment during the treatment of wounds, in particular cavity wounds, venous ulcers, diabetic foot ulcers and / or pressure ulcers.

Images