WO2020079330A1

WO2020079330A1 - Composite protecting device that fits closely onto a wound

Info

Publication number: WO2020079330A1
Application number: PCT/FR2019/000171
Authority: WO
Inventors: Jean-François VAN CLEEF
Original assignee: Van Cleef Jean Francois
Priority date: 2018-10-16
Filing date: 2019-10-14
Publication date: 2020-04-23
Also published as: FR3087126A1

Abstract

The invention relates to a composite core/shell-type protecting device that fits closely onto a wound, comprising an envelope that encloses at least one shear thickening material, said envelope consisting of a film that can be stretched by at least 10% and preferably by more than 50% of its initial surface. The invention is particularly of interest for dressings for healing wounds, filling and protecting cavity wounds, or for ultrasound scanning of wounds.

Description

Title of the invention: Composite protection device for molding a wound

The present invention relates to a composite protection device for molding a wound, of the heart-bark type comprising an envelope containing at least one rheo-thickening material, said envelope consisting of a stretch film of 10% minimum, preferably more than 50 % of its initial surface. The present invention is of particular interest for dressings in the healing, filling and protection of cavity wounds.

In recent years, medical devices that heal or aid in the healing of cavity wounds have been very widely developed, in particular for their ability to accelerate the speed and quality of healing of this particular type of wound.

Cavitary wounds can pose a number of well-identified problems in their management, in particular because of their high exudation capacity but also because of their irregular contours. Traditionally, the treatment recommended by nursing staff to manage this type of wound requires that it guarantee adaptability, conformability and optimal exudate management.

Thus, cotton gauzes or alginate dressings, in the form of a wick, are usually used as filling material for said cavity wounds. Secondarily to the application of this first type of dressing is generally affixed another material at the edges of the wound, on the surface. The latter effectively complements the action of the filling material and can have different possible forms, ranging from a simple polyurethane film to a complex absorbent dressing depending on the levels of exudation of the wound observed. Recently, with the emergence of negative pressure therapy (NPT), new types of composite materials are being used in the management of cavity wounds.

In this type of therapy, it is necessary to control how the cavity wound heals. Ideally, the lesion should heal deeply at the start, then close, joining the edges of the wound evenly. It is particularly desirable that the The wound does not close on the surface until the deep scarring is finished, in order to avoid the formation of cavities in the flesh which would become sites favorable to infections. To avoid the formation of these cavities during treatment with NPWT, the wound is generally filled with a porous soft or compressible material, and having properties allowing it to resist the pressure difference created inside the wound relative to ambient atmospheric pressure. The purpose of the material is to keep the edges of the wound far enough apart that they cannot grow and join to form an unwanted cavity.

Most of the TPN systems marketed today use a foam or gauze material as the wound filling material. However, porous materials of this type have the disadvantage of promoting tissue growth in their pores, tissue growth which clings to said pores, which, when the material is removed, can damage the newly formed granulation tissues and be painful for the patient. In addition, such porous materials can also leave exudates in contact with the wound, causing an accumulation of bacteria leading to infection.

Developments have thus been proposed in order to wrap porous materials such as foam or gauze with non-porous materials but also non-adherent to the skin tissues in contact with which the latter are applied. International applications W02009 / 071928 and W02009 / 071938 of Smith and Nephew have in particular proposed composite wound filling materials comprising a non-porous envelope connected to a pipe, containing a resilient, compressible material of the foam, gauze or polystyrene type. This envelope must be sufficiently rigid (70 shore) to avoid any tearing. The envelope can be additionally coated or soaked in a non-adherent gel such as a hydrogel or a silicone gel.

However, regardless of the type of care recommended by the nursing staff, the known filling materials still have insufficient conformability, synonymous with an inability to match the crevices of the lesion, thus not allowing optimal healing.

Application WO 2004/037307 from the company Johnson & Johnson proposed an alternative to known filling materials and promoting healing, consisting of filling of a cavity wound by a fluidic material, possibly being a liquid, a paste, or a non-Newtonian fluid, and preferably being partially crosslinked polyurethane intended to be as conformable as possible facing the various crevices presented by a cavity wound.

However, this material does not appear sufficient in preventing the protection of the wound against the occurrence of any external event, in particular shock. Indeed, many patients treated on an outpatient basis are potentially subject to the occurrence of external trauma, and the proper management of wound healing in these cases is now one of the prerogatives of interest. The materials as described in application WO 2004/037307 can in no case efficiently absorb any external shock, nor avoid the possible harmful consequences generated (such as for example bleeding) in the proper course of the healing process of the underlying wound.

Application WO 2015/092314 A1 from the company Urgo presents a negative pressure dressing comprising at its compressible heart channels for the drainage of exudates. The interlacing of the fibers is poorly adaptable to the crevices of the walls of cavity wounds and does not allow increased pressure to be applied to the bottom of the wound.

The publication US 2015/0272591 from Boston Scientific Scimed describes a device comprising a polymer bag containing a rheo-thickening fluid to reduce the volume of the pulmonary cavity, an expander or a tissue expander to reduce the volume of inhaled air. In this publication neither the stretchability nor the quantification of the stretchability of the polymer is discussed. In addition, this pleuro pulmonary pocket within the rib cage is sheltered from external shocks. This pocket is subject to friction due to respiratory movements, the polymer must therefore have a certain thickness and be covered with lubricant. This pocket is placed at a distance, for example in the pleural cavity and in any case outside the lung wound. Its layout is different, this pocket does not mold lung lesions.

Application WO 2008/029101 from Regent Medical offers wound care products which include rheo-thickening fluids in order to increase their resistance to puncture, for example of a needle. These fluids coat bulletproof fabrics like aramid. Alternatively, these fluids may be contained between fibrous layers under the form of a gel but this multilayer arrangement does not allow sufficient conformability to fill a cavity wound. In addition, these fibrous layers are not stretchable.

Application WO 2000/046303 from the company Extrade Hone describes a limb protector formed by a rheo-thickening fluid contained in any flexible material such as a film or a sheet of a flexible plastic material or a relatively non-porous fabric, a sheet, leather or the like. The described environments absorbing the shocks do not need to have thin walls and the stretchability is not mentioned; it’s not the same problem.

Faced with these last two requests, a person skilled in the art knows the following antagonism: a fluid wall with a thin and impermeable wall cannot withstand an external shock without breaking and a thick wall is a brake on high conformability. Thus, a thick-walled fluid or fluid pocket cannot sufficiently mold the crevices of a cavity wound. This antagonism prevents the use of these pockets for optimal conformability in the prior art.

Therefore, in the prior art if it is desired to manufacture a heart-bark dressing with an optimal conformability / burst ratio, it is advisable to choose a compressible heart, for example, based on foam, hydrated fibers or beads. polystyrene with a porous envelope or a core containing these same materials with a waterproof envelope connected to a pipe allowing to evacuate an overpressure.

Recently a surprising event occurred, the event at the origin of this invention. Inadvertently a rheo-thickening liquid was spilled on a film protecting a work surface. By folding up the film to throw it in the trash, a pocket of about 15 cl formed spontaneously. This one seemed very conformable, to have a good resistance to the compression of the fingers and especially it seemed impossible to burst this improvised pocket, posed on the work plan, by striking with the fist on this one. This film was 12 pm thick. If the same 12 μm film forms a pocket filled with water or Ketchup (described in Example 1 below), it tears at the slightest shock. We therefore observe, secondarily to an impact, an “anti-burst synergy” between this very thin film and the rheo-thickening material.

This film is characterized by its chemical composition, its thickness, its number of layers, its tensile, puncture and tear resistance, its overall stretch rate or its surface condition. By testing many films we found that the anti bursting synergy was correlated to the stretchability of the films (Example 2). In addition, in example 3, we note a synergy in the technical effect sought when we couple both the ameliorative effects on the conformability of the two constituents of the device object of the invention, namely the nature of the rheo-thickening material and that of the stretch wrap. Thus, by choosing a rheo-thickening material contained in a stretch film as core-shell, we obtain the best conformability / burst ratio.

The management of patients in an outpatient setting requires the prescription of a composite material to the multiple, complex specifications, which should, in addition to the needs described above of adaptability and conformability, protect the wound from the occurrence of a any external trauma by the damping of the latter, without however undergoing any bursting or any alteration in its structure.

There is therefore a real and important need in the provision of a new wound protection device, especially a cavity one, having both properties, possibly antagonistic, of improved conformability, pressure distribution, trauma absorption. external and non-burst. In addition, the dilation of the rheo-thickening material during its thickening increases the pressure exerted on the bottom of a venous ulcer if the material is placed between the wound and a band of compression therapy. The pressure at the bottom of the ulcer is then greater than that of compression therapy.

The present invention thus relates to a composite heart-shell protective device molding a wound comprising an envelope containing at least one rheo-thickening material, said envelope consisting of a stretch film of 10% minimum, preferably more than 50% its initial surface.

Figures

Figure 1 is a cross section of a preferred embodiment of a composite wound protection device according to the invention. FIG. 2 is a cross section of a dressing comprising a composite protection device for molding a wound according to the invention.

Figure 3 is a top view of a dressing comprising a composite protective device molding a wound according to the invention. FIG. 4A describes the force values at impact (in Newton) of a probe released on each of the composite protection devices molding a wound tested, at each impact recorded.

Figure 4B shows the force values at impact (in Newton) of a dropped probe on each of the wound protection composite devices tested as a function of time (in seconds).

Envelope

The composite protection device for molding a wound according to the invention can be likened to a device of the heart / bark type, said bark consisting of a stretch film of 10% minimum, preferably more than 50% of its initial surface.

According to a preferred embodiment of the invention, the envelope of the device has a thickness of less than 200 μm, preferably less than 100 μm, and / or greater than 5 μm, preferably greater than 15 μm, preferably greater than 40 pm, preferably between 5 and 100 pm, between 5 and 60 pm, between 15 and 80 pm or between 15 and 40 pm.

According to a preferred embodiment of the invention, the envelope of the device is stretchable so that the surface of the latter is increased by 10% minimum, preferably by 50%, preferably by 100%, preferably by more than 250% of its initial surface.

Preferably, the envelope according to the invention consists of at least one polymeric material.

By “polymeric material” is meant any macromolecular material, in particular obtained by polymerization or transformation of a precursor (monomer, pre-polymer or polymer). It can be a synthetic or natural material, preferably synthetic, for example a textile or a plastic, a combination of all these materials or even a combination of different polymers within the same material as well as the combination materials thus obtained.

According to a preferred embodiment of the invention, the polymeric material used is a polyolefin, and can be chosen from the nonlimiting list of compounds comprising inter alia, low density or high density polyethylenes, polypropylenes, polybutylenes, polymethylpentenes, and ethylene vinyl acetate polymers (EYA). The polymeric material can also be chosen from the non-limiting list of compounds comprising inter alia vinyl polymers such as polyvinyl acetates, polyvinyl alcohol, polyvinylbutyral or polyvinylformal, polyvinyl chloride derivatives (polyvinyl chloride, chloride of polyvinylene, the polyvinylchloridepropylene copolymer); polyurethanes and urea-polyurethanes, polystyrenes and their copolymers (copolymer of styrene-butadiene, styrene-acrylonitrile, styrene-butadiene-acrylonitrile), and derivatives of acrylic polymers (polyacrylates, polymethyl methacrylate, ethylene copolymer / butyl acrylate, ethylene / methyl acrylate copolymer, ethylene / methacrylic acid copolymer), polyacrylonitrile, polyesters (especially PETE, polyethylene terephthalate, polybutylene terephthalate, polyvinyl acetate, polylactic derivatives) glycolic), cellulosic films (nitrocellulose, ethylcellulose, cellulose acetate, cellulose acetate butyrate, cellulose propionate), polyimides, polyamides (nylon), phenolic and epoxy plastics, polycarbonates , phenoplasts, fluoropolymers (polytetrafluoroethylene, polyvinylidene fluoride), polyoxymethylenes, l es dimethylpolysiloxanes (silicone), polyphenylene oxides, polysulfones (PSU, PESU, PPSU), polyphenyl sulfide, and polysaccharide-based materials.

The polymeric material used in the production of the present stretchable envelope of the device which is the subject of the invention can be in almost all possible forms. It may for example be a continuous or discontinuous film, breathable or non-breathable, permeable or impermeable, transparent or opaque, a woven, knitted or non-woven film, a mesh film or even a fibrous network .

According to a preferred embodiment of the present invention, the envelope of the device consists of at least one polymeric material, preferably synthetic, preferably polyurethane.

According to a preferred embodiment of the present invention, the envelope of the device consists of at least one polymeric material, preferably synthetic, which is in the form of a continuous film, preferably made of polyurethane, of thickness included. between 5 and 100 pm, preferably between 15 and 80 pm, preferably between 40 and 60 pm and stretchable by 10% min, preferably by 50%, preferably by 100%, preferably by more than 250% of its surface initial or even more than 300 or 600%. According to an advantageous embodiment of the invention, the envelope of the device has the function of maintaining the rheo-thickening material in an enclosed space, in other words tight in order to avoid any direct contact of the latter with the wound.

According to an alternative mode, the envelope of the device is permeable, it can possibly behave like an osmotic membrane.

Preferably the envelope is oversized relative to the volume of the rheo-thickening material.

According to an alternative embodiment of the present invention, the envelope can be made of a plurality of synthetic polymeric materials optionally assembled together by heat-sealing or heat-bonding. Another mode is to manufacture the envelope by molding, by dipping molding in order to reduce the unwelcome closure zones.

According to another embodiment of the invention, the envelope constituting the composite wound protection device may have several faces and advantageously two faces, called internal wall and external wall and intended to be respectively placed in contact with the wound and in look from the outside.

According to this embodiment, the internal and / or external wall is stretchable so that the surface of the latter is increased by more than 10%, preferably by more than 50%, by 100% and even by more than 250% of its initial surface, or even more than 300 or 600%.

Preferably the internal wall can be stretchable and not elastic in order to better mold the crevices of the wound.

According to one embodiment, the internal wall and the external wall can have different stretch and permeability properties. Preferably, the internal wall and the external wall are both impermeable. Stretch polyurethanes are extremely impermeable to small molecules. The envelope may be impregnated or coated with a waterproofing agent such as an oil, a silicone, nanoparticles, etc.

In another embodiment, the envelope may have a so-called “self-sealing” zone allowing the penetration of a hypodermic needle, then its withdrawal, the self-sealing zone then closing automatically during this withdrawal. The envelope may also have an orifice provided with a non-return valve and allowing connection optionally to a glow pipe or nozzle, an orifice fitted with a filter, an electrical connection if, for example, part of the envelope is an electro-active polymer, this polymer then allowing the envelope to contract.

In another embodiment, the envelope may optionally have a "porthole" or a transparent window, for example of synthetic polymeric material or of mineral material, allowing visualization of the enclosed rheo-thickening material and / or of the possibly underlying wound .

Preferably, these last two embodiments of the invention will appear on the face of the envelope constituting the device intended to be facing the outside.

Rheo-thickening material

The composite protection device for molding a wound according to the invention can be likened to a device of the heart / bark type, said bark consisting of a stretch film of 10% minimum, preferably more than 50% of its initial surface. The latter contains a particular material, namely a rheo-thickening material.

Rheo-thickening materials belong to the category of non-Newtonian fluids in the same way as rheofluidifying materials or threshold fluids. However, they are characterized by the other materials mentioned above by a viscosity which increases when the shear speed increases. They are also said to be "dilating".

One can in particular characterize a rheo-thickening material by a critical shear rate.

The term “critical shear speed” is understood to mean any shear speed above which the value of the viscosity (measured in Pa.s) of the rheo-thickening material increases by more than an order of magnitude (that is to say at least a factor of 10 or a logarithmic unit). This corresponds to a brutal "thickening" of the suspension, due in particular to a change in the type of association between the macromolecules: at low shear rate, there are essentially intramolecular interactions and, in an adequate concentration range, a rate high shear results in intermolecular interactions and "gelation" of the suspension. According to a preferred embodiment of the invention, the rheo-thickening material consists of a suspension of a dispersed, solid or liquid phase in a liquid or gaseous dispersing phase, said material having a critical shear rate greater than 5 s ¹ , preferably greater than 10 s ¹ .

According to one embodiment of the invention, the rheo-thickening material within the meaning of the present invention is a suspension of a dispersed phase in a dispersing phase. Advantageously, this suspension can be transparent.

The dispersed phase of the constituent suspension of the rheo-thickening material can therefore be chosen from the non-limiting list of the following compounds, used alone or in mixtures, preferably gluten-free, namely corn starch, rice flour, apple flour earth, peas, cassava, amylopectin, amylose (these last two compounds can be combined in respective proportions by weight of 100 of 70/30 and preferably still 80/20), honey whose eucalyptus honey or certain of its constituents, polyethylene glycol, polypropylene glycol, a silica fume whose particles have a size between 10 and 500 nm and for example marketed under the name Aerosil® 0X50 by the company Evonik, HDK N20 pharma from the company Wacker® or the reference S5505 sold by the company Sigma Aldrich, and finally from one or more hydrophilic polymers chosen from a polyacr ylamide, polyvinylpyrrolidone, hydroxypropylcellulose, polyvinyl alcohol, polyethylene oxide, polypropylene oxide, polyethylene glycol, polylactic acid, polyurethane in hydrogel form, dimethylsiloxane, chondroitin sulfate , a hyaluronic acid or an alginate, associated with particles of size less than 500 nm, preferably consisting of one or more oxides, in particular chosen from silicon, titanium, zinc, iron, copper, or, possibly combined with sodium tetraborate or calcium carbonate.

According to a preferred embodiment of the invention, the dispersed phase of the suspension constituting the rheo-thickening material is chosen from at least one of the compounds that are bleached or unbleached corn starch, polyethylene glycol, polypropylene glycol, or silica smoke. Graphene oxide (GO), preferably at a concentration of less than 0.3%, can partially replace silica smoke. Advantageously, the rheo-thickening material is lightened and more stable. It is the same with fines or nanoparticles of cellulose. According to a preferred embodiment of the invention, the dispersing phase of the suspension constituting the rheo-thickening material is chosen from water, alcohol, glycerol, oil, physiological saline (comprising at least one of the following salts, sodium, calcium, potassium and magnesium), or a gas, and is preferably water. The osmolarity of the rheo-thickening liquid is adapted to the type of wound if the envelope is permeable.

According to a preferred embodiment of the invention, the rheo-thickening material comprises silica smoke and polypropylene glycol or silica smoke and polyethylene glycol. Advantageously, the rheo-thickening material comprises silica smoke, the particles of which have a size diameter of between 10 and 500 nm and polypropylene glycol of molecular weight between 200 and 800 g-mol-1, preferably 400 g-mol- 1. Polypropylene glycol can be replaced by polyethylene glycol of molecular weight also between 200 and 800 g-mol-1., Preferably 400 g-mol-1. These mixtures have the advantage of being radio, echo and transparent photon.

Adding a small amount of PEG or high molecular weight PPG (4,500 to 10,000) can enhance the rheo-thickening effect or even cross-link the gel.

According to a preferred embodiment of the invention, it can be a mixture containing sodium tetraborate with polyvinyl alcohol.

According to a preferred embodiment of the invention, an oil-in-water emulsion may be added to which a corn starch is added at low temperature to avoid any cooking.

According to an alternative embodiment of the invention, the rheo-thickening material may also contain any material chosen from linen, cotton, glass, carbon, aramid, silica, metals and their alloys, polymers such as as polyurethane, polystyrene or polyvinyl chloride, resins, various mineral or organic compounds put in the form of foam, fiber, powder or even granule like hollow glass microbeads, allowing to lighten the material.

Preferably said materials put in the form of granules, powders or fibers have a length or diameter of between 0.1 μm and 20 mm, preferably between 10 μm and 5 mm, preferably between 70 and 300 μm. The latter can thus form a rheo-thickening granular mass immersed in water or oil. Finally, various additives such as albumin, proteins, detergents, surfactants, emulsifiers, emollients, emulsion stabilizers, preservatives, antimicrobial or antibacterial agents such as ceftazidime or other third generation cephalosporins, miconazole, amphotericin B, methylene blue or even MgCl ₂ can be added to the composition of the rheo-thickening material.

Composite wound protection device

The composite protection device for molding a wound according to the invention can be likened to a device of the heart / bark type, said bark consisting of a stretch film of 10% minimum, preferably more than 50% of its initial surface and said the heart being a rheo-thickening material.

Preferably, the device which is the subject of the invention is defined as a composite device for filling and protecting a skin wound comprising an envelope containing at least one rheo-thickening material, said envelope being stretchable beyond 50% of its initial surface and having a thickness less than 100 µm.

According to this preferred embodiment as described in FIG. 1, the composite protection device 10 therefore comprises an envelope 12 containing at least one rheo-thickening material 11. This envelope advantageously has the form of a deformable pad which can be introduced directly into the wound.

According to one embodiment, the composite device can be used for keeping an ultrasound probe at a distance, the bag then preferably being coated with transparent echo gel.

By the terms "molding a wound" is meant that the pocket molds at least partially a wound wall, crevices of a wound wall, altered skin or crumb mucosa or contributes to at least partially making a dressing.

By “composite protection device for molding a wound” is meant any protection device for any physical and / or metabolic alteration of at least part of the skin or of the mucous membrane, such as, for example, graft, wound, wound sutured, hematoma, hemorrhage, sheet hemorrhage, epistaxis, thrombosis, burn, inflammation, edema, abrasion, laceration, bite, bedsore, perforating ailments, pilonidal cyst, ulcer, fistula, abscess, wound on stump, necrosis plaque, blister, keloid, partridge eye, horn, callus ... Or for holding a catheter, catheter, ostomy bag or medical device in place .

The term "containing" means any inclusion of at least one rheo-thickening material within an envelope defining a volume capable of being filled and circumscribing at least partially, and preferably completely said material. Ideally, the envelope completely circumscribes the rheo-thickening material, so that said material cannot be in direct contact with any of the wound surfaces or the peri-lesional skin, or even the external environment. .

By the term "film" we mean a thin layer of material, without prejudging their arrangements within the film.

By the terms "stretchable by X% of its initial surface", it is meant that a square piece of 1 cm side of the film can be stretched up to this X value without puncturing, tearing or breaking.

By the terms "a fastening strip capable of ensuring immobilization" is meant an elastic band or not, adhesive or not, a stocking, a sock or a sleeve, a lace, a bracelet, a slipper, a glove, a finger cot, a headband, clothing, orthosis or prosthesis, etc. preferably, when the device is used as a dressing, the fixing strip is an adhesive strip, preferably fixed to the device.

In this text, the numerical limits are always understood, thus, for example, "with a thickness of between 15 and 40 μm, it is understood that the thicknesses 15 and 40 are included in the interval.

According to one embodiment of the invention, the composite wound protection device has a volume of between 0.1 and 15 cm ³ , preferably between 2 and 6 cm ³ .

According to a preferred embodiment of the invention, the composite protection device for molding a wound comprises an envelope which is a polyurethane film which can be stretched beyond 100% of its initial surface and of thickness between 15 and 40 μm containing a rheo-thickening material comprising polyethylene glycol and silica fume. According to another embodiment of the invention, the composite protection device molding a wound comprises an envelope coated or covered with a substance facilitating the healing and / or positioning of the device, such as for example a gel not adherent to the wound , an ultrasound gel, a hydrogel, a gel or a silicone plate, paraffin, petrolatum, glycerol, a hydrocolloid, an alginate or a salt thereof, gelling fibers, a coated or stretchy tulle , a tulle mounted on foam, extensible or not, if necessary with limited extensibility, collagen, one or more active substances, cells, enzymes, growth factors or hemostasis products such as kaolin, calcium or chitosan.

According to different embodiments of the invention, the composite protection device for molding a wound can be in different geometric forms, such as for example a cylinder, a shell, a dual dumbbell, a cube, or even a sphere. The latter can also have a less common form of crescent or "horseshoe" type in order to offer the possibility of being inserted between two toes or on the periphery of the malleolus or even complex shapes for the face for example.

Pad

According to another embodiment of the invention, the latter consists of a wound dressing dressing comprising at least one composite protection device object of the invention.

According to this embodiment of the invention, the dressing as described in FIG. 2 or 3 may comprise a composite protection device for molding a wound 10 fixed directly to a support (23, 33). The wound-molding protection device 10 has an envelope (22, 32) enclosing or at least partially circumscribing at least one rheo-thickening material (21, 31). The envelope (22, 32) can be fixed directly to the support (23, 33), for example by means of an adhesive. The support (23, 33) associated with the composite protection device molding a wound 10 may have on its surface left free by this association an adhesive (24, 34) adherent to the skin, but repositionable. Finally, an absorbent material 25 can be associated with the periphery of the device 10 so as to come into contact with the lateral edges of the wound. The support may have a transparent window (26,36) at the interface of the place to which the composite protection device 10 is fixed. The composite protection device for molding a wound can optionally be fixed to the adhesive-coated support by means of a veil, for example made of polyethylene. Thus, the fastening line between the two materials is preferably wavy, seen from above.

Advantageously, the quantity of absorbent material within the dressing comprising at least one composite protection device for molding a wound can be increased. The absorption capacity of wound secretions is advantageously increased.

According to an alternative embodiment of the invention, the dressing can comprise a plurality of composite protection devices molding a wound, adjacent, superimposed, juxtaposed, isolated or communicating, or even concentric and directly attached to the support.

According to another alternative embodiment of the invention, the dressing may optionally include at least one chamber attached to the support and containing a plurality of composite protection devices molding a wound which are objects of the invention directly adjacent, superimposed, juxtaposed, or even concentric. Preferably the chamber or chambers have rounded angles.

Preferably, according to any one of the two alternative embodiments of the invention described above, these adjacent devices, superimposed or juxtaposed can be optionally separated by absorbent, draining, or adhesive-coated partitions. These devices can also be immobilized or made mobile relative to one another, or to one another in the case where a plurality of composite filling and protection devices have a concentric relationship with one another. They can also have similar or different volumes, sizes or shapes. According to this latter embodiment, when the composite protection device molding a wound advantageously comprises two faces called internal wall and external wall as described above, the external wall of the envelope constituting the device can be fixed directly to a support of nature adhesive plastic or any other element allowing the fixation of the assembly on the healthy skin around the wound. Similarly, the external wall of the envelope constituting the device can be fixed or incorporated within a hydrocellular dressing, a hydrocolloid dressing, an interface dressing or a sachet of granular elements. Thus, the material coming opposite the external wall of the envelope constituting the device may preferably be an elastic material, such as for example a polyurethane foam with a density and / or a volume greater than the rest of the support.

According to another alternative embodiment of the invention, the dressing may include at least one thin chamber adjoining at least one film of hydrocolloids also called "second skin".

According to another alternative embodiment of the invention, the rheo-thickening bag can be placed over a conformable dressing to serve as an interface between the dressing and a compression therapy device.

According to another embodiment, the object of the invention may be able to fix to the patient's skin a medical device, for example a catheter or a reservoir intended to receive stool or urine. In particular, the object may include a part which molds or attaches to a catheter or a probe. The pocket (s), object of the invention can also be included in a tracheostomy pad or provide a seal between the skin and an ostomy reservoir.

According to another alternative embodiment of the invention, the dressing may include a bead to protect the pocket from significant static pressure. The pocket may also contain a foam impregnated with rheo-thickening fluid, the foam opposing the excessive flattening of the pocket.

According to another alternative embodiment of the invention, the hemostatic dressing can comprise at least one chamber contained in a tulle coated with a hemostatic product or in an alginate tulle, the chamber making it possible to mold the wound or cavity perfectly hemorrhagic, this device is perfectly adapted to bleeding in the nappe. As part of emergency abdominal wounds, a large, multi-chamber dressing is offered. In war medicine, chambers containing part of the rheo-thickening material can be proposed, to which a liquid or a gel is added, if necessary, before use. The nasal hemostatic dressing may include a removable, bus-shaped chamber connected to a wire to promote removal, which leaves the hemostatic coating in place once compression and hemostasis have been achieved.

Method of manufacturing a composite wound protection device The composite protection device for molding a wound according to the invention can be produced using a heat sealer. To do this, certain lateral edges constituting said device must be heat-welded prior to its filling so as to form a receptacle intended to receive content. The latter is then filled with a rheo-thickening material as defined above by means of the payment of a pre-weighed volume. This filling can be carried out manually, or by means of an apparatus of the injector type suitable for said injection of such a type of material. Finally, before the closing of the last border, the residual air is expelled using a syringe. The composite wound protection device is then finalized by heat-sealing the last side portion (s) to be bonded. The same process can be transposed regardless of the shape of the composite wound protection device desired. The welds can be straight, rounded, wavy or even zigzag.

According to other embodiments of the invention, the composite wound protection device can also be manufactured by plasma welding, by gluing of the lateral edges constituting the envelope using an acrylic adhesive, or an adhesive based on cyanoacrylate, by laces, by staple, or by sewing. Another mode is to manufacture the envelope by molding, by dipping molding in order to reduce the unwelcome closure zones.

Preferably, the composite wound protection device is closed under vacuum.

Use of a composite wound protection device

The packaging of the device can conform to the shape of the pocket, protect it and is preferably waterproof.

In the service position, the composite protection device for molding a wound is held to the skin or to the mucosa by a suitable fixing system. Preferably, the device comprises a fixing strip capable of ensuring immobilization on the skin. In another mode, the shape of the pocket, for example between two toes and a sock, keeps the object of the invention in place. According to different embodiments of the invention, the composite device can be used in combination with one or more compression bands, compression bands, dressing (s), patch (s), or even a pressure-controlled tourniquet.

Advantageously, the composite protection device molding a wound is used in association with a band, a net, a stocking, compression or compression.

In the event of an external shock, the pressure exerted directly or indirectly on the composite protection device molding a wound is absorbed by the rheo-thickening material which solidifies at least partially.

Once the external stress of the shock is lifted, the protective device molding a wound returns to its initial viscosity, which allows it to continue to adapt to the crevices of the walls of the wound.

Examples

The object of the invention is described in more detail in the following five nonlimiting examples.

Example 1: Measurement of depreciation

We tested the damping effect of several types of composite cavity wound devices according to the subject of the invention and as described in particular in the prior art, in order to see which was the most suitable for absorbing an external shock. .

The following devices were tested, having a casing consisting of a polyurethane film 30 μm thick and containing:

- Some water

- A rheo-thickening material based on corn starch in the presence of a water solution, in a proportion of 55/45 by weight out of 100 respectively.

- A shear-thinning material based on tomato sauce, vinegar, and sugar marketed under the name of Ketchup.

- Polystyrene beads with a diameter of 1.63 mm in average diameter.

Each of the following devices has a square shape with rounded angles and internal side dimensions of 8 cm. Each of these devices has also been filled to capacity maximum in order to obtain comparable product thicknesses. It should be noted that the residual air present in the composite device which is not yet closed is withdrawn from the latter by means of a syringe and a needle, so that no gas can disturb the proper functioning of said device. composite is only present once the latter is closed. A 1.5 cm thick polyethylene foam was placed on the plate placed opposite a 100N force sensor belonging to a traction machine sold under the reference DY32 by the company MTS. Once the foam has been placed, the composite device to be tested is placed on it. A guide 15 cm long was then placed directly above the device to be tested, but without initiating any contact with it. We then zero the force sensor. We then start the acquisition of force data (in Newton) as a function of time (in seconds), then we release the distal part of a metal probe weighing 200g with a height of 15 cm, action from of which the force at impact of said probe is recorded on each of the composite devices tested as a function of time until final damping (that is to say until the cessation of secondary impacts suffered and felt).

Table 1 gives the force values measured at the impact of the probe for each of the different composite devices tested. Figure 1 has transcribed these same data in the form of a histogram. It should be noted that the force values linked to the weight of the probe (2N) are directly subtracted from the measured force values. [Table 1]

Table 1: Force values measured at impact

Measured force Pic Pic Pic Pic Pic Pic Pic Pic Pic

(in Newton) n ° ln ° 2 n ° 3 n ° 4 n ° 5 n ° 6 n ° 7 n ° 8 n ° 9

14.4 5.9 2.5 0.9 0.2 0.0 / / / polystyrene beads

Water 14.6 7.6 4.2 2.0 0.9 0.4 0.3 0.1 0.0

It is found that the device containing the rheo-thickening material makes it possible to significantly reduce the force felt at the first impact but also makes it possible to blur the shock faster than all other devices. Among the devices comprising a non-Newtonian fluid, namely either a rheo-thickening material or a shear-thinning material, that containing a rheo-thickening material demonstrates a certain superiority in the damping effort of the composite device as well in terms of the force felt at impact only at the level of the resurgence of secondary impacts felt.

Example 2: Burst test

This test is carried out by positioning protective devices molding a wound between two horizontal plates. The shock was caused by a free fall from a height of 2 m and a weight of 0.4 kg of hard rubber. The devices or bags are filled with 15 cl of liquid or liquid gel without residual air. The pockets have the shape of a fig, are closed by the tying of a multi-strand nylon thread and are filled to only 80% of their volume capacity. This solution was chosen so as not to denature the physical properties of the plastic films with glue or heat sealing. The ligature area is placed towards the zenith. Three liquids are tested: water, Ketchup and rheo-thickening material based on corn starch placed in the presence of a water solution (of the same composition as those described in Example 1). These liquids are wrapped by plastic films with a thickness of 12, 15, 20, 30, 40, 60, 90 and 100 µm of different nature and stretchability.

All pockets filled with water or Ketchup burst. All the bags filled with rheo-thickening material combined with the non-stretchable or weakly stretchable films (5% of the initial surface) burst, including by taking polypropylene or polyurethane films 100 μm thick having good rigidity, good tensile, tear and puncture resistance. With stretch films from 100 to more than 250% all the bags filled with rheo-thickening material are intact.

We can therefore clearly see the importance of the percentage of stretch of the film present in the composite device which is the subject of the invention. There is indeed a synergy of non-bursting of a stretch film pocket containing a rheo-thickening material. A pocket made with a sufficiently stretchable film of 12 µm thickness resists a violent shock unlike a weakly stretchable film of 100 µm. In this experiment, the non-bursting of a stretch film pocket depends on its percentage of stretching and not on the thickness of the film.

Example 3: Measure of conformability We tested the conformability of several types of composite cavity wound devices according to the subject of the invention and as described in particular in the prior art, in order to see which was the most suitable for marrying the crevices of a sinuous wound.

For simplicity, we have used films with substantially identical stretch, even if the prior art has not mentioned it.

Also in the present example, it should be noted that the residual air present in the composite device which is not yet closed is also withdrawn from the latter by means of a syringe and a needle, so that no gas may disturb the proper functioning of said composite device is present once the latter closed.

We tested the following devices:

- A protective device for molding a wound comprising an envelope containing 1.63 mm polystyrene beads of average diameter, said envelope being a 40 qm stretch and waterproof polyurethane film.

- A protective device molding a wound comprising an envelope containing at least one rheo-thickening material based on corn starch placed in the presence of a water solution (of the same composition as that described in Example 1), said envelope being a stretchable and waterproof polyurethane film of 100 qm.

- A protective device molding a wound comprising an envelope containing at least one rheo-thickening material based on corn starch placed in the presence of a water solution (of the same composition as that described in the example), said envelope being a 40 qm stretch and waterproof polyurethane film.

Each of the products to be tested was placed on an annular perforated steel plate 38.1 mm in diameter. By means of an upper plate, a pre-force also called pre-load of 0.5N to 50 is then applied. mm / min then once the preload value has been reached, the platform is lowered by 0.5 cm in order to apply a similar deformation to the product. The plate is then kept in this position. Finally, the deformation of the product tested is characterized, corresponding to the height of the product penetrating under the perforated tray and the lower part of the product attached to the tray. Each of the following devices has a square shape and internal lateral dimensions of 7 cm. Each of these devices has also been filled to maximum capacity in order to obtain comparable product thicknesses.

[Table 2]

Table 2: values of the deformations

Height of polystyrene balls Material Material deformation in cm + rheo-thickening + rheo-thickening polyurethane film + thickness 40 pm polyurethane film polyurethane film thickness 100 pm thickness 40 pm

Measure 2 TT Tô TT

Average 0.8 1.0 1.9

Minimum value TT Ô TT

There are two important points to note:

1- The device comprising the rheo-thickening material wrapped by a stretchable polyurethane film and with a thickness of 40 μm is the one which seems to be the most conformable, because it is the one which has the highest deformation values.

2- The product comprising the polystyrene beads wrapped in an identical film is the one which is the least conformable, behind in particular the product comprising a rheo-thickening material wrapped in a stretchable polyurethane film and with a thickness of 100 μm. We can clearly see the importance of the nature of the wrapped material present in the composite device which is the subject of the invention. Thus, a device which is the subject of the present invention comprising a rheo-thickening material allows improved conformability with regard to the polystyrene beads. We even notice a synergy in the technical effect sought when we combine both the ameliorative effects on the conformability of the two constituents of the device which is the subject of the invention, namely the nature of the rheo-thickening material and that of the stretchable envelope. In the same way, taking films of 100, 90, 80, 70, 60, 50, 40, 30, 20 and 10 μm in thickness in a given quality, there is an increase in the conformability of the film with the decrease in its thickness.

In addition, a second conformability test of a 4, 6, 9, 12, 15, 18, 20 MHz ultrasound probe is performed with and without a pocket. The pocket has a cushion shape 4 mm thick, a stretchable envelope 50 μm thick (company Prochimir® ref 5526 CX 205) filled with a rheo-thickening mixture PEG 400 - 22% silica. The pocket coated with ultrasound gel on both sides is placed on the skin. With the device which is the subject of the invention, there is an improvement effect: the very superficial structures of the venule type are not crushed, the spatial resolution is increased and above all, surprisingly and unexpectedly, the background noise is clearly reduced, which allows to discover tissue structures hitherto invisible. The PEG 400 of the mixture can be replaced by 200 or 600; the silica concentrations can vary by weight from 15 to 45%,

preferably from 18 to 25%.

Example 4: Compression test

Cylinder test

On a glass cylinder 10 cm in diameter, a pocket described in Example 2 is placed containing a rheo-thickening material, then the cylinder and the pocket are surrounded with an inflatable sleeve of the tensiometer or cuff type for measuring the blood pressure. A pocket made with a stretch film of 10, 12, 20, 30, 40, 50, 60, 70, 80, 90 or 100 pm thick withstands the maximum compression of the cuff, ie 300 mm Hg (40,000 Pa). This value is perfectly compatible with the dressing of a venous ulcer accompanied by compression therapy.

Test between two platforms

Between two horizontal plates, a pocket is placed containing a rheo-thickening material described in example 2, then a weight is placed for a total of 20 kg, including the upper plate. The bag composed with a stretch film of 20, 30, 40, 50, 60, 70, 80, 90 or 100 μm thickness resists this static compression. This value is perfectly compatible with the dressing of certain bedsores. Mannequin test

An artificial leg includes a cavity imitating a wound. The bottom of the cavity includes a pressure sensor. We fill the cavity with a pocket containing a material

rheo-thickening described in Example 2 and surround the leg with a double band exerting a pressure of 40 mm Hg (5333 Pa). We simulate a muscle contraction and the sensor registers a pressure of 58 mm Hg (7733 Pa). This surprising and unexpected increase in pressure, measured at the bottom of the wound, is ideal for the treatment of a venous ulcer.

Example 5: Method of Manufacturing a Composite Wound Protection Device

The composite protective device for molding a wound according to the invention is produced using a bag heat sealer sold by the company CCM®. In order to produce a composite wound protection device of square shape, a stretchable polyurethane film 30 μm thick is taken from the envelope, which is folded over itself. 3 of the 4 lateral portions of the device are thus heat sealed over lengths of 8 cm. In a second step, the envelope finalized in the first step is filled with a rheo-thickening material composed of 45% by weight of silica smoke sold by the company Evonik under the name Aerosil® 0X50 and 55% by weight of a solution based on polypropylene glycol 400 ref 81350 sold by the company Sigma Aldrich. The mixing is done with perfectly dehydrated silica, by stirring and by 20 kHz sonotrode. The filling is carried out using a syringe, the introduction volume being weighed beforehand. Once the device is filled, the residual air is evacuated using a syringe with a needle. Finally, during a last step, the free edges of the polyurethane film are coupled and welded using the SM type heat sealer.

In another embodiment of the polyethylene glycol 400 sold by the company Cari Roth® is mixed with silica smoke S5505, particles of 0.2 to 0.3 μm, sold by the company Sigma Aldrich. The silica particles are precipitated in ethanol and baked at 65 ° C for two hours. Then mixing with 25% by weight of silica is carried out by stirring, mixing and 20 kHz sonotrode. The bilayer film associating a co polyamide and a thermally weldable polyurethane at 40, 60, 80 or 100 μm thickness, is stretchable by 300% and is impermeable to thickening rheo liquid. This film is produced by the company Prochimir® (ref 5526 CX 205). In another embodiment, at the end of a 20 kHz, 500 w sonotrode from the company Fisherbrand®, an oil-in-water emulsion is produced with, for example, by weight 16% glycerol, 9% petrolatum, d paraffin oil 5%, PEG 600 3%, PEG 8000 1%, 66% water containing Benzolkonium chloride as an additive; then corn starch is added at low temperature until a rheo-thickening liquid is obtained (starch 51% - liquid 49%).

Here, unlike glycerol starches which are heated and become shear thinners, the mixing is done at low temperature which allows to obtain a rheo-thickening liquid. The emulsion stabilizes the dispersed starch while retaining the rheo-thickening character of the mixture. This emulsion gels at rest at 20 ° C or in the refrigerator and liquefies on contact with the heat of the skin. The envelope of the pocket, on the skin or wound side, is a 25 μm thick polyurethane membrane (non-adhesive PU ref 9832F from 3M®) and on the outside a 40 μm film (Prochimir® company ref 5526 CX 205 ). Both films are heat sealable. You can also add active ingredients to the emulsion and choose a membrane that is permeable to these ingredients. There are an infinity of possible emulsions and those skilled in the art know how to adapt the composition of the emulsion to its use, the vast majority of pharmaceutical and cosmetic milks and creams being emulsions. In commerce these emulsions are never

rheo-thickeners because they are difficult to spread. As an example we have

emulsified with Lipikar® milk sonotrode with water, then corn starch was added and a whitish rheo-thickening emulsion was obtained.

Claims

1) Composite protective device for molding a wound comprising an envelope containing at least one rheo-thickening material, said envelope consisting of a stretch film of 10% minimum, preferably more than 50% of its initial surface, and having a lower thickness at 100 mpi.

2) Device according to claim 1, characterized in that the rheo-thickening material consists of a suspension of a phase dispersed in a dispersing phase.

3) Device according to claim 2, characterized in that the dispersed phase of the suspension constituting the rheo-thickening material is chosen from at least one of the following compounds, corn starch, amylopectin, amylose, polyethylene glycol, polypropylene glycol, and / or silica smoke, preferably polyethylene glycol, polypropylene glycol and / or silica smoke.

4) Device according to claim 2, characterized in that the dispersing phase of the suspension constituting the rheo-thickening material is chosen from water, alcohol, an oil, physiological saline, a gas, preferably water.

5) Device according to any one of the preceding claims, characterized in that the rheo-thickening material comprises silica smoke, polypropylene glycol or silica smoke and polyethylene glycol.

6) Device according to any one of the preceding claims, characterized in that the rheo-thickening material has a critical shear speed greater than 5 s ¹ , preferably greater than 10 s ¹ .

7) Device according to any one of the preceding claims, characterized in that the stretch film consists of at least one polymeric material, preferably a synthetic polymeric material, preferably polyurethane or not associated with polyamide, or silicone.

8) Device according to any one of claims 1 or 7, characterized in that the polymeric material is in the form of a film with a thickness between 5 and 100 mih, preferably between 15 and 80 mih, preferably between 40 and 60 p and with a drawability of 10% minimum, preferably 50%, preferably 100%, preferably more than 250%.

9) Device according to any one of claims 1, 7 or 8, characterized in that the stretch film may be continuous or discontinuous, woven or non-woven or knitted. 10) A dressing comprising at least one composite device according to any one of the preceding claims.