WO2009006921A1

WO2009006921A1 - Microporous material for surgical implant

Info

Publication number: WO2009006921A1
Application number: PCT/EP2007/006093
Authority: WO
Inventors: Barrera Jose Bouza
Original assignee: Barrera Jose Bouza
Priority date: 2007-07-10
Filing date: 2007-07-10
Publication date: 2009-01-15

Abstract

Microporous material (1 ) for surgical implant, which comprises inorganic compounds found in bone structures, particularly calcium phosphate and mineral salts found in bone structures, characterised in that it has a cartilaginous consistency in the presence of a composition comprising an ester type compound; and in that it comprises a matrix that supports the inorganic compounds found in said bone structures. The material (1 ) can be produced by processing a solid component extracted from marine fossils and mixing it with a liquid matrix of interconnected components.

Description

D E S C R I P T I O N

"Microporous material for surgical implant"

Technical field of the invention

The present invention relates to a microporous material for surgical implant, which contains inorganic substances found in bone structures, particularly calcium phosphate, mineral salts and plant components. The invention also relates to a procedure for producing said implants and to the uses thereof.

Background of the invention

A great number of materials for reconstructive surgery are known in the technical field relating to implantology. The most well-known and widespread tend to consist of devices made from a biocompatible material, generally titanium alloys or any noble metal, as well as materials such as hydroxyapatite, which imitates bone structures. All these materials have certain limitations in terms of their implantation and their subsequent integration into the live tissue. This is due to certain drawbacks such as their hardness, as they are not cartilaginous; their reversibility; their lack of highly dispersed surfaces; and the lack of a sufficient surface area to allow a high degree of vascular infiltration into the molecule-cell exchange wall and organic fluids.

When ceramic materials are used for reconstructive purposes there appear problems because of their rigidity, which prevents said materials from being easily secured to the adjacent tissue. They can also fracture, crack and splinter, causing irreparable and irreversible losses and also prolonging the planned surgery time if these situations occur while the reconstruction is being carried out.

Generally, the materials used until now have been elements with a negative charge known as electrets, which do not contribute to the short-term neoformation of the surrounding tissue. Furthermore, said materials are not very receptive to tissue liquid exchange, which makes their integration more difficult.

Also, most of these materials are not malleable, flexible or elastic and they are difficult to adapt to surfaces with concave or convex characteristics.

Generally, to perform reconstructive surgery, the surgeon is supplied with materials that are already shaped or adapted for positioning in the required part of the body. These materials cannot be cut or bevelled with scissors or a scalpel to make them fit any kind of surface.

There is also a type of materials that help the surgeon to perform the reconstruction by preparing injectable mixtures or pastes in situ. Document WO2004/071543 discloses an injectable mixture for the replacement of bone tissue that comprises a bone cement with two components that forms a self-hardening paste; and a third component that is a liquid that cannot be mixed with the cement paste, which can be washed or removed once the injectable mixture has hardened. This mixture also comprises an organic x-ray contrast agent.

Other materials used consist of glues that make it possible to join elements of the body that have been broken by surgical intervention or by accident. Paste-like mixtures are therefore used, which can be used to secure implants as in document US 4093576, consisting of mixtures that comprise a non-water-soluble composition made from polymethacrylate and a cellulose ether. However, these pastes are not a substitute for ceramic or metal implants that must be positioned in the required areas.

Another disadvantage with the materials used until now for reconstructive surgery is that when they are implanted or inserted into the desired areas, they give off heat (exothermic reaction), which causes the surrounding live tissue be heated and there is even a small amount of localised necrosis.

Moreover, in the case of bone reconstructive surgery, the materials used to date do not achieve a better consistency than that of the autogenous bone, which means that fractures often occur in the area where the material is implanted.

An example of such a material is that known under the trade name Xilate®.

This material is irreversible and as it is stronger than the membranes of the surrounding skin or tissue, it often causes fractures or wounds to the person who carries the implant.

Moreover, there are no materials on the market for implantology or reconstructive surgery that make it possible to reconstruct large areas of bone; and most of them must be sterilised before being applied to a patient, which increases both the time needed to prepared the material and the complexity of the surgical operation.

In an attempt to solve the aforementioned problems, document

WO2006/045851 discloses a surgical material that is influential in terms of induction, conduction and osseointegration, which is made from hydrocarbons and celluloses and is highly elastic and stable.

Surprisingly, the inventors have discovered and developed a new microporous material with which to design surgical implants, which overcomes all the aforementioned drawbacks. The proposed materials are biocompatible and they allow tissue vascularisation and osseointegration.

Explanation of the invention

In order to overcome the many disadvantages of the materials and implants that exist on the market at present and that are currently applied to fill bone defects, reconstruct bone tissue or repair injuries, a microporous material for surgical implant is proposed, of the type that comprises inorganic compounds found in bone structures, particularly calcium phosphate and mineral salts found in bone structures, said material being characterised in that it has a cartilaginous consistency in the presence of a composition comprising carvacrol or a carvacrol derivative; and in that it comprises a matrix that supports the inorganic compounds found in said bone structures and that it, in turn, comprises polysaccharides, carvacrol or one of its derivatives and compounds resulting from the esterification reaction of acrylic acid or a derivative thereof with at least one polyalcohol, all the components of the matrix being interconnected.

The microporous material for surgical implant according to the invention is characterised in that the carvacrol derivative is a carvacrol ether selected from the group consisting of methylcarvacrol and ethylcarvacrol or a carvacrol ester resulting from esterification with carvacrol of the organic acids methanoic and/or ethanoic acid.

Preferably, the polysaccharides comprise ethyl cellulose. - A -

The microporous material for surgical implant according to the invention is also characterised in that the acrylic acid derivative is methyl acrylate.

According to another characteristic of the microporous material (1 ), the polyalcohol is chosen from the group consisting of propanetriol, ethanediol and alcohols with at least three hydroxyl groups.

The microporous material for surgical implant according to the invention is characterised in that the matrix that supports the inorganic compounds can be produced by mixing compounds resulting from the esterification of polyalcohols and acrylic acid or its derivatives in a percentage of 55% to 60% of the total weight of the matrix; 35% to 40% of ethyl cellulose of the total weight of the matrix; 5% to 10% of cellulose modified by substituting the hydroxyl groups for radicals chosen from the group consisting of car boxy I, linear alkyls with 1 to 6 carbon atoms, and acetate; and 0.5% to 5% of pharmaceutically acceptable excipients in relation to the total weight of the matrix, where said excipients comprise at least carvacrol and/or an ether or ester derivative thereof.

The interconnected microporous structure is produced thanks to the nature of the molecules that make up the material, due to both the interconnection of the components of the liquid matrix and the physical interactions established between said liquid matrix and the solid component that it supports.

According to another characteristic of the microporous material for surgical implant that is the object of the invention, the inorganic compounds that are found in bone structures, particularly calcium phosphate and mineral salts that are found in bone structures, are taken from marine fossils. Particularly, marine fossils consisting of coral or coralline derivatives and/or seaweed.

Preferably, the microporous material for surgical implant comprises not only carvacrol or its derivatives, but also other antiseptic substances. Preferably, the carvacrol comes from Thymus vulgaris extract.

The microporous material for surgical implant according to the invention is also characterised in that its porosity is greater than or equal to 500 microns. Depending on the purpose of this surgical microporous material, it takes the form of blocks, sheets or spheres, which can then be moulded to the place where the implant is to be inserted due their soft cartilaginous consistency.

Another object of the present invention is a procedure for producing a microporous material for surgical implant, which is characterised in that it comprises the following steps:

a) process by purifying, crushing, grinding and macerating a solid component extracted from marine fossils, which comprises a mixture of compounds that include at least calcium, magnesium, sodium, potassium, phosphates, chlorine and fluoride;

b) production of a liquid matrix or liquid component by mixing polysaccharides, carvacrol or one of its derivatives and compounds resulting from the esterification reaction of acrylic acid or a derivative thereof with at least one polyalcohol, all the components of the matrix being interconnected;

c) mixing the solid component of step a) with the liquid component of step b);

d) homogenisation to achieve a mixture that has an interconnected microporous structure and a cartilaginous consistency in the presence of a composition comprising carvacrol or a carvacrol derivative, the mixture increasing in terms of its number of functional hydroxyl groups due to a purification procedure in various consecutive phases during said homogenisation;

e) compaction of the mixture obtained from step d);

f) formation of the implants by extrusion or moulding of the compacted mixture;

g) heating the implants formed in step f) between 8O⁰C and 12O⁰C to produce a microporosity of more than or equal to 500 microns;

h) rectification and/or calibration, consisting of removing the outer layer of the implants; i) addition of a composition comprising at least one ester type compound; and

j) packaging the product consisting of the implant and the composition added in step i).

The procedure for producing a microporous material according to the invention is characterised in that the liquid matrix from step b) can be produced by mixing compounds resulting from the esterification of polyalcohols and acrylic acid or its derivatives in a percentage of 55% to 60% in relation to the total weight of the matrix; 35% to 40% of ethyl cellulose in relation to the total weight of the matrix; 5% to 10% of cellulose modified by substituting the hydroxyl groups for radicals chosen from the group consisting of carboxyl, linear alkyls with 1 to 6 carbon atoms, and acetate; and 0.5% to 5% of pharmaceutically acceptable excipients in relation to the total weight of the matrix, where said excipients comprise at least carvacrol and/or an ether or ester derivative thereof.

Preferably, the procedure for producing a microporous material according to the invention is characterised in that in step d) the mixture passes through at least three purification phases in which it comprises 60% by weight of functional hydroxyl groups; 80% by weight of functional hydroxyl groups and 90% by weight of functional hydroxyl groups, respectively.

The purpose of these purification phases is for the molecules to take on the charge and polarity that subsequently facilitate conduction and induction in the tissue around the implant.

The procedure for producing a microporous material for surgical implant according to the invention is also characterised in that the pH of the mixture produced in step b) and final product before it is packaged are controlled so that the pH is between 4.5 and 6.0.

According to another characteristic of the procedure for producing a material for surgical implant, the pH is adjusted to 5.

Preferably, the procedure for producing a material for surgical implant according to the invention includes performing quality controls on the implant material after step h) and after step i), withdrawing any units that do not comply with the pre-established criteria and feeding them back into the procedure by collecting said units in a general collector that supplies the raw materials.

Another object of the present invention is a microporous surgical implant that can be produced according to the aforementioned procedure.

Another object of the present invention is the use of the microporous material for surgical implant, or an already formed or pre-formed surgical implant as a bone structure or bone tissue substitute.

Another object of the present invention is the use of the microporous material for surgical implant, or an already formed or pre-formed surgical implant to fill bone cavities in reconstructive and/or cosmetic surgery.

Another object of the invention is the use of the microporous material for surgical implant for ophthalmology in the reconstruction of the supra- and infraorbital ridges, vertical laminas, orbital floor, zygomatic arch and malar bones.

Another object of the present invention is the use of the microporous material for surgical implant for stomatological injury surgery.

Another object of the present invention is the use of the microporous material for surgical implant for substitution or replacement in trauma injuries with bone loss.

Another object of the invention is the use of the microporous material for surgical implant for tumour lesions and lesions caused by osteomyelitis.

Brief description of the figures

By way of a non-limiting example, photographs of patients in whom the microporous surgical implant that is the object of the invention has been implanted are presented below.

Fig. 1 shows a patient with a defect in the frontal area of the skull (A), said defect having been corrected after implantation of the microporous material for surgical implant according to the invention (B).

Fig. 2 shows another intervention performed on a patient who required the implantation of a large area of material to re-establish another defect in the frontal and parietal part of the skull: Fig. 2A shows a moment during the surgical intervention after the implantation of a large plaque of microporous material with a very well-defined concavity that is suitable to cover a relatively large area of the skull. Fig. 2B shows the result of the operation once the material has been implanted.

Fig. 3 shows another example of application of the microporous material of the invention, in this case for maxillofacial reconstruction.

Detailed description of the invention As can be seen from the attached figures, the object of the present invention is a material that can be used as a surgical implant, identified in the figures by reference no. 1 , which can be supplied in the finished form and which imitates the endogenous structure that it substitutes, or it can be pre-formed, being applicable in both forms as a substitute for bone structure or bone tissue.

The material 1 that is the object of the invention is a microporous material with a composition made from components found in bone structures, particularly calcium phosphate and mineral salts, whose main characteristic is that it has a cartilaginous consistency in the presence of a composition comprising an ester type compound. This cartilaginous consistency allows the surgeon to mould the material to the most suitable shape for the place where it is to be implanted, adapting it to the particularities of each patient. A preferred composition of said microporous material 1 is given below by way of an example.

SAMPLE COMPOSITION OF AN IMPLANT:

The microporous material 1 comprises a liquid matrix made from polysaccharides, carvacrol or one of its derivatives and compounds resulting from the esterification reaction of acrylic acid or a derivative thereof with at least one polyalcohol.

The microporous material 1 also comprises a solid component extracted from marine fossils, which contains salts and other inorganic compounds that are found in bone structures, such as calcium phosphate and associated mineral salts that imitate the conditions or surroundings of the endogenous tissue.

1.- Liquid matrix or liquid component:

The excipients used are compounds known by a person skilled in the art, to give the composition antiseptic properties, the desired viscosity, etc.

The weight percentages may vary without this detracting from the properties and final consistency of the microporous material 1. The weight percentage of the compounds resulting from condensation of acrylic acid derivatives with polyalcohols is 55% to 60%; the weight percentage of ethyl cellulose is between 35% and 40%; and the weight percentage of modified cellulose is between 5% and 10% of the total weight of the liquid matrix. Likewise, a suitable amount of excipients (between 0.5% and 5%) are added to give the composition the desired properties.

The ethyl cellulose is produced according to the following sequence or reaction: (C₆H₁₀O₅)n + XC₂H₅OH (C₆H₁₀-XOC₂H₅)Ii + XH₂O

2.- Solid component extracted from marine fossils:

Also, in this case excipients are understood to be compounds known by a person skilled in the art, which provide a composition with the desired physical properties. The carvacrol or Thymus vulgaris extract that it comprises is used as an antiseptic and means that the microporous material does not have to be sterilised prior to its use, as it is already in a sterile environment.

In this solid component of the microporous material 1 , all these elements are in the form of inorganic salts e.g. calcium phosphate or hydroxyapatite.

The traces of elements such as copper, tin or zinc or the amounts of iron, chloride, etc., are even lower than those normally found in the human body, meaning that they are not harmful.

The marine fossils processed to extract these elements or solid component may consist of coralline and seaweed. The solid and liquid components are processed together to achieve a mixture with a cartilaginous consistency in the presence of a composition containing carvacrol or one of its derivatives from Thymus vulgaris extract. The cartilaginous consistency, which makes the material malleable, is maintained provided that said material is in contact with this composition with at least one carvacrol derivative or carvacrol itself; i.e. when partially submerged, fully submerged or in contact with the steam from this composition, the material 1 acquires and maintains the property of being cartilaginous.

Moreover, during said processing, the material 1 is provided with the desired microporosity, which is always equal to or more than 500 microns.

This microporosity means that after implantation of the material 1 , the blood vessels can invade it during the natural processes of angiogenesis, making it possible to vascularise the implanted area. This microporosity also promotes cell migration and invasion by the surrounding tissues (generally bone tissue and conjunctive tissue), the implant thus being perfectly integrated into the body. Furthermore, the intrinsic composition of the material itself also facilitates a greater exchange of molecules, cells and fluids in the human organism. Therefore, at least two independent phenomena facilitate the integration of the implant, promoting growth of the tissue in all directions.

The microporous material 1 for surgical implant as defined in the above example may be moulded and extended, or cut and spliced to another piece of the same material 1 to form the implant required for each area. Once it is free from the presence of the composition with carvacrol or a carvacrol derivative in which it is supplied, the microporous material 1 hardens gradually until it takes on a consistency and hardness similar to that of the bone, or even harder than the bone. This hardening procedure can be speeded up if a warm saline solution (water and electrolytes) is added to the area when it is implanted, as is commonly done during surgical interventions to imitate the endogenous environment as much as possible.

The microporous material 1 has a micro-crystalline structure, in the sense that all its components are relatively ordered, slightly opaque, which takes on particular characteristics of the autogenous bone 72 hours after having been inserted and when joined to the live tissue. This microporous material 1 for implants can be supplied with the implant shape already formed, e.g. imitating a molar, an eyeball, etc.; or in the form of blocks or sheets that the surgeon moulds, cuts (with a scalpel or scissors) and adapts to the area where it is to be placed.

It is thus anticipated that the material may be supplied in the form of spheres with a 12, 14, 16, 18, 20 and 22 mm diameter. It may also be supplied with the form of the piece that is to be replaced and/or implanted, e.g. concave areas corresponding to parts of the skull, elongated structures with the shape of bone ends, etc.

It is also presented in the form of:

- 1 to 10 cm³ pieces.

- Sheets measuring 7 cm wide, 14 cm long and 1 to 3 mm thick. - A roll measuring 7 cm wide, 17 cm long and 1 to 3 mm thick.

Blocks measuring 7cm x 2cm x 2cm.

It is particularly advantageous that the material 1 can be cut without the pores collapsing, or without the surface cracking or deforming, which enables the surgeon to adapt or personalise the implant.

PROCEDURE FOR PRODUCING THE IMPLANTS

Also by means of a non-limiting example, given below is an explanation of the procedure for manufacturing the microporous material 1 for surgical implant that is the object of the invention for the production of 7cm x 2cm x 2cm blocks. Obviously, to produce implants with other shapes all that must be done is to modify the device used to form them, whether it is a device for extruding or for moulding the microporous starting material.

The process begins by purifying, crushing, grinding and macerating the solid component extracted from marine fossils, which comprises a mixture of compounds that include at least calcium, magnesium, sodium, potassium, phosphates, chlorine and fluoride.

At the same time, a liquid matrix or liquid component is produced by mixing polysaccharides, carvacrol or one of its derivatives and compounds resulting from the esterification reaction of acrylic acid or a derivative thereof with at least one polyalcohol, all the components of the matrix being interconnected.

Then the solid component is mixed with the liquid component and they are homogenised to achieve a mixture with an interconnected microporous structure and cartilaginous consistency in the presence of carvacrol or a carvacrol derivative. In this homogenisation step, the matter or mixture is left to stand and is subjected to a purification procedure in a series of consecutive phases in which the mixture increases in terms of the number of functional hydroxyl groups.

The mixture thus produced is put under pressure (from 100 to 200 atm) to compact it and then it is extruded to form 7cm x 2cm x 2cm blocks.

The blocks thus formed are heated to a temperature of 8O⁰C to 12O⁰C so that the microporosity of the material is equal to or more than 500 microns. A control is then performed to rectify and/or calibrate the outer layer of said blocks, in order to remove rough edges or bumps.

At this point the blocks are fully or partially submerged in the composition comprising at least one carvacrol ester or ether type compound, preferably from

Thymus vulgaris extract, which acts as an aseptic agent, keeping the blocks in sterile conditions; and then the product consisting of the 7cm x 2cm x 2cm blocks and the preservative composition with said ester type compound is packaged.

pH controls are performed at different stages of the procedure for producing the microporous material for surgical implant, particularly when the liquid matrix is produced, as it must be kept at between pH 4.5 and 6, but preferably at pH 5.

As is normal in manufacturing procedures, quality and process controls are performed at different strategic points e.g. after the step when the outer layer is removed, rectified and/or calibrated; or after having added the composition comprising at least one carvacrol ester type compound or a carvacrol ether. Faulty units are recycled via a general raw material collector.

In the procedure for producing the material 1 or implant that can be produced by moulding or extruding it, the addition of antibiotic substances is anticipated, whereby, as well as being manufactured in sterile conditions and kept in a sterile environment thanks to the ester from Thymus vulgaris extract, it is designed to already include substances that are generally administered after a surgical intervention to prevent the wound from becoming infected.

Furthermore, in the extrusion and/or moulding step it is possible to produce the material 1 with different surface morphologies, whether smooth, granulose, rough, intra-and extra-porous, etc.

This material 1 can be subjected to temperatures of -5⁰C to 5O⁰C without it losing its intramolecular properties.

The preferred and normal working temperatures range between 2O⁰C and 3O⁰C.

EXAMPLE OF USES OF IMPLANTS

As can be seen in Figs 1A and 1 B, a piece of the microporous material 1 for surgical implant was applied to a patient 2 with a deformation in the frontal part 3 of the skull. The piece was previously flat and before being implanted it was pre- formed to give it the curvature and concavity typical of the endogenous bones that constitute this part of the skull. Fig. 1 B shows the successful final result of the reconstruction.

Likewise, Figs. 2A and 2B show the reconstruction carried out on a patient 2 in whom a large area of the frontal 3 and parietal 4 bones had to be replaced. Fig.

1A shows the moment when the surgeon inserted the piece of microporous material

1 according to the invention, which was sutured to the adjacent bone structures to ensure their correct positioning. Fig. 2B shows an image of the patient's head 2 with the implant already in place and with the skin already sutured. It can be seen that, as well as having been able to replace the original structure, the external appearance of the head corresponds to a normal skull that has not been operated on.

The interventions shown in Figs 1 (A and B) and 2 (A and B) show that the microporous material 1 consisting of a matrix of polysaccharides, carvacrol or one of its derivatives and compounds resulting from the esterification reaction of acrylic acid or a derivative thereof with at least one polyalcohol, all of which being interconnected and which supports the inorganic compounds found in said bone structures, makes it possible to reconstruct large areas of bone that have been damaged or have had to be replaced for traumatic or cosmetic reasons.

Another application of the material and/or implant that is the object of the invention is that described by Fig. 3 (A and B). Thus, Fig. 3A shows a person 2 with a significant facial deformation, deriving from a lack of chin or mandibular bone structure 5. This area of the maxillofacial structure is difficult to correct due to its complex shape, with concavities, convexities and uneven areas. However, using a 7 cm wide, 17 cm long and 1 to 3 mm thick roll with a cartilaginous consistency in a composition with Thymus vulgaris extract, the surgeon cut and shaped an implant to be applied and managed to correct the defect, as is shown in Fig. 3B.

As well as these spectacular results shown in Figs. 1 to 3, it must be stressed that none of the patients 2 rejected the microporous material 1 that was implanted into them, but rather the material 1 was integrated and invaded by the bone tissue and conjunctive tissue of the surrounding areas, as is shown by the subsequent X-rays, which were taken at least a week after the intervention. Data from scintigraphy with radiopharmaceuticals show that the material according to the invention presents fibrovascular integration. It must also be highlighted that all the patients 2 are in a perfect state of health and are fully satisfied with the intervention.

Although not shown in the photographs, spheres have been implanted in ocular interventions such as enucleation, evisceration and secondary implant. In the field of ophthalmology implants or the microporous material 1 for implant according to the invention are used in the reconstruction of the supra- and infra-orbital ridges, vertical laminas, orbital floor, zygomatic arch and malar bones.

As well as the uses listed above, it can also be used to fill bone cavities with perfect osseointegration in reconstructive and/or cosmetic surgery.

The microporous material 1 for surgical implant is suitable for use in stomatological injuries; for substitution or replacement in traumatic injuries with bone loss, regardless of the size of bone mass to be replaced or substituted. The microporous material 1 can also be used for tumour lesions, and especially for lesions caused by osteomyelitis.

Having sufficiently described the microporous material 1 for surgical implant that is the object of the invention and the implants that can be made from said material, it must mentioned that they provide numerous important advantages and solutions compared to the implants and materials of the prior art, which cannot feasibly be implanted in septic tissue, e.g. with endophthalmitis; they do not allow medicinal products and antibiotics to enter their infrastructure; their molecular structure does no contain bactericidal, anti-microbial and anti- infectious elements; they cannot reconstruct extensive portions of flat bones with dimensions of e.g. 2 to 225 cm²; and they need to be sterilised prior to surgery.

However, due to its cartilaginous consistency in the presence of the composition with carvacrol or a derivative thereof, which by its nature hardens once inserted into the required area of the body, the microporous material 1 for surgical implant that is the object of the invention may be individually adapted to each patient by e.g. taking an imprint of said patient's defect on a mask. The surgeon can therefore modify the material 1 during surgery by cutting with a scalpel or scissors as has been described above. Moreover, if after bevelling or cutting it is necessary to increase the height or length, all that is needed is to adapt it by cutting a portion from the available material 1 and adding it to the surface where it is needed, securing it with a catgut suture.

The material 1 can be secured to the tissue with a conventional surgical suture.

The use of the material 1 makes it possible to reduce the time and complexity of preparing surgical interventions, as no prior sterilisation is needed because the liquid in which it is fully or partially submerged provides it with sterilisation. Moreover, while it is submerged in the composition with an ester type compound, its properties remain uncontaminated. In this composition with carvacrol, the microporous material 1 can be kept for long periods of time (if it has not been contaminated) without any changes to its properties or its molecular structure.

When it is not in the presence of the composition with carvacrol, the material 1 hardens due to a natural endothermic chemical reaction without the need for catalysts or plasticisers.

It is non-toxic, bactericidal, fungicidal and anti-infectious by nature.

The dynamics of its behaviour are due to the fact that its molecular structure covers a surface area of 3500 cm² for absorptive interaction on the molecule-cell exchange wall.

The specific weight of the microporous material 1 for surgical implant is less than that of water.

As it is highly similar to the endogenous bone tissue, its application spontaneously influences the interaction between fluids, cells, molecules, ions and haematopoietic tissue, stimulating the formation of fibrinogen and mesenchymal tissue cells and giving rise to the neoformation of tissues; i.e. it is a material that is osseointegrated and that is conductive and inductive.

Claims

C L A I M S

1.- Microporous material (1 ) for surgical implant, which comprises inorganic compounds found in bone structures, particularly calcium phosphate and mineral salts found in bone structures, characterised in that it has a cartilaginous consistency in the presence of a composition comprising carvacrol or a carvacrol derivative; and in that it comprises a matrix that supports the inorganic compounds found in said bone structures and that it comprises polysaccharides, carvacrol or one of its derivatives and compounds resulting from the esterification reaction of acrylic acid or a derivative thereof with at least one polyalcohol, all the components of the matrix being interconnected.

2.- Microporous material (1 ) for surgical implant according to claim 1 , characterised in that the carvacrol derivative is a carvacrol ether selected from the group consisting of methylcarvacrol and ethylcarvacrol or a carvacrol ester resulting from esterification with carvacrol of the organic acids methanoic and/or ethanoic acid.

3.- Microporous material (1) for surgical implant according to claim 1, characterised in that the polysaccharides comprise ethyl cellulose.

4.- Microporous material (1 ) for surgical implant according to claim 1 , characterised in that the acrylic acid derivative is methyl acrylate.

5.- Microporous material (1 ) for surgical implant according to claim 1 , characterised in that the polyalcohol is selected from the group consisting of propanetriol, ethanediol or alcohols with at least three hydroxyl groups.

6.- Microporous material (1 ) for surgical implant according to any of claims 1 to 5, characterised in that the matrix that supports the inorganic compounds can be produced by mixing compounds resulting from the esterification of polyalcohols and acrylic acid or its derivatives in a percentage of 55% to 60% of the total weight of the matrix; 35% to 40% of ethyl cellulose of the total weight of the matrix; 5% to 10% of cellulose modified by substituting the hydroxyl groups for radicals chosen from the group consisting of carboxyl, linear alkyls with 1 to 6 carbon atoms, and acetate; and

0.5% to 5% of pharmaceutically acceptable excipients in relation to the total weight of the matrix, where said excipients comprise at least carvacrol and/or an ether or ester derivative thereof.

7.- Microporous material for surgical implant according to any of the previous claims, characterised in that the inorganic compounds that are found in bone structures, particularly calcium phosphate and mineral salts that are found in bone structures, are taken from marine fossils.

8.- Microporous material (1 ) for surgical implant according to claim 7, characterised in that the marine fossils consist of coralline and/or seaweed

9.- Microporous material (1 ) for surgical implant according to any of the previous claims, characterised in that the carvacrol or derivative thereof is produced from Thymus vulgaris extract.

10.- Microporous material (1) for surgical implant according to any of the previous claims, characterised in that its porosity is greater than or equal to 500 microns.

11.- Microporous material (1 ) for surgical implant according to any of the previous claims, characterised in that it takes the form of blocks, sheets or spheres.

12.- Procedure for producing a microporous material (1 ) for surgical implant according to any of claims 1 to 11 above, characterised in that it comprises the following steps: a) process by purifying, crushing, grinding and macerating a solid component extracted from marine fossils, which comprises a mixture of compounds that include at least calcium, magnesium, sodium, potassium, phosphates, chlorine and fluoride; b) production of a liquid matrix or liquid component by mixing polysaccharides, carvacrol or one of its derivatives and compounds resulting from the esterification reaction of acrylic acid or a derivative thereof with at least one polyalcohol, all the components of the matrix being interconnected; c) mixing the solid component of step a) with the liquid component of step b); d) homogenisation to achieve a mixture that has an interconnected microporous structure and a cartilaginous consistency in the presence of a composition comprising carvacrol or a carvacrol derivative, the mixture increasing in terms of its number of functional hydroxyl groups due to a purification procedure in various consecutive phases during said homogenisation; e) compaction of the mixture obtained from step d); f) formation of the implants by extrusion or moulding of the compacted mixture; g) heating the implants formed in step f) between 8O⁰C and 12O⁰C to produce a microporosity of more than or equal to 500 microns; h) rectification and/or calibration, consisting of removing the outer layer of the implants; i) addition of a composition comprising at least one ester type compound; and j) packaging the product consisting of the implant and the composition added in step i).

13.- Procedure for producing a microporous material (1 ) according to claim

12, characterised in that the liquid matrix from step b) can be produced by mixing compounds resulting from the esterification of polyalcohols and acrylic acid or its derivatives in a percentage of 55% to 60% in relation to the total weight of the matrix; 35% to 40% of ethyl cellulose in relation to the total weight of the matrix; 5% to 10% of cellulose modified by substituting the hydroxyl groups for radicals chosen from the group consisting of carboxyl, linear alkyls with 1 to 6 carbon atoms, and acetate; and 0.5% to 5% of pharmaceutically acceptable excipients in relation to the total weight of the matrix, where said excipients comprise at least carvacrol and/or an ether or ester derivative thereof.

14.- Procedure for producing a microporous material (1 ) according to claim 12, characterised in that in step d) the mixture passes through at least three purification phases in which it comprises 60% by weight of functional hydroxyl groups; 80% by weight of functional hydroxyl groups and 90% by weight of functional hydroxyl groups, respectively.

15.- Procedure for producing a microporous material (1 ) for surgical implant according to claim 12, characterised in that the pH of the mixture produced in step b) and final product before it is packaged are controlled so that the pH is between 4.5 and 6.0.

16.- Procedure for producing a microporous material (1) for surgical implant according to claim 15, characterised in that the pH is adjusted to 5.

17.- Procedure for producing a microporous material (1 ) for surgical implant according to any of claims 12 to 16, characterised in that quality controls are performed on the implant after step h) and after step i), withdrawing any units that do not comply with the pre-established criteria and feeding them back into the procedure by collecting said units in a general collector that supplies the raw materials.

18.- Microporous surgical implant (1 ) that comprises inorganic compounds found in bone structures, which can be produced using the procedure according to any of claims 12 to 17.

19.- Use of the microporous material (1 ) for surgical implant according to any of claims 1 to 11 as a substitute for bone structure or tissue.

20.- Use of the microporous material (1 ) for surgical implant according to claim 19 for filling bone cavities in reconstructive and/or cosmetic surgery.

21.- Use of the microporous material (1 ) for surgical implant according to claim 20 for ophthalmology in the reconstruction of the supra- and infra-orbital ridges, vertical laminas, orbital floor, zygomatic arch and malar bones.

22.- Use of the microporous material (1 ) for surgical implant according to claim 20 for stomatological injury surgery.

23.- Use of the microporous material (1 ) for surgical implant according to claim 20 for substitution or replacement in trauma injuries with bone loss.

24.- Use of the microporous material (1 ) for surgical implant according to claim 20 for tumour lesions and lesions caused by osteomyelitis.