Porous bone substitutes

Abstract

The present invention relates to porous bone substitute materials for bone repair, in particular for the repair of cavitary bone defects and / or for the repair of segmental bone defects.

Description

[Technical Field]

[0001] The present invention is in the field of bone repair, in particular bone substitute materials for the repair of cavitary bone defects and / or segmental bone defects. [Background technology]

[0002] Bones undergo a constant process of renewal and repair. Indeed, our bone mass thus adapts to the biomechanical stresses of our existence by replacing old tissue with new. Bones are composed of cells, namely, osteocytes, surrounded by a mineralized extracellular matrix. This matrix is ​​renewed through a balance between the actions of two types of cells: osteoblasts and osteoclasts. Osteoblasts synthesize bone matrix, while osteoclasts remove aging bone tissue under the influence of different hormones and mechanical stresses. This process endows bone with remarkable self-repair properties, allowing it to regenerate in the event of a fracture. Thus, after a fracture, realignment and maintenance of the limb are generally sufficient for healing. By generating new tissue, the osteogenic process compensates for the defect caused by the fracture and restores the bone's functional effectiveness.

[0003] However, in some cases, this natural self-repair process is insufficient, and approximately one in ten fractures is prevented by mechanical or biological problems. Furthermore, some pathologies, such as those found in household or car accidents, victims of terrorist acts, certain diseases (e.g., nonunions), or surgical interventions (removal of tumors, cysts, or infected areas), can lead to a massive loss of bone material that cannot be compensated for by natural bone formation alone. In these cases, bone reconstruction must be assisted.

[0004] One proposed solution for bone repair is the transplantation of autologous bone fragments. This is called autologous bone transplantation. Autologous transplantation does not provoke an immune defense response because the tissue is derived from the patient. However, it results in extensive cell death in the transplanted tissue. The ability of the transplant to produce new bone cells can compensate for this loss, which depends in particular on the vascularization of the transplant. This vascularization is in fact essential for the bone being reconstructed; that is, blood vessels provide the energy and nutrients necessary for cell growth. Furthermore, autologous transplantation requires two operations (harvesting and subsequent transplantation) that can induce complications (pain, abscesses, neuralgia). Another important limitation is the size of the graft required for replacement.

[0005] Another solution that has been contemplated for bone repair is the transplantation of bone chips from a donor.

[0006] Neither of these two solutions is satisfactory. For these reasons, it seems necessary to develop a bone substitute material that has properties similar to those of natural bone, but also has the ability to promote osteosynthesis by linking it to progenitor cell growth factors.

[0007] To enable the repair of bone defects, bone substitute materials must possess two important properties: - osteoconduction, which describes the ability of a material to serve as a passive support for bone regeneration; and - Osteoinduction, which is the property of materials containing proteins whose release induces the biological cascade necessary for bone formation.

[0008] Additionally, the material must be porous and absorbent.

[0009] Several types of materials have been used as passive supports for cell and tissue colonization. These can be natural or synthetic ceramics, as well as different naturally occurring materials with chemical compositions similar to those of the mineral phase of bone. The naturally occurring materials used are of various origins: examples include ceramized bovine bone or coral exoskeleton (porite), as well as calcium carbonate, which has favorable osteoconductive and biomechanical properties. The most commonly used synthetic materials for filling bone defects are two mineral species of the phosphate family, tricalcium phosphate and hydroxyapatite, either pure or in mixtures. These can be prepared in the form of chunks or granules. Controlling the density, grain size, and porosity determines the material's behavior in vivo.

[0010] However, when used, these materials cannot be used alone and must be combined with growth factors and progenitor cells. Furthermore, these materials do not allow for the restoration of continuity and bone structure in large bone defects, and they rarely combine controlled and complete biodegradability with osteoconductive and osteoinductive properties in harmony with the kinetics of bone regeneration.

[0011] US Patent Application Publication No. 2011 / 268782 describes a bone implant comprising non-decellularized bone particles, particularly bovine-derived bone particles, and a non-elastomeric, non-porous thermosetting polyurethane resin.

[0012] Therefore, the inventors have developed a novel porous bone substitute material that has excellent osteoconduction and osteoinduction while exhibiting excellent biocompatibility and degradation adapted for bone regeneration. Furthermore, the porous bone substitute material is easy for surgeons to handle and can be easily processed to fit any type of bone defect, including large bone defects. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] US Patent Application Publication No. 2011 / 268782 Summary of the Invention

[0014] Thus, the present invention provides a porous bone substitute material comprising: at least one porous elastomeric matrix, - decellularized bone particles; The present invention relates to a porous bone substitute material comprising:

[0015] The present invention is also directed to the use of said porous bone substitute material in bone repair, preferably in the repair of cavitary bone defects and / or the repair of segmental bone defects.

[0016] The present invention is also directed to a bone repair kit including a porous bone substitute material.

[0017] The present invention is also directed to a method for preparing a bone substitute material.

[0018] Thus, the present invention provides a porous bone substitute material comprising: at least one porous elastomeric matrix, - decellularized bone particles; The present invention relates to a porous bone substitute material comprising:

[0019] In the context of the present invention, a "bone substitute material" means a physical support onto which osteoprogenitor cells can adhere, migrate, proliferate and differentiate into osteoblasts, the cells responsible for bone formation on and within the surface of the bone substitute material.

[0020] Advantageously, the bone substitute material of the present invention is a composite material comprising at least one porous elastomeric matrix and decellularized bone particles, the individual properties of which combine to form a heterogeneous material (bone substitute material) with significantly improved overall performance, properties that cannot be observed with at least one elastomeric matrix or decellularized bone particles when used individually.

[0021] The inventors have surprisingly found that a porous bone substitute material according to the present invention comprising at least one elastomeric matrix and decellularized bone particles has the following properties: - sufficient mechanical properties to withstand the stresses of forces as well as the regeneration processes in the zone to be repaired and to provide a support for the bone tissue in this zone; - a porosity and interconnectivity that allows the internal vascularization of the porous bone substitute material of the invention, allowing the circulation of progenitor cells, nutrients and other molecules that intervene in the regulation of these processes; - roughness that allows cell adhesion and the adsorption of molecules that intervene in the regulation of these processes; It was shown that

[0022] More specifically, the inventors have shown that the porous bone substitute material is mechanically stable (Young's modulus E of 100-300 kPa), non-toxic (metabolic activity of mesenchymal stromal cells after 24 hours of incubation in the porous bone substitute material of the present invention is greater than 90%), biodegradable (lifespan of 12-65 months at 37°C), and osteoconductive. Indeed, the inventors have shown that the porous bone substitute material allows the attachment of progenitor cells and their proliferation, including in depth, followed by their differentiation into osteoblasts.

[0023] In the context of the present invention, an "elastomeric matrix" is a porous elastomer-based structure capable of containing decellularized bone particles. Advantageously, at least one elastomeric matrix according to the present invention has good biodegradability, good biocompatibility, and good mechanical properties.

[0024] Advantageously, the isocyanate index of the elastomeric matrix is ​​between 0.1 and 6.0. Advantageously, the isocyanate index is between 0.1 and 5.0, advantageously between 0.2 and 4.9, advantageously between 0.3 and 4.8, advantageously between 0.4 and 4.7, advantageously between 0.5 and 4.7, advantageously between 0.6 and 4.6, advantageously between 0.7 and 4.5, advantageously between 0.8 and 4.5, advantageously between 0.9 and 4.5, advantageously between 1 and 4.5, advantageously between 1.05 and 4.5, advantageously between 1.1 and 4.5, advantageously between 1.2 and 4.5, advantageously between 1.3 and 4.5, advantageously between 1.4 and 4.5, advantageously between 1.5 and 4.5, advantageously between 2.0 and 4.5, advantageously between 2.5 and 4.5, advantageously between 2.6 and 4.4, advantageously between 2.7 and 4.3, advantageously between 2.8 and 4.2, advantageously between 2.9 and 4.1, advantageously between 3.0 and 4.0.

[0025] In the context of the present invention, "elastomer" means one or more crosslinked polymers having "rubber-elastic" properties. In a particular embodiment of the present invention, the elastomer must be biocompatible and biodegradable. Advantageously, the compressive Young's modulus of the bone substitute material of the present invention is between 10 kPa and 1000 kPa.

[0026] In the sense of the present invention, a "biocompatible" elastomeric matrix is ​​an elastomeric matrix that is advantageously suitable for implantation into a patient's body, i.e., that this implantation has a favorable benefit / risk ratio, e.g., from a therapeutic point of view within the meaning of Directive 2001 / 83 / CE, i.e., the ratio of a low or even non-existent risk for the patient to the associated therapeutic benefit; and that is simultaneously suitable for incorporating decellularized bone particles, i.e., that allows the inclusion of decellularized bone particles and does not or only slightly deteriorate the activity of the decellularized bone particles contained within the matrix, and that is adapted for bone reconstruction once the bone substitute material is implanted into the body of a human or animal patient.

[0027] Within the meaning of the present invention, a "biodegradable" elastomeric matrix is ​​one that is bioresorbable and / or biodegradable and / or bioabsorbable, with the common goal of gradual elimination through one or more different or complementary mechanisms of degradation, solubilization, or absorption of the elastomeric matrix within the body of a human or animal patient into which the material is implanted.

[0028] In one particular embodiment of the invention, at least one elastomeric matrix according to the invention comprises a poly(ester-urea-urethane) based elastomer.

[0029] In one highly advantageous embodiment of the invention, at least one elastomeric matrix of the porous bone substitute material according to the invention comprises a poly(ester-urea-urethane) based elastomer, the esters being selected from among caprolactone oligomers (PCL), lactic acid oligomers (PLA), glycolic acid oligomers (PGA), hydroxybutyric acid oligomers (PHB), hydroxyvaleric acid oligomers (PVB), dioxanone oligomers (PDO), poly(ethylene adipic acid) oligomers (PEA), poly(butylene adipic acid) oligomers (PBA) or combinations thereof.

[0030] In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane)-based elastomer. In another specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(lactic acid-urea-urethane)-based elastomer. In another specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(glycolic acid-urea-urethane)-based elastomer. In another specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(hydroxyvaleric acid-urea-urethane)-based elastomer. In another specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(hydroxybutyric acid-urea-urethane)-based elastomer. In another specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(dioxanone-urea-urethane)-based elastomer. In another particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(ethylene adipic acid-urea-urethane)-based elastomer. In another particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(butylene adipic acid-urea-urethane)-based elastomer.

[0031] In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane) and poly(lactic acid-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane) and poly(glycolic acid-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane) and poly(hydroxyvaleric acid-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane) and poly(hydroxybutyric acid-urea-urethane) based elastomer. In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane) and poly(dioxanone-urea-urethane) based elastomer. In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane) and poly(ethylene adipic acid-urea-urethane) based elastomer. In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane) and poly(butylene adipic acid-urea-urethane) based elastomer.

[0032] In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(lactic acid-urea-urethane) and poly(glycolic acid-urea-urethane)-based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(lactic acid-urea-urethane) and poly(hydroxyvaleric acid-urea-urethane)-based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(lactic acid-urea-urethane) and poly(hydroxybutyric acid-urea-urethane)-based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(lactic acid-urea-urethane) and poly(dioxanone-urea-urethane)-based elastomer. In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(lactic acid-urea-urethane) and poly(ethylene adipate-urea-urethane) based elastomer. In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(lactic acid-urea-urethane) and poly(butylene adipate-urea-urethane) based elastomer.

[0033] In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(glycolic acid-urea-urethane) and poly(hydroxyvaleric acid-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(glycolic acid-urea-urethane) and poly(hydroxybutyric acid-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(glycolic acid-urea-urethane) and poly(dioxanone-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(glycolic acid-urea-urethane) and poly(ethylene adipic acid-urea-urethane) based elastomer. In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising poly(glycolic acid-urea-urethane) and poly(butylene adipic acid-urea-urethane) based elastomers.

[0034] In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(hydroxyvaleric acid-urea-urethane) and poly(hydroxybutyric acid-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(hydroxyvaleric acid-urea-urethane) and poly(dioxanone-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(hydroxyvaleric acid-urea-urethane) and poly(ethylene adipic acid-urea-urethane) based elastomer. In one specific embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(hydroxyvaleric acid-urea-urethane) and poly(butylene adipic acid-urea-urethane) based elastomer.

[0035] In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(dioxanone-urea-urethane) and poly(ethylene adipic acid-urea-urethane) based elastomer. In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(dioxanone-urea-urethane) and poly(butylene adipic acid-urea-urethane) based elastomer.

[0036] In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising poly(ethylene adipic acid-urea-urethane) and poly(butylene adipic acid-urea-urethane) based elastomers.

[0037] In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising poly(caprolactone-urea-urethane), poly(lactic acid-urea-urethane), and poly(glycolic acid-urea-urethane) based elastomers.

[0038] In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising poly(caprolactone-urea-urethane), poly(lactic acid-urea-urethane), poly(glycolic acid-urea-urethane), and poly(hydroxyvaleric acid-urea-urethane) based elastomers.

[0039] In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising poly(caprolactone-urea-urethane), poly(lactic acid-urea-urethane), poly(glycolic acid-urea-urethane), and poly(hydroxybutyric acid-urea-urethane) based elastomers.

[0040] In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane), poly(lactic acid-urea-urethane), poly(glycolic acid-urea-urethane), poly(hydroxyvaleric acid-urea-urethane), and poly(hydroxybutyric acid-urea-urethane) based elastomer. In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising a poly(caprolactone-urea-urethane), poly(lactic acid-urea-urethane), poly(glycolic acid-urea-urethane), poly(hydroxyvaleric acid-urea-urethane), poly(hydroxybutyric acid-urea-urethane), and poly(dioxanone-urea-urethane) based elastomer.

[0041] In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising poly(caprolactone-urea-urethane), poly(lactic acid-urea-urethane), poly(glycolic acid-urea-urethane), poly(hydroxyvaleric acid-urea-urethane), poly(hydroxybutyric acid-urea-urethane), poly(dioxanone-urea-urethane), and poly(butylene adipic acid-urea-urethane) based elastomers.

[0042] In one particular embodiment, at least one elastomeric matrix of the porous bone substitute material is a matrix comprising an elastomer based on poly(caprolactone-urea-urethane), poly(lactic acid-urea-urethane), poly(glycolic acid-urea-urethane), poly(hydroxyvaleric acid-urea-urethane), poly(hydroxybutyric acid-urea-urethane), poly(dioxanone-urea-urethane), poly(butylene adipic acid-urea-urethane), and poly(ethylene adipic acid-urea-urethane).

[0043] These elastomers actually allow the implementation of the present invention and have the additional advantages of being cytocompatible, allowing the restoration of physiological stress in the defective bone, avoiding the need for reoperation after the restoration, and allowing the proper reconstruction of the defective bone. Highly advantageously, at least one elastomer matrix of the porous bone substitute material is a matrix containing a poly(caprolactone-urea-urethane)-based elastomer. This matrix containing a poly(caprolactone-urea-urethane)-based elastomer also has the additional advantages of having an interconnected porous structure, osteoinductive properties adapted to bone reconstruction, and elastomeric properties that impart flexibility.

[0044] In one embodiment of the present invention, the bone particles present in the porous bone substitute material are decellularized bone particles. In the context of the present invention, "decellularized bone" refers to a bone collagen matrix composed exclusively of collagen, specifically type I collagen, in a mineral phase consisting exclusively of hydroxyapatite crystals (crystallized calcium phosphate) and calcium carbonate, and osteoinductive proteins. The presence of collagen and osteoinductive proteins allows for increased osteoconduction and osteoinduction. Advantageously, the decellularized bone is obtained from natural cancellous bone. Advantageously, the natural cancellous bone may be the femoral head of a human.

[0045] In other words, the decellularized bone according to the present invention is completely free of any bone cells (osteoblasts, osteoclasts, osteocytes, and bone margin cells) and any potentially pathogenic and / or immunogenic components. In a specific embodiment, the percentage of collagen present in the decellularized bone particles is 10-40% by weight, advantageously 15-35%. Advantageously, the decellularized bone particles are composed of type I collagen and type III collagen.

[0046] Advantageously, the decellularized bone particles have, relative to the total weight of the particles: - a proportion of lipids of less than 2% by weight, - 25-45% by weight of protein, - calcium in proportions of 10-30% by weight, - phosphorus in a proportion of 5 to 20% by weight, - a water content of less than 15% by weight, and the calcium / phosphorus ratio is advantageously between 1 and 2.2.

[0047] In one particular embodiment, the decellularized bone particles of the porous bone substitute material can be obtained from natural bone. Advantageously, the natural bone particles can be obtained from allogeneic or xenogeneic bone of human or animal origin.

[0048] Advantageously, the decellularized bone particles of the porous bone substitute material can be obtained from natural bone by one of the methods described in patent FR 2798294 or EP 0502055.

[0049] In one particular embodiment, the decellularized bone particles of the porous bone substitute material according to the invention are obtained from natural bone of human or animal origin. Advantageously, the decellularized bone particles of the porous bone substitute material according to the invention can be obtained from natural cancellous bone. Advantageously, the natural cancellous bone can be the femoral head of a human.

[0050] In a specific embodiment, the decellularized bone particles according to the present invention have a diameter of 1 nm to 1 mm. Advantageously, the diameter of the decellularized bone particles is 1 nm to 1 mm, advantageously 10 nm to 900 μm, advantageously 100 nm to 800 μm, advantageously 100 nm to 700 μm, advantageously 100 nm to 600 μm, advantageously 100 nm to 500 μm, advantageously 1 μm to 800 μm, advantageously 1 μm to 700 μm, advantageously 10 μm to 600 μm, advantageously 100 μm to 550 μm, advantageously 200 μm to 500 μm, advantageously 300 μm to 450 μm, advantageously 300 μm to 400 μm. Advantageously, the diameter of the decellularized bone particles is 300 μm to 400 μm.

[0051] As examples of decellularized bone, mention may be made in particular of Allodyn® and Osteopure® (OST Developpement, Clermont-Ferrand), in particular of human origin, or of the product Laddec® (OST Developpement, Clermont-Ferrand), in particular of animal origin.

[0052] In one advantageous embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(ester-urea-urethane)-based elastomer, wherein the ester is selected from among caprolactone oligomers (PCL), lactic acid oligomers (PLA), glycolic acid oligomers (PGA), hydroxybutyric acid oligomers (PHB), hydroxyvaleric acid oligomers (PVB), dioxanone oligomers (PDO), poly(ethylene adipate) oligomers (PEA), poly(butylene adipate) oligomers (PBA) or combinations thereof; and - Decellularized bone particles.

[0053] In a first particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(caprolactone-urea-urethane) based elastomer, and - Decellularized bone particles.

[0054] In a second particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(lactic acid-urea-urethane) based elastomer, and - Decellularized bone particles.

[0055] In a third particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(glycolic acid-urea-urethane) based elastomer, and - Decellularized bone particles.

[0056] In a fourth particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(caprolactone-urea-urethane) and poly(lactic acid-urea-urethane) based elastomer, and - Decellularized bone particles.

[0057] In a fifth particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(caprolactone-urea-urethane) and a poly(glycolic acid-urea-urethane) based elastomer, and - Decellularized bone particles.

[0058] In a sixth particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(lactic acid-urea-urethane) and a poly(glycolic acid-urea-urethane) based elastomer, and - Decellularized bone particles.

[0059] In a seventh particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising poly(caprolactone-urea-urethane), poly(lactic acid-urea-urethane) and poly(glycolic acid-urea-urethane) based elastomers, and - Decellularized bone particles.

[0060] In an eighth particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(hydroxyvaleric acid-urea-urethane) based elastomer, and - Decellularized bone particles.

[0061] In a ninth particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(hydroxybutyrate-urea-urethane) based elastomer, and - Decellularized bone particles.

[0062] In a tenth particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(dioxanone-urea-urethane) based elastomer, and - Decellularized bone particles.

[0063] In an eleventh particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(ethylene adipic acid-urea-urethane) based elastomer, and - Decellularized bone particles.

[0064] In a twelfth particular embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(butylene adipic acid-urea-urethane) based elastomer, and - Decellularized bone particles.

[0065] In one advantageous embodiment of the invention, the porous bone substitute material according to the invention consists solely of: - at least one elastomer matrix comprising a poly(ester-urea-urethane)-based elastomer, wherein the ester is selected from among caprolactone oligomers (PCL), lactic acid oligomers (PLA), glycolic acid oligomers (PGA), hydroxybutyric acid oligomers (PHB), hydroxyvaleric acid oligomers (PVB), dioxanone oligomers (PDO), poly(ethylene adipate) oligomers (PEA), poly(butylene adipate) oligomers (PBA) or combinations thereof; and - Decellularized bone particles.

[0066] In one advantageous embodiment of the invention, the porous bone substitute material according to the invention consists of: - at least one elastomer matrix comprising a poly(ester-urea-urethane)-based elastomer, wherein the ester is selected from among caprolactone oligomers (PCL), lactic acid oligomers (PLA), glycolic acid oligomers (PGA), hydroxybutyric acid oligomers (PHB), hydroxyvaleric acid oligomers (PVB), dioxanone oligomers (PDO), poly(ethylene adipate) oligomers (PEA), poly(butylene adipate) oligomers (PBA) or combinations thereof; and - Decellularized bone particles.

[0067] Regardless of the above-described embodiment, the decellularized bone particles can be obtained from natural bone of human or animal origin, or from synthetic bone. Advantageously, the decellularized bone particles have a diameter of 1 nm to 1 mm, advantageously 300 μm to 400 μm.

[0068] In one particularly advantageous embodiment of the invention, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(caprolactone-urea-urethane) based elastomer, and - Decellularized bone particles.

[0069] Advantageously, the inventors have found that a specific combination of decellularized bone particles and at least one elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer confers improved biocompatibility to porous bone substitute materials due to the presence of hydroxyapatite. Indeed, the degradation of at least one elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer creates a slightly acidic environment, which leads to a decrease in cell proliferation. The addition of decellularized bone particles makes it possible to neutralize this acidity due to the presence of hydroxyapatite.

[0070] The inventors have also demonstrated that a specific combination of decellularized bone particles and at least one elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer allows for increased osteoinduction compared to the use of an elastomeric matrix containing only a poly(caprolactone-urea-urethane)-based elastomer. Indeed, the addition of decellularized bone particles leads to increased cell adhesion and mineralization without the addition of exogenous factors, due to modification of the surface topography of the porous bone substitute material and / or salting out of calcium ions.

[0071] Advantageously, the porous bone substitute material according to the invention consists solely of: - at least one elastomer matrix comprising a poly(caprolactone-urea-urethane) based elastomer, and - Decellularized bone particles.

[0072] Advantageously, the porous bone substitute material according to the invention consists of: - at least one elastomer matrix comprising a poly(caprolactone-urea-urethane) based elastomer, and - Decellularized bone particles.

[0073] Advantageously, the porous bone substitute material according to the invention comprises: - at least one elastomer matrix comprising a poly(caprolactone-urea-urethane) based elastomer, and - Decellularized bone particles obtained from natural bone of human or animal origin or from synthetic bone.

[0074] Advantageously, the porous bone substitute material according to the invention consists of: - at least one elastomer matrix comprising a poly(caprolactone-urea-urethane) based elastomer, and - Decellularized bone particles obtained from natural bone of human or animal origin or from synthetic bone.

[0075] Advantageously, the porous bone substitute material according to the invention comprises: - at least one porous elastomeric matrix comprising a poly(caprolactone-urea-urethane) based elastomer, and - decellularized bone particles with a diameter between 1 nm and 1 mm, advantageously between 300 μm and 400 μm.

[0076] Advantageously, the porous bone substitute material according to the invention comprises: - at least one porous elastomeric matrix comprising a poly(caprolactone-urea-urethane) based elastomer, and - decellularized bone particles having a diameter between 1 nm and 1 mm, advantageously between 300 μm and 400 μm, obtained from natural bone of human or animal origin or from synthetic bone.

[0077] In one particular embodiment of the invention, the decellularized bone particles comprise at least 10% by weight of the porous bone substitute material. Advantageously, the decellularized bone particles comprise at least 11% by weight of the porous bone substitute material, advantageously at least 12% by weight of the porous bone substitute material, advantageously at least 13% by weight, advantageously at least 14% by weight, advantageously at least 15% by weight, advantageously at least 16% by weight, advantageously at least 17% by weight, advantageously at least 18% by weight, advantageously at least 19% by weight, advantageously at least 20% by weight, advantageously at least 21% by weight, advantageously at least 22% by weight, advantageously at least 23% by weight, advantageously at least 24% by weight, advantageously at least 25% by weight, advantageously at least 26% by weight, advantageously at least 27% by weight, advantageously at least 28% by weight, advantageously at least 29% by weight, advantageously at least % by weight, advantageously at least 30% by weight, advantageously at least 31% by weight, advantageously at least 32% by weight, advantageously at least 33% by weight, advantageously at least 34% by weight, advantageously at least 35% by weight, advantageously at least 36% by weight, advantageously at least 37% by weight, advantageously at least 38% by weight, advantageously at least 39% by weight, advantageously at least 40% by weight, advantageously at least 41% by weight, advantageously at least 42% by weight, advantageously at least 43% by weight, advantageously at least 44% by weight, advantageously at least 45% by weight, advantageously at least 46% by weight, advantageously at least 47% by weight, advantageously at least 48% by weight, advantageously at least 49% by weight, advantageously at least 50% by weight. Advantageously, the decellularized bone particles constitute 10% to 50% by weight of the porous bone substitute material.Advantageously, the decellularized bone particles represent 11% to 50% by weight of the porous bone substitute material, advantageously 12% to 50% by weight, advantageously 13% to 50% by weight, advantageously 14% to 50% by weight, advantageously 15% to 50% by weight, advantageously 16% to 50% by weight, advantageously 17% to 50% by weight, advantageously 18% to 50% by weight, advantageously 19% to 50% by weight, advantageously 20% to 50% by weight, advantageously 21% to 50% by weight, advantageously 22% to 50% by weight, advantageously 23% to 50% by weight, advantageously 24% to 50% by weight, advantageously 25% to 50% by weight % to 50% by weight, advantageously 26% to 50% by weight, advantageously 27% to 50% by weight, advantageously 28% to 50% by weight, advantageously 29% to 50% by weight, advantageously 30% to 50% by weight, advantageously 31% to 50% by weight, advantageously 32% to 50% by weight, advantageously 33% to 50% by weight, advantageously 34% to 50% by weight, advantageously 35% to 50% by weight, advantageously 36% to 50% by weight, advantageously 37% to 50% by weight, advantageously 38% to 50% by weight, advantageously 39% to 50% by weight, advantageously 40% to 50% by weight.

[0078] In one highly advantageous embodiment of the invention, the decellularized bone particles comprise 33% by weight of the porous bone substitute material, and in another highly advantageous embodiment of the invention, the decellularized bone particles comprise 50% by weight of the porous bone substitute material.

[0079] In a particular embodiment of the present invention, the porous bone substitute material has multiscale pore sizes of 50 μm to 2000 μm. In the context of the present invention, the terms "pore size" and "pore diameter" can be used interchangeably. "Multiscale pore size" refers to a variable distribution of pore sizes, i.e., a distribution of pore sizes that includes pores of several microns as well as a variable proportion of smaller pores. As an example, a bone substitute material having multiscale pore sizes of 50 μm to 2000 μm means that the bone substitute material contains pores with variable sizes from 50 μm to 2000 μm simultaneously and within the same porous bone substitute material. As a non-limiting example, a bone substitute material having multiscale pore sizes of 50 μm to 2000 μm means that the bone substitute material simultaneously and in the same bone substitute material contains pores having a size of, for example, 50 μm, 100 μm, 500 μm, 1500 μm, and 2000 μm.

[0080] Advantageously, the multiscale pore size of the porous bone substitute material is between 50 μm and 2000 μm, advantageously between 50 μm and 1500 μm, advantageously between 50 μm and 1000 μm, advantageously between 50 μm and 800 μm, advantageously between 100 μm and 1500 μm, advantageously between 100 μm and 1000 μm, advantageously between 100 μm and 800 μm.

[0081] In one advantageous embodiment of the invention, the pores of the bone substitute material have a rough surface.

[0082] In the sense of the present invention, a pore size greater than 50 nm is referred to as macroporous, a pore size less than 2 nm is referred to as microporous, and a pore size between 2 nm and 50 nm is referred to as mesoporous. Advantageously, the porous bone substitute material has macroporosity.

[0083] In one advantageous embodiment of the invention, the porous bone substitute material has a total porosity of 60% or more. In the sense of the invention, "total porosity" refers to the ratio of the volume of the space free of material to the overall volume of the porous bone substitute material. Advantageously, the total porosity of the porous bone substitute material is 60% or more, advantageously 61% or more, advantageously 62% or more, advantageously 63% or more, advantageously 64% or more, advantageously 65% ​​or more, advantageously 66% or more, advantageously 67% or more, advantageously 68% or more, advantageously 69% or more, advantageously 70% or more, advantageously 71% or more, advantageously 72% or more, advantageously 73% or more, advantageously 74% or more, advantageously 75% or more, advantageously 76% or more, advantageously 77% or more, advantageously 78% or more, advantageously is 79% or more, advantageously 80% or more, advantageously 81% or more, advantageously 82% or more, advantageously 83% or more, advantageously 84% or more, advantageously 85% or more, advantageously 86% or more, advantageously 87% or more, advantageously 88% or more, advantageously 89% or more, advantageously 90% or more, advantageously 91% or more, advantageously 92% or more, advantageously 93% or more, advantageously 94% or more, advantageously 95% or more, advantageously 96% or more, advantageously 97% or more, advantageously 98% or more, advantageously 99% or more. In one particularly advantageous embodiment, the porous bone substitute material has a total porosity of 80% or more.

[0084] Advantageously, the total porosity of the porous bone substitute material is between 60% and 95%, advantageously between 61% and 89%, advantageously between 62% and 88%, advantageously between 63% and 87%, advantageously between 64% and 86%, advantageously between 65% and 85%, advantageously between 66% and 84%, advantageously between 67% and 83%, advantageously between 68% and 82%, advantageously between 69% and 81%, advantageously between 70% and 80%. In one highly advantageous embodiment, the porous bone substitute material has a total porosity of between 70% and 90%.

[0085] In one particular embodiment of the invention, the porous bone substitute material has an inter-pore interconnectivity of between 60% and 100%, advantageously between 65% and 100%, advantageously between 70% and 100%, advantageously between 75% and 100%, advantageously between 80% and 100%, advantageously between 85% and 100%, advantageously between 90% and 100%, advantageously between 91% and 100%, advantageously between 92% and 100%, advantageously between 93% and 100%, advantageously between 94% and 100%, advantageously between 95% and 100%, advantageously between 96% and 100%, advantageously between 97% and 100%, advantageously between 98% and 100%, advantageously between 99% and 100%.

[0086] In one highly advantageous embodiment of the invention the pore-pore interconnectivity is greater than 65%, advantageously greater than 70%, advantageously greater than 75%, advantageously greater than 80%, advantageously greater than 85%, advantageously greater than 90%, advantageously greater than 91%, advantageously greater than 92%, advantageously greater than 93%, advantageously greater than 94%, advantageously greater than 95%, advantageously greater than 96%, advantageously greater than 97%, advantageously greater than 98%, advantageously greater than 99%. In one highly advantageous embodiment of the invention the porous bone substitute material has an pore-pore interconnectivity of 100%.

[0087] In one highly advantageous embodiment of the invention, the porous bone substitute material according to the invention has a multiscale pore size of 50 μm to 2000 μm, a total porosity of 60% to 95%, and an interconnectivity between pores of 60% to 100%. Advantageously, the porous bone substitute material according to the invention has a multiscale pore size of 50 μm to 2000 μm, a total porosity of 70% to 85%, and an interconnectivity between pores of 100%.

[0088] In one highly advantageous embodiment, a porous bone substitute material comprising at least one elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer and decellularized bone particles has a multiscale pore size of 50 μm to 2000 μm, a total porosity of 60% to 95%, and an inter-pore interconnectivity of 60% to 100%. Advantageously, a porous bone substitute material comprising at least one elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer and decellularized bone particles has a multiscale pore size of 50 μm to 2000 μm, a total porosity of 70% to 85%, and an inter-pore interconnectivity of 100%. The porosity, pore size, and interconnectivity of a material have a significant impact on the ability of the porous bone substitute material to vascularize and gradually resorb.

[0089] Therefore, due to its total porosity of 70% to 85% and its multiscale pore size of 50 μm to 2000 μm, a porous bone substitute material comprising at least one elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer and decellularized bone particles is highly suitable for cell migration and osteogenesis within the porous bone substitute material. Furthermore, the multiscale pore size of 50 μm to 2000 μm and 100% inter-pore interconnectivity allow for the regulation of angiogenesis and osteogenesis within the porous bone substitute material itself. Indeed, the interconnected porous network allows for the induction of attachment and cell growth, and thus the growth of new bone. Therefore, a porous bone substitute material comprising at least one elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer and decellularized bone particles allows for the migration of progenitor cells and their differentiation into osteoblasts, thereby producing an osteoconductive material.

[0090] The size of the porous bone substitute material depends on the size and thickness of the bone to be reconstructed. In a particular embodiment of the present invention, the porous bone substitute material has a size of 10 mm to 20 cm and a thickness of 100 μm to 4 cm. Advantageously, the size of the porous bone substitute material is 10 mm to 20 cm, advantageously 50 mm to 20 cm, advantageously 100 mm to 20 cm, advantageously 500 mm to 20 cm, advantageously 1 cm to 20 cm, advantageously 2 cm to 20 cm, advantageously 3 cm to 20 cm, advantageously 4 cm to 20 cm, advantageously 5 cm to 20 cm, advantageously 6 cm to 20 cm, advantageously 7 cm to 20 cm, advantageously 8 cm to 20 cm, advantageously 9 cm to 20 cm, advantageously 10 cm to 20 cm, advantageously 11 cm to 20 cm, advantageously 12 cm to 20 cm, advantageously 13 cm to 20 cm, advantageously 14 cm to 20 cm, advantageously 15 cm to 20 cm. In one particular embodiment of the invention, the size of the porous bone substitute material is 10 cm, especially when the bone to be reconstructed is a long bone.

[0091] Advantageously, the thickness of the porous bone substitute material is 100 μm to 4 cm, advantageously 200 μm to 4 cm, advantageously 500 μm to 4 cm, advantageously 1 mm to 4 cm, advantageously 1 cm to 4 cm, advantageously 1 cm to 3 cm. In one advantageous particular embodiment, the thickness of the porous bone substitute material is 1 cm to 3 cm, especially when the bone to be reconstructed is a long bone. In another advantageous particular embodiment, the thickness of the porous bone substitute material is 100 μm to 1 cm, especially when the bone to be reconstructed is a flat bone.

[0092] In one particular embodiment of the invention, the porous bone substitute material has a thickness of at least 0.1 cm 3 Advantageously, the porous bone substitute material has a volume of at least 0.2 cm 3 a volume of advantageously at least 0.3 cm 3 , advantageously at least 0.4 cm 3 , advantageously at least 0.5 cm 3 , advantageously at least 0.6 cm 3 , advantageously at least 0.7 cm 3 , advantageously at least 0.8 cm 3, advantageously at least 0.9 cm 3 , advantageously at least 1 cm 3 , advantageously at least 2 cm 3 , advantageously at least 3 cm 3 , advantageously at least 4 cm 3 , advantageously at least 5 cm 3 , advantageously at least 6 cm 3 , advantageously at least 7 cm 3 , advantageously at least 8 cm 3 , advantageously at least 9 cm 3 , advantageously at least 10 cm 3 , advantageously at least 20 cm 3 , advantageously at least 30 cm 3 , advantageously at least 40 cm 3 , advantageously at least 50 cm 3 , advantageously at least 60 cm 3 , advantageously at least 70 cm 3 , advantageously at least 80 cm 3 , advantageously at least 90 cm 3 , advantageously at least 100 cm 3 , advantageously at least 150 cm 3 , advantageously at least 200 cm 3 , advantageously at least 250 cm 3 , advantageously at least 300 cm 3 , advantageously at least 350 cm 3 , advantageously at least 400 cm 3 In one advantageous embodiment, the porous bone substitute material has a volume of 0.1 to 400 cm 3 It has a volume of

[0093] In one embodiment of the present invention, the bone substitute material may have various shapes, advantageously cylindrical, planar or prismatic, and advantageously may be in the form of a flexible porous sponge, a flexible porous membrane or a flexible porous film.

[0094] In a specific embodiment of the present invention, the bone substitute material of the present invention is used alone. In another embodiment of the present invention, the bone substitute material can be further used in combination with an active agent. Advantageously, the active agent is disposed inside the bone substitute material of the present invention, partially or completely covering the pores of the bone substitute material. Advantageously, the active agent can be added by one of the following methods: coating the bone substitute material with the active agent, immersing the bone substitute material in the active agent, spraying the active agent onto the bone substitute material, vaporizing the active agent onto the bone substitute material, or any other technique known to those skilled in the art that allows filling and / or compensating the pores of the bone substitute material. Advantageously, the active agent can be any therapeutic agent or pharmaceutically active ingredient (including, but not limited to, nucleic acids, proteins, lipids, and carbohydrates) that has the desired physiological properties to be applied to the implantation site. Therapeutic agents include, but are not limited to, anti-infective agents such as antibiotics and antivirals; chemotherapeutic agents (e.g., anti-cancer agents); anti-rejection agents; analgesics and analgesic combinations; anti-inflammatory agents; hormones such as steroids; growth factors (including, but not limited to, cytokines, chemokines, and interleukins), clotting factors (Factor VII, Factor VIII, Factor IX, Factor X, Factor XI, Factor XII, Factor V), albumin, fibrinogen, von Willebrand factor, thrombin inhibitors, antithrombotic agents, thrombolytic agents, fibrinolytic agents, vasospasm inhibitors, calcium channel blockers, vasodilators, antihypertensive agents, antibacterial agents, antibiotics, surface glycoprotein receptor inhibitors, antiplatelet agents, antimitotic agents, microtubule inhibitors. This list includes, but is not limited to, agents, antisecretory agents, actin inhibitors, remodeling inhibitors, antisense nucleotides, antimetabolites, antiproliferative agents, anti-cancer chemotherapeutic agents, steroidal anti-inflammatory agents, nonsteroidal anti-inflammatory drugs, immunosuppressants, growth hormone antagonists, growth factors, dopamine agonists, radiotherapeutic agents, peptides, proteins, enzymes, extracellular matrix components, angiotensin converting enzyme inhibitors (ACE), free radical scavengers, chelating agents, antioxidants, antipolymerase agents, antivirals, photodynamic therapy agents and gene therapy agents, and other naturally occurring or genetically modified proteins, polysaccharides, glycoproteins and lipoproteins, or combinations thereof.In one highly advantageous embodiment of the invention, the active agent is a combination of therapeutic agents, and in particular a combination of an antibiotic and a growth factor.

[0095] Another aspect of the present invention relates to a porous bone substitute material according to the present invention for use in bone repair. In the context of the present invention, "bone repair" refers to the reconstruction of damaged bone by inducing bone formation. The porous bone substitute material according to the present invention may be useful for repairing various orthopedic lesions. Advantageously, the porous bone substitute material according to the present invention may be used for the repair of cavitary bone defects and / or segmental bone defects. Advantageously, the porous bone substitute material according to the present invention may be used for the repair of cavitary bone defects. Advantageously, the porous bone substitute material according to the present invention may be used for the repair of segmental bone defects. Advantageously, the porous bone substitute material according to the present invention may be used for the repair of maxillofacial bone defects.

[0096] In the sense of the present invention, a "cavitary bone defect" is defined as a cavity of at least 0.1 cm without loss of continuity relative to the entire surface of the intact bone. 3 Advantageously, the volume of bone loss without loss of continuity is at least 0.1 cm 3 Advantageously, the volume of bone loss without loss of continuity is at least 0.2 cm 3 , advantageously at least 0.3 cm 3 , advantageously at least 0.4 cm 3 , advantageously at least 0.5 cm 3 , advantageously at least 0.6 cm 3 , advantageously at least 0.7 cm 3 , advantageously at least 0.8 cm 3 , advantageously at least 0.9 cm 3 , advantageously at least 1 cm 3 , advantageously at least 2 cm 3 , advantageously at least 3 cm 3 , advantageously at least 4 cm 3 , advantageously at least 5 cm 3 , advantageously at least 6 cm 3, advantageously at least 7 cm 3 , advantageously at least 8 cm 3 , advantageously at least 9 cm 3 , advantageously at least 10 cm 3 , advantageously at least 20 cm 3 , advantageously at least 30 cm 3 , advantageously at least 40 cm 3 , advantageously at least 50 cm 3 , advantageously at least 60 cm 3 , advantageously at least 70 cm 3 , advantageously at least 80 cm 3 , advantageously at least 90 cm 3 , advantageously at least 100 cm 3 , advantageously at least 150 cm 3 , advantageously at least 200 cm 3 , advantageously at least 250 cm 3 , advantageously at least 300 cm 3 , advantageously at least 350 cm 3 , advantageously at least 400 cm 3 In one advantageous embodiment, the volume of bone loss without loss of continuity is between 1 and 400 cm relative to the total surface of the bone without defects. 3 is.

[0097] In the sense of the present invention, a "segmental bone defect" is a longitudinal bone loss of at least 10 mm with loss of continuity in relation to the bone without the defect. Advantageously, the bone loss with loss of continuity is at least 10 mm, advantageously at least 50 mm, advantageously at least 100 mm, advantageously at least 500 mm, advantageously at least 1 cm, advantageously at least 2 cm, advantageously at least 3 cm, advantageously at least 4 cm, advantageously at least 5 cm, advantageously at least 6 cm, advantageously at least 7 cm, advantageously at least 8 cm, advantageously at least 9 cm, advantageously at least 10 cm, advantageously at least 11 cm, advantageously at least 12 cm, advantageously at least 13 cm, advantageously at least 14 cm, advantageously at least 15 cm.

[0098] Examples of situations in which such defects may exist include situations following traumatic injury with segmental bone loss, surgery for bone tumors in which bone is resected, and following total joint arthroplasty (e.g., implantation with interdigitation), bone loss due to infection, and congenital defects. The porous bone substitute material of the present invention can be used as an implant for prosthetic bone remodeling or replacement in orthopedic surgery, including hip joint re-exploration, replacing bone defects in traumatology, and implants for remodeling or filling periodontal defects and extracted tooth sockets in maxillofacial surgery, including crest augmentation and sinus lift. The porous bone substitute material of the present invention can thus be used to correct any number of bone defects at a bone repair site.

[0099] In a specific embodiment of the present invention, the porous bone substitute material of the present invention can be used to repair any type of bone of human or animal origin. In a specific embodiment, the porous bone substitute material of the present invention can be used to repair long bones. Examples of long bones include, among others, the humerus, femur, tibia, fibula, radius, and ulna. In a specific embodiment, the porous bone substitute material of the present invention can be used to repair short bones. Examples of short bones include, among others, the vertebrae, patella, carpal bones, and tarsal bones. In a specific embodiment, the porous bone substitute material of the present invention can be used to repair flat bones. Examples of flat bones include, among others, the ribs, skull, ilium, scapula, and sternum. Advantageously, the porous bone substitute material of the present invention can be used to repair maxillofacial bones.

[0100] In one particular embodiment of the invention, the bone repair is 5% or more by volume of the volume of the bone to be repaired. Advantageously, the bone repair is 6% or more by volume of the volume of the bone to be repaired, advantageously 7% or more, advantageously 8% or more, advantageously 9% or more, advantageously 10% or more, advantageously 11% or more, advantageously 12% or more, advantageously 13% or more, advantageously 14% or more, advantageously 15% or more, advantageously 16% or more, advantageously 17% or more, advantageously 18% or more, advantageously 19% or more, advantageously 20% or more, advantageously 21% or more, advantageously 22% or more, advantageously 23% or more, advantageously 24% or more, advantageously 25% or more, advantageously 26% or more, advantageously 27% or more, advantageously 28% or more, advantageously 29% or more, advantageously 30% or more, advantageously 31% or more, advantageously 32% or more, advantageously 33% or more, advantageously 34% or more, advantageously 35% or more, advantageously 36% or more, advantageously 37% or more, advantageously 38% or more, advantageously 39% or more, advantageously 40% or more, advantageously 41% or more, advantageously 42% or more, advantageously 43% or more, advantageously 44% or more, advantageously 45% or more, advantageously 46% or more, advantageously 47% or more, advantageously 48% or more, advantageously 49% or more. Advantageously, the bone repair is 50% or more by volume of the volume of the bone to be repaired.

[0101] In one highly advantageous embodiment of the invention, the porous bone substitute material according to the invention can be used for bone repair in humans or animals, by way of example only, the animals may be horses, ponies, dogs, cats, rats, mice, pigs, sows, cows, steers, bulls, calves, goats, ewes, rams, female lambs, male lambs, donkeys, Bactrian camels, dromedaries, this list being non-limiting.

[0102] Another aspect of the present invention relates to a bone repair kit comprising a porous bone substitute material according to the present invention and a fixation element. Advantageously, the bone repair kit comprises a porous bone substitute material comprising at least one elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer and decellularized bone particles according to the present invention, and a fixation element. In the context of the present invention, a "fixation element" refers to an internal or external tubular or annular metal plate or fixture intended to hold the porous bone substitute material according to the present invention in place on the bone to be repaired until the bone has consolidated. Advantageously, the fixation element can be a plate with a threaded hole that allows the installation of a counterscrew, preventing any back-out of the screw, such as a Surfix® fixation element. In another embodiment, the fixation element can be a polyetheretherketone (PEEK) or steel plate from RiSystem.

[0103] Another aspect of the present invention relates to a method for preparing a porous bone substitute material according to the present invention. In one particular embodiment of the present invention, the porous bone substitute material according to the present invention is obtained by the poly-HIPE method (formation of a high internal phase emulsion and polymerization / crosslinking). A high internal phase emulsion, or HIPE, consists of an immiscible liquid / liquid dispersion system in which the volume of the internal phase, also called the dispersed phase, occupies more than about 74-75% of the total volume of the emulsion, i.e., a volume larger than what is geometrically possible due to the compact packaging of monodisperse spheres.

[0104] In one particular embodiment, the method for preparing a porous bone substitute material comprises the steps of: a) preparing an organic phase containing compounds necessary for the synthesis of poly(ester-urea-urethane); b) adding water and decellularized bone particles to the organic phase of step a) to form an emulsion; c) polymerizing / crosslinking the emulsion containing the decellularized bone particles of step c) to obtain said porous bone substitute material; d) washing the porous bone substitute material obtained in step c); e) drying the porous bone substitute material obtained in step d).

[0105] In one embodiment of the present invention, step a) consists of preparing an organic phase containing the compounds necessary for the synthesis of poly(ester-urea-urethane). Advantageously, the organic phase further comprises an oligoester, an organic solvent for the oligoester, a crosslinker, a catalyst, and a surfactant. Advantageously, the organic phase comprises toluene, a polycaprolactone triol oligomer, a surfactant Span 80, a crosslinker hexamethylene diisocyanate (HMDI), and a catalyst dibutyltin dilaurate (DBTDL).

[0106] In one particular embodiment, step a) comprises a first step a1) consisting of solubilizing the polycaprolactone triol oligomer and the surfactant Span 80 in toluene, followed by a second step a2) of adding the crosslinker HMDI and the catalyst DBTDL to the solution of step a1) to form an organic layer. In one advantageous embodiment of the present invention, 7 ml of toluene is used, along with 1.3 g of the polycaprolactone triol oligomer, 1.3 g of the surfactant Span 80, 1.04 ml of the crosslinker HMDI, and 12 drops of the catalyst DBTDL. Advantageously, a person skilled in the art can adapt the amounts of toluene, polycaprolactone triol oligomer, surfactant Span 80, crosslinker HMDI, and catalyst DBTDL depending on the desired pore size of the porous bone substitute material.

[0107] In a particular embodiment, step b) of the method comprises adding water to the organic phase to form an emulsion, and then adding decellularized bone particles to the emulsion. Advantageously, water and decellularized bone particles are introduced gradually and simultaneously under stirring until an emulsion is obtained. Advantageously, the water is sterile purified water. Advantageously, a person skilled in the art can adapt the amount of water depending on the pore size desired for the porous bone substitute material. Advantageously, the amount of water added is 34 mL.

[0108] In one particular embodiment, step c) of the method consists in polymerizing / crosslinking the emulsion obtained in step b) to obtain said porous bone substitute material. Advantageously, the polymerization / crosslinking is carried out in a mold to give the porous bone substitute material the desired shape. Advantageously, the emulsion obtained in step b) is kept at a temperature between 30°C and 80°C for a period of 10 to 30 hours. Advantageously, the emulsion obtained in step b) is kept at a temperature between 35°C and 65°C, advantageously at a temperature between 40°C and 60°C, advantageously at a temperature between 45°C and 65°C, advantageously at a temperature between 50°C and 60°C, advantageously at a temperature of 55°C. Advantageously, the emulsion obtained in step b) is left at a temperature between 30° C. and 80° C. for a period of 10 to 30 hours, advantageously 11 to 29 hours, advantageously 12 to 29 hours, advantageously 13 to 28 hours, advantageously 14 to 27 hours, advantageously 15 to 27 hours, advantageously 16 to 27 hours, advantageously 17 to 27 hours, advantageously 18 to 26 hours, advantageously 19 to 25 hours, advantageously 20 to 24 hours, advantageously 22 hours. Advantageously, the skilled person will be able to adapt the temperature depending on the pore size desired in the porous bone substitute material.

[0109] In one particular embodiment of the invention, the porous bone substitute material obtained in step c) is annealed prior to step d). Advantageously, the porous bone substitute material obtained in step c) is annealed at a temperature of at least 50°C for at least 1 hour. Advantageously, the porous bone substitute material obtained in step c) is annealed at a temperature of 100°C for 2 hours.

[0110] In a particular embodiment, the washing step of step d) makes it possible to remove the reagents necessary for the synthesis of the poly(ester-urea-urethane) that have not reacted during polymerization, as well as any surfactants and catalysts still present. Advantageously, the washing of step d) is carried out using dichloromethane, dichloromethane / hexane, hexane, water, a mixture of one of these products, or by successive application of these products. Advantageously, the washing of step d) is carried out by contacting the dried porous bone substitute material with dichloromethane for at least 24 hours, followed by a washing step with dichloromethane / hexane (50% by volume / 50% by volume) for at least 24 hours, followed by a washing step with hexane for at least 24 hours, and a final washing step with purified water for at least 24 hours.

[0111] In one particular embodiment, the method according to the invention may further comprise a drying step between steps c) and d). Advantageously, this drying step may be carried out by air drying or in an oven. A person skilled in the art will be able to adapt the oven temperature depending on the material to be dried. Advantageously, drying is carried out by air drying for at least 7 days.

[0112] In a particular embodiment, the drying of step e) can be carried out by air drying or in an oven. A person skilled in the art will be able to adapt the temperature of the oven depending on the material to be dried. Advantageously, drying is carried out by air drying for at least 15 days.

[0113] In one particular embodiment, the method according to the invention can further comprise a sterilization step f) after the washing step e) of the porous bone substitute material. In one particular embodiment, the sterilization step f) can be carried out directly on the dried porous bone substitute material or after vacuum washing of the biomaterial in an aqueous medium. Advantageously, sterilization is carried out after vacuum washing in an aqueous medium.

[0114] In one embodiment, the sterilization step f) is carried out as follows: f1) contacting the porous bone substitute material in sterile water under vacuum for 1 hour; f2) replacing the sterile water and contacting the porous bone substitute material in the replaced sterile water under vacuum for 4 hours; f3) contacting the porous bone substitute material from step f2) in 70% ethanol under vacuum for 1 hour; f4) replacing the 70% ethanol with sterile water and contacting the porous bone substitute material from step f3) in sterile water overnight under ambient pressure; f5) Sterilizing the porous bone substitute material from step f4) by autoclaving in water.

[0115] In another embodiment, the sterilization step f) may be carried out by gamma radiation. In another embodiment, the sterilization step f) may be carried out by beta radiation. Advantageously, the dose of beta and / or gamma radiation may be between 15 and 45 kGy. Advantageously, the dose of beta and / or gamma radiation is 25 kGy. Advantageously, the dose of beta and / or gamma radiation is 15 kGy.

[0116] In another embodiment, the sterilization step f) may be carried out by contacting the bone substitute material with ethylene oxide.

[0117] In another embodiment, the sterilization step f) may be carried out by contacting the bone substitute material with a plasma phase derived from a gas.

[0118] In another embodiment, the sterilization step f) can be performed by irradiating the bone substitute material with an electron beam (E-beam). The electron beam irradiation treatment has the following advantages: shorter treatment time, improved efficiency of the supply line, less risk of embrittlement of the elastomeric matrix, less oxidative damage within the bone substitute material, and no discoloration of the treated bone substitute material, making the bone substitute material clean and safe. Furthermore, the electron beam irradiation treatment is an ecological treatment.

[0119] In one particular embodiment, the method according to the invention may further comprise a step g) of storing said porous bone substitute material after the sterilization step e), which is advantageously carried out by contacting said porous bone substitute material in 70% ethanol until its use.

[0120] In one particular embodiment of the present invention, the method for preparing a porous bone substitute material comprises the following steps: a) preparing an organic phase containing the compounds necessary for the synthesis of poly(ester-urea-urethane); b) adding water and decellularized bone particles to the organic phase of step a) to form an emulsion; c) polymerizing / crosslinking the emulsion obtained in step b) to obtain said porous bone substitute material; d) washing the porous bone substitute material obtained in step c); e) drying the porous bone substitute material obtained in step d); f) sterilizing the porous bone substitute material resulting from step e); and g) Optionally, storing the porous bone substitute material.

[0121] In one particular embodiment of the present invention, the method for preparing a porous bone substitute material comprises the following steps: a) preparing an organic phase containing the compounds necessary for the synthesis of poly(ester-urea-urethane); b) simultaneously adding water and decellularized bone particles to the organic phase of step a) to form an emulsion; c) polymerizing / crosslinking the emulsion obtained in step b) to obtain said porous bone substitute material; d) washing the porous bone substitute material obtained in step c); e) drying the porous bone substitute material obtained in step d); f) sterilizing the porous bone substitute material resulting from step e); and g) Optionally, storing the porous bone substitute material.

[0122] In one highly advantageous embodiment of the present invention, the method for preparing a porous bone substitute material comprises the following steps: a) preparing an organic phase containing compounds necessary for the synthesis of poly(ester-urea-urethane), comprising a first step a1) consisting of solubilizing polycaprolactone triol oligomer and surfactant Span 80 in toluene, and then a second step a2) consisting of adding a crosslinker HMD1 and a catalyst DBTDL to the solution of step a1) to form an organic phase; b) adding water and decellularized bone particles to the organic phase of step a) to form an emulsion; c) polymerizing / crosslinking the emulsion obtained in step b) to obtain said porous bone substitute material; d) washing the porous bone substitute material obtained in step c); e) drying the porous bone substitute material obtained in step d) for at least 15 days; f) sterilizing the porous bone substitute material resulting from step e); and g) Optionally, storing the porous bone substitute material. [Brief explanation of the drawings]

[0123] [Figure 1]Figure 1 shows allogeneic bone granules homogeneously distributed within and on the surface of a porous bone substitute material according to the present invention. The images were obtained by 3D microscopy (VHX Keyence) of the porous bone substitute material according to the present invention after cleaning without staining of the bone granules, and the arrows indicate the presence of bone granules (A, B). [Figure 2] 1 shows Fourier transform infrared spectroscopy (FTIR) analysis of bone granules alone, poly(caprolactone-urea-urethane) elastomer matrix alone, and a porous bone substitute material (composite) according to the present invention. [Figure 3] 1 shows the stress-strain curves of the poly(caprolactone-urea-urethane) elastomer matrix alone and the porous bone substitute material (composite material) according to the present invention during compression testing (left: full curve; right: zoomed in on the beginning of the curve). [Figure 4] 1 shows the mass loss of a poly(caprolactone-urea-urethane) elastomeric matrix alone and a porous bone substitute material (composite) according to the present invention during in vitro degradation at 37° C. and accelerated in vitro degradation at 90° C. [Figure 5] Figure 1 shows the cell activity determined by MTT test after incubation in extraction medium of poly(caprolactone-urea-urethane) elastomer matrix alone and of the porous bone substitute material (composite) according to the present invention. "Blank" represents the results for control cells under normal conditions, while "positive control" represents the results for cells in the presence of a cytotoxic molecule (here chosen to be HMDI). [Figure 6] Figure 1 shows cell viability determined by trypan blue staining during indirect cytotoxicity testing of poly(caprolactone-urea-urethane) elastomer matrix alone and the porous bone substitute material (composite) according to the present invention. "Blank" represents the results for control cells under normal conditions, and "positive control" represents the results for cells in the presence of a cytotoxic molecule (here chosen to be HMDI). [Figure 7]FIG. 1 shows the migration of mesenchymal stromal cells obtained from canine adipose tissue from day 10 (J10) to day 40 (J40) within a poly(caprolactone-urea-urethane) elastomer matrix alone and within a porous bone substitute material (composite material) according to the present invention. [Figure 8] 1 depicts a critical size segmental defect on the femur of a rat. [Figure 9A] 1 depicts a cylinder of porous bone substitute material according to the present invention in conditioned medium prior to implantation. [Figure 9B] 1 represents a cylinder of porous bone substitute material according to the invention after acquisition by microtomography. [Figure 10A] 1 depicts radiological monitoring of a femoral segmental defect maintained by an osteosynthesis plate with partial reconstruction after 61 days. [Figure 10B] 1 depicts radiological monitoring of femoral segmental defects maintained by osteosynthesis plates with the appearance of system failure after 31 days. [Figure 11] Figure 1 shows the concentrations of red blood cells and platelets for the control (no surgery), blank control (empty defect), poly(caprolactone-urea-urethane) elastomer matrix alone (elastomer), bone substitute material according to the present invention (composite material), decellularized bone, and positive control (non-critical) lots at different study times. [Figure 12] The figures show the concentrations of leukocytes and lymphocytes for the control (no surgery), blank control (empty defect), poly(caprolactone-urea-urethane) elastomer matrix alone (elastomer), bone substitute material according to the present invention (composite material), decellularized bone, and positive control (non-critical) lots at different study times. [Figure 13] Figure 1 shows serum marker concentrations of bone metabolism (CTX: bone resorption; P1PN and Oc: bone synthesis) for lots including control (no surgery), empty control (empty defect), poly(caprolactone-urea-urethane) elastomer matrix alone (elastomer), bone substitute material according to the present invention (composite material), decellularized bone, and positive control (non-critical) at different study times. [Figure 14A] The figures show the amount of bone formed within the bone defect zone after 1 month or 3 months for lots including a control (no surgery), an empty control (empty defect), a poly(caprolactone-urea-urethane) elastomer matrix alone (elastomer), a bone substitute material according to the present invention (composite material), and a positive control (non-critical) at different study times. [Figure 14B] The figures show the bone volume / initial volume ratio of bone defects for the control (no surgery), empty control (empty defect), poly(caprolactone-urea-urethane) elastomer matrix alone (elastomer), bone substitute material according to the present invention (composite material), and positive control (non-critical) lots at different study times. [Figure 15A] The figure shows the surface area of ​​bone formed within the bone defect zone after 1 month or 3 months for lots including a control (no surgery), an empty control (empty defect), a poly(caprolactone-urea-urethane) elastomer matrix alone (elastomer), a bone substitute material according to the present invention (composite material), and a positive control (non-critical) at different study times. [Figure 15B] The figures show the bone surface / initial volume ratio of bone defects for lots including control (no surgery), empty control (empty defect), poly(caprolactone-urea-urethane) elastomer matrix alone (elastomer), bone substitute material according to the present invention (composite material), and positive control (non-critical) at different study times. [Figure 16] 1A and 1B show bone defects that remained empty after 3 months for the "control" lot ((A): 3D microtomography top view and (B): 3D microtomography lateral view). [Figure 17A] 3D microtomography top view after 3 months showing non-critical size bone defects for the "positive control" lot. [Figure 17B] 3D microtomography lateral view after 3 months showing non-critical size bone defects for the "positive control" lot. [Figure 17C]Histological cross-section with Masson's trichrome staining shows a non-critical size bone defect for the "positive control" lot after one month (magnification 5x). [Figure 17D] Detail of the central zone of the bone defect for the "positive control" lot (image insert C, 40x magnification). [Figure 18A] 3D microtomography top view after 1 month showing critical size bone defect for poly(caprolactone-urea-urethane) elastomer matrix lot alone. [Figure 18B] 3D microtomography top view after 3 months showing critical size bone defect for poly(caprolactone-urea-urethane) elastomer matrix lot alone. [Figure 18C] 1 shows a critical size bone defect for a poly(caprolactone-urea-urethane) elastomer matrix single lot in histological cross section with Sudan Black staining after 1 month (magnification 2.5x). [Figure 18D] Detail of the central zone of the bone defect for the poly(caprolactone-urea-urethane) elastomer matrix alone lot with Masson's trichrome staining after 1 month (image insert C, 40x magnification). [Figure 19] 1 shows the bone defect after 3 months for a poly(caprolactone-urea-urethane) elastomer matrix lot alone ((A): 2D microtomography lateral view), (B): 3D microtomography lateral view, and (C): 3D microtomography inferior view). [Figure 20] 3D microtomography lateral view showing the bone defect after 3 months for the "Decellularized Bone" lot. [Figure 21A] 3D microtomography top view after one month showing a critical size bone defect for a "composite" lot of porous bone substitute material according to the present invention. [Figure 21B] 3D microtomography top view after 3 months showing critical size bone defects for the porous bone substitute material "composite" lot according to the present invention. [Figure 21C] 1 shows a histological cross section with Masson's Trichrome staining of a critical size bone defect for a "composite" lot of porous bone substitute material according to the invention after one month (magnification 2.5x). [Figure 21D] 1 shows a detail of the central zone of a bone defect for a "composite" lot of porous bone substitute material according to the invention (image insert C, 40x magnification). [Figure 21E] 1 shows a histological cross section with Masson's Trichrome staining of a non-critical size bone defect for a "composite" lot of porous bone substitute material according to the present invention after one month (magnification 2.5x). [Figure 21F] 1 shows a detail of the outer zone of the bone defect for a "composite" lot of porous bone substitute material according to the invention (image insert C, 40x magnification). DETAILED DESCRIPTION OF THE INVENTION

[0124] Example 1: Preparation and synthesis of porous bone substitute material according to the present invention In the first step, the allogeneic material Allodyn® (decellularized bone) was milled to produce granules with diameters of 50-500 μm. To obtain particles of controlled size, the granule mixture obtained after milling was sieved using a continuous sieve shaker (Fisher AS200 TAP). This allowed the granules to be separated according to particle size: 50-100 μm, 100-200 μm, 200-300 μm, and 300-400 μm. Granules with sizes greater than 400 μm were not selected here.

[0125] In the second step, these granules were incorporated into an elastomeric matrix containing a poly(caprolactone-urea-urethane)-based elastomer during synthesis by the poly-HIPE method (formation of a high internal phase emulsion and polymerization / crosslinking).Several elastomeric matrix / allogeneic bone ratios were tested.

[0126] These steps were validated for the human-derived decellularized allogeneic bone source Allodyn®. As available in sufficient quantities during the study, the bovine-derived xenogeneic decellularized bone source Laddec® was also tested, and no variations were observed.

[0127] The selected compositions are as follows: - Bone substitute material A with a 100% elastomeric matrix / allogeneic bone (1 g / 1 g) ratio, i.e., a 50% bone mass fraction and a particle size of 300-400 μm; - Bone substitute material B with a 50% elastomeric matrix / allogeneic bone (1 g / 0.5 g) ratio, i.e., a bone mass fraction of 33% and a particle size of 300-400 μm.

[0128] A bone fraction greater than 50% causes structural loss of the bone substitute material.

[0129] Example 2: Physicochemical and mechanical properties of the bone substitute material according to the invention The physicochemical properties of the bone substitute material according to the present invention were tested by the following methods: - Fourier transform infrared spectroscopy (FTIR) for the analysis of chemical functional groups present in the synthesized substitute materials; - Scanning electron microscopy (SEM) for morphological observation of the substitute materials, coupled with elemental analysis (EDX); - Volumetric absorption measurements to determine the degree of interconnectivity of porous structures; - Alizarin red staining to assess and visualize the incorporation of allogeneic bone particles within the substitute material. This dye is a specific marker of calcium volume.

[0130] For clarity, the results detailed below are shown for bone substitute material B, which has a bone mass fraction of 33% and contains bone particles with diameters of 300–400 μm.

[0131] 1. Interconnectivity / Porosity After washing, the density of the bone substitute material was assessed by pycnometry. The found value of 1.29, compared with the values ​​for matrix alone (1.05) or bone alone (2.59), indicates that bone particles are consistently present in the elastomeric matrix. A mass fraction of 31% was again found after washing, compared with the 33% mass fraction initially introduced into the emulsion. The decellularized bone particles appear to be homogeneously distributed within and on the surface of the bone substitute material (Figure 1). Furthermore, volumetric absorption measurements indicated that the interconnectivity of the porous structure was only slightly modified by the incorporation of bone particles, remaining above 80%. This value is consistent with good fluid penetration and cell migration (r = 100.8 ± 8% for the poly(caprolactone-urea-urethane) elastomeric matrix alone vs. r = 86.4 ± 2% for the composite).

[0132] 2. Chemical composition EDX (Table 1) and FTIR (Figure 2) analyses confirm the presence of calcium and phosphorus resulting from decellularized bone particles in the porous bone substitute material.

[0133] [Table 1]

[0134] Elemental analysis shows a good correlation between the theoretical values ​​expected depending on the amount of bone incorporated during the synthesis of the material and the experimental values ​​of the material after washing, once again proving the presence of bone particles in the elastomeric matrix.

[0135] The chemical structure of the elastomer matrix was not altered, since all peaks associated with this matrix were found again (Figure 2).

[0136] 2.3. Mechanical properties For the study of mechanical properties, it was necessary to fabricate samples with a larger diameter and verify the effectiveness of the synthesis steps. When this was completed, the properties of the bone substitute material according to the present invention and the elastomer alone of the poly(caprolactone-urea-urethane) elastomer matrix were clarified by mechanical compression tests. The shape of the stress-strain curve of the bone substitute material according to the present invention is similar to the shape of the curve of the poly(caprolactone-urea-urethane) elastomer matrix alone, demonstrating the elastomeric properties of the material (Figure 3).

[0137] The Young's modulus E of the porous material can be defined on the first linear part of the curve. For the bone substitute material according to the present invention, a value of 228 kPa was found, which falls within the range of elastomeric foams (1 < E < 1000 kPa). In the second linear part of the curve, the Young's modulus E of the non-porous material when all pores are crushed can be defined. For the bone substitute material according to the present invention, a value of 19 MPa was found. The value is higher than the value found for the poly(caprolactone-urea-urethane) elastomer matrix alone. Therefore, the decellularized bone particles contribute to a slight increase in the coefficient of the bone substitute material according to the present invention while maintaining the elastomeric properties of the polymer matrix.

[0138] 2.4. Reaction rate of degradation An important criterion when creating a bone substitute material for tissue engineering is its absorbability, since it must be replaced by new bone over time. It has been suggested that for bone tissue regeneration, the bone substitute material must have low hydrophilicity so that the degradation rate can exceed 18 months. The study of degradation in vitro was carried out in accordance with the ISO 10993-13 standard. In particular, the reaction rate of degradation was evaluated by measuring the mass loss. The accelerated degradation test at 90 °C showed that the bone substitute material degrades slightly faster than the poly(caprolactone-urea-urethane) elastomer matrix alone (Figure 4). This is due to an increase in the hydrophilicity of the material, as proven by water contact angle measurements: namely θ = 121 ± 10° for poly(caprolactone-urea-urethane) elastomer matrix alone versus θ = 83 ± 22° for bone substitute material

[0139] Thus, poly(caprolactone-urea-urethane) elastomer matrices alone are stable for 14 days at 90°C. By applying the "rule of 10," which describes the relationship between the increase in degradation rate per 10°C increase in temperature and the Q10 factor of 2 to 2.5 [ASTM F1980-02: Standard Guide for Accelerated Aging of Sterile Medical Device Packages], the lifetime of poly(caprolactone-urea-urethane) elastomer matrices alone at 37°C is estimated to be 19.4 to 63.4 months.

[0140] For bone substitute materials, the shelf life at 90°C is 10 days, which leads to an estimated shelf life of 13.0 to 42.3 months at 37°C. This stability is appropriate for the use of bone substitute materials as supports for bone regeneration.

[0141] Example 3: Interaction between porous bone substitute material according to the present invention and mesenchymal stromal cells obtained from canine adipose tissue (CSM) 3.1. Cytotoxicity test In a first step, the cytotoxicity of the extracts optionally salted out by the bone substitute material according to the invention was studied according to the ISO 10993-5 and 10993-12 standards.

[0142] Therefore, the bone substitute material obtained in Example 1 and the poly(caprolactone-urea-urethane) elastomer matrix alone are incubated in standard culture medium at 37°C for 24 hours. Then, this extract medium is deposited on the CSM mat at 80% confluence. After 24 hours of incubation, the metabolic activity of the cells is measured by the MTT test.

[0143] The results are presented in (Figure 5).

[0144] The standard specifies a cell viability limit of 70% for a product to be considered non-cytotoxic.

[0145] The results showed no difference in metabolic activity between control cells and cells placed in the presence of an extract medium containing either a poly(caprolactone-urea-urethane) elastomer matrix alone or the bone substitute material (composite material) according to the present invention. This metabolic activity was greater than 90%, thus exceeding the limits set by the standard. These results demonstrate the absence of cytotoxicity of the material extract under these conditions. In a second step, we evaluated the effect of the release of cytotoxic by-products by an indirect cytotoxicity test. For this, the material was deposited on CSM at 80% confluence without direct contact. After 24 hours of incubation at 37°C, cell viability was measured by trypan blue staining.

[0146] The results are presented in (Figure 6).

[0147] The resulting cell viability was greater than 80%, comparable between the control and cells placed in the presence of poly(caprolactone-urea-urethane) elastomeric matrix alone or in the presence of the bone substitute material (composite) of the present invention. The indirect cell-scaffold interaction did not produce cytotoxic compounds in the medium after 24 hours.

[0148] 3.2. Interaction of CSM cells with bone substitute materials To test the "attractive" ability of the bone substitute material (composite material) of the present invention and the poly(caprolactone-urea-urethane) elastomer matrix alone, a colonization test was performed using canine CSM. The bone substitute material (composite material) of the present invention and the poly(caprolactone-urea-urethane) elastomer matrix alone were each deposited onto a CSM mat at 80% confluence. Cell migration was determined after 10, 20, 30, and 40 days.

[0149] The results are presented in (Figure 7).

[0150] The cells present on and within the bone substitute material (composite material) of the present invention and the poly(caprolactone-urea-urethane) elastomer matrix alone were counted after enzymatic cell detachment, and the results indicated that the cells had the ability to migrate within the material.

[0151] Conclusion: All these results demonstrate that the bone substitute material (composite material) according to the invention is not toxic, that cells have the ability to attach and proliferate thereon, and that cells are able to colonize the material even at depth, regardless of the culture conditions, demonstrating its osteoconductive properties.

[0152] Example 4: In vivo study of the repair ability of bone substitute materials (composites) on a rat model of segmental defects This study involved the reconstruction of segmental bone defects in rats (male Lewis rats, 7-9 weeks old, 1 month old). This type of lesion is similar to those frequently encountered in military or civilian victims of terrorist attacks or traffic accidents, making it possible to evaluate the biocompatibility, biodegradability, and efficacy of biomaterials in real-world conditions.

[0153] The segmental bone defect model consists of removing a bone fragment that eliminates any continuity between two adjacent bone segments and does not allow for spontaneous repair. The critical size of this bone defect is defined as being equal to (at least) 1.5-2 times the diameter of the target bone.

[0154] To evaluate the effectiveness of the bone substitute material (composite) of the present invention compared with poly(caprolactone-urea-urethane) elastomer matrix alone, multiple animal lots were monitored up to 3 months after the lesion / implantation. The effectiveness of bone repair was evaluated by microtomography and histology of femurs harvested after euthanasia. Animal blood was used for blood count / preparation and ELISA assays (for serum) of markers of bone formation and resorption.

[0155] Lots of 6 animals were used for each time point, 1 month and 3 months, for a total of 60 animals. The right femur was operated on and the left femur was used as a reference. "Control" lot: empty defect, no implant. "Poly(caprolactone-urea-urethane) elastomer matrix only" lot Bone substitute material (composite material) lot according to the present invention (33% bone, 300-400 μm granules) "Positive control" lot: non-critical size defects (blank control) "Control lots" (no surgery) correspond to animals that were not operated on but were subjected to anesthesia and analgesia.

[0156] The rat model of segmental bone defects consists of performing a cut within the femoral shaft that does not allow any spontaneous repair. The critical size of this bone defect is 5-6 mm, a well-established length in this rodent model. The bone is cut at the shaft, and the two epiphysis are stabilized with a fixture adapted to the rat femur (Figure 8). The fixture is held on the upper surface of the femur by four 1.1 mm diameter stainless steel screws (Synthes).

[0157] 5.1 Surgical procedures Anesthesia / Analgesia: Anesthesia: Ketamine / Medetomidine: 60 / 0.5mg / kg administered internally parenterally. Arousal: Atipamezole, 1 mg / kg intramuscularly. Analgesia: Buprenorphine 0.05 mg / kg subcutaneously (SC) postoperatively (awakening, then 3 times daily for 3 days).

[0158] Surgical procedure: Shaving of the hind legs and back; disinfection with Betadine; identification of the external surface of the operated thigh; Incision (20-30 mm) of the skin and external aponeurosis and retraction using surgical scissors with rounded tips on the muscle plane to expose the central part (shaft) of the femur free of vascular lesions; Placement of a fixation device (steel plate or PEEK, L = 23 mm) that is maintained on the upper surface of the femur using a needle holder; Drilling of holes (1 mm diameter drill) to accommodate the screws under continuous saline irrigation; placement of four transcortical screws; · Transverse cutting of the bone with an oscillating saw (ConMed) and removal of the bone segment (Fig. 11), the interior of the hole is cleaned by careful injection of saline solution; · Placement of implants into bone defects; Approximation of muscle planes. If necessary, add 2-3 separate sutures (absorbable sutures). Closure of skin planes with 5mm staples; · Topical application of Betadine; Awakening, placing the animal in a lateral position on a dry sheet in its cage on a hot plate; Post-operative care: Subcutaneous analgesia during wakefulness and for three days thereafter (three times daily).

[0159] The animals use the operated limb immediately after waking up. The animals are monitored daily: the wound is clean and, if the osteosynthesis system is stable, no external signs of inflammation or changes in behavior or lameness are noted. The weight curves are similar for all lots during the study, with a recovery phase of approximately 15 days after surgery.

[0160] 5.2 Implant preparation The biomaterials (bone substitute material (composite) according to the present invention and poly(caprolactone-urea-urethane) elastomer matrix alone) were cylindrical, 10-15 mm long and 4 mm in diameter (Figure 9A). They were prepared in sterile conditions in conditioned medium the day before implantation and incubated in an oven at 37°C and 5% CO2. They were cut to the appropriate dimensions for each animal before placement within the bone defect. Several composite lots were scanned by microtomography to confirm the size and homogeneity of the granular repair prior to implantation (Figure 9B).

[0161] The conditioned medium used contains DMEM (Dulbecco's Modified Eagle's Medium); penicillin / streptomycin 0.8%; and fungizone 1%.

[0162] The biomaterial does not fracture and maintains its integrity upon implantation.

[0163] Two types of biomaterials, the poly(caprolactone-urea-urethane) elastomeric matrix alone and the porous bone substitute material (composite) of the present invention, are considered radiolucent, which allows visualization of newly synthesized bone and thus easier radiological monitoring.

[0164] Only the Laddec® granules within the composite are radiopaque and localizable by microtomography (FIG. 9B).

[0165] 5.3 Radiation monitoring Radiation monitoring is performed using an irradiation device (SARRP) in imaging mode on days 1, 3, 6, and 12, and then every 10–15 days. This allows us to confirm the integrity of the osteosynthesis system and the appearance of mineralized bone inside the bone defect (Figure 10A). If the osteosynthesis system fails, as exemplified by the most distal viscus becoming detached after 31 days (Figure 10B), the animal is euthanized and the femur is collected for analysis.

[0166] Quantitative analysis of the images shows no bone formation up to one month after surgery. At three months, more or less large calluses are visible within the defect, restoring continuity between the two segments in half of the animals in the "bone substitute material (composite material) of the present invention" group.

[0167] 5.4. Blood Quantitation Assays Prior to sacrifice, anesthetized rats were bled by intracardiac puncture onto EDTA-K3 for blood cell counts (Procyte DX-IDEXX veterinary hematology equipment) to detect any abnormal inflammation or incidental effects of the biomaterial on the blood picture. Serum was also prepared from the collected blood without anticoagulants and centrifuged at 1500 g for 10 min for quantitative assay of bone repair markers by ELISA test.

[0168] At the red blood cell level, production remains greater at 1 and 3 months compared to unoperated animals, but no significant variations were detected between lots and over time. Platelet concentrations remain stable (Figure 11).

[0169] Global inflammation levels were similar for all lots (Figure 12), similar to the basal levels in unoperated rats, and no significant differences were noted. Thus, the poly(caprolactone-urea-urethane) elastomer matrix alone or the bone substitute material (composite material) of the present invention is well tolerated by the body and does not amplify the inflammatory response resulting from bone trauma at these late times in this rat model.

[0170] Direct markers of remodeling (Figure 13) demonstrate synthetic activity (Oc, P1NP) and bone resorption (CTX1). However, the interpretation of these quantitative assays is difficult in animals, since their levels are dependent, for example, on the day / night cycle. The values ​​observed for P1NP (the N-terminal propeptide of type 1 procollagen) rather reflect the proliferative phase of osteoblasts. These values ​​are here four to five times lower than those of unoperated animals (53.20 ± 2.89 ng / mL). Nevertheless, a value twice as high (25.52 ± 11.34 ng / mL) is noted for the decellularized bone lot at 3 months.

[0171] The concentration of osteocalcin (OC), a serum marker of bone synthesis (representing mineralization activity by osteoblasts), remained lower for all lots at 1 and 3 months than that of unoperated rats (1031.35 ± 59.06 ng / mL). However, the values ​​at 3 months for the lots implanted with the different biomaterials were found to be similar to those again observed for the positive control, in which complete remodeling was underway (625.65 ± 41.15 ng / mL). These values ​​were three times higher than those observed for the control lot (empty defect), in which no remodeling was observed (221.40 ± 19.50 ng / mL).

[0172] These overall values ​​likely represent the high osteoblast activity produced when the biomaterial was placed, even though they remain lower than those seen in unoperated animals. CTX1 (the carboxy-terminal telopeptide of type 1 collagen) is a marker of bone resorption via the cathepsin K pathway, a major pathway for bone remodeling. When the bone defect remained empty (7.89 ± 0.87 ng / mL), the concentration was lower than that in unoperated animals (9.24 ± 0.52 ng / mL), reflecting low remodeling activity associated with low bone tissue neosynthesis. This concentration was equivalent to that in unoperated animals when poly(caprolactone-urea-urethane) elastomer matrix alone, the porous bone substitute material (composite material) of the present invention, or decellularized bone was implanted at 1 and 3 months, indicating ongoing remodeling of newly formed mineralized tissue.

[0173] 5.5. Microtomography analysis While the femurs were fixed in Burckhardt's solution for subsequent histological analysis, they were analyzed by microtomography (Skyscan 1174) at 50 kV and 800 μA to visualize and quantify bone neomineralization at the segmental defects. A rapid acquisition (40–70 min) was performed on the intact femurs using the fixator at a resolution of 50–60 μm. Depending on the mineralization level and the "solidity" observed at the time of acquisition, the fixator was then removed and a finer acquisition (14–20 μm resolution, 2–3 h) was performed for analysis. The measurement zone corresponded to the zone of the initial bone defect.

[0174] The collected data are processed by quantification software (CTan, Skyscan), which makes it possible to visualize and quantify the bone remodeling at the bone defect by the BV / TV ratio (bone volume / tissue volume), which represents the amount of newly formed bone within a given volume.

[0175] Figure 14A allows the quantification of the bone present within the zone of the bone defect. This zone is larger than that of unoperated animals (31.11 mm) when the defect is left empty. 3 ) for control animals at 1 month as well as 3 months, indicating the absence of bone synthesis and therefore repair in this model. When poly(caprolactone-urea-urethane) elastomer matrix alone is implanted, this value is 10.8 ± 1.1 mm at 1 month compared to that of control animals (10.8 ± 1.1 mm). 3 ) but after 3 months it was equivalent to the value of unoperated animals (24.75 ± 7.29 mm 3 ) is equivalent to

[0176] The implantation of the bone substitute material (composite material) of the present invention resulted in a bone mass formed at 3 months (68.60 ± 26.02 mm), which was 2.5 times greater than the bone mass of unoperated animals. 3 ) which appears as the result of the synthesis being three times larger here (80.03 ± 23.99 mm 3 ) close to the values ​​seen for the positive control.

[0177] However, if this amount of formed bone is replaced by the initial volume of the defect zone (Figure 14B), the overall value obtained for all lots is lower than that found for non-operated animals (41.1). This value represents the proportion of bone within a defined zone and may allow one to recognize the stage of the ongoing repair process. In fact, bone repair involves an active synthesis phase followed by a more or less prolonged callus remodeling phase. During this remodeling phase, the bone is repaired and reorganized according to the zone of the bone in question, in this case the cortical bone, to allow the restoration of mechanical properties.

[0178] The mirror image of the ratio of bone surface (BS) to bone defect volume (BV) (BS / BV) represents the structural level of the formed bone (Figures 15A and 15B). For control animals, a high ratio (15.10 ± 5.49 mm) was observed. -1) represents a rather finely spread mineralized structure, whereas for the positive control, lower values ​​represent a more compact bone (5.26 ± 0.36 mm -1 At 3 months, the poly(caprolactone-urea-urethane) elastomer matrix alone (7.82±1.65 mm -1 ) and the bone substitute material (composite material) according to the present invention (6.99±2.09 mm -1 ), the intermediate values ​​again found indicate that the produced bone is in the process of remodeling to regain a more compact structure.

[0179] 5.6. Histology All data obtained by microtomography are correlated with the regional information obtained by histological analysis, performed consecutively on the same specimens. The harvested femurs are fixed in Burckhardt's solution and embedded in MMA (methyl methacrylate) resin adapted for hard tissues.

[0180] Afterwards, thick sections (avoiding tearing of the biomaterial) were stained with stains specific for different cell types: - Masson's Trichrome™ stains mineralized tissue blue, revealing the cells responsible for formation, i.e., osteoblasts, and bone remodeling, i.e., osteoclasts, as well as the osteoid zone of mineralization (pink) and vasculature. - Sudan Black (NS) dyes poly(caprolactone-urea-urethane) elastomer matrices black. - Sirius Red (RS) stains collagen fibers red under light microscopy and yellow / orange under polarized light, making it possible to visualize the level of structuring in tissues.

[0181] 5.7. Lot-by-lot results 5.7.1. "Control" Lot The results obtained are presented in FIG.

[0182] The bone defects remain empty, and no remodeling has been observed within the defects over the 3-month study period (Figure 16). Bone forms only at the edges, with signs of bone synthesis observed under the fixture in some animals (Figure 16). The defects are filled with fibrous tissue, confirming the critical size of the bone defects.

[0183] 5.7.2. "Positive Control" Lot The size of the bone defect is not critical here and is representative of a simple fracture. After 3 months, when this size is approximately 2 mm, virtually complete reconstruction is observed (Fig. 17A). Perhaps related to a certain "elasticity" of the system, a highly active mineralization zone, indicated by the arrow in Fig. 17C, is found at the bone margin after 1 month, and an endochondral ossification zone is again found in the center of the defect (Fig. 17D). Indeed, the rats are active and active, and this zone is subjected to great mechanical stresses.

[0184] In Figure 17B, when the defect size is less than 1 mm (only sawtooth lines), complete repair can be observed with restoration of bone continuity after 3 months.

[0185] The results obtained are presented in Figures 17A-17D.

[0186] 5.7.3. "Poly(caprolactone-urea-urethane) elastomer matrix only" lot The level of regeneration was low 1 month after implantation (Figure 18A) and localized only at the bone margins, however, Sudan Black staining allowed visualization of the poly(caprolactone-urea-urethane) elastomer matrix alone in the center of the defect and integrated into the neosynthetic bone (Figure 18C).

[0187] It can be noted that the poly(caprolactone-urea-urethane) elastomer matrix alone underwent macroscopic structural modifications. That is, the cancellous tissue "flattened and expanded," as observed in previous studies within cavitary defects at 1 month. Masson's trichrome staining allowed visualization of numerous osteoid zones (Figure 18D, indicated by arrows) (corresponding to zones of mineralization by osteoblasts) around this area, which was tightly integrated into the bone. Furthermore, biomaterial was visible within the poly(caprolactone-urea-urethane) elastomer matrix alone, revealing the preservation of the porosity of this biomaterial.

[0188] The 3D reconstruction obtained after 3 months (Figure 18B) reveals partial reconstruction of the defect, with continuity largely restored. The osteoinductive properties of poly(caprolactone-urea-urethane) elastomer matrix alone, previously demonstrated for the cavitary bone defect model, are clearly rediscovered.

[0189] However, we noted in some specimens the distinctive trabecular structure of newly formed bone within the defect in the presence of poly(caprolactone-urea-urethane) elastomeric matrix alone (Figure 19). Furthermore, at the edge of the fixture, a small amount of bone synthesis was observed that appeared to be "backed" by the fixture, which is located by the arrow in Figure 19.

[0190] 5.7.4. Decellularized Bone Lot To confirm biocompatibility and osteoconductive properties, a 2 mm diameter cylindrical Allodyn® rod was filled into the bone defect. The implant was carefully cut at the time of placement so that it completely filled the defect and was in contact with the two bone margins. After 3 months, no reconstruction was observed (Figure 20). Signs of biomaterial resorption were noted. In some specimens, moderate bone synthesis was observed around the edges of the fixture (outside the reconstructed zone), at a level similar to that seen with the poly(caprolactone-urea-urethane) elastomer matrix alone. No rejection or infection was recorded.

[0191] 5.7.5. Lots of "Bone Substitute Material of the Present Invention" The remodeling process was modified by incorporating decellularized bone in the form of granules within a poly(caprolactone-urea-urethane) elastomer matrix. Indeed, bone formation on the bone margins was evident after 1 month, as evidenced by Masson's trichrome staining, along with a rich osteoid zone at this level (Figures 21C and 21D). However, the bone defect zone always appeared empty; decellularized bone granules were abundant and more or less eccentrically clustered relative to this zone (Figure 21A). Nevertheless, a "delocalized" focal bone synthesis was noted, with the fixator covered by a mineralized layer. This became even more pronounced after 3 months (Figure 21B), with the fixator completely covered by bone on its distal and proximal ends. Bone synthesis was focal at this time point, and the defect zone was largely repaired. In half of the animals, continuity was restored, and the defect was largely filled with mineralized tissue. Histological analysis will allow confirmation of the structure of this newly formed bone and its level of remodeling.

[0192] In some samples, mineralized granules were again found completely outside the zone to be reconstructed, sandwiched between bone tissue and surrounding muscle. Again, histological analysis will allow us to state whether they are residual granules of decellularized bone that have flowed outside the defect zone without being absorbed, or whether they represent an external source of mineralization.

[0193] Indeed, on some histological sections, the presence of more or less diffuse zones of mineralization located outside the bone defect can already be seen from 1 month onwards (Figures 21E and 21F).

[0194] Conclusion: Bone formation generally occurs around biomaterials and, to a smaller extent, inside these biomaterials. The multi-scale porosity of the porous bone substitute material according to the present invention appears to be a positive factor, since multiple ossification sources were detected inside this material, highlighting the fact that differentiated and active cells, possibly accompanied by blood vessels, could migrate into this zone.

[0195] These histological analyses also allowed visualization of the porous bone substitute material of the present invention within the bone defect; the bone material appeared fragmented and partially contained within mineralized tissue, demonstrating that degradation and biointegration were compatible with the kinetics of repair. The estimated in vivo lifespan of the porous bone substitute material of the present invention is 13-42 months, a lifespan compatible with clinical use.

[0196] Histological analysis confirms the osteoconductivity and degradation of the porous bone substitute material according to the invention visible within the first month after implantation.

[0197] Overall, the results demonstrate that the porous bone substitute material of the present invention possesses excellent mechanical properties, excellent biocompatibility, and degradation adapted to bone tissue reconstruction. This material exhibits advantageous in vivo performance by inducing intensive bone synthesis until tissue continuity between the two bone fragments is restored. The presence of decellularized bone in the porous bone substitute material of the present invention increased the production of mineralized tissue, which was three-fold greater than that obtained with the poly(caprolactone-urea-urethane) elastomer matrix alone after three months. However, this intensive production was not solely localized within the bone defect but also occurred around the fixation device. Multiple mineralized zones were detected between the bone tissue and the surrounding muscle.

Claims

1. In porous bone substitute materials: at least one elastomeric matrix, - decellularized bone particles, 1. A porous bone substitute material comprising:

2. 2. The porous bone substitute material of claim 1, wherein the at least one elastomeric matrix comprises a poly(ester-urea-urethane) based elastomer, and the ester is selected from among caprolactone oligomer (PCL), lactic acid oligomer (PLA), glycolic acid oligomer (PGA), hydroxybutyric acid oligomer (PHB), hydroxyvaleric acid oligomer (PVB), dioxanone oligomer (PDO), poly(ethylene adipate) oligomer (PEA), poly(butylene adipate) oligomer (PBA), or a combination thereof.

3. 3. The porous bone substitute material according to claim 1 or 2, characterized in that the decellularized bone particles are obtained from natural bone.

4. 4. The porous bone substitute material according to claim 1, wherein the decellularized bone particles have a diameter of 1 nm to 1 mm.

5. 5. The porous bone substitute material according to claim 1, wherein the decellularized bone particles comprise at least 10% by weight of the porous bone substitute material.

6. The porous bone substitute material according to any one of claims 1 to 5, characterized in that the porous bone substitute material has a multi-scale pore size of 50 μm to 2000 μm.

7. 7. The porous bone substitute material according to claim 1, wherein the porous bone substitute material has a total porosity of 60% or more.

8. The porous bone substitute material has a thickness of 0.1 to 400 cm ３ 8. Porous bone substitute material according to claim 1, characterized in that it has a volume of 0.01g / cm2.

9. 9. A porous bone substitute material according to any one of claims 1 to 8 for use in bone repair.

10. 10. The porous bone substitute material of claim 9, wherein the bone repair is 5% or more by volume of the volume of the bone to be repaired.

11. A bone repair kit comprising a porous bone substitute material according to any one of claims 1 to 8 and a fastener.

12. A method for preparing a porous bone substitute material comprising: a) preparing an organic phase containing the compounds necessary for the synthesis of poly(ester-urea-urethane); b) adding water and decellularized bone particles to the organic phase of step a) to form an emulsion; c) polymerizing / crosslinking the emulsion obtained in step b) to obtain said porous bone substitute material; d) washing the porous bone substitute material obtained in step c); e) drying the porous bone substitute material obtained in step d); A method comprising:

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