Use of monomethyl dipropylene glycol ether to purify a biomaterial

Abstract

The present invention relates to the use of a particular agent, monomethyl dipropylene glycol ether, to purify a biomaterial, a purification method employing monomethyl dipropylene glycol ether, and a biomaterial obtained from said purification method.

Description

Title of the invention: Use of monomethyl dipropylene glycol ether to purify a biomaterial. Technical field

[0001] The present invention relates to the field of biomaterial purification. In particular, the invention relates to the use of a particular agent, monomethyl dipropylene glycol ether, to purify a biomaterial, a purification method employing monomethyl dipropylene glycol ether, and a purified biomaterial obtained from said method. State of the art

[0002] Biomaterials are synthetic or living materials designed to be implanted in a living organism to replace a part or function of an organ or tissue.

[0003] Used in many therapeutic areas, biomaterials offer many advantages but also many challenges, particularly in terms of the risk of adverse reactions or complications.

[0004] To avoid these risks, legislators have put in place strict regulations, involving control of the composition of biomaterials. More specifically, the regulations aim to control the purity of biomaterials in order to ensure their biocompatibility and effectiveness.

[0005] Thus, before considering the use of a biomaterial, it is necessary for manufacturers to control the purity of the biomaterial so that it is well tolerated by the recipient, with a limited risk of infection, inflammation or rejection reaction.

[0006] Purity control is a critical step in the production of biomaterials. To standardize the quality of biomaterials, regulations define tolerance thresholds to be respected, particularly with regard to the control of pyrogenic molecules.

[0007] Pyrogenic molecules are molecules that can cause an increase in body temperature when their concentration is too high. The predominant pyrogenic molecules in biomaterial manufacturing processes are bacterial endotoxins.

[0008] Endotoxins are toxins located in the outer membrane of certain Gram-negative bacteria. These toxins consist mainly of proteins, phospholipids, and lipopolysaccharides (LPS). Ubiquitous in nature, heat-stable, and small enough to pass through conventional sterilization filters, endotoxins are particularly difficult to eliminate.

[0009] Lipids of exogenous origin, such as bacterial lipids, are also considered undesirable molecules in a biomaterial. Similar to endotoxins, specific thresholds are established by regulations limiting their presence in biomaterials to enable their use in humans or animals.

[0010] As an example, the US Pharmacopoeia (USP 41 NF 36 monograph) defines a threshold of residual lipids between 0% and 1.5% on dermal matrices of bovine origin.

[0011] To meet the standards established by regulations, manufacturers develop and research purification processes. However, these processes are not suitable for the depyrogenation of biomaterials, that is to say, the reduction of the content of pyrogenic molecules.

[0012] For example, sterilization processes aim to inactivate microorganisms on or in biomaterials, but do not target pyrogenic molecules, particularly endotoxins. Consequently, they are not suitable for reducing the pyrogenic molecule content of biomaterials.

[0013] Other processes described in the prior art make it possible to avoid contamination by pyrogenic molecules, in particular by endotoxins such as: a) manufacturing techniques for biomaterials that prevent or control contamination by endotoxins, by avoiding, for example, the use of gram-negative bacteria; b) depyrogenation techniques by inactivation of endotoxins, in particular via the use of heat treatments or the use of ozone; or c) techniques for the physical elimination of endotoxins, including rinsing, distillation or ultrafiltration steps.

[0014] The application of so-called “clean” biomaterial manufacturing techniques does not guarantee the elimination of pyrogenic molecules. Although these methods are suitable for the production of medicinal products, their implementation can be more complex and often more costly for medical devices, particularly biomaterials, due to the specific nature of these devices.

[0015] Current deryogenization techniques such as heat treatment, while effective, are not suitable for biomaterials. On the one hand, biomaterials such as biological matrices are sensitive to heat. On the other hand, ozonation contributes to the formation of potentially undesirable by-products, has variable effectiveness, and is too costly to implement.

[0016] Physical elimination methods, on the other hand, have low effectiveness and cannot always replace the depyrogenation method.

[0017] Thus, the methods described in the prior art for eliminating or inactivating pyrogenic elements and / or lipids of exogenous origin are not suitable, too complex and often expensive to implement.

[0018] There is therefore a need for an alternative solution to purify a biomaterial in order to reduce the content of endotoxins and lipids, in particular bacterial lipids, suitable for all types of biomaterials, including biological matrices and polymers. Summary of the invention

[0019] To meet this need, the invention proposes the use of a particular agent to purify a biomaterial, said agent being monomethyl dipropylene glycol ether or one of its derivatives.

[0020] Monomethyl dipropylene glycol ether, CAS number 34590-94-8, is a neutral, transparent, slightly volatile solvent that is miscible with water. Primarily known for its use as a degreaser, monomethyl dipropylene glycol ether is also used as a solvent in printing inks.

[0021] Monomethyl dipropylene glycol ether is not subject to REACH classification (European Regulation No. 1907 / 2006) and exhibits low toxicity.

[0022] Advantageously, monomethyl dipropylene glycol ether or one of its derivatives makes it possible to purify biomaterials, preferably by reducing the content of at least one pyrogenic molecule of the biomaterial.

[0023] The inventors have discovered, surprisingly, that monomethyl dipropylene glycol ether or one of its derivatives is capable of purifying all types of biomaterials.

[0024] Preferably, the biomaterial usable in the context of the invention may be a biological matrix, a polymer or a mixture thereof.

[0025] Thus, monomethyl dipropylene glycol ether or one of its derivatives can be used to purify biological matrices such as acellular dermal matrices and also to purify polymers such as biopolymers, in particular P4HB.

[0026] The invention also relates to a method of purifying a biomaterial comprising at least one step of immersing said biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives.

[0027] Advantageously, the method according to the invention is simple to use, suitable for all types of biomaterials without denaturing them and is not expensive to implement.

[0028] The present invention also relates to the use of monomethyl dipropylene glycol ether or one of its derivatives to prevent infection of a human being or an animal receiving a transplant of a medical device made up of or comprising at least one biomaterial.

[0029] Advantageously, monomethyl dipropylene glycol ether or one of its derivatives prevents infections by its depyrogenating action.

[0030] Other features and advantages will become apparent from the detailed description of the invention and the purely illustrative and in no way limiting examples of the scope of the invention. Detailed description of the invention Definitions

[0031] For the purposes of this invention, "Allograft" means a biological matrix, a graft, from a donor belonging to the same biological species as the recipient.

[0032] For the purposes of the invention, "autograft" means a graft where the donor and recipient are the same person.

[0033] For the purposes of this invention, "one of its derivatives" means any chemical compound obtained by structural modification of monomethyl dipropylene glycol ether. These modifications include, but are not limited to, the substitution, addition, or removal of one or more atoms or functional groups in the basic structure. These derivatives retain the main skeleton of monomethyl dipropylene glycol ether while exhibiting structural variations that may affect their physical, chemical, or biological properties. This definition includes all isomers, tautomers, salts, esters, ethers, metal complexes, and other modified forms of monomethyl dipropylene glycol ether, as well as mixtures thereof.

[0034] For the purposes of this invention, "non-pyrogenic water" means water free from any substance of bacterial origin capable of raising the temperature of a subject to whom it is injected.

[0035] For the purposes of this invention, "undesirable elements" are understood to mean pyrogenic molecules such as endotoxins, and / or lipids, in particular bacterial lipids.

[0036] For the purposes of this invention, "endotoxin" refers to a heat-stable bacterial toxin released by the lysis or growth of Gram-negative bacteria. Endotoxins may be lipopolysaccharides, which are essential components of the cell walls of these bacteria.

[0037] For the purposes of this invention, "immersion" means placing a biomaterial in a solution comprising DPM so that it is completely covered or enveloped by that solution.

[0038] For the purposes of this invention, "biological matrix" means a biomaterial derived from the human or animal species.

[0039] For the purposes of this invention, a "pyrogenic molecule" is defined as a substance capable of causing an increase in body temperature when introduced into the body. These molecules are of paramount importance in the field of biomaterials because they can contaminate these materials during their manufacture or handling, and can thus be introduced into the body during implantation of the material.

[0040] For the purposes of this invention, "PHAs" refers to polyhydroxyalkanoates, which are biodegradable polyesters.

[0041] For the purposes of this invention, "polymer" means polymers, absorbable or not, natural or synthetic, which are biocompatible and therefore allow their use in the medical field.

[0042] For the purposes of this invention, "P4HB" refers to a specific PHA, meaning Poly-4-hydroxybutyrate. This is a homopolymer with a 4-hydroxybutyrate unit and a melting point between 60 and 65°C.

[0043] For the purposes of this invention, "solution" means a homogeneous mixture resulting from the total or partial dissolution of one or more solute(s) in a solvent.

[0044] By "purification" of a biomaterial within the meaning of the invention, we mean the reduction of the content of at least one undesirable element in the biomaterial. In particular, by purification of a biomaterial according to the invention, we mean the reduction of the content of at least one pyrogenic molecule in the biomaterial, also called depyrogenation, more preferably the reduction of the endotoxin content.

[0045] By "purifying" a biomaterial within the meaning of the invention, we mean reducing the content of at least one undesirable element in the biomaterial. In particular, by purifying a biomaterial according to the invention, we mean depyrogenating a biomaterial.

[0046] By "denaturation temperature" for the purposes of the invention, we mean the temperature at which a biomaterial undergoes an irreversible change.

[0047] For the purposes of this invention, "melting temperature" means the temperature at which a polymer changes from a solid to a liquid state.

[0048] For the purposes of this invention, "Xenograft" means a biological matrix, a graft, from a donor belonging to a biological species different from that of the recipient.

[0049] Uses of an agent to purify a biomaterial

[0050] The present invention therefore relates to the use of an agent to purify a biomaterial, said agent being monomethyl dipropylene glycol ether or one of its derivatives.

[0051] Advantageously, the inventors discovered that monomethyl dipropylene glycol ether made it possible to purify a biomaterial, in particular by removing pyrogenic molecules from said biomaterial, more particularly by reducing the endotoxin content and / or by removing lipids of exogenous origin from said biomaterial.

[0052] Monomethyl dipropylene glycol ether, CAS number 34590-94-8, has many advantages. Initially known for its use as an industrial degreaser, monomethyl dipropylene glycol ether is a neutral solvent with low toxicity.

[0053] Surprisingly, the inventors discovered that monomethyl dipropylene glycol ether or one of its derivatives made it possible to purify a biomaterial so as to make it suitable for implantation in humans or animals.

[0054] Preferably, the purification consists of reducing the content of at least one pyrogenic molecule of the biomaterial, more preferably reducing the content of endotoxins, in particular reducing the content of at least one endotoxin.

[0055] According to one embodiment, the purification of the biomaterial consists of reducing the lipid content, in particular reducing the content of at least one lipid, preferably at least one bacterial lipid.

[0056] In other words, the purification of the biomaterial consists preferentially of reducing the content of endotoxins and / or lipids, in particular bacterial lipids, of said biomaterial.

[0057] According to one embodiment, the purification of the biomaterial consists of reducing the content of at least one non-pyrogenic molecule, preferably at least one lipid, even more preferably a non-pyrogenic fatty acid.

[0058] Certain non-pyrogenic fatty acids are considered undesirable in the context of the invention. The presence of non-pyrogenic fatty acids in the biomaterial presents certain disadvantages, namely: - preventing good cell adhesion to biomaterials, making biomaterial integration more difficult; - to form a biofilm promoting the adhesion and growth of bacteria; and - to degrade the biomaterial.

[0059] Advantageously, monomethyl dipropylene glycol ether or one of its derivatives makes it possible to reduce the lipid content, preferably fatty acid content, of the biomaterial.

[0060] According to another embodiment, the purification of the biomaterial consists of reducing the content of at least one pyrogenic molecule, preferably reducing the endotoxin content, and at least one non-pyrogenic molecule, preferably a fatty acid.

[0061] The biomaterial usable in the context of the invention can be chosen from a biological matrix, a polymer and their mixture.

[0062] Advantageously, monomethyl dipropylene glycol ether or one of its derivatives is suitable for use on all types of biomaterials.

[0063] When the biomaterial includes a biological matrix, this can be a matrix of human and / or non-human animal origin (Allograft or Xenograft).

[0064] According to one embodiment, the biomaterial comprises a biological matrix of porcine, bovine, equine, caprine, fish origin or mixtures thereof.

[0065] Preferably, the biomaterial usable in the context of the invention comprises an acellular biological matrix. In a particular embodiment, the biomaterial is an acellular biological matrix. There are many known processes for obtaining an acellular biological matrix. The processes used may be enzymatic and / or based on chemical solutions and / or relying on mechanical processes. The process used must be one that yields an acellular biological matrix suitable for use in surgery, particularly for soft tissue reconstruction.

[0066] When the biomaterial comprises a polymer, the latter may be of synthetic or natural origin, also called a biopolymer. According to a particular embodiment, the biomaterial is a polymer.

[0067] The polymer usable in the context of the invention can be any type of polymer suitable for use as a biomaterial, in particular polymers obtained by bacterial fermentation. Indeed, any biomaterial comprising molecules that can be obtained by bacterial fermentation may contain pyrogenic molecules.

[0068] According to a particular embodiment, monomethyl dipropylene glycol ether or one of its derivatives can be used to purify a biomaterial, said biomaterial comprising a polymer obtained by bacterial fermentation.

[0069] Preferably, the polymer usable in the context of the invention is chosen from the following polymers: poly(glycolides), poly(lactide-co-glycolides); poly(lactic acid), poly(glycolic acid), poly(lactic acid-co-glycolic acids), polycaprolactones, poly(orthoesters), polyanhydrides, poly(phosphazenes), polyhydroxyalkanoates, polyesters, poly(lactide-co-caprolactones), polycarbonates, tyrosine polycarbonates, polyamides, polyesteramides, poly(dioxanones), poly(alkylene alkylates), polyethers, polyvinylpyrrolidones or PVP, polyurethanes, polyetheresters, polyacetals, polycyanoacrylates, poly(oxyethylene) / poly(oxypropylene) copolymers, polyacetals, polyketals, polyphosphates, polyphosphoesters, polyalkylene oxalates, polyalkylene succinates, poly(maleic acids), chitin, chitosan and mixtures thereof

[0070] According to a particularly preferred embodiment, the polymer is a polyhydroxyalkanoates selected from at least Poly-4-hydroxybutyrate, copolymers of Poly-4-hydroxybutyrate and mixtures thereof.

[0071] PHAs constitute a family of materials produced by numerous microorganisms. For example, US patent 6,316,262 of Metabolix, Inc. of Cambridge, MA, USA, describes a method for obtaining a biological system for the production of polyhydroxyalkanoate polymers containing 4-hydroxy acids. US patents 6,245,537, 6,623,748, 7,244,442, and 8,231,889 also describe methods for the production of PHAs.

[0072] According to one embodiment, the invention relates to the use of an agent to purify a biomaterial comprising or consisting of P4HB, said agent being monomethyl dipropylene glycol ether.

[0073] Advantageously, P4HB exhibits total or partial solubility in monomethyl dipropylene glycol ether or one of its derivatives, thus allowing optimized purification.

[0074] According to one embodiment, the invention relates to the use of an agent to purify a biomaterial, said agent being monomethyl dipropylene glycol ether or one of its derivatives and is used in a composition in which it represents at least 50% by weight of the total weight of said composition.

[0075] Preferably, monomethyl dipropylene glycol ether or one of its derivatives is used to purify a biomaterial and represents at least 60%, in particular at least 70%, more preferably at least 80%, even more preferably at least 90% by weight relative to the total weight of a composition.

[0076] According to a particular embodiment, the invention relates to the use of a composition consisting of monomethyl dipropylene glycol ether or one of its derivatives to purify a biomaterial.

[0077] According to one embodiment, said composition comprising monomethyl dipropylene glycol ether or one of its derivatives is in solid form, preferably in powder form, or liquid.

[0078] Preferably, said composition comprising monomethyl dipropylene glycol ether or one of its derivatives is in liquid form. Method for purifying a biomaterial

[0079] The invention also relates to a method for purifying a biomaterial comprising at least one step of immersing said biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives.

[0080] Advantageously, the purification method according to the invention is simple to use, inexpensive, and notably allows for the reduction of the content of at least one pyrogenic molecule in the biomaterial, more particularly the reduction of endotoxin levels. In addition, the purification method according to the invention also allows for the reduction of the content of at least one non-pyrogenic molecule such as lipids, preferably fatty acids.

[0081] Immersion is carried out at a temperature adapted according to the content of monomethyl dipropylene glycol ether or one of its derivatives in the solution but also according to the nature of the biomaterial used.

[0082] Preferably, the method according to the invention relates to the purification of a biomaterial chosen from a biological matrix, a polymer or their mixture.

[0083] According to one embodiment, when the biomaterial is or comprises a biological matrix, the immersion of the biological matrix is ​​carried out at a temperature lower than the denaturation temperature of said biological matrix.

[0084] By way of example, when the biomaterial is or includes a dermal biological matrix, the immersion is carried out at a temperature lower than the denaturation temperature of collagen.

[0085] According to another embodiment, when the biomaterial is or comprises a polymer, the immersion of the polymer is carried out at a temperature higher than the melting temperature of said polymer.

[0086] According to one embodiment, when the biomaterial is P4HB, the immersion is carried out at a temperature higher than the melting temperature of P4HB, thus allowing to optimize its solubilization in monomethyl dipropylene glycol ether or one of its derivatives.

[0087] According to a particular embodiment, the invention relates to a method for purifying P4HB comprising at least one step of immersing said P4HB in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives, at a temperature above 60°C, preferably between 60 and 80°C.

[0088] According to one embodiment, the immersion of said biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives is carried out for a period of at least 5 minutes, preferably at least 10 minutes, in particular at least 20 minutes, more preferably at least 30 minutes.

[0089] According to one embodiment, the method according to the invention comprises carrying out the following steps: a) immersion of a biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives; b) Recovery of the purified biomaterial from step a).

[0090] According to one embodiment, the method according to the invention comprises at least 2 immersion steps, preferably at least 3 immersion steps of said biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives.

[0091] Thus, according to one embodiment, the purification method according to the invention comprises the implementation of the following steps: a) immersion of a biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives; b) Recovery of the purified biomaterial from step a); a') immersion of a biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives; b') Recovery of the purified biomaterial from step a') a”) immersion of a biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives; b”) Recovery of the purified biomaterial from step a”).

[0092] Advantageously, the multiple immersion stages allow the content of pyrogenic molecules of the biomaterial, such as endotoxins and lipids, to be progressively reduced at each immersion.

[0093] Preferably, the solution of step a), the solution of step a') and the solution of step a”) comprise at least 50% of monomethyl dipropylene glycol ether or one of its derivatives, more preferably at least 60%, in particular at least 75%, even more preferably 90% by weight relative to the weight of the solution.

[0094] According to a particular embodiment, at least one solution chosen from the solution of step a), the solution of step a') and the solution of step a”) and their combinations is made up of monomethyl dipropylene glycol ether or one of its derivatives.

[0095] According to one embodiment, the purification method according to the invention includes at least one immersion step carried out under agitation.

[0096] As described above, the biomaterial usable in the context of the invention can be chosen from a biological matrix, a polymer or a mixture thereof.

[0097] Thus, according to one embodiment, the invention relates to a method of purifying P4HB comprising at least one step of immersing said biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives.

[0098] According to a particular embodiment, the method according to the invention comprises carrying out the following steps: a) immersion of P4HB in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives, preferably at least 50% by weight of monomethyl dipropylene glycol ether or one of its derivatives relative to the weight of the solution; b) Recovery of the purified P4HB from step a), preferably by rinsing with pyrogen-free water.

[0099] Advantageously, the addition of pyrogen-free water allows the P4HB to precipitate and thus the purified P4HB to be recovered.

[0100] According to one embodiment, recovery step b) is carried out at a temperature lower than the denaturation temperature of the biomaterial.

[0101] A person skilled in the art is able to select a technique for recovering the purified biomaterial according to the denaturation temperature of said biomaterial.

[0102] According to a particular embodiment, step b) can be carried out by rinsing with pyrogen-free water, evaporation, lyophilization and combinations thereof.

[0103] The invention also relates to a biomaterial obtained according to any one of the embodiments of the purification method according to the invention.

[0104] Preferably, the biomaterial according to the invention comprises an endotoxin content measured by the horseshoe crab amaebocyte lysate method of less than 20 IU / Unit, preferably an endotoxin content of less than 10 IU / Unit, more preferably an endotoxin content of less than 5 IU / Unit, even more preferably an endotoxin content of less than 3 IU / Unit.

[0105] According to one embodiment, the biomaterial according to the invention comprises a lipid content measured by the determination of residual fatty acids by gas chromatography coupled with mass spectrometry of less than 5000 ppm, preferably less than 1000 ppm, in particular less than 500 ppm.

[0106] According to a particular embodiment, the biomaterial according to the invention comprises an endotoxin content measured by the horseshoe crab amaebocyte lysate method of less than 20 IU / Unit and / or a lipid content measured by the assay of residual fatty acids by gas chromatography coupled to mass spectrometry of less than 5000 ppm.

[0107] Monomethyl dipropylene glycol ether to prevent infection

[0108] Finally, the invention relates to monomethyl dipropylene glycol ether or one of of its derivatives to prevent infection of a human being or an animal intended to receive a transplant of a medical device made up of or comprising at least one biomaterial.

[0109] By virtue of its action on pyrogenic molecules and exogenous lipids, monomethyl dipropylene glycol ether or one of its derivatives exhibits a prophylactic effect, particularly on biomaterials such as biological matrices and polymers.

[0110] Thus, monomethyl dipropylene glycol ether or one of its derivatives is capable of reducing the risks of infection during the use and / or implantation of a biomaterial in humans or animals.

[0111] Monomethyl dipropylene glycol ether or one of its derivatives is thus a versatile prophylactic agent, allowing the treatment of all types of biomaterial, and at a lower cost. Examples

[0112] Example 1: Purification of the P4HB biopolymer

[0113] The P4HB used in this example is produced by fermentation using the E. coli bacterium as a vector.

[0114] In order to recover the biopolymer accumulated at the end of the cycle in the bacterium, the latter is destroyed. In doing so, it releases a very large quantity of endotoxins but also of bacterial lipids, also called bacterial fatty acids (FA).

[0115] Preliminary thermal analyses have established the thermal properties of the treated P4HB: glass transition (Tv) = -52°C; melting point Tm = 57°C; and Denaturation temperature = 394°C.

[0116] For the implementation of the P4HB purification method, a solution comprising at least 50% of DPM was used.

[0117] Since the flash point of the solution used is 82°C, a treatment temperature of 70°C was chosen, a temperature compatible with P4HB. Thus, all the immersions described below are carried out at 70°C.

[0118] P4HB was treated by implementing the following steps: a) Immersion of P4HB in a solution comprising at least 50% monomethyl dipropylene glycol ether for a period of 30 minutes under stirring; b) Recovery of the purified P4HB from step a) by adding pyrogen-free water; a') immersion of P4HB in a solution comprising at least 50% monomethyl dipropylene glycol ether for a period of 30 minutes under stirring; b') Recovery of the purified P4HB from step a') by adding pyrogen-free water a”) immersion of P4HB in a solution comprising at least 50% monomethyl dipropylene glycol ether for a period of 30 minutes under stirring; b”) Recovery of the purified P4HB from step a”) by adding pyrogen-free water.

[0119] In the context of Example 1, solutions A, B and C have an identical content of monomethyl dipropylene glycol ether.

[0120] The P4HB is thus recovered, the solvent / water phase is eliminated.

[0121] The results are reported in Table 1 below. [Tables 1] Before immersion After 1 immersion (step b) After 2 immersions (step b') After 3 immersions (step b”) Endotoxin assay 598 491 IU / Unit 7.5 IU / Unit 4.8 IU / Unit 2.7 IU / Unit Lipid assay 7000 PPM 5000 PPM 1000 PPM 400 PPM

[0122] For the preparation of Table 1, the assay of endotoxins was carried out by the Limule Amebocyte Lysate method.

[0123] In addition, the lipid content was determined by measuring residual fatty acids using gas chromatography coupled with mass spectrometry.

[0124] The results obtained in this example show that monomethyl dipropylene glycol ether can be used to purify a biomaterial such as P4HB.

[0125] Example 2: Purification of a biological matrix

[0126] For the realization of this example, the biological matrix is ​​an acellular dermal matrix (ADM).

[0127] In order for this matrix to comply with current regulations, it is necessary that the endotoxin content be less than 20 IU.

[0128] ADMs are heat-sensitive matrices composed mainly of collagen. It is therefore essential to avoid temperatures above 40°C to prevent their denaturation.

[0129] The solution used in the purification method according to the invention in this example consists of 100% monomethyl dipropylene glycol ether.

[0130] The acellular dermal matrix, of porcine origin, was treated by immersion in said solution consisting of monomethyl dipropylene glycol ether at 30°C for a period of 60 min. The matrix was then rinsed with pyrogen-free water and then lyophilized.

[0131] The results are shown in Table 2 below: [Tables 2] Before immersion After 1 immersion Endotoxin dosage* 73 IU / Unit 4 IU / Unit

[0132] For the preparation of Table 2, the assay of endotoxins was carried out by the Limule Amebocyte Lysate method.

[0133] The results obtained in this example show that monomethyl dipropylene glycol ether can be used to purify a biomaterial such as a biological matrix.

Claims

Demands

1. Use of an agent to purify a biomaterial, characterized in that the agent is monomethyl dipropylene glycol ether or one of its derivatives.

2. Use according to the preceding claim, to reduce the content of at least one pyrogenic molecule and / or lipids in the biomaterial.

3. Use according to the preceding claim, characterized in that at least one pyrogenic molecule is an endotoxin.

4. Use according to any one of the preceding claims, characterized in that said agent is used in a composition and in that it constitutes at least 50% by weight of the total weight of said composition.

5. Use according to any one of the preceding claims, characterized in that the biomaterial is a biological matrix, a polymer and their mixture.

6. Use according to the preceding claim, characterized in that the biomaterial is a polymer selected from poly(glycolides), poly(lactide-co-glycolides); poly(lactic acid), poly(glycolic acid), poly(lactic acid-co-glycolic acids), polycaprolactones, poly(orthoesters), polyanhydrides, poly(phosphazenes), polyhydroxyalkanoates, polyesters, poly(lactide-co-caprolactones), polycarbonates, tyrosine polycarbonates, polyamides, polyesteramides, poly(dioxanones), poly(alkylene alkylates), polyethers, polyvinylpyrrolidones or PVP, polyurethanes, polyetheresters, polyacetals, polycyanoacrylates, poly(oxyethylene) / poly(oxypropylene) copolymers, polyacetals, polyketals, polyphosphates, polyphosphoesters, polyalkylene oxalates, polyalkylene succinates, poly(maleic acids), chitin, chitosan and mixtures thereof

7. Use according to the preceding claim, characterized in that the biomaterial is selected from Poly-4-hydroxybutyrate, a copolymer of Poly-4-hydroxybutyrate and mixtures thereof.

8. Monomethyl dipropylene glycol ether or one of its derivatives for use in preventing infection in a human being or an animal intended to receive a transplant of a medical device made up of or comprising at least one biomaterial.

9. Method of purifying a biomaterial comprising at least one step of immersing said biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives.

10. A method according to any one of the preceding claims, characterized in that it comprises carrying out the following steps: a) immersion of a biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives; b) recovery of the purified biomaterial from step a).

11. Method according to any one of claims 9 or 10, characterized in that the biomaterial is chosen from a biological matrix, a polymer and their mixture.

12. Method according to the preceding claim, characterized in that the biomaterial is or comprises a biological matrix and in that the immersion of the biological matrix is ​​carried out at a temperature lower than the denaturation temperature of said biological matrix.

13. Method according to claim 11, characterized in that the biomaterial is or comprises a polymer and in that the immersion of the polymer is carried out at a temperature above the melting temperature of said polymer.

14. Method according to any one of claims 9 to 13, characterized in that the biomaterial immersion step is carried out for a period of at least 5 minutes.

15. A method according to any one of claims 9 to 14, characterized in that the solution in which the biomaterial is immersed comprises at least 50% by weight of monomethyl dipropylene glycol ether or one of its derivatives relative to the weight of the step solution

16. dj. Method according to any one of claims 9 to 15, characterized in that recovery step b) is carried out by rinsing with pyrogen-free water, evaporation or freeze-drying or combinations thereof.

17. Biomaterial obtained by a purification method according to any one of claims 9 to 16, characterized in that it has: - an endotoxin content measured by the horseshoe crab amaebocyte lysate method of less than 20 IU / Unit, and / or - a lipid content measured by the determination of residual fatty acids by gas chromatography coupled with mass spectrometry of less than 5000ppm.