Use of dipropylene glycol monomethyl ether for purifying a biomaterial

Abstract

The present invention relates to the use of a specific agent, dipropylene glycol monomethyl ether, for purifying a biomaterial, a purification method using dipropylene glycol monomethyl ether, and a biomaterial obtained from said purification method.

Description

[0001] USE OF DIPROPYLENE GLYCOL MONOMETHYL ETHER TO PURIFY A BIOMATERIAL

[0002] technical field

[0003] 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.

[0004] State of the art

[0005] Biomaterials are synthetic or living materials designed to be implanted into a living organism to replace part or function of an organ or tissue.

[0006] Used in many therapeutic areas, biomaterials offer many advantages but also many challenges, particularly in terms of the risk of adverse reactions or complications.

[0007] To avoid these risks, legislators have implemented strict regulations, including controls on the composition of biomaterials. More specifically, these regulations aim to control the purity of biomaterials to ensure their biocompatibility and effectiveness.

[0008] Therefore, 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.

[0009] Purity control is a critical step in the production of biomaterials. To standardize the quality of biomaterials, regulations define tolerance thresholds that must be met, particularly with regard to the control of pyrogenic molecules.

[0010] 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.

[0011] Endotoxins are toxins located in the outer membrane of certain Gram-negative bacteria. These toxins primarily consist of proteins, phospholipids, and lipopolysaccharides (LPS). Widely present in nature, heat-stable, and small enough to pass through conventional sterilization filters, endotoxins are particularly difficult to eliminate. 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 ensure their safe use in humans and animals.

[0012] 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.

[0013] To meet regulatory standards, manufacturers develop and research purification processes. However, these processes are not suitable for the depyrogenation of biomaterials, that is, the reduction of the pyrogenic molecule content.

[0014] For example, sterilization processes aim to inactivate microorganisms on or in biomaterials, but do not target pyrogenic molecules, particularly endotoxins. Therefore, they are not suitable for reducing the pyrogenic content of biomaterials.

[0015] Other processes described in the prior art make it possible to avoid contamination by pyrogenic molecules, in particular by endotoxins such as: a) techniques for manufacturing biomaterials that prevent or control contamination by endotoxins, by avoiding, for example, the use of gram-negative bacteria; b) techniques for depyrogenation by inactivation of endotoxins, in particular via the use of heat treatments or the use of ozone; or c) techniques for the physical removal of endotoxins, in particular using rinsing, distillation or ultrafiltration steps.

[0016] The application of so-called "clean" biomaterial manufacturing techniques does not guarantee the elimination of pyrogenic molecules. While these methods are suitable for drug production, their implementation can be more complex and often more expensive for medical devices, particularly biomaterials, due to the specific nature of these devices.

[0017] Current deryogenic 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 byproducts, has variable effectiveness, and is too costly to implement.

[0018] Physical removal methods, on the other hand, are not very effective and cannot always replace depyrogenation. Thus, the methods described in the prior art for removing or inactivating pyrogenic elements and / or lipids of exogenous origin are unsuitable, too complex, and often expensive to implement.

[0019] There is therefore a need for an alternative solution to purify a biomaterial in order to reduce the content of endotoxins and lipids, particularly bacterial lipids, suitable for all types of biomaterials, including biological matrices and polymers.

[0020] Summary of the invention

[0021] 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.

[0022] 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.

[0023] Monomethyl dipropylene glycol ether is not subject to REACH classification (European regulation no. 1907 / 2006) and has low toxicity.

[0024] Advantageously, monomethyl dipropylene glycol ether or one of its derivatives can be used to purify biomaterials, preferably by reducing the content of at least one pyrogenic molecule in the biomaterial.

[0025] The inventors discovered, surprisingly, that monomethyl dipropylene glycol ether or one of its derivatives was capable of purifying all types of biomaterials.

[0026] Preferably, the biomaterial usable in the context of the invention can be a biological matrix, a polymer or a mixture thereof.

[0027] 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, including P4HB.

[0028] 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.

[0029] 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.

[0030] The present invention also relates to the use of monomethyl dipropylene glycol ether or one of its derivatives to prevent infection in a human or animal receiving a transplant of a medical device made of or comprising at least one biomaterial. Advantageously, monomethyl dipropylene glycol ether or one of its derivatives prevents infections through its depyrogenating action.

[0031] Other features and advantages will become apparent from the detailed description of the invention and the examples which are purely illustrative and in no way limiting of the scope of the invention.

[0032] Detailed description of the invention

[0033] Definitions

[0034] For the purposes of this invention, "Allograft" means a biological matrix, a graft, originating from a donor belonging to the same biological species as the recipient.

[0035] For the purposes of this invention, "autograft" means a transplant where the donor and recipient are the same person.

[0036] 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.

[0037] 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.

[0038] For the purposes of this invention, "undesirable elements" are understood to mean pyrogenic molecules such as endotoxins, and / or lipids, in particular bacterial lipids.

[0039] 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.

[0040] 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.

[0041] For the purposes of this invention, "biological matrix" means a biomaterial derived from the human or animal species.

[0042] 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.

[0043] For the purposes of this invention, "PHAs" refers to polyhydroxyalkanoates, which are biodegradable polyesters.

[0044] 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.

[0045] For the purposes of this invention, "P4HB" refers to a specific PHA, meaning Poly-4-hydroxybutyrate. It is a homopolymer with a 4-hydroxybutyrate unit and a melting point between 60 and 65°C.

[0046] 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.

[0047] For the purposes of this invention, "purification" of a biomaterial means reducing the content of at least one undesirable element in the biomaterial. In particular, purification of a biomaterial according to this invention means reducing the content of at least one pyrogenic molecule in the biomaterial, also called depyrogenation, and more preferably reducing the endotoxin content.

[0048] For the purposes of this invention, "purifying" a biomaterial means reducing the content of at least one undesirable element in the biomaterial. In particular, purifying a biomaterial according to this invention means depyrogenating it.

[0049] For the purposes of this invention, "temperature of denaturation" means the temperature at which a biomaterial undergoes an irreversible change.

[0050] For the purposes of this invention, "melting temperature" means the temperature at which a polymer changes from a solid to a liquid state.

[0051] For the purposes of this invention, "Xenograft" means a biological matrix, a graft, originating from a donor belonging to a biological species different from that of the recipient.

[0052] Uses of an agent to purify a biomaterial

[0053] 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.

[0054] Advantageously, the inventors discovered that monomethyl dipropylene glycol ether can purify a biomaterial, notably by removing pyrogenic molecules from said biomaterial, more specifically by reducing the endotoxin content and / or removing lipids of exogenous origin from said biomaterial. Monomethyl dipropylene glycol ether, CAS number 34590-94-8, offers numerous advantages. Initially known for its use as an industrial degreaser, monomethyl dipropylene glycol ether is a neutral solvent with low toxicity.

[0055] Surprisingly, the inventors discovered that monomethyl dipropylene glycol ether or one of its derivatives could purify a biomaterial to make it suitable for implantation in humans or animals.

[0056] Preferably, 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.

[0057] 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.

[0058] In other words, the purification of the biomaterial consists preferentially of reducing the content of endotoxins and / or lipids, particularly bacterial lipids, of said biomaterial.

[0059] 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.

[0060] 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:

[0061] - preventing good cell adhesion to biomaterials, making biomaterial integration more difficult;

[0062] - to form a biofilm that promotes bacterial adhesion and growth; and

[0063] - degrade the biomaterial.

[0064] Advantageously, monomethyl dipropylene glycol ether or one of its derivatives makes it possible to reduce the lipid content, preferentially fatty acid content, of the biomaterial.

[0065] 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.

[0066] The biomaterial usable in the context of the invention can be chosen from a biological matrix, a polymer and their mixture.

[0067] Advantageously, monomethyl dipropylene glycol ether or one of its derivatives is suitable for use on all types of biomaterials. When the biomaterial includes a biological matrix, this matrix can be of human and / or non-human animal origin (Allograft or Xenograft).

[0068] According to one embodiment, the biomaterial comprises a biological matrix of porcine, bovine, equine, caprine, fish origin or mixtures thereof.

[0069] Preferably, the biomaterial usable in the context of the invention comprises an acellular biological matrix. In one particular embodiment, the biomaterial is an acellular biological matrix. Numerous known processes exist for obtaining an acellular biological matrix. These processes may be enzymatic and / or based on chemical solutions and / or rely 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.

[0070] According to a preferred embodiment of the invention, the biomaterial is temperature-sensitive. This thermal sensitivity can manifest itself through structural, mechanical, or functional changes in the biomaterial when exposed to temperature variations. For example, the biomaterial may exhibit a relatively low denaturation or phase transition temperature, typically below 60°C, preferably below 50°C. This characteristic makes the biomaterial particularly difficult to purify using conventional methods involving high temperatures.

[0071] The use of monomethyl dipropylene glycol ether or one of its derivatives according to the invention offers the particular advantage of enabling the efficient purification of these heat-sensitive biomaterials without compromising their structural or functional integrity. Indeed, the purification agent according to the invention can be used at temperatures compatible with the thermal stability of the biomaterial, while ensuring the effective removal of pyrogenic molecules and / or undesirable lipids.

[0072] In another advantageous aspect of the invention, the biomaterial is intended for subcutaneous use. Unlike prior art devices such as contact lenses or orthodontic appliances, which are used on the surface or in the oral cavity, the biomaterials according to the invention are designed to be implanted under the skin. This subcutaneous use imposes particularly stringent requirements in terms of the purity and biocompatibility of the biomaterial.

[0073] When a biomaterial includes a polymer, this polymer can be of synthetic or natural origin, also called a biopolymer. In a particular embodiment, the biomaterial is a polymer.

[0074] 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. 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.

[0075] 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

[0076] 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.

[0077] Polyhydroxyalkanoate (PHA) polymers are a family of materials produced by numerous microorganisms. For example, US patent 6,316,262, held by Metabolix, Inc. of Cambridge, MA, USA, describes a method for obtaining a biological system for producing 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 synthesizing PHAs.

[0078] 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.

[0079] Advantageously, P4HB exhibits total or partial solubility in monomethyl dipropylene glycol ether or one of its derivatives, thus enabling optimized purification.

[0080] 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.

[0081] Preferably, monomethyl dipropylene glycol ether or one of its derivatives is used to purify a biomaterial and constitutes at least 60%, in particular at least 70%, more preferably at least 80%, and even more preferably at least 90% by weight relative to the total weight of the composition. 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.

[0082] 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.

[0083] Preferably, said composition comprising monomethyl dipropylene glycol ether or one of its derivatives is in liquid form.

[0084] Method for purifying a biomaterial

[0085] 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.

[0086] 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.

[0087] 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.

[0088] Preferably, the method according to the invention relates to the purification of a biomaterial chosen from a biological matrix, a polymer or a mixture thereof.

[0089] 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.

[0090] For example, when the biomaterial is or includes a dermal biological matrix, immersion is carried out at a temperature lower than the denaturation temperature of collagen.

[0091] According to another embodiment, when the biomaterial is or comprises a polymer, the immersion of the polymer is carried out at a temperature above the melting temperature of said polymer.

[0092] In one embodiment, when the biomaterial is P4HB, the immersion is carried out at a temperature above the melting point of P4HB, thereby optimizing its solubilization in monomethyl dipropylene glycol ether or one of its derivatives. In 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.

[0093] 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.

[0094] 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).

[0095] 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.

[0096] Thus, according to one embodiment, the purification method according to the invention comprises carrying out the following steps: a) immersing a biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives; b) recovering the purified biomaterial from step a); a') immersing a biomaterial in a solution comprising monomethyl dipropylene glycol ether or one of its derivatives; b') recovering the purified biomaterial from step a'). 1 ') 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'').

[0097] Advantageously, the multiple immersion stages allow the pyrogenic molecule content of the biomaterial, such as endotoxins and lipids, to be progressively reduced with each immersion.

[0098] Preferably, the solution of step a), the solution of step a'), and the solution of step a'') comprise at least 50% monomethyl dipropylene glycol ether or one of its derivatives, more preferably at least 60%, in particular at least 75%, and even more preferably 90% by weight relative to the weight of the solution. According to a particular embodiment, at least one solution selected from the solution of step a), the solution of step a'), and the solution of step a'') and combinations thereof, consists of monomethyl dipropylene glycol ether or one of its derivatives.

[0099] According to one embodiment, the purification method according to the invention includes at least one immersion step carried out under agitation.

[0100] As described previously, the biomaterial usable in the context of the invention can be chosen from a biological matrix, a polymer or a mixture thereof.

[0101] 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.

[0102] According to a particular embodiment, the method according to the invention comprises carrying out the following steps: a) immersing 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) recovering the purified P4HB from step a), preferably by rinsing with pyrogen-free water.

[0103] Advantageously, the addition of pyrogen-free water allows the P4HB to precipitate and thus the purified P4HB to be recovered.

[0104] According to one embodiment, recovery step b) is carried out at a temperature lower than the denaturation temperature of the biomaterial.

[0105] A person skilled in the art is able to select a technique for recovering the purified biomaterial based on the denaturation temperature of said biomaterial.

[0106] According to a particular embodiment, step b) can be carried out by rinsing with pyrogen-free water, evaporation, freeze-drying and combinations thereof.

[0107] The invention also relates to a biomaterial obtained according to any one of the embodiments of the purification method according to the invention.

[0108] 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, and even more preferably an endotoxin content of less than 3 IU / unit. In one embodiment, the biomaterial according to the invention comprises a lipid content, measured by gas chromatography-mass spectrometry, of less than 5000 ppm, preferably less than 1000 ppm, and in particular less than 500 ppm.

[0109] 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.

[0110] The purification method according to the invention, using monomethyl dipropylene glycol ether or one of its derivatives, makes it possible to achieve the purity levels required for these subcutaneous applications by effectively removing pyrogenic molecules and lipids that could cause inflammatory reactions or rejection during implantation. Furthermore, the method according to the invention makes it possible to obtain this high purity without resorting to aggressive conditions that could alter the properties of the biomaterial.

[0111] Monomethyl dipropylene glycol ether to prevent infection

[0112] Finally, the invention relates to monomethyl dipropylene glycol ether or one of its derivatives for 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.

[0113] Due to its action on pyrogenic molecules and exogenous lipids, monomethyl dipropylene glycol ether or one of its derivatives has a prophylactic effect, particularly on biomaterials such as biological matrices and polymers.

[0114] 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.

[0115] Monomethyl dipropylene glycol ether or one of its derivatives is thus a versatile prophylactic agent, allowing the treatment of all types of biomaterials, and at a lower cost. P4HB

[0116] The P4HB used in this example is produced by fermentation using the E. coli bacterium as a vector.

[0117] To recover the biopolymer accumulated at the end of the cycle in the bacterium, the bacterium is destroyed. In doing so, it releases a very large quantity of endotoxins as well as bacterial lipids, also known as bacterial fatty acids (FAs). Preliminary thermal analyses have established the thermal properties of the treated P4HB:

[0118] *glass transition (Tv) = -52°C;

[0119] *melting point Tm = 57°C; and

[0120] *Denaturation temperature = 394°C.

[0121] For the implementation of the P4HB purification method, a solution containing at least 50% DPM was used.

[0122] Since the flash point of the solution used is 82°C, a processing temperature of 70°C was chosen, a temperature compatible with P4HB. Therefore, all the immersions described below are carried out at 70°C.

[0123] P4HB was treated by implementing the following steps: a) immersion of P4HB in a solution containing at least 50% monomethyl dipropylene glycol ether for 30 minutes with stirring; b) recovery of the purified P4HB from step a) by adding pyrogen-free water; a') immersion of P4HB in a solution containing at least 50% monomethyl dipropylene glycol ether for 30 minutes with stirring; b') recovery of the purified P4HB from step a') by adding pyrogen-free water. 1') 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 addition of pyrogen-free water.

[0124] In the context of example 1, solutions A, B and C have an identical content of monomethyl dipropylene glycol ether.

[0125] The P4HB is thus recovered, and the solvent / water phase is eliminated.

[0126] The results are shown in Table 1 below.

[0127] [Table 1] For the preparation of Table 1, the endotoxin assay was performed using the Limule Amebocyte Lysate method.

[0128] In addition, lipid analysis was carried out by measuring residual fatty acids using gas chromatography coupled with mass spectrometry.

[0129] The results obtained in this example show that monomethyl dipropylene glycol ether can be used to purify a biomaterial such as P4HB.

[0130] Example 2: Purification of a biological matrix

[0131] For the realization of this example, the biological matrix is ​​an acellular dermal matrix (ADM).

[0132] For this matrix to comply with current regulations, it is necessary that the endotoxin content be less than 20 IU.

[0133] ADMs are heat-sensitive matrices composed primarily of collagen. It is therefore essential to avoid temperatures above 40°C to prevent their denaturation.

[0134] The solution used in the purification method according to the invention in this example consists of 100% monomethyl dipropylene glycol ether.

[0135] The acellular dermal matrix, of porcine origin, was treated by immersion in the aforementioned 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 subsequently lyophilized.

[0136] The results are shown in Table 2 below:

[0137] [Table 2]

[0138] For the preparation of Table 2, the endotoxin assay was performed using the Limule Amebocyte Lysate method.

[0139] 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. 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 solution of step a).

16. 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 exhibits: - 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.

Images