Patent Description:
In cancer patients, cancer treatment affects the mucous membrane of the mouth and, stomatitis occurs easily. For example, in anti-cancer drug treatment, in radiation therapy for head and neck cancer (cancer in the range from the head to the neck) in a case where a drug that easily causes stomatitis is administered, when radiation is directly applied to the mucous membrane of the mouth, stomatitis is inevitable. The pain of stomatitis is so strong that it is difficult to eat a meal by mouth.

As a symptomatic treatment for stomatitis, a patch (for example, Aphthaseal(R) <NUM>µg, manufactured by Taisho Pharmaceutical Co. , active ingredient: triamcinolone acetonide) that is directly attached to the affected part, an ointment (for example, Dexaltin oral ointment for oral cavity, manufactured by Nippon Kayaku Co. , active ingredient: dexamethasone) that is applied to the affected part, and a spray agent (for example, Salcoat(R) capsule for oral spray 50µg, TEIJIN PHARMA LIMITED, active ingredient: beclomethasone propionate ester) that is sprayed on the affected part are mentioned.

When eating a meal by mouth, the patch attached to the affected part may be peeled off, or the ointment or the spray agent applied to the affected part may be lost, and thus the pain of stomatitis cannot be suppressed.

Accordingly, a biomaterial capable of suppressing such pain of stomatitis has been desired.

Particularly, for example, <CIT> discloses a cosmetological composition for use for the aged and/or stressed skin, and in such a cosmetological composition in which water and at least one substance forming a lamellar structure together with the water are present in the above composition, the followings are further contained;.

Further, <CIT> discloses a composition containing;.

<CIT> discloses topical bioadhesive formulations comprising low viscosity, non-liquid crystalline, mixtures of: a) at least one neutral diacyl lipid and/or at least one tocopherol; b) at least on phospholipid; c) at least one biocompatible, oxygen containing, low viscosity organic solvent; wherein at least one bioactive agent is dissolved or dispersed in the low viscosity mixture and wherein the pre-formulation forms, or is capable of forming, at least one liquid crystalline phase structure upon contact with an aqueous fluid.

However, in the cosmetological composition disclosed in <CIT> and the composition disclosed in <CIT>, the scratch resistance (the residuality on the mucous membrane when friction is applied) and the retention (attachability to the mucous membrane in a moist environment) in a case of being brought into contact with water were not at a satisfactory level as shown by Comparative Examples described later, and there was room for improvement in these compositions.

An object of the present invention is to provide a biomaterial that is excellent in scratch resistance and retention in a case of being brought into contact with water.

As a result of diligent studies to solve the above problems, the inventors of the present invention have found that the above problems can be solved by using a biomaterial including predetermined components and have completed the present invention.

That is, subject-matter of the present invention is a biomaterial as claimed in independent claim <NUM>.

According to the present invention, it is possible to provide a biomaterial that is excellent in scratch resistance and retention in a case of being brought into contact with water.

In the present specification, the range indicated by using "to" means a range including both ends before and after "to". For example, a range indicated by "A to B" includes A and B.

In addition, in the present specification, the solid content is intended to be a component contained in the composition excluding the dispersion medium component, and a component is calculated as a solid content even in a case where the property thereof is liquid.

A biomaterial according to the embodiment of the present invention includes a neutral acyl lipid, at least one selected from the group consisting of a phospholipid and a quaternary ammonium salt, and a carboxyvinyl polymer.

Hereinafter, each component of the biomaterial according to the embodiment of the present invention will be described.

The neutral acyl lipid means an electrically neutral acyl lipid. That is, the neutral acyl lipid does not include a cation moiety and an anion moiety. An acyl lipid means a lipid containing an acyl group.

Examples of the neutral acyl lipid include a neutral monoacyl lipid, a neutral diacyl lipid, and a neutral triacyl lipid.

In the biomaterial according to the embodiment of the present invention, the neutral acyl lipid contains both of a neutral monoacyl lipid and a neutral diacyl lipid, and a total content of the neutral monoacyl lipid and the neutral diacyl lipid is <NUM>% by mass to <NUM>% by mass, preferably <NUM>% by mass to <NUM>% by mass, and more preferably <NUM>% by mass, with respect to the total mass of the neutral acyl lipid.

A content of the neutral monoacyl lipid is preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the neutral acyl lipid.

A content of the neutral diacyl lipid is preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the neutral acyl lipid.

A content of the neutral triacyl lipid is preferably <NUM>% by mass to <NUM>% by mass with respect to the total mass of the neutral acyl lipid, and it is more preferable that the neutral triacyl lipid is not contained (<NUM>% by mass).

Among them, it is more preferable that a content of the neutral monoacyl lipid is <NUM>% by mass to <NUM>% by mass, a content of the neutral diacyl lipid is <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the neutral acyl lipid, and the neutral triacyl lipid is not contained.

The number of carbon atoms of the acyl group of the neutral acyl lipid is not particularly limited; however, the acyl group preferably has <NUM> to <NUM> carbon atoms and more preferably <NUM> to <NUM> carbon atoms.

The hydrocarbon group as the acyl group, excluding a carbonyl group, is preferably a saturated or unsaturated chain-type hydrocarbon group having <NUM> to <NUM> carbon atoms, and more preferably a saturated or unsaturated chain-type hydrocarbon group having <NUM> to <NUM> carbon atoms. Specific examples thereof include CH<NUM>(CH<NUM>)<NUM>-, CH<NUM>(CH<NUM>)<NUM>CH=CH(CH<NUM>)<NUM>-, and CH<NUM>(CH<NUM>)<NUM>(CH=CHCH<NUM>)<NUM>(CH<NUM>)<NUM>-; however, the examples are not limited thereto.

In a case where a neutral acyl lipid has two or more acyl groups in one molecule, the types of acyl groups may be the same or different from each other.

Examples of the neutral acyl lipid include glycerol, diglycerol, sugar (for example, inositol), and a lipid obtained by forming an ester bond between a polyol such as succinic acid and a fatty acid. Among them, an acyl glycerol is preferable and a glyceryl oleate is more preferable.

Examples of the acyl glycerol include monoacyl glycerol, diacyl glycerol, and triacyl glycerol.

In addition, examples of the glyceryl oleate include glyceryl monooleate, glyceryl the total mass of the neutral acyl lipid.

Among them, the neutral acyl lipid preferably includes both a neutral monoacyl lipid and a neutral diacyl lipid.

A content of the neutral monoacyl lipid is not particularly limited; however, it is preferably <NUM>% by mass to <NUM>% by mass, more preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the neutral acyl lipid.

A content of the neutral diacyl lipid is not particularly limited; however, it is preferably <NUM>% by mass to <NUM>% by mass, more preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the neutral acyl lipid.

A content of the neutral triacyl lipid is not particularly limited; however it is preferably <NUM>% by mass to <NUM>% by mass with respect to the total mass of the neutral acyl lipid, and it is more preferable that the neutral triacyl lipid is not contained (<NUM>% by mass).

In addition, examples of the glyceryl oleate include glyceryl monooleate, glyceryl dioleate, and glyceryl trioleate.

Here, the monoacyl glycerol and the glyceryl monooleate correspond to one aspect of the neutral monoacyl lipid described above, and the diacyl glycerol and the glyceryl dioleate correspond to one aspect of the neutral diacyl lipid described above, and the triacyl glycerol and the glyceryl trioleate correspond to one aspect of the neutral triacyl lipid.

In the present specification, the content proportions of the neutral monoacyl lipid, the neutral diacyl lipid, and the neutral triacyl lipid in the neutral acyl lipid are obtained from measurement with a high performance liquid chromatography (HPLC) method.

A content of the neutral acyl lipid in the biomaterial according to the embodiment of the present invention is not particularly limited; however, it is preferably <NUM>% by mass to <NUM>% by mass, more preferably <NUM>% by mass to <NUM>% by mass, and still more preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the solid content of the biomaterial according to the embodiment of the present invention.

The phospholipid is not particularly limited as long as it has a phosphate ester structure in the molecular structure thereof; however, a glycerophospholipid having glycerin as a skeleton and a sphingophospholipid having sphingosine as a skeleton are typical.

In both a case of the phospholipid being a glycerophosphoric acid and a case of the phospholipid being a sphingophospholipid, an acyl group derived from a fatty acid is contained in the molecule.

The number of carbon atoms of the acyl group of the phospholipid is not particularly limited; however, the acyl group preferably has <NUM> to <NUM> carbon atoms and more preferably <NUM> to <NUM> carbon atoms.

The hydrocarbon group as the acyl group, excluding a carbonyl group, is preferably a saturated or unsaturated chain-type hydrocarbon group having <NUM> to <NUM> carbon atoms, and more preferably a saturated or unsaturated chain-type hydrocarbon group having <NUM> to <NUM> carbon atoms. Specific examples of the hydrocarbon group include CH<NUM>(CH<NUM>)<NUM>-, CH<NUM>(CH<NUM>)<NUM>CH=CH(CH<NUM>)<NUM>-, and CH<NUM>(CH<NUM>)<NUM>(CH=CHCH<NUM>)<NUM>(CH<NUM>)<NUM>-; however, the examples are not limited thereto.

In a case where a phospholipid has two or more acyl groups in one molecule, the types of acyl groups may be the same or different from each other.

Specific examples of the phospholipid include phosphatidylcholine. The acyl group of the phosphatidylcholine is preferably an acyl group derived from palmitic acid (CH<NUM>(CH<NUM>)<NUM>COOH), oleic acid (CH<NUM>(CH<NUM>)<NUM>CH=CH(CH<NUM>)<NUM>COOH), or linoleic acid (CH<NUM>(CH<NUM>)<NUM>(CH=CHCH<NUM>)<NUM>(CH<NUM>)<NUM>COOH). Specific examples of the phosphatidylcholine include a PO phosphatidylcholine (a phosphatidylcholine having palmitic acid at the first position (α position), oleic acid at the second position (β position), and choline at the third position (γ position)), a DL phosphatidylcholine (a phosphatidylcholine having linoleic acid at the first position (α-position), linoleic acid at the second position (β-position), and choline at the third position (γ-position)), and a dipalmitoylphosphatidylcholine.

A content of the phospholipid in the biomaterial according to the embodiment of the present invention is not particularly limited; however, the content thereof in total together with a quaternary ammonium salt described later is preferably <NUM>% by mass to <NUM>% by mass, more preferably <NUM>% by mass to <NUM>% by mass, and still more preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the solid content of the biomaterial according to the embodiment of the present invention.

The quaternary ammonium salt is an ionic compound consisting of a quaternary ammonium cation and an anion.

The quaternary ammonium cation is preferably a polyatomic ion having a positive charge represented by the molecular formula NR<NUM>+. Here, R's each independently represent an alkyl group or an aryl group, which may have a substituent, and a plurality of R's may be the same or different from each other.

Among them, the quaternary ammonium cation of the quaternary ammonium salt is preferably a quaternary ammonium cation represented by the following formula.

In the formula, R<NUM>, R<NUM>, R<NUM>, and R<NUM> are each independently an alkyl group having <NUM> to <NUM> carbon atoms, and a hydrogen atom of the alkyl group may be substituted with an alkoxy group, an acyl group, or an acyloxy group.

The number of carbon atoms of the alkoxy group, the acyl group, or the acyloxy group, with which the hydrogen atom of the alkyl group is substituted, is not particularly limited; however, it is preferably <NUM> to <NUM>.

Examples of the quaternary ammonium salt include dioleoyloxytrimethylammonium propane chloride (DOTAP, N-[<NUM>-(<NUM>,<NUM>-dioreoiloxy)propyl]-N,N,N-trimethylammonium chloride), dioctadecenyltrimethylammonium propane chloride (DOTMA, N-[<NUM>-(<NUM>,<NUM>-dioreyloxy)propyl)]-N,N,N-trimethylammonium chloride), didecyldimethylammonium chloride, didecyldimethylammonium bromide, dilauryldimethylammonium chloride, disetyldimethylammonium chloride, disetyldimethylammonium bromide, distearyldimethylammonium chloride, distearyldimethylammonium bromide, dioleyldimethylammonium chloride, dibehenyldimethylammonium chloride, dibehenyldimethylammonium bromide, dipalmitoylethyl hydroxyethylmonium metosulfate, and distearoylethyl hydroxyethylmonium metosulfate. In addition, these quaternary ammonium salts can be used as a mixture of two or more kinds thereof.

A content of the quaternary ammonium salt in the biomaterial according to the embodiment of the present invention is not particularly limited; however, the content thereof in total togther with the phospholipid described above is preferably <NUM>% by mass to <NUM>% by mass, more preferably <NUM>% by mass to <NUM>% by mass, and still more preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the solid content of the biomaterial according to the embodiment of the present invention.

In a case of being brought into contact with water, in the biomaterial according to the embodiment of the present invention, a liquid crystal phase is formed by water, a neutral acyl lipid, a phospholipid, and/or a quaternary ammonium salt.

The carboxyvinyl polymer swells when coming into contact with water, and a network of liquid crystal micelles and a network of carboxyvinyl polymers are superpositioned. In this manner, the existence of two networks of the network of liquid crystal micelles and the network of carboxyvinyl polymers can improve scratch resistance and retention in a case where the biomaterial according to the embodiment of the present invention is brought into contact with water.

The carboxyvinyl polymer is a water-soluble vinyl polymer having a carboxy group and specifically, is a polymer having a repeating unit derived from acrylic acid and/or methacrylic acid as the main chain and having a crosslinked structure of allyl sucrose or pentaerythritol (a crosslinked structure derived from the allyl sucrose or the pentaerythritol) formed by allyl ether or the like. In addition, this carboxyvinyl polymer may be a carboxyvinyl polymer salt.

Specific examples of the commercially available carboxyvinyl polymer include "CARBOPOL <NUM>", "CARBOPOL <NUM>", "CARBOPOL <NUM>", "CARBOPOL <NUM>", and "CARBOPOL <NUM>", which are manufactured by Lubrizol Advanced Materials Inc. ; "HIVISWAKO <NUM>", "HIVISWAKO <NUM>", and "HIVISWAKO <NUM>", which are manufactured by FUJIFILM Wako Pure Chemical Corporation; "Junron PW-<NUM>", "Junron PW-<NUM>", and "Junron PW-<NUM>", which are manufactured by TOAGOSEI CO. ; "AQUAPEC HV-501E" and "AQUAPEC HV-505E", which are manufactured by SUMITOMO SEIKA CHEMICALS CO. ; and "Synthalen K" and "Synthalen L" manufactured by 3V Sigma S.

In the biomaterial according to the embodiment of the present invention, one kind of the carboxyvinyl polymer may be used alone, or two or more kinds thereof may be used in combination.

A content of the carboxyvinyl polymer in the biomaterial according to the embodiment of the present invention is not particularly limited; however, it is preferably <NUM>% by mass to <NUM>% by mass, more preferably <NUM>% by mass to <NUM>% by mass, and still more preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the solid content of the biomaterial according to the embodiment of the present invention.

The biomaterial according to the embodiment of the present invention can further contain a non-aqueous dispersion medium.

The non-aqueous dispersion medium is not particularly limited as long as it is a non-aqueous medium capable of dispersing the at least one selected from the group consisting of a neutral acyl lipid, a phospholipid, and a quaternary ammonium salt, described above, and dispersing a carboxyvinyl polymer. The non-aqueous dispersion medium is preferably an alcohol having <NUM> or more carbon atoms and more preferably an alcohol having <NUM> to <NUM> carbon atoms.

Examples of the alcohol having <NUM> or more carbon atoms include heptyl alcohol (<NUM> carbon atoms), capryl alcohol (<NUM> carbon atoms), pelargonic alcohol (<NUM> carbon atoms), capric alcohol (<NUM> carbon atoms), lauryl alcohol (<NUM> carbon atoms), myristyl alcohol (<NUM> carbon atoms), oleyl alcohol (<NUM> carbon atoms), and stearyl alcohol (<NUM> carbon atoms).

In a case where the biomaterial according to the embodiment of the present invention includes the non-aqueous dispersion medium, the solid content in the biomaterial according to the embodiment of the present invention is not particularly limited; however, it is preferably <NUM>% by mass or more and preferably <NUM>% by mass or more. The upper limit is, for example, less than <NUM>% by mass.

The biomaterial according to the embodiment of the present invention may include other components as long as the effects of the present invention are not impaired, in addition to the at least one selected from the group consisting of a neutral acyl lipid, a phospholipid, and a quaternary ammonium salt, the carboxyvinyl polymer, and the non-aqueous dispersion medium, which are described above.

Examples of other components described above include sugar and sugar alcohol.

The sugar is not particularly limited; however, examples thereof include a monosaccharide and a disaccharide. Specific examples the sugar include glucose, galactose, sucrose, trehalose, and lactose.

The sugar alcohol is an organic compound having a structure in which the carbonyl group of aldose or ketose is reduced. Specific examples thereof include erythritol, xylitol, mannitol, and sorbitol, but the examples are not particularly limited.

The biomaterial according to the embodiment of the present invention forms a liquid crystal phase when being brought into contact with water. The water is not limited to pure water, and it may be water (aqueous moisture) contained in an aqueous fluid other than water. Examples of the aqueous fluid other than water include saliva, tissue fluid, blood, and lymph, but the examples are not limited thereto.

The amount of water which is brought into contact with the biomaterial according to the embodiment of the present invention is not particularly limited; however, it is preferably <NUM>% by mass to <NUM>,<NUM>% by mass and more preferably <NUM>% by mass to <NUM>% by mass, with respect to the total mass of the biomaterial according to the embodiment of the present invention.

Here, the liquid crystal phase is not particularly limited; however, it is usually any one phase selected from the group consisting of a lamellar (La) phase, a sponge (V2) phase, a hexagonal columnar (H2) phase, a bicontinuous cubic (L3) phase, or a cubic (Q) phase, and a mixed state of two or more thereof. The liquid crystal phase is preferably a lamellar phase, a hexagonal columnar phase, or a cubic phase. The temperature at which the biomaterial according to the embodiment of the present invention is brought into contact with water is not particularly limited; however, it is preferably <NUM> to <NUM> and more preferably <NUM> to <NUM>.

The biomaterial according to the embodiment of the present invention can be manufactured by mixing a neutral acyl lipid in which contents of a neutral monoacyl lipid and a neutral diacyl lipid are within a specific range; at least one selected from the group consisting of a phospholipid and a quaternary ammonium salt; a carboxyvinyl polymer; and, as desired, a non-aqueous dispersion medium.

The mixing method is not particularly limited, and a conventionally known mixing method can be used.

The biomaterial according to the embodiment of the present invention means a material that is used in a living body, and examples thereof include a material that is used in a living body, for example, for assisting or repairing a living body an original function of which has been lost or a living body a function of which has been deteriorated due to injury or disease.

The biomaterial according to the embodiment of the present invention can be used for mucous membrane protection, particularly preferably for oral cavity mucous membrane protection.

In a case where the biomaterial according to the embodiment of the present invention is used for a mucous membrane, when the biomaterial according to the embodiment of the present invention is placed on the mucous membrane and as necessary, water or a solution containing water is added thereon, the biomaterial according to the embodiment of the present invention absorbs water to form a liquid crystal phase, thereby strongly being attached to the mucous membrane.

In particular, in a case where the biomaterial according to the embodiment of the present invention is applied to the oral cavity mucous membrane, when the biomaterial according to the embodiment of the present invention is attached to the oral cavity mucous membrane, the liquid crystal phase is formed by the aqueous moisture in saliva, and thus is handling is easy. In addition, in a case where the amount of saliva is small, water or artificial saliva may be sprayed to supply aqueous moisture after the biomaterial according to the embodiment of the present invention is attached to the oral cavity mucous membrane.

In addition, the biomaterial according to the embodiment of the present invention can be preferably used for the sustained release of a drug. For example, a pharmaceutical pre-preparation is prepared by adding a drug to the biomaterial, and the pharmaceutical pre-preparation is brought into contact with water to form a liquid crystal phase, whereby the biomaterial can be used as a drug sustainedly-releasing base material.

Hereinafter, the present invention will be more specifically described according to Examples, but the present invention is not limited to Examples below.

A neutral acyl lipid (<NUM>-oleoyl-rac-glycerin (> <NUM>%), manufactured by Sigma-Aldrich Co. LLC; <NUM>) was mixed with a phospholipid (phosphatidylcholine (Lipoid S100, manufactured by Lipoid GmbH; <NUM>), and the mixture was heated and stirred at <NUM> for <NUM> hours until the mixture became a yellow transparent oily liquid (hereinafter, may be referred to as a "solid content A"). After weighing a carboxyvinyl polymer (Carbopol <NUM>, manufactured by Lubrizol Advanced Materials Inc. ; <NUM>), the carboxyvinyl polymer was dispersed in a non-aqueous dispersion medium (oleyl alcohol, manufactured by Tokyo Chemical Industry Co. ; <NUM>), the required amount of the solid content A (<NUM>) was added thereto, and then the resultant mixture was stirred at room temperature for <NUM> minutes to prepare a biomaterial.

Using the same preparation method, each component shown in Table <NUM> was mixed according to the blending amount shown in Table <NUM> to prepare biomaterials of Examples <NUM> to <NUM> and <NUM> to <NUM>, Reference Example <NUM> and Comparative Examples <NUM> to <NUM>.

Neutral acyl lipids (<NUM>), (<NUM>), (<NUM>), (<NUM>) and (<NUM>) are neutral acyl lipids according to the present invention, while neutral acyl lipids (<NUM>), (<NUM>) and (<NUM>) to (<NUM>) are not.

The prepared biomaterial (<NUM>µL) was placed on a slide glass, water (about <NUM>µL) was sprayed thereon from above, excess water was removed therefrom, covered with a cover glass, and then an initial observation was performed using a polarizing microscope (Nikon ECLIPSE E600 POL).

Thereafter, the biomaterial was heated together with the slide glass on a hot stage (INSTEC STC200) heated in advance to <NUM>, and the change in the liquid crystal phase was checked to identify the phase.

Tetradodecyl ammonium bromide (TDAB, manufactured by FUJIFILM Wako Pure Chemical Corporation; <NUM>), polyvinyl chloride (manufactured by FUJIFILM Wako Pure Chemical Corporation; <NUM>), and di-n-octylphosphonate (DOPP, manufactured by FUJIFILM Wako Pure Chemical Corporation; <NUM>) were dissolved in tetrahydrofuran (THF, FUJIFILM Wako Pure Chemical Corporation; <NUM>) and dried at room temperature with a petri dish to obtain a lipid membrane (about <NUM> thickness).

Next, the prepared lipid membrane was attached to a hydrogel consisting of agar (Karikorikan (registered trade mark), manufactured by Ina Food Industry Co. ; <NUM>), gellan gum (Kelcogel (registered trade mark), manufactured by CP Kelco; <NUM>), and distilled water (<NUM>).

Subsequently, the surface of the lipid membrane was coated with a <NUM>-methacryloyloxyethyl phosphorylcholine (MPC) polymer (LIPIDURE (registered trade mark) - CM5206, manufactured by NOF CORPORATION) to obtain a pseudo biological membrane.

The prepared biomaterial was applied onto the prepared pseudo biological membrane (<NUM> cmϕ, <NUM> thickness), artificial saliva (Saliveht (registered trade mark), manufactured by TEIJIN PHARMA LIMITED) was sprayed thereon, and the biomaterial was allowed to stand for <NUM> minute such that water was absorbed, thereby preparing a sample for evaluation.

The prepared sample for evaluation was placed in a petri dish and filled with artificial saliva (Saliveht) until the sample for evaluation was immersed. The petri dish was placed in a constant temperature shaker (<NUM>) and shaken such that the sample for evaluation was repeatedly hit to the wall of the petri dish. In this test, the time required for the biomaterial, which absorbed water from the pseudo biological membrane, to disappear by being peeled or dissolved from the pseudo biological membrane was measured, and the retention was evaluated according to the following criteria.

The evaluation results are shown in the "Evaluation" column of Table <NUM>.

The prepared sample for evaluation was repeatedly worn with a wear testing machine (surface property measuring machine TRIBOGEAR TYPE: 14FW, manufactured by Shinto Scientific Co. ), and the times of the reciprocation until the sample was peeled or dissolved from the pseudo biological membrane was measured, and scratch resistance was evaluated according to the following criteria. A triangular eraser core (Ain CLIC, manufactured by Pentel Co, Ltd,) was set on the head of the wear testing machine, and the test was performed under the conditions of a load of <NUM>, an amplitude of <NUM>, and a speed of <NUM>,<NUM>/min.

In Table <NUM>, "Mono/di/tri" indicates the content ratio (in terms of % by mass) between the neutral monoacyl lipid, the neutral diacyl lipid, and the neutral triacyl lipid in the neutral acyl lipid.

In Table <NUM>, "Mono + di" indicates the total content (in terms of % by mass) of the neutral monoacyl lipid and the neutral diacyl lipid in the neutral acyl lipid.

In Table <NUM>, each component is as follows.

In Table <NUM>, the types of the liquid crystal phase are represented by the following abbreviations.

The biomaterials of Examples <NUM>, <NUM>, <NUM> and <NUM> to <NUM> were good in retention and scratch resistance. Among them, from the comparison of Examples <NUM>, <NUM>, <NUM>, <NUM> and Reference Examples <NUM>, <NUM>, it has been confirmed that the case where the neutral acyl lipid contains both of the neutral monoacyl lipid and the neutral diacyl lipid exhibits more excellent effects. In addition, from the comparison of Examples <NUM> to <NUM>, it has been confirmed that the case where the total content of the phospholipid and the quaternary ammonium salt is <NUM>% by mass to <NUM>% by mass with respect to the total mass of the solid content of the biomaterial exhibits more excellent effects. Further, from the comparison of Examples <NUM>, <NUM>, and <NUM>, it has been confirmed that the case where a content of the carboxyvinyl polymer is <NUM>% by mass to <NUM>% by mass exhibits more excellent effects.

On the other hand, the biomaterials of Comparative Examples <NUM> to <NUM> had insufficient scratch resistance and could not exhibit retention and scratch resistance at the same time. Among them, Comparative Examples <NUM>, <NUM>, and <NUM> were insufficient in both the retention and the scratch resistance.

Claim 1:
A biomaterial comprising:
a neutral acyl lipid;
at least one selected from the group consisting of a phospholipid and a quaternary ammonium salt; and
a carboxyvinyl polymer,
wherein the neutral acyl lipid includes at least one selected from the group consisting of a neutral monoacyl lipid and a neutral diacyl lipid, and
a content of the at least one selected from the group consisting of the neutral monoacyl lipid and the neutral diacyl lipid is <NUM>% by mass to <NUM>% by mass with respect to a total mass of the neutral acyl lipid.