Thermochromic phase change bone cement and preparation method thereof

Abstract

The invention discloses thermochromic phase-change bone cement and a preparation method thereof.The thermochromic phase-change bone cement comprises a solid phase part and a liquid phase part, the solid phase part comprises an acrylate polymer, a developer, an initiator and a thermochromic phase-change material, and the thermochromic phase-change bone cement is characterized in that the liquid phase part comprises an acrylate polymer, a developer, an initiator and a thermochromic phase-change material; the thermochromic phase change material is a thermochromic phase change material packaged by expanded perlite; and the weight percentage of the thermochromic phase change material packaged by the expanded perlite in the solid phase part is 5-10%. The thermochromic phase change bone cement disclosed by the invention is low in temperature in the curing process, so that thermal damage to tissues around a use part can be reduced, complications caused by heating of the bone cement in the operation process are reduced, and the bone cement can be prompted to enter a curing period through color change; doctors can be helped to intuitively judge the polymerization reaction stage of the bone cement, and the method has very important clinical value.

Description

Technical Field

[0001] The invention belongs to the technical field of bone cement, and particularly relates to thermochromic phase change bone cement and a preparation method thereof. Background Art

[0002] Bone cement is the abbreviation of implantable medical devices made of polymethyl methacrylate (PMMA) as the main material, commonly known as acrylic resin bone cement or PMMA bone cement. It is usually a powder-liquid system composed of a polymer powder and a monomer liquid. The liquid is mainly composed of methyl methacrylate (MMA) monomer, and contains N,N-dimethyl-p-toluidine as an activator or co-initiator for free radical polymerization and a small amount of hydroquinone to prevent premature polymerization of the monomer. The powder can be composed of PMMA homopolymer or copolymer or a mixture of the two, and contains a small amount of benzoyl peroxide as a polymerization initiator and zirconium dioxide or barium sulfate as a developer.

[0003] The principle of using bone cement is that after mixing powder and liquid, bone cement will undergo a polymerization reaction, and the slurry will gradually change into a dough form, and then to a solid form. When bone cement is in the dough form, it has plasticity and can be filled into bone defects or bone cavities of different spatial shapes, or placed between human bones and implanted prostheses. When the dough form solidifies into a solid form, it can fill the defect and fix the prosthesis.

[0004] In the polymerization reaction of bone cement, there is a process where the carbon-carbon double bond breaks and is replaced by a single bond, which will generate polymerization heat. The generated polymerization heat will inevitably be transferred to the surrounding tissues. Bone tissue, collagen, nerve tissue, etc. are sensitive to temperature. If the heat is too high, thermal damage is likely to occur. In addition, the main stage in which bone cement generates polymerization heat during polymerization is the late stage of the polymerization reaction. Before the late stage of the polymerization reaction, the doctor must complete the filling of bone cement. However, the existing bone cement cannot accurately determine the degree of polymerization of bone cement by relying solely on the doctor's naked eye observation when using it. Therefore, how to judge whether bone cement has entered the late stage of polymerization and how to reduce the negative impact of the heat generated in the late stage of polymerization are issues that need to be solved urgently.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide thermochromic phase change bone cement and a preparation method thereof. The thermochromic phase change bone cement in the present invention can help doctors intuitively judge the polymerization reaction stage of bone cement through color changes, and the temperature will be greatly reduced during the curing process, reducing the possibility of damage to the surrounding tissues of the use site.

[0007] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0008] A thermochromic phase-change bone cement comprises a solid phase part and a liquid phase part, wherein the solid phase part comprises an acrylic polymer, a developer, an initiator and a thermochromic phase-change material, and the thermochromic phase-change material is a thermochromic phase-change material encapsulated by expanded perlite;

[0009] The weight percentage of the thermochromic phase change material encapsulated by the expanded pearlite in the solid phase is 5-10%.

[0010] In one or more embodiments of the present invention, the raw materials of the thermochromic phase change material include dye, phase change material and organic solvent, and the mass ratio of dye, phase change material and organic solvent is 1: (10-20): (10-50); and / or,

[0011] The mass ratio of the thermochromic phase change material to the expanded perlite is (70-85):(15-30).

[0012] In one or more embodiments of the present invention, the dye is crystal violet lactone; and / or,

[0013] The phase change material is one or more of stearic acid, palmitic acid, myristic acid, lauric acid, and capric acid; and / or,

[0014] The organic solvent is one or more of cetyl alcohol, heptadecanol and stearyl alcohol.

[0015] In one or more embodiments of the present invention, the particle size of the expanded perlite is 1.5-2.0 mm.

[0016] In one or more embodiments of the present invention, the mass ratio of the acrylic polymer, the developer, the initiator and the thermochromic phase change material encapsulated by expanded perlite is (50-80): (10-40): (0.1-5): (5-10).

[0017] In one or more embodiments of the present invention, the acrylic polymer is one or more of polymethyl methacrylate, styrene-methyl methacrylate copolymer or methyl acrylate-methyl methacrylate copolymer; and / or,

[0018] The particle size of the acrylic polymer is 20 to 200 μm; and / or,

[0019] The developer is one or both of zirconium dioxide and barium sulfate; and / or,

[0020] The initiator is benzoyl peroxide.

[0021] In one or more embodiments of the present invention, the liquid phase portion includes acrylate monomer, inhibitor and activator, and the volume ratio of the acrylate monomer, inhibitor and activator is (95-99): (0.05-1): (0.1-5).

[0022] In one or more embodiments of the present invention, the acrylate monomer is methyl methacrylate; and / or,

[0023] The polymerization inhibitor is one or both of hydroquinone and catechol; and / or,

[0024] The activator is one or two of N,N-dihydroxyethyl-p-methylaniline and N,N-dimethyl-p-toluidine.

[0025] Another specific embodiment of the present invention provides a technical solution as follows:

[0026] A method for preparing a thermochromic phase change bone cement comprises the following steps:

[0027] Mixing an acrylic polymer, a developer, an initiator and a thermochromic phase change material encapsulated by expanded perlite to obtain a solid phase, wherein the weight percentage of the thermochromic phase change material encapsulated by the expanded perlite in the solid phase is 5 to 10%;

[0028] Mixing the acrylic acid ester monomer, the polymerization inhibitor and the activator to obtain a liquid phase;

[0029] The solid phase part and the liquid phase part are mixed in a mass ratio of (2-3):1 to obtain a thermochromic phase-changing bone cement.

[0030] In one or more embodiments of the present invention, the preparation of the thermochromic phase change material encapsulated by expanded perlite is as follows:

[0031] Mixing the dye, the phase change material and the organic solvent to obtain a mixture;

[0032] The mixture is heated and melted in a vacuum environment, subjected to ultrasonic homogenization, and cooled in air until solid;

[0033] The solid and expanded perlite are mixed, vacuumed for 20 to 40 minutes, heated at 60 to 100° C. to melt the solid, the vacuum is turned off, and air reflux is used to compress the liquid attached to the surface of the expanded perlite into the internal pores of the expanded perlite to obtain a thermochromic phase change material encapsulated by the expanded perlite.

[0034] Compared with the prior art, the present invention adds thermochromic phase change material to bone cement, and uses the thermochromic phase change material to absorb the heat generated during the curing process of bone cement, effectively avoiding the possibility of thermal damage to the tissue around the use site, reducing complications caused by the heating of bone cement during surgery, and at the same time, the thermochromic phase change material will change color after absorbing heat, and the color change indicates that the bone cement has entered the curing period, which can help doctors intuitively judge the stage of bone cement polymerization reaction and facilitate clinical operation. In addition, the present invention selects expanded perlite to encapsulate the thermochromic phase change material, which has a good encapsulation effect and does not leak, can effectively absorb the heat generated by the curing of bone cement, and can effectively ensure the compressive strength of bone cement. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0036] During the polymerization process of bone cement, the carbon-carbon double bonds break and are replaced by single bonds, which will generate polymerization heat of 130 cal / g. Studies have shown that the heat generation range of commonly used brands of bone cement is 66-82.5°C, while bone tissue can necrotize at 50°C, collagen can deform at 56°C, and nerve tissue is more sensitive to temperature and can suffer bone damage at 43°C. Therefore, when bone cement is used to fix prostheses or fill bone defects, heat will inevitably be transferred to surrounding tissues, causing thermal damage.

[0037] Bone cement can be divided into four stages from the mixing of liquid and powder to the complete polymerization reaction, that is, complete solidification, which is the mixing period, waiting period, working period and solidification period. Mixing period: the process of mixing bone cement powder and liquid; waiting period: after the powder and liquid are mixed, there will be a period of time that is porridge-like or sticky or wire-drawn, and the user must wait until the bone cement is no longer sticky before working; working period: at this time, the state of bone cement is similar to dough, and the doctor can easily fill the bone cement; solidification period: the viscosity of bone cement increases rapidly and hardens and heats up, and bone cement filling must be completed before this period. Therefore, during clinical operations, it is very important to judge the timing of bone cement entering the solidification period.

[0038] Based on this, the present invention uses expanded perlite to encapsulate thermochromic phase change material and adds it to bone cement. The heat generated during the reaction of bone cement can be absorbed by the phase change material, so that the polymerization temperature is greatly reduced, which can effectively avoid thermal damage to the tissues around the use site. At the same time, when the bone cement generates heat during the curing period, the thermochromic phase change material can change color, thereby helping doctors intuitively judge the stage of bone cement polymerization reaction and facilitating clinical operations.

[0039] An embodiment of the present invention provides a thermochromic phase change bone cement, which includes a solid phase part and a liquid phase part. The solid phase part includes an acrylic polymer, a developer, an initiator and a thermochromic phase change material. The thermochromic phase change material is a thermochromic phase change material encapsulated by expanded perlite. The weight percentage of the thermochromic phase change material encapsulated by expanded perlite in the solid phase part is 5 to 10%.

[0040] Specifically, after absorbing heat, the phase change material will undergo a phase change from solid to liquid, absorb and store a large amount of latent heat during the melting process, and when cooling, the stored heat is dissipated into the environment within a certain temperature range, and a reverse phase change from liquid to solid occurs. The present invention uses expanded perlite to encapsulate thermochromic phase change materials. First, the morphological changes of the phase change material during the phase change process are avoided, which causes the volume of the bone cement to change, thereby ensuring the shape stability and mechanical stability of the bone cement; secondly, the expanded perlite has a large number of pores inside and has strong adsorption, and the phase change material can be encapsulated in the internal pores to prevent leakage; furthermore, the expanded perlite has good chemical stability and thermal stability, and can maintain structural stability in bone cement, which can help solve the problems of volume shrinkage and significant decrease in compressive strength of bone cement during the polymerization process, and the expanded perlite has good binding properties with the bone cement system, and can exist stably in the bone cement system; in addition, the expanded perlite is white or off-white, which is consistent with the color of bone cement, does not affect the color development effect, and is conducive to doctors observing the color change of bone cement.

[0041] Therefore, after the thermochromic phase change material encapsulated by expanded perlite is added to bone cement in a certain proportion, it can absorb the heat generated when the bone cement solidifies and reduce damage to surrounding tissues. Moreover, the thermochromic phase change material contains materials whose color changes due to temperature. The thermochromic phase change material encapsulated by expanded perlite changes color while absorbing heat, producing an indication effect, which helps doctors judge the stage of bone cement polymerization reaction.

[0042] In one embodiment, the raw materials of the thermochromic phase change material include a dye, a phase change material and an organic solvent, the mass ratio of the dye, the phase change material and the organic solvent is 1:(10-20):(10-50), the mass ratio of the thermochromic phase change material and the expanded perlite is (70-85):(15-30), the dye is crystal violet lactone, the phase change material is one or more of stearic acid, palmitic acid, myristic acid, lauric acid, and capric acid, and the organic solvent is one or more of cetyl alcohol, heptadecanol and stearyl alcohol.

[0043] Specifically, the opening and closing of the lactone ring in crystal violet lactone will cause color changes. At low temperatures, the lactone ring is colorless when closed, and blue or violet when heated. The above-mentioned types of phase change materials can effectively store and release energy, have good thermal and chemical stability, are not easy to decompose, and have high safety. The above-mentioned types of organic solvents can adjust the color change temperature, and have good chemical stability and high safety. By limiting the mass ratio of dyes, phase change materials and organic solvents, it can be ensured that the thermochromic phase change material changes color at the appropriate temperature, which helps to play an indicating role.

[0044] In one embodiment, the particle size of the expanded perlite is 1.5 to 2.0 mm.

[0045] Specifically, a suitable particle size helps the expanded perlite to encapsulate the thermochromic phase change material so that it is evenly dispersed in the bone cement system, and also helps to ensure the compressive strength of the bone cement. The smaller the particle size, the less the encapsulation amount of the thermochromic phase change material, which will affect the color change effect. The larger the particle size, the lower the compressive strength of the bone cement, which is not conducive to the filling effect of the bone cement.

[0046] In one embodiment, the mass ratio of the acrylate polymer, the developer, the initiator and the thermochromic phase change material encapsulated by expanded perlite is (50-80): (10-40): (0.1-5): (5-10), the acrylate polymer is one or more of polymethyl methacrylate, styrene-methyl methacrylate copolymer or methyl acrylate-methyl methacrylate copolymer, the particle size of the acrylate polymer is 20-200 μm, the developer is one or both of zirconium dioxide and barium sulfate, and the initiator is benzoyl peroxide.

[0047] In one embodiment, the liquid phase portion includes an acrylate monomer, an inhibitor and an activator, and the volume ratio of the acrylate monomer, the inhibitor and the activator is (95-99): (0.05-1): (0.1-5), the acrylate monomer is methyl methacrylate, the inhibitor is one or both of hydroquinone and catechol, and the activator is one or both of N,N-dihydroxyethyl-p-methylaniline and N,N-dimethyl-p-toluidine.

[0048] Specifically, by limiting the ratio of raw materials in the solid phase part and the liquid phase part, the bone cement exhibits better performance.

[0049] Another embodiment of the present invention provides a method for preparing thermochromic phase change bone cement, comprising steps 1-4.

[0050] Step 1, preparing a thermochromic phase change material encapsulated by expanded perlite.

[0051] Specifically, the dye, phase change material and organic solvent are ground and mixed in a mass ratio of 1: (10-20): (10-50) to obtain a mixture; the mixture is transferred to a culture dish, heated and melted at 60-100° C. in a vacuum oven, subjected to ultrasonic homogenization, and cooled in air to a solid; the solid and expanded perlite are mixed in a mass ratio of (70-85): (15-30), placed in a conical flask connected to a vacuum pump, evacuated for 20-40 minutes, and the conical flask is heated at 60-100° C. to completely melt the solid, the vacuum pump is turned off, and the liquid attached to the surface of the expanded perlite is pressed into the internal pores by air reflux to obtain a thermochromic phase change material encapsulated by the expanded perlite.

[0052] Step 2: Mix the acrylic polymer, developer, initiator and expanded perlite encapsulated thermochromic phase change material in a mass ratio of (50-80):(10-40):(0.1-5):(5-10) to obtain a solid phase part.

[0053] Step 3, mixing the acrylic acid ester monomer, the inhibitor and the activator in a volume ratio of (95-99): (0.05-1): (0.1-5) to obtain a liquid phase.

[0054] Step 4, mixing the solid phase part and the liquid phase part in a mass ratio of (2-3):1 to obtain thermochromic phase change bone cement.

[0055] The present invention is further described in detail below in conjunction with specific embodiments.

[0056] Example 1

[0057] Mix 5g of crystal violet lactone, 50g of stearic acid and 150g of cetyl alcohol, grind into powder in a mortar, transfer to a petri dish, and heat to melt in a vacuum oven at 80°C. The sample is homogenized by ultrasound and cooled in air until solid. Mix 80g of the solid with 20g of expanded perlite with a particle size of 1.5-2.0mm, place in a conical flask connected to a vacuum pump, evacuate for 20min, heat the conical flask at 80°C to completely melt the solid, then turn off the vacuum pump, and use air reflux to compress the liquid attached to the surface of the expanded perlite into the internal pores of the expanded perlite to obtain a thermochromic phase change material encapsulated by expanded perlite.

[0058] 65 g of polymethyl methacrylate, 1.5 g of benzoyl peroxide, 5 g of thermochromic phase change material encapsulated by expanded perlite and 28.5 g of zirconium dioxide powder were mixed uniformly to obtain a solid phase part.

[0059] 98 ml of methyl methacrylate monomer, 1.9 ml of N,N-dimethyl-p-toluidine and 0.1 ml of hydroquinone were mixed evenly, and the mixture was sterile filtered and filled to obtain the liquid phase.

[0060] The solid phase part and the liquid phase part are mixed at a weight ratio of 2:1 to obtain thermochromic phase-changing bone cement.

[0061] Example 2

[0062] Mix 5g of crystal violet lactone, 50g of stearic acid and 200g of stearyl alcohol, grind into powder in a mortar, transfer to a petri dish, and heat to melt in a vacuum oven at 80°C. The sample is homogenized by ultrasound and cooled in air until solid. Mix 85g of the solid with 15g of expanded perlite with a particle size of 1.5-2.0mm, place in a conical flask connected to a vacuum pump, evacuate for 30 minutes, heat the conical flask at 80°C to completely melt the solid, then turn off the vacuum pump, and use air reflux to press the liquid attached to the surface of the expanded perlite into the internal pores of the expanded perlite to obtain a thermochromic phase change material encapsulated by expanded perlite.

[0063] 60 g of styrene-methyl methacrylate copolymer, 1.0 g of benzoyl peroxide, 10 g of thermochromic phase change material encapsulated by expanded perlite and 29 g of barium sulfate powder were mixed uniformly to obtain a solid phase part.

[0064] 98 ml of methyl methacrylate monomer, 1.9 ml of N,N-dimethyl-p-toluidine and 0.1 ml of hydroquinone were mixed evenly, and the mixture was sterile filtered and filled to obtain the liquid phase.

[0065] The solid phase part and the liquid phase part are mixed at a weight ratio of 2:1 to obtain thermochromic phase-changing bone cement.

[0066] Example 3

[0067] Mix 5g of crystal violet lactone, 50g of lauric acid and 150g of cetyl alcohol, grind into powder in a mortar, transfer to a petri dish, and heat to melt in a vacuum oven at 80°C. The sample is homogenized by ultrasound and cooled in air until solid. Mix 80g of the solid with 15g of expanded perlite with a particle size of 1.5-2.0mm, place in a conical flask connected to a vacuum pump, evacuate for 20 minutes, heat the conical flask at 80°C to completely melt the solid, then turn off the vacuum pump, and use air reflux to press the liquid attached to the surface of the expanded perlite into the internal pores of the expanded perlite to obtain a thermochromic phase change material encapsulated by expanded perlite.

[0068] 65 g of polymethyl methacrylate, 1.5 g of benzoyl peroxide, 5 g of thermochromic phase change material encapsulated by expanded perlite and 28.5 g of zirconium dioxide powder were mixed uniformly to obtain a solid phase part.

[0069] 98 ml of methyl methacrylate monomer, 1.9 ml of N,N-dimethyl-p-toluidine and 0.1 ml of hydroquinone were mixed evenly, and the mixture was sterile filtered and filled to obtain the liquid phase.

[0070] The solid phase part and the liquid phase part are mixed at a weight ratio of 2:1 to obtain thermochromic phase-changing bone cement.

[0071] Comparative Example 1

[0072] 70 g of styrene-methyl methacrylate copolymer, 1.5 g of benzoyl peroxide and 28.5 g of barium sulfate powder were mixed uniformly to obtain a solid phase.

[0073] 98 ml of methyl methacrylate monomer, 1.9 ml of N,N-dimethyl-p-toluidine and 0.1 ml of hydroquinone were mixed evenly, and the mixture was sterile filtered and filled to obtain the liquid phase.

[0074] The solid phase part and the liquid phase part are mixed at a weight ratio of 2:1 to obtain thermochromic phase-changing bone cement.

[0075] Comparative Example 2

[0076] Mix 5g of crystal violet lactone, 50g of stearic acid and 200g of stearyl alcohol, grind into powder in a mortar, transfer to a petri dish, and heat to melt in a vacuum oven at 80°C. The sample is homogenized by ultrasound and cooled in air until solid. Mix 85g of the solid with 15g of expanded perlite with a particle size of 1.5-2.0mm, place in a conical flask connected to a vacuum pump, evacuate for 30 minutes, heat the conical flask at 80°C to completely melt the solid, then turn off the vacuum pump, and use air reflux to press the liquid attached to the surface of the expanded perlite into the internal pores of the expanded perlite to obtain a thermochromic phase change material encapsulated by expanded perlite.

[0077] 55 g of styrene-methyl methacrylate copolymer, 1.5 g of benzoyl peroxide, 15 g of thermochromic phase change material encapsulated by expanded perlite and 28.5 g of barium sulfate powder were mixed uniformly to obtain a solid phase part.

[0078] 98 ml of methyl methacrylate monomer, 1.9 ml of N,N-dimethyl-p-toluidine and 0.1 ml of hydroquinone were mixed evenly, and the mixture was sterile filtered and filled to obtain the liquid phase.

[0079] The solid phase part and the liquid phase part are mixed at a weight ratio of 2:1 to obtain thermochromic phase-changing bone cement.

[0080] Comparative Example 3

[0081] 5g of crystal violet lactone, 50g of stearic acid and 150g of cetyl alcohol were mixed, ground into powder in a mortar, transferred to a petri dish, and heated to melt in a vacuum oven at 80°C. The sample was homogenized by ultrasound and cooled in air until solid. 80g of the solid was mixed with 20g of expanded perlite with a particle size of 5mm, placed in a conical flask connected to a vacuum pump, evacuated for 20min, and the conical flask was heated at 80°C to completely melt the solid, then the vacuum pump was turned off, and the air reflux was used to press the liquid attached to the surface of the expanded perlite into the internal pores of the expanded perlite to obtain the thermochromic phase change material encapsulated by the expanded perlite.

[0082] 60 g of styrene-methyl methacrylate copolymer, 1.0 g of benzoyl peroxide, 10 g of thermochromic phase change material encapsulated by expanded perlite and 29 g of barium sulfate powder were mixed uniformly to obtain a solid phase part.

[0083] 98 ml of methyl methacrylate monomer, 1.9 ml of N,N-dimethyl-p-toluidine and 0.1 ml of hydroquinone were mixed evenly, and the mixture was sterile filtered and filled to obtain the liquid phase.

[0084] The solid phase part and the liquid phase part are mixed at a weight ratio of 2:1 to obtain thermochromic phase-changing bone cement.

[0085] Comparative Example 4

[0086] Mix 5g of crystal violet lactone, 50g of stearic acid and 150g of cetyl alcohol, grind into powder in a mortar, transfer to a petri dish, and heat to melt in a vacuum oven at 80°C. The sample is homogenized by ultrasound and cooled in air until solid. Mix 80g of the solid with 20g of diatomaceous earth with a particle size of 1.5-2.0mm, place in a conical flask connected to a vacuum pump, evacuate for 20min, heat the conical flask at 80°C to completely melt the solid, then turn off the vacuum pump, and use air reflux to press the liquid attached to the surface of the diatomaceous earth into the internal pores of the diatomaceous earth to obtain a diatomaceous earth-encapsulated thermochromic phase change material.

[0087] 65 g of polymethyl methacrylate, 1.5 g of benzoyl peroxide, 5 g of diatomaceous earth-encapsulated thermochromic phase change material and 28.5 g of zirconium dioxide powder were mixed uniformly to obtain a solid phase part.

[0088] 98 ml of methyl methacrylate monomer, 1.9 ml of N,N-dimethyl-p-toluidine and 0.1 ml of hydroquinone were mixed evenly, and the mixture was sterile filtered and filled to obtain the liquid phase.

[0089] The solid phase part and the liquid phase part are mixed at a weight ratio of 2:1 to obtain thermochromic phase-changing bone cement.

[0090] The mechanical properties, maximum temperature and color change properties of the thermochromic phase change bone cement in each embodiment and each comparative example were tested:

[0091] (1) At an ambient temperature of 23±1℃, the solid phase and the liquid phase were mixed in a bone cement mixing bowl at a mass ratio of 2:1 for 30 seconds. According to YY 0459 "Acrylic Resin Bone Cement for Surgical Implants", the specimens were molded in a stainless steel mold with a diameter of 6 mm and a height of 12 mm. The specimens were kept at a constant temperature of 23±1℃ for 24 hours and tested using a mechanical testing machine at a crosshead displacement rate of 20 mm / min. The compressive strength was obtained from the load-displacement curve.

[0092] (2) At an ambient temperature of 23±1℃, the solid phase and the liquid phase were mixed in a bone cement mixing bowl at a mass ratio of 2:1 for 30 seconds. According to YY 0459 "Acrylic Resin Bone Cement for Surgical Implants", the maximum temperature of the bone cement during curing was tested using a thermocouple. The color change of the bone cement during curing was observed as the bone cement rose from ambient temperature to the maximum temperature and then returned to ambient temperature (ambient temperature → maximum temperature → ambient temperature).

[0093] Table 1 Thermochromic phase change bone cement performance test results

[0094]

[0095]

[0096] As can be seen from Table 1, the maximum temperature of the bone cement without adding thermochromic phase change material in Comparative Example 1 during the curing process reaches 72°C, which has reached a temperature that is easy to cause thermal damage to tissues, easily causing complications, and has low safety. The amount of thermochromic phase change material added in Comparative Example 2 is too high. Although the maximum temperature of the bone cement during the curing process is appropriate, the compressive strength of the bone cement is low, which is not conducive to its supporting role in the filling part. The maximum temperature of the bone cement in the embodiments of the present invention during the curing process is less than 45°C, which can reduce the complications caused by the heating of the bone cement during the operation, and the compressive strength is greater than 70MPa, which can provide sufficient strength to maintain a stable connection and long-term fixation of the prosthesis. In addition, the color of the bone cement will change from white, blue, and white during the curing process, which can indicate to the doctor to judge the polymerization reaction stage of the bone cement, thereby improving the convenience of clinical operation.

[0097] In Comparative Example 3, expanded perlite with a particle size of 5 mm was used to encapsulate the thermochromic phase change material. Although the maximum temperature of the bone cement was suitable, the compressive strength of the bone cement was low and did not meet the compressive strength requirement (≥70 MPa) of YY 0459 "Acrylic Resin Bone Cement for Surgical Implants".

[0098] In Comparative Example 4, diatomite is used to encapsulate the thermochromic phase change material. Although the compressive strength of the prepared bone cement is barely suitable, the highest temperature during the curing process reaches 55°C. The high temperature is prone to cause complications and is not suitable for clinical surgery. Analysis shows that compared with expanded perlite, diatomite has a poorer encapsulation effect on thermochromic phase change materials. After being added to bone cement, although it can also absorb heat and reduce the temperature of bone cement, the temperature reduction effect cannot meet the expected use requirements.

[0099] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0100] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A thermochromic phase change bone cement, comprising a solid phase part and a liquid phase part, wherein the solid phase part comprises an acrylic polymer, a developer, an initiator and a thermochromic phase change material, characterized in that: The thermochromic phase change material is a thermochromic phase change material encapsulated by expanded perlite; The weight percentage of the thermochromic phase change material encapsulated by the expanded pearlite in the solid phase is 5-10%.

2. The thermochromic phase change bone cement according to claim 1, characterized in that: The raw materials of the thermochromic phase change material include dye, phase change material and organic solvent, and the mass ratio of dye, phase change material and organic solvent is 1: (10-20): (10-50); and / or, The mass ratio of the thermochromic phase change material to the expanded perlite is (70-85):(15-30).

3. The thermochromic phase change bone cement according to claim 2, characterized in that: The dye is crystal violet lactone; and / or, The phase change material is one or more of stearic acid, palmitic acid, myristic acid, lauric acid, and capric acid; and / or, The organic solvent is one or more of cetyl alcohol, heptadecanol and stearyl alcohol.

4. The thermochromic phase change bone cement according to claim 1, characterized in that: The particle size of the expanded perlite is 1.5-2.0 mm.

5. The thermochromic phase change bone cement according to claim 1, characterized in that: The mass ratio of the acrylic polymer, the developer, the initiator and the thermochromic phase change material encapsulated by the expanded perlite is (50-80): (10-40): (0.1-5): (5-10).

6. The thermochromic phase change bone cement according to claim 1, characterized in that: The acrylic polymer is one or more of polymethyl methacrylate, styrene-methyl methacrylate copolymer or methyl acrylate-methyl methacrylate copolymer; and / or, The particle size of the acrylic polymer is 20 to 200 μm; and / or, The developer is one or both of zirconium dioxide and barium sulfate; and / or, The initiator is benzoyl peroxide.

7. The thermochromic phase change bone cement according to claim 1, characterized in that: The liquid phase part includes acrylate monomer, inhibitor and activator, and the volume ratio of the acrylate monomer, inhibitor and activator is (95-99): (0.05-1): (0.1-5).

8. The thermochromic phase change bone cement according to claim 7, characterized in that: The acrylate monomer is methyl methacrylate; and / or, The polymerization inhibitor is one or both of hydroquinone and catechol; and / or, The activator is one or two of N,N-dihydroxyethyl-p-methylaniline and N,N-dimethyl-p-toluidine.

9. A method for preparing the thermochromic phase change bone cement according to any one of claims 1 to 8, characterized in that: The following steps are involved: Mixing an acrylic polymer, a developer, an initiator and a thermochromic phase change material encapsulated by expanded perlite to obtain a solid phase, wherein the weight percentage of the thermochromic phase change material encapsulated by the expanded perlite in the solid phase is 5 to 10%; Mixing the acrylic acid ester monomer, the polymerization inhibitor and the activator to obtain a liquid phase; The solid phase part and the liquid phase part are mixed in a mass ratio of (2-3):1 to obtain a thermochromic phase-changing bone cement.

10. The method for preparing the thermochromic phase change bone cement according to claim 9, characterized in that: The preparation of the thermochromic phase change material encapsulated by expanded perlite is as follows: Mixing the dye, the phase change material and the organic solvent to obtain a mixture; The mixture is heated and melted in a vacuum environment, subjected to ultrasonic homogenization, and cooled in air until solid; The solid and expanded perlite are mixed, vacuumed for 20 to 40 minutes, heated at 60 to 100° C. to melt the solid, the vacuum is turned off, and air reflux is used to compress the liquid attached to the surface of the expanded perlite into the internal pores of the expanded perlite to obtain a thermochromic phase change material encapsulated by the expanded perlite.

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