CN116196482A - A kind of antibacterial bone cement modified by dimethylaminotriclosan methacrylate - Google Patents

Abstract

The invention discloses an antibacterial bone cement modified by dimethylaminotriclosan methacrylate. The raw materials include powder and liquid, and the powder includes the following components in mass percentage: 82.10%-94.30% polymethyl methacrylate Microspheres, 0.70% to 2.90% of initiator, 5.00% to 15.00% of developer, the liquid includes the following components in mass ratio: 58.32% to 94.62% of methyl methacrylate, 0.40% to 2.00% of Catalyst, 4.98%～39.68% dimethylaminotriclosan methacrylate; the novel antibacterial bone cement of the present invention obtains antibacterial ability through the quaternary ammonium group in dimethylaminotriclosan methacrylate, and realizes antibacterial effect on Gram Positive and negative bacteria and fungi can be effectively bacteriostatic and sterilized, showing good broad-spectrum antibacterial properties, and are suitable as an alternative filling material for vertebral body and kyphoplasty, and hip (knee) joint replacement.

Description

A kind of antibacterial bone cement modified by dimethylaminotriclosan methacrylate

technical field

The invention relates to the field of biomedical polymer materials, in particular to a novel methyl methacrylate (PMMA) bone cement which is modified by methacrylic acid quaternary ammonium salt monomer to obtain antibacterial ability.

Background technique

Antimicrobial polymethyl methacrylate bone cement (PMMA bone cement) is constructed on the basis of plain bone cement by adding antibiotics such as gentamicin sulfate and vancomycin to the powder side An implant material with self-curing properties. Antibacterial PMMA bone cement has a certain rheology and plasticity before curing, and is easy to fill in complex surgical sites; after curing, it can support the joint prosthesis and transmit loads. These properties meet the requirements of vertebral body and kyphoplasty, hip (knee) joint replacement for filling materials, so PMMA bone cement is widely used to treat spinal compression fractures and fix joint prostheses.

After years of clinical application, it has been found that antibacterial PMMA bone cement has poor antibacterial performance, which will cause malignant symptoms such as bacterial inflammation, wound infection and pus in patients undergoing transplantation. The reasons can be summarized as follows: (1) After the bone cement is solidified, its internal structure is dense, and only the antibiotics distributed on the surface can be released, while the antibiotics inside the bone cement lose their antibacterial effect due to the lack of release channels; (2) After implantation, the antibiotics on the surface are released too quickly, and the internal antibiotics cannot be further released, and the bone cement cannot achieve mid- and long-term sterilization due to the lack of a "slow release" mechanism; (3) What is more serious is that the heat generated by MMA polymerization makes the bone cement When the temperature is raised to 80-120°C for a short period of time, it will cause partial or even complete "inactivation" of antibiotics. Generally speaking, antibiotics themselves are not suitable for PMMA/MMA bone cement systems, and finding new antibacterial agents to replace antibiotics has become an urgent problem to be solved for antibacterial bone cements.

Inorganic antibacterial materials in new antibacterial agents have the advantages of no drug resistance, broad spectrum, long-term antibacterial and high safety. Typical representatives are silver (Ag), copper (Cu), gold (Au) and zinc oxide (ZnO). , (titanium oxide) TiO ₂ and so on. The researchers added it to PMMA bone cement and indeed played a significant antibacterial and antibacterial effect. For example, the modified bone cement added with Ag, Cu, AgCu, and Ni nanoparticles confirmed that the modified bone cement can reduce the number of eukaryotic cells in direct contact with bacteria in the test of bacterial viability after 6 months, But only the modified bone cement containing Ag and Cu had no bacteria, while the surface of the modified bone cement added with AgCu and Ni showed bacteria aggregated to form biofilm. The modified bone cement loaded with 1% nano-Au particles reduced the number of live bacteria of methicillin-resistant Staphylococcus aureus and Pseudomonas by 54% and 56%, respectively, and the biofilm thickness decreased by 74%, showing excellent performance. antibacterial activity. However, modified bone cements with inorganic antibacterial materials as additives still face the same problems as antibiotics. Due to the tight structure of PMMA bone cement after curing, the lack of release channels for internal antibacterial nanoparticles and poor mid- and long-term bactericidal effects are also exposed. .

purpose of invention

In view of the problems existing in the prior art, the present invention proposes to add an organic antibacterial agent from one end of the liquid to solve the above problems. The present invention selects dimethylaminoethyl methacrylate which can be miscible with MMA and can be copolymerized when encountering free radicals. Ester (DMAEMA), and antibacterial triclosan (Triclosan) are used as raw materials, and the two are combined into methacrylic acid with both antibacterial quaternary ammonium structure and unsaturated C=C double bond through Menster gold reaction Quaternary ammonium salt monomer, i.e. dimethylaminotriclosan methacrylate (DMAPPA), has good antibacterial and bactericidal effect and broad-spectrum antibacterial activity; The quaternary ammonium group realizes the antibacterial of the bone cement. On the other hand, the unsaturated C=C double bond is used to participate in the polymerization of MMA, so as to avoid the negative impact of the added materials on the physical and chemical properties of the matrix, so that the performance indicators of the antibacterial bone cement can meet the requirements of the vertebral body and posterior vertebral body. It can be used as a substitute for the current commercial antibacterial PMMA bone cement for the relevant requirements of surgery such as convex plastic surgery and hip (knee) replacement.

The invention provides an antibacterial bone cement modified by dimethylaminotriclosan methacrylate (DMAPPA). Antibacterial ability, and use the unsaturated C=C double bond of DMAPPA to participate in MMA polymerization to ensure that the compressive strength, flexural strength and flexural elastic modulus of the modified bone cement are all higher than the lower limit requirements of the international standard ISO5833; By adjusting the amount of DMAPPA added, the modified bone cement has the advantages of low curing maximum exothermic temperature and no cytotoxicity. It is suitable as a filling material for vertebral body and kyphoplasty, hip (knee) joint replacement, used to replace the current commercial antibacterial PMMA bone cement, and can be used for vertebral body and kyphoplasty, hip (knee) joint replacement Alternative filler material for replacement.

Technical scheme of the present invention is as follows:

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate, the raw materials include powder and liquid, and the powder includes the following components in mass percentage: 82.10% to 94.30% polymethylmethacrylate (PMMA) Microspheres, 0.70% to 2.90% of the initiator, 5.00% to 15.00% of the developer, and the liquid includes the following components by mass ratio: 58.32% to 94.62% of methyl methacrylate (MMA), 0.40% to 2.00% catalyst, 4.98%-39.68% dimethylaminotriclosan methacrylate (DMAPPA).

The mass ratio of powder and liquid in the raw materials is 1.0-3.0 g/g.

The weight-average molecular weight _Mw of the polymethyl methacrylate microsphere is 50000-120000, the number-average molecular weight _Mn is 25000-96000, and the size of the microsphere is 7-38 μm.

The initiator is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is one of zirconia (ZrO ₂ ) or barium sulfate (BaSO ₄ ). .

Described dimethylaminotriclosan methacrylate (DMAPPA) is an antibacterial additive material, and the concrete steps of its preparation method are as follows:

(1) Weigh raw materials dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan);

(2) The two raw materials weighed in step (1) are added to absolute ethanol to be mixed with a mixed solution;

(3) After the mixed solution of step (2) is sealed, carry out the Mensterkin reaction under the assistance of magnetic stirring;

(4) Transfer the mixed solution after the reaction of step (3) to an evaporator for de-ethanol treatment. After the ethanol is completely evaporated, a transparent viscous dimethylaminotriclosan methacrylate (DMAPPA) liquid is obtained;

The molar ratio of step (1) DMAEMA and Triclosan is 1:1.

The concentration of the mixed solution in step (2) is 3.2-3.5 mol/L, that is, the total concentration of the solute in the solution (the total concentration of the sum of dimethylaminoethyl methacrylate (DMAEMA) and triclosan).

Step (3) The temperature of the Misterkin reaction is 40-70° C., the reaction time is 4-24 hours, and the rotational speed of the magnetic stirring magnet is 800-1400 rpm.

The novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate of the present invention, its preparation method is as follows: After the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the liquid is weighed according to the proportion of the raw materials. After taking it, keep stirring with a magnet until it is uniform, and after mixing the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

The beneficial effects of the present invention are as follows:

1, the present invention is synthesized by the dimethylaminotriclosan methacrylate (DMAPPA) monomer of Munster gold method, and its structure has quaternary ammonium group and unsaturated C=C double bond simultaneously, and quaternary ammonium group is to pathogenic bacterium It has bactericidal and antibacterial effects, and can endow the modified new bone cement with antibacterial ability; the unsaturated C=C double bond can participate in the MMA polymerization reaction under the initiation/catalysis of BPO/DmpT, and become a part of the PMMA main chain, thereby avoiding The negative impact of additives on the physical and chemical properties of the matrix.

2. The present invention regulates the yield, structure and viscosity of the DMAPPA monomer by regulating the concentration of the mixed solution, the Munster gold reaction temperature, the reaction time and the stirring speed, and then regulates the mass percentage and the powder of each component of the powder and the liquid. The new type of antibacterial bone cement is regulated by liquid mixing ratio, PMMA microsphere molecular weight and particle size, so that it shows better broad-spectrum antibacterial and antibacterial activity, mechanical properties that can meet the lower limit requirements of ISO5833, and lower curing maximum radiation. Advantages such as thermal temperature and non-cytotoxicity.

3. The DMAPPA monomer synthesized by the Munster Gold method in the present invention is tested for the inhibition zone of Staphylococcus aureus, Escherichia coli and Candida albicans by soaking the Φ6mm×1mm drug-sensitive tablet, and the diameter of the inhibition zone is greater than 6mm , followed by 35.01±0.11～40.27±0.23mm, 30.21±0.43～36.13±0.57mm and 25.64±0.35～34.85±0.45mm, showing a good broad-spectrum antibacterial ability under the action of quaternary ammonium groups.

4. The DMAPPA monomer synthesized by the Munster Gold method in the present invention is water-soluble under the joint action of quaternary ammonium groups and chloride ions; when added to bone cement as a modified component, it will become a part of the PMMA main chain and exist in the The surface of the bone cement makes the contact angle of the antibacterial modified bone cement range from 51.5±2.7° to 73.3±2.3°, showing better hydrophilicity, and the contact angle further decreases with the content of DMAPPA monomer in the bone cement.

5. The compressive strength, flexural strength and flexural elastic modulus of the new antibacterial bone cement of the present invention can all be higher than the average compressive strength ≥ 70 MPa, the average flexural strength ≥ 50 MPa, and the average flexural modulus ≥ 1.8 specified in ISO5833 The lower limit index of GPa; and under the action of DMAPPA unsaturated C=C double bond participating in MMA polymerization, the mechanical properties of PMMA bone cement can be further improved.

6. Both the curing time and the maximum exothermic temperature of the new antibacterial bone cement of the present invention meet the requirements of the international standard ISO5833, that is, when used in the form of dough, the curing time ranges from 3 to 15 minutes, and the maximum curing exothermic temperature is ≤90±5°C; DMAPPA partially replaces MMA, which can further reduce the maximum exothermic temperature of curing.

7. The new antibacterial bone cement of the present invention is cut into 10×10×1mm ³ samples to test the antibacterial zone of Staphylococcus aureus, Escherichia coli, and Candida albicans, and the diameter of the antibacterial zone is 30.94～40.76±3.82mm respectively , 20.34～30.44±3.07mm and 10.33±0.57～14.35±0.38mm, showing good broad-spectrum antibacterial ability.

8. The new type of antibacterial bone cement of the present invention, mouse embryonic osteoblast precursor cells (MC3T3-E1 cells) are cultured in its extract for 24h and 72h, and its cell relative proliferation rate (RGR) is 72.3% to 99.3% According to ISO10993, its toxicity grades are grade 0 and grade 1, and the new antibacterial bone cement has no cytotoxicity.

9. The new antibacterial bone cement of the present invention has the advantages of no cytotoxicity, good mechanical properties and curing performance, and its antibacterial activity can reduce the probability of bacterial inflammation of the implant in the human body, so as to prolong the service life of the joint prosthesis, The purpose of avoiding repeated treatment is suitable for the treatment of spinal compression fractures and fixed joint prosthesis, and can be used as an alternative filling material for vertebral body and kyphoplasty and hip (knee) joint replacement.

Description of drawings

Fig. 1 is the proton nuclear magnetic spectrogram ( ^1HNMR ) (a) of the raw material DMAEMA and Triclosan of the embodiment 1 of the present invention, process product DMAPPA (a) and the schematic diagram (b) of the Munster gold reaction equation;

Fig. 2 is the hydrogen nuclear magnetic spectrum ( ¹ HNMR) of the bone cement of Example 2 of the present invention;

Fig. 3 is the optical photograph of the inhibition zone of Staphylococcus aureus, Escherichia coli and Candida albicans 3 kinds of bacteria tests of DMAPPA prepared in embodiment 3 of the present invention under the disc diffusion method;

Fig. 4 is the optical photograph when the simulated human body fluid (SBF) liquid droplet of embodiment 4 of the present invention tests the contact angle of the bone cement when it falls on the surface of the bone cement;

Fig. 5 is the compressive stress-strain curve (a) and the bending stress-strain curve (b) of the bone cement of Example 5 of the present invention;

Fig. 6 is the curing temperature-time curve of the bone cement of Example 6 of the present invention;

7 is an optical photo of the antibacterial zone of Staphylococcus aureus, Escherichia coli and Candida albicans under the disc diffusion method of the new antibacterial bone cement according to Example 7 of the present invention;

Fig. 8 shows the cell activity of MC3T3-E1 cells cultured in the new antibacterial bone cement extract of Example 8 for 24 hours and 72 hours.

Detailed ways

The following examples are a series of detailed descriptions aimed at the material characteristics and preparation methods of the present invention, which should not be construed as limiting the claims of the present invention. It should also be pointed out that several replacements and improvements made without departing from the concept of the present invention all belong to the protection scope of the present invention.

Example 1

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate, raw materials include powder and liquid, the powder contains 82.10% polymethyl methacrylate (PMMA) microspheres, 2.90% of Initiator, 15.00% developer, liquid contains 58.80% methyl methacrylate (MMA), 2.00% catalyst, 39.20% dimethylaminotriclosan methacrylate (DMAPPA) by mass percentage.

The polymethyl methacrylate (PMMA) microspheres used in this example have a weight-average molecular weight _Mw in the range of 50000-120000, a number-average molecular weight _Mn in the range of 25000-96000, and a microsphere size in the range of 7-38 μm.

The initiator selected in this embodiment is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is zirconia (ZrO ₂ ).

Dimethylaminotriclosan methacrylate (DMAPPA) in the present embodiment is synthesized by the Menster Gold method, and its main preparation steps are as follows:

(1) Weigh two raw materials of dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan) in a molar ratio of 1:1;

(2) Add the two raw materials weighed in step (1) to ethanol, and prepare a mixed solution at a concentration of 3.5mol/L;

(3) After sealing the mixed solution of step (2), carry out the Mönstergold reaction under the assistance of magnetic stirring, the Mönstergold reaction temperature is 70°C, the reaction time is 4h, and the magneton speed is 800rpm;

(4) Transfer the mixed solution after the reaction in step (3) to an evaporator for de-ethanol treatment, and evaporate for more than 24 hours. After the ethanol is completely evaporated, a transparent viscous DMAPPA liquid is obtained.

The preparation method of the novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate in this example is as follows: after the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the mass ratio of the powder to the liquid is Weigh the liquid at 3.0g/g, stir continuously with a magnet until uniform, mix the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

The hydrogen nuclear magnetic spectrum (1HNMR) of dimethylaminotriclosan methacrylate (DMAPPA) and its raw materials DMAEMA and Triclosan produced in this embodiment is shown in Figure ¹ , as shown in Figure 1, as shown in Figure 1: 6.5-7.5ppm The signal of benzene ring appears between 5.5ppm and 6ppm, the signal of carbon-carbon double bond, and the signal of methyl group connected to N appears at 3.7ppm, which shows that DMAPPA and Triclosan have undergone quaternization, so that the benzene ring in Triclosan lacks Cl and becomes an electron-withdrawing group, the shielding effect is reduced, and the chemical shift moves to the lower field, so that the hydrogen at the e position in DMAEMA is shifted to the a position in DMAPPA; according to the results in Figure 1(a), it can be concluded that the Mensterkin between the two raw materials Reaction equation, the schematic diagram of its reaction equation is as shown in Figure 1 (b), as can be seen from Figure 1 (b), the reaction occurs at the nitrogen position, DMAPPA is connected with Triclosan by quaternization and finally forms the product dimethylaminomethacrylate Triclosan ester (DMAPPA).

Example 2

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate, raw materials include powder, liquid, powder contains 94.30% polymethylmethacrylate (PMMA) microspheres, 0.70% of Initiator, 5.00% developer, liquid contains 58.32% methyl methacrylate (MMA), 2.00% catalyst, 39.68% dimethylaminotriclosan methacrylate (DMAPPA) by mass percentage.

The polymethyl methacrylate (PMMA) microspheres used in this example have a weight-average molecular weight _Mw in the range of 50000-120000, a number-average molecular weight _Mn in the range of 25000-96000, and a microsphere size in the range of 7-38 μm.

The initiator selected in this embodiment is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is barium sulfate (BaSO ₄ ).

Dimethylaminotriclosan methacrylate (DMAPPA) in the present embodiment is synthesized by the Menster Gold method, and its main preparation steps are as follows:

(1) Weigh two raw materials of dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan) in a molar ratio of 1:1;

(2) Add the two raw materials weighed in step (1) into ethanol, and prepare a mixed solution at a concentration of 3.2mol/L;

(3) After sealing the mixed solution of step (2), carry out the Mönstergold reaction under the assistance of magnetic stirring, the Mönstergold reaction temperature is 40°C, the reaction time is 24h, and the magneton speed is 1400rpm;

(4) Transfer the mixed solution after the reaction in step (3) to an evaporator for de-ethanol treatment, and evaporate for more than 24 hours. After the ethanol is completely evaporated, a transparent viscous DMAPPA liquid is obtained.

The preparation method of the novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate in this example is as follows: after the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the mass ratio of the powder to the liquid is Weigh the liquid at 1.0g/g, stir continuously with a magnet until uniform, mix the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

The hydrogen nuclear magnetic spectrum ( ^1HNMR ) of the new antibacterial bone cement made in this example and the pure PMMA bone cement without DMAPPA is shown in Figure 2. Compared with the hydrogen nuclear magnetic spectrum ( ^1HNMR ) of the pure PMMA bone cement, the new antibacterial bone cement The typical benzene ring signal appears at the position of 6.5-7.5ppm in cement, and the methyl signal at the N position appears at 3.7ppm. At the same time, the product belongs to the raw material dimethylaminoethyl methacrylate (DMAEMA) at 2-3ppm. The appearance of these signals indicated that the product DMAPPA successfully participated in the polymerization reaction of MMA, became a part of the main chain of PMMA, and could stably exist in bone cement.

Example 3

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate, raw materials include powder and liquid, the powder contains 82.10% polymethyl methacrylate (PMMA) microspheres, 2.90% of Initiator, 15.00% developer, liquid contains 94.62% methyl methacrylate (MMA), 0.40% catalyst, 4.98% dimethylaminotriclosan methacrylate (DMAPPA) by mass percentage.

The polymethyl methacrylate (PMMA) microspheres used in this example have a weight-average molecular weight _Mw in the range of 50000-120000, a number-average molecular weight _Mn in the range of 25000-96000, and a microsphere size in the range of 7-38 μm.

The initiator selected in this embodiment is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is barium sulfate (BaSO ₄ ).

Dimethylaminotriclosan methacrylate (DMAPPA) in the present embodiment is synthesized by the Menster Gold method, and its main preparation steps are as follows:

(1) Weigh two raw materials of dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan) in a molar ratio of 1:1;

(2) Add the two raw materials weighed in step (1) to ethanol, and prepare a mixed solution at a concentration of 3.3mol/L;

(3) After sealing the mixed solution of step (2), carry out the Mönstergold reaction under the assistance of magnetic stirring, the Mönstergold reaction temperature is 55°C, the reaction time is 20h, and the magneton speed is 1000rpm;

(4) Transfer the mixed solution after the reaction in step (3) to an evaporator for de-ethanol treatment, and evaporate for more than 24 hours. After the ethanol is completely evaporated, a transparent viscous DMAPPA liquid is obtained.

The preparation method of the novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate in this example is as follows: after the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the mass ratio of the powder to the liquid is Weigh the liquid at 2.5g/g, stir continuously with a magnet until uniform, mix the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

This embodiment synthesizes dimethylaminotriclosan methacrylate (DMAPPA), and uses the disk diffusion method to measure the diameter of the antibacterial ring it produces, and then evaluates its antibacterial ability. During the test, the concentration of the bacterial suspension is 1.5× Staphylococcus aureus, Escherichia coli and Escherichia coli with 10 ⁸ CFU/mL are the three target strains, and they are respectively coated on the entire MH agar plate, dipped in DMAPPA with a φ6mm×1mm drug-sensitive sheet, and then pasted on the MH agar plate covered with bacteria. On the agar plate, place the MH agar plate in a 37°C thermostat for 24 hours, take it out and take an optical photo. The optical photo of the antibacterial zone is shown in Figure 3. It can be seen from Figure 3 that the drug-sensitive sheet dipped with DMAPPA, its There was no growth of the above three kinds of target bacteria in the surrounding area, and an obvious bacteriostatic zone appeared. Then the bacteriostatic zone was measured and counted with the center of the drug-sensitive tablet as the origin, and the bacteriostatic zone produced by Staphylococcus aureus, E. The diameters were 37.27±0.23mm, 33.13±0.57mm, and 29.34±0.45mm, respectively, which were significantly higher than the lower limit of 6mm diameters that could be judged to have antibacterial properties, indicating that DMAPPA was effective against Gram-negative and positive representative strains and fungi. It showed obvious broad-spectrum antibacterial ability, and the antibacterial effect on three strains was as follows: Staphylococcus aureus > Escherichia coli > Candida albicans.

Example 4

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate, raw materials include powder and liquid, the powder contains 83.90% polymethylmethacrylate (PMMA) microspheres, 2.60% of Initiator, 13.50% developer, liquid by mass percent, containing 1.60% catalyst and fixed amount, methyl methacrylate (MMA) content is 83.64% in the first product, dimethylaminotrichloromethacrylate Raw ester (DMAPPA) is 14.76%; the content of methyl methacrylate (MMA) in the second product is 73.80%, and the content of dimethylaminotriclosan methacrylate (DMAPPA) is 24.60%; The content of methyl methacrylate (MMA) is 63.96%, and that of dimethylaminotriclosan methacrylate (DMAPPA) is 34.44%.

The polymethyl methacrylate (PMMA) microspheres used in this example have a weight-average molecular weight _Mw in the range of 50000-120000, a number-average molecular weight _Mn in the range of 25000-96000, and a microsphere size in the range of 7-38 μm.

The initiator used in this embodiment is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is zirconia (ZrO ₂ ).

Dimethylaminotriclosan methacrylate (DMAPPA) used in this embodiment is synthesized by the Munster Gold method, and its main preparation steps are as follows:

(1) Weigh two raw materials of dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan) in a molar ratio of 1:1;

(2) Add the two raw materials weighed in step (1) into ethanol, and prepare a mixed solution at a concentration of 3.2mol/L;

(3) After sealing the mixed solution in step (2), carry out the Mönstergold reaction under the assistance of magnetic stirring, the Mönstergold reaction temperature is 70°C, the reaction time is 6h, and the magneton speed is 1300rpm;

(4) Transfer the mixed solution after the reaction in step (3) to an evaporator for de-ethanol treatment, and evaporate for more than 24 hours. After the ethanol is completely evaporated, a transparent viscous DMAPPA liquid is obtained.

The preparation method of the novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate in this example is as follows: after the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the mass ratio of the powder to the liquid is Weigh the liquid at 2.0g/g, stir continuously with a magnet until uniform, mix the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

Change the addition amount of dimethylaminotriclosan methacrylate (DMAPPA) according to the mode of embodiment 4 to be 0% (that is, do not add DMAPPA, be pure PMMA bone cement), 14.76% (new antibacterial bone cement-1), 24.60% (new antibacterial bone cement-2), 34.44% (new antibacterial bone cement-3), adjust the addition of methyl methacrylate (MMA) at the same time, the amount of catalyst is unchanged, carry out the experiment, others are the same as above, Four kinds of bone cements were made, and the contact angle test was carried out with simulated human body fluid as the medium. For the specific test, the new antibacterial bone cement was cut into 15mm×10mm×1mm samples, and polished with 1200# sandpaper until the surface was smooth, and then Placed behind the sample stage; the simulated human body fluid (SBF) above it falls freely to the surface of the bone cement sample in the form of a droplet, and takes an optical photo of the droplet after it is stable; Measuring its size and judging its hydrophilicity, the photos of SBF droplets falling on the surface of three new antibacterial bone cements and the pure PMMA bone cement as a comparison are shown in Figure 4. It can be seen from Figure 4 that the SBF droplets on the bone cement The contact angles formed on the surface are all <90 ^° , showing hydrophilicity. The specific results and statistics obtained by the angle measurement method are shown in Table 1. It can be seen from Table 1 that the DMAPPA content is 14.76%, 24.60% and 34.44% respectively. The contact sizes of the three new antibacterial bone cements were 69.3±0.6°, 68.6±2.1°, and 57.6±2.3° in turn. Compared with the pure PMMA bone cement, the addition of water-soluble DMAPPA can further reduce the contact angle of the bone cement, and with the With the increase of the added content, the contact angle of the new antibacterial bone cement was further reduced, and the hydrophilicity could continue to be improved.

Table 1

Example 5

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate. The raw materials include powder and liquid. There are 3 products in total. The powder contains 87.50% polymethyl methacrylate (PMMA) Ball, 2.50% initiator, 10.00% developer, liquid by mass percentage, containing 0.80% catalyst and fixed amount, methyl methacrylate (MMA) content in the first product is 91.26%, methacrylic acid Dimethylaminotriclosan (DMAPPA) is 7.94%; the content of methyl methacrylate (MMA) in the second product is 83.28%, and dimethylaminotriclosan (DMAPPA) is 15.92%; The content of methyl methacrylate (MMA) in the three products is 75.39%, and that of dimethylaminotriclosan methacrylate (DMAPPA) is 23.84%.

The polymethyl methacrylate (PMMA) microspheres used in this example have a weight-average molecular weight _Mw in the range of 50000-120000, a number-average molecular weight _Mn in the range of 25000-96000, and a microsphere size in the range of 7-38 μm.

The initiator selected in this embodiment is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is zirconia (ZrO ₂ ).

Dimethylaminotriclosan methacrylate (DMAPPA) in the present embodiment is synthesized by the Menster Gold method, and its main preparation steps are as follows:

(1) Weigh two raw materials of dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan) in a molar ratio of 1:1;

(2) Add the two raw materials weighed in step (1) to ethanol, and prepare a mixed solution at a concentration of 3.25mol/L;

(3) After sealing the mixed solution of step (2), carry out the Mönstergold reaction under the assistance of magnetic stirring, the Mönstergold reaction temperature is 65°C, the reaction time is 16h, and the magneton speed is 900rpm;

(4) Transfer the mixed solution after the reaction in step (3) to an evaporator for de-ethanol treatment, and evaporate for more than 24 hours. After the ethanol is completely evaporated, a transparent viscous DMAPPA liquid is obtained.

The preparation method of the novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate in this example is as follows: after the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the mass ratio of the powder to the liquid is Weigh the liquid at 2.0g/g, stir continuously with a magnet until uniform, mix the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

Change the addition amount of dimethylaminotriclosan methacrylate (DMAPPA) according to the mode of embodiment 5 to be 0% (that is, do not add DMAPPA, be pure PMMA bone cement), 7.94% (new antibacterial bone cement-1), 15.92% (new antibacterial bone cement-2), 23.84% (new antibacterial bone cement-3), while adjusting the addition of methyl methacrylate (MMA), the amount of catalyst is unchanged, and the experiment is carried out. Others are the same as above, Make 4 kinds of bone cement, test its compressive strength, flexural strength and flexural elastic modulus according to the provisions of the international standard ISO5833:2002 (E) text and appendix A to F, during the compressive test, during the compressive test, The size of the sample is φ6mm×12mm, and the displacement speed of the cross head is 20mm/min. The 2% offset strength or the upper yield point strength that appears first on the strain-stress curve is taken as its compressive strength. During the bending test, use Four-point bending measurement method, the size of the sample is 75mm×10mm×3.3mm, the displacement speed of the cross head is set at 5mm/min, and the strength of the sample when it breaks is taken as its bending strength. The antibacterial bone cement of this series is The compressive stress-strain curves and flexural stress-strain curves are shown in Figure 5(a) and (b), respectively. It can be seen from Figure 5(a) that the three new antibacterial bone cements made with different DMAPPA contents have a corresponding The linear zone (double arrow range) and the strain at the breaking point on the compressive stress-strain curve of the antimicrobial bone cement are basically unchanged, but there are certain differences in the stress at the breaking point. It can be seen from Figure 5(b) that different new antibacterial bone cements have different flexural stress-strain There are large differences in the linear region of the curve (the range of double arrows), the strain at the breaking point and the stress. The mechanical properties summarized from the compressive and flexural stress-strain curves in Figure 5 are shown in Table 2. It can be seen from Table 2 that 3 The ranges of compressive strength, flexural strength and flexural modulus of this new type of antibacterial bone cement are 107.7±3.6MPa～125.7±3.6MPa, 87.8±7.4MPa～106.0±3.6MPa and 2.2±0.1GPa～2.8± 0.1GPa, higher than the average compressive strength ≥ 70MPa, average flexural strength ≥ 50MPa, and average flexural modulus ≥ 1.8GPa, the lower limit specified in ISO5833, showing good clinical application feasibility, compared with that without DMAPPA Compared with pure PMMA bone cement, the above mechanical properties are better, indicating that after the unsaturated C=C double bond participates in MMA polymerization, adding DMAPPA can further improve the mechanical properties of PMMA bone cement, and it is within the relative content range listed in this example , the mechanical properties of the new antibacterial bone cement did not deteriorate significantly with the increase of DMAPPA content.

Table 2

Example 6

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate, raw materials include powder, liquid, powder contains 89.10% polymethylmethacrylate (PMMA) microspheres, 2.90% of Initiator, 8.00% developer, liquid by mass percentage, containing 1.20% catalyst and fixed amount, methyl methacrylate (MMA) content is 89.91% in the first product, dimethylaminotrichloromethacrylate Raw ester (DMAPPA) is 8.89%; the content of methyl methacrylate (MMA) in the second product is 82.00%, and dimethylaminotriclosan methacrylate (DMAPPA) is 16.80%.

The polymethyl methacrylate (PMMA) microspheres used in this example have a weight-average molecular weight _Mw in the range of 50000-120000, a number-average molecular weight _Mn in the range of 25000-96000, and a microsphere size in the range of 7-38 μm.

The initiator selected in this embodiment is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is barium sulfate (BaSO ₄ ).

Dimethylaminotriclosan methacrylate (DMAPPA) in the present embodiment is synthesized by the Menster Gold method, and its main preparation steps are as follows:

(1) Weigh two raw materials of dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan) in a molar ratio of 1:1;

(2) Add the two raw materials weighed in step (1) to ethanol, and prepare a mixed solution at a concentration of 3.4mol/L;

(3) After sealing the mixed solution in step (2), carry out the Mönstergold reaction under the assistance of magnetic stirring, the Mönstergold reaction temperature is 60°C, the reaction time is 20h, and the magneton speed is 1100rpm;

(4) Transfer the mixed solution after the reaction in step (3) to an evaporator for de-ethanol treatment, and evaporate for more than 24 hours. After the ethanol is completely evaporated, a transparent viscous DMAPPA liquid is obtained.

The preparation method of the novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate in this example is as follows: after the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the mass ratio of the powder to the liquid is Weigh the liquid at 2.2g/g, stir continuously with a magnet until uniform, mix the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

Change the addition amount of dimethylaminotriclosan methacrylate (DMAPPA) according to the mode of embodiment 5 to be 0% (that is, do not add DMAPPA, be pure PMMA bone cement), 8.89% (new antibacterial bone cement-1), 16.80% (new antibacterial bone cement-2), while adjusting the amount of methyl methacrylate (MMA), the amount of catalyst was unchanged, and the experiment was carried out. Others were the same as above, and three kinds of bone cement were made according to the international standard ISO5833 : 2002 (E) text and appendixes A to F to test its curing performance; specifically, the non-sticky dough of the new antibacterial bone cement is embedded in a φ60mm×5mm disc mold, and the bottom circular section is touched with a temperature-measuring thermal probe , the other end of the probe is connected to a thermal recorder; start recording data when the powder and liquid are mixed, until the dough is completely solidified and gradually cooled down, then use the recorded data to draw a time-temperature curve, the results are shown in Figure 6, according to the curve in Figure 6 , select the highest exothermic peak as the highest exothermic temperature of bone cement, and the curing time as the corresponding value of curing temperature on the time-temperature curve. The curing properties of bone cement are further summarized in Table 3. The curing time of the bone cement falls within the range of 3min to 15min, and the maximum exothermic temperature is less than or equal to 90±5°C, which meets the curing performance requirements of the bone cement specified in ISO5833 when it is used as a dough, showing the feasibility of clinical application. Compared with PMMA bone cement, the maximum exothermic temperature of the new antibacterial bone cement added with DMAPPA further decreased, which is beneficial to reduce the heat damage of bone tissue and the subsequent aseptic loosening of the prosthesis caused by curing exotherm, and with the increase of the relative content of DMAPPA increase, the maximum exothermic temperature further decreases, which also shows that when DMAPPA participates in the polymerization reaction, its exothermic heat is smaller than that of MMA, and partial substitution can further reduce the exothermic temperature rise.

table 3

Example 7

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate, raw materials include powder, liquid, powder contains 84.90% polymethylmethacrylate (PMMA) microspheres, 1.40% of Initiator, 13.70% developer, liquid contains 75.88% methyl methacrylate (MMA), 0.68% catalyst and 23.44% dimethylaminotriclosan methacrylate (DMAPPA) by mass percentage.

The polymethyl methacrylate (PMMA) microspheres used in this example have a weight-average molecular weight _Mw in the range of 50000-120000, a number-average molecular weight _Mn in the range of 25000-96000, and a microsphere size in the range of 7-38 μm.

The initiator selected in this embodiment is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is barium sulfate (BaSO ₄ ).

Dimethylaminotriclosan methacrylate (DMAPPA) in the present embodiment is synthesized by the Menster Gold method, and its main preparation steps are as follows:

(1) Weigh two raw materials of dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan) in a molar ratio of 1:1;

(2) The two raw materials weighed in step (1) are added to ethanol, and a mixed solution is prepared at a concentration of 3.35mol/L;

(3) After sealing the mixed solution of step (2), carry out the Mönstergold reaction under the assistance of magnetic stirring, the Mönstergold reaction temperature is 68°C, the reaction time is 10h, and the magneton speed is 1300rpm;

(4) Transfer the mixed solution after the reaction of step (3) to an evaporator for de-ethanol treatment, and evaporate for more than 24 hours to obtain a transparent viscous DMAPPA liquid after the ethanol is completely evaporated;

The preparation method of the novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate in this example is as follows: after the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the mass ratio of the powder to the liquid is Weigh the liquid at 1.8g/g, stir continuously with a magnet until uniform, mix the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

In this example, a new type of antibacterial bone cement was made, and the diameter of the antibacterial ring produced by it was measured by the disc diffusion method, so as to evaluate its antibacterial ability. During the test, the golden yellow bone cement with a bacterial suspension concentration of 1.5×10 ⁸ CFU/mL was used for the test. Staphylococcus, Escherichia coli and Candida albicans are the three target strains, and they are respectively coated on the entire MH agar plate, and the new antibacterial bone cement is cut into 10mm×10mm×1mm samples, and then pasted on the MH agar plate coated with bacteria , place the MH agar plate in a 37°C incubator for 24 hours, take it out and take an optical photo. The optical photo of the inhibition zone is shown in Figure 6. On the plate, there was no growth of the above-mentioned target bacteria around the 6 samples of the new antibacterial bone cement, and a relatively obvious antibacterial ring appeared; while for Candida albicans, there was no obvious growth around the antibacterial bone cement on the agar plate. However, after uncovering the sample, it was found that there was no bacterial growth in the square area in direct contact with Candida albicans, which can also explain the antibacterial effect of antibacterial bone cement on Candida albicans. The antibacterial rings were measured and counted with the center of the bone cement sample as the origin, and the diameters of the antibacterial rings for Staphylococcus aureus, Escherichia coli and Candida albicans were 35.85±3.82mm, 25.39±3.07mm and 11.88±0.74mm, respectively. Exceeding the side length of the sample, that is, the new antibacterial bone cement has obvious broad-spectrum antibacterial ability on Gram-negative and positive representative strains and fungi, and the antibacterial effect on three kinds of bacteria is as follows: Staphylococcus aureus > Escherichia coli > Candida albicans, which is basically consistent with the results of the DMAPPA monomer inhibition zone test.

Example 8

An antibacterial bone cement modified by dimethylaminotriclosan methacrylate, raw materials include powder, liquid, powder contains 85.72% polymethylmethacrylate (PMMA) microspheres, 1.83% of Initiator, 12.45% developer, liquid by mass percentage, containing 1.00% catalyst and fixed amount, methyl methacrylate (MMA) content is 79.16% in the first product, dimethylaminotrichloromethacrylate Raw ester (DMAPPA) is 19.84%; the content of methyl methacrylate (MMA) in the second product is 69.24%, and the content of dimethylaminotriclosan methacrylate (DMAPPA) is 29.76%; The content of methyl methacrylate (MMA) is 59.32%, and that of dimethylaminotriclosan methacrylate (DMAPPA) is 39.68%.

The polymethyl methacrylate (PMMA) microspheres used in this example have a weight-average molecular weight _Mw in the range of 50000-120000, a number-average molecular weight _Mn in the range of 25000-96000, and a microsphere size in the range of 7-38 μm.

The initiator selected in this embodiment is benzoyl peroxide (BPO), the catalyst is N,N-dimethyl-p-toluidine (DmpT), and the developer is zirconium oxide (ZrO ₂ ).

Dimethylaminotriclosan methacrylate (DMAPPA) in the present embodiment is synthesized by the Menster Gold method, and its main preparation steps are as follows:

(1) Weigh two raw materials of dimethylaminoethyl methacrylate (DMAEMA) and triclosan (Triclosan) in a molar ratio of 1:1;

(2) Add the two raw materials weighed in step (1) to ethanol, and prepare a mixed solution at a concentration of 3.5mol/L;

(3) After sealing the mixed solution in step (2), carry out the Mönstergold reaction under the assistance of magnetic stirring, the Mönstergold reaction temperature is 45°C, the reaction time is 22h, and the magneton speed is 1200rpm;

(4) Transfer the mixed solution after the reaction in step (3) to an evaporator for de-ethanol treatment, and evaporate for more than 24 hours. After the ethanol is completely evaporated, a transparent viscous DMAPPA liquid is obtained.

The preparation method of the novel antibacterial bone cement modified by dimethylaminotriclosan methacrylate in this example is as follows: after the powder is weighed according to the proportion of the raw materials, it is continuously stirred with a spatula until it is uniform; the mass ratio of the powder to the liquid is Weigh the liquid at 2.0g/g, stir continuously with a magnet until uniform, mix the powder and liquid, stir, let stand, shape, and solidify to obtain a new type of antibacterial bone cement.

Change the add-on of dimethylaminotriclosan methacrylate (DMAPPA) according to the mode of embodiment 8 to be 19.84% (i.e. do not add), 39.68%, and adjust the add-on of methyl methacrylate (MMA) simultaneously, The amount of the catalyst was not changed, and the experiment was carried out. Others were the same as in Example 8, and three kinds of new antibacterial bone cements were made. The new antibacterial bone cements made in this example were shaped into cylinders of φ6mm×4mm, and then soaked in the mass fraction 75% ethanol solution and phosphate buffered saline (PBS) each for 12 hours, according to the ratio of surface area to medium volume 3.4cm ² /mL, put it into 0.43mL complete medium for MC3T3-E1 cell culture (containing 89% DMEM, 10% fetal bovine serum, and 1% penicillin/streptomycin dual antibiotics), then stood at 37°C for 24h and passed through 0.2μm sterile filtration to make bone cement extract, and the second generation MC3T3- E1 cells were added to each well of a 96-well plate containing 100 μL of complete medium at a cell density of 1×10 ⁵ cells/cm ² , cultured at 37°C for 24 h in a humidified atmosphere containing 5% CO ₂ , and then treated with an equal amount of The bone cement extract was replaced with the complete medium, and cultured in the same environment for 24 hours, and the relative proliferation rate (RGR) of the cells in the new antibacterial bone cement extract was detected according to the method stipulated in the national standard GB/T16886.12-2005 , and according to the ISO10993 standard to judge the corresponding toxicity level, the cytotoxicity test results are shown in Figure 8. From Figure 8, it can be seen that the new antibacterial bone cement, MC3T3-E1, with 19.84%, 29.76%, and 39.68% of DMAPPA The cell viability of the cells and their extracts co-cultured for 24 hours was 92.9%±0.5%, 87.3%±1.7% and 93.6%±0.03%, respectively; the cell viability after the co-culture time was extended to 72h was 90.7%±5.2%, 85.3% % ± 3.2% and 74.2% ± 4.5%, according to ISO10993, the cell viability of the three kinds of antibacterial bone cement is greater than 70%, the toxicity reaction grade is 0 or 1, it is judged as no cytotoxicity, showing good in vitro biological phase Capacitance.

Claims (8)

1. The dimethylamino triclosan methacrylate modified antibacterial bone cement is characterized by comprising the following raw materials in percentage by mass: 82.10 to 94.30 percent of polymethyl methacrylate microsphere, 0.70 to 2.90 percent of initiator and 5.00 to 15.00 percent of developer, wherein the liquid comprises the following components in percentage by mass: 58.32 to 94.62 percent of methyl methacrylate, 0.40 to 2.00 percent of catalyst and 4.98 to 39.68 percent of dimethylamino triclosan methacrylate.

2. The antibacterial bone cement modified by dimethylamino triclosan methacrylate according to claim 1, wherein the mass ratio of powder to liquid in the raw material is 1.0-3.0 g/g.

3. The dimethylaminotriclosan methacrylate-modified antibacterial bone cement according to claim 1, wherein the polymethyl methacrylate microspheres have a weight average molecular weight M _w 50000-120000 and number average molecular weight M _n 25000-96000, and the microsphere size is 7-38 μm.

4. The antimicrobial cement modified with dimethylaminotriclosan methacrylate according to claim 1, wherein the initiator is benzoyl peroxide, the catalyst is N, N-dimethyl-p-toluidine, and the developer is one of zirconia or barium sulfate.

5. The antimicrobial cement modified with dimethylaminotriclosan methacrylate according to claim 1, wherein the preparation steps of the dimethylaminotriclosan methacrylate are as follows:

(1) Weighing dimethylaminoethyl methacrylate and triclosan;

(2) Adding the two materials weighed in the step (1) into absolute ethyl alcohol to prepare a mixed solution;

(3) Sealing the mixed solution obtained in the step (2), and carrying out a Gastrodia reaction under the assistance of magnetic stirring;

(4) And (3) carrying out ethanol removal treatment on the mixed solution after the reaction in the step (3) to obtain the dimethylaminotriclosan methacrylate.

6. The dimethylaminotriclosan methacrylate-modified antibacterial bone cement of claim 5, wherein the molar ratio of dimethylaminoethyl methacrylate to triclosan of step (1) is 1:1.

7. The dimethylaminotriclosan methacrylate-modified antibacterial bone cement according to claim 5, wherein the concentration of the mixed solution of step (2) is 3.2 to 3.5mol/L.

8. The antibacterial bone cement modified by dimethylamino triclosan methacrylate according to claim 5, wherein the reaction temperature of the gatepost in the step (3) is 40-70 ℃, the reaction time is 4-24 hours, and the magnetic stirring magnet rotating speed is 800-1400 rpm.

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