阅读说明：本技术 智能化控释载药骨水泥及其制备方法和应用 (Intelligent controlled-release medicine-carrying bone cement and preparation method and application thereof ) 是由 聂洪涛 张凯 张洪玮 于 2020-08-07 设计创作，主要内容包括：本发明提供了一种智能化控释载药骨水泥及其制备方法和应用,涉及生物医用材料技术领域,智能化控释载药骨水泥包括粉剂和液剂；粉剂和液剂的液固比为1ml：2-2.2g。粉剂包括质量百分比的如下组分：聚甲基丙烯酸甲酯79.5±1.0％、引发剂0.5±0.1％、空心聚多巴胺纳米粒子/抗生素载药微球10.0±1.0％、显影剂10.0±1.0％。本发明解决目前含抗骨水泥产品药物释放不可控、突释、微球类载体包埋药物率不高的问题,通过加入空心聚多巴胺纳米粒子/抗生素载药微球不仅载药量高且稳定,防止药物过早释放,且该微球本身具有pH响应性,能够根据pH变化控释药物,此外,对骨水泥生物活性起到促进作用。(The invention provides an intelligent control drug-loaded bone cement, a preparation method and application thereof, relating to the technical field of biomedical materials, wherein the intelligent control drug-loaded bone cement comprises powder and liquid; the liquid-solid ratio of the powder and the liquid is 1ml: 2-2.2 g. The powder comprises the following components in percentage by mass: 79.5 +/-1.0 percent of polymethyl methacrylate, 0.5 +/-0.1 percent of initiator, 10.0 +/-1.0 percent of hollow polydopamine nano particle/antibiotic drug-loaded microsphere and 10.0 +/-1.0 percent of developer. The invention solves the problems of uncontrollable drug release, burst release and low drug embedding rate of microsphere carriers of the existing bone cement-resistant products, the hollow polydopamine nanoparticle/antibiotic drug-loaded microsphere is added, so that the drug loading is high and stable, the premature release of the drug is prevented, the microsphere has pH responsiveness, the drug can be controlled and released according to the pH change, and in addition, the promotion effect on the bioactivity of the bone cement is realized.)

1. An intelligent control drug-loaded bone cement is characterized by comprising powder and liquid; the liquid-solid ratio of the powder and the liquid is 1ml: 2-2.2 g;

the powder comprises the following components in percentage by mass:

2. the intelligent control release drug-loaded bone cement of claim 1, wherein the loading of the antibiotic in the hollow polydopamine nanoparticle/antibiotic drug-loaded microsphere is 23-30%.

3. The intelligent control release drug-loaded bone cement according to claim 2, wherein the antibiotic comprises one or more of gentamicin, vancomycin, tobramycin or clindamycin, preferably gentamicin, vancomycin or tobramycin.

4. The intelligent release drug-loaded bone cement as claimed in claim 1, wherein the particle size of the hollow poly-dopamine nanoparticles is 100-300 nm.

5. The intelligent controlled release drug-loaded bone cement according to claim 1, wherein the liquid formulation comprises the following components in mass concentration:

98 plus or minus 1 percent of methyl methacrylate monomer;

2 plus or minus 0.5 percent of accelerant;

70. + -.10 ppm of inhibitor.

6. The intelligent controlled release drug-loaded bone cement according to any one of claims 1 to 5, wherein the initiator is benzoyl peroxide;

preferably, the developer is barium sulfate and/or zirconium dioxide;

preferably, the accelerator is N, N-dimethyl-p-toluidine;

preferably, the polymerization inhibitor is hydroquinone.

7. The method for preparing the intelligent controlled release drug-loaded bone cement of any one of claims 1 to 6, which comprises the following steps:

(a) preparing hollow polydopamine nano-particles/antibiotic drug-loaded microspheres;

(b) mixing polymethyl methacrylate, an initiator, hollow polydopamine nano particles/antibiotic drug-loaded microspheres and a developing agent according to a ratio to obtain powder;

(c) the powder and the liquid form the intelligent control medicine-carrying bone cement.

8. The method of claim 7, wherein step (a) comprises the steps of:

dissolving the hollow polydopamine nanoparticles in a buffer solution containing antibiotics for light-resistant reaction, and washing after separation to obtain hollow polydopamine nanoparticles/antibiotic drug-loaded microspheres;

preferably, the antibiotic concentration in the buffer containing the antibiotic is 0.1-0.3 mg/ml.

9. The method for preparing the hollow polydopamine nanoparticles according to claim 8, wherein the method for preparing the hollow polydopamine nanoparticles comprises the following steps:

with SiO₂The microsphere is used as a template, dopamine is oxidized and polymerized on the surface of the microsphere to form a shell layer under the alkaline condition, and the hollow polydopamine nano particle is obtained after the template is removed;

preferably, the preparation method of the hollow polydopamine nanoparticles comprises the following steps:

synthesis of SiO by stober method₂Nanoparticles of SiO₂Dispersing the nano particles in water to obtain a dispersion liquid A; dispersing dopamine hydrochloride in the dispersion liquid A, adding an alkali solution, changing the mixed liquid into black, separating after mixing reaction, washing and drying a product;

dispersing the dried product in water, adding hydrofluoric acid, mixing, reacting, separating, washing, and drying to obtain hollow poly-dopamine nanoparticles.

10. Use of an intelligently controlled release drug-loaded bone cement according to any one of claims 1 to 6 in a bone repair material;

preferably, the powder and the liquid are blended in proportion to obtain the bone cement to be used.

Technical Field

The invention relates to the technical field of biomedical materials, in particular to an intelligent controlled release medicine-carrying bone cement and a preparation method and application thereof.

Background

PMMA bone cement (polymethylmethacrylate), which is a typical representative of bio-organic polymer bone cement material, has the characteristics of filling the gap between bone and prosthesis and having spontaneous coagulation due to polymerization reaction, and is mainly used for artificial joint replacement surgery. The bone cement is doped with antibiotics, so that a high-concentration antibiotic environment is locally formed at an implantation position, and the postoperative infection can be reduced or the postoperative infection of the artificial joint replacement can be treated.

The PMMA bone cement loaded with antibiotics at present has the following defects:

1. the drug release is not complete enough, and the internal antibiotics can not be well released, thereby causing waste.

2. Drug release cannot be controlled as desired.

3. The phenomenon of 'sudden release' exists: after being implanted, the existing commercial bone cement containing the antibiotic can generate the phenomenon of antibiotic 'burst release' in the early stage of implantation, so that a local antibiotic high-concentration environment can be formed in the early stage of implantation. But not all inflammation or infection occurs early in implantation. For infection or inflammation generated after a period of time after implantation, the initial release of a large amount of antibiotics causes the waste of antibiotics, so that the timely treatment effect cannot be achieved, and serious patients may face the risk of secondary renovation.

In addition, the biological activity of PMMA bone cement loaded with antibiotics at present needs to be further improved.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The invention aims to provide intelligent controlled-release bone cement carrying drugs, which can solve the problem that the drug release of the existing bone cement-resistant product is uncontrollable and improve the overall drug release rate and the biological activity of the bone cement.

The invention also aims to provide a preparation method of the intelligent controlled release medicine-carrying bone cement.

The invention also aims to provide application of the intelligent controlled release medicine-carrying bone cement.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

in a first aspect, the invention provides an intelligent controlled release drug-loaded bone cement, which comprises powder and liquid; the liquid-solid ratio of the powder and the liquid is 1(ml) to 2-2.2 (g);

the powder comprises the following components in percentage by mass:

furthermore, the loading capacity of the antibiotic in the hollow polydopamine nanoparticle/antibiotic drug-loaded microsphere is 23-30%.

Further, the antibiotic comprises one or more of gentamicin, vancomycin, tobramycin or clindamycin, and is preferably gentamicin, vancomycin and tobramycin.

Further, the particle size of the hollow polydopamine nanoparticle is 100-300 nm.

Further, the liquid agent comprises the following components in mass concentration:

98 plus or minus 1 percent of methyl methacrylate monomer;

2 plus or minus 0.5 percent of accelerant;

70. + -.10 ppm of inhibitor.

Further, the initiator is benzoyl peroxide;

preferably, the developer is barium sulfate and/or zirconium dioxide;

preferably, the accelerator is N, N-dimethyl-p-toluidine;

preferably, the polymerization inhibitor is hydroquinone.

In a second aspect, the invention provides a preparation method of the intelligent controlled release drug-loaded bone cement, which comprises the following steps:

(a) preparing hollow polydopamine nano-particles/antibiotic drug-loaded microspheres;

(b) mixing polymethyl methacrylate, an initiator, hollow polydopamine nano particles/antibiotic drug-loaded microspheres and a developing agent according to a ratio to obtain powder;

(c) the powder and the liquid form the intelligent control medicine-carrying bone cement.

Further, the step (a) comprises the steps of:

dissolving the hollow polydopamine nanoparticles in a buffer solution containing antibiotics for light-resistant reaction, and washing after separation to obtain hollow polydopamine nanoparticles/antibiotic drug-loaded microspheres;

preferably, the antibiotic concentration in the buffer containing the antibiotic is 0.1-0.3 mg/ml.

Further, the preparation method of the hollow polydopamine nanoparticles comprises the following steps:

with SiO₂The microsphere is used as a template, dopamine is oxidized and polymerized on the surface of the microsphere to form a shell layer under the alkaline condition, and the hollow polydopamine nano particle is obtained after the template is removed;

preferably, the preparation method of the hollow polydopamine nanoparticles comprises the following steps:

synthesis of SiO by stober method₂Nanoparticles of SiO₂Dispersing the nano particles in water to obtain a dispersion liquid A; dispersing dopamine hydrochloride in the dispersion liquid A, adding an alkali solution, changing the mixed liquid into black, separating after mixing reaction, washing and drying a product;

dispersing the dried product in water, adding hydrofluoric acid, mixing, reacting, separating, washing, and drying to obtain hollow poly-dopamine nanoparticles.

In a third aspect, the invention provides an application of the intelligent control drug-loaded bone cement in a bone repair material;

preferably, the powder and the liquid are blended in proportion to obtain the bone cement to be used.

The intelligent control drug-loaded bone cement provided by the invention and the preparation method and the application thereof have the following beneficial effects:

1. the hollow polydopamine nano-particle/antibiotic drug-loaded microsphere is added into the bone cement, the polydopamine microsphere has pH sensitivity (pH response), the structure is not changed under the normal environment (pH7.4) of a human body, the structure is unstable under the acidic environment (such as local pH of an infection position is approximately equal to 5.0), the polydopamine microsphere is easy to degrade, the drug embedded in the polydopamine microsphere is released, and the drug is controlled and released according to the change of the pH, so that the drug release is realized according to the requirement.

2. The drug loading mode of the invention comprises physical embedding of the hollow polydopamine microspheres and chemical combination of polydopamine and antibiotics (the catechol group on the polydopamine and the primary amino group of the antibiotics are easy to have Schiff base reaction and are combined with the polydopamine in the form of chemical bonds), so that the polydopamine as a carrier has high and stable drug loading.

3. The hollow polydopamine microspheres embed the drugs and are combined with the drugs on the surfaces of the microspheres by chemical bonds, so that the hollow polydopamine microspheres are relatively stable, the premature release of the drugs can be prevented, and the effective utilization of the drugs is ensured.

4. By controlling the proportion of the added hollow polydopamine nano particles/antibiotic drug-loaded microspheres in the powder, the mechanical property of the bone cement is not influenced, and the biological activity of the bone cement is improved.

5. The preparation method is simple and easy to implement, needs few raw materials and has few reaction steps.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a graph showing comparative results of drug release tests under different pH environments provided by the examples of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention is provided for preventing the burst release of the drug of PMMA bone cement carrying antibiotics, obtaining the performance of the controlled release drug, solving the problem of low drug embedding rate of the microsphere carrier and further improving the biological activity of the bone cement.

According to a first aspect of the invention, the invention provides an intelligent control drug-loaded bone cement, which comprises powder and liquid; the liquid-solid ratio of the powder and the liquid is 1(ml) to 2-2.2 (g);

the powder comprises the following components in percentage by mass:

the PMMA bone cement comprises powder and liquid, wherein the liquid-solid ratio of the powder to the liquid is 1ml: 2-2.2g, such as 1ml:2g, 1ml:2.1g and 1ml:2.2 g.

Typical, but not limiting, amounts of polymethyl methacrylate (PMMA) are, for example, 78.5%, 79%, 80%, 80.5%, based on the powder (100%). Typical but non-limiting amounts of initiator are for example 0.4%, 0.5% or 0.6%. Typical but non-limiting contents of hollow polydopamine nanoparticles/antibiotic drug-loaded microspheres are for example 9%, 9.5%, 10.5%, 11%. Typical but non-limiting levels of developer are, for example, 9%, 9.5%, 10.5%, 11%.

[ initiator ]

Initiators include, but are not limited to, Benzoyl Peroxide (BPO).

When the initiator is used for mixing the powder and the liquid, the polymerization reaction of the polymethyl methacrylate and the methyl methacrylate monomer is initiated until the polymethyl methacrylate and the methyl methacrylate monomer are solidified.

[ hollow poly dopamine nanoparticle/antibiotic drug-loaded microsphere ]

The "/" in the hollow polydopamine nanoparticle/antibiotic drug-loaded microsphere means "and", and means that the antibiotic is embedded in the hollow polydopamine nanoparticle (microsphere) to form the drug-loaded microsphere.

The microsphere embedded antibiotics are suitable for mainstream antibiotics, such as gentamicin, vancomycin, tobramycin and the like which are applied to bone cement in the market.

The hollow poly-dopamine nano-particles are not limited, can be obtained commercially or can be prepared by self.

In one embodiment, the hollow polydopamine nanoparticles are prepared by:

taking 100mg of SiO₂Dispersing the nano particles in 30-50mL of deionized water, weighing 100-150mg of dopamine hydrochloride, dispersing the dopamine hydrochloride in the solution, adding 200-300 mu L of NaOH (1M) solution, reacting for 10-12h at room temperature by magnetic stirring, performing centrifugal separation, washing the product with deionized water for three times, and performing freeze drying.

And finally, dispersing the dried product in 30-50mL of deionized water, measuring 500 mu L of hydrofluoric acid, fully mixing and reacting for 2-4h, centrifuging and washing for three times, and freeze-drying to obtain the hollow polydopamine nano-particles.

Wherein SiO is₂The nanoparticles can be synthesized by known methods, for example, by the stober method.

In this way, SiO is used₂The microspheres are used as templates, dopamine is oxidized and polymerized on the surfaces of the microspheres to form shell layers under alkaline conditions, and the hollow poly-dopamine nanoparticles are obtained after the templates are removed.

In a preferred embodiment, the particle size of the hollow polydopamine nanoparticles is 100-300 nm.

The drug loading method of the microspheres is not limited.

In one embodiment, for example gentamicin, the antibiotic loading step is as follows:

weighing 5-15mg of gentamicin sulfate, dissolving in 50mL of ready-prepared PBS solution (pH7.4), preparing to obtain 0.1-0.3mg/mL solution, and storing in dark place;

weighing 3-6mg of hollow poly dopamine-based nanoparticles, dissolving in 5mL of the prepared solution, stirring for 6-12h in a dark place, centrifugally storing after reaction, centrifugally washing once by using PBS buffer solution, and removing unloaded antibiotics.

In a preferred embodiment, the loading of the antibiotic in the hollow polydopamine nanoparticle/antibiotic-loaded microsphere is 23-30%, such as 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30%.

The physical embedding and chemical combination of the hollow polydopamine nanoparticle microspheres are simultaneously used for drug loading, besides the physical embedding, the catechol group on the polydopamine and the primary amino group of the antibiotic are easy to have Schiff base reaction and are combined with the polydopamine in a chemical bond form, so that the polydopamine serving as a carrier has high and stable drug loading. The medicine is embedded in the polydopamine microspheres, and is chemically combined on the surfaces of the microspheres, so that the embedding is complete, the chemical combination is stable, the release is prevented from being too fast and too much, the premature release is prevented, and the effective utilization of the medicine is ensured. Therefore, the method can prevent the initial burst release of the drug and solve the problem of low drug embedding rate of the microsphere carrier.

The hollow polydopamine nano-particle/antibiotic drug-loaded microsphere has pH responsiveness, and intelligent controlled release is realized.

pH response principle:

when the bone joint and the surrounding soft tissues are infected, the blood supply of local tissues at the infected part is reduced due to vasoconstriction, so that the blood oxygen and nutrient deficiency is caused, the glycolysis is increased, and the surrounding lactic acid content is increased. Finally, the pH value of the local part of the infected part is reduced (the pH value can be approximately equal to 5.0), and the part is slightly acidic.

The structure of the polydopamine microsphere is unchanged under the normal environment (pH7.4) of a human body, and the structure of the polydopamine microsphere is unstable and easy to biodegrade under the acidic environment (such as the local pH of an infection position is approximately equal to 5.0), so that the drug embedded in the microsphere and combined on the surface of the microsphere is released, and the purpose of controlled release is achieved.

The drug release in the bone cement has pH sensitivity, and the drug release rate is controlled according to the change of the pH value of the local environment, so as to achieve the release according to the requirement.

[ developer ]

Developers include, but are not limited to, barium sulfate or zirconium oxide.

The developer is used for facilitating observation in the operation.

Further, the liquid agent comprises the following components in mass concentration:

98 plus or minus 1 percent of methyl methacrylate monomer;

2 plus or minus 0.5 percent of accelerant;

70. + -.10 ppm of inhibitor.

Typical but non-limiting amounts of methyl methacrylate monomer are, for example, 97%, 97.5%, 98.5%, 99% based on the liquor. Typical but non-limiting amounts of accelerators are for example 1.5%, 2% or 2.5%. Typical but non-limiting amounts of polymerization inhibitors are for example 60ppm, 65ppm, 75ppm, 80 ppm.

Accelerators include, but are not limited to, N-dimethyl-p-toluidine. Used for promoting the bone cement polymerization process.

Polymerization inhibitors include, but are not limited to, hydroquinone. Used for preventing the self-polymerization of the methyl methacrylate in the liquid agent.

The invention solves the problems of controlled release and burst release of the PMMA bone cement carrying antibiotics at present, and improves the overall release rate of the medicine. Meanwhile, the biological activity of the bone cement is improved while the mechanical property of the bone cement is not influenced. The proportion of the polydopamine drug-loaded microspheres in the powder is controlled, and the balance between the mechanical property and the drug controlled release property is achieved.

According to a second aspect of the present invention, there is provided a method for preparing the above intelligent controlled release drug-loaded bone cement, comprising the steps of:

(a) preparing hollow polydopamine nano-particles/antibiotic drug-loaded microspheres;

(b) mixing polymethyl methacrylate, an initiator, hollow polydopamine nano particles/antibiotic drug-loaded microspheres and a developing agent according to a ratio to obtain powder;

(c) the powder and the liquid form the intelligent control medicine-carrying bone cement.

Further, the step (a) comprises the steps of:

dissolving the hollow polydopamine nanoparticles in a buffer solution containing antibiotics for light-resistant reaction, and washing after separation to obtain hollow polydopamine nanoparticles/antibiotic drug-loaded microspheres;

preferably, the antibiotic concentration in the buffer containing the antibiotic is 0.1-0.3%.

Taking gentamicin as an example, the method specifically comprises the following steps:

weighing 5-15mg of gentamicin sulfate, dissolving in 50mL of ready-prepared PBS solution (pH7.4), preparing to obtain 0.1-0.3mg/mL solution, and storing in dark place;

weighing 3-6mg of hollow poly dopamine-based nanoparticles, dissolving in 5mL of the prepared solution, stirring for 6-12h in a dark place, centrifugally storing after reaction, centrifugally washing once by using PBS buffer solution, and removing unloaded antibiotics.

Further, the preparation method of the hollow polydopamine nanoparticles comprises the following steps:

with SiO₂The method comprises the following steps of (1) taking the microsphere as a template, oxidizing and self-polymerizing dopamine on the surface of the microsphere to form a shell layer under an alkaline condition, and removing the template to obtain the hollow polydopamine nano-particle, wherein the method comprises the following steps:

synthesis of SiO by stober method₂Nanoparticles of SiO₂Dispersing the nano particles in water to obtain a dispersion liquid A; dispersing dopamine hydrochloride in the dispersion liquid A, adding an alkali solution, changing the mixed liquid into black, separating after mixing reaction, washing and drying a product;

dispersing the dried product in water, adding hydrofluoric acid, mixing, reacting, separating, washing, and drying to obtain hollow poly-dopamine nanoparticles.

The method specifically comprises the following steps: taking 100mg of SiO₂Dispersing the nano particles in 30-50mL of deionized water, weighing 100-150mg of dopamine hydrochloride, dispersing the dopamine hydrochloride in the solution, adding 200-300 mu L of NaOH (1M) solution, reacting for 10-12h at room temperature by magnetic stirring, performing centrifugal separation, washing the product with deionized water for three times, and performing freeze drying.

And finally, dispersing the dried product in 30-50mL of deionized water, measuring 500 mu L of hydrofluoric acid, fully mixing and reacting for 2-4h, centrifuging and washing for three times, and freeze-drying to obtain the hollow polydopamine nano-particles.

The polydopamine drug-carrying microsphere has mild preparation conditions, few required raw materials, few reaction steps and simple and easy whole preparation method.

According to a third aspect of the invention, the application of the intelligent control drug-loaded bone cement in a bone repair material is provided.

Preferably, the powder and the liquid are blended in proportion to obtain the bone cement to be used.

It should be noted that the method of using the bone cement herein refers to the mixing stage of powder and liquid before filling into human body, at which time the bone cement to be injected is in the shape of toothpaste or dough, and is not completely solidified for use. Thus, no treatment of the disease is contemplated.

The invention is further illustrated by the following examples. The materials in the examples are prepared according to known methods or are directly commercially available, unless otherwise specified.