Amphiphilic biodegradable bone repair material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of biomedical materials, and particularly relates to an amphiphilic biodegradable bone repair material which comprises a polycaprolactone-polyethylene glycol copolymer, an inorganic material, a growth factor and a buffer salt solution, wherein the polycaprolactone-polyethylene glycol copolymer is in a hydrophilic and hydrophobic balance state in the buffer salt solution; according to the amphipathic biodegradable bone repair material, the polycaprolactone-polyethylene glycol copolymer material easy to shape is selected to be matched with the growth factor and the inorganic matter material to form the bone repair material, and the growth factor can be adsorbed to the surface of the inorganic matter material to be slowly released; the polycaprolactone-polyethylene glycol copolymer and the inorganic material compounded with the growth factors form the bone defect filling material easy to shape, the bone defect filling material can be biologically degraded in a normal clinical use environment, and meanwhile, the situation that an existing product is affected by high temperature in the shaping aspect is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and in particular relates to an amphiphilic biodegradable bone repair material and a preparation method and application thereof. Background Art

[0002] Bone injury repair is one of the common problems in orthopedic clinics. With the increase of bone injuries caused by population aging and traffic accidents, there are more than 50 million cases of bone injury or bone defect in my country every year. For the repair of large-sized non-self-healing bone defects, doctors need to implant bone transplant materials for filling and repair. Therefore, research and development of new, safe and efficient bone defect repair materials are of great significance in clinical practice. At present, the commonly used bone defect repair methods include autologous bone transplantation, allogeneic bone transplantation and tissue engineering bone transplantation. Among them, autologous bone transplantation is considered to be the gold standard in clinical practice, but it is restricted by conditions such as limited bone volume and secondary trauma; the source of allogeneic bone transplantation is wider than that of autologous bone, but there are risks such as immune rejection, which are also subject to more restrictions; tissue engineering bone is a biomaterial prepared by means of tissue engineering, which has three elements, namely scaffold material, cytokine and cell. Commonly used products are composed of scaffold material or scaffold material / cytokine complex. The source of tissue engineering bone is polymer or inorganic matter, which has high safety. Therefore, the amphiphilic biodegradable bone repair material involved in this patent belongs to the field of tissue engineering.

[0003] In actual situations, since the causes of bone defects are mostly unpredictable, such as trauma, car accidents, tumor resection, etc., in clinical practice, most bone repair products are composed of metal materials, polyester materials, or hydroxyapatite inorganic materials. Some products will add some growth factors to accelerate the bone repair process at the defect site. Due to different causes of the disease, the shape of the bone defect is usually irregular, which requires the bone transplant material to have a plastic property, allowing doctors to shape it arbitrarily according to the shape of the bone defect during the operation. After the operation, the material can effectively induce new bone regeneration at the defect site and finally achieve bone defect healing. However, the plastic property has very high requirements for the material. Existing products are still mainly allogeneic bones and tissue process scaffolds, and no plastic products have been launched on the market.

[0004] For high molecular polymers, polymers that are completely soluble in water cannot achieve the shaping effect, while polymers that are completely insoluble in water cannot be mixed with buffer solutions, growth factors and other substances. Therefore, in order to achieve the shaping ability of high molecular polymers, it is necessary to regulate their hydrophilicity and hydrophobicity.

[0005] It should be noted that the above information disclosed in this background technology section is only used to understand the background technology of the present application concept, and therefore, the above description is not considered to constitute information of the prior art. Summary of the invention

[0006] The embodiments of the present disclosure at least provide an amphiphilic biodegradable bone repair material and a preparation method and application thereof, wherein the bone repair material is easy to shape.

[0007] In the first aspect, the embodiments of the present disclosure provide an amphiphilic biodegradable bone repair material, comprising: a polycaprolactone-polyethylene glycol copolymer, an inorganic material, a growth factor and a buffered salt solution. The polycaprolactone-polyethylene glycol copolymer is easy to shape and is in a hydrophilic-hydrophobic equilibrium state in the buffered salt solution. The growth factor is attached to the surface of the inorganic material to play a role in inducing bone regeneration.

[0008] In an optional embodiment, the molecular weight of the polycaprolactone-polyethylene glycol copolymer is 10,000-200,000; the mass proportion of the polycaprolactone-polyethylene glycol copolymer in the amphiphilic biodegradable bone repair material is 20-90%.

[0009] In an optional embodiment, the molar proportion of the repeating units of caprolactone in the polycaprolactone-polyethylene glycol copolymer is 30-60%.

[0010] In an optional embodiment, the polyethylene glycol in the polycaprolactone-polyethylene glycol copolymer includes any one of polyethylene glycol and polyethylene glycol monomethyl ether or a combination of both.

[0011] In an optional embodiment, the inorganic material includes any one or more combinations of hydroxyapatite, β-tricalcium phosphate, calcium carbonate and calcium silicate; the mass proportion of the inorganic material in the amphiphilic biodegradable bone repair material is 5-30%.

[0012] In an optional embodiment, the particle size of the inorganic material is in the range of 0.5-100 μm.

[0013] In an optional embodiment, the growth factor comprises any one of BMP-2 and BMP-7 bone morphogenetic proteins or a combination of both; the dosage of the growth factor is 0.1-1 mg / mL.

[0014] In an optional embodiment, the molding temperature of the polycaprolactone-polyethylene glycol copolymer is 4-50°C, preferably 20-40°C.

[0015] In a second aspect, the embodiments of the present disclosure also provide a method for preparing the amphiphilic biodegradable bone repair material as described above, comprising the following steps: step S1, pre-loading polycaprolactone-polyethylene glycol copolymer, inorganic material, growth factor and buffered salt solution into a container according to a proportion and mixing them evenly; step S2, directly filling or freeze-drying the evenly mixed components to obtain the amphiphilic biodegradable bone repair material.

[0016] In an optional embodiment, the packaging form filled in step S2 includes prefilled syringes and vials.

[0017] In a third aspect, the embodiments of the present disclosure also provide an application of the above-mentioned amphiphilic biodegradable bone repair material in the field of orthopedics.

[0018] The beneficial effect of the present invention is that the amphiphilic biodegradable bone repair material and its preparation method and application are formed by selecting a polycaprolactone-polyethylene glycol copolymer that can be shaped under normal clinical use conditions, in combination with growth factors and inorganic materials to form a bone repair material. The growth factor can be adsorbed on the inorganic material for sustained-release bone induction repair. The polycaprolactone-polyethylene glycol copolymer and the inorganic material compounded with the growth factor form an easily shaped bone defect filling material, which can be biodegraded under normal clinical use conditions, and also avoids the influence of high temperature on the shaping of existing products.

[0019] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A diagram of a pre-filled finished product of the bone repair material of Example 1 provided in the embodiments of the present disclosure;

[0023] Figure 2 The injection effect of the bone repair material of Example 1 provided in the embodiments of the present disclosure when used;

[0024] Figure 3 This is a morphological image of the appearance of polycaprolactone-polyethylene glycol powder in the bone repair material of Example 3 provided in the embodiments of the present disclosure;

[0025] Figure 4 This is a morphological diagram of the polycaprolactone-polyethylene glycol powder being molded into a mass shape in the bone repair material of Example 3 provided in the embodiments of the present disclosure;

[0026] Figure 5 This is a pie-shaped morphology diagram of polycaprolactone-polyethylene glycol powder in the bone repair material of Example 3 provided in the embodiments of the present disclosure;

[0027] Figure 6 This is a morphological diagram of polycaprolactone-polyethylene glycol powder molded into strips in the bone repair material of Example 3 provided in the embodiments of the present disclosure;

[0028] Figure 7 The cell compatibility test results of the bone repair material extracts of different concentrations in Example 6 provided in the embodiments of the present disclosure;

[0029] Figure 8 The results of in vitro osteogenic differentiation of the bone repair material, rhBMP-2 loaded bone repair material, negative control group and positive control group provided in Example 8 of the present disclosure. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are 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 are within the scope of protection of the present invention.

[0031] As used herein, the phrases "in one embodiment," "according to one embodiment," "in some embodiments," and the like generally refer to the fact that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure. Therefore, a particular feature, structure, or characteristic may be included in more than one embodiment of the present disclosure, so that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example," "exemplary," and the like are used to "serve as an example, instance, or illustration." Any implementation, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. On the contrary, the use of the terms "example," "exemplary," and the like is intended to present concepts in a concrete manner.

[0032] Herein, example embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as "at least one of..." modify the entire list of elements when following a list of elements, rather than modifying individual elements in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0033] The terms used herein are only used to describe specific exemplary configurations and are not intended to be limited. As used herein, the singular articles "one", "an" and "the" may also be intended to include plural forms, unless it is clearly indicated above that this is not the case. The terms "comprise", "include" and "have" are inclusive, and therefore specify the presence of features, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and / or combinations thereof. The method steps, processes and operations described herein should not be interpreted as necessarily requiring them to be performed in the specific order discussed or shown, unless specifically identified as an execution order. Additional or alternative steps may be adopted.

[0034] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0035] The disclosed embodiment provides an amphiphilic biodegradable bone repair material, comprising: a polycaprolactone-polyethylene glycol copolymer, an inorganic material, a growth factor and a buffered salt solution; wherein the polycaprolactone-polyethylene glycol copolymer is in a hydrophilic-hydrophobic equilibrium state in the buffered salt solution.

[0036] In some embodiments, specifically, the molecular weight of the polycaprolactone-polyethylene glycol copolymer is 10,000-200,000; the mass proportion of the polycaprolactone-polyethylene glycol copolymer in the amphiphilic biodegradable bone repair material is 20-90%.

[0037] Specifically, in this patent, by adjusting the ratio of polycaprolactone (hydrophobic) and polyethylene glycol (amphiphilic), a polycaprolactone-polyethylene glycol copolymer is prepared. The polymer has amphiphilic properties, having both hydrophilic and hydrophobic properties, and thus has plasticity and can be blended with inorganic materials, growth factors and buffered salt solutions.

[0038] In addition, the polymer in this patent has good plastic properties under 4-50°C conditions, without the need for high temperature conditions, overcoming the defect that existing plastic bone repair materials need high temperature heating to soften and shape.

[0039] In some embodiments, specifically, the molar ratio of the repeating unit of caprolactone in the polycaprolactone-polyethylene glycol copolymer is 30-60%.

[0040] In some embodiments, specifically, the polyethylene glycol in the polycaprolactone-polyethylene glycol copolymer includes any one of polyethylene glycol and polyethylene glycol monomethyl ether or a combination of both.

[0041] In some embodiments, specifically, the inorganic material includes any one or more combinations of hydroxyapatite, β-tricalcium phosphate, calcium carbonate and calcium silicate; the mass proportion of the inorganic material in the amphiphilic biodegradable bone repair material is 5-30%.

[0042] In some embodiments, specifically, the particle size of the inorganic material is in the range of 0.5-100 μm.

[0043] In some embodiments, specifically, the growth factor includes any one or a combination of BMP-2 and BMP-7 bone morphogenetic proteins; the dosage of the growth factor is 0.1-1 mg / mL.

[0044] The disclosed embodiment also provides a method for preparing the amphiphilic biodegradable bone repair material as described above, comprising the following steps: step S1, pre-loading polycaprolactone-polyethylene glycol copolymer, inorganic material, growth factor and buffered salt solution into a container according to a ratio and mixing them evenly; step S2, directly filling or freeze-drying the evenly mixed components to obtain the amphiphilic biodegradable bone repair material.

[0045] In some embodiments, specifically, the packaging form filled in step S2 includes prefilled syringes and vials. The former has the characteristic of being injectable, and can be directly pushed to the target position through a syringe and a catheter in a narrow space where operation is inconvenient, and then shaped into the target shape through surgical instruments.

[0046] The disclosed embodiments also provide an application of the above-mentioned amphiphilic biodegradable bone repair material in the field of orthopedics, which can be used for filling and repairing bone defects, bone nonunions, delayed bone healing, as well as spinal fusion, joint fusion and corrective bone grafting repair, and filling of non-load-bearing bone defects.

[0047] Example 1

[0048] (1) Add polycaprolactone-polyethylene glycol copolymer, hydroxyapatite particles with an average particle size of 80 μm, and BMP-2 powder into a syringe through a three-way pipe, and add phosphate solution; the molecular weight of polycaprolactone-polyethylene glycol copolymer is 20,000, the mass ratio is 50%, and the molar ratio of the repeating unit of caprolactone in the copolymer is 30%; the mass ratio of hydroxyapatite particles is 25%; the concentration of BMP-2 is 1 mg / mL; repeatedly push and squeeze to mix the three components evenly;

[0049] (2) After mixing, the mixture is filled into a prefilled syringe to obtain a final bone repair material product, which is tested at 4°C and found to have a plasticity effect.

[0050] like Figure 1 As shown, the bone repair material of Example 1 of the present invention is in the form of a prefilled product, and the syringe contains the bone transplant material, which can be directly pushed for use.

[0051] like Figure 2 As shown, the bone repair material of Example 1 of the present invention can be smoothly pushed out of the syringe and has excellent injectability.

[0052] Example 2

[0053] (1) Add polycaprolactone-polyethylene glycol copolymer, calcium carbonate particles with an average particle size of 100 μm, and BMP-7 powder into a syringe through a three-way pipe, and add phosphate solution; the molecular weight of polycaprolactone-polyethylene glycol copolymer is 10,000, the mass ratio is 90%, and the molar ratio of the repeating unit of caprolactone in the copolymer is 60%; the mass ratio of calcium carbonate particles is 5%; the concentration of BMP-7 is 0.5 mg / mL; repeatedly push and squeeze to mix the three components evenly;

[0054] (2) After mixing, the mixture is filled into vials and freeze-dried to obtain the final bone repair material product. The product is tested at 25°C and has a plasticizing effect.

[0055] Example 3

[0056] (1) Add polycaprolactone-polyethylene glycol copolymer, calcium silicate particles with an average particle size of 30 μm, and BMP-2 powder into a syringe through a three-way pipe, and add HEPES buffer; the molecular weight of polycaprolactone-polyethylene glycol copolymer is 50,000, the mass ratio is 35%, and the molar ratio of the repeating unit of caprolactone in the copolymer is 40%; the mass ratio of calcium silicate particles is 10%; the concentration of BMP-2 is 0.8 mg / mL; repeatedly push and squeeze to mix the three components evenly;

[0057] (2) After mixing, the mixture is filled into vials and freeze-dried to obtain the final bone repair material product. The product is tested at 20°C and has a plasticizing effect.

[0058] like Figure 3 As shown, the polycaprolactone-polyethylene glycol powder in the bone repair material prepared in Example 3 of the present invention is white after being freeze-dried.

[0059] like Figure 4-6 As shown, after the polycaprolactone-polyethylene glycol powder in the bone repair material prepared in Example 3 is mixed with the buffered salt solution, it can be molded into different shapes, and can also be molded into a desired shape according to demand to meet the filling of the defect site.

[0060] Example 4

[0061] (1) Add polycaprolactone-polyethylene glycol copolymer, β-tricalcium phosphate particles with an average particle size of 0.5 μm, and BMP-2 and BMP-7 powders into a syringe through a three-way pipe, and add phosphate buffer; the molecular weight of polycaprolactone-polyethylene glycol copolymer is 200,000, the mass ratio is 20%, and the molar ratio of the repeating unit of caprolactone in the copolymer is 50%; the mass ratio of β-tricalcium phosphate particles is 15%; the concentration of BMP-2 is 0.8 mg / mL, and the concentration of BMP-7 is 0.1 mg / mL; repeatedly push and squeeze to mix the three components evenly;

[0062] (2) After mixing, the mixture is filled into a prefilled syringe to obtain a final bone repair material product, which is tested at 50° C. The product has a plasticity effect.

[0063] Example 5

[0064] (1) Add polycaprolactone-polyethylene glycol copolymer, hydroxyapatite particles with an average particle size of 10 μm, calcium carbonate particles with an average particle size of 5 μm, and BMP-2 powder into a syringe through a three-way pipe, and add phosphate buffer; the molecular weight of polycaprolactone-polyethylene glycol copolymer is 100,000, the mass ratio is 24%, and the molar ratio of the repeating unit of caprolactone in the copolymer is 45%; the mass ratio of hydroxyapatite particles is 6%, and the mass ratio of calcium carbonate particles is 18%; the concentration of BMP-2 is 1 mg / mL; repeatedly push and squeeze to mix the three components evenly;

[0065] (2) After mixing, the mixture is filled into vials and freeze-dried to obtain the final bone repair material product. The product is tested at 25°C and has a plasticizing effect.

[0066] Example 6

[0067] (1) Add polycaprolactone-polyethylene glycol monomethyl ether copolymer, hydroxyapatite particles with an average particle size of 75 μm, and BMP-2 powder into a syringe through a three-way pipe, and add phosphate solution; the molecular weight of polycaprolactone-polyethylene glycol monomethyl ether copolymer is 40,000, the mass ratio is 68%, and the molar ratio of the repeating unit of caprolactone in the copolymer is 45%; the mass ratio of hydroxyapatite particles is 30%; the concentration of BMP-2 is 1 mg / mL; repeatedly push and squeeze to mix the three components evenly;

[0068] (2) After mixing, the mixture is filled into a prefilled syringe to obtain the final bone repair material product.

[0069] like Figure 7 As shown, the cell compatibility test of the bone repair material extracts of different concentrations in Example 6 of the present invention showed that the extracts ranging from 2.5 to 20 mg / mL did not produce significant toxicity to cells and had excellent cell compatibility. The product was tested at 40°C and had a plastic effect.

[0070] Example 7

[0071] (1) Add polycaprolactone-polyethylene glycol monomethyl ether copolymer, hydroxyapatite particles with an average particle size of 55 μm, and BMP-7 powder into a syringe through a three-way pipe, and add phosphate solution; the molecular weight of polycaprolactone-polyethylene glycol monomethyl ether copolymer is 60,000, the mass ratio is 30%, and the molar ratio of the repeating unit of caprolactone in the copolymer is 55%; the mass ratio of hydroxyapatite particles is 20%; the concentration of BMP-7 is 0.5 mg / mL; repeatedly push and squeeze to mix the three components evenly;

[0072] (2) After mixing, the mixture is filled into vials and freeze-dried to obtain the final bone repair material product.

[0073] Example 8

[0074] (1) Add polycaprolactone-polyethylene glycol copolymer, hydroxyapatite particles with an average particle size of 25 μm, and BMP-2 powder into a syringe through a three-way pipe, and add phosphate solution; the molecular weight of polycaprolactone-polyethylene glycol copolymer is 25,000, the mass ratio is 80%, and the molar ratio of the repeating unit of caprolactone in the copolymer is 50%; the mass ratio of hydroxyapatite particles is 30%; the concentration of BMP-2 is 0.9 mg / mL; repeatedly push and squeeze to mix the three components evenly;

[0075] (2) After mixing, the mixture is filled into a prefilled syringe to obtain a final bone repair material product, which is tested at 15° C. The product has a plasticity effect.

[0076] like Figure 8As shown, in order to prove whether the material will cause inactivation of growth factors, the osteogenic differentiation test of C2C12 cells was carried out after shaping. In the control group, the cells were not specially treated, so the secretion of the osteogenic marker alkaline phosphatase was not significant. In the positive control group, BMP-2 was directly added, and the cells secreted a large amount of alkaline phosphatase. The group that only added bone repair materials did not show alkaline phosphatase. The bone repair material group loaded with BMP-2 was still able to induce cells to produce a large amount of alkaline phosphatase, but not as much as the positive control group, because the loaded material needs to slowly release BMP-2. This result can prove that the material will not cause complete inactivation of growth factors and can maintain its biological activity after blending and shaping.

[0077] In summary, the amphiphilic biodegradable bone repair material and its preparation method and application are prepared by selecting an amphiphilic and easily shaped polycaprolactone-polyethylene glycol copolymer to combine with growth factors and inorganic materials to form a bone repair material. The growth factors can be adsorbed on the inorganic materials for sustained-release bone induction repair. Under normal clinical use conditions, a fully biodegradable shaping bone repair material can be obtained, while avoiding the influence of high temperature on existing products during bone defect filling.

[0078] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An amphiphilic biodegradable bone repair material, characterized in that: include: Polycaprolactone-polyethylene glycol copolymer, inorganic material, growth factor and buffered salt solution. The polycaprolactone-polyethylene glycol copolymer is easy to shape and is in a hydrophilic-hydrophobic balance state in the buffered salt solution. The growth factor is attached to the surface of the inorganic material to play a role in inducing bone regeneration.

2. The amphiphilic biodegradable bone repair material according to claim 1, characterized in that: The molecular weight of the polycaprolactone-polyethylene glycol copolymer is 10,000-200,000, and its mass proportion in the bone repair material is 20%-90%.

3. The amphiphilic biodegradable bone repair material according to claim 2, characterized in that: The polyethylene glycol in the polycaprolactone-polyethylene glycol copolymer includes: ethylene glycol and / or polyethylene glycol monomethyl ether.

4. The amphiphilic biodegradable bone repair material according to claim 3, characterized in that: The molar proportion of the repeating unit of caprolactone in the polycaprolactone-polyethylene glycol copolymer is 30-60%.

5. The amphiphilic biodegradable bone repair material according to claim 1, characterized in that: The average particle size of the inorganic material in the bone repair material is 0.5 μm-100 μm, and the mass proportion is 5%-30%.

6. The amphiphilic biodegradable bone repair material according to claim 5, characterized in that: The inorganic material includes any one or more of hydroxyapatite, β-tricalcium phosphate, calcium carbonate and calcium silicate.

7. The amphiphilic biodegradable bone repair material according to claim 1, characterized in that: The growth factor concentration is 0.1 mg / mL-1 mg / mL, and the growth factor includes: BMP-2 and / or BMP-7.

8. The amphiphilic biodegradable bone repair material according to claim 1, characterized in that: The molding temperature of the polycaprolactone-polyethylene glycol copolymer is 4-50°C, preferably 20-40°C.

9. A method for preparing the amphiphilic biodegradable bone repair material according to any one of claims 1 to 8, characterized in that: The steps include: Step S1, pre-loading polycaprolactone-polyethylene glycol copolymer, inorganic material, growth factor and buffer salt solution into a container according to a ratio and mixing them evenly; Step S2, directly filling or freeze-drying the mixed composition to obtain an amphiphilic biodegradable bone repair material.

10. Use of the amphiphilic biodegradable bone repair material according to any one of claims 1 to 8 in the field of orthopedics.

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