CN113577371A

CN113577371A - Organic-inorganic hybrid hydrogel bone adhesive and preparation method thereof

Info

Publication number: CN113577371A
Application number: CN202110858919.4A
Authority: CN
Inventors: 张冰雁; 何湘; 韩宇晴; 罗蕴涵; 吴鑫; 奚桢浩; 赵玲; 王杰
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2021-11-02

Abstract

The invention discloses a preparation method of an organic-inorganic hybrid hydrogel bone cement, which comprises the following steps: (1) preparation of hydrogel precursor, (2) preparation of mineralized hydrogel precursor, (3) preparation of organic-inorganic hybrid hydrogel bone adhesive: taking the volume ratio of 1.5: and (3) stirring the solution A and the solution B in a ratio of 1-2: 1, and then injecting the solution A and the solution B into a reaction container to obtain the hydrogel with the three-dimensional reticular pore structure of the aminopolysaccharide @ aldehyde polysaccharide @ CaCO 3. According to the invention, the inorganic and aldehyde polysaccharide are uniformly mixed to form a pre-crosslinking solution, and then the pre-crosslinking solution and the buffer solution of the aminopolysaccharide are subjected to in-situ chemical reaction, so that the organic-inorganic hybrid hydrogel with a stable three-dimensional hole structure is formed.

Description

Organic-inorganic hybrid hydrogel bone adhesive and preparation method thereof

Technical Field

The invention relates to the technical field of bone cement, in particular to an organic-inorganic hybrid hydrogel bone cement and a preparation method thereof.

Background

When a human bone encounters a large fracture or defect, surgical intervention is required to fix the fractured tissue and promote healing. The traditional bone fixation operation is realized by adopting metal and screws, and the method has the following defects: (1) the operation wound surface is large and is not beneficial to postoperative healing, (2) various postoperative complications such as infection, healing deformity and internal fixation dislocation are easily caused; (3) easily causes osteoporosis or metal absorption to cause fixing looseness; (4) requiring surgical removal, increasing the risk of infection and, at the same time, increasing patient pain.

The medical bone adhesive is a novel fracture fixing material, has the advantages of simple operation, small using amount, stable performance, easy shaping and the like, can overcome the problems of heaviness, easy infection and the like caused by metal internal fixation, and can greatly reduce the probability of postoperative complications. The current mature medical bone adhesive products comprise a-cyanoacrylate adhesive, polymethyl methacrylate (PMMA), calcium phosphate medical adhesive (CPC) and magnesium phosphate medical adhesive (MPC). The higher exothermic temperature during the use of alpha-cyanoacrylate adhesives and PMMA can lead to thermal and chemical necrosis of the bone. Meanwhile, the alpha-cyanoacrylate and the PMMA have certain toxicity, are easy to generate foreign body reaction and have poor biocompatibility; CPC and MPC are safe and non-toxic, do not produce foreign body reaction, have good biocompatibility, but the two adhesives have the disadvantages of poor mechanical properties, weak binding properties, and easy collapse when contacting body fluid, possibly aggravating bone destruction. Therefore, there is a clinical need for a bone cement with good biocompatibility and mechanical properties.

Hydrogel (Hydrogel) is a cross-linked polymer with a three-dimensional network structure, and has become a popular research material in the fields of tissue adhesives, drug sustained release carriers, tissue engineering scaffolds and the like due to the characteristics of various synthesis modes and easy modification. Sehl et al in U.S. Pat. No.2003/0119985 and Goldmann in U.S. Pat. No.2005/0002893 disclose several hydrogel tissue adhesives with improved adhesion and non-toxic functionality, which form a crosslinked network via covalent bonds through nucleophilic groups.

J.Zhang, Fuzhou university, for "functional Double-Network Hydrogels for Applications in removal and in Low-Temperature Structure Sensing", applied. Mater. interfaces, 2020-12-27, 30247-30258, discloses a novel bone cement design strategy capable of providing stable fracture fixation and accelerating bone regeneration during bone remodeling, which comprises a binder with Tannic Acid (TA) as phenolic glue molecules, spontaneously co-assembling with fibroin (SF) and Hydroxyapatite (HA), to obtain an inorganic-organic hybrid hydrogel (SF @ TA @ HA), which HAs good biocompatibility and biodegradability, can promote bone regeneration early in vivo, and HAs good mechanical strength and adhesion properties. However, the hydroxyapatite in the technology generates free phosphate ions after gelation, and the phosphate ions can enter the body along with the gelation after protein absorption and metabolism.

Disclosure of Invention

The invention aims to provide a hydrogel bone adhesive and a preparation method thereof, which takes aldehyde polysaccharide and amino polysaccharide as raw materials,the organic-inorganic hybrid hydrogel prepared by the inorganic mineral substances has stronger mechanical strength, waterproof adhesion performance and biocompatibility, can be used as a bone adhesive to be directly used for bonding broken ends of fractures and CaCO generated by reaction₃And has the advantages of promoting the growth of osteocyte, strong operability and low cost.

In order to achieve the purpose of the invention, the technical scheme of the invention is as follows: a preparation method of an organic-inorganic hybrid hydrogel bone cement comprises the following steps:

(1) preparation of hydrogel precursor: mixing a polysaccharide polymer and sodium periodate according to a mass ratio of 1.5: 1-2: 1, dissolving in a phosphate buffer solution (I), and carrying out a light-shielding reaction at room temperature; putting the reacted mixture into a dialysis bag, dialyzing with ultrapure water and freeze-drying to obtain a hydrogel precursor;

(2) preparing a mineralized hydrogel precursor: preparing a hydrogel precursor solution by taking a phosphate buffer solution (II) as a solvent; dissolving the hydrogel precursor solution in CaCl₂Uniformly mixing the solution to obtain a solution A;

preparing amino polysaccharide solution, mixing the amino polysaccharide solution with Na₂CO₃Uniformly mixing the solution to obtain a solution B;

(3) preparation of organic-inorganic hybrid hydrogel bone cement: taking the volume ratio of 1.5: and (3) stirring the solution A and the solution B in a ratio of 1-2: 1, and then injecting the solution A and the solution B into a reaction container to obtain the hydrogel with the three-dimensional reticular pore structure of the aminopolysaccharide @ aldehyde polysaccharide @ CaCO 3.

Preferably, the aminopolysaccharide comprises Chitosan (CS) and derivatives thereof; the polysaccharide polymer comprises at least one of Hyaluronic Acid (HA), sodium alginate (NaAlg), or sodium carboxymethylcellulose (CMC).

Preferably, the pH of the phosphate buffer solution (i) is 5.0; the pH of the phosphate buffer solution (ii) was 7.4.

Preferably, the mass ratio of the polysaccharide polymer to the sodium periodate is 1: 1.5-2: 1.

Preferably, the reaction time in step (1) is 5 to 72 hours.

Preferably, the stepsThe solution A in the step (2) is aldehyde polysaccharide @ CaCl₂Pre-crosslinking solution of CaCl₂Distributed on the surface of aldehyde polysaccharide macromolecules.

Preferably, Na in step (3)₂CO₃With CaCl₂Is an in situ reaction.

As another object of the present invention, an organic-inorganic hybrid hydrogel bone cement comprising a hydrogel having the amino polysaccharide @ aldehyde polysaccharide @ CaCO, prepared by the above method₃The size of the three-dimensional mesh hole structure is 50-200 microns.

The invention discloses a hydrogel bone adhesive, wherein a polysaccharide polymer is used as a raw material, and an inorganic mineralized precursor of aminopolysaccharide is combined to prepare the hydrogel bone adhesive with aminopolysaccharide @ aldehyde polysaccharide @ CaCO₃The bone cement in hydrogel form with a three-dimensional reticular pore structure. The inorganic mineralized precursor of the aminopolysaccharide is prepared by mixing a buffer solution of aldehyde group polysaccharide with CaCO₃Mixing, modifying aldehyde polysaccharide with inorganic molecule, CaCO₃The molecules are arranged on the surface of the aldehyde polysaccharide macromolecule to form aldehyde polysaccharide @ CaCl₂Pre-crosslinking solution, i.e. inorganic mineralized precursor. Then aldehyde polysaccharide @ CaCl₂Mixing the pre-crosslinking solution with a buffer solution of amino polysaccharide, and carrying out Schiff reaction on aldehyde group in aldehyde polysaccharide and amino group on a side chain of the amino polysaccharide to generate Schiff base covalent bond; at the same time, Na₂CO₃With CaCl₂Reaction in situ generation of CaCO₃To produce a curing reaction, CaCO₃Nucleation promotes the self-assembly reaction of the gel due to Ca²⁺The amino polysaccharide is uniformly distributed on the surface of the aldehyde polysaccharide, so that the amino polysaccharide can be uniformly dispersed on the surface of the aldehyde polysaccharide, the organic-inorganic interface binding force is enhanced, the three components are promoted to form firm chemical binding force, and the stable organic-inorganic hybrid hydrogel with a three-dimensional pore structure is formed. The buffer solution is phosphate buffer solution, and provided phosphate ions can be combined with Ca ions in the gel to induce generation of apatite mineral substances and promote healing of bone tissues.

Promoting the generation of amino polysaccharide @ aldehyde polysaccharide @ CaCO₃The three-dimensional hydrogel forms tissue adhesion due to CaCO in the hydrogel₃The existence of the molecules ensures that the organic-inorganic hybrid hydrogel has certain mechanical strength compared with other hydrogels. Therefore, when the invention is used as a bone cement, the invention keeps the super-strong adhesion performance and has obvious mechanical properties. Fixing the bone cement to the bone fracture end, wherein CaCO₃Slow release of Ca²⁺And deposited in bone tissue to promote the differentiation of stem cells in the osteogenic direction. As biodegradable aminopolysaccharide and aldehydic polysaccharide polymer, it has good biocompatibility, and promotes the growth of cells and new tissue in the degradation process of aminopolysaccharide and aldehydic polysaccharide, and the new tissue can gradually replace hydrogel, Ca²⁺Promotes the new bone tissue to form a compact matrix so as to repair/heal the broken end, and the new bone tissue has certain fracture resistance.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

the organic-inorganic hybrid hydrogel with a stable three-dimensional hole structure is formed by uniformly mixing inorganic and aldehyde polysaccharide to form a pre-crosslinking solution and then carrying out in-situ chemical reaction with a buffer solution of aminopolysaccharide. The bone cementing agent of the invention has simple gelling process and CaCO generated by inorganic mineralization₃The mechanical property of the hydrogel can be enhanced, the hydrogel can be used as a crystal nucleus to accelerate the gelling speed of the hydrogel, the crosslinking time is shortened, the operation is simple, the crosslinking can be realized only by measuring the amount of solution, and the inorganic mineral substance is wrapped in the three-dimensional structure of the hydrogel, so that the stability is improved.

Drawings

FIG. 1 is an appearance of hydrogel of example 1 of the present invention.

FIG. 2 scanning electron microscope photograph of hydrogel of example 1 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the specific contents of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

The inorganic mineralized particles in this example are CaCO₃The form exists in the hydrogel, and the hydrogel forms a support with physical strength, thereby making up the defect of support of the aminopolysaccharide-aldehyde group polysaccharide hydrogel as an adhesive to limit the clinical application of the aminopolysaccharide-aldehyde group polysaccharide hydrogel in bone adhesion.

The invention provides a preparation method of a hydrogel bone adhesive, which comprises the following steps:

(1) preparing a hydrogel precursor;

mixing a polysaccharide polymer and sodium periodate according to the proportion of 1.5: 1-2: 1, dissolving the mixture in a phosphate buffer solution (I), and reacting for 5-72 hours at room temperature in a dark place; putting the reacted mixture into a dialysis bag with the molecular weight cutoff of 1000, dialyzing and freeze-drying to obtain aldehyde polysaccharide as a hydrogel precursor;

(2) preparation of mineralized hydrogel precursor

Preparing a hydrogel precursor solution by taking a phosphate buffer solution (II) as a solvent; dissolving the hydrogel precursor solution prepared in the step (1) in CaCl₂Uniformly mixing the solution to obtain a solution A;

(3) preparation of organic-inorganic hybrid hydrogel bone adhesive

Adding the solution A and the solution B in a volume ratio of 1: 5-2: 1 into a reaction container in a stirring state to obtain the polysaccharide with amino groups @ aldehyde groups @ CaCO₃An organic-inorganic hybrid hydrogel bone adhesive with a three-dimensional reticular pore structure.

In the embodiment of the invention, the used materials and reagents are respectively:

chitosan (Chitosan or CS, Sigma-Aldrich); hyaluronic acid (Hyaluronic acid or HA, Sigma-Aldrich); sodium alginate (Sodium alginate or SA or NaAlg, Sigma-Aldrich); sodium periodate (NaIO)₄Chemical reagents of Chengdu Kelong); sodium carbonate (Na)₂CO₃Chemical reagents of Chengdu Kelong); phosphate buffered saline (PBS, pH 5.0, pH 7.4, idenescenet initiators, ltd); ethylene glycol (C)₂H₆O₂Chemical reagents of Chengdu Kelong); calcium chloride (CaCl)₂Chemical reagents of Chengdu Kelong); dialysis bag (cellulose dialysis bag, molecular cut-off 10000kDa, Nanjing Sen Bega Biotech Co., Ltd.); the above reagents or other reagents are analytically pure.

Example 1

1. Preparation of aldehyde group hyaluronic acid

2.0g of hyaluronic acid having a molecular weight of 200 ten thousand and 1g of sodium periodate were dissolved in 200mL of PBS (pH 5.0), and stirred at room temperature for 72 hours in the absence of light. After completion of the reaction, 2mL of ethylene glycol was added to the reaction mixture to neutralize excess sodium periodate, and the mixture was stirred for 1 hour to allow the reaction to proceed sufficiently. After the reaction was terminated, the mixture was dialyzed in ultrapure water for 2 days with a dialysis bag having a molecular cut-off of 10000 and lyophilized to obtain aldehyde-based hyaluronic acid (AHA).

2. Preparation of mineralized hydrogel precursor

Preparing 20mg/mL aldehyde hyaluronic acid solution: 0.02g of aldehyde-based hyaluronic acid was weighed and added to 1mL of PBS buffer solution (pH 7.4).

Preparing 20mg/mL CaCl₂Solution: weighing 0.02g CaCl₂Added to 1mL of PBS buffer (pH 7.4).

Mixing the prepared aldehyde hyaluronic acid solution with CaCl₂The solutions were mixed well to obtain mixed solution a.

Preparing 20mg/mL carboxymethyl chitosan (CMCS) solution: 0.02g of carboxymethyl chitosan was weighed into 1mL of PBS buffer solution (pH 7.4).

Prepared with 20mg/mL of Na₂CO₃Solution: weighing 0.02g of Na₂CO₃Added to 1mL of PBS buffer (pH 7.4).

Mixing carboxymethyl chitosan solution with Na₂CO₃The solution is mixed evenly to obtain solution B.

3. Hydrogel preparation

Respectively filling 2mL of the solution A and 2mL of the solution B into two 5mL injectors, respectively filling the two injectors into two injection pumps at injection speeds of 1mL/min, uniformly injecting the two solutions into a continuously stirred reaction vessel, stopping stirring after the reaction liquid is completely injected, standing for 1min, observing that the liquid in the reactor does not flow and milky hydrogel is generated, and thus obtaining the hyaluronic acid-carboxymethyl chitosan-calcium carbonate hydrogel.

Example 2

1. Preparation of aldehyde group hyaluronic acid

3.0g of hyaluronic acid having a molecular weight of 200 ten thousand was dissolved in 200mL of PBS (pH 5.0), and stirred for 8 hours. 2g of sodium periodate was added to the stirred hyaluronic acid solution, and stirred at room temperature for 12 hours in the dark. After the reaction, 4mL of ethylene glycol was added to the reaction solution, stirred for 1 hour, and the reaction mixture was dialyzed in ultrapure water for 2 days with a dialysis bag having a molecular cut-off of 10000 and lyophilized to obtain aldehyde-based hyaluronic acid (AHA).

2. Preparation of mineralized hydrogel precursor

Preparing 20mg/mL aldehyde group hyaluronic acid (AHA) solution: 0.02g of aldehyde-based hyaluronic acid was weighed and added to 1mL of PBS buffer solution (pH 7.4). Preparing CaCl with 5mg/mL₂Solution: weighing 0.005g of CaCl₂Added to 1mL of PBS buffer (pH 7.4); mixing the prepared aldehyde hyaluronic acid solution with CaCl₂The solutions were mixed well to obtain mixed solution a.

Preparing 20mg/mL hydroxyethyl chitosan solution: 0.02g of hydroxyethyl chitosan (NOCC) was weighed into 1mL of PBS buffer solution (pH 7.4). Preparing 5mg/mL of Na₂CO₃Solution: 0.005g of Na was weighed₂CO₃Added to 1mL of PBS buffer (pH 7.4). Mixing hydroxyethyl chitosan solution with Na₂CO₃The solution is mixed evenly to obtain solution B.

3. Hydrogel preparation

Respectively filling 4mL of the solution A and 2mL of the solution B into two 5mL injectors, respectively fixing the injectors in two injection pumps, setting the injection speed to be 1mL/min, injecting the two solutions into a continuously stirred reaction vessel at a constant speed, stopping stirring after injection, standing for 1min, and obtaining the hyaluronic acid-hydroxyethyl chitosan-calcium carbonate hydrogel after the liquid in the reactor does not flow and milky white hydrogel is generated.

Experimental example 3

1. Preparation of aldehyde sodium alginate

2.0g of sodium alginate having a molecular weight of 150 ten thousand was dissolved in 200mL of PBS (pH 5.0), and stirred for 8 to 12 hours. 2g of sodium periodate was added to the stirred sodium alginate solution, and stirred at room temperature for 36 hours in the dark. After the reaction is finished, adding 4mL of glycol into the reaction solution, stirring for 1h, dialyzing the reaction mixture in ultrapure water for 2 days by using a dialysis bag with the molecular cut-off of 10000, and freeze-drying to obtain the aldehyde sodium alginate.

2. Preparation of mineralized hydrogel precursor

Preparing 20mg/mL aldehyde sodium alginate solution: 0.02g of the aldehyde sodium alginate prepared in step 1 was weighed and added to 1mL of PBS buffer solution (pH 7.4).

CaCl with 100mg/mL configuration₂Solution: weighing 0.1g of CaCl₂Added to 1mL of PBS buffer (pH 7.4). Mixing the prepared aldehyde hyaluronic acid solution with CaCl₂The solutions were mixed well to obtain mixed solution a.

Configuring 100mg/mL of Na₂CO₃Solution: 0.1g of Na was weighed₂CO₃Added to 1mL of PBS buffer (pH 7.4). Mixing carboxymethyl chitosan solution with Na₂CO₃The solution is mixed evenly to obtain solution B.

3. Hydrogel preparation

Respectively filling 3mL of the solution A and 2mL of the solution B into two 5mL injectors, respectively filling the two injectors into two injection pumps at injection speeds of 1mL/min, uniformly injecting the two solutions into a continuously stirred reaction vessel, stopping stirring after the reaction liquid is completely injected, standing for 1min, observing that the liquid in the reactor does not flow and milky hydrogel is generated, and thus obtaining the sodium alginate-carboxymethyl chitosan-calcium carbonate hydrogel.

Example 4

1. Preparation of aldehyde hydroxymethyl cellulose sodium

Sodium carboxymethylcellulose (CMC) 2.0g having a molecular weight of 180 ten thousand was dissolved in PBS 200mL (pH 5.0), and stirred for 10 to 12 hours. 3g of sodium periodate was added to the stirred sodium carboxymethylcellulose solution, and stirred at room temperature in the dark for 5 hours. After the reaction is finished, 6mL of ethylene glycol is added into the reaction solution, the mixture is stirred for 1h, and the reaction mixture is dialyzed in ultrapure water for 2 days by a dialysis bag with the molecular cut-off of 10000 and is freeze-dried to obtain the aldehyde hydroxymethyl cellulose sodium.

2. Preparation of mineralized hydrogel precursor

Preparing 20mg/mL of aldehyde hydroxymethyl cellulose sodium solution: 0.02g of sodium formaldehyde-methylol cellulose was weighed into 1mL of PBS buffer (pH 7.4).

Preparing 20mg/mL CaCl₂Solution: weighing 0.02g CaCl₂Added to 1mL of PBS buffer (pH 7.4). Mixing the prepared aldehyde hyaluronic acid solution with CaCl₂The solutions were mixed well to obtain mixed solution a.

Prepared with 20mg/mL of Na₂CO₃Solution: weighing 0.02g of Na₂CO₃Added to 1mL of PBS buffer (pH 7.4). Mixing carboxymethyl chitosan solution with Na₂CO₃The solution is mixed evenly to obtain solution B.

3. Hydrogel preparation

Respectively filling 4mL of the solution A and 2mL of the solution B into two 5mL injectors, respectively filling the two injectors into two injection pumps at injection speeds of 1mL/min, uniformly injecting the two solutions into a continuously stirred reaction vessel, stopping stirring after the reaction liquid is completely injected, standing for 1min, observing that the liquid in the reactor does not flow and milky hydrogel is generated, and thus obtaining the sodium carboxymethylcellulose-carboxymethyl chitosan-calcium carbonate hydrogel.

Comparative example 1

Dissolving 2.0g of hyaluronic acid with the molecular weight of 200 ten thousand and 1g of sodium periodate in 200mL of PBS (pH is 5.0), adding the mixture into 2mL of ethylene glycol after the reaction is finished, dialyzing the mixture in ultrapure water for 2 days by using a dialysis bag with the molecular cut-off of 10000 after the reaction is finished, and carrying out freeze-drying treatment to obtain aldehyde hyaluronic acid. 0.02g of aldehyde hyaluronic acid was weighed and added to 1mL of PBS buffer solution (pH 7.4) to obtain 20mg/mL of aldehyde hyaluronic acid solution.

0.02g of carboxymethyl chitosan was weighed into 1mL of PBS buffer solution (pH 7.4) to obtain a 20mg/mL carboxymethyl chitosan solution.

Respectively filling 2mL of aldehyde hyaluronic acid solution and 2mL of carboxymethyl chitosan into two 5mL syringes, respectively filling the syringes into two injection pumps, respectively, wherein the injection speed is 1mL/min, injecting the two solutions into a continuously stirred reaction container at a constant speed, stopping stirring after the reaction solution is completely injected, and standing to obtain the hyaluronic acid-carboxymethyl chitosan hydrogel.

Comparative example 2

Dissolving 2.0g of sodium alginate with the molecular weight of 150 ten thousand and 1g of sodium periodate in 200mL of PBS (pH is 5.0), adding the mixture into 2mL of ethylene glycol after the reaction is finished, dialyzing the mixture in ultrapure water for 2 days by using a dialysis bag with the molecular cut-off of 10000 after the reaction is finished, and carrying out freeze-drying treatment to obtain the aldehyde sodium alginate. 0.02g of aldehydic sodium alginate was weighed and added to 1mL of PBS buffer solution (pH 7.4) to obtain a 20mg/mL aldehydic sodium alginate solution.

Respectively filling 2mL of aldehyde sodium alginate solution and 2mL of carboxymethyl chitosan into two 5mL syringes, respectively filling the syringes into two injection pumps, respectively, wherein the injection speed is 1mL/min, injecting the two solutions into a continuously stirred reaction vessel at a constant speed, stopping stirring after the reaction solution is completely injected, and standing to obtain the sodium alginate-carboxymethyl chitosan hydrogel.

The adhesion performance and the mechanical performance of the experimental examples 1 to 4 and the comparative examples 1 to 2 were respectively tested. See table 1 for results.

The invention respectively tests the adhesion performance of the examples 1-4 and the comparative examples 1-2, and the test method comprises the following steps: the cancellous bone portion of the fresh porcine long epiphyseal bone was sawn into fixed-shape cuboids using a wire saw, and all bone pieces were sawn and stored in PBS buffer (pH 7.4) prior to the experiment. According to the above-mentioned gelling method, 20. mu.L of bone cement to be gelled in different groups is injected into the interface of the spongy bone to be bonded, and simultaneously the bone block to be bonded is fixed on the above-mentioned interface, and the bonded bone block is placed at room temperature for 10min so as to make the bone cement fully act. The cemented bone pieces were then placed in PBS solution for further mechanical testing; the maximum breaking strength of the bonded face of the bonded bone pieces in the vertical end-to-end direction was tested using a universal mechanical tester.

The mechanical properties of the invention were tested in terms of both compression and tensile modulus, and the results are shown in Table 1. The test method comprises the following steps: the hydrogel bone adhesives of examples 1 to 4 and comparative examples 1 to 2 were injected into a dumbbell-shaped mold, respectively, and sufficiently gelled for 10min, then taken out of the mold, immersed in a PBS solution, and placed in a constant temperature shaking table at 37 ℃ for overnight oscillation, and then the compressive modulus and tensile modulus of the sample were tested using a general mechanical tester, the compressive rate was set to 5mm/min and the tensile rate was set to 10mm/min during the test, a force value-deformation curve was obtained, a stress-strain curve was obtained by conversion, and the compressive modulus and tensile modulus after gelling the hydrogel bone adhesive were obtained, respectively, based on the slope of the curve at the origin.

	Adhesion Properties/KPa	Compressive modulus/KPa	Tensile modulus/KPa
				Example 1	77.3	69.8	68.3
Example 2	71.4	56.8	41.2
				Example 3	73.1	63.1	55.8
Example 4	72.9	66.3	42.4
				Comparative example 1	65.7	48.3	35.5
Comparative example 2	68.8	50.2	39.2

As can be seen from the above results, the organic-inorganic hybrid water formed by mineralization is directed to the adhesion propertiesThe gel is used as a bone binder, the broken ends of the broken bones are subjected to an end-to-end tensile test, the adhesion performance is slightly improved, and the end-to-end breaking strength of the broken ends of the example 1 and the comparative example 1 is basically kept unchanged, namely the hyaluronic acid-carboxymethyl chitosan adopts CaCl₂The effect of improving the adhesion performance is most obvious after the mineralization modification is carried out. And the compression modulus and the tensile modulus are both obviously improved relative to the comparison example.

The hydrogel prepared in example 1 and comparative example 1 was used as a bone cement to evaluate the effect of treatment on rat femoral fractures.

10 SD rats were randomly divided into two groups of 5 rats each. The femur of each rat was fractured and bone cement treatment was performed on the fractured ends, all other conditions being the same.

The first group used example 1 as the bone cement and the second group used control group 2 as the bone cement.

Fracture resistance tests were performed 50 days later on fractured femurs.

Fixing the femur, loading mechanical pressure of 20MPa, 30MPa and 50MPA respectively, and detecting fracture resistance of the femur under the same conditions.

The test finds that: in the 5 groups of test femurs of comparative example 1, secondary femoral fractures occurred at 30 MPa. The test case remained intact at 50MPa, showing the same fracture resistance as normal rat femur.

It is evident that example 1, as a bone cement, exhibits an effective mechanical strength in the treatment of fractured bone tissue, which is significantly superior to the control example without inorganic mineralization, and in clinical trials, its mechanical properties enable a rapid post-operative load-bearing capacity at the fracture site.

Referring to FIG. 1, an appearance of the hydrogel of this example 1 is shown, which has a smooth and flat appearance and elasticity.

Referring to fig. 2, which is a structure diagram (SEM diagram) of the electron microscope of this embodiment 1, it can be seen that the hydrogel of this embodiment 1 has an obvious three-dimensional network pore structure, and the size of the pores is 50 to 200 μm. The adhesion capacity of the hydrogel is increased due to the presence of pores of non-uniform size.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A preparation method of an organic-inorganic hybrid hydrogel bone cement comprises the following steps:

2. The method of preparing an organic-inorganic hybrid hydrogel bone cement of claim 1 wherein the aminopolysaccharide comprises Chitosan (CS) and its derivatives; the polysaccharide polymer comprises at least one of Hyaluronic Acid (HA), sodium alginate (NaAlg), or sodium carboxymethylcellulose (CMC).

3. The method for preparing an organic-inorganic hybrid hydrogel bone cement according to claim 1, wherein the phosphate buffer solution (i) has a pH of 5.0; the pH of the phosphate buffer solution (ii) was 7.4.

4. The method for preparing the organic-inorganic hybrid hydrogel bone cement as claimed in claim 1, wherein the mixing mass ratio of the polysaccharide polymer and the sodium periodate is 1.5: 1-2: 1.

5. The method for preparing the organic-inorganic hybrid hydrogel bone cement as claimed in claim 1, wherein the reaction time in the step (1) is 5-72 hours.

6. The method for preparing an organic-inorganic hybrid hydrogel bone cement as claimed in claim 1, wherein the solution A in step (2) is aldehyde polysaccharide @ CaCl₂Pre-crosslinking solution of CaCl₂The molecules are uniformly distributed on the surface of the aldehyde polysaccharide macromolecules.

7. The method for preparing an organic-inorganic hybrid hydrogel bone cement of claim 6, wherein in step (3), Na is added₂CO₃With CaCl₂Is an in situ reaction.

8. An organic-inorganic hybrid hydrogel bone cement prepared by the method of any one of claims 1 to 7, comprising a hydrogel having an aminopolysaccharide @ aldehydic polysaccharide @ CaCO₃The three-dimensional reticular pore structure.

9. The organic-inorganic hybrid hydrogel bone cement of claim 8, wherein the size of the three-dimensional network pores is 50 to 200 μm.