Adhesive hydrogel for periodontal tissue regeneration and method of making same

Abstract

The application discloses an adhesive hydrogel for periodontal tissue regeneration and a preparation method thereof. The adhesive hydrogel is prepared by taking gelatin and polyacrylic acid as main raw materials and by taking a photo-crosslinking method as a basis. The adhesive hydrogel has good tissue adhesion and can be tightly bonded on the surface of wet soft and hard tissues, thereby making up for the defect that a periodontal filling material is difficult to fix in the current clinical treatment. The adhesive hydrogel has high porosity after complete water absorption and swelling, and the pores on the surface and inside of the adhesive hydrogel are interconnected, so that the adhesive hydrogel can provide more space for the growth of periodontal tissues, and is suitable for cell ingrowth and periodontal tissue regeneration.

Description

Technical Field

[0001] This invention relates to the field of tissue engineering materials, and more specifically to an adhesive hydrogel for oral periodontal tissue regeneration and its preparation method. Background Technology

[0002] Tissue adhesives have been extensively studied recently, offering clinical advantages over surgical sutures, including ease of use and good sealing. However, existing liquid or hydrogel tissue adhesives have limitations, such as weak adhesion, low biocompatibility, poor mechanical properties, and limited functionality. Furthermore, these studies are often limited to soft tissue connections, such as skin and internal organs, with limited application to hard tissues.

[0003] The succinimide ester groups grafted onto gelatin-based crosslinked polyacrylic acid polymers can form covalent crosslinks with the amino groups in the collagen matrix, increasing adhesion affinity. The catechol groups of dopamine, by mimicking the structure of the adhesive amino acid 3,4-dihydroxyphenylalanine in mussel adhesive proteins, also exhibit high reactivity. Numerous medical tissue adhesives modified with dopamine can firmly adhere to various polymeric materials, metallic materials, and biological tissue surfaces.

[0004] Current literature shows that the prepared tissue adhesives have low porosity and pore size, which cannot meet the requirements of an ideal scaffold for tissue regeneration. Kai Chen et al. (Kai Chen. Advanced Functional Materials. 2023, 33, 2303836) developed a polyethylene glycol adhesive by acrylamide polyethylene glycol, which has low porosity and pore size, hardly absorbs water and swells, and its adhesion to soft tissue surfaces was only tested. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an adhesive hydrogel for the regeneration of oral periodontal tissues and its preparation method. The prepared adhesive hydrogel exhibits excellent tissue adhesion, bonding tightly to both moist soft and hard tissue surfaces, thus overcoming the difficulty in fixing current clinical periodontal filling materials. After fully absorbing water and swelling, this adhesive hydrogel possesses high porosity, with interconnected pores on its surface and internally, providing ample space for the growth of oral periodontal tissues, making it suitable for cell ingrowth and the regeneration of oral periodontal tissues.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned oral periodontal tissue engineering scaffold.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] An adhesive hydrogel for oral periodontal tissue regeneration, wherein the adhesive hydrogel is a porous scaffold with good tissue adhesion to both wet soft and hard tissue surfaces, and interconnected pores on the surface and inside after absorbing water and swelling, wherein the porosity is 75.28-89.73% and the pore size is 43-157 μm.

[0009] Furthermore, the adhesive hydrogel wet-bonds with various tissues or materials through hydrogen bonding and amide reaction.

[0010] A method for preparing an adhesive hydrogel for oral periodontal tissue regeneration, the method comprising the following steps:

[0011] Step (1) Dissolve gelatin in deionized water and heat at 60°C until it is completely dissolved to obtain the first mixed solution;

[0012] Step (2) Add dopamine powder to the first mixed solution and stir in the dark for 2 minutes to allow it to fully crosslink, thus obtaining the second mixed solution;

[0013] Step (3) Add sodium hydroxide solution to the second mixed solution and stir for 10 min to oxidize dopamine to obtain the third mixed solution;

[0014] Step (4) Add acrylic acid, gelatin methacrylate, N-hydroxysuccinimide acrylate and α-ketoglutaric acid to the third mixed solution obtained in step (3) and stir to obtain the fourth mixed solution;

[0015] Step (5) Add nano-hydroxyapatite to the fourth mixed solution obtained in step (4) and stir to obtain the fifth mixed solution;

[0016] Step (6) Degas the fifth mixed solution obtained in step (5) and add it to a quartz mold for ultraviolet crosslinking. After complete drying, the desired adhesive hydrogel is obtained.

[0017] Furthermore, the gelatin in step (1) is type A gelatin with a gel strength of 300, and the gel strength of GelMA is 90-100 with an extraction degree of 60%.

[0018] Further, the first mixed solution in step (1) is a 20 wt% aqueous solution of gelatin.

[0019] Furthermore, in step (2), the dopamine powder is 1% of the gelatin mass, the temperature is 60°C, the stirring time is 2 min, and the rotation speed is 100 r / min.

[0020] Further, in step (3), the sodium hydroxide solution is a 0.1N standard solution, added at a volume ratio of 1:1 with the second mixed solution, the stirring temperature is 25℃, the stirring time is 10min, and the stirring speed is 100r / min.

[0021] Further, in step (4), the concentration of acrylic acid is 3wt%, and the concentrations of gelatin methacrylate, N-hydroxysuccinimide acrylate, and α-ketoglutarate are 0.1wt%, 1wt%, and 0.3wt%, respectively. The stirring time is 5min and the stirring speed is 200r / min.

[0022] Furthermore, in step (5), the diameter of the nano-hydroxyapatite is <200nm, the concentration is 1.5wt%, the stirring time is 5min, and the rotation speed is 200r / min.

[0023] Furthermore, in step (6), the ultraviolet light wavelength is 360nm, the power is 20W, and the crosslinking time is 1h.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The present invention prepares an adhesive hydrogel by photocrosslinking under the synergistic effect of specific concentrations and ratios. This hydrogel has good tissue adhesion and high porosity after complete water absorption and swelling. The pores on its surface and inside are interconnected, which is conducive to cell and tissue growth, oxygen and nutrient transport, and excretion of metabolic products.

[0026] The adhesive hydrogel of this invention is a solid tape, which is easy to cut and use, and can meet the bonding needs of irregular shapes in clinical practice.

[0027] The porous structure of the adhesive hydrogel of the present invention gives it a large specific surface area, and the interconnected pores facilitate cell growth into the interior.

[0028] The adhesive hydrogel of the present invention has a high porosity after fully absorbing water and swelling, which can be as high as 75.28-89.73%, and the pore size is 43-157 μm, providing favorable conditions for the growth of cells and oral periodontal tissues, and facilitating the ingrowth of cells and oral periodontal tissues. Attached Figure Description

[0029] Figure 1 These are field emission scanning electron microscope images of the adhesive hydrogel of the present invention.

[0030] Figure 2 This is the infrared spectrum analysis diagram of the adhesive hydrogel of the present invention.

[0031] Figure 3 This is a field emission scanning electron microscope image of bone marrow mesenchymal stem cells one week after inoculation with the adhesive hydrogel of the present invention. Detailed Implementation

[0032] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0033] An adhesive hydrogel for periodontal tissue regeneration in the oral cavity is disclosed. The adhesive hydrogel exhibits good tissue adhesion to both moist soft and hard tissue surfaces. After absorbing water and swelling, the surface and internal pores are interconnected. The porosity is 75.28-89.73%, and the pore size is 43-157 μm. The adhesive hydrogel wet-bonds with various tissues or materials through hydrogen bonding and amide reactions.

[0034] A method for preparing an adhesive hydrogel for oral periodontal tissue regeneration, the method comprising the following steps:

[0035] Step (1) Dissolve gelatin in deionized water and heat at 60°C until completely dissolved to obtain a first mixed solution; the gelatin is type A gelatin with a gel strength of 300, and the gelMA has a gel strength of 90-100 and an extraction degree of 60%. The first mixed solution is a 20wt% gelatin aqueous solution.

[0036] Step (2) Add dopamine powder to the first mixed solution and stir for 2 minutes in the dark to allow it to fully crosslink, thus obtaining the second mixed solution; the dopamine powder is 1% of the gelatin mass, the temperature is 60℃, the stirring time is 2 minutes, and the speed is 100 r / min.

[0037] Step (3) Add sodium hydroxide solution to the second mixed solution and stir for 10 min to oxidize dopamine to obtain the third mixed solution; the sodium hydroxide solution is a 0.1N standard solution, and the volume ratio of sodium hydroxide solution to the second mixed solution is 1:1. The stirring temperature is 25℃, the stirring time is 10 min, and the stirring speed is 100 r / min.

[0038] In step (4), acrylic acid, gelatin methacrylate, N-hydroxysuccinimide acrylate, and α-ketoglutaric acid are added to the third mixed solution obtained in step (3) and stirred to obtain the fourth mixed solution. The concentration of acrylic acid is 3wt%, and the concentrations of gelatin methacrylate, N-hydroxysuccinimide acrylate, and α-ketoglutaric acid are 0.1wt%, 1wt%, and 0.3wt%, respectively. The stirring time is 5min and the stirring speed is 200r / min.

[0039] Step (5) Add nano-hydroxyapatite to the fourth mixed solution obtained in step (4) and stir to obtain the fifth mixed solution; the nano-hydroxyapatite has a diameter of <200nm, a concentration of 1.5wt%, a stirring time of 5min, and a rotation speed of 200r / min.

[0040] Step (6) Degas the fifth mixed solution obtained in step (5) and add it to a quartz mold for ultraviolet crosslinking. After complete drying, the desired adhesive hydrogel is obtained. The ultraviolet wavelength is 360nm, the power is 20W, and the crosslinking time is 1h.

[0041] The gelatin, dopamine, sodium hydroxide, acrylic acid, gelatin methacrylate, N-hydroxysuccinimide acrylate, α-ketoglutarate, and nano-hydroxyapatite used in the following examples were all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. The gelatin was type A gelatin with a gel strength of 300, the gelMA had a gel strength of 90-100 and an extraction rate of 60%, and the nano-hydroxyapatite had a diameter of <200nm.

[0042]

preparation

[0043] The preparation methods in the following examples all use the same method, namely:

[0044] Step (1) Dissolve gelatin in deionized water and heat at 60°C until it is completely dissolved to obtain the first mixed solution;

[0045] Step (2) Add dopamine powder to the first mixed solution and stir in the dark for 2 minutes to allow it to fully crosslink, thus obtaining the second mixed solution;

[0046] Step (3) Add sodium hydroxide solution to the second mixed solution and stir for 10 min to oxidize dopamine to obtain the third mixed solution;

[0047] Step (4) Add acrylic acid, gelatin methacrylate, N-hydroxysuccinimide acrylate and α-ketoglutaric acid to the third mixed solution obtained in step (3) and stir to obtain the fourth mixed solution;

[0048] Step (5) Add nano-hydroxyapatite to the fourth mixed solution obtained in step (4) and stir to obtain the fifth mixed solution;

[0049] Step (6) Degas the fifth mixed solution obtained in step (5) and add it to a quartz mold for ultraviolet crosslinking. After complete drying, the desired adhesive hydrogel is obtained.

[0050] The variables in the preparation process of Examples 1-10 are shown in Table 1:

[0051] Table 1

[0052]

[0053] [Characteristics]

[0054] like Figure 1 The image shows a field emission scanning electron microscope (FESEM) image of the prepared adhesive hydrogel, revealing that it contains a porous structure with interconnected pores.

[0055] The porosity of the adhesive hydrogels prepared in Examples 1-10 was measured using a pressure pump tester, and the pore size of the adhesive hydrogels was detected by microscopic imaging. The results are shown in Table 2.

[0056] Table 2

[0057]

[0058]

[0059] As can be seen from Table 2, the adhesive hydrogel prepared by the synergistic effect of specific concentration ratios and reaction times has both high porosity and large pore size. The porosity can reach up to 89.73%, the pore size can reach up to 157 μm, and the distribution of pores larger than 50 μm is as high as 95%, which provides favorable conditions for cell and oral periodontal tissue growth.

[0060] [Application Testing]

[0061] 1. Fourier transform infrared spectroscopy test

[0062] The adhesive hydrogel prepared in Example 2 was completely dried and then examined under a Fourier transform infrared spectrometer.

[0063] like Figure 2 The infrared spectrum analysis of the adhesive hydrogel shows that the absorption peaks are: 3319.40 cm⁻¹ for the stretching vibration of OH, 2925.23 cm⁻¹ for the stretching vibration of CH, 1702.69 cm⁻¹ for the stretching vibration of the C=O group of the ester group, 1629.38 cm⁻¹ for the stretching vibration of C=O (amide I band), 1538.89 cm⁻¹ for the skeletal vibration of the benzene ring, 1448.9 cm⁻¹ for the bending vibration of -CH₂-, 1408.89 cm⁻¹ for the stretching vibration of CN (amide III band), 1162.65 cm⁻¹ for the stretching vibration of CO, 1032.14 cm⁻¹ for the in-plane bending vibration of CH, and 797.51 cm⁻¹ for the out-of-plane bending vibration of CH. This indicates that the hydrogel adheres to various tissues or materials through hydrogen bonding and reaction with amides.

[0064] 2. Cell adhesion test

[0065] The adhesive hydrogel prepared in Example 2 was transferred to a 24-well cell culture plate, and 2 × 10⁶ oral periodontal pulp mesenchymal stem cells were seeded in each well. 4After one week of culture, the cells were fixed with 2.5% glutaraldehyde for 30 minutes, dehydrated with a gradient of 30%, 50%, 70%, and 90% ethanol, and then dehydrated three times with anhydrous ethanol. After drying, the cells were sputter-coated with gold and photographed under a field emission scanning electron microscope.

[0066] like Figure 3 This is a field emission scanning electron microscope image of oral periodontal pulp mesenchymal stem cells one week after being seeded into an adhesive hydrogel. It shows that the cells can adhere and grow on the surface of the hydrogel (indicated by the white arrow), indicating that the adhesive hydrogel has good cell compatibility.

[0067] This invention discloses an adhesive hydrogel for oral periodontal tissue regeneration and its preparation method. Using gelatin and polyacrylic acid as main raw materials, and based on a photocrosslinking method, the adhesive hydrogel is prepared. The adhesive hydrogel exhibits excellent tissue adhesion, bonding tightly to both moist soft and hard tissue surfaces, overcoming the current clinical shortcomings of periodontal filling materials that are difficult to fix. After fully absorbing water and swelling, the adhesive hydrogel possesses high porosity, with interconnected pores on its surface and inside, providing ample space for the growth of oral periodontal tissue, making it suitable for cell ingrowth and the regeneration of oral periodontal tissue.

[0068] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. An adhesive hydrogel for oral periodontal tissue regeneration, characterized in that: The adhesive hydrogel is a porous scaffold that exhibits tissue adhesion on both moist soft and hard tissue surfaces. After absorbing water and swelling, the pores on its surface and inside are interconnected, with a porosity of 75.28-89.73% and a pore size of 43-157 mm. The preparation method includes the following steps: Step (1) Dissolve gelatin in deionized water and heat at 60°C to completely dissolve it to obtain a first mixed solution; the gelatin is type A gelatin with a gel strength of 300, gelMA gel strength of 90-100, and extraction degree of 60%; the first mixed solution is a 20wt% gelatin aqueous solution. Step (2) Add dopamine powder to the first mixed solution and stir for 2 minutes in the dark to allow it to fully crosslink, thereby obtaining the second mixed solution; the dopamine powder is 1% of the gelatin mass, the temperature is 60℃, the stirring time is 2 minutes, and the rotation speed is 100 r / min; Step (3) Add sodium hydroxide solution to the second mixed solution and stir for 10 min to oxidize dopamine to obtain the third mixed solution; the sodium hydroxide solution is a 0.1N standard solution, and the volume ratio of sodium hydroxide solution to the second mixed solution is 1:

1. The stirring temperature is 25℃, the stirring time is 10 min, and the stirring speed is 100 r / min. Step (4) Add acrylic acid, gelatin methacrylate, N-hydroxysuccinimide acrylate, and α-ketoglutaric acid to the third mixed solution obtained in step (3) and stir to obtain a fourth mixed solution; the concentration of acrylic acid is 3wt%, and the concentrations of gelatin methacrylate, N-hydroxysuccinimide acrylate, and α-ketoglutaric acid are 0.1wt%, 1wt%, and 0.3wt%, respectively. The stirring time is 5min and the rotation speed is 200 r / min. Step (5) Add nano-hydroxyapatite to the fourth mixed solution obtained in step (4) and stir to obtain the fifth mixed solution; the nano-hydroxyapatite has a diameter of <200nm, a concentration of 1.5wt%, a stirring time of 5min, and a rotation speed of 200 r / min. Step (6) Degas the fifth mixed solution obtained in step (5) and add it to a quartz mold for ultraviolet crosslinking. After complete drying, the desired adhesive hydrogel is obtained. The ultraviolet wavelength is 360nm, the power is 20W, and the crosslinking time is 1h.

2. The adhesive hydrogel for oral periodontal tissue regeneration according to claim 1, characterized in that: The adhesive hydrogel bonds to tissues or materials wetly via hydrogen bonding and amide reaction.

3. A method for preparing an adhesive hydrogel for oral periodontal tissue regeneration as described in any one of claims 1-2, characterized in that, The preparation method includes the following steps: Step (1) Dissolve gelatin in deionized water and heat at 60°C to completely dissolve it to obtain a first mixed solution; the gelatin is type A gelatin with a gel strength of 300, gelMA gel strength of 90-100, and extraction degree of 60%; the first mixed solution is a 20wt% gelatin aqueous solution. Step (2) Add dopamine powder to the first mixed solution and stir for 2 minutes in the dark to allow it to fully crosslink, thereby obtaining the second mixed solution; the dopamine powder is 1% of the gelatin mass, the temperature is 60℃, the stirring time is 2 minutes, and the rotation speed is 100 r / min; Step (3) Add sodium hydroxide solution to the second mixed solution and stir for 10 min to oxidize dopamine to obtain the third mixed solution; the sodium hydroxide solution is a 0.1N standard solution, and the volume ratio of sodium hydroxide solution to the second mixed solution is 1:

1. The stirring temperature is 25℃, the stirring time is 10 min, and the stirring speed is 100 r / min. Step (4) Add acrylic acid, gelatin methacrylate, N-hydroxysuccinimide acrylate, and α-ketoglutaric acid to the third mixed solution obtained in step (3) and stir to obtain a fourth mixed solution; the concentration of acrylic acid is 3wt%, and the concentrations of gelatin methacrylate, N-hydroxysuccinimide acrylate, and α-ketoglutaric acid are 0.1wt%, 1wt%, and 0.3wt%, respectively. The stirring time is 5min and the rotation speed is 200 r / min. Step (5) Add nano-hydroxyapatite to the fourth mixed solution obtained in step (4) and stir to obtain the fifth mixed solution; the nano-hydroxyapatite has a diameter of <200nm, a concentration of 1.5wt%, a stirring time of 5min, and a rotation speed of 200 r / min. Step (6) Degas the fifth mixed solution obtained in step (5) and add it to a quartz mold for ultraviolet crosslinking. After complete drying, the desired adhesive hydrogel is obtained. The ultraviolet wavelength is 360nm, the power is 20W, and the crosslinking time is 1h.

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