A hydrogel precursor solution and a preparation method thereof, and a hydrogel and a preparation method thereof

Abstract

The present invention relates to a hydrogel precursor liquid and a preparation method thereof, as well as a hydrogel and a preparation method thereof. The hydrogel precursor liquid of the present invention, it includes: a precursor liquid A, a precursor liquid B and a photocrosslinking agent, the precursor liquid A is a polyethylene glycol diacrylate solution, the precursor liquid B is a solution of one or more of gelatin, hyaluronic acid, chitosan, sodium alginate or starch, wherein the mass ratio of the precursor liquid A and the precursor liquid B is precursor liquid A / precursor liquid B=90:10-70:30. The hydrogel obtained by the hydrogel precursor liquid of the present invention has both high viscosity, biocompatibility and degradability, and when applied to dynamic and moist mucosa, it is stably fitted during the treatment period and degraded by itself after treatment; compatible with flexibility and stretchability: strong anatomical compliance and high stretchability, it can completely fit the gullies where conventional treatment cannot be administered.

Description

Technical Field

[0001] The invention relates to a hydrogel precursor solution and a preparation method thereof, as well as a hydrogel and a preparation method thereof, and belongs to the field of polymer biomaterials. Background Art

[0002] In biomedical application scenarios, hydrogels are often required to adhere to the tissue surface as biomedical adhesive materials. Compared with general adhesive materials, biomedical adhesive materials require special properties such as higher biocompatibility and mechanical properties matching the human body, and have attracted more attention from researchers.

[0003] At present, biomedical adhesive materials are mainly used in medical treatment to seal or stop bleeding of wounds caused by injuries or surgery. In this field, the introduction of biomedical adhesive materials is mainly to assist or replace suture materials, surgical nails or surgical clips used in traditional surgery. This type of traditional invasive material can cause secondary damage to patients, causing infection, leakage, and aesthetic problems, and it is difficult to apply to tissues such as dura mater, urethra, lung tissue, and nerves. Therefore, people have turned to the development of many non-invasive biomedical adhesive materials in order to solve the problems of traditional methods. It is estimated that biomedical adhesive materials (hemostatic agents, sealants and adhesives) have a market size of US$38 billion in 2017.

[0004] Among these materials, fibrin glue (such as ), albumin-based adhesive materials (such as ), polyethylene glycol (PEG) based adhesive materials (such as ) and cyanoacrylate-based adhesives (such as DermaBond Advanced TM , ) etc. However, these commercially available adhesive materials cannot completely replace traditional techniques such as sutures. The main reason is that their adhesion ability is not strong enough and their biocompatibility is poor. For example, the adhesion energy of fibrin glue and PEG-based adhesive materials is low, at 10 J / m 2 The degradation products of cyanoacrylate-based adhesive materials have certain cytotoxicity. Therefore, the development of new biomedical adhesive materials with both high adhesion and biocompatibility has become a research topic that has attracted widespread attention in recent years. Summary of the invention

[0005] Problem that the invention aims to solve

[0006] In order to solve the above problems in the prior art, the present invention provides a hydrogel precursor solution and a preparation method thereof, as well as a hydrogel obtained by the hydrogel precursor solution and a preparation method thereof. The hydrogel of the present invention has high viscosity, biocompatibility and degradability.

[0007] Solutions for solving problems

[0008] The present invention provides a hydrogel precursor solution, which comprises: a precursor solution A, a precursor solution B and a photocrosslinking agent, wherein the precursor solution A is a polyethylene glycol diacrylate solution, and the precursor solution B is a solution of one or more of gelatin, hyaluronic acid, chitosan, sodium alginate or starch.

[0009] Wherein, the mass ratio of the precursor solution A to the precursor solution B is precursor solution A / precursor solution B=90:10-70:30.

[0010] According to the hydrogel precursor solution of the present invention, the photocrosslinking agent is one or more of 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone and 2,2-methoxy-2-phenylacetophenone.

[0011] According to the hydrogel precursor solution of the present invention, the concentration of polyethylene glycol diacrylate solution is 35-45wt.%; the concentration of gelatin solution is 5-15wt.%; the concentration of hyaluronic acid solution is 3-8wt.%; the concentration of chitosan solution is 1-2wt.%; and the concentration of starch solution is 20wt.%.

[0012] According to the hydrogel precursor solution of the present invention, the hydrogel precursor solution further comprises a coupling agent, and the coupling agent is N-hydroxysulfosuccinimide.

[0013] According to the hydrogel precursor solution of the present invention, the mass-to-volume ratio of the coupling agent to the precursor solution B is the mass of the coupling agent / the volume of the precursor solution B=10-20 mg:1 ml.

[0014] According to the hydrogel precursor solution of the present invention, based on the mass of the precursor solution A, the added amount of the photocrosslinking agent is 3-5‰.

[0015] According to the hydrogel precursor solution of the present invention, the hydrogel precursor solution also includes an ionic crosslinking agent, and the ionic crosslinking agent is one or more of a CaSO4 solution, a FeCl3 solution or a Ca(NO3)2 solution.

[0016] The present invention also provides a method for preparing the hydrogel precursor solution according to the present invention, comprising the following steps:

[0017] Mixing precursor solution A and precursor solution B to obtain a mixed solution;

[0018] Add photocrosslinker and mix well.

[0019] The present invention also provides a hydrogel, which is obtained by solidifying the hydrogel precursor solution of the present invention.

[0020] The present invention also provides a method for preparing the hydrogel according to the present invention, which is obtained by curing the hydrogel by ultraviolet light under vacuum conditions.

[0021] Effects of the Invention

[0022] The hydrogel of the present invention has high viscosity, biocompatibility and degradability, and when applied to dynamic, moist mucosa, it can stably adhere during the treatment period and degrade automatically after treatment; it is compatible with flexibility and stretchability: it has strong anatomical compliance and high stretchability, and can completely fit into grooves where conventional treatments cannot deliver drugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the hydrogel structure;

[0024] Figure 2 Adhesion energy test diagram of the hydrogel of Example 1;

[0025] Figure 3 The adhesion energy of the hydrogel of Example 1 changes with time;

[0026] Figure 4 Fourier transform infrared spectrum test graph of the hydrogel of Example 1;

[0027] Figure 5 Mechanical properties test diagram of the hydrogel of Example 1, (a) tension and (b) compression;

[0028] Figure 6 Scanning electron microscopy morphology of the hydrogel of Example 1;

[0029] Figure 7 Schematic diagram of in vitro degradation experiment of the hydrogel of Example 1;

[0030] Figure 8 Schematic diagram of hydrogel adhesion. DETAILED DESCRIPTION

[0031] The preparation method of the present invention will be described in further detail below in conjunction with specific examples. It should be understood that the following examples are only exemplary illustrations and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0032] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the reagents, materials, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels.

[0033] The present invention provides a hydrogel precursor solution, which comprises: a precursor solution A, a precursor solution B and a photocrosslinking agent, wherein the precursor solution A is a polyethylene glycol diacrylate solution, and the precursor solution B is a solution of one or more of gelatin, hyaluronic acid, sodium alginate, chitosan or starch.

[0034] Wherein, the mass ratio of the precursor solution A to the precursor solution B is precursor solution A / precursor solution B=90:10-70:30.

[0035] The sources of hydrogel viscosity are surface bonding anchoring and dissipation mechanism. The adhesion surface is bonded to the substrate surface through electrostatic interaction, covalent bonds, and physical interpenetration. The dissipation mechanism is that the double network matrix structure of the hydrogel dissipates energy through hysteresis. Therefore, when the crack generated by stress expands, the polymer at the front of the crack is tightened, and the stress is transmitted from the crack front to the inside of the matrix. The dissipation zone consumes a lot of energy as the topological entanglement and covalent bonds, hydrogen bonds, etc. of the untied double network matrix, thereby generating huge adhesion energy. Therefore, the adhesion energy of the hydrogel is contributed by two components, one is surface bonding, and the other is the dissipation mechanism. The introduction of the dissipation mechanism will increase the adhesion energy by 4-5 times compared to the structure with only surface anchoring.

[0036] In the present invention, the matrix material of the hydrogel is a double network topological entanglement network formed by polyethylene glycol diacrylate (PEGDA) and natural polymers. The first network uses the synthetic polymer PEGDA that provides stretchability, and the second network uses the natural polymer, which can form a network by itself, can form temporary cross-links with the tissue surface and has a certain viscosity. The topological entanglement realizes the dissipation mechanism, and both also form chemical bonds and van der Waals forces such as Michael addition, amidation reaction, hydrogen bonds, etc. with the tissue surface. At the same time, PEGDA acts as a spring-like stretchable frame to achieve both viscosity and toughness.

[0037] According to the hydrogel precursor solution of the present invention, the photocrosslinking agent is one or more of 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone and 2,2-methoxy-2-phenylacetophenone.

[0038] According to the hydrogel precursor solution of the present invention, the concentration of the polyethylene glycol diacrylate solution is 35-45wt.%, which can be obtained by stirring at room temperature;

[0039] The gelatin solution has a concentration of 5-15 wt.%, which can be obtained by heating to 60°C and stirring to dissolve;

[0040] The concentration of the hyaluronic acid solution is 3-8 wt.%, which can be obtained by stirring at room temperature overnight;

[0041] The concentration of chitosan solution is 1-2 wt.%, and can be obtained by using 2-(N-morpholino)ethanesulfonic acid (MES) buffer solution with pH=4.7 as solvent, heating to 60° C. and stirring;

[0042] The concentration of the starch solution is 20 wt.%, which can be obtained by heating to 60° C. and stirring to dissolve.

[0043] According to the hydrogel precursor solution of the present invention, the hydrogel precursor solution further comprises a coupling agent, and the coupling agent is N-hydroxysulfosuccinimide.

[0044] According to the hydrogel precursor solution of the present invention, the mass-to-volume ratio of the coupling agent to the precursor solution B is the mass of the coupling agent / the volume of the precursor solution B=10-20 mg:1 ml.

[0045] According to the hydrogel precursor solution of the present invention, based on the mass of the precursor solution A, the added amount of the photocrosslinking agent is 3-5‰.

[0046] According to the hydrogel precursor solution of the present invention, the hydrogel precursor solution also includes an ionic crosslinking agent, and the ionic crosslinking agent is one or more of a CaSO4 solution, a FeCl3 solution or a Ca(NO3)2 solution. Preferably, the ionic crosslinking agent is a CaSO4 solution with a concentration of 1-3wt.%, and is added in a ratio of 1:4-1:10 of the ionic crosslinking agent to the precursor solution B.

[0047] The present invention also provides a method for preparing the hydrogel precursor solution according to the present invention, comprising the following steps:

[0048] Mixing precursor solution A and precursor solution B to obtain a mixed solution;

[0049] Add photocrosslinker and mix well.

[0050] The present invention also provides a hydrogel, which is obtained by solidifying the hydrogel precursor solution of the present invention.

[0051] The present invention also provides a method for preparing the hydrogel according to the present invention, which is obtained by curing the hydrogel by ultraviolet light under vacuum conditions.

[0052] Example

[0053] Example 1

[0054] The raw materials were mixed in a ratio of PEGDA solution: gelatin solution: I-2959 solution (2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone): NHS powder (N-hydroxysulfosuccinimide) = 500 μL: 500 μL: 100 μL: 12 mg, wherein the concentration of the EGDA solution was 40 wt.%; the concentration of the gelatin solution was 10 wt.%; the mass volume ratio of the NHS powder to the precursor solution B was the mass of the NHS powder / the volume of the precursor solution B = 12 mg: 1 ml, and the amount of the I-2959 solution (2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone) added was 3‰. After being fully mixed, 1 mL of the mixed solution was drawn with a pipette and dropped into a 3 cm × 3 cm square PTFE mold, which was placed in a vacuum dryer and evacuated for 5 min. The PTFE mold was placed under a 365 nm ultraviolet curing lamp for curing for 20 min to obtain a hydrogel.

[0055] Example 2

[0056] Concentration of sodium alginate solution: 5wt.%;

[0057] Prepare a CaSO4 solution with a concentration of 2 wt.%, and stir at room temperature until the solution is in a state of a uniformly dispersed suspension.

[0058] Add the three solutions into the same syringe at a ratio of PEGDA solution: I-2959 solution: CaSO4 solution = 500μL: 100μL: 100μL, and then add 500μL of sodium alginate solution into another syringe. The two syringes are connected with a Luer connector, and the pistons on both sides are quickly pushed and pulled repeatedly to mix the solutions thoroughly. After mixing, the mixed solution is dripped into the PTFE mold, vacuumed for 5 minutes, and then heated at 60℃ for 2 minutes. Finally, the sample is placed under a 365nm UV curing lamp for 20 minutes.

[0059] Example 3

[0060] The concentration of the FeCl3 solution is 0.081 wt.%.

[0061] The concentration of the HA solution was 4 wt.%, and the mixture was stirred at room temperature overnight.

[0062] Mix the four solutions with PEGDA solution: HA solution: I-2959 solution: FeCl3 solution = 500μL: 500μL: 100μL: 100μL, add the three solutions into the same syringe, and then add 500μL HA solution into another syringe. The two syringes are connected with a Luer connector, and the pistons on both sides are pushed and pulled repeatedly to mix the solutions thoroughly. The mixed solution is dripped into the PTFE mold, vacuumed for 5 minutes, and then heated at 60℃ for 2 minutes. Finally, the sample is cured under a 365nm UV curing lamp for 20 minutes.

[0063] Performance Testing

[0064] Adhesion energy test

[0065] Adhesion energy test: The method used in the experiment to determine the adhesion energy of hydrogel is a 180° peel test. The stress-strain curve obtained from the test is calculated according to the formula

[0066]

[0067] The adhesion energy data of the material can be obtained by calculation. During the experiment, the hydrogel needs to be attached to the PET backing plate at all times to prevent it from being crushed by the clamp. The results are as follows Figure 2 shown.

[0068] The adhesion energy was tested on the 1st, 2nd, 3rd, 4th, 5th, 6th, 10th and 14th days respectively. The results are as follows Figure 3 shown.

[0069] Fourier Transform Infrared Spectroscopy Test

[0070] The test was carried out using German Netzsch X70 Fourier transform infrared spectrometer.

[0071] Tensile and compression properties testing

[0072] The tensile and adhesion energy of Example 1 were tested using an EZ-LX HS small-tonnage tensile testing machine produced by Shimadzu Corporation of Japan.

[0073] Tensile test: Before the experiment, the sample was cut into a dumbbell shape, and a PET plate of appropriate size was pasted on both sides of the wider part of the hydrogel end to prevent the sample from being crushed by the testing machine. During the experiment, the stretching rate was adjusted to 5mm / min and remained unchanged. The elongation at break of the material was calculated by the following formula. The 0-10% strain part of the stress-strain curve was taken for straight line fitting, and the slope of the fitting line was the elastic modulus of the material.

[0074]

[0075] Where, ΔL b It is the elongation within the gauge length when the specimen fails, and L0 is the initial gauge length.

[0076] The compression test was performed using the same instrument.

[0077] SEM Scanning Electron Microscope Test

[0078] A Mira3LMH SEM scanning electron microscope produced by TESCAN was used. The samples were freeze-dried for 24 hours before observation. To observe the cross-section of the samples, the freeze-dried samples were placed in liquid nitrogen for rapid cooling and embrittlement, and then the samples were immediately broken. A relatively flat cross-section was selected as the observation surface, facing upward, and the back of the sample was fixed on the sample stage with conductive glue. The appropriate observation area and magnification were selected in the field of view for SEM imaging. The results are shown in Figure 2. Figure 6 shown.

[0079] In vitro degradation test

[0080] Biodegradation: The sample size used for biodegradability testing in the experiment is designed according to the actual application scenario. The length and width are about 2cm×3cm, the thickness is about 1mm, and the initial wet weight W0 is about 0.3g. The specific operation is that after the sample preparation is completed, the material is soaked in a sufficient amount of PBS buffer and stored in a constant temperature and humidity chamber. Take it out at the same time every day, gently wipe off the obvious moisture on the surface of the sample, place it in the air for 20 minutes to allow the moisture on the surface of the sample to fully evaporate, and then weigh and record it as the wet weight W of the PG hydrogel after different days of degradation. T The degradation rate is expressed as the residual mass percentage of the hydrogel. Figure 7 The specific formula is:

[0081]

Claims

1. A hydrogel precursor solution comprising: Precursor solution A, precursor solution B and a photocrosslinking agent, wherein the precursor solution A is a polyethylene glycol diacrylate solution, the precursor solution B is a gelatin solution, and the photocrosslinking agent is one or more of 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone and 2,2-methoxy-2-phenylacetophenone. The hydrogel precursor solution also includes a coupling agent, The coupling agent is N-hydroxysulfosuccinimide, Wherein, the mass ratio of the precursor solution A to the precursor solution B is precursor solution A / precursor solution B=90:10-70:30; Based on the mass of the precursor solution A, the amount of the photocrosslinking agent added is 3-5‰; The mass volume ratio of the coupling agent to the precursor solution B is the mass of the coupling agent / the volume of the precursor solution B=10-20 mg:1 ml.

2. The hydrogel precursor solution according to claim 1, characterized in that: The concentration of the polyethylene glycol diacrylate solution is 35-45 wt. %; the concentration of the gelatin solution is 5-15 wt. %.

3. A method for preparing a hydrogel precursor solution according to claim 1 or 2, characterized in that: The following steps are included: Mixing precursor solution A and precursor solution B to obtain a mixed solution; Add photocrosslinker and mix well.

4. A hydrogel obtained by solidifying the hydrogel precursor solution according to claim 1 or 2.

5. A method for preparing a hydrogel according to claim 4, wherein the hydrogel precursor solution is cured by ultraviolet light under vacuum conditions to obtain a hydrogel.

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