Responsive antibacterial hydrogel coating-modified implants and methods of making

Abstract

The application discloses a kind of responsive antibacterial hydrogel coating modified implants and preparation method.The present application provides a kind of implant antibacterial hydrogel coating modification method, using hydrogel coating solution is modified implant by immersion, spin coating or spraying method, forms antibacterial coating on the surface of implant;The hydrogel coating solution is composed of tannic acid, 3-formyl phenyl boronic acid, tobramycin and deionized water according to weight ratio (30-60) :(40-70) :(20-45) :1000, pH value is 8.0-10.0.The modification method of the present application is simple in operation, raw material is easy to obtain, process flow is less, and the hydrogel coating does not need initiator and external stimulation, can be in situ gel on the surface of implant at normal temperature and pressure, also has pH, active oxygen stimulation responsiveness and excellent antibacterial performance, and the hydrogel coating of the present application has extensive substrate adhesion, and can be used on the surface of metal, ceramic or composite material etc..

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coating modified implants. More particularly, it relates to a responsive antibacterial hydrogel coating modified implant and a preparation method. BACKGROUND

[0002] Implants refer to implantable medical devices placed in body cavities caused by surgical operations or physiological existence, with a retention time of 30 days or more, commonly used for implant repair in dentistry and orthopedics. The most commonly used implant materials in dentistry and orthopedics are titanium and titanium alloys.

[0003] However, many implant materials, including titanium and titanium alloys, lack antibacterial properties, resulting in a high risk of bacterial infection due to the lack of antibacterial ability. Implant-related infections are one of the most common complications of bone repair surgery, which can easily cause implant loosening, poor bone integration, and other problems, ultimately leading to surgical failure. Therefore, an ideal bone implant should have antibacterial properties to minimize the risk of implant-related infections. Constructing a responsive antibacterial coating on the surface of the implant allows implants lacking antibacterial properties to have antibacterial ability and reduces the probability of implant-related infections. In addition, considering that bacterial infections after implant surgery are often accompanied by local acidification and a dramatic increase in reactive oxygen species, if the coating has pH and reactive oxygen species stimulus responsiveness and can release antibacterial substances on demand, it is more valuable for application.

[0004] Constructing an antibacterial coating on the surface of the implant has high practical value. The most critical issue in making an antibacterial coating is the adhesion of the coating to the implant (whether it is easy to peel off) and safety. Chinese patent CN116672512A discloses an antibacterial biological coating for medical devices, which comprises a porous photocrosslinked hydrogel and a blastomyces, wherein the blastomyces grows in the pores of the hydrogel. This scheme uses blastomyces to inhibit the adhesion of candida albicans to achieve the effect of resisting candida albicans. However, the preparation method of this coating is complex, and an initiator needs to be added and the coating can only be gelled under heating conditions during the preparation process. Moreover, the coating does not have pH and reactive oxygen species stimulus responsiveness. There is a lack of implant antibacterial coatings on the market that have simple and efficient antibacterial activity, stimulus responsiveness to pH and reactive oxygen species, strong adhesion to implants, controllable degradability, and good biocompatibility. SUMMARY

[0005] The present application aims to provide a method for modifying an implant with an antibacterial hydrogel coating, which realizes the bacteria-triggered on-demand release of antibacterial active substances by constructing a pH and reactive oxygen species responsive hydrogel coating, thereby improving the local concentration and efficacy of antibiotics and reducing antibiotic resistance. In addition, as the hydrogel coating gradually degrades, the underlying microstructure of the implant is exposed, which facilitates the migration, proliferation, differentiation and secretion of various proteins and minerals by osteoblasts to reconstruct the bone regeneration microenvironment and promote implant bone integration.

[0006] The first object of the present application is to provide a method for modifying an implant with an antibacterial hydrogel coating.

[0007] The second object of the present application is to provide a hydrogel coating modified implant prepared by the above method.

[0008] The above objects of the present application are achieved by the following technical solutions:

[0009] The present application provides a method for modifying an implant with an antibacterial hydrogel coating, which uses a hydrogel coating solution to modify the implant by immersion, spin coating or spraying to form an antibacterial coating on the surface of the implant; the hydrogel coating solution is composed of tannic acid, 3-formylphenylboronic acid, tobramycin and deionized water in a weight ratio of (30-60):(40-70):(20-45):1000, and the pH value is 8.0-10.0.

[0010] Preferably, the hydrogel coating solution is composed of tannic acid, 3-formylphenylboronic acid, tobramycin and deionized water in a weight ratio of (40-45):(50-55):(40-44):1000.

[0011] Preferably, the hydrogel coating solution is composed of tannic acid, 3-formylphenylboronic acid, tobramycin, graphene oxide and deionized water in a weight ratio of (30-60):(40-70):(20-45):(0.1-0.5):1000, and the pH value is 8.0-10.0.

[0012] Preferably, the hydrogel coating solution is composed of tannic acid, 3-formylphenylboronic acid, tobramycin, graphene oxide and deionized water in a weight ratio of (40-45):(50-55):(40-44):(0.1-0.3):1000.

[0013] Preferably, the immersion method is to immerse the implant in the coating solution for 30-60 s, repeated 3-5 times.

[0014] As an alternative embodiment, the implant is pre-treated before modification; the pre-treatment method comprises the following steps: surface roughening treatment of the implant, and then chemical modification activation treatment; the chemical modification activation treatment is soaking the implant in a basic buffer solution containing a phenolic compound, and then taking out and washing the surface with deionized water.

[0015] Preferably, the basic buffer solution containing a phenolic compound is a Tris buffer solution of 1-3 mg / mL dopamine hydrochloride, and the soaking time is 8-16 h.

[0016] As an alternative embodiment, the surface roughening treatment is any one or more of mechanical polishing, sandblasting, alkali heat treatment, acid etching, and high-energy beam etching treatment.

[0017] Preferably, the alkali heat treatment is soaking the implant in a 3-8 M NaOH solution, heat treatment at 50-70°C for 8-16 h, and then taking out the implant and washing with a large amount of deionized water to remove residual solution.

[0018] The hydrogel coating modified implant prepared by the above method.

[0019] Preferably, the material of the implant is metal, ceramic or polymer material.

[0020] Preferably, the metal is titanium or titanium alloy.

[0021] As an alternative embodiment, the product type of the implant includes dental implant, bone screw, bone plate, joint prosthesis, intervertebral disc fusion cage or three-dimensional porous scaffold.

[0022] As an alternative embodiment, the hydrogel coating modification method of the implant comprises the following steps:

[0023] Step (1): soaking the implant in a 3-8 M NaOH solution, heat treatment at 50-70°C for 8-16 h, and then taking out the implant and washing with deionized water to remove residual solution;

[0024] Step (2): soaking the implant treated in step (1) in a Tris buffer solution (pH 8.5) of 1-3 mg / mL dopamine hydrochloride for 8-16 h;

[0025] Step (3): soaking the implant treated in step (2) in the above implant-responsive antibacterial hydrogel coating solution for 30-60 s, and repeating 3-5 times.

[0026] The present application has the following beneficial effects:

[0027] The implant antibacterial hydrogel coating modification method provided by the application is simple to operate, raw materials are easy to obtain, the process flow is less, the formation of the hydrogel coating does not require an initiator and external stimulation, and the hydrogel can be formed in situ on the surface of the implant at normal temperature and pressure, and the hydrogel coating also has pH and active oxygen stimulation responsiveness and excellent antibacterial performance, can be rapidly responsive degradation and release active antibacterial substances. In the preparation of the hydrogel coating of the application, functional nanomaterials (such as graphene oxide) can be selectively added to endow the hydrogel coating with additional stimulus responsiveness (such as photothermal performance). The hydrogel in the implant antibacterial hydrogel coating modification method of the application has wide substrate adhesion, and can be used to construct a hydrogel coating on the surface of metal, ceramic or composite materials, and the method for modifying the implant is simple and fast. The implant modified by the hydrogel coating is responsive to the acid / active oxygen-rich microenvironment related to bacterial infection, can be rapidly responsive degradation and release active antibacterial substances (antibiotics and phenolic compounds). BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The preparation flow chart of the method for modifying the titanium implant with the hydrogel coating prepared in the application.

[0029] Figure 2 The Fourier transform infrared spectrogram of the hydrogel prepared in Example 1.

[0030] Figure 3 The titanium sheet modified by the hydrogel coating and the titanium scaffold modified by the hydrogel coating prepared in Example 2 (A is the titanium sheet modified by the hydrogel coating, and B is the titanium scaffold modified by the hydrogel coating).

[0031] Figure 4 The hydrogel coating and the titanium sheet modified by the hydrogel coating prepared in Example 3 (A is the hydrogel coating solution in a non-gel state, B is the hydrogel coating solution in a gel state after standing, C is the titanium sheet modified by the hydrogel coating, and D is the titanium sheet modified by the hydrogel coating after scratch test).

[0032] Figure 5 The hydrogel coating and the titanium sheet modified by the hydrogel coating prepared in Example 4 (A is the hydrogel coating solution in a non-gel state, B is the hydrogel coating solution in a gel state after standing, and C is the titanium sheet modified by the hydrogel coating).

[0033] Figure 6 The results of the co-culture liquid coating plate of the titanium scaffold treated in different ways and co-cultured with E. coli and S. aureus for 24 h.

[0034] Figure 7 The antibacterial circle diagram of the titanium sheet treated in different ways on E. coli and S. aureus.

[0035] Figure 8Scanning electron microscope results of the adhesion of bacteria on the surface of the pretreated titanium sheet and the hydrogel coated titanium sheet after co-culturing with E. coli and S. aureus respectively (A is the scanning electron microscope image of the material surface after co-culturing the pretreated titanium sheet with E. coli; B is the scanning electron microscope image of the material surface after co-culturing the pretreated titanium sheet with S. aureus; C is the scanning electron microscope image of the material surface after co-culturing the hydrogel coated titanium sheet with E. coli; D is the scanning electron microscope image of the material surface after co-culturing the hydrogel coated titanium sheet with S. aureus).

[0036] Figure 9 Results of the acid, alkali and active oxygen responsive degradation ability of the TPB hydrogel.

[0037] Figure 10 Graphene oxide-containing nanocomposite hydrogel prepared in Example 8.

[0038] Figure 11 Adhesion performance of the graphene oxide-containing nanocomposite hydrogel prepared in Example 8 to different substrate materials.

[0039] Figure 12 Results of the photothermal performance determination of the graphene oxide-containing hydrogel prepared in Example 8.

[0040] Figure 13 Comparison results of scratch test of titanium sheets coated with different hydrogels (A is the GelMA hydrogel coated titanium sheet before scratch test; B is the GelMA hydrogel coated titanium sheet after scratch test; C is the TPB hydrogel coated titanium sheet before scratch test; D is the TPB hydrogel coated titanium sheet after scratch test).

[0041] Figure 14 Bacteriostatic circle diagram of titanium sheets coated with different hydrogels (A is the result of the hydrogel coated titanium sheet prepared in Example 1, B is the result of the carboxymethyl chitosan hydrogel coated titanium sheet).

[0042] Figure 15 Results of scratch test of titanium sheets coated with different proportions of TPB (A is the hydrogel coated titanium sheet prepared in Comparative Example 1, B is the hydrogel coated titanium sheet prepared in Example 2).

[0043] Figure 16 Preparation results of different proportions of TPB hydrogel (A is 10 μL of deionized water, B is 1050 mg of 3-formylphenylboronic acid, C is the dissolution of 1050 mg of 3-formylphenylboronic acid and 0.85 mg of tannic acid in 10 μL of deionized water).

[0044] Figure 17Scratch test results of titanium sheets modified with TPB hydrogel prepared by dissolving 85 mg tannic acid, 200 mg 3-formylphenylboronic acid and 84 mg topromycin in 2000 μL of deionized water. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0046] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0047] The porous titanium alloy support was manufactured by Beijing Aikon Yicheng Co., Ltd.

[0048] The adhesion tester is manufactured by Huaguo Precision Instruments Co., Ltd., and its model number is QFH-HG600.

[0049] The preparation process of the implant-responsive antibacterial hydrogel coating solution and the method for modifying the implant of the present invention is as follows: Figure 1 As shown.

[0050] Tannic acid, CAS No.: 1401-55-4, structural formula: .

[0051] 3-Formylphenylboronic acid, CAS No.: 87199-16-4, Structural formula: .

[0052] Topromycin, CAS No.: 32986-56-4, Structural Formula: .

[0053] Example 1: Preparation of implant-responsive antibacterial hydrogel coating solution

[0054] The preparation method is as follows: Weigh 85 mg of tannic acid (TA), 105 mg of 3-formylphenylboronic acid (3-FPBA) and 84 mg of topromycin and dissolve them in 2000 μL (2000 mg) of deionized water. Adjust the pH value to 9.5 with 1 M NaOH until the three components are completely dissolved to obtain a hydrogel coating solution (which becomes TPB hydrogel after solidification).

[0055] Attenuated Total Reflectance Infrared Spectroscopy (ATR) The structure of the lyophilized TPB hydrogel was analyzed by FTIR. The Fourier transform infrared spectrum of the hydrogel is shown below. Figure 2 As shown, the results indicate that at 1312 cm -1 The presence of a B–O–C tensile vibration characteristic peak suggests the formation of a borate ester bond between tannic acid and 3-formylphenylboronic acid.

[0056] Example 2 Preparation of titanium sheet and titanium stent modified with responsive antibacterial hydrogel coating

[0057] Step (1): titanium sheet and titanium stent were immersed in 5M NaOH solution and heat treated at 60°C for 12 h. After taking out the titanium sheet and titanium stent, they were washed with a large amount of deionized water to remove residual solution;

[0058] Step (2): dopamine hydrochloride (2 mg / mL) was dissolved in Tris buffer solution (pH 8.5), and then the titanium sheet and titanium stent obtained in step (1) were immersed in it for reaction for 12 h, respectively; after taking out the titanium sheet and titanium stent, they were washed with a large amount of deionized water;

[0059] Step (3): the titanium sheet and titanium stent were immersed in the hydrogel solution prepared in Example 1 before gelation for 30-60 s, repeated 3-5 times, to obtain TPB hydrogel coating modified titanium sheet and TPB hydrogel coating modified titanium stent.

[0060] The TPB hydrogel coating modified titanium sheet and TPB hydrogel coating modified titanium stent are shown in Figure 3 After the above four steps, the titanium sheet and titanium stent surface are uniformly loaded with hydrogel coating.

[0061] Example 3 Preparation of implant responsive antibacterial hydrogel coating solution and titanium sheet modified with the same

[0062] The preparation method of the implant responsive antibacterial hydrogel coating solution is as follows: 60 mg of tannic acid (TA), 80 mg of 3-formylphenylboronic acid (3-FPBA) and 40 mg of tobramycin were dissolved in 2000 μL (2000 mg) of deionized water, and 1 M KOH was used to adjust the pH value to 8 to completely dissolve the three components to obtain a hydrogel coating solution (TPB hydrogel after solidification).

[0063] The TPB hydrogel coating modified titanium sheet was prepared according to the method of Example 2.

[0064] The implant responsive antibacterial hydrogel coating solution is shown in Figure 4 , and Figure 4 A of FIG. is the state of the hydrogel coating solution before gelation, and B of FIG. is the state of the hydrogel coating solution after gelation. The prepared TPB hydrogel coating modified titanium sheet is shown in Figure 4 C of FIG., and the titanium sheet surface is uniformly loaded with hydrogel coating. Scratch test was performed on the titanium sheet, and the test results are shown in Figure 4 D of FIG., and the titanium sheet coating did not appear obvious peeling off, indicating that the coating has good bonding force with the titanium sheet.

[0065] Example 4: Preparation of implant-responsive antibacterial hydrogel coating solution and its modified titanium sheet

[0066] The preparation method of implant-responsive antibacterial hydrogel coating solution is as follows: weigh 120 mg tannic acid (TA), 140 mg 3-formylphenylboronic acid (3-FPBA) and 90 mg topromycin and dissolve them in 2000 μL (2000 mg) of deionized water. Use 1 M Na2CO3 to adjust the pH value to 10 until the three components are completely dissolved to obtain the hydrogel coating solution (which becomes TPB hydrogel after solidification).

[0067] TPB hydrogel-coated modified titanium sheets were prepared according to the method in Example 2.

[0068] Implant-responsive antimicrobial hydrogel coating solutions, such as Figure 5 As shown, Figure 5 Figure A shows the hydrogel coating solution in its ungelled state. Figure 5 Figure B shows the gel-like state of the hydrogel coating solution after standing. The prepared TPB hydrogel-coated modified titanium sheet is shown below. Figure 5 As shown in Figure C, the titanium sheet surface is uniformly coated with a hydrogel coating. A scratch test was performed on the titanium sheet, and the results were similar to those in Example 3; no significant peeling or flaking of the coating was observed.

[0069] Example 5: Titanium scaffolds with different treatments against Escherichia coli (E. coli) Escherichia coli ) and Staphylococcus aureus ( Staphylococcus aureus Evaluation of antibacterial properties

[0070] (I) Experimental Methods

[0071] The TPB hydrogel-coated modified titanium scaffold was prepared according to the method of Example 2, and the titanium scaffold pretreated by alkaline heat treatment (pretreated titanium scaffold) was prepared according to the method of step (1) of Example 2.

[0072] Escherichia coli and Staphylococcus aureus were cultured to the logarithmic growth phase (OD = 0.6–0.8), and then the bacterial suspensions were diluted to 10⁻⁶. 7 CFU / mL, bare titanium scaffolds, TPB hydrogel-coated titanium scaffolds, and titanium scaffolds pretreated with alkali heat were each inoculated with 2 mL of bacterial solution and cultured for 24 h. The experiment was repeated 3 times.

[0073] After the culture was completed, the co-culture solution was diluted and plated for counting to characterize the antibacterial properties. Pure bacterial culture solution was plated as a control group.

[0074] (II) Experimental Results

[0075] The co-culture liquid after the titanium stents of different treatments (bare titanium group, pretreated titanium group, TPB hydrogel coating modified titanium group) were co-cultured with E. coli and S. aureus for 24 h was coated and plated as shown in Figure 6 The results show that the TPB hydrogel coating modified titanium stent (shown as TPB hydrogel coating titanium group in the figure) has excellent performance against E. coli and S. aureus, while the other treatments (bare titanium group, pretreated titanium group) have poor antibacterial performance.

[0076] Example 6 Evaluation of the antibacterial performance of titanium sheets of different treatments against E. coli and S. aureus

[0077] (I) Experimental method

[0078] The TPB hydrogel coating modified titanium sheet was prepared according to the method of Example 2, and the titanium sheet pretreated by alkali heat (pretreated titanium sheet) was prepared according to the method of step (1) of Example 2.

[0079] E. coli and S. aureus were cultured to the logarithmic growth phase (OD = 0.6-0.8) respectively to obtain the logarithmic growth phase bacterial solution.

[0080] The logarithmic growth phase bacterial solution was diluted and plated, and the titanium sheet, pretreated titanium sheet and TPB hydrogel coating modified titanium sheet were placed in the plate respectively, and cultured for 24 h. The experiment was repeated 3 times, and the antibacterial performance was characterized by the size of the inhibition zone.

[0081] The logarithmic growth phase bacterial solution was diluted to 10 7 CFU / mL, and then 1 mL of the diluted bacterial solution was taken and co-cultured with the titanium sheet, pretreated titanium sheet and TPB hydrogel coating titanium sheet for 24 h. The titanium sheet after co-culture was washed, fixed and gradient dehydrated for scanning electron microscope observation.

[0082] (II) Experimental results

[0083] The inhibition zone results of titanium sheets of different treatments (titanium sheet group, pretreated titanium sheet group and TPB hydrogel coating modified titanium sheet group) against E. coli and S. aureus are shown in Figure 7 The results show that the TPB hydrogel coating modified titanium sheet has excellent performance against E. coli and S. aureus. The inhibition zone diameter of the TPB hydrogel coating modified titanium sheet against E. coli is about 27.1 mm, and the inhibition zone diameter against S. aureus is about 35.6 mm.

[0084] The scanning electron microscope results of the bacterial adhesion on the surface of the pretreated titanium sheet and the TPB hydrogel coating titanium sheet after co-culture with E. coli and S. aureus are shown in Figure 8As shown, the results indicate that Escherichia coli and Staphylococcus aureus grow well on the pretreated titanium sheet material, while the bacterial membranes of Escherichia coli and Staphylococcus aureus on the TPB hydrogel-coated titanium sheet are damaged and die.

[0085] Example 7: Responsive degradation performance of hydrogels against acids, alkalis, and reactive oxygen species

[0086] (I) Experimental Methods

[0087] A hydrogel solution was prepared according to Example 1. The hydrogel solution was dispersed evenly using a vortex mixer and allowed to stand for 10-30 min to obtain TPB hydrogel. 1 M HCl, 1 M NaOH, and 1 M H2O2 were added to the TPB hydrogel, and the mixture was allowed to stand for a sufficient reaction. The phenomena were then observed.

[0088] (II) Experimental Results

[0089] The results of TPB hydrogel's responsive degradation ability to acids, alkalis, and reactive oxygen species are as follows: Figure 9 As shown, the results indicate that TPB hydrogels degrade under acid, alkali, and reactive oxygen species conditions, exhibiting multiple responsiveness.

[0090] Example 8: Preparation of a responsive antibacterial hydrogel coating solution loaded with graphene oxide and evaluation of its adhesion and photothermal properties.

[0091] (I) Preparation of graphene oxide-containing nanocomposite hydrogels

[0092] Prepare a 0.2 mg / mL aqueous solution of graphene oxide (GO). Then, weigh out 85 mg of tannic acid, 105 mg of 3-formylphenylboronic acid, and 84 mg of topromycin and dissolve them in 2 mL of GO aqueous solution. Adjust the pH to 9.5 with 1 M NaOH until completely dissolved to obtain a nanocomposite hydrogel solution containing graphene oxide. Use a vortex mixer to disperse the nanocomposite hydrogel solution containing graphene oxide evenly to obtain a hydrogel solution containing GO. Let it stand for about 10 minutes to form a gel, and obtain a nanocomposite hydrogel containing graphene oxide.

[0093] (II) Performance test results of graphene oxide-containing nanocomposite hydrogels

[0094] Nanocomposite hydrogels containing graphene oxide, such as Figure 10 As shown, the results indicate that the introduction of graphene oxide does not affect the gelation of the solution.

[0095] The adhesion performance of graphene oxide-containing nanocomposite hydrogels to different substrate materials is as follows: Figure 11 As shown, the results indicate that the graphene oxide-containing nanocomposite hydrogel still exhibits strong adhesion to metal, glass, and plastic substrates after gelation.

[0096] The photothermal performance of the hydrogel containing graphene oxide was determined, and the results, as shown in Figure 12 Fig. 2, show that the hydrogel has excellent light responsiveness and photothermal conversion performance after the introduction of graphene oxide, and the temperature can reach 50℃ after 6 min of irradiation with 808 nm near-infrared light.

[0097] Comparative Example 1

[0098] (I) Experimental method

[0099] A methylacrylated gelatin containing a photoinitiator 2959 was coated on the surface of a titanium sheet and crosslinked by ultraviolet light to form a hydrogel (GelMA coating), thereby obtaining a GelMA hydrogel coating modified titanium sheet.

[0100] The GelMA hydrogel coating modified titanium sheet was compared with the TPB hydrogel coating modified titanium sheet prepared in Example 2.

[0101] The scratch test was performed on the two different hydrogel coating modified titanium sheets using an adhesion tester, and the coating peeling condition was photographed.

[0102] (II) Experimental results

[0103] The comparison results of the scratch test of the titanium sheets modified with different hydrogels are shown in Figure 13 Fig. 3, which shows that the GelMA hydrogel coating on the surface of the GelMA hydrogel coating modified titanium sheet is obviously peeled off and peeled off before and after the scratch, while the TPB hydrogel coating modified titanium sheet of the present application does not have obvious peeling off. It is shown that the TPB hydrogel as a coating has better adhesion than the common GelMA.

[0104] Comparative Example 2

[0105] (I) Experimental method

[0106] 2wt% carboxymethyl chitosan was dissolved in 1vol% acetic acid solution, the pH value was adjusted to 6~7, then 0.1~0.5mol / L zinc chloride solution was added to form a gel on the titanium sheet, thereby obtaining a carboxymethyl chitosan hydrogel coating modified titanium sheet.

[0107] The carboxymethyl chitosan hydrogel coating modified titanium sheet was compared with the TPB hydrogel coating modified titanium sheet prepared in Example 2.

[0108] E. coli and S. aureus were respectively cultured to logarithmic growth phase (OD = 0.6-0.8) to obtain logarithmic growth phase bacterial solution. The logarithmic growth phase E. coli bacterial solution was diluted and plated, and the TPB hydrogel coating modified titanium sheet and the carboxymethyl chitosan hydrogel coating modified titanium sheet were placed in the plate and cultured for 24 h, and the antibacterial performance was characterized by the size of the inhibition zone.

[0109] (II) Experimental results

[0110] The inhibition zone diagram of the titanium sheet modified by different hydrogel coatings is shown in Figure 14 The carboxymethyl chitosan hydrogel coating modified titanium sheet did not appear obvious inhibition zone, while the TPB hydrogel coating modified titanium sheet had obvious inhibition zone with a diameter of about 24.4 mm. It is proved that the TPB hydrogel as a coating can maintain better antibacterial performance compared with the common antibacterial carboxymethyl chitosan hydrogel.

[0111] Comparative Example 3

[0112] The preparation method of the responsive antibacterial hydrogel coating modified titanium sheet of the present comparative example is different from that of Example 2 in that the amount of tobramycin is adjusted to 170 mg, and other conditions are the same as those of Example 2.

[0113] The scratch test of the TPB hydrogel coating modified titanium sheet prepared in the present comparative example and the TPB hydrogel coating modified titanium sheet prepared according to the preparation method of Example 2 was carried out.

[0114] The scratch test results of the TPB hydrogel coating modified titanium sheet prepared in the present comparative example are shown in Figure 15 A diagram of FIG., and the results show that the hydrogel coating of the present comparative example has poor bonding force, and the hydrogel coating has cracking, peeling and falling off.

[0115] The scratch test results of the TPB hydrogel coating modified titanium sheet prepared according to the preparation method of Example 2 are shown in Figure 15 B diagram of FIG., and the results show that the hydrogel coating modified titanium sheet prepared according to the preparation method of Example 2 does not have obvious peeling and falling off, indicating that the coating has good bonding force with the titanium sheet.

[0116] Comparative Example 4

[0117] The present comparative example explores the preparation of different proportions of TPB hydrogel coating solution.

[0118] (1) The test shows that when the amount of tannic acid (TA) is greater than 0.25 g and the amount of 3-formylphenylboronic acid (3-FPBA) is greater than 1 g, it cannot be completely dissolved in 1 mL of deionized water.

[0119] For example, as Figure 16As shown, 0.85 mg tannic acid (TA), 1050 mg 3-formylphenylboronic acid (3-FPBA) were added into 10 μL (10 mg) deionized water, and completely insoluble, unable to prepare the hydrogel coating solution of the present application.

[0120] (2) Test showed that when tannic acid, 3-formylphenylboronic acid, tobramycin and deionized water were mixed in a weight ratio of (30-60):(40-70):(20-45):1000, and the pH was adjusted to 8.0-10.0, the obtained hydrogel coating solution could better combine with titanium sheet and titanium stent, and was not prone to peeling phenomenon.

[0121] For example, 85 mg tannic acid, 200 mg 3-formylphenylboronic acid and 84 mg tobramycin were dissolved in 2000 μL (2000 mg) deionized water, and the pH was adjusted to 9.5 using 1 M NaOH, and the three components were completely dissolved to obtain a hydrogel coating solution (TPB hydrogel after coagulation). The titanium sheet was modified with the hydrogel coating solution according to the method of Example 2. Scratch test was performed according to the method of Comparative Example 1, and the combination of the coating and the modified titanium sheet was observed. The results are shown in Table 1. Figure 17 As shown, the coating of the modified titanium sheet showed obvious peeling and falling off phenomenon.

[0122] The above examples are preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods, and are all included in the protection scope of the present application.

Claims

1. A method for modifying titanium implants with an antibacterial hydrogel coating, characterized in that, An antibacterial coating is formed on the surface of an implant by means of soaking, spin coating, or spraying using a hydrogel coating solution; the hydrogel coating solution is composed of tannic acid, 3-formylphenylboronic acid, topromycin, and deionized water in a weight ratio of (30~60):(40~70):(20~45):1000, and has a pH value of 8.0~10.0; Before modification, the implant undergoes pretreatment; The pretreatment method includes the following steps: roughening the surface of the implant, followed by chemical modification and activation treatment; the chemical modification and activation treatment involves immersing the implant in an alkaline buffer solution containing phenolic compounds, removing it after immersion, and rinsing the surface with deionized water; the alkaline buffer solution containing phenolic compounds is a Tris buffer solution of 1~3 mg / mL dopamine hydrochloride, and the immersion time is 8~16 h; The surface roughening treatment is any one or more of mechanical grinding, sandblasting, alkaline heating, acid etching, and high-energy beam etching; the alkaline heating treatment is to immerse the implant in a 3-8M NaOH solution and heat it at 50-70℃ for 8-16 h, and then wash it with a large amount of deionized water to remove the residual solution after removing the implant.

2. A method for modifying titanium implants with an antibacterial hydrogel coating, characterized in that, An antibacterial coating is formed on the surface of an implant by means of soaking, spin coating, or spraying using a hydrogel coating solution. The hydrogel coating solution is composed of tannic acid, 3-formylphenylboronic acid, topromycin, graphene oxide, and deionized water in a weight ratio of (30~60):(40~70):(20~45):(0.1~0.5):1000, with a pH value of 8.0~10.

0. Before modification, the implant undergoes pretreatment; The pretreatment method includes the following steps: roughening the surface of the implant, followed by chemical modification and activation treatment; the chemical modification and activation treatment involves immersing the implant in an alkaline buffer solution containing phenolic compounds, removing it after immersion, and rinsing the surface with deionized water; the alkaline buffer solution containing phenolic compounds is a Tris buffer solution of 1~3 mg / mL dopamine hydrochloride, and the immersion time is 8~16 h; The surface roughening treatment is any one or more of mechanical grinding, sandblasting, alkaline heating, acid etching, and high-energy beam etching; the alkaline heating treatment is to immerse the implant in a 3-8M NaOH solution and heat it at 50-70℃ for 8-16 h, and then wash it with a large amount of deionized water to remove the residual solution after removing the implant.

3. The method according to claim 1 or 2, characterized in that, The soaking method is as follows: the implant is soaked in the coating solution for 30-60 seconds, and repeated 3-5 times.

4. Antibacterial hydrogel-coated modified titanium implants prepared by any of the methods described in claims 1 to 3.

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